WO2018230609A1 - Electric power steering apparatus - Google Patents
Electric power steering apparatus Download PDFInfo
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- WO2018230609A1 WO2018230609A1 PCT/JP2018/022597 JP2018022597W WO2018230609A1 WO 2018230609 A1 WO2018230609 A1 WO 2018230609A1 JP 2018022597 W JP2018022597 W JP 2018022597W WO 2018230609 A1 WO2018230609 A1 WO 2018230609A1
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- WIPO (PCT)
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- steering
- value
- steering angle
- command value
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
- H02P29/20—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors for controlling one motor used for different sequential operations
Definitions
- the present invention has a switching function between a steering angle control mode (automatic steering control mode such as parking assistance) and an assist control mode (manual steering control mode) in steering control of a vehicle, and drives a motor by a motor current command value.
- a steering angle control mode automated steering control mode such as parking assistance
- an assist control mode manual steering control mode
- a gradual change with a gradual gain is used to switch from the steering angle control mode to the assist control mode and from the assist control mode to the steering angle control mode.
- manual input determination is performed without erroneous determination, so that the shift to the assist control mode smoothly and reliably is performed, and unintended steering wheel fluctuations with respect to the motor current command value are suppressed.
- the present invention relates to a high-performance electric power steering device that reduces a sense of incongruity to a driver.
- An electric power steering device that applies a steering assist force (assist force) to a steering mechanism of a vehicle by a rotational force of a motor is provided with a steering shaft by a transmission mechanism such as a gear or a belt via a speed reducer.
- a steering assist force is applied to the rack shaft.
- Such a conventional electric power steering apparatus performs feedback control of the motor current in order to accurately generate the torque of the steering assist force.
- the motor applied voltage is adjusted so that the difference between the steering assist command value (current command value) and the motor current detection value is small. This is done by adjusting the duty of modulation) control.
- a column shaft (steering shaft, handle shaft) 2 of a handle (steering wheel) 1 is a reduction gear 3, universal joints 4 a and 4 b, and a pinion rack mechanism 5.
- the tie rods 6a and 6b are connected to the steering wheels 8L and 8R via the hub units 7a and 7b.
- the column shaft 2 is provided with a steering angle sensor 14 for detecting the steering angle ⁇ r of the handle 1 and a torque sensor 10 for detecting the steering torque Th, and a motor 20 for assisting the steering force of the handle 1 is a reduction gear.
- 3 is connected to the column shaft 2 through 3.
- the control unit (ECU) 30 that controls the electric power steering device is supplied with electric power from the battery 13 and also receives an ignition key signal IG via the ignition key 11.
- the control unit 30 calculates a current command value for assist control based on the steering torque Th detected by the torque sensor 10 and the vehicle speed Vs detected by the vehicle speed sensor 12, and a voltage obtained by compensating the current command value.
- the current supplied to the motor 20 is controlled by the control command value Vref.
- the steering angle ⁇ r is detected from the steering angle sensor 14, it can also be obtained from a rotation sensor such as a resolver connected to the motor 20.
- the control unit 30 is connected to a CAN (Controller Area Network) 40 that exchanges various vehicle information, and the vehicle speed Vs can be received from the CAN 40.
- the control unit 30 can be connected to a non-CAN 41 that exchanges communications, analog / digital signals, radio waves, and the like other than the CAN 40.
- the control unit 30 is mainly composed of a CPU (Central Processing Unit) (including MPU (Micro Processor Unit) and MCU (Micro Controller Unit)), but it shows general functions executed by programs inside the CPU. As shown in FIG.
- CPU Central Processing Unit
- MPU Micro Processor Unit
- MCU Micro Controller Unit
- the function and operation of the control unit 30 will be described with reference to FIG. 2.
- the steering torque Th detected by the torque sensor 10 and the vehicle speed Vs detected by the vehicle speed sensor 12 (or from the CAN) are expressed as a current command value Iref1.
- the current command value calculation unit 31 to be calculated is input.
- the current command value calculation unit 31 calculates a current command value Iref1, which is a control target value of the current supplied to the motor 20, using an assist map or the like based on the input steering torque Th and vehicle speed Vs.
- the current command value Iref1 is input to the current limiting unit 33 through the adding unit 32A, and the current command value Iref3 whose maximum current is limited by the overheat protection condition is input to the subtracting unit 32B, and the motor current value Im being fed back
- the voltage control command value Vref whose characteristics are improved by the PI control unit 35 is input to the PWM control unit 36, and the motor 20 is PWM driven via an inverter 37 as a drive unit.
- the current value Im of the motor 20 is detected by the motor current detector 38 and fed back to the subtraction unit 32B.
- a rotation sensor 21 such as a resolver is connected to the motor 20, and the actual steering angle ⁇ s is detected.
- the adder 32A is added with the compensation signal CM from the compensator 34, and the compensation of the system system is performed by adding the compensation signal CM so as to improve the convergence and inertia characteristics.
- the compensator 34 adds the self-aligning torque (SAT) 343 and the inertia 342 by the adder 344, further adds the convergence 341 to the addition result by the adder 345, and the addition result of the adder 345 is the compensation signal CM. It is said.
- a general electric power steering apparatus having a control function of a steering angle control mode and an assist control mode and having a function of switching the steering control mode will be described with reference to FIG. 3.
- a motor 150 detects a motor rotation angle ⁇ s.
- a rotation sensor 151 such as a resolver is connected, and the motor 150 is driven and controlled via the vehicle side ECU 130 and the EPS side ECU 140.
- the vehicle-side ECU 130 is configured to output a switching command unit 131 that outputs a switching command SW for the steering angle control mode or the assist control mode based on a button, a switch, or the like indicating the driver's intention, and a signal such as a camera (image) or a laser radar.
- a steering angle command value generation unit 132 that generates a steering angle command value ⁇ ref that becomes the target steering angle ⁇ t.
- the actual steering angle ⁇ r detected by the steering angle sensor 14 provided on the column shaft is input to the steering angle control unit 200 in the EPS side ECU 140 via the ECU 130.
- the switching command unit 131 receives a signal for identifying that the steering angle control mode is entered, for example, a vehicle state signal by a button or a switch provided on the dashboard or around the steering wheel, or a parking mode provided for a shift. Based on this, the switching command SW is output, and the switching command SW is input to the switching unit 142 in the EPS side ECU 140.
- the steering angle command value generation unit 132 generates a steering angle command value ⁇ ref by a known method based on data such as a camera (image) and a laser radar, and the generated steering angle command value ⁇ ref is a target steering angle ⁇ t. To the rudder angle control unit 200 in the EPS side ECU 140.
- the EPS-side ECU 140 outputs an assist control command value Itref calculated based on the steering torque Th and the vehicle speed Vs, and based on the steering torque Th, the target steering angle ⁇ t, the actual steering angle ⁇ r, and the motor angular speed ⁇ r.
- the motor angular velocity calculation unit 144 includes a low-pass filter (LPF) for cutting high-frequency noise after the calculation equivalent to differentiation.
- LPF low-pass filter
- the steering angle control unit 200 outputs a steering angular speed command value ⁇ c so that the actual steering angle ⁇ r follows the target steering angle ⁇ t, and the steering angular speed command value ⁇ c.
- the speed control unit 220 outputs a steering angle control command value Imref so as to follow ⁇ r.
- the switching unit 142 is based on a switching command SW from the switching command unit 131 of the vehicle-side ECU 130, and an assist control mode (manual steering control) by the assist control unit 141 and a steering angle control mode (by the steering angle control unit 200). Position / speed control mode), the assist control command value Itref is output in the assist control, and the steering angle control command value Imref is output in the steering angle control.
- the steering angle control command value and the assist control command value are multiplied by a gradual gain, and the steering mode is gradually switched to suppress sudden fluctuations in the motor current command value.
- the steering angle control command value is limited by the gradual gain during switching and is output to the motor current command value. Therefore, an output corresponding to the current command value limited to the steering angle control command value is output. It gets smaller. Due to this restriction, the actual steering angular speed of the motor becomes slower than the steering angular speed command value, so that a deviation occurs between the steering angular speed command value and the actual steering angular speed, and the integrated value of I control in the speed control is accumulated.
- Patent Document 1 proposes a method of controlling the steering angle speed to be gradually increased at the start of the steering angle control and reducing a sense of discomfort to the driver due to a sudden change in the steering wheel at the start.
- Patent Document 1 has a problem that when the gradual change starts, it continues to increase until the upper limit is reached, so that the integral value of I control accumulates excessively.
- the steering angle control is stopped when the driver operates the steering wheel during the steering angle control mode and it is determined that the steering torque exceeds a predetermined value set in advance.
- the steering wheel is turned on when the torque sensor noise or when the tire steps on a pebble or when the steering angle control by the motor is performed.
- the output of the torque sensor may temporarily exceed a predetermined value due to the inertia torque, and the steering angle control is stopped each time.
- the steering angle control mode and the assist control mode interfere with each other, which not only gives the driver a sense of incongruity, but also allows the driver to handle the steering wheel during the steering angle control. Even if is operated, the steering angle control may not be stopped immediately.
- Patent Document 2 Japanese Patent No. 3845188
- the apparatus disclosed in Patent Document 2 detects a movement trajectory setting means for storing or calculating a movement trajectory of a vehicle up to a target position, an actuator (motor) for turning a wheel, and a steering torque applied to a steering wheel by a driver.
- the driving torque of the actuator is controlled based on the movement torque set by the steering torque detection means (torque sensor) and the movement locus setting means, and a steering torque greater than a predetermined value is detected over a predetermined time.
- a vehicle automatic steering apparatus having an actuator control means for stopping the control of the actuator based on the movement trajectory when set, a plurality of predetermined values are set, and the predetermined time is changed corresponding to each predetermined value It has become.
- Patent Document 3 shows that the application range of the conventional automatic steering technology is expanded to a low speed region, and that operability, safety and comfort related to the steering operation during driving are ensured. Is switched to the torque control method by the steering torque threshold value determination means.
- the switching condition in Patent Document 3 is when the value of the steering torque ⁇ exceeds the constant ⁇ 0 (steering torque determination threshold) for N + 1 consecutive times, and takes the absolute value of the steering torque, and the absolute value is the torque threshold value.
- ⁇ 0 steering torque determination threshold
- Patent Document 4 is an obstacle avoidance assistance device that determines that the assist steering force of the host vehicle is released when it is detected that the steering force of the driver exceeds the force to hold the steering against the assist steering force. Yes, Patent Document 4 discloses that an integrated value of the steering torque after the steering torque exceeds a predetermined reference threshold is calculated. However, Patent Document 4 is the integral of the steering torque in the portion exceeding the reference threshold, and is not related to the absolute value of the steering torque. Further, Patent Document 5 relates to an automatic steering device that prevents a steering wheel from being suddenly lightened at the moment when a control state of a motor that steers a wheel is switched. Is set. However, the integration of Patent Document 5 relates to the vehicle speed and the yaw rate, and unlike the integration of the steering torque, the second threshold needs to be set in the dead zone region.
- the present invention has been made under the circumstances described above, and an object of the present invention is to provide a gradual gain for switching from the steering angle control mode to the assist control mode and from the assist control mode to the steering angle control mode. Using the absolute value and the integral of the entire signal, the manual input is judged even during the rudder angle control mode to smoothly shift to the assist control mode, and the motor current command value is An object of the present invention is to provide a highly functional electric power steering device that suppresses unintended steering wheel fluctuations and reduces the uncomfortable feeling to the driver.
- the present invention has a function of switching between an assist control mode and a steering angle control mode by a switching command, and includes a first assist control command value calculated by the assist control unit and a first rudder calculated by the steering angle control unit.
- An electric power steering apparatus that generates a motor current command value with an angle control command value, drives the motor with the motor current command value, and assists the steering system of the vehicle, and the object of the present invention is to provide the steering torque and the Based on the switching command, a speed command gradual change gain and a speed control gradual change gain used in the position / speed control of the steering angle control, and a steering angle control output gradual change gain and an assist control output gradual change gain used when switching the control mode.
- a switching determination / gradual gain generating unit for generating the steering angle control unit inputs a steering angle command value as a target steering angle, and based on an angular deviation between the target steering angle and the actual steering angle
- a position control unit that outputs an angular velocity command value
- a gradual change limiting unit that gradually changes the rudder angular velocity command value according to the speed command gradual change gain
- a steering angular speed control unit that processes a target steering angular speed output from the control unit based on an actual steering angular speed and the speed gradual gain, and a speed control current value output from the steering angular speed control unit.
- a first gradual change output unit that gradually changes with a variable gain and outputs a second steering angle control command value, and the first assist control command value output from the assist control unit is controlled by the assist control.
- a second gradual change output unit that gradually changes with an output gradual change gain and outputs a second assist control command value is provided, based on the second steering angle control command value and the second assist control command value.
- the gradual gain generating unit has a manual input determining unit, which compares the LPF that filters the steering torque with the absolute value of the steering torque that has passed through the LPF, and a torque threshold value.
- a torque value comparison unit that outputs as a signal, an integral calculation unit that integrates the entire output signal and outputs the integral output value, This is achieved by comprising a switching determination unit that outputs a steering torque determination signal.
- the steering angle control command value is gradually changed by the steering angle control output gradual change gain
- the assist control command value is gradually changed by the assist control output gradual change gain. Since the angular velocity command value and the steering angle control current value are gradually changed with the speed command gradual change gain and the speed control gradual change gain, respectively, and the vibration damping signal subjected to the handle vibration damping process is added to the steering angle control command value, smooth Mode switching is possible, unintentional fluctuations in the steering wheel with respect to the motor current command value can be suppressed, and discomfort to the driver can be reduced.
- FIG. 5 is a diagram schematically illustrating a problem when a limiter is not used. It is a diagram which illustrates typically the effect at the time of using a limiter.
- the present invention gradually changes the steering angle control command value with the steering angle control output gradual gain, gradually changes the assist control command value with the assist control output gradual gain, and the steering angular velocity from the position control unit in the steering angle control unit.
- the command value is gradually changed with the speed command gradual gain, and the upper and lower limits of the steering angular velocity command value after the gradual change are input to the steering angular velocity control unit with the target rudder angular velocity limited by the limiter according to the speed command gradual gain.
- the rudder angular speed control unit further performs control calculation based on the target rudder angular speed and the actual rudder angular speed, and gradually changes with a speed control gradual change gain to output a speed control current value. Is added to the speed control current value to output a steering angle control command value.
- a switching determination / gradual change gain generation unit for inputting a steering torque and a switching command.
- the switching determination / gradual change gain generation unit is based on the steering torque and the switching command.
- a control gradual gain, a steering angle control output gradual gain, and an assist control output gradual gain are generated.
- the speed command gradual change gain and the speed control gradual change gain are used for position speed control in the steering angle control unit, and the steering angle control output gradual change gain and the assist control output gradual change gain are used when the control mode is switched.
- Each of these gradually changing gains is generated using a manual input determination unit that determines a manual input based on the steering torque.
- the manual input determination unit obtains an absolute value of the steering torque through the LPF and is not related to the steering direction.
- the entire absolute value is integrated, the absolute value is compared with the torque threshold value, and when the absolute value is equal to or greater than the torque threshold value, the integral calculation of the entire absolute value is started, and the integrated value is compared with the integral threshold value to determine the torque. A judgment signal is obtained.
- a pre-processing unit that performs limit processing and rate limit processing on the steering angle command value and removes steering wheel vibration is provided in the front stage of the steering angle control unit (or in the steering angle control unit). Since the position / speed control is performed on the pre-processed target rudder angle, there is no sense of incongruity even when the steering wheel is suddenly steered. Further, in an embodiment in which a steering wheel vibration removing unit and a feed forward (FF) filter are provided in the position control unit in the steering angle control unit, a steering angle control command value that suppresses steering vibration (around 10 Hz) can be generated.
- FF feed forward
- the steering angle control command value from the steering angle control unit is gradually changed by multiplying the steering angle control output gradual change gain, and the assist control output gradual change gain is applied to the assist control command value from the assist control unit.
- the steering angle control output gradual change gain and the assist control output gradual change gain have opposite increase and decrease characteristics.
- the steering angle control output gradual change gain and the assist control output gradual change gain are set at respective ratios (the steering angle control output gradual change gain is 0.0 (0%) to 1.0 (100%),
- the assist control output gradual change gain is 1.0 (100%) to 0.0 (%)) in principle in a relationship of 1.0, that is, 100%, and vice versa. (Non-linear) characteristics.
- the steering angle control output gradual gain and the assist control output gradual gain increase and decrease in the opposite relationship, but during the steering angle control mode, the total value of both is 1.0 (100%). Not necessarily.
- FIG. 5 shows an example of the configuration of the present invention corresponding to FIG. 3.
- a steering torque Th and a switching command SW are newly input to make a switching determination, and for gradual speed change in steering angle control.
- Gradual change gain SG (SG1, SG2) and gradual change gain SWG (SWG1, SWG2) for gradual change of control mode are output and managed, and a rudder in the vehicle-side ECU 130
- a pre-processing unit 500 that processes the steering angle command value ⁇ ref from the angle command value generation unit 132 and outputs the target steering angle ⁇ t is provided.
- the gradual change gain SG (SG1, SG2) for gradual speed change is input to the steering angle control unit 200, and the gradual change gain SWG (SWG1, SWG2) for mode change gradual change is input to the switching unit 142.
- the switching determination / gradual gain generating unit 400 is configured as shown in FIG. 6, for example, and includes a manual input determining unit 410 that inputs a steering torque Th and outputs a torque determination signal TD described later, a steering torque Th, and a torque determination.
- a gradual gain generator 430 that generates and outputs a speed command gradual change gain SG1 and a speed control gradual change gain SG2 based on the signal TD and the switching command SW, and a steering angle control based on the torque determination signal TD and the switching command SW.
- a gradual change gain switching generator 420 that calculates and outputs the output gradual change gain SWG1 and the assist control output gradual change gain SWG2.
- the switching command SW instructs switching from the steering angle control mode to the assist control mode, or switching from the assist control mode to the steering angle control mode, and the torque determination signal TD is obtained when the steering wheel is steered during the steering angle control mode. Instructs switching to the assist control mode.
- the manual input determination unit 410 has a configuration as shown in FIG. 7, and an LPF (low-pass filter) 411 for removing disturbance torque (noise) of the steering torque Th and the absolute value of the steering torque Tha output from the LPF 411.
- the limiter 414 that limits the upper and lower limit values of the output signal Ct so as not to input an excessive signal
- the integration calculation unit 415 that integrates the entire integral input value Cta from the limiter 414
- the switching determination unit 416 that compares the integrated output value Iout with a predetermined integration threshold Sth and outputs a steering torque determination signal TD.
- the integral calculation unit 415 may be a pure integral or a pseudo-integral composed of a first-order LPF.
- An LPF 411 that removes disturbance torque (noise) of the steering torque Th is provided in order to avoid turning around and becoming difficult to switch.
- the LPF 411 may be primary or secondary, and may be any filter that removes disturbance torque (noise) of IIR (Infinite Impulse Response) type or FIR (Finite Impulse Response) type and can be mounted. The effect of the LPF 411 will be described later with a specific example.
- the torque value comparison unit 413 compares the absolute value
- the integration calculation unit 415 The integration operation of the integration input value Cta is started and integration is continued.
- the integration calculation unit 415 receives the past value initialization signal from the torque value comparison unit 413.
- the integration value is initialized to 0 by Pi. That is, the torque value comparison unit 413 performs the following operation. Since the comparison is made using the absolute value
- the switching determination unit 416 performs the following operation.
- Equation 2 When Iout ⁇ Sth, the steering torque determination signal TD for satisfying the switching condition When Iout ⁇ Sth, the steering torque determination signal TD that does not satisfy the switching condition
- a steering torque determination signal TD from the manual input determination unit 410 is input to the gradual gain generation unit 430 together with the steering torque Th and the switching command SW, and the gradual gain generation unit 430 includes the speed command gradual change gain SG1 and the speed control gradual change.
- a gain SG2 is generated.
- the speed command gradual change gain SG1 is mainly used to realize smooth switching at the time of switching from assist control to steering angle control, and with respect to the steering angular speed command value ⁇ c output from the position control unit (210).
- the speed control gradual gain SG2 is an integral-related signal (for example, in the steering angular speed control unit (220)) in order to reduce the influence of accumulation of integral values in the steering angular speed control unit (220) at the time of switching. Is multiplied by the integral output value (Iout)) and used to realize smooth switching.
- the steering torque determination signal TD is input to the gradual change gain switching generation unit 420 together with the switching command SW, and the gradual change gain switching generation unit 420 generates the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2.
- the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are input to the switching unit 142.
- the steering angle control output gradual change gain SWG1 is gradually changed by being multiplied by the steering angle control command value (current command value) Imref output from the limiter 203 of the steering angle control unit 200, and switching operation between the heel assist control and the steering angle control. It is used to achieve smoothness and a sense of incongruity and safety for the driver.
- the assist control output gradual change gain SWG2 is multiplied by the assist control command value (current command value) Itref output from the assist control unit 141 to be gradually changed, thereby facilitating the switching operation between the steering angle control and the assist control. Used to realize steering intervention by the driver during automatic driving.
- a configuration example of the steering angle control unit 200, the switching unit 142, and the preprocessing unit 500 is shown in FIG. 8, and the preprocessing unit 500 uses the steering angle command value for automatic driving from the steering angle command value generation unit 132.
- a limiter 510 that limits upper and lower limit values to prevent an abnormal value due to a communication error or an excessive value from being input to the steering angle control unit 200 with respect to ⁇ ref, and a steering angle command value ⁇ ref1 from the limiter 510
- the steering angle command value ⁇ ref1 is included in the rate limiter 520 that performs rate limit processing, and the steering angle command value ⁇ ref2 after the rate limit.
- a handle vibration removing unit 530 for reducing a handle vibration frequency component.
- the rate limiter 520 also leads to an improvement in the safety to the driver, such as entanglement due to a sudden steering behavior.
- the rate limiter past value is initialized to the actual steering angle ⁇ r when switching from the assist control mode to the steering angle control mode.
- the target steering angle ⁇ t output from the steering wheel vibration removal unit 530 at the time of switching substantially coincides with the actual steering angle ⁇ r, so that the sudden change in the steering angle control current command value is suppressed, and as a result, the steering wheel suddenly changes. Variations can be prevented.
- the rate limiter 520 is configured as shown in FIG. 9, and the steering angle command value ⁇ ref1 is added to the subtraction unit 520-1, and the steering angle command value ⁇ t1, which is a subtraction result with the past value, is set as a change amount.
- the change amount ⁇ t2 is set by the unit 520-2.
- the change setting unit 520-2 sets the difference ⁇ t1 between the past value from the holding unit (Z ⁇ 1 ) 520-4 and the input ( ⁇ ref1), and the change ⁇ t2 between the addition unit 520-3 and the past value is set.
- the addition result is output as a new steering angle command value ⁇ ref2.
