CN101147041A - Signal processing and position determining apparatus and methods - Google Patents

Abstract

Signal processing apparatus, e.g. a resolver-to-digital converter (30), converts an analogue input, e.g. sinusoidal signals such as resolver signals Vsin,Vcos, into a digital output, e.g. an angular position and angular speed for a rotor. A first processing unit (31), e.g. a quadrature encoder, monitors the input at a first resolution to produce a first tracking error e1 between the digital output and the analogue input, and a second processing unit (32), which e.g. samples the input signals and e.g. applies a sine cosine function or an arctan function, monitors the input at a second resolution higher than the first resolution to produce a second tracking error e2 between the digital output and analogue input. The apparatus determines the digital output based on the first or second tracking error, e.g. through processing with a filter (33), and includes a switch (34) for switching between the two errors so as to promote tracking stability. Switching may for example be based on a comparison of the first error signal e1 with a threshold value, e.g. a maximum error value.

Description

Signal Processing and position determining means and method

Present patent application requires the right of priority at the temporary patent application No.2005901050 of Australia's submission on March 4th, 2005, and its full content is incorporated among the application by reference at this.

The present invention relates to the apparatus and method when determining the position of monitored target, used.It is applied to the angular coordinate and/or the speed of the rotor of detection axis for example such as motor, but its also has widely and uses.The present invention can be particularly useful in automotive control system, is included in line control system such as the application in the line control brake system.

When using motor as drive unit in control system, when for example coming the clamp of drive wheels brake, the feedback that obtains relevant motor rotor position and/or speed during driving is important, so that can accurate accessory drive.

Generally, use solver (resolver) to monitor rotor-position.Solver self has the rotor of the rotor coupling that is used for and is monitored, and this internal rotor has coil.Solver also comprises a pair of fixedly quadrature coil that contiguous solver rotor is installed, and this is coupled to export sine and cosine signal respectively when rotor winding rotates to coil and solver rotor winding.Because sinusoidal signal and cosine signal are out-phase, so can determine rotor angle in time utterly at any point to the measurement of both amplitudes.

Target of the present invention is to provide signal Processing and the position determining means and the method for novelty, and its various embodiment provide many advantages, and for example can be in conjunction with uses such as solvers so that digital position signal to be provided.

From on the one hand, the invention provides the analog input that is used for indication monitored target position and convert the signal processing apparatus that numeral is exported to, this numeral output tracking is somebody's turn to do input, and the processing unit that this device comprises is used for:

Monitor described input to produce first tracking error between described numeral output and the described input according to first resolution;

Monitor described input to produce second tracking error between described numeral output and the described input by second resolution that is higher than described first resolution; And

Determine described numeral output based on described first or second tracking error, described processing unit switches between the use that is used to provide described digital described first and second tracking errors of exporting and switches, thereby improves tracking stability.

Therefore, an embodiment of the invention can provide the converter that the simulation output of solver is converted to digital angular position and velocity amplitude.These values can be used to FEEDBACK CONTROL or monitoring purpose then.Yet, the invention is not restricted to these systems, can under many other situations, use.

Converter provided by the invention can keep stable when high-speed and high acceleration, and very accurate.

Can repeatedly sample to input and obtain second error signal in each cycle, to extract high-resolution position signalling.Yet, device is also followed the tracks of output digital signal dispersing with respect to input signal, when this dispersed too high the non-steady state of angle losing lock (as trend towards), device can switch to first error signal, and it has low resolution and the more discrete output of not allowing to be subject to the losing lock influence is provided.

For example, high rotor speed or acceleration that locking may can not be handled because of the high resolving power sampling thief of solver or converter part, and/or lose because of reasons such as noise, temperature drift, phase shift or amplitude are inhomogeneous.

In these cases, device can use the low resolution signal stable up to situation, follows the tracks of thereby allow device to switch back high resolving power.

Input is preferably sinusoidal input, and sinusoidal signal and the cosine signal that is provided by solver by for example be provided.Yet the present invention also can be used for changing other inputs, as single sinusoidal signal or two above signals, or the signal (as not being 90 degree, for example 0 to 180 spends) with out of phase relation.For example, if use synchrodyne to come objective for implementation position probing (this synchrodyne is similar to solver, but uses 3 coils (winding)), device can receive 3 sinusoidal signals then, and each signal is another skew 120 degree relatively.The present invention also can use together with alternative signal generator, for example multipole solver, scrambler (as optical encoder) or inductosyn ^TMTransducer.The latter provides the signal type identical with solver, but direct detection linear movement, and use the scale of the energising that makes by printed circuit traces and the slider that moves along this scale with regular waveform patterns, and comprise parallel and have a pair of printed circuit traces of same pitch, but slider trace another skew 1/4th pitches relatively with this scale pattern.

Processing unit can comprise the regulon that is used to regulate input signal, so that the square wave input for example to be provided, is used for determining first tracking error.This for example can comprise the Schmidt trigger at each input signal.Regulate, for example use of square wave can make things convenient for the thick of status input signal to determine, the robustness at noise etc. is provided simultaneously.

