CN115388834A - Loosening gap detection and early warning method for intermediate shaft of electric power steering system - Google Patents
Loosening gap detection and early warning method for intermediate shaft of electric power steering system Download PDFInfo
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- CN115388834A CN115388834A CN202211031675.3A CN202211031675A CN115388834A CN 115388834 A CN115388834 A CN 115388834A CN 202211031675 A CN202211031675 A CN 202211031675A CN 115388834 A CN115388834 A CN 115388834A
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- 238000001514 detection method Methods 0.000 title claims abstract description 159
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- 238000002347 injection Methods 0.000 claims description 12
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/16—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring distance of clearance between spaced objects
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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
- B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
- B62D5/0481—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures
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Abstract
The invention relates to the technical field of electric power steering systems, in particular to a method for detecting and early warning looseness clearance of an intermediate shaft of an electric power steering system, which can implement active detection compared with the prior art, and can timely early warn a driver of light explosion and reduce power assistance when the intermediate shaft of a pipe column type electric power steering system has an abnormal condition of overlarge looseness clearance; the abnormal condition that the intermediate shaft is loose and has overlarge clearance can be accurately and effectively detected and warned on the normal road surface and the low-attachment road surface, so that the potential safety hazards such as cross shaft disengagement and the like possibly caused by overlarge clearance of the cross shaft of the intermediate shaft under the extreme working condition are reduced, the safe driving of the vehicle is ensured, the safety performance of the whole vehicle is improved, and the unnecessary loss of a whole vehicle factory and a client is effectively reduced; when the abnormal condition that the intermediate shaft is loose and has overlarge clearance does not exist, the subjective feeling of a terminal driver is not influenced by active detection, and the safety of vehicle running is controllable after the active detection is activated.
Description
Technical Field
The invention relates to the technical field of electric power steering systems, in particular to a loose clearance detection and early warning method for an intermediate shaft of an electric power steering system.
Background
In some vehicles, due to the fact that gaps on one side or two sides of a cross shaft bearing are too large under extreme use working conditions of over fatigue, friction, impact and the like, the cross shaft can be separated seriously and even caused, potential safety hazards of vehicle running are increased, and the safety performance of the whole vehicle is influenced.
The gap detection device for the intermediate shaft of the automobile steering system is researched to a certain extent: utility model patent application No. 202122643229.5 discloses a car turns to jackshaft clearance measuring device, has realized high-efficient and accurate measurement car turns to jackshaft clearance. Utility model patent application No. 201821781512.6 discloses another jackshaft clearance detection device, and the device is used for the circumferential clearance between each moving part of accurate measurement jackshaft. However, no special software technology is available at present, and detection and early warning are realized for the abnormal condition that the intermediate shaft is loose and has overlarge clearance.
Therefore, an early warning method for detecting loose clearances of intermediate shafts of an electric power steering system needs to be designed, active detection can be implemented, early warning is timely performed on a driver, and power assisting is reduced, so that potential safety hazards such as cross shaft disengagement possibly caused by overlarge clearances of the cross shafts of the intermediate shafts under extreme working conditions are reduced, safe driving of vehicles is ensured, the safety performance of the whole vehicle is improved, and unnecessary losses of a whole vehicle factory and customers are effectively reduced.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a method for detecting and early warning the loose clearance of an intermediate shaft of an electric power steering system, which can carry out active detection, early warn a driver in time and reduce power assistance, thereby reducing potential safety hazards such as cross shaft disengagement and the like possibly caused by overlarge clearance of the cross shaft of the intermediate shaft under extreme working conditions, ensuring the safe driving of a vehicle, improving the safety performance of the whole vehicle and effectively reducing unnecessary losses of a whole vehicle factory and a client.
In order to achieve the purpose, the invention provides a method for detecting and warning looseness gap of an intermediate shaft of an electric power steering system, which comprises the following steps of:
and step 1, the steering controller acquires the vehicle driving mileage and judges whether the vehicle driving mileage exceeds the minimum detection mileage limit value allowed to be activated, if so, the step 2 is continued, and if not, the detection is finished.