- the change setting unit 520-2 prevents the change from exceeding the set upper limit and lower limit, and its characteristic is to obtain a difference from the input (steering angle command value) ⁇ ref1 every calculation cycle T.
- the change amount setting unit 520-2 is outside the upper limit and lower limit ranges, the output ⁇ ref2 is changed in a stepwise manner as shown in FIG. Therefore, the output ⁇ ref2 is made to coincide with the steering angle command value ⁇ ref1.
- the change ⁇ t2 the difference ⁇ t1 is output and added to the past value.
- the output ⁇ ref2 and the input (steering angle command value) ⁇ ref1 coincide.
- the rapidly changing steering angle command value ⁇ ref2 can be changed smoothly, preventing a sudden current change and the driver's anxiety about automatic driving. It plays a function that reduces the feeling.
- the steering wheel vibration removal unit 530 following the rate limiter 520 reduces a vibration frequency component included in the steering torque Th by a low-pass filter (LPF), a notch filter, or phase delay compensation. From the steering wheel vibration removing unit 530, the target rudder angle ⁇ t preprocessed as described above is output.
- LPF low-pass filter
- the target rudder angle ⁇ t from the pre-processing unit 500 is added and inputted to the subtraction unit 210-1 in the position control unit 210 of the rudder angle control unit 200 whose detailed configuration is shown in FIG.
- the subtraction unit 210-1 receives the subtraction input of the actual steering angle ⁇ r, and the subtraction unit 210-1 obtains the target steering angle ⁇ t and the angle deviation ⁇ e of the actual steering angle ⁇ r, and the angle deviation ⁇ e is the proportional unit 210-2.
- the proportional control (gain Kpp) is performed, and the steering angular velocity command value ⁇ c is output from the position control unit 210.
- the steering angular velocity command value ⁇ c is input to the multiplication unit 201, and is gradually changed by the multiplication unit 201 with the speed command gradual change gain SG1, and the gradually changed steering angular velocity command value ⁇ ca has upper and lower limit values according to the speed command gradual change gain SG1.
- the limiter 202 to be limited.
- the limiter 202 has its positive and negative upper and lower limits limited according to the speed command gradual change gain SG1. That is, as the speed command gradual change gain SG1 is reduced, the limit value of the limiter 202 is also reduced.
- the limit value of the limiter 202 is also greatly limited. The operation of the limiter 202 will be described later with an example.
- the target rudder angular velocity ⁇ cb whose upper and lower limits are limited by the limiter 202 is input to the rudder angular velocity control unit 220 together with the actual rudder angular velocity ⁇ r and the speed control gradual change gain SG2. As shown in detail in FIG.
- the steering angular speed control unit 220 integrates the subtraction unit 221 that subtracts the actual steering angular speed ⁇ r from the target steering angular speed ⁇ cb, and the speed deviation Df that is the subtraction result of the subtraction unit 221 (Kvi / s )
- the proportional unit 225 to compensate the actual steering angular velocity ⁇ r by proportional processing (Kvp), and the proportional result of the proportional unit 225 from the steering angle control current value Ir1 that is the integration result of the integration unit 222.
- a subtracting unit 223 for subtracting the steering angle control current value Ir2 and a speed control current value Imref0 as a subtraction result of the subtracting unit 223 are gradually changed by the speed control gradually changing gain SG2, and a speed control current value Imref1 is output.
- the speed control current value Imref1 from the multiplication unit 224 is input to the addition unit 204, added to the vibration suppression signal (current value) Thd subjected to vibration suppression processing from the steering wheel vibration suppression unit 440, and the steering angle control command that is the addition result.
- the upper and lower limit values of the value Imref2 are limited by the limiter 203 for preventing excessive output, and the steering angle control command value Imref is output.
- the handle damping unit 440 is provided for damping the steering torque Th based on the column shaft saddle torsion bar and further improving the damping effect of the handle vibration during automatic steering.
- the structure of the steering wheel damping unit 440 is, for example, FIG. 13 and includes a gain unit 441 that gains the steering torque Th (Kv) and a phase compensation unit 442 that compensates the phase of the steering torque Kv ⁇ Th from the gain unit 441. ing.
- the phase compensation unit 442 is configured by, for example, a primary filter, and outputs a vibration suppression signal Thd in a direction to eliminate torsion of the torsion bar. ⁇
- any filter can be used as long as it has a handle damping effect.
- the switching unit 142 is configured to multiply the steering angle control command value Imref by the steering angle control output gradual change gain SWG1, and to multiply the assist control command value Itref by the assist control output gradual change gain SWG2.
- step S1 it is determined whether or not the switching command SW is input from the switching command unit 131 (step S1). If the switching command SW is not input, the steering wheel is steered (left and right) by the driver in the steering angle control mode. Then, the steering torque Th is input to the manual input determination unit 410 (step S2), and the manual input determination unit 410 determines the above-described Equation 2 and the manual input as described later (step S10). If the torque determination signal TD for switching the control mode is not output (step S20), the switching determination / gradual change gain generation unit 400 uses the speed command gradual change gain SG1, the speed control gradual change gain SG2, and the steering angle control output gradual change.
- the gain SWG1 and the assist control output gradual change gain SWG2 are generated to change to the value of the steering angle control mode (step S21), and the speed command gradual change gain SG1 and Speed control gradual change gain SG2 is input to the steering angle control unit 200 (step S22), and the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 is inputted to the switching unit 142 (step S25). Thereby, the steering angle control by the steering angle control part 200 is continued.
- the switching determination / gradual change gain generation unit 400 uses the speed command gradually.
- the variable gain SG1, the speed control gradual change gain SG2, the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are generated and transitioned to the value of the assist control mode (step S24), and the speed command gradual change gain SG1 is generated.
- the speed control gradual change gain SG2 is input to the steering angle control unit 200 (step S22), and the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are input to the switching unit 142 (step S25). Thereby, assist control by the assist control unit 141 is performed.
- each gradually changing gain used in the present invention each gradually changing gain after detection of manual input by the driver during the automatic driving state (a state in which both the steering angle control and the assist control are present).
- An embodiment for shifting to the assist control mode will be described with reference to FIG. 15A shows the gradual change operation of the steering angle control output gradual change gain SWG1, the speed command gradual change gain SG1, and the speed control gradual change gain SG2.
- FIG. 15B shows the assist control output gradual change gain SWG2. The gradual change operation is shown.
- Manual input determination is completed at time t 10
- shows a state of transition from the steering angle control mode to the assist control mode is a state in which the switches are shifted to time t 11 is finished to assist control mode.
- the gradual gains SG1, SG2 and SWG1 are gradually decreased from 100% and transitioned to 0% as shown in FIG. 15A after manual input determination. In this embodiment, it is linearly changed. However, in order to make the switching operation smooth, the transition may be made with an S-shaped curve such as a clothoid curve, or a primary LPF (cutoff frequency 2 [Hz]). It is good also as each gradually changing gain the value which passed.
- the gradual change gains SG1, SG2, and SWG1 do not need to be interlocked with the same characteristic, and may include independent characteristics including the assist control output gradual change gain SWG2.
- the assist control output gradual change gain SWG2 does not always have to be 0% in the automatic operation state, and may be a value larger than 0%, for example, 50% as shown in FIG.
- the assist control output gradual change gain SWG2 as an adjustment factor, for example, 50%, it becomes possible to suppress a feeling of being caught during steering intervention in the steering angle control mode. After manual input determination, the transition is from 50% to 100%.
- step S10 in FIG. 14 an example of the operation of the manual input determination unit 410 shown in FIG. 7 (step S10 in FIG. 14) will be described with reference to the flowchart in FIG.
- step S10-1 When steering torque Th is input (step S10-1), disturbance torque (noise) is removed by LPF 411 (step S10-2), and absolute value
- a torque threshold value Tth is input in advance to the torque value comparison unit 413, and the torque value comparison unit 413 determines whether or not the absolute value
- the output signal Ct is set to 0 so as not to integrate, and the past value initialization signal Pi is output to initialize the integration calculation unit 415.
- the integral output value Iout from the integral calculation unit 415 is input to the switching determination unit 416, and the switching determination unit 416 determines whether or not the integral output value Iout is greater than or equal to the integration threshold value Sth (step S10-7).
- the switching condition of Equation 2 is satisfied (step S10-8), and the gradually changing gains SG1, SG2, SWG1, SWG2 are updated by the steering torque determination signal TD ( In step S10-9, the steering angle control mode is switched to the assist control mode (step S10-10).
- the integral output value Iout is smaller than the integral threshold value Sth, the switching condition of Equation 2 is not satisfied and the control mode is not switched (step S10-11).
- FIG. 17 shows the context of the integration operation of an example of a temporal change with respect to the torque threshold value Tth of the disturbance torque steering torque Th removed (noise) (Tha) in LPF411, from the start to the time point t 1 is the steering torque Th Is smaller than the torque threshold value Tth, so no integration is performed.
- the steering torque Th is the integration of the entire input signal since torque threshold value Tth or higher is performed, switching the whole of the integral value is less than the integral threshold value Sth conditions and not satisfied It has become.
- the integrated output value Iout corresponds to the area of the shaded portion in FIG. 17 and is the total of the steering torque Th (absolute value).
- Integrated value becomes a predetermined value (integration threshold Sth) above at time t 4, it shows how the switching condition is satisfied. That is, although the area of the hatched portion in FIG. 17 has a integral value equivalent, the integral value at time t 2 is switching condition smaller than the integral threshold value Sth is not satisfied, the integrated value at time t 4 the integral threshold Sth or In this example, the switching condition is satisfied.
- the steering angle command value ⁇ ref is preprocessed by the preprocessing unit 500, and the preprocessed target steering angle ⁇ t is input to the steering angle control unit 200, but the preprocessing unit 500 is input to the steering angle control unit 200.
- a configuration including this may be used.
- the target rudder angle ⁇ t, actual rudder angle ⁇ r, actual rudder angular velocity ⁇ r, steering torque Th, speed command gradual change gain SG1, and speed control gradual change gain SG2 are input (step S30), and the position control unit 210 controls the position ( Step S31). That is, the angle deviation ⁇ e between the target rudder angle ⁇ t and the actual rudder angle ⁇ r is obtained by the subtracting unit 211, and the angle deviation ⁇ e is proportionally processed by the proportional unit 212.
- the steering angular speed command value ⁇ c whose position is controlled by the position control unit 210 is gradually changed by the speed command gradually changing gain SG1 in the multiplication unit 201 (step S32), and the gradually changed steering angular speed command value ⁇ ca is converted by the limiter 202 in the speed command.
- Limit processing is performed according to the gradual change gain SG1 (step S33).
- the target rudder angular velocity ⁇ cb subjected to the limit processing is input to the subtracting unit 221 in the rudder angular velocity control unit 220, and a speed deviation Df from the actual rudder angular velocity ⁇ r is calculated (step S34).
- the speed deviation Df is input to the integration unit 222 and integrated (step S35), and the actual steering angular speed ⁇ r is proportionally processed by the proportional unit 225 (step S36), and proportionally processed from the integrated steering angle control current value Ir1.
- the steering angle control current value Ir2 is subtracted by the subtraction unit 223 (step S37), and the speed control current value Imref0 obtained by subtraction is input to the multiplication unit 224 and gradually changed by the speed control gradual change gain SG2 (step S37). S40).
- the gradually changed speed control current value Imref1 is input to the adding unit 204.
- the steering torque Th is input to the steering wheel damping unit 440 and subjected to vibration damping processing (step S41), and the vibration damping signal Thd subjected to vibration damping processing is input to the adding unit 204 and added to the speed control current value Imref1. (Step S42).
- the upper and lower limit values of the added steering angle control command value Imref2 are limited by the limiter 203 (step S43), and the steering angle control command value Imref is output (step S44).
- the input order of the target rudder angle ⁇ t, actual rudder angle ⁇ r, actual rudder angular speed ⁇ r, steering torque Th, speed command gradual change gain SG1, and speed control gradual change gain SG2 can be changed as appropriate.
- the handle vibration removing unit 530 is provided in the pre-processing unit 500.
- the pre-processing unit 500A in which the handle vibration removing unit 530 is deleted is used, and position control as shown in FIG.
- the configuration of the unit 200A may be used. That is, the pre-processing unit 500A includes a limiter 410 and a rate limiter 420, and the position control unit 200A includes a handle vibration removal unit 211, a subtraction unit 212, a feed forward (FF) filter 213, and a gain (Kpp) unit 214. And an adder 215.
- the target rudder angle ⁇ t from the preprocessing unit 500A is input to the handle vibration removal unit 211 and the FF filter 213 in the position control unit 210A.
- a frequency component (about 10 Hz) that excites vibration due to the spring property of the torsion bar and the inertial moment of the steering wheel is generated in the rudder angle command value ⁇ ref.
- the steering wheel vibration removal unit 211 Is provided.
- the handle vibration removal unit 211 reduces the vibration frequency component by LPF, notch filter, or phase delay compensation.
- the steering angle signal ⁇ t1 from the steering wheel vibration removing unit 211 is added and input to the subtracting unit 212.
- the FF filter 213 is used to calculate a steering angular velocity command value that improves the followability of the steering angle control, but may be set by combining a pseudo differential calculation and a gain unit in series.
- the LPF is arranged after the differential operation in order to remove noise by the differential operation.
- a backward difference or HPF high-pass filter
- a filter for reducing the frequency component (around 10 Hz) of the middle vibration included in the target rudder angle ⁇ t may be included in the same manner as the steering wheel vibration removing unit 211.
- a first-order LPF cut-off frequency 2 Hz
- a notch filter center frequency 10 Hz
- a phase lag compensation filter and the like are connected in series.
- the steering angle command value ⁇ ref is input (step S30-1), the preprocessing unit 500A is preprocessed by the limiter 510 and the rate limiter 520 (step S30-2), and the preprocessed target steering angle ⁇ t is output. (Step S30-3).
- the target rudder angle ⁇ t is input to the handle vibration removal unit 211 in the position control unit 210A, the handle vibration frequency component of the target rudder angle ⁇ t is removed by the handle vibration removal unit 211 (step S31-1), and the subtraction unit 212 handles the handle.
- An angle deviation ⁇ e between the steering angle signal ⁇ t1 from the vibration removing unit 211 and the actual steering angle ⁇ t is obtained (step S31-2), and the angle deviation ⁇ e is proportionally processed (gain Kpp) by the proportional unit 214 (step S31 ⁇ ). 3).
- the proportionally processed angle deviation ⁇ eg is input to the adder 215.
- the target rudder angle ⁇ t is input to the FF filter 213 and filtered (step S31-4), and the filtered angle signal ⁇ t2 is input to the adder 215 and added to the angle deviation ⁇ eg (step S31-5).
- the added steering angular speed command value ⁇ c is output (step S31-6).
- step S100 assist control by the assist control unit 141 is performed (step S100), and the motor 150 is driven by the current control / drive unit 143 using the assist control command value Itref (step S101).
- step S101 assist control command value
- step S102 The switching command SW is input to the switching determination / gradual change gain generation unit 400 together with the steering torque Th.
- the steering angle command value ⁇ ref is input from the steering angle command value generation unit 132 to the pre-processing unit 500 (or 500A) (step S103).
- the target rudder angle ⁇ t preprocessed by the pre-processing unit 500 is input to the rudder angle control unit 200 (step S104), and the actual rudder angle ⁇ r from the rudder angle sensor 14 passes through the vehicle ECU 130 and the rudder angle control unit 200.
- Step S105 the actual steering angular velocity ⁇ r from the motor angular velocity calculation unit 144 is input to the steering angle control unit 200 (step S106).
- the steering torque Th is input to the switching determination / gradual change gain generation unit 400 (step S107), and the switching determination / gradual change gain generation unit 400 uses the above-described method to perform the speed command gradual change gain SG1 and the speed control gradual change gain SG2. Then, the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are generated (step S108), the speed command gradual change gain SG1 and the speed control gradual change gain SG2 are input to the steering angle control unit 200, and the steering angle The control output gradual change gain SWG 1 and the assist control output gradual change gain SWG 2 are input to the switching unit 142.
- the steering angle control unit 200 generates the steering angle control command value Imref by the above-described arithmetic processing (step S110), and the steering angle control command value Imref is input to the switching unit 142.
- the switching unit 142 is input with the assist control command value Itref from the assist control unit 141 and the steering angle control command value Imref from the steering angle control unit 200, as well as the steering angle control output gradually changing gain SWG1 and the assist control output.
- Gradual change gain SWG2 is input, and is gradually changed according to the above-described relationship to switch from assist control to steering angle control (step S111). Then, the control is switched to the steering angle control, the steering of the steering angle control is performed (step S112), the above-described manual input determination is performed (step S113), and the above operation is repeated until the integral value reaches the integration threshold value Sth. (Step S114). When the integrated value reaches the integration threshold value Sth, the steering angle control is switched to the assist control by the gradual change by the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 (step S120).
- a target steering angle ⁇ t, an actual steering angle ⁇ r, and an actual steering angular speed ⁇ r are input (step S200), and then a speed command gradual change gain SG1, a speed control gradual change gain SG2, a steering angle control output gradual change gain SWG1, and an assist control output.
- the gradually changing gain SWG2 is input (step S201). The order of these inputs can be changed as appropriate.
- the position control unit 210 is position-controlled so that the actual steering angle ⁇ r follows the target steering angle ⁇ t, and the steering angle speed command value ⁇ c is output from the position control unit 210 (step S202).
- the steering angular velocity command value ⁇ c is input to the multiplication unit 201, and the steering angular velocity command value ⁇ ca from the multiplication unit 201 is input to the limiter 202.
- the speed command gradual change gain SG1 is changed linearly with respect to the time series as shown in FIG.
- the addition value may be a constant value.
- the speed command gradual change gain SG1 100% or more, 100% (Steps S204 and S205). It is determined whether or not the speed command gradual change gain SG1 is greater than or equal to a threshold value (step S206). If the speed command gradual change gain SG1 is greater than or equal to the threshold value, the limiter limit value is added from the previous value (step S207). (When the speed command gradual change gain SG1 is changed linearly with respect to time series as shown in FIGS. 24 and 25 to be described later, the addition value may be a constant value.) Is the limiter limit value equal to or greater than the limit value 2? It is determined whether or not (step S208). If the limiter limit value is greater than or equal to the limit value 2, the limiter limit value is set to the limit value 2 (step S209).
- the multiplier 201 gradually changes with the speed command gradually changing gain SG1 (step S210).
- the steering angular velocity command value ⁇ ca after the gradual change from the multiplication unit 201 is input to the limiter 202 and the upper and lower limit values are limited (step S211).
- the target rudder angular velocity ⁇ cb from the limiter 202 is input to the rudder angular velocity control unit 220 together with the actual rudder angular velocity ⁇ r, and speed control for causing the actual rudder angular velocity ⁇ r to follow the target rudder angular velocity ⁇ cb is performed.
- the steering angular speed control unit 220 calculates a speed deviation Df, calculates the integral-compensated steering angle control current value Ir1 and the proportionally compensated steering angle control current value Ir2 as described above, and performs speed control as a deviation thereof.
- the current value Imref0 is calculated (step S212).
- the speed control current value Imref0 is gradually changed by the multiplication unit 224 by the speed control gradual change gain SG2, the gradually changed speed control current value Imref1 is output, and the speed control current value Imref1 is input to the addition unit 204 (step S213). ).
- a vibration suppression process based on the steering torque Th is performed, and the vibration suppression signal Thd after the vibration suppression process is added to the speed control current value Imref1 by the adding unit 204, and the added steering angle control command value Imref2 is the limiter 203.
- the limit process is performed, and the steering angle control command value Imref is output (step S214).
- the steering angle control command value Imref is gradually changed by the steering angle control output gradually changing gain SWG1 in the multiplying unit 142-1 (step S215), and the gradually changed steering angle control command value Imrefg is input to the adding unit 142-3. .
- the variable gain SWG2 is 0% or less, the variable gain SWG2 is limited to 0% (steps S221 and S222).
- the multiplier 142-2 While calculating the assist control command value Itref, the multiplier 142-2 gradually changes the assist control output value Itrefg gain SWG2, and outputs the assist control command value Itrefg (step S223).
- the gradually changed assist control command value Itrefg is input to the adder 142-3 and added to the steering angle control command value Imrefg to calculate the motor current command value Iref (step S224).
- the motor is driven by the motor current command value Iref.
- the previous value of the steering angle control output gradual change gain SWG1 is updated to the steering angle control output gradual change gain SWG1
- the previous value of the assist control output gradual change gain SWG2 is updated to the assist control output gradual change gain SWG2, and the speed is increased.
- the previous value of the command gradual change gain SG1 is updated to the speed command gradual change gain SG1
- the previous value of the speed control gradual change gain SG2 is updated to the speed command gradual change gain SG2
- the previous value of the limiter limit value of the limiter 202 is further updated.
- the limiter limit value is updated (step S225).
- the previous value is updated for the speed command gradual change gain SG1 and the speed control gradual change gain SG2.
- FIG. 24 and 25 are time charts showing the relationship among the target steering angular velocity ⁇ cb, the steering angle control output gradual change gain SWG1, the assist control output gradual change gain SWG2 and the limit value 1 and limit value 2 of the limiter 202 after the limiter 202.
- FIG. is there.
- the assist control output gradual change gain SWG2 in the steering angle control state is described as 50%, but in FIG. 24 and FIG.
- a state is shown in which the shift from the assist control to the steering angle control is performed at time t0 and the steering angle control is completely performed at time t3.
- the limit value of the limiter 202 is from the limit value 1 to the limit value 2 (> limit value 1) between the time point t2 (set by the threshold) slightly before the time point t3 when the steering angle control is completely performed and the time point t4 after the time point t3. ) Gradually change.
- the example of FIG. 25 also shows a state where the assist control is shifted to the steering angle control at time t10 and the steering angle control is completely performed at time t12.
- the limit value of the limiter 202 is changed from the limit value 1 to the limit value 2 between the time point 12 when the steering angle control is completely performed and the time point t13 thereafter.
- the control output gradual change gain SWG2 is configured so that the total value of the ratios increases and decreases in a relationship of 1.0 (100%) in principle and in an opposite relationship.
- the increase / decrease waveform (characteristic) is arbitrary, and may be linear or non-linear.
- the speed command gradual change gain SG1 is multiplied to the steering angular speed command value ⁇ c output from the position control unit 210.
- This gradual change gain SG1 is synchronized with the steering angle control output gradual change gain SWG1 multiplied by the steering angle control command value Imref (not necessarily completely synchronized).
- a limiter 202 having a variable upper and lower limit is provided for the steering angular speed command value ⁇ ca after multiplication by the speed command gradual change gain SG1.
- the limiter 202 can sequentially switch the limit value of the steering angular velocity command value ⁇ ca, and this limit value is fixed to a small value when the gradual change gain SG1 is less than the set threshold value, and gradually increased above the threshold value.