Because processing unit is only monitored simulating signal under the low resolution that is used for first tracking signal, its may be for example only measuring period that object moves specific half, the state of four/first-class identification input, for example the angle that becomes of rotor is in which quadrant in four quadrants of sinusoidal period.Processing unit can for example be monitored zero crossing or the rising and/or the negative edge of the ripple through overregulating (for example square wave) of position that is used for determining monitored target of (as counting) input.

In a particularly preferred embodiment, processing unit comprises orthogonal encoder.Orthogonal encoder is determined in four positions of monitored target based on a pair of square waves of separating 90 degree on phase place.Scrambler determines that two ripples " 1 " or " 0 " state determine which of repetition period four positions object be arranged in, and for example rotor is positioned at which 90 degree sector of rotation.

Orthogonal encoder is the measurement form of special robust, and it can give stability to whole tracking converter, otherwise converter may losing lock.

For first error signal is provided, the numeral output of the device output from orthogonal encoder can be deducted.

In one embodiment, processing unit uses high resolving power monitoring analog input by determining object's position based on arctan function.Therefore, can do in order to obtain positional information, as the angle of rotation of rotor through arctan function from the sine of solver and the merchant of cosine signal.This result can export relatively with installing current numeral then, and tracking error is provided.

In a special preferred form of the present invention, processing unit for example from solver, receives sinusoidal and cosine input signal from monitored target, determines second tracking error according to following formula:

$\sin (\mathrm{\θ}-\widehat{\mathrm{\θ}})=\sin \mathrm{\θ}\cos \widehat{\mathrm{\θ}}-\cos \mathrm{\θ}\sin \widehat{\mathrm{\θ}}---\left(1\right)$

Wherein, θ is an object's position, rotor angle for example,

Be numeral output.

Switching between two tracking errors can be carried out in any suitable manner, to improve the stability of whole converter.

In a preferred embodiment, processing unit for example when first error signal is on threshold value, switches to first error signal from second error signal based on first error signal.Threshold value for example can be 90 degree, and its purpose is to prevent that error from surpassing the maximum error value of first error signal, is pi/2 (pi/2) at the orthogonal encoder as first processing unit for example.Therefore, can stop error signal to become unstable.

Also can use other switching modes.For example, device can be with second error signal and threshold value, or and two processing units output between absolute difference compare.It can use the combination of described current numeral output and described two error signals to determine whether to switch.It can monitor error signal variations rate (rate ofchange).

Any suitable form can be adopted for providing numeral to export to the processing of first or second tracking error, and the suitable filters element can be used.Filter element can be configured to not only provide position output but also provide speed output.In a kind of preferred form, it can provide 2 class servo loops (type-2 servoloop), and can comprise two integral elements.

It can comprise integrator, is used for the error signal integration that provides produced acting on the error signal of lock-on counter so that digital output signal is increased and decreased.

Suitable transport function can be and PI (proportional integral) observer of integrator cascade that it can remove steady shape output error in response to continuous slope input.This transport function for example can be G (s)=K ₁(K ₂+ 1/s) form.Other transport functions also are possible, comprise the Kalman filter or the Luenherger wave filter of for example expansion.The form of transport function for example can be:

G(s)＝(K ₁S ²+K ₂s+K ₃)/s ²。

As previously mentioned, monitored object can be an axle, and the digital position, angle that is output as axle, and perhaps monitored object can be a slider, and digital output will provide the linear movement of this slider along scale.Speed also may be output.

Still as previously mentioned, signal generator/object monitor can be a solver, synchronizer or linear encoder, for example Inductosyn ^TMTransducer.It also may be an optical encoder.

The present invention can be used for multiple different situations.For example, it can be used for for example FEEDBACK CONTROL of motor or oil motor of motor, or is used for the detection of position, as angle or position transducer.Its purposes comprises the management and the control system of delivery vehicle, for example aviation electronics, boats and ships or automobile control, and can use at line control system for example in line control brake system, steering or the gear change system.It also can be used in Robotics or the machinery control, for example digital control to lathe.

The present invention is particularly useful under the very important situation of safety, because the present invention can conveniently stablize and the structure of the position monitor of robust.

The present invention extends to Motor Control, and it comprises the device according to above-mentioned any embodiment.

The present invention also extends to the control system of delivery vehicle, and it comprises the device according to above-mentioned any embodiment.

The present invention also extends to a kind of method, and this method will represent that the analog input of the position of monitored target converts digit position output to, and this digit position output tracking should be imported, and this method comprises:

Import to produce first tracking error between numeral output and the input in the monitoring of first resolution;

Import to produce second tracking error between numeral output and the input in second resolution monitoring that is higher than first resolution;

Determine numeral output based on first or second tracking error;

And

Between first and second tracking errors, switch the stability of following the tracks of to improve.