And 2, the steering controller acquires the system state of the current electric power steering system, the vehicle ignition state, the vehicle speed, the hand torque of the steering wheel, the state of a steering angle sensor, the current steering wheel angle and a signal value stored in a nonvolatile storage module in a power-off mode.
And 3, when the system state of the electric power steering system is normal and simultaneously meets the conditions that the vehicle speed is less than the maximum vehicle speed set value, the hand torque of the steering wheel is less than or equal to the maximum hand torque set value, the state of the corner sensor is normal, the current steering wheel corner is less than or equal to the maximum corner set value, and the accumulated recorded fault times are less than the minimum alarm times, continuing to perform the step 3 to start detection, wherein the detection time does not exceed the maximum set detection time value, and otherwise, finishing the detection.
And 5, if the change of the actual turning angle of the steering wheel exceeds the maximum set value, the loose clearance of the current intermediate shaft is too large, the accumulated failure times are increased once, and if the change of the actual turning angle of the steering wheel does not exceed the maximum set value, the loose clearance of the current intermediate shaft is normal, and the detection is finished.
In the step 1, the minimum detection mileage limit value is smaller than the average mileage when loose intermediate shafts are detected to be too large in the bench durability test, and the minimum detection mileage limit value can be calibrated.
In the step 4, the mechanical static friction moment of the pipe column is calibrated by a real vehicle, and the calibrating steps are as follows: step 1a, a fault part with a loose middle shaft and an overlarge gap is arranged on a vehicle, the vehicle is statically placed on a flat road surface with a low adhesion coefficient, a steering wheel is placed in a middle position, and the steering wheel is in a free state without a connecting pipe; step 2a, setting the compensation torque as 0, and setting the smoothness factor of the detection torque along with the change of the steering wheel angle as 1; step 3a, injecting the initial fixed motor torque as injection torque into a steering wheel, observing whether the angle of the steering wheel changes, and if the steering wheel rotates, gradually reducing the injection torque according to a set torque gradient; if the steering wheel does not rotate, gradually increasing the injection torque according to a set torque gradient; and 4a, repeating the step 3a until the injection torque critical value which enables the steering wheel to be basically kept still and enables the observation corner signal to be smaller than the set angle is obtained, namely the mechanical static friction torque of the pipe column.
In the step 4, the compensation torque is calibrated by using a real vehicle, and the calibration steps are as follows: step 1b, setting the mechanical static friction moment of the pipe column as a calibrated moment value; step 2b, setting the initial value of the compensation torque as 0Nm, and setting the smoothness factor of the detection torque along with the change of the steering wheel angle as 1; step 3b, a fault part with loose middle shaft and overlarge gap is installed on the vehicle, the vehicle is statically placed on a flat road surface, the steering wheel is placed in the middle position, and the steering wheel is in a free state without connecting pipes; step 4b, injecting detection motor torque to the left and the right respectively, simultaneously gradually increasing a compensation torque value on the basis of an initial value of the compensation torque according to a set torque gradient, observing whether the steering wheel rotates, and recording the angle difference of the steering wheel towards the left and the right; step 5b, repeating the step 4b, and taking a critical value when the angle difference of the steering wheel is larger than the set angle as a compensation moment intermediate value; step 6b, installing a non-failure part of the intermediate shaft, which is not loosened, on the vehicle, placing the vehicle on a flat road surface in a static manner, placing the steering wheel in a middle position, and enabling the steering wheel corner to be within a function activation range; step 7b, injecting the torque of the detection motor to the left and the right respectively, observing the change of the angle of the steering wheel, and simultaneously gradually reducing the compensation torque value on the basis of the intermediate value of the compensation torque according to the set torque gradient; and 8b, repeating the step 7b, and taking the critical value when the difference value of the angle signals of the steering wheel is smaller than the set angle, namely the compensation moment.