- the value ⁇ ca is limited and is input to the steering angular velocity control unit 220 as the target steering angular velocity ⁇ cb. Further, the signal in the speed control unit 220 is multiplied by a speed control gradually changing gain SG2 (which may be synchronized with SG1). As a result, excessive accumulation of the integral value in the rudder angular velocity control unit 220 is suppressed, and the current command value as the rudder angle control output that causes discomfort to the driver is reduced.
- the steering angle speed command value ⁇ ca is not limited by the speed command gradual change gain SG1 and the upper / lower limit variable limiter 202, and the signal in the steering angular speed control unit 220 is not limited by the speed control gradual change gain SG2. Shift to normal steering angle control.
- the speed control gradual change gain SG2 and the speed command gradual change gain SG1 are not displayed in FIGS. 24 and 25, and are made to coincide with the steering angle control output gradual change gain SWG1.
- the value of the past value Z ⁇ 1 of the rate limiter of the steering angle command value is overwritten with the detected actual steering angle.
- the target steering angle ⁇ t after the step of the steering wheel vibration removing unit 430 and the actual steering angle ⁇ r substantially coincide with each other at the time of switching, thereby suppressing the generation of the steering angle control current command value and consequently preventing the steering wheel from changing suddenly. To do.
- an LPF 411 (a cutoff frequency of 2 Hz with a primary filter) is used as an input unit of the manual input determination unit 410, and an absolute value unit 412 for obtaining an absolute value
- is compared with the torque threshold value Tth, and the integral value is further compared with the integral threshold value Sth.
- FIG. 26 schematically shows a problem in the case where manual input is determined only by an absolute value and a torque threshold as shown in Patent Document 3, and is transient during traveling on a rough road or the like. Due to the influence of a large road disturbance, a disturbance torque Td as shown in FIG. 26A is generated around the column axis. Due to the influence of the road surface disturbance (disturbance torque), the disturbance component is added to the steering torque (torsion bar torque), and as shown in FIG. There is a problem that becomes a judgment. That is, it is a function that is easily affected by road surface disturbances and is easily misjudged.
- the present invention when manual input is determined only by the torque threshold value and the integral threshold value as shown in Patent Document 4 without using an absolute value, it is positive or negative with respect to the steering torque Th as shown in FIG. It is necessary to set a torque threshold value, and it is necessary to set a positive / negative integral threshold value with respect to the integral output value Iout as shown in FIG.
- of the steering torque Th is obtained, the absolute value
- the present invention is advantageous in that it is less susceptible to road surface disturbances and is less prone to erroneous determination.
- FIG. 29 shows that the present invention is superior to the apparatus disclosed in Patent Document 4, and in the present invention, one torque threshold value Tth is set for the steering torque Th as shown in FIG. 29 (A).
- the branching process can be simplified as compared with the case where the absolute value is not used.
- the integral calculation unit 415 is an absolute value, even if the steering torque Th is negative (thin line), the integral output value Iout is always 0 or more as shown in FIG.
- One integration threshold value Sth may be set for the output value Iout.
- the branch process can be simplified as compared with the case where the absolute value is not used. Since the absolute value conversion according to the present invention is performed before the torque value comparison unit 413, only one torque threshold value Tth and one integration threshold value Sth are required.
- FIG. 30 of the simulation when the disturbance torque Td (column shaft torque conversion) is input to the steering torque Th when the steering angle command value is generated during the steering angle control, the torsion bar detected torque (steering Torque Th) is indicated by a thick line in FIG. 31 (simulation), and the steering torque Tha that has passed through the LPF 411 is attenuated in amplitude as shown by a thin line in FIG.
- FIG. 31 also shows a torque threshold Tth used as a condition for executing the integration (integration) calculation.
- FIG. 29 is a simulation result of integrating signals corresponding to the presence / absence of the LPF 411 in FIG. 31 by the integration calculation unit 415 on the same time axis.
- the integration calculation a value obtained by multiplying the calculation cycle 0.001 [s] and the steering torque Th (absolute value) is added to the previous value, and the integration threshold Sth is set to 3.5 [Nm].
- the steering torque Th fluctuates due to the disturbance torque Td, and when the absolute value of the steering torque Th (Tha) falls below the torque threshold value Tth, the integrated value is reset to 0 and a delay occurs until the integrated threshold value Sth is reached. ing.
- the LPF 411 inserted reduces the influence of the disturbance torque Td, reaches the integral threshold value Sth earlier, and speeds up manual input determination.
- the integral input value Iout of the abnormal excessive value is integrated and the integrated output value Iout exceeds the integration threshold value Sth.
- An erroneous determination may occur. Therefore, in the present invention, by providing the limiter 414 before the integral input value Cta, even if the absolute value of the steering torque Th becomes an abnormal excessive value, the integral output value Iout does not exceed the integral threshold value Sth, and the manually input value The misjudgment is prevented.
- the integral value continues to be reset to 0, so that the integral output value Iout Is 0.
- the integral output value Iout is smaller than the integral threshold value Sth, it is determined that there is no manual input.
- the torque threshold value Tth is exceeded and integration is performed for the abnormally excessive value. Perform the operation. For this reason, as shown in FIG. 33C, the integrated output value Iout exceeds the integration threshold value Sth, and it is determined that the manual input is “present”.
- the target is speed control in the above, it is also effective for a control system having a configuration in which input such as a required steering angle is accumulated and used for output such as a current command value, for position control and speed control. If the function is incorporated, other configurations can be changed as appropriate. Furthermore, the actual steering angular speed may be obtained from the motor speed and the reduction ratio, or may be obtained from a steering wheel steering angle sensor.
- FIG. 12 FIG. 15, FIG. 17, FIG. 24 to FIG. 29, FIG. 33, and FIG. 34 are all schematic views and are diagrams for easy understanding.
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Abstract
[Problem] To provide an electric power steering apparatus that performs gradual switching between a steering angle control mode and an assist control mode and that, by using integration and an absolute value, performs shifting to the assist control mode through determination of a manual input even in the steering angle control mode. [Solution] This electric power steering apparatus is provided with a switching-determination/gradual-change gain generation unit that generates a speed command gradual-change gain, a speed control gradual gain, a steering angle control output gradual-change gain, and an assist control output gradual-change gain. A steering angle control unit: is provided with a position control unit that outputs a steering angle speed command value from angular deviation, a gradual-change limitation unit that gradually changes and limits the steering angle speed command value in accordance with the speed command gradual-change gain, a steering angle speed control unit that processes a target steering angle speed on the basis of the real steering angle speed and a speed gradual-change gain, a gradual-change output unit 1 that gradually changes a speed control current value and outputs a steering angle control command value 2, and a gradual-change output unit 2 that gradually changes and outputs an assist control command value 1; and generates a current command value on the basis of the steering angle control command value 2 and the assist control command value 2. The switching-determination/gradual-change gain generation unit has a manual input determination unit.
Description
本発明は、車両の操舵制御において舵角制御モード(駐車支援等の自動操舵制御モード)及びアシスト制御モード(手動操舵制御モード)の切換機能を有し、モータ電流指令値によりモータを駆動し、車両の操舵系にアシスト力を付与するようにした電動パワーステアリング装置に関し、特に舵角制御モードからアシスト制御モードへの切換及びアシスト制御モードから舵角制御モードへの切換を徐変ゲインで徐変すると共に、舵角制御モード中においても手入力の判定を誤判定なく行って、円滑かつ確実にアシスト制御モードに移行するようにし、モータ電流指令値に対して意図しないハンドルの変動を抑制し、運転者への違和感を低減する高機能な電動パワーステアリング装置に関する。
The present invention has a switching function between a steering angle control mode (automatic steering control mode such as parking assistance) and an assist control mode (manual steering control mode) in steering control of a vehicle, and drives a motor by a motor current command value. With regard to an electric power steering apparatus that applies an assist force to a vehicle steering system, in particular, a gradual change with a gradual gain is used to switch from the steering angle control mode to the assist control mode and from the assist control mode to the steering angle control mode. In addition, even during the rudder angle control mode, manual input determination is performed without erroneous determination, so that the shift to the assist control mode smoothly and reliably is performed, and unintended steering wheel fluctuations with respect to the motor current command value are suppressed. The present invention relates to a high-performance electric power steering device that reduces a sense of incongruity to a driver.
車両のステアリング機構にモータの回転力で操舵補助力(アシスト力)を付与する電動パワーステアリング装置(EPS)は、モータの駆動力を減速機を介してギア又はベルト等の伝達機構により、ステアリングシャフト或いはラック軸に操舵補助力を付与するようになっている。かかる従来の電動パワーステアリング装置は、操舵補助力のトルクを正確に発生させるため、モータ電流のフィードバック制御を行っている。フィードバック制御は、操舵補助指令値(電流指令値)とモータ電流検出値との差が小さくなるようにモータ印加電圧を調整するものであり、モータ印加電圧の調整は、一般的にPWM(パルス幅変調)制御のデューティの調整で行っている。
An electric power steering device (EPS) that applies a steering assist force (assist force) to a steering mechanism of a vehicle by a rotational force of a motor is provided with a steering shaft by a transmission mechanism such as a gear or a belt via a speed reducer. Alternatively, a steering assist force is applied to the rack shaft. Such a conventional electric power steering apparatus performs feedback control of the motor current in order to accurately generate the torque of the steering assist force. In feedback control, the motor applied voltage is adjusted so that the difference between the steering assist command value (current command value) and the motor current detection value is small. This is done by adjusting the duty of modulation) control.
電動パワーステアリング装置の一般的な構成を図1に示して説明すると、ハンドル(ステアリングホイール)1のコラム軸(ステアリングシャフト、ハンドル軸)2は減速ギア3、ユニバーサルジョイント4a及び4b、ピニオンラック機構5、タイロッド6a,6bを経て、更にハブユニット7a,7bを介して操向車輪8L,8Rに連結されている。また、コラム軸2には、ハンドル1の舵角θrを検出する舵角センサ14及び操舵トルクThを検出するトルクセンサ10が設けられており、ハンドル1の操舵力を補助するモータ20が減速ギア3を介してコラム軸2に連結されている。電動パワーステアリング装置を制御するコントロールユニット(ECU)30には、バッテリ13から電力が供給されると共に、イグニションキー11を経てイグニションキー信号IGが入力される。コントロールユニット30は、トルクセンサ10で検出された操舵トルクThと車速センサ12で検出された車速Vsとに基づいてアシスト制御の電流指令値の演算を行い、電流指令値に補償等を施した電圧制御指令値Vrefによってモータ20に供給する電流を制御する。なお、舵角センサ14からは舵角θrが検出されるが、モータ20に連結されたレゾルバ等の回転センサから得ることもできる。
The general configuration of the electric power steering apparatus will be described with reference to FIG. 1. A column shaft (steering shaft, handle shaft) 2 of a handle (steering wheel) 1 is a reduction gear 3, universal joints 4 a and 4 b, and a pinion rack mechanism 5. The tie rods 6a and 6b are connected to the steering wheels 8L and 8R via the hub units 7a and 7b. Further, the column shaft 2 is provided with a steering angle sensor 14 for detecting the steering angle θr of the handle 1 and a torque sensor 10 for detecting the steering torque Th, and a motor 20 for assisting the steering force of the handle 1 is a reduction gear. 3 is connected to the column shaft 2 through 3. The control unit (ECU) 30 that controls the electric power steering device is supplied with electric power from the battery 13 and also receives an ignition key signal IG via the ignition key 11. The control unit 30 calculates a current command value for assist control based on the steering torque Th detected by the torque sensor 10 and the vehicle speed Vs detected by the vehicle speed sensor 12, and a voltage obtained by compensating the current command value. The current supplied to the motor 20 is controlled by the control command value Vref. Although the steering angle θr is detected from the steering angle sensor 14, it can also be obtained from a rotation sensor such as a resolver connected to the motor 20.
コントロールユニット30には、車両の各種情報を授受するCAN(Controller Area Network)40が接続されており、車速VsはCAN40から受信することも可能である。また、コントロールユニット30には、CAN40以外の通信、アナログ/ディジタル信号、電波等を授受する非CAN41も接続可能である。
The control unit 30 is connected to a CAN (Controller Area Network) 40 that exchanges various vehicle information, and the vehicle speed Vs can be received from the CAN 40. The control unit 30 can be connected to a non-CAN 41 that exchanges communications, analog / digital signals, radio waves, and the like other than the CAN 40.
コントロールユニット30は主としてCPU(Central Processing Unit)(MPU(Micro Processor Unit)やMCU(Micro Controller Unit)も含む)で構成されるが、そのCPU内部においてプログラムで実行される一般的な機能を示すと図2のようになる。
The control unit 30 is mainly composed of a CPU (Central Processing Unit) (including MPU (Micro Processor Unit) and MCU (Micro Controller Unit)), but it shows general functions executed by programs inside the CPU. As shown in FIG.
図2を参照してコントロールユニット30の機能及び動作を説明すると、トルクセンサ10で検出された操舵トルクTh及び車速センサ12で検出された(若しくはCANからの)車速Vsは、電流指令値Iref1を演算する電流指令値演算部31に入力される。電流指令値演算部31は、入力された操舵トルクTh及び車速Vsに基づいてアシストマップ等を用いて、モータ20に供給する電流の制御目標値である電流指令値Iref1を演算する。電流指令値Iref1は加算部32Aを経て電流制限部33に入力され、過熱保護条件で最大電流を制限された電流指令値Iref3が減算部32Bに入力され、フィードバックされているモータ電流値Imとの偏差Iref4(=Iref3-Im)が演算され、その偏差Iref4が操舵動作の特性改善のためのPI制御部35に入力される。PI制御部35で特性改善された電圧制御指令値VrefがPWM制御部36に入力され、更に駆動部としてのインバータ37を介してモータ20がPWM駆動される。モータ20の電流値Imはモータ電流検出器38で検出され、減算部32Bにフィードバックされる。
The function and operation of the control unit 30 will be described with reference to FIG. 2. The steering torque Th detected by the torque sensor 10 and the vehicle speed Vs detected by the vehicle speed sensor 12 (or from the CAN) are expressed as a current command value Iref1. The current command value calculation unit 31 to be calculated is input. The current command value calculation unit 31 calculates a current command value Iref1, which is a control target value of the current supplied to the motor 20, using an assist map or the like based on the input steering torque Th and vehicle speed Vs. The current command value Iref1 is input to the current limiting unit 33 through the adding unit 32A, and the current command value Iref3 whose maximum current is limited by the overheat protection condition is input to the subtracting unit 32B, and the motor current value Im being fed back The deviation Iref4 (= Iref3-Im) is calculated, and the deviation Iref4 is input to the PI control unit 35 for improving the characteristics of the steering operation. The voltage control command value Vref whose characteristics are improved by the PI control unit 35 is input to the PWM control unit 36, and the motor 20 is PWM driven via an inverter 37 as a drive unit. The current value Im of the motor 20 is detected by the motor current detector 38 and fed back to the subtraction unit 32B.
また、モータ20にはレゾルバ等の回転センサ21が接続されており、実舵角θsが検出される。加算部32Aには補償部34からの補償信号CMが加算されており、補償信号CMの加算によってシステム系の補償を行い、収れん性や慣性特性等を改善するようになっている。補償部34は、セルフアライニングトルク(SAT)343と慣性342を加算部344で加算し、その加算結果に更に収れん性341を加算部345で加算し、加算部345の加算結果を補償信号CMとしている。
Further, a rotation sensor 21 such as a resolver is connected to the motor 20, and the actual steering angle θs is detected. The adder 32A is added with the compensation signal CM from the compensator 34, and the compensation of the system system is performed by adding the compensation signal CM so as to improve the convergence and inertia characteristics. The compensator 34 adds the self-aligning torque (SAT) 343 and the inertia 342 by the adder 344, further adds the convergence 341 to the addition result by the adder 345, and the addition result of the adder 345 is the compensation signal CM. It is said.
このような電動パワーステアリング装置において、近年舵角制御モード(駐車支援等)及びアシスト制御モードを有し、これら制御モードの切換機能を有する車両が出現して来ており、自動操舵を実現する場合、舵角制御とアシスト制御を独立して保有し、これらの出力を切り換える構成が一般的である。舵角制御には、応答性や外乱抑圧性で優れた性能を持つ位置速度制御が用いられており、位置制御はP(比例)制御、速度制御はPI(比例積分)制御等で構成される。
In such an electric power steering apparatus, in recent years, vehicles having a steering angle control mode (parking support, etc.) and an assist control mode and having a switching function of these control modes have appeared, and automatic steering is realized. In general, the steering angle control and the assist control are independently held and these outputs are switched. For steering angle control, position / speed control with excellent performance in response and disturbance suppression is used. Position control is composed of P (proportional) control, speed control is composed of PI (proportional integral) control, etc. .
舵角制御モード及びアシスト制御モードの制御機能を具備し、操舵制御モードを切り換える機能を有する一般的な電動パワーステアリング装置を図3について説明すると、モータ150にはモータ回転角θsを検出するためのレゾルバ等の回転センサ151が接続されており、モータ150は車両側ECU130及びEPS側ECU140を介して駆動制御される。車両側ECU130は、運転者の意思を示すボタン、スイッチ等に基づいて、舵角制御モード又はアシスト制御モードの切換指令SWを出力する切換指令部131と、カメラ(画像)やレーザレーダなどの信号に基づいて目標舵角θtとなる舵角指令値θrefを生成する舵角指令値生成部132とを具備している。また、コラム軸(ステアリングシャフト、ハンドル軸)に設けられた舵角センサ14で検出された実舵角θrは、ECU130を経てEPS側ECU140内の舵角制御部200に入力される。
A general electric power steering apparatus having a control function of a steering angle control mode and an assist control mode and having a function of switching the steering control mode will be described with reference to FIG. 3. A motor 150 detects a motor rotation angle θs. A rotation sensor 151 such as a resolver is connected, and the motor 150 is driven and controlled via the vehicle side ECU 130 and the EPS side ECU 140. The vehicle-side ECU 130 is configured to output a switching command unit 131 that outputs a switching command SW for the steering angle control mode or the assist control mode based on a button, a switch, or the like indicating the driver's intention, and a signal such as a camera (image) or a laser radar. And a steering angle command value generation unit 132 that generates a steering angle command value θref that becomes the target steering angle θt. In addition, the actual steering angle θr detected by the steering angle sensor 14 provided on the column shaft (steering shaft, steering wheel shaft) is input to the steering angle control unit 200 in the EPS side ECU 140 via the ECU 130.
切換指令部131は、舵角制御モードに入ることを識別する信号、例えば運転者の意思をダッシュボードやハンドル周辺に設けたボタンやスイッチ、或いはシフトに設けた駐車モードなどによる車両状態の信号を基に切換指令SWを出力し、切換指令SWをEPS側ECU140内の切換部142に入力する。また、舵角指令値生成部132は、カメラ(画像)、レーザレーダなどのデータを基に公知の手法で舵角指令値θrefを生成し、生成された舵角指令値θrefを目標舵角θtとしてEPS側ECU140内の舵角制御部200に入力する。
The switching command unit 131 receives a signal for identifying that the steering angle control mode is entered, for example, a vehicle state signal by a button or a switch provided on the dashboard or around the steering wheel, or a parking mode provided for a shift. Based on this, the switching command SW is output, and the switching command SW is input to the switching unit 142 in the EPS side ECU 140. The steering angle command value generation unit 132 generates a steering angle command value θref by a known method based on data such as a camera (image) and a laser radar, and the generated steering angle command value θref is a target steering angle θt. To the rudder angle control unit 200 in the EPS side ECU 140.
EPS側ECU140は、操舵トルクTh及び車速Vsに基づいて演算されたアシスト制御指令値Itrefを出力するアシスト制御部141と、操舵トルクTh、目標舵角θt、実舵角θr及びモータ角速度ωrに基づいて舵角制御のための舵角制御指令値Imrefを演算して出力する舵角制御部200と、切換指令SWによってアシスト制御指令値Itref及び舵角制御指令値Imrefを切り換える切換部142と、切換部142からのモータ電流指令値Iref(=Itref又はImref)に基づいてモータ150を駆動制御する電流制御/駆動部143と、回転センサ151からのモータ回転角θsに基づいてモータ速度を求め、モータ速度とギア比を用いて実舵角速度(モータ角速度)ωrを演算するモータ角速度演算部144とを具備している。モータ角速度演算部144は、微分相当の演算の後段に高周波ノイズをカットするためのローパスフィルタ(LPF)を備えている。
The EPS-side ECU 140 outputs an assist control command value Itref calculated based on the steering torque Th and the vehicle speed Vs, and based on the steering torque Th, the target steering angle θt, the actual steering angle θr, and the motor angular speed ωr. A steering angle control unit 200 that calculates and outputs a steering angle control command value Imref for steering angle control, a switching unit 142 that switches between the assist control command value Itref and the steering angle control command value Imref by a switching command SW, and switching A current control / driving unit 143 that drives and controls the motor 150 based on the motor current command value Iref (= Itref or Imref) from the unit 142; a motor speed based on the motor rotation angle θs from the rotation sensor 151; Motor angular speed calculation unit that calculates actual steering angular speed (motor angular speed) ωr using speed and gear ratio 144. The motor angular velocity calculation unit 144 includes a low-pass filter (LPF) for cutting high-frequency noise after the calculation equivalent to differentiation.
舵角制御部200は図4に示すように、目標舵角θtに実舵角θrを追従させるように舵角速度指令値ωcを出力する位置制御部210と、舵角速度指令値ωcに実舵角速度ωrを追従させるように舵角制御指令値Imrefを出力する速度制御部220とで構成されている。また、切換部142は、車両側ECU130の切換指令部131からの切換指令SWに基づいて、アシスト制御部141によるアシスト制御モード(手動操舵制御)と、舵角制御部200による舵角制御モード(位置/速度制御モード)とを切り換え、アシスト制御ではアシスト制御指令値Itrefを出力し、舵角制御では舵角制御指令値Imrefを出力する。
As shown in FIG. 4, the steering angle control unit 200 outputs a steering angular speed command value ωc so that the actual steering angle θr follows the target steering angle θt, and the steering angular speed command value ωc. The speed control unit 220 outputs a steering angle control command value Imref so as to follow ωr. Further, the switching unit 142 is based on a switching command SW from the switching command unit 131 of the vehicle-side ECU 130, and an assist control mode (manual steering control) by the assist control unit 141 and a steering angle control mode (by the steering angle control unit 200). Position / speed control mode), the assist control command value Itref is output in the assist control, and the steering angle control command value Imref is output in the steering angle control.
このような機能を備えた電動パワーステアリング装置において、操舵モードの切換時にスイッチなどにより急に切り換えてしまうとモータ電流指令値Irefが急変動し、ハンドル挙動が不自然になるため、運転者へ違和感を与える。
In an electric power steering apparatus having such a function, if the motor mode command value Iref fluctuates suddenly when the steering mode is switched suddenly by a switch or the like when the steering mode is switched, the steering wheel behavior becomes unnatural. give.