The present invention also extends to software, and this software is used for the control figure signal processor and will represents that the analog input of the position of monitored target converts digit position output to, this digit position output tracking input, and this software comprises:

Import to produce the assembly of first tracking error between numeral output and the input in the monitoring of first resolution;

Import to produce the assembly of second tracking error between numeral output and the input in second resolution monitoring that is higher than first resolution;

Determine that based on described first or second tracking error described numeral exports locking assembly really, described definite assembly switches between described first or second tracking error to improve tracking stability.

This software can be provided in any suitable storage medium, and the present invention extends to the storage medium that has software on it.The present invention also extends to firmware and the hardware that has embedded software code, and comprises the DSP chip that is used to carry out code of the present invention, as dsp chip.

The present invention can not use software yet and is realized electronically.For example, switch, wave filter, integrator, signal multiplier and totalizer etc. can be used realizations such as resistance, electric capacity, operational amplifier.Also can use special IC (ASIC), programmable logic device (PLD) (PLD) and programmable gate array (PGA).Final electronic equipment may be a commingled system, has not only used digital element but also used analog element.

On the other hand, the invention provides signal processing apparatus, its input signal based on the detected position of expression monitored target provides the output of digital angle, the digital output tracking input signal and the device of device comprise switching device shifter, and this switching device shifter makes the output of digital angle or based on the output of orthogonal encoder or based on the output to the sampling apparatus of input signal sampling.

From other aspect, the invention provides solver digital quantizer (resolver-to-digitalconverter), be used for exporting digital angle is provided according to the analog sine of solver, this converter comprises: orthogonal encoder, this orthogonal encoder are used for determining first jiao and provide first error signal based on the output of first jiao and converter; Observer is used for the output of solver is sampled and provided second error signal based on the solver output of sampling and the output of converter; Wave filter is used for determining converter output based on first or second error signal; And switch, when determining that converter is lost the locking that solver is exported, the wave filter input is switched to first error signal from second error signal.

On the other hand, the invention provides the digital rotor angle that the angle tracking observer is used for monitoring the output signal of solver and solver is provided, wherein this observer comprises and is used for sampling thief that the solver output signal is sampled and the orthogonal encoder that is used for monitoring the solver output signal, and wherein when dispersed with respect to the rotor angle of being represented by solver output at digital angle, this observer was determined digital angle based on the output of orthogonal encoder rather than based on the output of sampling thief.

From another aspect, the invention provides the sine input that signal processing apparatus is used to receive expression monitored target position, and the output signal of expression monitored target position is provided, this device comprises:

First error is determined assembly, and it is used for receiving sinusoidal input and determines the primary importance signal of object in first resolution, the output of receiving trap, and determine first error signal based on the output of primary importance signal and device;

Second error is determined assembly, and it is used for receiving sinusoidal input and determines the second place signal of object in second resolution that is higher than first resolution, the output of receiving trap, and determine second error signal based on the output of second place signal and device;

Assembly is determined in the position, and it provides output signal based on first or second error function; And

Changeover module determines that to the position assembly provides first or second error signal, and when output signal was tending towards dispersing, described changeover module switched to first error signal.

From other aspect, the invention provides signal processing apparatus, be used for converting the analog input of expression monitored target position to digit position output, this digit position output tracking input, this device comprises:

First processing unit, it is used for monitoring described input and being used to produce first tracking error between described numeral output and the described input in first resolution;

Second processing unit, it is used for monitoring described input and being used to produce second tracking error between described numeral output and the described input in second resolution that is higher than first resolution;

The 3rd processing unit, it determines described numeral output based on described first or second tracking error; And

Switch unit provides described first or second tracking error to described the 3rd processing unit, and described switch unit switches between described first and second tracking errors to improve tracking stability.

It should be noted that above-mentioned either side can take the circumstances into consideration to comprise any feature relevant with above-mentioned any other aspect.

Now, embodiments of the invention will be described in conjunction with the accompanying drawings, only as example.It will be appreciated that the specifics of accompanying drawing does not replace the generality of the front description of this invention, the present invention can adopt and be different from described other forms of accompanying drawing.

In the accompanying drawings:

Fig. 1 is that treating apparatus may be used on the synoptic diagram of the motor control system on it according to an embodiment of the invention.

Fig. 2 is the synoptic diagram of solver.

Fig. 3 is the schematic block diagram for the treatment of apparatus according to an embodiment of the invention.

Fig. 4 is the schematic block diagram that embodies a kind for the treatment of apparatus of Fig. 3 apparatus structure.

Fig. 5 is an a kind of synoptic diagram of method of realizing the device of Fig. 4.

Fig. 6 is the schematic block diagram that embodies the another kind for the treatment of apparatus of Fig. 3 apparatus structure.

Fig. 7 a is the simulation result curve map of first input signal " scene " to Fig. 7 d.

Fig. 8 a is the simulation result curve map of second input " scene " to Fig. 8 d.

Referring to Fig. 1, motor control system 1 comprises the motor 2 with axle 3.The control of motor 2 controlled devices 4, this controller receive command signal C and make motor 2 in the appropriate voltage energising and keep appropriate time so that the action of being ordered to be provided.

Such system uses in many application and environment.For example they can be used for providing the actuating device of delivery vehicle control system, and can be used for the delivery vehicle brake system.