In step 4, the ride comfort factor curve of the detection torque changing along with the steering wheel angle is calibrated by a real vehicle, and the calibration steps are as follows: step 1c, setting the mechanical static friction torque of the pipe column as a calibrated torque value, setting the compensation torque as a calibrated torque value, and setting the initial values of the smoothness factor curves of the detection torque along with the change of the steering angle of the steering wheel as 1; step 2c, a fault part with loose middle shaft and overlarge gap is installed on the vehicle, the vehicle is statically placed on a flat road surface, the steering wheel is placed in the middle position, and the steering wheel is in a pipe connection state when being held by both hands; step 3c, injecting motor torque, and observing the gradient of hand torque of the steering wheel in the process that the rotation angle of the steering wheel is increased from 0 degree to a set angle; step 4c, gradually reducing the smoothness factor of the detection torque along with the change of the steering wheel angle according to the set gradient until the gradient of the hand torque of the steering wheel is smaller than the set critical value and the gradient is used as the value of the smoothness factor under the corresponding set angle; and 5c, repeating the step 3c and the step 4c, obtaining the value of the smoothness factor under the corresponding corner in the process that the steering wheel corner is gradually increased to the maximum corner, and forming a smoothness factor curve of the detection torque changing along with the steering wheel corner according to the values of the smoothness factors under all corners.
And 4, performing boundary limit protection on the output detection torque and monitoring the vehicle speed, when the vehicle speed is greater than a maximum set value, reducing the output detection torque to 0, and when the vehicle speed is in a set range, limiting the slope of the output detection torque according to a curve of the slope limit of the output detection torque along with the vehicle speed, so as to ensure the safety and controllability of the vehicle in the driving process.
The curve of the output detection torque slope limit value along with the vehicle speed needs real vehicle calibration, and the calibration steps are as follows: step 1d, setting the mechanical static friction torque of the pipe column as a calibrated torque value, setting the compensation torque as a calibrated torque value, setting a smoothness factor curve of the detection torque changing along with the steering wheel angle as a calibrated value, and setting an initial value of a curve of the output detection torque slope limit along with the vehicle speed; step 2d, accelerating the vehicle, keeping the vehicle speed at a fixed speed, injecting and outputting a detection torque, and observing the vehicle offset; step 3d, if the vehicle offset exceeds the maximum set value, reducing the output detection torque slope value according to the set gradient, if the vehicle offset does not exceed the maximum set value, increasing the output detection torque slope value according to the set gradient until a critical value that the vehicle offset does not exceed the maximum set value is obtained and used as the output detection torque slope limit value under the corresponding vehicle speed; and 4d, repeating the step 2d and the step 3d, obtaining the slope limit value of the output detection torque under the corresponding vehicle speed in the process that the vehicle accelerates to the maximum working set value, and forming a curve of the slope limit value of the output detection torque along with the vehicle speed according to the slope limit values of the output detection torque under all the vehicle speeds.
In the step 4, the detection torques are respectively output to the left and the right, and the step of detecting the change of the actual rotation angle of the current steering wheel is as follows: step 1f, continuously outputting the detection torque to the left until a detection time set value is reached, and recording a first steering wheel angle at the moment; step 2f, continuously outputting the detection torque to the right until a detection time set value is reached, and recording a second steering wheel angle at the moment; and 3f, calculating the difference value of the first steering wheel angle and the second steering wheel angle.
and 7, if the steering system detects that the intermediate shaft is loose and has overlarge clearance and explodes a red light, the steering system reduces the power assistance and maintains the red light state until a diagnosis service fault clearing signal is received, and all faults and fault times are cleared.
Compared with the prior art, the invention can implement active detection, and can early warn a driver to burst light and reduce the power when the intermediate shaft of the tubular column type electric power steering system has an abnormal condition of overlarge clearance; the abnormal condition that the intermediate shaft is loose and has overlarge clearance can be accurately and effectively detected and warned on the normal road surface and the low-attachment road surface, so that the potential safety hazards such as cross shaft disengagement and the like possibly caused by overlarge clearance of the cross shaft of the intermediate shaft under the extreme working condition are reduced, the safe driving of the vehicle is ensured, the safety performance of the whole vehicle is improved, and the unnecessary loss of a whole vehicle factory and a client is effectively reduced; when the abnormal condition that the intermediate shaft is loose and has overlarge clearance does not exist, the subjective feeling of a terminal driver is not influenced by active detection, and the safety of vehicle running is controllable after the active detection is activated.
Drawings
FIG. 1 is a software system architecture diagram of the present invention.