このため、舵角制御指令値とアシスト制御指令値に徐変ゲインを乗じ、徐々に操舵モードを切り換えることによって、モータ電流指令値の急変動を抑制する手法が用いられる。しかし、この手法では、切換中は舵角制御指令値が徐変ゲインで制限されてモータ電流指令値へ出力されるため、舵角制御指令値に対し電流指令値が制限された分だけ出力が小さくなってしまう。この制限により、舵角速度指令値に対し、モータの実舵角速度が遅くなるため、舵角速度指令値と実舵角速度に偏差が発生し、速度制御内のI制御の積分値が蓄積してしまうことで、速度制御から更に大きな舵角制御指令値が出力されてしまう。この結果、徐変ゲインが徐々に大きくなっていく状態では、徐変ゲインによる制限が緩和されていくため、徐変ゲインが大きくなるに従って舵角制御指令値が過剰な値となり、ハンドルが舵角速度指令値に対して過剰に応答し、運転者へ違和感を与えてしまう。
For this reason, a technique is used in which the steering angle control command value and the assist control command value are multiplied by a gradual gain, and the steering mode is gradually switched to suppress sudden fluctuations in the motor current command value. However, in this method, the steering angle control command value is limited by the gradual gain during switching and is output to the motor current command value. Therefore, an output corresponding to the current command value limited to the steering angle control command value is output. It gets smaller. Due to this restriction, the actual steering angular speed of the motor becomes slower than the steering angular speed command value, so that a deviation occurs between the steering angular speed command value and the actual steering angular speed, and the integrated value of I control in the speed control is accumulated. As a result, a larger steering angle control command value is output from the speed control. As a result, when the gradual gain is gradually increased, the restriction due to the gradual gain is relaxed, so the steering angle control command value becomes excessive as the gradual gain increases, and the steering wheel speed It responds excessively to the command value and gives the driver a sense of incongruity.
例えば特許第3912279号公報(特許文献1)では、舵角制御開始時に徐々に舵角速度を増加させるよう制御し、開始時のハンドル急変動による運転者への違和感を低減する手法が提案されている。しかし、特許文献1の手法では、徐変が始まると上限値に達するまで増加し続けるため、I制御の積分値が過剰に蓄積してしまう問題がある。
For example, Japanese Patent No. 3912279 (Patent Document 1) proposes a method of controlling the steering angle speed to be gradually increased at the start of the steering angle control and reducing a sense of discomfort to the driver due to a sudden change in the steering wheel at the start. . However, the technique of Patent Document 1 has a problem that when the gradual change starts, it continues to increase until the upper limit is reached, so that the integral value of I control accumulates excessively.
また、従来の装置は舵角制御モード中に運転者がハンドルを操作し、その操舵トルクが予め設定した所定値を越えたと判断されると舵角制御を中止するようになっている。しかしながら、トルクセンサの出力を所定値と比較するだけでその判断を行うと、トルクセンサのノイズにより、或いはタイヤが小石を踏んだような場合やモータによる舵角制御が行われた場合のハンドルの慣性トルクにより、トルクセンサの出力が一時的に所定値を越えることがあり、その度に舵角制御が中止されてしまう問題がある。このような不都合を回避するために所定値を高めに設定すると、舵角制御モードとアシスト制御モードとが干渉し合って運転者に違和感を与えるだけでなく、舵角制御中に運転者がハンドルを操作しても舵角制御が直ちに中止されなくなる可能性がある。
Further, in the conventional apparatus, the steering angle control is stopped when the driver operates the steering wheel during the steering angle control mode and it is determined that the steering torque exceeds a predetermined value set in advance. However, if the judgment is made only by comparing the output of the torque sensor with a predetermined value, the steering wheel is turned on when the torque sensor noise or when the tire steps on a pebble or when the steering angle control by the motor is performed. There is a problem that the output of the torque sensor may temporarily exceed a predetermined value due to the inertia torque, and the steering angle control is stopped each time. If the predetermined value is set high to avoid such inconvenience, the steering angle control mode and the assist control mode interfere with each other, which not only gives the driver a sense of incongruity, but also allows the driver to handle the steering wheel during the steering angle control. Even if is operated, the steering angle control may not be stopped immediately.
このような問題を解決する自動操舵装置として、例えば特許第3845188号公報(特許文献2)が提案されている。特許文献2に開示された装置は、目標位置までの車両の移動軌跡を記憶又は算出する移動軌跡設定手段と、車輪を転舵するアクチュエータ(モータ)と、運転者がハンドルに加える操舵トルクを検出する操舵トルク検出手段(トルクセンサ)と、移動軌跡設定手段により設定された移動軌跡に基づいてアクチュエータの駆動を制御すると共に、予め設定された所定値以上の操舵トルクが所定時間以上に亘って検出されたときに移動軌跡に基づくアクチュエータの制御を中止するアクチュエータ制御手段とを備えた車両の自動操舵装置において、所定値を複数種類設定し、各所定値に対応して所定時間を変更するようになっている。
For example, Japanese Patent No. 3845188 (Patent Document 2) has been proposed as an automatic steering device that solves such a problem. The apparatus disclosed in Patent Document 2 detects a movement trajectory setting means for storing or calculating a movement trajectory of a vehicle up to a target position, an actuator (motor) for turning a wheel, and a steering torque applied to a steering wheel by a driver. The driving torque of the actuator is controlled based on the movement torque set by the steering torque detection means (torque sensor) and the movement locus setting means, and a steering torque greater than a predetermined value is detected over a predetermined time. In a vehicle automatic steering apparatus having an actuator control means for stopping the control of the actuator based on the movement trajectory when set, a plurality of predetermined values are set, and the predetermined time is changed corresponding to each predetermined value It has become.
しかしながら、特許文献2に開示された装置では、運転者の操舵トルクに応じた所定時間を経過すると、舵角制御を中止するようになっている。所定値を複数種類設定し、各所定値に対応して所定時間を変更する煩雑さがあり、演算負荷が大きいといった問題がある。
However, in the device disclosed in Patent Document 2, the steering angle control is stopped when a predetermined time corresponding to the steering torque of the driver has elapsed. There are problems that a plurality of types of predetermined values are set and the predetermined time is changed corresponding to each predetermined value, and the calculation load is large.
また、特許文献3には、従来の自動操舵技術の適用範囲を低速域に拡大すると共に、運転中の操舵操作に係わる操作性、安全性及び快適性を確保することが示され、角度制御方式に従って据え切りした後、操舵トルク閾値判定手段によりトルク制御方式に切り換えることが開示されている。しかしながら、特許文献3における切り換え条件は、操舵トルクτの値が連続N+1回だけ定数τ0(操舵トルク判定閾値)を上回った時であり、操舵トルクの絶対値をとり、その絶対値をトルク閾値で判定する点及び絶対値の積分値を積分閾値と比較する場合の優位性に関する言及や示唆はない。
Further, Patent Document 3 shows that the application range of the conventional automatic steering technology is expanded to a low speed region, and that operability, safety and comfort related to the steering operation during driving are ensured. Is switched to the torque control method by the steering torque threshold value determination means. However, the switching condition in Patent Document 3 is when the value of the steering torque τ exceeds the constant τ0 (steering torque determination threshold) for N + 1 consecutive times, and takes the absolute value of the steering torque, and the absolute value is the torque threshold value. There is no mention or suggestion of superiority when comparing the judgment point and the integral value of the absolute value with the integral threshold value.
更に特許文献4は、運転者の操舵力がアシスト操舵力に対抗して保舵する力を超えたことを検出したときに、自車両のアシスト操舵力の解除と判定する障害物回避支援装置であり、特許文献4には、操舵トルクが予め決められた基準閾値を超えてからの操舵トルクの積分値を算出することが開示されている。しかしながら、特許文献4は基準閾値を超えた部分の操舵トルクの積分であり、また、操舵トルクの絶対値に関するものではない。また、特許文献5は、車輪を転舵するモータの制御状態が切り換わった瞬間にハンドルが急激に軽くなるのを防止する自動操舵装置に関するものであり、操舵トルクの変化に対して2つの閾値が設定されている。しかしながら、特許文献5の積分は、車速とヨーレートに関するものであり、操舵トルクの積分と異なり、しかも、第2の閾値は不感帯領域に設定される必要がある。
Furthermore, Patent Document 4 is an obstacle avoidance assistance device that determines that the assist steering force of the host vehicle is released when it is detected that the steering force of the driver exceeds the force to hold the steering against the assist steering force. Yes, Patent Document 4 discloses that an integrated value of the steering torque after the steering torque exceeds a predetermined reference threshold is calculated. However, Patent Document 4 is the integral of the steering torque in the portion exceeding the reference threshold, and is not related to the absolute value of the steering torque. Further, Patent Document 5 relates to an automatic steering device that prevents a steering wheel from being suddenly lightened at the moment when a control state of a motor that steers a wheel is switched. Is set. However, the integration of Patent Document 5 relates to the vehicle speed and the yaw rate, and unlike the integration of the steering torque, the second threshold needs to be set in the dead zone region.
本発明は上述のような事情よりなされたものであり、本発明の目的は、舵角制御モードからアシスト制御モードへの切換及びアシスト制御モードから舵角制御モードへの切換をそれぞれ徐変ゲインを用いて徐変すると共に、絶対値と信号全体の積分を用いて、舵角制御モード中においても手入力の判定を行って円滑にアシスト制御モードに移行するようにし、モータ電流指令値に対して意図しないハンドルの変動を抑制し、運転者への違和感を低減する高機能な電動パワーステアリング装置を提供することにある。
The present invention has been made under the circumstances described above, and an object of the present invention is to provide a gradual gain for switching from the steering angle control mode to the assist control mode and from the assist control mode to the steering angle control mode. Using the absolute value and the integral of the entire signal, the manual input is judged even during the rudder angle control mode to smoothly shift to the assist control mode, and the motor current command value is An object of the present invention is to provide a highly functional electric power steering device that suppresses unintended steering wheel fluctuations and reduces the uncomfortable feeling to the driver.
本発明は、アシスト制御モードと舵角制御モードを切換指令により切り換える機能を有し、アシスト制御部で演算された第1のアシスト制御指令値と、舵角制御部で演算された第1の舵角制御指令値とでモータ電流指令値を生成し、前記モータ電流指令値によりモータを駆動して車両の操舵系をアシスト制御する電動パワーステアリング装置に関し、本発明の上記目的は、操舵トルク及び前記切換指令に基づいて、舵角制御の位置速度制御で用いる速度指令徐変ゲイン及び速度制御徐変ゲインと、制御モードの切換時に用いる舵角制御出力徐変ゲイン及びアシスト制御出力徐変ゲインとを生成する切換判定/徐変ゲイン生成部を備え、前記舵角制御部は、舵角指令値を目標舵角として入力し、前記目標舵角及び実舵角の角度偏差に基づいて舵角速度指令値を出力する位置制御部と、前記舵角速度指令値を前記速度指令徐変ゲインに応じて徐変すると共に、上下限値を制限して出力する徐変制限部と、前記徐変制限部から出力される目標舵角速度を、実舵角速度及び前記速度徐変ゲインに基づいて処理する舵角速度制御部と、前記舵角速度制御部から出力される速度制御電流値を前記舵角制御出力徐変ゲインで徐変して第2の舵角制御指令値を出力する第1の徐変出力部とで構成され、前記アシスト制御部から出力される前記第1のアシスト制御指令値を前記アシスト制御出力徐変ゲインで徐変し、第2のアシスト制御指令値を出力する第2の徐変出力部を備え、前記第2の舵角制御指令値及び前記第2のアシスト制御指令値に基づいて前記モータ電流指令値を生成し、前記切換判定/徐変ゲイン生成部は手入力判定部を有し、前記手入力判定部は、前記操舵トルクをフィルタ処理するLPFと、前記LPFを経た操舵トルクの絶対値をトルク閾値と比較すると共に、出力信号として出力するトルク値比較部と、前記出力信号の全体を積分して前記積分出力値を出力する積分演算部と、前記積分演算部からの前記積分出力値と積分閾値を比較することにより、操舵トルク判定信号を出力する切換判定部とで構成されていることにより達成される。
The present invention has a function of switching between an assist control mode and a steering angle control mode by a switching command, and includes a first assist control command value calculated by the assist control unit and a first rudder calculated by the steering angle control unit. An electric power steering apparatus that generates a motor current command value with an angle control command value, drives the motor with the motor current command value, and assists the steering system of the vehicle, and the object of the present invention is to provide the steering torque and the Based on the switching command, a speed command gradual change gain and a speed control gradual change gain used in the position / speed control of the steering angle control, and a steering angle control output gradual change gain and an assist control output gradual change gain used when switching the control mode. A switching determination / gradual gain generating unit for generating, the steering angle control unit inputs a steering angle command value as a target steering angle, and based on an angular deviation between the target steering angle and the actual steering angle A position control unit that outputs an angular velocity command value; a gradual change limiting unit that gradually changes the rudder angular velocity command value according to the speed command gradual change gain; A steering angular speed control unit that processes a target steering angular speed output from the control unit based on an actual steering angular speed and the speed gradual gain, and a speed control current value output from the steering angular speed control unit. A first gradual change output unit that gradually changes with a variable gain and outputs a second steering angle control command value, and the first assist control command value output from the assist control unit is controlled by the assist control. A second gradual change output unit that gradually changes with an output gradual change gain and outputs a second assist control command value is provided, based on the second steering angle control command value and the second assist control command value. Generating the motor current command value, and The gradual gain generating unit has a manual input determining unit, which compares the LPF that filters the steering torque with the absolute value of the steering torque that has passed through the LPF, and a torque threshold value. By comparing the integral output value and the integral threshold value from the integral calculation unit, a torque value comparison unit that outputs as a signal, an integral calculation unit that integrates the entire output signal and outputs the integral output value, This is achieved by comprising a switching determination unit that outputs a steering torque determination signal.
本発明の電動パワーステアリング装置によれば、舵角制御指令値を舵角制御出力徐変ゲインで徐変し、アシスト制御指令値をアシスト制御出力徐変ゲインで徐変し、舵角制御における舵角速度指令値及び舵角制御電流値をそれぞれ速度指令徐変ゲイン及び速度制御徐変ゲインで徐変し、ハンドル制振処理をした制振信号を舵角制御指令値に加味しているので、円滑なモード切換が可能であり、モータ電流指令値に対して意図しないハンドルの変動を抑制し、運転者への違和感を低減することができる。
According to the electric power steering apparatus of the present invention, the steering angle control command value is gradually changed by the steering angle control output gradual change gain, and the assist control command value is gradually changed by the assist control output gradual change gain. Since the angular velocity command value and the steering angle control current value are gradually changed with the speed command gradual change gain and the speed control gradual change gain, respectively, and the vibration damping signal subjected to the handle vibration damping process is added to the steering angle control command value, smooth Mode switching is possible, unintentional fluctuations in the steering wheel with respect to the motor current command value can be suppressed, and discomfort to the driver can be reduced.
また、操舵トルクの絶対値に基づく手入力の判定を行い、徐変ゲインを生成する切換判定/徐変ゲイン生成部を設けているので、速度制御内の積分制御の積分値が過剰に蓄積することもなく、モータ電流指令値に対して意図しないハンドルの変動を抑制することができる。
In addition, since there is provided a switching determination / gradual gain generating unit that performs manual input determination based on the absolute value of the steering torque and generates a gradual gain, the integral value of the integral control in the speed control accumulates excessively. In addition, unintended steering wheel fluctuations can be suppressed with respect to the motor current command value.
本発明は、舵角制御指令値を舵角制御出力徐変ゲインで徐変し、アシスト制御指令値をアシスト制御出力徐変ゲインで徐変し、舵角制御部内の位置制御部からの舵角速度指令値を速度指令徐変ゲインで徐変し、徐変後の舵角速度指令値の上下限値を、速度指令徐変ゲインに応じてリミッタで制限した目標舵角速度を舵角速度制御部に入力する。舵角速度制御部では更に、目標舵角速度及び実舵角速度に基づいた制御演算を行うと共に、速度制御徐変ゲインで徐変して速度制御電流値を出力し、ハンドル制振部からの制振信号を速度制御電流値に加算して舵角制御指令値を出力している。
The present invention gradually changes the steering angle control command value with the steering angle control output gradual gain, gradually changes the assist control command value with the assist control output gradual gain, and the steering angular velocity from the position control unit in the steering angle control unit. The command value is gradually changed with the speed command gradual gain, and the upper and lower limits of the steering angular velocity command value after the gradual change are input to the steering angular velocity control unit with the target rudder angular velocity limited by the limiter according to the speed command gradual gain. . The rudder angular speed control unit further performs control calculation based on the target rudder angular speed and the actual rudder angular speed, and gradually changes with a speed control gradual change gain to output a speed control current value. Is added to the speed control current value to output a steering angle control command value.
また、本発明では操舵トルク及び切換指令を入力する切換判定/徐変ゲイン生成部を設けており、切換判定/徐変ゲイン生成部は操舵トルク及び切換指令に基づいて速度指令徐変ゲイン、速度制御徐変ゲイン、舵角制御出力徐変ゲイン及びアシスト制御出力徐変ゲインを生成している。速度指令徐変ゲイン及び速度制御徐変ゲインは舵角制御部にける位置速度制御で用いられ、舵角制御出力徐変ゲイン及びアシスト制御出力徐変ゲインは制御モードの切換時に用いられる。これら各徐変ゲインの生成では、操舵トルクに基づいて手入力の判定を行う手入力判定部を用いており、手入力判定部はLPFを経て操舵トルクの絶対値を求め、操舵方向に関連しない絶対値の全体を積分し、絶対値をトルク閾値と比較すると共に、絶対値がトルク閾値以上となったときに絶対値全体の積分演算を開始し、その積分値を積分閾値と比較してトルク判定信号を得ている。これにより、舵角制御モード中にハンドル操舵が開始された場合、外乱トルク(ノイズ)に影響を受けることなく確実にかつ円滑にアシスト制御モードに移行することができる。
In the present invention, a switching determination / gradual change gain generation unit for inputting a steering torque and a switching command is provided. The switching determination / gradual change gain generation unit is based on the steering torque and the switching command. A control gradual gain, a steering angle control output gradual gain, and an assist control output gradual gain are generated. The speed command gradual change gain and the speed control gradual change gain are used for position speed control in the steering angle control unit, and the steering angle control output gradual change gain and the assist control output gradual change gain are used when the control mode is switched. Each of these gradually changing gains is generated using a manual input determination unit that determines a manual input based on the steering torque. The manual input determination unit obtains an absolute value of the steering torque through the LPF and is not related to the steering direction. The entire absolute value is integrated, the absolute value is compared with the torque threshold value, and when the absolute value is equal to or greater than the torque threshold value, the integral calculation of the entire absolute value is started, and the integrated value is compared with the integral threshold value to determine the torque. A judgment signal is obtained. Thereby, when steering wheel is started during the steering angle control mode, it is possible to shift to the assist control mode surely and smoothly without being affected by the disturbance torque (noise).
更に、本発明では舵角制御部の前段(若しくは舵角制御部内)に、舵角指令値に対してリミット処理及びレートリミット処理を行うと共に、ハンドル振動を除去する前処理部を設けており、前処理された目標舵角に対して位置速度制御を実施しているので、急なハンドル操舵に対しても違和感を与えることはない。また、舵角制御部内の位置制御部にハンドル振動除去部及びフィードフォワード(FF)フィルタを設けている実施形態では、ハンドル振動(10Hz前後)を抑制した舵角制御指令値を生成できる。
Furthermore, in the present invention, a pre-processing unit that performs limit processing and rate limit processing on the steering angle command value and removes steering wheel vibration is provided in the front stage of the steering angle control unit (or in the steering angle control unit). Since the position / speed control is performed on the pre-processed target rudder angle, there is no sense of incongruity even when the steering wheel is suddenly steered. Further, in an embodiment in which a steering wheel vibration removing unit and a feed forward (FF) filter are provided in the position control unit in the steering angle control unit, a steering angle control command value that suppresses steering vibration (around 10 Hz) can be generated.
舵角制御部からの舵角制御指令値に対しては、舵角制御出力徐変ゲインを乗じて徐変し、アシスト制御部からのアシスト制御指令値に対しては、アシスト制御出力徐変ゲインを乗じて徐変し、舵角制御出力徐変ゲインとアシスト制御出力徐変ゲインを逆の増加減特性としている。つまり、舵角制御出力徐変ゲインとアシスト制御出力徐変ゲインは制御モードの切換時に、各割合(舵角制御出力徐変ゲインは0.0(0%)~1.0(100%)、アシスト制御出力徐変ゲインは1.0(100%)~0.0(%))の合計値が原則的に1.0、つまり100%の関係で、かつ逆の関係で増加減(線形若しくは非線形)する特性となっている。モードの切換時には舵角制御出力徐変ゲインとアシスト制御出力徐変ゲインは逆の関係で増加減するが、舵角制御モード中においては、両者の合計値は1.0(100%)の関係でなくても良い。
The steering angle control command value from the steering angle control unit is gradually changed by multiplying the steering angle control output gradual change gain, and the assist control output gradual change gain is applied to the assist control command value from the assist control unit. The steering angle control output gradual change gain and the assist control output gradual change gain have opposite increase and decrease characteristics. In other words, the steering angle control output gradual change gain and the assist control output gradual change gain are set at respective ratios (the steering angle control output gradual change gain is 0.0 (0%) to 1.0 (100%), The assist control output gradual change gain is 1.0 (100%) to 0.0 (%)) in principle in a relationship of 1.0, that is, 100%, and vice versa. (Non-linear) characteristics. When the mode is switched, the steering angle control output gradual gain and the assist control output gradual gain increase and decrease in the opposite relationship, but during the steering angle control mode, the total value of both is 1.0 (100%). Not necessarily.
以下に、本発明の実施の形態を、図面を参照して詳細に説明する。
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
図5は本発明の構成例を図3に対応させて示しており、本発明では新たに、操舵トルクTh及び切換指令SWを入力して切換判定を行うと共に、舵角制御における速度徐変用の徐変ゲインSG(SG1,SG2)及び制御モード切換徐変用の徐変ゲインSWG(SWG1,SWG2)を出力して管理する切換判定/徐変ゲイン生成部400と、車両側ECU130内の舵角指令値生成部132からの舵角指令値θrefを処理して、目標舵角θtを出力する前処理部500とが設けられている。速度徐変用の徐変ゲインSG(SG1,SG2)は舵角制御部200に入力され、モード切換徐変用の徐変ゲインSWG(SWG1,SWG2)は切換部142に入力される。
FIG. 5 shows an example of the configuration of the present invention corresponding to FIG. 3. In the present invention, a steering torque Th and a switching command SW are newly input to make a switching determination, and for gradual speed change in steering angle control. Gradual change gain SG (SG1, SG2) and gradual change gain SWG (SWG1, SWG2) for gradual change of control mode are output and managed, and a rudder in the vehicle-side ECU 130 A pre-processing unit 500 that processes the steering angle command value θref from the angle command value generation unit 132 and outputs the target steering angle θt is provided. The gradual change gain SG (SG1, SG2) for gradual speed change is input to the steering angle control unit 200, and the gradual change gain SWG (SWG1, SWG2) for mode change gradual change is input to the switching unit 142.