Therefore, in one embodiment, motor control system can be used in the clamp brake assemblies of line control brake system, and wherein the motor 2 a pair of brake block 5 of driving (brake pads) grip brake disc 6 (brakedisc).Axle 3 can be for example by reduction gearing gear train and rotation-linear motion conversion mechanism (for example ball-screw) and brake block 5 engagements.

In this braking embodiment, controller 4 receives command signals from the electronic telecontrol unit 7 of delivery vehicle management system, and makes motor 2 in the appropriate voltage energising and keep appropriate time so that the braking maneuver of being ordered to be provided.

Electronic control unit (ECU) 7 will be according to driver's indication and riving condition issue brake command.Therefore, it is from various sensors 8 relevant with the delivery vehicle state and various sensor 9 received signals relevant with driver's wish, and corresponding various brake assemblies 1 output command signal to delivery vehicle.

Delivery vehicle sensor 8 can comprise vehicle-wheel speed sensor, accelerometer, engine sensor, driftage (head shakes, yaws, yawing) sensor, Abgassensor etc., and driver's indicator/require sensor (man-machine interaction sensor (HMI)) can comprise braking or accelerator pedal sensor and steering wheel sensor.For example, brake pedal sensor can provide and the proportional signal of driver's brake request, as being determined to the strength that pedal applies by the amount of movement of pedal or driver's pin.

ECU7 can control the braking of delivery vehicle according to many different modes of braking.It can only follow driver's indication, perhaps can provide some interventions, as ABS (Anti-lock Braking System) (ABS), traction control, delivery vehicle stability or brake hard control are provided.

Electronic control unit 7 can be communicated by letter by any suitable mode with brake caliper assembly 1, can link together separately as them, and/or connect by one or more communication buss.

Accurately operated in order to ensure motor 2, controller 4 is with feedback system control motor 2, and motor 2 comprises that on its axle 3 solver 11 is with position, the angle θ that expression motor reel 3 is provided and the feedback signal of angular velocity omega.Controller 4 can change the energising of motor 2 then and guarantee to finish rightly the action of being ordered, for example braking maneuver.For example the converter in controller 4 13 converts the simulation output of solver 11 to be used for controller 4 numeral input.

Solver 11 is as shown in Fig. 2 is concise and to the point.It comprises rotor 20 and a pair of orthogonal stator coil 22 and 23 that wherein have coil 21, and this is to coil and rotor winding 21 couplings.Use AC signal V _RefTo producing the identical signal of frequency in energising each in stator coil 22 and 23 of rotor winding 21, but the intensity of coupling changes with sinusoidal manner when rotor 20 rotations, make the output signal that comes from each stator coil 22,23 be carried out amplitude modulation(PAM) by the sinusoidal envelope line.Because stator coil is vertical mutually, the envelope of two stator coils differs 90 degree mutually, so stator coil 22 produces the sinusoidal signal envelope of relative rotor-position, stator coil 23 produces the cosine signal envelope.

Correspondingly, solver 11 provides sin (θ) signal V _SinAnd cos (θ) signal V _Cos, and pass through described two signals of point measurement at any time, can obtain the absolute angular position θ of rotor.Also can determine the speed that rotor angle θ changes from described two signals, so that rotor velocity ω to be provided.

The present invention relates to the processing of position signalling, for example the Signal Processing that provides of solver 11 and analog position signal are to the conversion of digital signal.Therefore its converter 13 that can be applied to motor control system is to provide digital rotation angle according to analog input 12 With digital angular velocity

Although the present invention also has the application widely at any processing from analog to digital of position signalling, for example generally speaking in the field of position transducer and actuating device.

The general structure of one embodiment of the present of invention as shown in Figure 3, its form is a solver digital quantizer 30, this converter is by making digital output tracking analog input, determines digital angular position according to the analog sine input Vsin and the Vcos of solver With digital angular velocity

Therefore it can be called as the angle tracking observer.

Converter 30 comprises first processing unit 31, and it is with first (low) resolution monitoring solver output and produce actual rotor angle θ and the digital angle of output

Between the first tracking error e ₁It also comprises second processing unit 32, and it is with second (higher) resolution monitoring solver output and produce actual rotor angle θ and the digital angle of output

Between the second tracking error e ₂

Wave filter 33 receives first or second error signal e ₁Or e ₂, and be configured to the transport function that provides suitable, so that can obtain digital rotor angle from error signal

And/or digital rotor velocity These digital signals can be used in the FEEDBACK CONTROL to motor 2 that is provided by controller 4 then.

Switch 34 is with first or second error signal e ₁Or e ₂Be connected with wave filter 33, and this switch is by two error signal e ₁And e ₂Between 35 excitations of the switching controls switched, keep stable with the output of guaranteeing converter.Whether therefore, switching controls 35 can receive wherein any or two numeral output and wherein any or two tracking errors, and determine according to these whether numeral output is lost its locking and exported and tend to respect to input drift or disperse.