切換判定/徐変ゲイン生成部400は例えば図6に示すような構成であり、操舵トルクThを入力して後述するトルク判定信号TDを出力する手入力判定部410と、操舵トルクTh、トルク判定信号TD及び切換指令SWに基づいて速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2を生成して出力する徐変ゲイン生成部430と、トルク判定信号TD及び切換指令SWに基づいて舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2を演算して出力する徐変ゲイン切換生成部420とで構成されている。切換指令SWは舵角制御モードからアシスト制御モードへの切換、若しくはアシスト制御モードから舵角制御モードへの切換を指示し、トルク判定信号TDは舵角制御モード中にハンドルが操舵された時に、アシスト制御モードへの切換を指示する。
The switching determination / gradual gain generating unit 400 is configured as shown in FIG. 6, for example, and includes a manual input determining unit 410 that inputs a steering torque Th and outputs a torque determination signal TD described later, a steering torque Th, and a torque determination. A gradual gain generator 430 that generates and outputs a speed command gradual change gain SG1 and a speed control gradual change gain SG2 based on the signal TD and the switching command SW, and a steering angle control based on the torque determination signal TD and the switching command SW. A gradual change gain switching generator 420 that calculates and outputs the output gradual change gain SWG1 and the assist control output gradual change gain SWG2. The switching command SW instructs switching from the steering angle control mode to the assist control mode, or switching from the assist control mode to the steering angle control mode, and the torque determination signal TD is obtained when the steering wheel is steered during the steering angle control mode. Instructs switching to the assist control mode.
手入力判定部410は図7に示すような構成となっており、操舵トルクThの外乱トルク(ノイズ)を除去するためのLPF(ローパスフィルタ)411と、LPF411から出力される操舵トルクThaの絶対値|Tha|を求める絶対値部412と、操舵トルクThaの絶対値|Tha|を所定のトルク閾値Tthと比較して出力信号Ct又は過去値初期化信号Piを出力するトルク値比較部413と、出力信号Ctの上下限値を制限し、過大な信号を入力しないようにするリミッタ414と、リミッタ414からの積分入力値Ctaの全体を積分する積分演算部415と、積分演算部415で積分された積分出力値Ioutを所定の積分閾値Sthと比較して操舵トルク判定信号TDを出力する切換判定部416とで構成されている。積分演算部415は純積分でも、1次LPFで構成される擬似積分でも良い。積分演算部415はリミッタ414からの積分入力値Ctaの全体、つまり値0からの積分入力値Cta(=Cta-0)を時系列に沿って積分演算し、積分演算部415から出力される積分出力値Ioutを積分閾値Sthと比較することで、外乱トルクの影響を受け難くしている。
The manual input determination unit 410 has a configuration as shown in FIG. 7, and an LPF (low-pass filter) 411 for removing disturbance torque (noise) of the steering torque Th and the absolute value of the steering torque Tha output from the LPF 411. An absolute value unit 412 for obtaining a value | Tha |, a torque value comparing unit 413 that compares the absolute value | Tha | of the steering torque Tha with a predetermined torque threshold Tth and outputs an output signal Ct or a past value initialization signal Pi. The limiter 414 that limits the upper and lower limit values of the output signal Ct so as not to input an excessive signal, the integration calculation unit 415 that integrates the entire integral input value Cta from the limiter 414, and the integration by the integration calculation unit 415 The switching determination unit 416 that compares the integrated output value Iout with a predetermined integration threshold Sth and outputs a steering torque determination signal TD.The integral calculation unit 415 may be a pure integral or a pseudo-integral composed of a first-order LPF. The integral calculation unit 415 integrates the entire integral input value Cta from the limiter 414, that is, the integral input value Cta (= Cta-0) from the value 0 in time series, and the integral output from the integral calculation unit 415 By comparing the output value Iout with the integration threshold value Sth, it is made difficult to be influenced by disturbance torque.
タイヤが縁石や石等に衝突した場合、ハンドルの慣性トルクにより操舵トルクThが一時的に所定値を超えたり、或いは操舵トルクThが所定値に満たない場合に、自動操舵制御が切り換わってしまったり、切り換わり難くなるのを回避するために、操舵トルクThの外乱トルク(ノイズ)を除去するLPF411を設けている。LPF411は1次でも、2次以上でも良く、また、IIR(Infinite Impulse Response)型若しくはFIR(Finite Impulse Response)型の外乱トルク(ノイズ)を除去するフィルタで、実装可能なものであれば良い。LPF411の効果については、具体例をもって後述する。
When the tire collides with a curb or stone, the steering torque Th temporarily exceeds a predetermined value due to the inertia torque of the steering wheel, or the automatic steering control is switched when the steering torque Th does not reach the predetermined value. An LPF 411 that removes disturbance torque (noise) of the steering torque Th is provided in order to avoid turning around and becoming difficult to switch. The LPF 411 may be primary or secondary, and may be any filter that removes disturbance torque (noise) of IIR (Infinite Impulse Response) type or FIR (Finite Impulse Response) type and can be mounted. The effect of the LPF 411 will be described later with a specific example.
トルク値比較部413は、操舵トルクThaの絶対値|Tha|をトルク閾値Tthと比較し、絶対値|Tha|がトルク閾値Tth以上となったときに、積分演算部415は、リミッタ414からの積分入力値Ctaの積分動作を開始して積分を継続し、絶対値|Tha|がトルク閾値Tthよりも小さくなったときに、積分演算部415はトルク値比較部413からの過去値初期化信号Piによって積分値を0に初期化される。即ち、トルク値比較部413は下記のような動作を行う。操舵トルクThaの絶対値|Tha|を用いて比較しているので、ハンドルの操舵方向を考慮することなく、大きさのみで判定を行うことができる。
(数1)
|Tha|≧Tthのとき、出力信号Ct=|Tha|
|Tha|<Tthのとき、出力信号Ct=0、過去値初期化信号Pi出力
トルク値比較部413から過去値初期化信号Piが出力されると、積分演算部415内の過去値保持部(Z-1)が0に初期化される。また、切換判定部416は、積分演算部415からの積分出力値Ioutを積分閾値Sthと比較し、積分出力値Ioutが積分閾値Sth以上のときに切換条件が成立し、舵角制御モードからアシスト制御モードに切り換え、積分出力値Ioutが積分閾値Sthよりも小さいときに切換条件不成立とし、舵角制御モードを継続する。即ち、切換判定部416は下記のような動作を行う。
(数2)
Iout≧Sthのとき、切換条件成立の操舵トルク判定信号TD
Iout<Sthのとき、切換条件不成立の操舵トルク判定信号TD
手入力判定部410からの操舵トルク判定信号TDは、操舵トルクTh及び切換指令SWと共に徐変ゲイン生成部430に入力され、徐変ゲイン生成部430は速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2を生成する。速度指令徐変ゲインSG1は、 主にアシスト制御から舵角制御への切換時に、円滑な切換を実現するために用いられ、位置制御部(210)から出力される舵角速度指令値ωcに対して徐変と上下限値の設定に使用される。また、速度制御徐変ゲインSG2は、切換時の舵角速度制御部(220)内の積分値の蓄積の影響を緩和するために、舵角速度制御部(220)の中の積分関係の信号(例えば積分出力値(Iout))に乗算され、円滑な切換を実現するために用いられる。 The torquevalue comparison unit 413 compares the absolute value | Tha | of the steering torque Tha with the torque threshold value Tth. When the absolute value | Tha | becomes equal to or greater than the torque threshold value Tth, the integration calculation unit 415 The integration operation of the integration input value Cta is started and integration is continued. When the absolute value | Tha | becomes smaller than the torque threshold value Tth, the integration calculation unit 415 receives the past value initialization signal from the torque value comparison unit 413. The integration value is initialized to 0 by Pi. That is, the torque value comparison unit 413 performs the following operation. Since the comparison is made using the absolute value | Tha | of the steering torque Tha, the determination can be made only by the magnitude without considering the steering direction of the steering wheel.
(Equation 1)
When | Tha | ≧ Tth, the output signal Ct = | Tha |
When | Tha | <Tth, output signal Ct = 0, past value initialization signal Pi output
When the past value initialization signal Pi is output from the torquevalue comparison unit 413, the past value holding unit (Z −1 ) in the integral calculation unit 415 is initialized to zero. Further, the switching determination unit 416 compares the integral output value Iout from the integral calculation unit 415 with the integration threshold value Sth, and when the integral output value Iout is equal to or greater than the integration threshold value Sth, the switching condition is established, and the steering angle control mode assists. When the integral output value Iout is smaller than the integral threshold value Sth, the switching condition is not satisfied and the steering angle control mode is continued. That is, the switching determination unit 416 performs the following operation.
(Equation 2)
When Iout ≧ Sth, the steering torque determination signal TD for satisfying the switching condition
When Iout <Sth, the steering torque determination signal TD that does not satisfy the switching condition
A steering torque determination signal TD from the manualinput determination unit 410 is input to the gradual gain generation unit 430 together with the steering torque Th and the switching command SW, and the gradual gain generation unit 430 includes the speed command gradual change gain SG1 and the speed control gradual change. A gain SG2 is generated. The speed command gradual change gain SG1 is mainly used to realize smooth switching at the time of switching from assist control to steering angle control, and with respect to the steering angular speed command value ωc output from the position control unit (210). Used for gradual change and upper / lower limit setting. Further, the speed control gradual gain SG2 is an integral-related signal (for example, in the steering angular speed control unit (220)) in order to reduce the influence of accumulation of integral values in the steering angular speed control unit (220) at the time of switching. Is multiplied by the integral output value (Iout)) and used to realize smooth switching.
(数1)
|Tha|≧Tthのとき、出力信号Ct=|Tha|
|Tha|<Tthのとき、出力信号Ct=0、過去値初期化信号Pi出力
トルク値比較部413から過去値初期化信号Piが出力されると、積分演算部415内の過去値保持部(Z-1)が0に初期化される。また、切換判定部416は、積分演算部415からの積分出力値Ioutを積分閾値Sthと比較し、積分出力値Ioutが積分閾値Sth以上のときに切換条件が成立し、舵角制御モードからアシスト制御モードに切り換え、積分出力値Ioutが積分閾値Sthよりも小さいときに切換条件不成立とし、舵角制御モードを継続する。即ち、切換判定部416は下記のような動作を行う。
(数2)
Iout≧Sthのとき、切換条件成立の操舵トルク判定信号TD
Iout<Sthのとき、切換条件不成立の操舵トルク判定信号TD
手入力判定部410からの操舵トルク判定信号TDは、操舵トルクTh及び切換指令SWと共に徐変ゲイン生成部430に入力され、徐変ゲイン生成部430は速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2を生成する。速度指令徐変ゲインSG1は、 主にアシスト制御から舵角制御への切換時に、円滑な切換を実現するために用いられ、位置制御部(210)から出力される舵角速度指令値ωcに対して徐変と上下限値の設定に使用される。また、速度制御徐変ゲインSG2は、切換時の舵角速度制御部(220)内の積分値の蓄積の影響を緩和するために、舵角速度制御部(220)の中の積分関係の信号(例えば積分出力値(Iout))に乗算され、円滑な切換を実現するために用いられる。 The torque
(Equation 1)
When | Tha | ≧ Tth, the output signal Ct = | Tha |
When | Tha | <Tth, output signal Ct = 0, past value initialization signal Pi output
When the past value initialization signal Pi is output from the torque
(Equation 2)
When Iout ≧ Sth, the steering torque determination signal TD for satisfying the switching condition
When Iout <Sth, the steering torque determination signal TD that does not satisfy the switching condition
A steering torque determination signal TD from the manual
また、操舵トルク判定信号TDは切換指令SWと共に徐変ゲイン切換生成部420に入力され、徐変ゲイン切換生成部420で舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2が生成され、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2は切換部142に入力される。舵角制御出力徐変ゲインSWG1は、 舵角制御部200のリミッタ203から出力される舵角制御指令値(電流指令値)Imrefと乗算されて徐変され、 アシスト制御と舵角制御の切換動作を円滑に行い、運転者への違和感、安全性等を実現するために用いられる。アシスト制御出力徐変ゲインSWG2はアシスト制御部141から出力されるアシスト制御指令値(電流指令値)Itrefと乗算されて徐変され、舵角制御とアシスト制御の切換動作を円滑にするのと、自動運転中の運転者による操舵介入を実現するために用いられる。
Further, the steering torque determination signal TD is input to the gradual change gain switching generation unit 420 together with the switching command SW, and the gradual change gain switching generation unit 420 generates the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2. The steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are input to the switching unit 142. The steering angle control output gradual change gain SWG1 is gradually changed by being multiplied by the steering angle control command value (current command value) Imref output from the limiter 203 of the steering angle control unit 200, and switching operation between the heel assist control and the steering angle control. It is used to achieve smoothness and a sense of incongruity and safety for the driver. The assist control output gradual change gain SWG2 is multiplied by the assist control command value (current command value) Itref output from the assist control unit 141 to be gradually changed, thereby facilitating the switching operation between the steering angle control and the assist control. Used to realize steering intervention by the driver during automatic driving.
一方、舵角制御部200、切換部142及び前処理部500の構成例は図8であり、前処理部500は、舵角指令値生成部132からの自動運転などのための舵角指令値θrefに対して、通信エラー等による異常な値、過剰な値が舵角制御部200に入力するのを防止するため上下限値を制限するリミッタ510と、リミッタ510からの舵角指令値θref1の急変によって舵角制御出力としての舵角制御電流指令値が急激に変動することを避けるため、舵角指令値θref1をレートリミット処理するレートリミッタ520と、レートリミット後の舵角指令値θref2に含まれるハンドル振動周波数成分を低減するためのハンドル振動除去部530とで構成されている。
On the other hand, a configuration example of the steering angle control unit 200, the switching unit 142, and the preprocessing unit 500 is shown in FIG. 8, and the preprocessing unit 500 uses the steering angle command value for automatic driving from the steering angle command value generation unit 132. A limiter 510 that limits upper and lower limit values to prevent an abnormal value due to a communication error or an excessive value from being input to the steering angle control unit 200 with respect to θref, and a steering angle command value θref1 from the limiter 510 In order to avoid a sudden change in the steering angle control current command value as the steering angle control output due to a sudden change, the steering angle command value θref1 is included in the rate limiter 520 that performs rate limit processing, and the steering angle command value θref2 after the rate limit. And a handle vibration removing unit 530 for reducing a handle vibration frequency component.
レートリミッタ520は、急なハンドル挙動による巻き込み等の、運転者への安全性向上にも繋がる。また、アシスト制御モードから舵角制御モードへの切換時に、レートリミッタ過去値を実舵角θrに初期化する。これにより、切換時にハンドル振動除去部530から出力される目標舵角θtと実舵角θrとがほぼ一致することで、舵角制御電流指令値の急変の発生を抑え、結果的にハンドルの急変動を防止することができる。
The rate limiter 520 also leads to an improvement in the safety to the driver, such as entanglement due to a sudden steering behavior. Also, the rate limiter past value is initialized to the actual steering angle θr when switching from the assist control mode to the steering angle control mode. As a result, the target steering angle θt output from the steering wheel vibration removal unit 530 at the time of switching substantially coincides with the actual steering angle θr, so that the sudden change in the steering angle control current command value is suppressed, and as a result, the steering wheel suddenly changes. Variations can be prevented.
レートリミッタ520は例えば図9に示すような構成となっており、舵角指令値θref1は減算部520-1に加算入力され、過去値との減算結果である舵角指令値θt1が変化分設定部520-2で変化分θt2の設定をされる。変化分設定部520-2は、保持部(Z-1)520-4からの過去値と入力(θref1)の差分θt1を設定し、加算部520-3での変化分θt2と過去値との加算結果を新たな舵角指令値θref2として出力する。変化分設定部520-2は、変化分が設定された上限及び下限を超えないようにするものであり、その特性は演算周期T毎に入力(舵角指令値)θref1との差分を求め、変化分設定部520-2の上限及び下限の範囲外の場合には、差分を過去値に加算することを繰返し行うことにより、図10に示すような階段状に出力θref2を変化させて、最終的に出力θref2を舵角指令値θref1に一致させる。また、入力(舵角指令値)θref1との差分が変化分設定部520-2の上限及び下限の範囲内の場合には、変化分θt2=差分θt1を出力し、過去値に加算するので、その結果出力θref2と入力(舵角指令値)θref1は一致する。これらの結果、舵角指令値θreftが急激に変化しても、急激に変化する舵角指令値θref2を滑らかに変化させることができ、急激な電流変化を防止し、運転者の自動運転の不安感を低減させる機能を果たしている。
For example, the rate limiter 520 is configured as shown in FIG. 9, and the steering angle command value θref1 is added to the subtraction unit 520-1, and the steering angle command value θt1, which is a subtraction result with the past value, is set as a change amount. The change amount θt2 is set by the unit 520-2. The change setting unit 520-2 sets the difference θt1 between the past value from the holding unit (Z −1 ) 520-4 and the input (θref1), and the change θt2 between the addition unit 520-3 and the past value is set. The addition result is output as a new steering angle command value θref2. The change setting unit 520-2 prevents the change from exceeding the set upper limit and lower limit, and its characteristic is to obtain a difference from the input (steering angle command value) θref1 every calculation cycle T. When the change amount setting unit 520-2 is outside the upper limit and lower limit ranges, the output θref2 is changed in a stepwise manner as shown in FIG. Therefore, the output θref2 is made to coincide with the steering angle command value θref1. When the difference from the input (steering angle command value) θref1 is within the upper and lower limits of the change setting unit 520-2, the change θt2 = the difference θt1 is output and added to the past value. As a result, the output θref2 and the input (steering angle command value) θref1 coincide. As a result, even if the steering angle command value θreft changes abruptly, the rapidly changing steering angle command value θref2 can be changed smoothly, preventing a sudden current change and the driver's anxiety about automatic driving. It plays a function that reduces the feeling.
レートリミッタ520の後段のハンドル振動除去部530は、ローパスフィルタ(LPF)、ノッチフィルタ、或いは位相遅れ補償により、操舵トルクThに含まれる振動周波数成分を低減させる。ハンドル振動除去部530からは、上述のように前処理された目標舵角θtが出力される。
The steering wheel vibration removal unit 530 following the rate limiter 520 reduces a vibration frequency component included in the steering torque Th by a low-pass filter (LPF), a notch filter, or phase delay compensation. From the steering wheel vibration removing unit 530, the target rudder angle θt preprocessed as described above is output.
前処理部500からの目標舵角θtは、図11に詳細構成を示す舵角制御部200の位置制御部210内の減算部210-1に加算入力される。減算部210-1には実舵角θrが減算入力されており、減算部210-1で目標舵角θt及び実舵角θrの角度偏差θeが求められ、角度偏差θeは比例部210-2で比例処理(ゲインKpp)され、位置制御部210から舵角速度指令値ωcが出力される。舵角速度指令値ωcは乗算部201に入力され、乗算部201で速度指令徐変ゲインSG1で徐変され、徐変された舵角速度指令値ωcaは上下限値を速度指令徐変ゲインSG1に応じて制限するリミッタ202に入力される。リミッタ202は例えば図12に示すように、速度指令徐変ゲインSG1に応じて正負の上下限値が制限される。即ち、速度指令徐変ゲインSG1が小さくなるに従って、リミッタ202の制限値も小さくなるように制限され、速度指令徐変ゲインSG1が大きくなればリミッタ202の制限値も大きく制限される。また、リミッタ202の動作に関しては、例を挙げて後述する。
The target rudder angle θt from the pre-processing unit 500 is added and inputted to the subtraction unit 210-1 in the position control unit 210 of the rudder angle control unit 200 whose detailed configuration is shown in FIG. The subtraction unit 210-1 receives the subtraction input of the actual steering angle θr, and the subtraction unit 210-1 obtains the target steering angle θt and the angle deviation θe of the actual steering angle θr, and the angle deviation θe is the proportional unit 210-2. And the proportional control (gain Kpp) is performed, and the steering angular velocity command value ωc is output from the position control unit 210. The steering angular velocity command value ωc is input to the multiplication unit 201, and is gradually changed by the multiplication unit 201 with the speed command gradual change gain SG1, and the gradually changed steering angular velocity command value ωca has upper and lower limit values according to the speed command gradual change gain SG1. To the limiter 202 to be limited. For example, as shown in FIG. 12, the limiter 202 has its positive and negative upper and lower limits limited according to the speed command gradual change gain SG1. That is, as the speed command gradual change gain SG1 is reduced, the limit value of the limiter 202 is also reduced. When the speed command gradual change gain SG1 is increased, the limit value of the limiter 202 is also greatly limited. The operation of the limiter 202 will be described later with an example.
リミッタ202で上下限値を制限された目標舵角速度ωcbは、実舵角速度ωr及び速度制御徐変ゲインSG2と共に舵角速度制御部220に入力される。舵角速度制御部220は図11に詳細を示すように、目標舵角速度ωcbから実舵角速度ωrを減算する減算部221と、減算部221の減算結果である速度偏差Dfを積分処理(Kvi/s)して補償する積分部222と、実舵角速度ωrを比例処理(Kvp)して補償する比例部225と、積分部222の積分結果である舵角制御電流値Ir1から比例部225の比例結果である舵角制御電流値Ir2を減算する減算部223と、減算部223の減算結果である速度制御電流値Imref0を速度制御徐変ゲインSG2により徐変し、速度制御電流値Imref1を出力する乗算部224とで構成されている。乗算部224からの速度制御電流値Imref1は加算部204に入力され、ハンドル制振部440からの制振処理された制振信号(電流値)Thdと加算され、加算結果である舵角制御指令値Imref2が、過出力防止のためのリミッタ203で上下限値を制限され、舵角制御指令値Imrefが出力される。
The target rudder angular velocity ωcb whose upper and lower limits are limited by the limiter 202 is input to the rudder angular velocity control unit 220 together with the actual rudder angular velocity ωr and the speed control gradual change gain SG2. As shown in detail in FIG. 11, the steering angular speed control unit 220 integrates the subtraction unit 221 that subtracts the actual steering angular speed ωr from the target steering angular speed ωcb, and the speed deviation Df that is the subtraction result of the subtraction unit 221 (Kvi / s ) To compensate, the proportional unit 225 to compensate the actual steering angular velocity ωr by proportional processing (Kvp), and the proportional result of the proportional unit 225 from the steering angle control current value Ir1 that is the integration result of the integration unit 222. A subtracting unit 223 for subtracting the steering angle control current value Ir2 and a speed control current value Imref0 as a subtraction result of the subtracting unit 223 are gradually changed by the speed control gradually changing gain SG2, and a speed control current value Imref1 is output. Part 224. The speed control current value Imref1 from the multiplication unit 224 is input to the addition unit 204, added to the vibration suppression signal (current value) Thd subjected to vibration suppression processing from the steering wheel vibration suppression unit 440, and the steering angle control command that is the addition result. The upper and lower limit values of the value Imref2 are limited by the limiter 203 for preventing excessive output, and the steering angle control command value Imref is output.
ハンドル制振部440は、コラム軸の トーションバーに基づく操舵トルクThを制振処理し、自動操舵中のハンドル振動の制振効果を一層向上するために設けられている。 ハンドル制振部440の構成は例えば図13であり、操舵トルクThをゲイン(Kv)するゲイン部441と、ゲイン部441からの操舵トルクKv・Thを位相補償する位相補償部442とで構成されている。位相補償部442は例えば1次フィルタで構成され、トーションバーの捩れを解消する方向に制振信号Thdが出力される。 また、1次フィルタ以外にも、ハンドルの制振効果が出るものであれば適用可能である。
The handle damping unit 440 is provided for damping the steering torque Th based on the column shaft saddle torsion bar and further improving the damping effect of the handle vibration during automatic steering. The structure of the steering wheel damping unit 440 is, for example, FIG. 13 and includes a gain unit 441 that gains the steering torque Th (Kv) and a phase compensation unit 442 that compensates the phase of the steering torque Kv · Th from the gain unit 441. ing. The phase compensation unit 442 is configured by, for example, a primary filter, and outputs a vibration suppression signal Thd in a direction to eliminate torsion of the torsion bar.以外 In addition to the primary filter, any filter can be used as long as it has a handle damping effect.
切換部142は図8に示すように、舵角制御指令値Imrefに舵角制御出力徐変ゲインSWG1を乗算する乗算部142-1と、アシスト制御指令値Itrefにアシスト制御出力徐変ゲインSWG2を乗算する乗算部142-2と、乗算部142-1からの舵角制御指令値Imrefg及び乗算部142-2からのアシスト制御指令値Itrefgを加算してモータ電流指令値Irefを出力する加算部142-3とで構成されている。
As shown in FIG. 8, the switching unit 142 is configured to multiply the steering angle control command value Imref by the steering angle control output gradual change gain SWG1, and to multiply the assist control command value Itref by the assist control output gradual change gain SWG2. A multiplying unit 142-2 for multiplying, and an adding unit 142 for adding the steering angle control command value Imrefg from the multiplying unit 142-1 and the assist control command value Itrefg from the multiplying unit 142-2 to output a motor current command value Iref. -3.
このような構成において、先ず切換判定/徐変ゲイン生成部400の動作例を図14のフローチャートを参照して説明する。
In such a configuration, first, an operation example of the switching determination / gradual gain generating unit 400 will be described with reference to the flowchart of FIG.
先ず切換指令部131から切換指令SWが入力された否かが判定され(ステップS1)、切換指令SWが入力されていない場合には、舵角制御モードにおいて運転者によりハンドルが操舵(左右)されると、操舵トルクThが手入力判定部410に入力され(ステップS2)、手入力判定部410は前述の数2及び後述するような手入力の判定を行い(ステップS10)、判定の結果、制御モードの切換となるトルク判定信号TDが出力されない場合は(ステップS20)、切換判定/徐変ゲイン生成部400で速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2を生成して舵角制御モードの値に遷移し(ステップS21)、速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2は舵角制御部200に入力され(ステップS22)、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2は切換部142に入力される(ステップS25)。これにより、舵角制御部200による舵角制御が継続される。
First, it is determined whether or not the switching command SW is input from the switching command unit 131 (step S1). If the switching command SW is not input, the steering wheel is steered (left and right) by the driver in the steering angle control mode. Then, the steering torque Th is input to the manual input determination unit 410 (step S2), and the manual input determination unit 410 determines the above-described Equation 2 and the manual input as described later (step S10). If the torque determination signal TD for switching the control mode is not output (step S20), the switching determination / gradual change gain generation unit 400 uses the speed command gradual change gain SG1, the speed control gradual change gain SG2, and the steering angle control output gradual change. The gain SWG1 and the assist control output gradual change gain SWG2 are generated to change to the value of the steering angle control mode (step S21), and the speed command gradual change gain SG1 and Speed control gradual change gain SG2 is input to the steering angle control unit 200 (step S22), and the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 is inputted to the switching unit 142 (step S25). Thereby, the steering angle control by the steering angle control part 200 is continued.
また、上記ステップS1において切換指令SWが入力されている場合、或いは上記ステップS20において操舵トルク判定信号TDにより制御モードの切換と判断された場合、切換判定/徐変ゲイン生成部400で速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2を生成してアシスト制御モードの値に遷移し(ステップS24)、速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2は舵角制御部200に入力され(ステップS22)、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2は切換部142に入力される(ステップS25)。これにより、アシスト制御部141によるアシスト制御が実施される。
When the switching command SW is input in step S1 or when it is determined that the control mode is switched based on the steering torque determination signal TD in step S20, the switching determination / gradual change gain generation unit 400 uses the speed command gradually. The variable gain SG1, the speed control gradual change gain SG2, the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are generated and transitioned to the value of the assist control mode (step S24), and the speed command gradual change gain SG1 is generated. The speed control gradual change gain SG2 is input to the steering angle control unit 200 (step S22), and the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are input to the switching unit 142 (step S25). Thereby, assist control by the assist control unit 141 is performed.
ここで、本発明で使用する各徐変ゲインに関して、自動運転状態(舵角制御とアシスト制御の両方が介在している状態)中に、運転者による手入力の検知後の各徐変ゲインについて、アシスト制御モードに移行する実施例を図15に示して説明する。図15(A)は舵角制御出力徐変ゲインSWG1、速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2の徐変動作を示しており、図15(B)はアシスト制御出力徐変ゲインSWG2の徐変動作を示している。時点t10において手入力判定が完了し、舵角制御モードからアシスト制御モードへ移行する状態を示し、時点t11に移行が完了してアシスト制御モードに切り換わる様子である。徐変ゲインSG1,SG2及びSWG1については、手入力判定後、図15(A)に示すように100%から徐々に減少していき、0%に遷移する。本実施形態では直線的に変化させているが、切換動作を円滑にするために、クロソイド曲線などによるS字曲線で遷移させても良いし、1次のLPF(カットオフ周波2[Hz])を通した値を各徐変ゲインとしても良い。ただし、徐変ゲインSG1,SG2,SWG1は同じ特性で連動させる必要はなく、アシスト制御出力徐変ゲインSWG2も含めてそれぞれ独立させた特性にしても良い。また、アシスト制御出力徐変ゲインSWG2については、自動運転状態においては常に0%である必要はなく、0%より大きい値、例えば図15(B)に示すように50%としても良い。アシスト制御出力徐変ゲインSWG2を調整要素として、例えば50%に設定することで、舵角制御モードにおける操舵介入時の引っ掛かり感を抑えることが可能となる。手入力判定後は、50%から100%へ遷移する。
Here, regarding each gradually changing gain used in the present invention, each gradually changing gain after detection of manual input by the driver during the automatic driving state (a state in which both the steering angle control and the assist control are present). An embodiment for shifting to the assist control mode will be described with reference to FIG. 15A shows the gradual change operation of the steering angle control output gradual change gain SWG1, the speed command gradual change gain SG1, and the speed control gradual change gain SG2. FIG. 15B shows the assist control output gradual change gain SWG2. The gradual change operation is shown. Manual input determination is completed at time t 10, shows a state of transition from the steering angle control mode to the assist control mode is a state in which the switches are shifted to time t 11 is finished to assist control mode. The gradual gains SG1, SG2 and SWG1 are gradually decreased from 100% and transitioned to 0% as shown in FIG. 15A after manual input determination. In this embodiment, it is linearly changed. However, in order to make the switching operation smooth, the transition may be made with an S-shaped curve such as a clothoid curve, or a primary LPF (cutoff frequency 2 [Hz]). It is good also as each gradually changing gain the value which passed. However, the gradual change gains SG1, SG2, and SWG1 do not need to be interlocked with the same characteristic, and may include independent characteristics including the assist control output gradual change gain SWG2. Further, the assist control output gradual change gain SWG2 does not always have to be 0% in the automatic operation state, and may be a value larger than 0%, for example, 50% as shown in FIG. By setting the assist control output gradual change gain SWG2 as an adjustment factor, for example, 50%, it becomes possible to suppress a feeling of being caught during steering intervention in the steering angle control mode. After manual input determination, the transition is from 50% to 100%.
次に、図7に示す手入力判定部410の動作例(図14のステップS10)を図16のフローチャートを参照して説明する。
Next, an example of the operation of the manual input determination unit 410 shown in FIG. 7 (step S10 in FIG. 14) will be described with reference to the flowchart in FIG.
操舵トルクThが入力されると(ステップS10-1)、LPF411で外乱トルク(ノイズ)の除去を行い(ステップS10-2)、絶対値部412でLPF411からの操舵トルクThaの絶対値|Tha|を求める(ステップS10-3)。トルク値比較部413にはトルク閾値Tthが予め入力されており、トルク値比較部413は絶対値|Tha|がトルク閾値Tth以上であるか否かを判定し(ステップS10-4)、絶対値|Tha|がトルク閾値Tth以上である場合には、出力信号Ctを絶対値|Tha|として積分演算部415に入力し、積分演算部415で積分動作を行う(ステップS10-5)。また、絶対値|Tha|がトルク閾値Tthよりも小さい場合には、出力信号Ctを0にして積分しないようにすると共に、過去値初期化信号Piを出力して積分演算部415を初期化して0にする(ステップS10-6)。初期化は積分演算部415内の過去値保持部(Z-1)を0にリセットすることにより行われる。
When steering torque Th is input (step S10-1), disturbance torque (noise) is removed by LPF 411 (step S10-2), and absolute value | Tha | of steering torque Tha from LPF 411 is output by absolute value unit 412. Is obtained (step S10-3). A torque threshold value Tth is input in advance to the torque value comparison unit 413, and the torque value comparison unit 413 determines whether or not the absolute value | Tha | is equal to or greater than the torque threshold value Tth (step S10-4). If | Tha | is equal to or greater than the torque threshold value Tth, the output signal Ct is input as an absolute value | Tha | to the integration calculation unit 415, and the integration calculation unit 415 performs an integration operation (step S10-5). When the absolute value | Tha | is smaller than the torque threshold value Tth, the output signal Ct is set to 0 so as not to integrate, and the past value initialization signal Pi is output to initialize the integration calculation unit 415. Set to 0 (step S10-6). Initialization is performed by resetting the past value holding unit (Z −1 ) in the integral calculation unit 415 to zero.
積分演算部415からの積分出力値Ioutは切換判定部416に入力され、切換判定部416において積分出力値Ioutが積分閾値Sth以上であるか否かが判定される(ステップS10-7)。積分出力値Ioutが積分閾値Sth以上である場合には数2の切換条件が成立し(ステップS10-8)、操舵トルク判定信号TDにより各徐変ゲインSG1,SG2,SWG1,SWG2を更新し(ステップS10-9)、舵角制御モードからアシスト制御モードに切り換える(ステップS10-10)。また、積分出力値Ioutが積分閾値Sthよりも小さい場合には数2の切換条件が不成立であり、制御モードの切換は行われない(ステップS10-11)。
The integral output value Iout from the integral calculation unit 415 is input to the switching determination unit 416, and the switching determination unit 416 determines whether or not the integral output value Iout is greater than or equal to the integration threshold value Sth (step S10-7). When the integral output value Iout is equal to or greater than the integral threshold value Sth, the switching condition of Equation 2 is satisfied (step S10-8), and the gradually changing gains SG1, SG2, SWG1, SWG2 are updated by the steering torque determination signal TD ( In step S10-9, the steering angle control mode is switched to the assist control mode (step S10-10). On the other hand, when the integral output value Iout is smaller than the integral threshold value Sth, the switching condition of Equation 2 is not satisfied and the control mode is not switched (step S10-11).
図17は、LPF411で外乱トルク(ノイズ)を除去された操舵トルクTh(Tha)のトルク閾値Tthに対する時間変化の一例を積分動作の関連で示しており、スタートから時点t1までは操舵トルクThがトルク閾値Tthよりも小さいので積分は行われない。時点t1から時点t2までの間は、操舵トルクThがトルク閾値Tth以上であるので入力信号全体の積分が行われるが、全体の積分値が積分閾値Sthよりも小さいので切換条件は不成立となっている。積分出力値Ioutは図17における斜線部の面積に相当しており、操舵トルクTh(絶対値)の総計となっている。そして、時点t2から時点t3までは操舵トルクThがトルク閾値Tthよりも小さいので積分は行われず、時点t3以降は操舵トルクThがトルク閾値Tth以上であるので積分が行われる。時点t4において積分値が所定値(積分閾値Sth)以上となり、切換条件が成立する様子を示している。つまり、図17の斜線部の面積が積分値相当となっているが、時点t2においては積分値が積分閾値Sthよりも小さくて切換条件は不成立、時点t4において積分値が積分閾値Sth以上となり、切換条件が成立する例を示している。
Figure 17 shows the context of the integration operation of an example of a temporal change with respect to the torque threshold value Tth of the disturbance torque steering torque Th removed (noise) (Tha) in LPF411, from the start to the time point t 1 is the steering torque Th Is smaller than the torque threshold value Tth, so no integration is performed. Between time t 1 to time t 2 is the steering torque Th is the integration of the entire input signal since torque threshold value Tth or higher is performed, switching the whole of the integral value is less than the integral threshold value Sth conditions and not satisfied It has become. The integrated output value Iout corresponds to the area of the shaded portion in FIG. 17 and is the total of the steering torque Th (absolute value). Then, from time t 2 to time t 3 the steering torque Th is integrated is not performed is smaller than the torque threshold value Tth, the time t 3 subsequent integration since the steering torque Th is a torque threshold value Tth or more is performed. Integrated value becomes a predetermined value (integration threshold Sth) above at time t 4, it shows how the switching condition is satisfied. That is, although the area of the hatched portion in FIG. 17 has a integral value equivalent, the integral value at time t 2 is switching condition smaller than the integral threshold value Sth is not satisfied, the integrated value at time t 4 the integral threshold Sth or In this example, the switching condition is satisfied.
次に、図8及び図11に示す舵角制御部200の動作例を、図18のフローチャートを参照して説明する。本例では舵角指令値θrefは前処理部500で前処理され、前処理された目標舵角θtが舵角制御部200に入力されているが、前処理部500を舵角制御部200に含めた構成でも良い。
Next, an example of the operation of the rudder angle control unit 200 shown in FIGS. 8 and 11 will be described with reference to the flowchart of FIG. In this example, the steering angle command value θref is preprocessed by the preprocessing unit 500, and the preprocessed target steering angle θt is input to the steering angle control unit 200, but the preprocessing unit 500 is input to the steering angle control unit 200. A configuration including this may be used.
目標舵角θt、実舵角θr、実舵角速度ωr、操舵トルクTh、速度指令徐変ゲインSG1、速度制御徐変ゲインSG2が入力され(ステップS30)、位置制御部210で位置制御される(ステップS31)。即ち、目標舵角θtと実舵角θrの角度偏差θeが減算部211で求められ、角度偏差θeが比例部212で比例処理される。位置制御部210で位置制御された舵角速度指令値ωcは乗算部201において速度指令徐変ゲインSG1で徐変され(ステップS32)、徐変された舵角速度指令値ωcaはリミッタ202において、速度指令徐変ゲインSG1に応じてリミット処理される(ステップS33)。リミット処理された目標舵角速度ωcbは舵角速度制御部220内の減算部221に入力され、実舵角速度ωrとの速度偏差Dfが演算される(ステップS34)。速度偏差Dfは積分部222に入力されて積分処理され(ステップS35)、実舵角速度ωrは比例部225で比例処理され(ステップS36)、積分処理された舵角制御電流値Ir1から比例処理された舵角制御電流値Ir2が減算部223で減算され(ステップS37)、減算で求められた速度制御電流値Imref0が乗算部224に入力され、速度制御徐変ゲインSG2で徐変される(ステップS40)。徐変された速度制御電流値Imref1は加算部204に入力される。
The target rudder angle θt, actual rudder angle θr, actual rudder angular velocity ωr, steering torque Th, speed command gradual change gain SG1, and speed control gradual change gain SG2 are input (step S30), and the position control unit 210 controls the position ( Step S31). That is, the angle deviation θe between the target rudder angle θt and the actual rudder angle θr is obtained by the subtracting unit 211, and the angle deviation θe is proportionally processed by the proportional unit 212. The steering angular speed command value ωc whose position is controlled by the position control unit 210 is gradually changed by the speed command gradually changing gain SG1 in the multiplication unit 201 (step S32), and the gradually changed steering angular speed command value ωca is converted by the limiter 202 in the speed command. Limit processing is performed according to the gradual change gain SG1 (step S33). The target rudder angular velocity ωcb subjected to the limit processing is input to the subtracting unit 221 in the rudder angular velocity control unit 220, and a speed deviation Df from the actual rudder angular velocity ωr is calculated (step S34). The speed deviation Df is input to the integration unit 222 and integrated (step S35), and the actual steering angular speed ωr is proportionally processed by the proportional unit 225 (step S36), and proportionally processed from the integrated steering angle control current value Ir1. The steering angle control current value Ir2 is subtracted by the subtraction unit 223 (step S37), and the speed control current value Imref0 obtained by subtraction is input to the multiplication unit 224 and gradually changed by the speed control gradual change gain SG2 (step S37). S40). The gradually changed speed control current value Imref1 is input to the adding unit 204.
また、操舵トルクThはハンドル制振部440に入力されて制振処理され(ステップS41)、制振処理された制振信号Thdは加算部204に入力されて速度制御電流値Imref1と加算される(ステップS42)。加算された舵角制御指令値Imref2はリミッタ203で上下限値を制限され(ステップS43)、舵角制御指令値Imrefが出力される(ステップS44)。
Further, the steering torque Th is input to the steering wheel damping unit 440 and subjected to vibration damping processing (step S41), and the vibration damping signal Thd subjected to vibration damping processing is input to the adding unit 204 and added to the speed control current value Imref1. (Step S42). The upper and lower limit values of the added steering angle control command value Imref2 are limited by the limiter 203 (step S43), and the steering angle control command value Imref is output (step S44).
なお、目標舵角θt、実舵角θr、実舵角速度ωr、操舵トルクTh、速度指令徐変ゲインSG1、速度制御徐変ゲインSG2の入力順番は適宜変更可能である。
The input order of the target rudder angle θt, actual rudder angle θr, actual rudder angular speed ωr, steering torque Th, speed command gradual change gain SG1, and speed control gradual change gain SG2 can be changed as appropriate.
上述の実施形態では前処理部500内にハンドル振動除去部530を設けているが、図19に示すようにハンドル振動除去部530を削除した前処理部500Aとし、図20に示すような位置制御部200Aの構成としても良い。即ち、前処理部500Aは、リミッタ410及びレートリミッタ420で構成されており、位置制御部200Aは、ハンドル振動除去部211、減算部212、フィードフォワード(FF)フィルタ213、ゲイン(Kpp)部214及び加算部215で構成されている。
In the above-described embodiment, the handle vibration removing unit 530 is provided in the pre-processing unit 500. However, as shown in FIG. 19, the pre-processing unit 500A in which the handle vibration removing unit 530 is deleted is used, and position control as shown in FIG. The configuration of the unit 200A may be used. That is, the pre-processing unit 500A includes a limiter 410 and a rate limiter 420, and the position control unit 200A includes a handle vibration removal unit 211, a subtraction unit 212, a feed forward (FF) filter 213, and a gain (Kpp) unit 214. And an adder 215.
前処理部500Aからの目標舵角θtは、位置制御部210A内のハンドル振動除去部211及びFFフィルタ213に入力される。自動操舵中、舵角指令が変化しているときに、舵角指令値θrefに、トーションバーのバネ性やハンドルの慣性モーメントによる振動を励起する周波数(約10Hz前後)成分が発生する。 舵角指令値θrefの前処理部500A(リミッタ510、レートリミッタ520)の後の舵角指令値である目標舵角θtに含まれるハンドル振動周波数成分を低減するために、ハンドル振動除去部211が設けられている。ハンドル振動除去部211はLPF、ノッチフィルタ又は位相遅れ補償により、振動周波数成分を低減させる。ハンドル振動除去部211からの舵角信号θt1は減算部212に加算入力される。また、FFフィルタ213は、舵角制御の追従性を向上させる舵角速度指令値を演算するために用いられているが、擬似的な微分演算とゲイン部を直列に組み合わせて設定しても良い。この場合、微分演算によるノイズ除去のために、LPFを微分演算の後ろに配置する。更に後退差分やHPF(ハイパスフィルタ)によるものでも良く、ハンドル振動除去部211同様に、目標舵角θtに含まれる、ンドル振動の周波数成分(10Hz前後)を低減するフィルタを含ませても良い。例えば1次LPF(カットオフ周波数2Hz)、ノッチフィルタ(中心周波数10Hz)、位相遅れ補償フィルタなどを直列に接続した構成である。
The target rudder angle θt from the preprocessing unit 500A is input to the handle vibration removal unit 211 and the FF filter 213 in the position control unit 210A. During automatic steering, when the rudder angle command is changing, a frequency component (about 10 Hz) that excites vibration due to the spring property of the torsion bar and the inertial moment of the steering wheel is generated in the rudder angle command value θref. In order to reduce the steering wheel vibration frequency component included in the target steering angle θt that is the steering angle command value after the steering angle command value θref pre-processing unit 500A (limiter 510, rate limiter 520), the steering wheel vibration removal unit 211 Is provided. The handle vibration removal unit 211 reduces the vibration frequency component by LPF, notch filter, or phase delay compensation. The steering angle signal θt1 from the steering wheel vibration removing unit 211 is added and input to the subtracting unit 212. The FF filter 213 is used to calculate a steering angular velocity command value that improves the followability of the steering angle control, but may be set by combining a pseudo differential calculation and a gain unit in series. In this case, the LPF is arranged after the differential operation in order to remove noise by the differential operation. Further, a backward difference or HPF (high-pass filter) may be used, and a filter for reducing the frequency component (around 10 Hz) of the middle vibration included in the target rudder angle θt may be included in the same manner as the steering wheel vibration removing unit 211. For example, a first-order LPF (cut-off frequency 2 Hz), a notch filter (center frequency 10 Hz), a phase lag compensation filter, and the like are connected in series.
このような構成において、前処理部500A及び位置制御部210Aの動作例を、図21のフローチャートを参照して説明する。
In such a configuration, an operation example of the preprocessing unit 500A and the position control unit 210A will be described with reference to the flowchart of FIG.