General, switching controls 35 provides the second tracking error e to wave filter 33 ₂Determine rotor angle and speed with high resolving power ground.Yet when determining numeral output losing lock, switching controls 35 provides low resolution tracking error e to wave filter 33 ₁This makes the output of converter keep stable, because the low resolution processing unit is subjected to the influence of noise, sensor drift etc. less, therefore can provide than the more output of robust of the second high-resolution processing unit.

First processing unit for example can pass through the discrete event of the version that passes through processing or shaping of monitoring input signal or input signal, for example zero crossing or edge incident, rising edge or negative edge such as waveform, determine the position, and second processing unit can pass through the many points of input signal in its cycle, for example, be included in the many points between the discrete event, sample and monitor input signal.

The example more specifically of device shown in Figure 3 is illustrated in the converter 40 of Fig. 4.In this case, first processing unit comprises orthogonal encoder 41a.It is right that this scrambler receives described solver output, and they are adjusted to the square wave of a pair of phase phasic difference 90 degree.Scrambler 41a is rising and/or the negative edge by the monitoring square-wave pulse for example then, axle 3 the position of motor is defined as being arranged in complete swing circle four quadrants depend on the some of amplitude on each input signal channel.

Therefore, this to the amplitude of square wave to can be " 1,1 ", " 1,0 " " 0,1 " or " 0,0 ", this depends on which quadrant rotor angle is positioned at.Scrambler 41a determine then amplitude to and can determine rotor angle (and obtain the direction of rotor motion by the order that it is right that amplitude is received in monitoring) in the pi/2 (pi/2) thus.Scrambler 41a exports detected rotor angle quadrant, and comparer 41b is from wherein deducting current digital output angle

So that the first tracking error signal e to be provided ₁

Therefore, first tracking error is based on:

${\mathrm{\θ}}_{\mathrm{qund}}-\widehat{\mathrm{\θ}}=\frac{\mathrm{\π}}{2}{N}_{\mathrm{qund}}-\widehat{\mathrm{\θ}}=\frac{\mathrm{\π}}{2}\[\frac{(\mathrm{\θ}+\frac{\mathrm{\π}}{2})}{\frac{\mathrm{\π}}{2}}\]-\widehat{\mathrm{\θ}}---\left(2\right)$

Wherein, N _QuadBe quadrant number, [] expression is rounded to immediate integer downwards.

Second processing unit comprises a pair of multiplier 42a and 42b, and they are with described two solver input signal V _SinAnd V _CosRespectively with the digital output angle of determining by cosine and forcing function generator 42c and 42d

Cosine and sine value multiply each other.The result of two multipliers is sent to comparer 42e then so that the second tracking error e to be provided ₂

Therefore, the second tracking error e ₂Obtain by following trigonometric identity:

$\sin \left(\mathrm{\θ}-\widehat{\mathrm{\θ}}\right)=\sin \mathrm{\θ}\cos \widehat{\mathrm{\θ}}-\cos \mathrm{\θ}\sin \widehat{\mathrm{\θ}}---\left(3\right)$

It should be noted that, work as sin

Hour,

Therefore, when The time, then also have

In addition, to little error, closed-loop system is almost linearity.

Converter 40 also comprises filter cell 43a and 43b, and it adopts error signal e ₁Or e ₂In one or another and the digital angular position of rotor is provided With digital angular velocity Filter element comprises the PI observer 43a with integrator 43b cascade, and it can eliminate steady shape output error in response to continuous slope input.Transport function G (s) for example can for:

G(s)＝K ₁(K ₂+1/s) (4)

Yet also can be other transport functions, for example Kuo Zhan Kalman filter or Luenberger observer.It for example can be

G(s)＝(K ₁s ²+K ₂s+K ₃)/s ² (5)

In this example two error signal e ₁And e ₂Between switching be by from quadrant processing unit 41a, the error signal e of 41b ₁Absolute value determine.Therefore piece 45a takes error signal e away ₁Absolute value and this value in comparer 45b, compare with threshold value.The result passes to piece 45c then, the symbol of its determination result, and export " 0 " less than 0 the time when comparer output, otherwise be output as " 1 ".If switch 44 is received control signal " 1 ", then transmission error signal e ₁If receive control signal " 0 ", then transmission error signal e ₂

Therefore, follow the tracks of the general high resolution system that forms by second processing unit and wave filter that uses and carry out, so that the precise monitoring to solver rotor 20 (thereby motor reel 2) to be provided.Yet,,,, use orthogonal encoder to continue tracking for tackling this situation just determine the output losing lock when the error signal between analog input and the numeral output (as by the orthogonal encoder decision) during greater than the value of setting M (as 90 degree).In case locking recovers, converter recovers the tracking based on the High-resolution Processing unit.Therefore, the output of converter is the mixed of orthogonal system and sampling system.

Second processing unit is provided with first processing unit by the tracking that provides the high-resolution of motor shaft angle θ.Yet first processing unit is compared more robust and stable of second processing unit, like this, by with both combinations, present embodiment can make converter in tracking generally not only accurately but also stable, therefore can realize the good control of 6 pairs of motor 2 of controller.