先ず舵角指令値θrefが入力され(ステップS30-1)、前処理部500Aはリミッタ510及びレートリミッタ520で前処理され(ステップS30-2)、前処理された目標舵角θtが出力される(ステップS30-3)。目標舵角θtは位置制御部210A内のハンドル振動除去部211に入力され、目標舵角θtのハンドル振動周波数成分がハンドル振動除去部211で除去され(ステップS31-1)、減算部212でハンドル振動除去部211からの舵角信号θt1と実舵角θtとの角度偏差θeが求められ(ステップS31-2)、角度偏差θeは比例部214で比例処理(ゲインKpp)される(ステップS31-3)。比例処理された角度偏差θegは加算部215に入力される。また、目標舵角θtはFFフィルタ213に入力されフィルタリング処理され(ステップS31-4)、フィルタリング処理された角度信号θt2が加算部215に入力されて角度偏差θegと加算され(ステップS31-5)、加算された舵角速度指令値ωcが出力される(ステップS31-6)。
First, the steering angle command value θref is input (step S30-1), the preprocessing unit 500A is preprocessed by the limiter 510 and the rate limiter 520 (step S30-2), and the preprocessed target steering angle θt is output. (Step S30-3). The target rudder angle θt is input to the handle vibration removal unit 211 in the position control unit 210A, the handle vibration frequency component of the target rudder angle θt is removed by the handle vibration removal unit 211 (step S31-1), and the subtraction unit 212 handles the handle. An angle deviation θe between the steering angle signal θt1 from the vibration removing unit 211 and the actual steering angle θt is obtained (step S31-2), and the angle deviation θe is proportionally processed (gain Kpp) by the proportional unit 214 (step S31−). 3). The proportionally processed angle deviation θeg is input to the adder 215. The target rudder angle θt is input to the FF filter 213 and filtered (step S31-4), and the filtered angle signal θt2 is input to the adder 215 and added to the angle deviation θeg (step S31-5). The added steering angular speed command value ωc is output (step S31-6).
以上では各部の詳細動作例を説明したが、本発明の全体動作を、図5の構成図及び図22のフローチャートを参照して説明する。
Although the detailed operation example of each unit has been described above, the overall operation of the present invention will be described with reference to the configuration diagram of FIG. 5 and the flowchart of FIG.
操舵系の動作がスタートすると、アシスト制御部141によるアシスト制御が実施され(ステップS100)、アシスト制御指令値Itrefを用いて電流制御/駆動部143によりモータ150が駆動される(ステップS101)。上記動作は切換指令部131より切換指令SWが出力されるまで繰り返される(ステップS102)。切換指令SWは、操舵トルクThと共に切換判定/徐変ゲイン生成部400に入力される。
When the operation of the steering system starts, assist control by the assist control unit 141 is performed (step S100), and the motor 150 is driven by the current control / drive unit 143 using the assist control command value Itref (step S101). The above operation is repeated until a switching command SW is output from the switching command unit 131 (step S102). The switching command SW is input to the switching determination / gradual change gain generation unit 400 together with the steering torque Th.
舵角制御モードとなり、切換指令部131より切換指令SWが出力されると、舵角指令値生成部132から前処理部500(若しくは500A)に舵角指令値θrefが入力され(ステップS103)、前処理部500で前処理された目標舵角θtが舵角制御部200に入力され(ステップS104)、舵角センサ14から実舵角θrが、車両側ECU130を経由して舵角制御部200に入力され(ステップS105)、モータ角速度演算部144からの実舵角速度ωrが舵角制御部200に入力される(ステップS106)。また、操舵トルクThは切換判定/徐変ゲイン生成部400へ入力され(ステップS107)、切換判定/徐変ゲイン生成部400は上述した手法で速度指令徐変ゲインSG1、速度制御徐変ゲインSG2、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2を生成し(ステップS108)、速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2を舵角制御部200に入力し、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2を切換部142に入力する。舵角制御部200は上述した演算処理で舵角制御指令値Imrefを生成し(ステップS110)、舵角制御指令値Imrefは切換部142に入力される。
When the steering angle control mode is entered and the switching command SW is output from the switching command unit 131, the steering angle command value θref is input from the steering angle command value generation unit 132 to the pre-processing unit 500 (or 500A) (step S103). The target rudder angle θt preprocessed by the pre-processing unit 500 is input to the rudder angle control unit 200 (step S104), and the actual rudder angle θr from the rudder angle sensor 14 passes through the vehicle ECU 130 and the rudder angle control unit 200. (Step S105), the actual steering angular velocity ωr from the motor angular velocity calculation unit 144 is input to the steering angle control unit 200 (step S106). Further, the steering torque Th is input to the switching determination / gradual change gain generation unit 400 (step S107), and the switching determination / gradual change gain generation unit 400 uses the above-described method to perform the speed command gradual change gain SG1 and the speed control gradual change gain SG2. Then, the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 are generated (step S108), the speed command gradual change gain SG1 and the speed control gradual change gain SG2 are input to the steering angle control unit 200, and the steering angle The control output gradual change gain SWG 1 and the assist control output gradual change gain SWG 2 are input to the switching unit 142. The steering angle control unit 200 generates the steering angle control command value Imref by the above-described arithmetic processing (step S110), and the steering angle control command value Imref is input to the switching unit 142.
切換部142には、アシスト制御部141からのアシスト制御指令値Itref及び舵角制御部200からの舵角制御指令値Imrefが入力されていると共に、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2が入力されており、前述した関係で徐変されてアシスト制御から舵角制御に切り換えられる(ステップS111)。そして、舵角制御に切り換えられ、舵角制御の操舵が実施され(ステップS112)、前述した手入力の判定が行われ(ステップS113)、積分値が積分閾値Sthに達するまで上記動作が繰り返される(ステップS114)。積分値が積分閾値Sthに達すると、舵角制御出力徐変ゲインSWG1及びアシスト制御出力徐変ゲインSWG2による徐変により、舵角制御からアシスト制御に切り換えられる(ステップS120)。
The switching unit 142 is input with the assist control command value Itref from the assist control unit 141 and the steering angle control command value Imref from the steering angle control unit 200, as well as the steering angle control output gradually changing gain SWG1 and the assist control output. Gradual change gain SWG2 is input, and is gradually changed according to the above-described relationship to switch from assist control to steering angle control (step S111). Then, the control is switched to the steering angle control, the steering of the steering angle control is performed (step S112), the above-described manual input determination is performed (step S113), and the above operation is repeated until the integral value reaches the integration threshold value Sth. (Step S114). When the integrated value reaches the integration threshold value Sth, the steering angle control is switched to the assist control by the gradual change by the steering angle control output gradual change gain SWG1 and the assist control output gradual change gain SWG2 (step S120).
上記動作の更に詳細な動作例、特にリミッタ202及び切換部142の動作例を図23のフローチャートを参照して説明する。ここでは、前処理部500(若しくは500A)及び切換判定/徐変ゲイン生成部400の動作は、上述の説明と重複しているので省略している。図15の例では、舵角制御状態でのアシスト制御出力徐変ゲインSWG2を50%として説明しているが、図23では0%として説明する。
A more detailed operation example of the above operation, in particular, an operation example of the limiter 202 and the switching unit 142 will be described with reference to the flowchart of FIG. Here, the operations of the pre-processing unit 500 (or 500A) and the switching determination / gradual change gain generation unit 400 are omitted because they overlap the above description. In the example of FIG. 15, the assist control output gradual change gain SWG2 in the steering angle control state is described as 50%, but in FIG. 23, it is described as 0%.
先ず目標舵角θt、実舵角θr、実舵角速度ωrが入力され(ステップS200)、次いで速度指令徐変ゲインSG1、速度制御徐変ゲインSG2、舵角制御出力徐変ゲインSWG1、アシスト制御出力徐変ゲインSWG2が入力される(ステップS201)。これら入力の順序は適宜変更可能である。位置制御部210は目標舵角θtに実舵角θrを追従するように位置制御され、位置制御部210から舵角速度指令値ωcが出力される(ステップS202)。舵角速度指令値ωcは乗算部201に入力され、乗算部201からの舵角速度指令値ωcaがリミッタ202に入力される。舵角速度指令値ωcaはリミッタ202に入力され、以下のようにリミッタ202で上下限値を制限される。即ち、リミッタ202には速度指令徐変ゲインSG1が入力されており、速度指令徐変ゲインSG1を先ず前回値から加算(演算初回の前回値=0%)し(ステップS203)(後述する図24及び図25のように時系列に対して線形に速度指令徐変ゲインSG1を変化させる場合、加算値は一定値で良い。)、速度指令徐変ゲインSG1が100%以上の場合は、100%に制限する(ステップS204、S205)。速度指令徐変ゲインSG1が閾値以上であるか否かを判定し(ステップS206)、速度指令徐変ゲインSG1が閾値以上である場合には、リミッタ制限値を前回値から加算し(ステップS207)(後述する図24及び図25のように時系列に対して線形に速度指令徐変ゲインSG1を変化させる場合、加算値は一定値で良い。)、リミッタ制限値が制限値2以上であるか否かを判定する(ステップS208)。リミッタ制限値が制限値2以上である場合には、リミッタ制限値を制限値2とする(ステップS209)。
First, a target steering angle θt, an actual steering angle θr, and an actual steering angular speed ωr are input (step S200), and then a speed command gradual change gain SG1, a speed control gradual change gain SG2, a steering angle control output gradual change gain SWG1, and an assist control output. The gradually changing gain SWG2 is input (step S201). The order of these inputs can be changed as appropriate. The position control unit 210 is position-controlled so that the actual steering angle θr follows the target steering angle θt, and the steering angle speed command value ωc is output from the position control unit 210 (step S202). The steering angular velocity command value ωc is input to the multiplication unit 201, and the steering angular velocity command value ωca from the multiplication unit 201 is input to the limiter 202. The steering angular velocity command value ωca is input to the limiter 202, and the upper and lower limit values are limited by the limiter 202 as follows. That is, the speed command gradual change gain SG1 is input to the limiter 202, and the speed command gradual change gain SG1 is first added from the previous value (the previous value of the first calculation = 0%) (step S203) (FIG. 24 described later). When the speed command gradual change gain SG1 is changed linearly with respect to the time series as shown in FIG. 25, the addition value may be a constant value.) When the speed command gradual change gain SG1 is 100% or more, 100% (Steps S204 and S205). It is determined whether or not the speed command gradual change gain SG1 is greater than or equal to a threshold value (step S206). If the speed command gradual change gain SG1 is greater than or equal to the threshold value, the limiter limit value is added from the previous value (step S207). (When the speed command gradual change gain SG1 is changed linearly with respect to time series as shown in FIGS. 24 and 25 to be described later, the addition value may be a constant value.) Is the limiter limit value equal to or greater than the limit value 2? It is determined whether or not (step S208). If the limiter limit value is greater than or equal to the limit value 2, the limiter limit value is set to the limit value 2 (step S209).
その後、乗算部201において速度指令徐変ゲインSG1で徐変する(ステップS210)。乗算部201からの徐変後の舵角速度指令値ωcaはリミッタ202に入力されて上下限値を制限される(ステップS211)。リミッタ202からの目標舵角速度ωcbは、実舵角速度ωrと共に舵角速度制御部220に入力され、実舵角速度ωrを目標舵角速度ωcbに追従させる速度制御が実施される。
Thereafter, the multiplier 201 gradually changes with the speed command gradually changing gain SG1 (step S210). The steering angular velocity command value ωca after the gradual change from the multiplication unit 201 is input to the limiter 202 and the upper and lower limit values are limited (step S211). The target rudder angular velocity ωcb from the limiter 202 is input to the rudder angular velocity control unit 220 together with the actual rudder angular velocity ωr, and speed control for causing the actual rudder angular velocity ωr to follow the target rudder angular velocity ωcb is performed.
舵角速度制御部220では速度偏差Dfが演算されると共に、前述のように積分補償された舵角制御電流値Ir1及び比例補償された舵角制御電流値Ir2が演算され、その偏差である速度制御電流値Imref0が演算される(ステップS212)。速度制御電流値Imref0は速度制御徐変ゲインSG2により乗算部224で徐変され、徐変された速度制御電流値Imref1が出力され、速度制御電流値Imref1は加算部204に入力される(ステップS213)。また、操舵トルクThに基づく制振処理が実施され、制振処理後の制振信号Thdが加算部204で速度制御電流値Imref1と加算され、加算された舵角制御指令値Imref2がリミッタ203でリミット処理され、舵角制御指令値Imrefが出力される(ステップS214)。舵角制御指令値Imrefは乗算部142-1において舵角制御出力徐変ゲインSWG1で徐変され(ステップS215)、徐変された舵角制御指令値Imrefgは加算部142-3に入力される。
The steering angular speed control unit 220 calculates a speed deviation Df, calculates the integral-compensated steering angle control current value Ir1 and the proportionally compensated steering angle control current value Ir2 as described above, and performs speed control as a deviation thereof. The current value Imref0 is calculated (step S212). The speed control current value Imref0 is gradually changed by the multiplication unit 224 by the speed control gradual change gain SG2, the gradually changed speed control current value Imref1 is output, and the speed control current value Imref1 is input to the addition unit 204 (step S213). ). Further, a vibration suppression process based on the steering torque Th is performed, and the vibration suppression signal Thd after the vibration suppression process is added to the speed control current value Imref1 by the adding unit 204, and the added steering angle control command value Imref2 is the limiter 203. The limit process is performed, and the steering angle control command value Imref is output (step S214). The steering angle control command value Imref is gradually changed by the steering angle control output gradually changing gain SWG1 in the multiplying unit 142-1 (step S215), and the gradually changed steering angle control command value Imrefg is input to the adding unit 142-3. .
切換部142にはアシスト制御出力徐変ゲインSWG2が入力されており、アシスト制御出力徐変ゲインSWG2を前回値から減算(演算初回の前回値=100%)し(ステップS220)、アシスト制御出力徐変ゲインSWG2が0%以下の場合は、0%に制限する(ステップS221、S222)。アシスト制御指令値Itrefを演算すると共に、乗算部142-2においてアシスト制御出力徐変ゲインSWG2で徐変し、アシスト制御指令値Itrefgを出力する(ステップS223)。
The assist control output gradual change gain SWG2 is input to the switching unit 142, and the assist control output gradual change gain SWG2 is subtracted from the previous value (previous value of the first calculation = 100%) (step S220). When the variable gain SWG2 is 0% or less, the variable gain SWG2 is limited to 0% (steps S221 and S222). While calculating the assist control command value Itref, the multiplier 142-2 gradually changes the assist control output value Itrefg gain SWG2, and outputs the assist control command value Itrefg (step S223).
その後、徐変されたアシスト制御指令値Itrefgが加算部142-3に入力され、舵角制御指令値Imrefgと加算されてモータ電流指令値Irefが演算される(ステップS224)。モータ電流指令値Irefによりモータが駆動される。そして、舵角制御出力徐変ゲインSWG1の前回値を舵角制御出力徐変ゲインSWG1に更新し、アシスト制御出力徐変ゲインSWG2の前回値をアシスト制御出力徐変ゲインSWG2に更新すると共に、速度指令徐変ゲインSG1の前回値を速度指令徐変ゲインSG1に更新し、速度制御徐変ゲインSG2の前回値を速度指令徐変ゲインSG2に更新し、更にリミッタ202のリミッタ制限値の前回値をリミッタ制限値に更新する(ステップS225)。速度指令徐変ゲインSG1及び速度制御徐変ゲインSG2についても同様に、前回値を更新する。
Thereafter, the gradually changed assist control command value Itrefg is input to the adder 142-3 and added to the steering angle control command value Imrefg to calculate the motor current command value Iref (step S224). The motor is driven by the motor current command value Iref. Then, the previous value of the steering angle control output gradual change gain SWG1 is updated to the steering angle control output gradual change gain SWG1, the previous value of the assist control output gradual change gain SWG2 is updated to the assist control output gradual change gain SWG2, and the speed is increased. The previous value of the command gradual change gain SG1 is updated to the speed command gradual change gain SG1, the previous value of the speed control gradual change gain SG2 is updated to the speed command gradual change gain SG2, and the previous value of the limiter limit value of the limiter 202 is further updated. The limiter limit value is updated (step S225). Similarly, the previous value is updated for the speed command gradual change gain SG1 and the speed control gradual change gain SG2.
図24及び図25は、リミッタ202後の目標舵角速度ωcb、舵角制御出力徐変ゲインSWG1、アシスト制御出力徐変ゲインSWG2及びリミッタ202の制限値1、制限値2の関係を示すタイムチャートである。図15の例では、舵角制御状態でのアシスト制御出力徐変ゲインSWG2を50%として説明しているが、図24及び図25では0%として説明する。図24の例では、時点t0でアシスト制御から舵角制御に移行し、時点t3に完全に舵角制御になる様子を示している。リミッタ202の制限値は、完全に舵角制御になる時点t3より少し前の時点t2(閾値により設定)から、時点t3以降の時点t4の間に制限値1から制限値2(>制限値1)に徐々に変わるようになっている。図25の例も、時点t10でアシスト制御から舵角制御に移行し、時点t12に完全に舵角制御になる様子を示している。本例では、リミッタ202の制限値は、完全に舵角制御になった時点12から以降時点t13の間に、制限値1から制限値2に変わるようになっている。
24 and 25 are time charts showing the relationship among the target steering angular velocity ωcb, the steering angle control output gradual change gain SWG1, the assist control output gradual change gain SWG2 and the limit value 1 and limit value 2 of the limiter 202 after the limiter 202. FIG. is there. In the example of FIG. 15, the assist control output gradual change gain SWG2 in the steering angle control state is described as 50%, but in FIG. 24 and FIG. In the example of FIG. 24, a state is shown in which the shift from the assist control to the steering angle control is performed at time t0 and the steering angle control is completely performed at time t3. The limit value of the limiter 202 is from the limit value 1 to the limit value 2 (> limit value 1) between the time point t2 (set by the threshold) slightly before the time point t3 when the steering angle control is completely performed and the time point t4 after the time point t3. ) Gradually change. The example of FIG. 25 also shows a state where the assist control is shifted to the steering angle control at time t10 and the steering angle control is completely performed at time t12. In this example, the limit value of the limiter 202 is changed from the limit value 1 to the limit value 2 between the time point 12 when the steering angle control is completely performed and the time point t13 thereafter.
図24(B)及び(C)の時点t0~t3に示すように、また、図25(B)及び(C)の時点t10~t12に示すように、舵角制御出力徐変ゲインSWG1とアシスト制御出力徐変ゲインSWG2はその割合の合計値が原則的に1.0(100%)の関係で、かつ逆の関係で増加減するようになっている。増加減の波形(特性)は任意であり、線形であっても、非線形であっても良い。
As shown at times t0 to t3 in FIGS. 24B and 24C and at times t10 to t12 in FIGS. 25B and 25C, the steering angle control output gradual change gain SWG1 and the assist The control output gradual change gain SWG2 is configured so that the total value of the ratios increases and decreases in a relationship of 1.0 (100%) in principle and in an opposite relationship. The increase / decrease waveform (characteristic) is arbitrary, and may be linear or non-linear.
舵角制御開始時(アシスト制御からの切換時)は、位置制御部210の出力の舵角速度指令値ωcに対して速度指令徐変ゲインSG1を乗じる。この徐変ゲインSG1は、舵角制御指令値Imrefに乗じる舵角制御出力徐変ゲインSWG1と同期している(完全に同期でなくても良い)。加えて、速度指令徐変ゲインSG1の乗算後の舵角速度指令値ωcaに対して上下限可変のリミッタ202を設けている。このリミッタ202は舵角速度指令値ωcaの制限値を逐次切換え可能で、この制限値を徐変ゲインSG1が設定閾値未満では小さい値で固定し、閾値以上で徐々に大きくすることにより、舵角速度指令値ωcaが制限され、目標舵角速度ωcbとして舵角速度制御部220に入力される。さらに、速度制御部220内の信号に速度制御徐変ゲインSG2(SG1と同期でも良い)を乗じる。結果的に、舵角速度制御部220内の積分値の過剰な蓄積を抑制し、運転者への違和感を生じる舵角制御出力としての電流指令値を低減する。また、徐変完了後は、速度指令徐変ゲインSG1と上下限可変リミッタ202により舵角速度指令値ωcaが制限されず、速度制御徐変ゲインSG2により舵角速度制御部220内の信号が制限されないため、通常の舵角制御にシフトすることができる。ただし、本実施形態では、速度制御徐変ゲインSG2、速度指令徐変ゲインSG1は図24及び図25には表示せず、舵角制御出力徐変ゲインSWG1と一致させている。また、舵角制御モードへの切換時の初回の演算で、舵角指令値のレートリミッタの過去値Z-1の値を検出した実操舵角で上書きする。これにより、切換時にハンドル振動除去部430の段後の目標舵角θtと実舵角θrがほぼ一致することで、舵角制御電流指令値の発生を抑え、結果的にハンドルの急変動を防止する。
When the steering angle control is started (at the time of switching from the assist control), the speed command gradual change gain SG1 is multiplied to the steering angular speed command value ωc output from the position control unit 210. This gradual change gain SG1 is synchronized with the steering angle control output gradual change gain SWG1 multiplied by the steering angle control command value Imref (not necessarily completely synchronized). In addition, a limiter 202 having a variable upper and lower limit is provided for the steering angular speed command value ωca after multiplication by the speed command gradual change gain SG1. The limiter 202 can sequentially switch the limit value of the steering angular velocity command value ωca, and this limit value is fixed to a small value when the gradual change gain SG1 is less than the set threshold value, and gradually increased above the threshold value. The value ωca is limited and is input to the steering angular velocity control unit 220 as the target steering angular velocity ωcb. Further, the signal in the speed control unit 220 is multiplied by a speed control gradually changing gain SG2 (which may be synchronized with SG1). As a result, excessive accumulation of the integral value in the rudder angular velocity control unit 220 is suppressed, and the current command value as the rudder angle control output that causes discomfort to the driver is reduced. Further, after completion of the gradual change, the steering angle speed command value ωca is not limited by the speed command gradual change gain SG1 and the upper / lower limit variable limiter 202, and the signal in the steering angular speed control unit 220 is not limited by the speed control gradual change gain SG2. Shift to normal steering angle control. However, in this embodiment, the speed control gradual change gain SG2 and the speed command gradual change gain SG1 are not displayed in FIGS. 24 and 25, and are made to coincide with the steering angle control output gradual change gain SWG1. In the first calculation at the time of switching to the steering angle control mode, the value of the past value Z −1 of the rate limiter of the steering angle command value is overwritten with the detected actual steering angle. Accordingly, the target steering angle θt after the step of the steering wheel vibration removing unit 430 and the actual steering angle θr substantially coincide with each other at the time of switching, thereby suppressing the generation of the steering angle control current command value and consequently preventing the steering wheel from changing suddenly. To do.
本発明では、手入力判定部410の入力部にLPF411(1次フィルタでカットオフ周波数2Hz)を用いると共に、操舵トルクThの絶対値|Tha|を求める絶対値部412を備え、操舵トルクThの絶対値|Tha|をトルク閾値Tthと比較し、更に積分値を積分閾値Sthと比較しており、これらの要素に基づく効果を以下に説明する。
In the present invention, an LPF 411 (a cutoff frequency of 2 Hz with a primary filter) is used as an input unit of the manual input determination unit 410, and an absolute value unit 412 for obtaining an absolute value | Tha | of the steering torque Th is provided. The absolute value | Tha | is compared with the torque threshold value Tth, and the integral value is further compared with the integral threshold value Sth. The effects based on these elements will be described below.