Switch unit 44 does not need only based on the first tracking error e ₁With threshold value relatively come work, can carry out other any suitable monitorings, with the stability of determining output with disperse to output signal.For example, the absolute difference between second tracking error or two errors can with threshold ratio.

Fig. 5 illustrates the converter similar to Fig. 4 50, but shows various nextport hardware component NextPorts.In this embodiment, a pair of multiplication DAC52a and 52b are respectively with analog input V _SinAnd V _CosWith digitally produced

With

Function multiplies each other and their output is offered summing amplifier 52c, the output of amplifier 52c by detuner 52d so that error signal e to be provided ₂

Error signal e ₂To the digital filter 53a that transport function (such as in above-mentioned (4) or (5)) is provided, and integrator 53b (it removes the hysteresis error relevant with the motor reel that rotates with fixed angles speed 3) is passed in the output of this wave filter by switch 54.The output of integrator 53b is passed to voltage-controlled oscillator 53c and is followed the tracks of input to produce fixed frequency.This control bi-directional counter 53d goes to calculate polarity, and rotation is upwards counted to forward, and (thereby the second integral device is provided) counted in reverse rotation downwards.

Orthogonal encoder 51a comprises a pair of Schmidt trigger 51b that is used to provide a pair of square wave, and counter 51c, this counter 51c determines rotor angles with the precision of pi/2 (pi/2) from two square wave input channels, and summing amplifier 51d is passed in its output, by deducting digital error signal

Error signal e is provided ₁Error signal e ₁Also be used for controlling switch 54, make and work as error signal e ₁When surpassing certain threshold level, switch 54 transmission error signal e ₁And transmission error signal e not ₂

As can be seen, the operation class of converter 50 is like phaselocked loop, and it produces local frequency and adjusts it to follow the tracks of frequency input signal.

Fig. 6 illustrates an alternative embodiment of the invention, wherein converter 60 comprises quadrature converter 61a and comparer 61b in the mode identical with Fig. 4, but wherein High-resolution Processing is carried out by piece 62a, and piece 62a is applied to arctan function the merchant of sinusoidal and cosine input signal.Therefore, piece 62a is according to following formula output rotor angle θ:

$\mathrm{\θ}\≡\arctan 2\left(\frac{V_{\sin }}{V_{\cos }}\right)---\left(6\right)$

Wherein, arctan2 is the four-quadrant arctan function.

This signal outputs to comparer 62b, so that switch will be from the error signal e of orthogonal encoder ₁Or from the error signal e of arc tangent scrambler ₂Pass to filter element 63a and 63b, thereby determine the digital angular position and the angular velocity of motor reel 3.

In above all situations, converter provides stable and exact figure output, and this numeral is exported accurately tracking signal input, thereby guarantees accurate FEEDBACK CONTROL.

With reference now to Fig. 7 a-7d and Fig. 8 a-8d, two emulation are described.

Under first kind of situation of Fig. 7 a-7d, actual position, angle is with higher fixedly acceleration alpha=500 radian per seconds ²Change, and under second kind of situation of Fig. 8 a-8d, actual angle change in location pattern is the sinusoidal curve that is given by θ (t)=200 π sin (0.4 π t), also has to be 500 radian per seconds to the maximum ²Angular acceleration.Emulation has all been carried out 80 seconds in both cases, and because noise effect, is positioned on the pure sinusoid and cosine signal that solver that white noise [0.1,0.1] border in is added to emulation exports.

Fig. 7 a, 7b and 8a, 8b illustrate the output of known observer, and Fig. 7 c, the output of the observer when 7d and 8c, 8d illustrate transport function below using of embodiment according to Fig. 4:

$G\left(s\right)=\frac{{25\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20068000669900201.png,A20068000669900221.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+211s+915}{s^2}---\left(7\right)$

The observer of described two kinds of known types is: (i) the basic solver converter of Fig. 4 form and use transport function (7), but do not have orthogonal encoder or switch unit and (ii) Kalman filtering observer.

Under first situation, referring to Fig. 7 a and 7b as can be known, basic solver converter and Kalman filtering are neither stable, yet, referring to Fig. 7 c, according to the estimator of Fig. 4 form is stable and its evaluated error converges to zero (for simplicity's sake, Fig. 7 has only drawn the curve on [0,5] second interval) after indicial response.

Fig. 7 d illustrates switch mode, and wherein when using the high resolving power sampling thief, binary zero is used to adjust output, and when using the orthogonal encoder counting, binary one is used to adjust output.

Equally, referring to Fig. 8 a and 8b, heavy second kind of situation as can be seen, basic solver converter and Kalman filter are all unstable, yet (have only drawn for simplicity's sake, [0 shown in Fig. 8 c, 10] curve on second interval), the position estimation error of the embodiment of Fig. 4 is stable equally.In this case, although evaluated error is not asymptotic going to zero, it is limited at ± 2 degree in.

Switch mode is illustrated among Fig. 8 d, and mode is similar to Fig. 7 d, but for brevity, has only drawn the curve map on [9.4,9.5] second interval.

Although above-mentioned discussion concentrates on the motor control of clamp detent, be appreciated that the present invention may be used on many other systems, for example comprise other delivery vehicle control system, for example wire-controlled steering system and shift-by-wire control system.

Be appreciated that the present invention's also being widely used outside delivery vehicle control and motor control, can relate to the system that analog position information accurately need be converted to numerical information usually.The present invention is particularly useful under the very important situation of safety, because converter according to the present invention has promoted accurate and stable numeral output.

The present invention can use with actuating device, and for example motor or oil motor are to provide FEEDBACK CONTROL.The present invention also can use with sensor, and angle transducer for example is to provide the positional information about monitored target.

The present invention for example can be used in the delivery vehicle control system, for example Aerospace Control system or automotive control system.The present invention for example also can be used for Robotics, military systems and the control of machinery generally speaking, for example to the control of numerically-controlled machine.

Solver output is the same with being applied to, and the present invention also may be used on the output of other sensors, for example comprises synchrodyne.Synchrodyne is similar to solver, but 3 coils are arranged.Solver and synchrodyne both provide the information of rotation, but the information of linear movement also may be provided, for example the use that connects by ball-screw.In addition, the present invention can be used for direct linear-movement pickup, for example inductosyn ^TMEquipment, it comprises the scale that made by printed circuit traces (this scale uses reference voltage energising) and the slider that moves along scale and have the pair of traces of same pitch with scale, but wherein a trace separates with another trace with the skews of 90 degree.Like this, the output class of two sliders is similar to the output of solver.

The present invention also can with scrambler for example light positive string scrambler use, light positive string scrambler shines light on the disk by grating.

Although described embodiment has illustrated error signal is switched to the 3rd processing unit from first pair of processing unit, can there be other equivalent configurations in system, and for example, in equivalent structure, the switching position signal is also determined error based on the position signalling that switches.

The present invention can be used for the analog input of many types, and for example, although be preferred, signal needs not be sinusoidal signal, and can be the proper signal that any permission positional information is resolved.Input signal also needs not be 90 degree out-phase, also can use other phase relations.

The present invention can realize in any suitable manner, for example is embodied as hardware element, coding in digital signal processor (DSP) chip, and/or in software, provide.

It will be appreciated that, without departing from the scope of the invention, can carry out various replacements to part in preceding description, increase and/or modification, and, as those skilled in the art are accessible, according to above-mentioned instruction, the present invention can be in software, firmware and/or hardware accomplished in various ways.

Claims (31)

1. signal processing apparatus, the analog input that is used for expression is monitored object's position converts digit position output to, the described sinusoidal input of described digital output tracking, described device comprises processing unit, this processing unit is used for:

Monitor described input by first resolution, to produce first tracking error between described numeral output and the described input;

Monitor described input by second resolution that is higher than described first resolution, to produce second tracking error between described numeral output and the described input; And

Determine described numeral output based on described first or second tracking error, described processing unit provides between the described numeral output in described first and second tracking errors of use and switches, to improve tracking stability.

2. device as claimed in claim 1, wherein said input are sinusoidal inputs.

3. device as claimed in claim 1 or 2, wherein said input comprises sinusoidal signal and cosine signal.

4. as the described device of claim 1,2 or 3, wherein said processing unit comes to monitor by described first resolution by the discrete event that monitors described input, and monitors by described second resolution by described input sample is come.

5. as at the described device of preceding any claim, wherein said processing unit comprises regulon, and it is used for regulating the square wave input of described input to be provided for monitoring by described first resolution.

6. device as claimed in claim 5, wherein said processing unit monitor that the rising of described square wave input and/or negative edge are to monitor the position of described object.

7. as at the described device of preceding any claim, wherein said processing unit comprises the orthogonal encoder that is used for determining based on the input signal of a pair of phase splitting described primary importance signal.

8. as at the described device of preceding any claim, wherein said processing unit comes to monitor by described second resolution based on the arctan function from the sinusoidal input signal of the described a pair of phase splitting that is monitored object.

9. as the described device of arbitrary claim in the claim 1 to 7, wherein said processing unit receives sinusoidal and cosine input signal from the described object that is monitored, and determines described second tracking error according to following formula:

$\sin (\mathrm{\&theta;}-\widehat{\mathrm{\&theta;}})=\sin \mathrm{\&theta;}\cos \widehat{\mathrm{\&theta;}}-\cos \mathrm{\&theta;}\sin \widehat{\mathrm{\&theta;}}$

Wherein, θ is an object's position,

Be numeral output.

10. as at the described device of preceding any claim, wherein said processing unit comprises first processing unit that is used for exporting described first error signal, be used for exporting second processing unit of described second error signal, determine the 3rd processing signals that described numeral is exported and the switch unit that described first or second tracking error is switched to described the 3rd processing unit based on described first or second error signal.

11. as at the described device of preceding any claim, wherein when described first error signal was higher than threshold value, described processing unit used described first error signal so that described numeral output to be provided.