図26は模式的に示したものであり、特許文献3で示されるように、絶対値とトルク閾値のみで手入力を判定する場合の問題を示しており、悪路などを走行中に過渡的な大きな路面外乱の影響により、コラム軸周りに図26(A)に示すような外乱トルクTdが発生する。路面外乱(外乱トルク)の影響により、操舵トルク(トーションバートルク)にその外乱成分が乗ってしまい、図26(B)に示すように、一瞬でもトルク閾値以上になると、手入力「有り」の判定になってしまう問題がある。つまり、路面外乱の影響を受け易く、誤判定し易い機能である。
FIG. 26 schematically shows a problem in the case where manual input is determined only by an absolute value and a torque threshold as shown in Patent Document 3, and is transient during traveling on a rough road or the like. Due to the influence of a large road disturbance, a disturbance torque Td as shown in FIG. 26A is generated around the column axis. Due to the influence of the road surface disturbance (disturbance torque), the disturbance component is added to the steering torque (torsion bar torque), and as shown in FIG. There is a problem that becomes a judgment. That is, it is a function that is easily affected by road surface disturbances and is easily misjudged.
また、絶対値を用いないで、特許文献4で示されるようにトルク閾値と積分閾値のみで手入力を判定する場合には、図27(A)に示すように操舵トルクThに対して正負のトルク閾値を設定する必要があると共に、図27(B)に示すように積分出力値Ioutに対して正負の積分閾値を設定する必要がある。本発明のように操舵トルクThの絶対値|Tha|を求め、絶対値|Tha|をトルク閾値Tthと比較し、更に積分出力値を積分閾値Sthと比較することにより、図28(A)に示すように路面外乱が発生し、トルク閾値Tthを超えた場合においても、トルクに対する積分出力値Ioutは積分閾値Sthに到達しない。つまり、本発明は路面外乱の影響を受け難く、誤判定を起こし難い利点がある。
Further, when manual input is determined only by the torque threshold value and the integral threshold value as shown in Patent Document 4 without using an absolute value, it is positive or negative with respect to the steering torque Th as shown in FIG. It is necessary to set a torque threshold value, and it is necessary to set a positive / negative integral threshold value with respect to the integral output value Iout as shown in FIG. As in the present invention, the absolute value | Tha | of the steering torque Th is obtained, the absolute value | Tha | is compared with the torque threshold value Tth, and the integral output value is compared with the integral threshold value Sth. As shown, even when a road surface disturbance occurs and the torque threshold value Tth is exceeded, the integrated output value Iout for the torque does not reach the integration threshold value Sth. In other words, the present invention is advantageous in that it is less susceptible to road surface disturbances and is less prone to erroneous determination.
図29は本発明が特許文献4に示される装置よりも優れていることを示しており、本発明では図29(A)に示すように操舵トルクThに対して1個のトルク閾値Tthを設定すれば良く、絶対値化しない場合と比べ、分岐処理を簡略化できる。また、積分演算部415の入力は絶対値であるため、操舵トルクThが負(細線)であっても、図29(B)に示すように積分出力値Ioutは必ず0以上の値となり、積分出力値Ioutに対して1個の積分閾値Sthを設定すれば良い。絶対値化しない場合と比べ、分岐処理を簡略化できる利点がある。本発明の絶対値化はトルク値比較部413の前段であることで、トルク閾値Tth及び積分閾値Sthはそれぞれ1個で良くなる。
FIG. 29 shows that the present invention is superior to the apparatus disclosed in Patent Document 4, and in the present invention, one torque threshold value Tth is set for the steering torque Th as shown in FIG. 29 (A). The branching process can be simplified as compared with the case where the absolute value is not used. Further, since the input of the integral calculation unit 415 is an absolute value, even if the steering torque Th is negative (thin line), the integral output value Iout is always 0 or more as shown in FIG. One integration threshold value Sth may be set for the output value Iout. There is an advantage that the branch process can be simplified as compared with the case where the absolute value is not used. Since the absolute value conversion according to the present invention is performed before the torque value comparison unit 413, only one torque threshold value Tth and one integration threshold value Sth are required.
シミュレーションの図30に示すように、舵角制御中に舵角指令値が発生した場合の操舵トルクThに対して外乱トルクTd(コラム軸のトルク換算)を入力した場合、トーションバー検出トルク(操舵トルクTh)は図31(シミュレーション)の太線に示すようになり、LPF411を経た操舵トルクThaは図31の細線のように振幅幅が減衰される。図31には、積分(積算)演算を実行する条件に使用されるトルク閾値Tthも示されている。そして、図31のLPF411の有無に対応する信号を積分演算部415で同一の時間軸で積分した結果を、シミュレーションの図29に示す。図32の細線はLPF無しの操舵トルクTh(絶対値)の積算値で、太線はLPF後(絶対値)の積算値である。積算演算は、演算周期0.001[s]と操舵トルクTh(絶対値)を乗算したものを前回値に加算しており、積分閾値Sthは3.5[Nm]と設定した。外乱トルクTdの影響で操舵トルクThが変動し、操舵トルクTh(Tha)の絶対値が、トルク閾値Tthを下回ることで積算値が0にリセットされ積算閾値Sthに到達するまでに遅れが発生している。結果的に、LPF411を介挿したものの方が、外乱トルクTdの影響を緩和し、積分閾値Sthに早く到達し、手入力判定が速くされている。
As shown in FIG. 30 of the simulation, when the disturbance torque Td (column shaft torque conversion) is input to the steering torque Th when the steering angle command value is generated during the steering angle control, the torsion bar detected torque (steering Torque Th) is indicated by a thick line in FIG. 31 (simulation), and the steering torque Tha that has passed through the LPF 411 is attenuated in amplitude as shown by a thin line in FIG. FIG. 31 also shows a torque threshold Tth used as a condition for executing the integration (integration) calculation. FIG. 29 is a simulation result of integrating signals corresponding to the presence / absence of the LPF 411 in FIG. 31 by the integration calculation unit 415 on the same time axis. The thin line in FIG. 32 is the integrated value of the steering torque Th (absolute value) without LPF, and the thick line is the integrated value after LPF (absolute value). In the integration calculation, a value obtained by multiplying the calculation cycle 0.001 [s] and the steering torque Th (absolute value) is added to the previous value, and the integration threshold Sth is set to 3.5 [Nm]. The steering torque Th fluctuates due to the disturbance torque Td, and when the absolute value of the steering torque Th (Tha) falls below the torque threshold value Tth, the integrated value is reset to 0 and a delay occurs until the integrated threshold value Sth is reached. ing. As a result, the LPF 411 inserted reduces the influence of the disturbance torque Td, reaches the integral threshold value Sth earlier, and speeds up manual input determination.
操舵トルクThの絶対値が一時的なメモリ異常などにより、異常な過大値となった場合に、異常な過大値の積分入力値Ioutを積分演算し、積分出力値Ioutが積分閾値Sthを超えて誤判定を起こす場合がある。そこで、本発明では積分入力値Cta前にリミッタ414を設けることによって、操舵トルクThの絶対値が異常な過大値となった場合でも、積分出力値Ioutが積分閾値Sthを超えず、手入力の誤判定を防ぐようにしている。リミッタ無しの場合、模式的に示す図33に示すように、操舵トルクThの絶対値|Tha|がトルク閾値Tthより小さい場合においては、積分値は0にリセット処理され続けるため、積分出力値Ioutは0である。当然、積分出力値Ioutは積分閾値Sthより小さいため、手入力「無し」の判定となる。しかし、メモリ異常などにより、図33(A)のように操舵トルクThの絶対値|Tha|が異常に過大な値となった場合にトルク閾値Tthを超え、異常に過大な値に対して積分演算を実施する。このため、図33(C)のように積分出力値Ioutが積分閾値Sthを超え、手入力「有り」の判定となってしまう。
When the absolute value of the steering torque Th becomes an abnormal excessive value due to a temporary memory abnormality or the like, the integral input value Iout of the abnormal excessive value is integrated and the integrated output value Iout exceeds the integration threshold value Sth. An erroneous determination may occur. Therefore, in the present invention, by providing the limiter 414 before the integral input value Cta, even if the absolute value of the steering torque Th becomes an abnormal excessive value, the integral output value Iout does not exceed the integral threshold value Sth, and the manually input value The misjudgment is prevented. When there is no limiter, as shown schematically in FIG. 33, when the absolute value | Tha | of the steering torque Th is smaller than the torque threshold value Tth, the integral value continues to be reset to 0, so that the integral output value Iout Is 0. Naturally, since the integral output value Iout is smaller than the integral threshold value Sth, it is determined that there is no manual input. However, when the absolute value | Tha | of the steering torque Th becomes an abnormally large value as shown in FIG. 33A due to a memory abnormality or the like, the torque threshold value Tth is exceeded and integration is performed for the abnormally excessive value. Perform the operation. For this reason, as shown in FIG. 33C, the integrated output value Iout exceeds the integration threshold value Sth, and it is determined that the manual input is “present”.
これに対し、リミッタ有りの場合、模式的に示す図34に示すように操舵トルクThの絶対値|Tha|が異常に過大な値となった場合にトルク閾値を超え(図34(A))、異常に過大な値に対して積分演算を実施する。しかし、リミッタ414で図34(B)に示すように積分入力値Ctaを制限することにより、異常に過大な値に対して積分演算を行わなくて済む。このため、図34(C)に示すように積分出力値Ioutが過大な値とならなくなり、手入力の誤判定を防ぐことが可能となる。
On the other hand, when there is a limiter, the torque threshold is exceeded when the absolute value | Tha | of the steering torque Th is abnormally excessive as shown in FIG. 34 schematically (FIG. 34A). Execute integration calculation for abnormally large values. However, by limiting the integral input value Cta with the limiter 414 as shown in FIG. 34 (B), it is not necessary to perform an integral operation on an abnormally large value. For this reason, as shown in FIG. 34C, the integral output value Iout does not become an excessive value, and it is possible to prevent an erroneous determination of manual input.
また、上述では対象を速度制御としているが、要求舵角などの入力を蓄積し、電流指令値などの出力へ利用する構成を持つ制御方式に対しても有効であり、位置制御及び速度制御に前記機能が組み込まれていれば、その他の構成は適宜変更可能である。更に、実舵角速度はモータ速度と減速比から求めても良く、ハンドル舵角センサから求めても良い。
Although the target is speed control in the above, it is also effective for a control system having a configuration in which input such as a required steering angle is accumulated and used for output such as a current command value, for position control and speed control. If the function is incorporated, other configurations can be changed as appropriate. Furthermore, the actual steering angular speed may be obtained from the motor speed and the reduction ratio, or may be obtained from a steering wheel steering angle sensor.
上述では前処理部と舵角制御部を分けた構成としているが、舵角制御部内に前処理部を含むようにしても良い。図10、図12、図15、図17、図24~図29、図33、図34はいずれも模式図であり、分かり易く説明するための図である。
In the above description, the pre-processing unit and the rudder angle control unit are separated, but the pre-processing unit may be included in the rudder angle control unit. 10, FIG. 12, FIG. 15, FIG. 17, FIG. 24 to FIG. 29, FIG. 33, and FIG. 34 are all schematic views and are diagrams for easy understanding.
1 ハンドル(ステアリングホイール)
2 コラム軸(ステアリングシャフト、ハンドル軸)
10 トルクセンサ
20、150 モータ
30 コントロールユニット(ECU)
31 電流指令値演算部
130 車両側ECU
140 EPS側ECU
141 アシスト制御部
142 切換部
200 舵角制御部
202 リミッタ
210、210A 位置制御部
220 舵角速度制御部
400 切換判定/徐変ゲイン生成部
410 手入力判定部
420 徐変ゲイン切換生成部
440 ハンドル制振部
500、500A 前処理部 1 Handle (steering wheel)
2 Column shaft (steering shaft, handle shaft)
10 Torque sensor 20, 150 Motor 30 Control unit (ECU)
31 Current commandvalue calculation unit 130 Vehicle side ECU
140 EPS side ECU
141Assist control unit 142 Switching unit 200 Steering angle control unit 202 Limiters 210 and 210A Position control unit 220 Steering angular velocity control unit 400 Switching determination / gradual change gain generation unit 410 Manual input determination unit 420 Gradual change gain switching generation unit 440 Handle damping 500, 500A pre-processing unit
2 コラム軸(ステアリングシャフト、ハンドル軸)
10 トルクセンサ
20、150 モータ
30 コントロールユニット(ECU)
31 電流指令値演算部
130 車両側ECU
140 EPS側ECU
141 アシスト制御部
142 切換部
200 舵角制御部
202 リミッタ
210、210A 位置制御部
220 舵角速度制御部
400 切換判定/徐変ゲイン生成部
410 手入力判定部
420 徐変ゲイン切換生成部
440 ハンドル制振部
500、500A 前処理部 1 Handle (steering wheel)
2 Column shaft (steering shaft, handle shaft)
10
31 Current command
140 EPS side ECU
141
Claims (9)
- アシスト制御モードと舵角制御モードを切換指令により切り換える機能を有し、アシスト制御部で演算された第1のアシスト制御指令値と、舵角制御部で演算された第1の舵角制御指令値とでモータ電流指令値を生成し、前記モータ電流指令値によりモータを駆動して車両の操舵系をアシスト制御する電動パワーステアリング装置において、
操舵トルク及び前記切換指令に基づいて、舵角制御の位置速度制御で用いる速度指令徐変ゲイン及び速度制御徐変ゲインと、制御モードの切換時に用いる舵角制御出力徐変ゲイン及びアシスト制御出力徐変ゲインとを生成する切換判定/徐変ゲイン生成部を備え、
前記舵角制御部は、
舵角指令値を目標舵角として入力し、前記目標舵角及び実舵角の角度偏差に基づいて舵角速度指令値を出力する位置制御部と、前記舵角速度指令値を前記速度指令徐変ゲインに応じて徐変すると共に、上下限値を制限して出力する徐変制限部と、前記徐変制限部から出力される目標舵角速度を、実舵角速度及び前記速度徐変ゲインに基づいて処理する舵角速度制御部と、前記舵角速度制御部から出力される速度制御電流値を前記舵角制御出力徐変ゲインで徐変して第2の舵角制御指令値を出力する第1の徐変出力部とで構成され、
前記アシスト制御部から出力される前記第1のアシスト制御指令値を前記アシスト制御出力徐変ゲインで徐変し、第2のアシスト制御指令値を出力する第2の徐変出力部を備え、
前記第2の舵角制御指令値及び前記第2のアシスト制御指令値に基づいて前記モータ電流指令値を生成し、
前記切換判定/徐変ゲイン生成部は手入力判定部を有し、
前記手入力判定部は、前記操舵トルクをフィルタ処理するLPFと、前記LPFを経た操舵トルクの絶対値をトルク閾値と比較すると共に、出力信号として出力するトルク値比較部と、前記出力信号の全体を積分して前記積分出力値を出力する積分演算部と、前記積分演算部からの前記積分出力値と積分閾値を比較することにより、操舵トルク判定信号を出力する切換判定部とで構成されている、
ことを特徴とする電動パワーステアリング装置。 The first assist control command value calculated by the assist control unit and the first steering angle control command value calculated by the steering angle control unit have a function of switching between the assist control mode and the steering angle control mode by a switching command. And an electric power steering device that generates a motor current command value and drives the motor with the motor current command value to assist control a vehicle steering system.
Based on the steering torque and the switching command, the speed command gradual change gain and speed control gradual gain used in the steering speed control position / speed control, the steering angle control output gradual change gain and assist control output gradual gain used when switching the control mode. A switching determination / gradual gain generating unit for generating variable gain,
The rudder angle control unit
A position control unit that inputs a rudder angle command value as a target rudder angle and outputs a rudder angular velocity command value based on an angle deviation between the target rudder angle and the actual rudder angle, and the rudder angular velocity command value as the speed command gradual gain A gradual change limiting unit that outputs a gradual change in accordance with the upper and lower limit values, and a target rudder angular velocity output from the gradual change restriction unit, based on an actual rudder angular velocity and the speed gradual change gain And a first gradual change that outputs a second rudder angle control command value by gradually changing the speed control current value output from the rudder angular speed control unit by the rudder angle control output gradual change gain. It consists of an output part,
A second gradual change output unit that gradually changes the first assist control command value output from the assist control unit with the assist control output gradual change gain, and outputs a second assist control command value;
Generating the motor current command value based on the second steering angle control command value and the second assist control command value;
The switching determination / gradual change gain generation unit has a manual input determination unit,
The manual input determination unit compares an LPF for filtering the steering torque, a torque value comparison unit that compares the absolute value of the steering torque that has passed through the LPF with a torque threshold value, and outputs the output signal, and the entire output signal. And a switching determination unit that outputs a steering torque determination signal by comparing the integration output value from the integration calculation unit with an integration threshold value. Yes,
An electric power steering device. - 前記位置制御部が、
前記目標舵角及び前記実舵角の角度偏差1を求める第1の減算部と、前記角度偏差1を比例処理して前記舵角速度指令値を出力する第1の比例部とで構成されている請求項1に記載の電動パワーステアリング装置。 The position controller is
A first subtraction unit that obtains an angle deviation 1 between the target rudder angle and the actual rudder angle, and a first proportional unit that proportionally processes the angle deviation 1 and outputs the rudder angular velocity command value. The electric power steering apparatus according to claim 1. - 前記位置制御部が、
前記目標舵角に含まれるハンドル振動周波数成分を除去するハンドル振動除去部と、前記ハンドル振動除去部からの舵角信号1及び前記実舵角の角度偏差2を求める第2の減算部と、前記角度偏差2を比例処理して角度偏差3を求める第2の比例部と、前記目標舵角の振動成分を低減するフィードフォワード(FF)フィルタと、前記角度偏差3及び前記FFフィルタからの舵角信号2を加算して前記舵角速度指令値を出力する加算部とで構成されている請求項1に記載の電動パワーステアリング装置。 The position controller is
A steering wheel vibration removing unit that removes a steering wheel vibration frequency component included in the target steering angle; a second subtracting unit that obtains a steering angle signal 1 from the steering wheel vibration removing unit and an angular deviation 2 of the actual steering angle; A second proportional unit for proportionally processing the angular deviation 2 to obtain the angular deviation 3, a feed forward (FF) filter for reducing the vibration component of the target steering angle, and the steering angle from the angular deviation 3 and the FF filter The electric power steering apparatus according to claim 1, further comprising an addition unit that adds the signal 2 and outputs the steering angular velocity command value. - 前記操舵トルクのハンドル制振を行うハンドル制振部が設けられ、前記ハンドル制振部からの制振信号を前記速度制御電流値に加算するようになっている請求項1乃至3のいずれかに記載の電動パワーステアリング装置。 4. A steering wheel damping unit that performs steering damping of the steering torque is provided, and a damping signal from the steering wheel damping unit is added to the speed control current value. The electric power steering apparatus as described.
- 前記舵角指令値を前記目標舵角に変換する前処理部が設けられており、前記前処理部は、前記舵角指令値の上下限値を制限するリミッタと、前記リミッタの出力を円滑化するレートリミッタと、前記レートリミッタの出力からハンドル振動を除去するハンドル振動除去部とで構成されている請求項1、2又は4に記載の電動パワーステアリング装置。 A pre-processing unit that converts the rudder angle command value into the target rudder angle is provided, and the pre-processing unit smoothes the limiter that limits the upper and lower limit values of the rudder angle command value, and the output of the limiter 5. The electric power steering apparatus according to claim 1, further comprising: a rate limiter that performs the operation and a handle vibration removal unit that removes the handle vibration from the output of the rate limiter.
- 前記舵角指令値を前記目標舵角に変換する前処理部が設けられており、前記前処理部は、前記舵角指令値の上下限値を制限するリミッタと、前記リミッタの出力を円滑化するレートリミッタとで構成されている請求項1、3又は4に記載の電動パワーステアリング装置。 A pre-processing unit that converts the rudder angle command value into the target rudder angle is provided, and the pre-processing unit smoothes the limiter that limits the upper and lower limit values of the rudder angle command value, and the output of the limiter The electric power steering device according to claim 1, 3, or 4, wherein the electric power steering device is configured with a rate limiter.
- 前記徐変制限部の前記上下限値が、前記速度指令徐変ゲインに応じて可変される請求項1乃至6のいずれかに記載の電動パワーステアリング装置。 The electric power steering apparatus according to any one of claims 1 to 6, wherein the upper and lower limit values of the gradual change limiting unit are varied in accordance with the speed command gradual change gain.
- 前記積分出力値は、前記舵角制御モード中で、かつ、前記絶対値に変換した前記操舵トルクが前記トルク閾値に達した時に積算を開始し、前記積分出力値が前記積分閾値に達した時に、前記舵角制御モードを前記舵角制御モードに切り換える請求項1乃至7のいずれかに記載の電動パワーステアリング装置。 The integral output value starts integration when the steering torque is converted into the absolute value during the steering angle control mode and the torque output reaches the torque threshold, and when the integral output value reaches the integration threshold. The electric power steering apparatus according to any one of claims 1 to 7, wherein the steering angle control mode is switched to the steering angle control mode.
- 前記トルク値比較部が、前記舵角制御モード中で、かつ、前記操舵トルクが前記トルク閾値よりも小さいときに、前記積分演算部を初期化する過去値初期化信号を出力する機能を具備している請求項1乃至8のいずれかに記載の電動パワーステアリング装置。 The torque value comparison unit has a function of outputting a past value initialization signal for initializing the integral calculation unit when the steering angle control mode is in progress and the steering torque is smaller than the torque threshold value. The electric power steering device according to any one of claims 1 to 8.
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WO2014119359A1 (en) * | 2013-01-29 | 2014-08-07 | 日本精工株式会社 | Electric power steering device |
JP2014155358A (en) * | 2013-02-12 | 2014-08-25 | Mitsubishi Electric Corp | Controller for electrically-driven supercharger |
WO2014136515A1 (en) * | 2013-03-08 | 2014-09-12 | 日本精工株式会社 | Electric power steering device |
WO2014162769A1 (en) * | 2013-04-04 | 2014-10-09 | 日本精工株式会社 | Electric power steering device |
JP2015145167A (en) * | 2014-02-03 | 2015-08-13 | 日立建機株式会社 | Hybrid construction machine |
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JP2014155358A (en) * | 2013-02-12 | 2014-08-25 | Mitsubishi Electric Corp | Controller for electrically-driven supercharger |
WO2014136515A1 (en) * | 2013-03-08 | 2014-09-12 | 日本精工株式会社 | Electric power steering device |
WO2014162769A1 (en) * | 2013-04-04 | 2014-10-09 | 日本精工株式会社 | Electric power steering device |
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