12. as at the described device of preceding any claim, wherein said processing unit comprises described first or second error signal is carried out integration to produce the integrator of described digital output signal.

13. as at the described device of preceding any claim, wherein said processing unit provides 2 class servo loops.

14. as at the described device of preceding any claim, wherein said processing unit is determined the described speed that is monitored object from described first or second error signal.

15. as at the described device of preceding any claim, wherein said be monitored to as if axle, and wherein said numeral output is the position, angle of described axle.

16. as at the described device of preceding any claim, wherein said be monitored to as if slider on scale.

17. as at the described device of preceding any claim, wherein said input is from solver.

18. as the described device of arbitrary claim in the claim 1 to 16, wherein said input is from scrambler.

19. as the described device of arbitrary claim in the claim 1 to 16, wherein said input comes Autosyn.

20. as the described device of arbitrary claim in the claim 1 to 16, wherein said input is from linear position sensor, described linear position sensor comprises the reference scale of the patterned circuit of using the reference voltage energising, with the slider that moves along described scale, described slider have a pair of pitch with reference to the identical patterned circuit of scale pattern, but one of them patterned circuit is with respect to another patterned circuit with the skews of 90 degree separately.

21. a motor controller comprises according to any at the described device of preceding claim.

22. a position transducer comprises according to any one described device in the claim 1 to 20.

23. a delivery vehicle control system comprises according to any at the described device of preceding claim.

24. the analog input that expression is monitored the position of object converts the method for digit position output to, the described input of described digit position output tracking, and described method comprises:

Monitor that by first resolution described input is to produce first tracking error between described numeral output and the described input;

Monitor that by second resolution that is higher than described first resolution described input is to produce second tracking error between described numeral output and the described input;

Determine described numeral output based on described first or second tracking error; And

Between described first and second tracking errors, switch the stability of following the tracks of to improve.

25. one kind is used for analog input that the control figure signal processor is monitored the position of object with expression and converts the software of digit position output to, the described input of described digit position output tracking, and described software comprises:

Monitor that by first resolution described input is to produce the assembly of first tracking error between described numeral output and the described input;

Monitor that by second resolution that is higher than described first resolution described input is to produce the assembly of second tracking error between described numeral output and the described input; And

Determine that based on described first or second tracking error described numeral exports locking assembly really, described definite assembly switches between described first and second tracking errors to improve tracking stability.

26. a storage medium is comprising the described software of claim 25.

27. one kind is monitored the input signal of the position that object is detected based on expression and the signal processing apparatus of digital angle output is provided, the described input signal of described digital output tracking of described device, described device comprise makes the output of described digital angle or based on the output of orthogonal encoder or based on the switch of the output of the sampling apparatus of the described input signal of sampling.

28. a solver digital quantizer that is used for providing from the output of the analog sine of solver digital angle, described converter comprises: be used for determining first jiao and the orthogonal encoder of first error signal is provided based on described first jiao and the output of described converter; Be used for described solver is exported the observer of sampling and second error signal being provided based on the output of solver output of sampling and described converter; Determine the wave filter of described converter output based on described first or second error signal; And when judging that described converter is lost the locking that described solver is exported, described wave filter input is switched to the switch of described first error signal from described second error signal.

29. angle tracking observer that is used to monitor the solver output signal and the digital rotor angle of described solver is provided, wherein said observer comprises the sampling thief and the orthogonal encoder that monitors described solver output signal that is used for to described solver output signal sampling, and wherein when disperse with respect to the indicated described rotor angle of described solver output at described digital angle, described observer is based on the output of described orthogonal encoder rather than determine the digital angle of rotor based on the output of described sampling thief.

30. one kind is used for receiving expression and is monitored the sine input of object's position and provides expression to be monitored the signal processing apparatus of the output signal of object's position, this device comprises:

First error is determined assembly, and it is used for receiving described sinusoidal input and determines to receive the primary importance signal of object the output of described device, and determine first error signal based on the output of described primary importance signal and described device by first resolution;

Second error is determined assembly, it is used for receiving the described sinusoidal second place signal of importing and determining object by second resolution that is higher than described first resolution, receive the output of described device, and determine second error signal based on the output of described second place signal and described device;

Assembly is determined in the position, and it provides described output signal based on described first or second error function; And

Changeover module is used for determining that to described position assembly provides described first or second error signal that when described output signal was tending towards dispersing, described changeover module switched to described first error signal.

31. a signal processing apparatus that is used for the analog input that expression is monitored object's position is converted to digit position output, the described input of described digital output tracking, described device comprises:

First processing unit, it is used for monitoring described input and being used to be created in first tracking error between described numeral output and the described input by first resolution;

Second processing unit, it is used for monitoring described input and being used to be created in second tracking error between described numeral output and the described input by second resolution that is higher than first resolution;

The 3rd processing unit, it determines described numeral output based on described first or second tracking error; And

Switch unit is used for providing described first or second tracking error to described the 3rd processing unit, and described switch unit switches between described first and second tracking errors to improve tracking stability.

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