FIG. 2 is a flow chart of the detecting method for loose spacing of the intermediate shaft according to the present invention.
FIG. 3 is a graph of the ride comfort factor of the present invention sensed torque as a function of steering wheel angle.
FIG. 4 is a graph of output sensed torque slope limit of the present invention versus vehicle speed.
FIG. 5 is a sensed torque output algorithm diagram of the present invention.
FIG. 6 is a flow chart of the method for warning of loose spacing between shafts in the present invention.
Detailed Description
The invention will now be further described with reference to the accompanying drawings.
In this embodiment, the software architecture is as shown in fig. 1, and includes a communication input module 1, a steering wheel torque angle module 2, a nonvolatile storage module 3, an open gap detection state machine module 4, a detection torque calculation module 5, an early warning state calculation module 6, a safety check module 8, a diagnosis module 7, a communication output module 9, and a motor control module 19. The communication input module 1 receives a vehicle speed signal, a steering wheel corner signal, a vehicle traveling mileage signal and an ignition state signal from a whole vehicle communication node, and is connected with the input end I of the loose clearance detection state machine module 4. The steering wheel torque angle module 2 outputs a steering wheel torque and angle signal, and is connected with the second input end of the loose gap detection state machine module 4. The nonvolatile storage module 3 outputs a power-off storage signal and is connected with the third input end of the loose gap detection state machine module 4 and the first input end of the early warning state calculation module 6. The loose clearance detection state machine module 4 calculates the current loose clearance detection control state in real time according to the input signal, and is connected with the input end I of the detection torque calculation module 6. The detection torque calculation module 5 calculates a difference value between a motor torque required by detection and an actual steering angle of the steering wheel, performs gradient and boundary limit values on the output motor detection torque, and is connected with the second input end of the early warning state calculation module 6 and the first input end of the safety check module 8. The early warning state calculation module 6 calculates the failure times and the early warning lamp yellow lamp red lamp state, and is connected with the first input end of the nonvolatile storage module 3 and the first input end of the diagnosis module 7. The diagnosis module 7 detects diagnosis service and is connected with the second input end of the early warning state calculation module 6. The safety checking module 8 monitors the vehicle speed, when the vehicle speed is greater than the minimum safe vehicle speed, the output torque is directly reduced to 0, the safety and controllability of the output torque are guaranteed, otherwise, the detection torque is output, and the motor control module 10 is connected with the input end of the motor control module to control the motor.
The method for detecting the loose clearance of the intermediate shaft does not need to install an additional sensor, only needs to obtain necessary input signals from an electric power steering system and a CAN communication node of the whole vehicle, and saves cost.
The method for detecting the loose clearance of the intermediate shaft comprises the following steps, which are further explained by combining the flow chart of the method for detecting the loose clearance of the intermediate shaft in the embodiment of fig. 2:
and step 1, the steering controller acquires the vehicle driving mileage and judges whether the vehicle driving mileage exceeds the minimum detection mileage limit value allowed to be activated, if so, the step 2 is continued, and if not, the detection is finished.
The minimum detection mileage limit value is smaller than the average mileage when the loose gap of the intermediate shaft is too large in the bench durability test, and the minimum detection mileage limit value can be calibrated.
In this embodiment, a vehicle mileage signal is first obtained, and if the vehicle mileage signal does not exceed the minimum detection mileage limit value that allows activation, it indicates that there is a small possibility that there is an abnormal situation where the intermediate shaft is loose and the gap is too large in the vehicle. If the vehicle driving mileage signal exceeds the minimum detection mileage limit value which allows activation, the abnormal condition that the intermediate shaft is loose and the gap is too large is indicated to the vehicle, and the step 2 is entered.
And 2, the steering controller acquires the system state, the vehicle ignition state, the vehicle driving mileage, the vehicle speed, the hand torque of the steering wheel, the state of a steering angle sensor, the current steering wheel angle and a signal value stored in the nonvolatile storage module in a power-off mode of the current electric power steering system.
And 3, when the system state of the electric power steering system is normal and simultaneously meets the conditions that the vehicle speed is less than the maximum vehicle speed set value, the hand torque of the steering wheel is less than or equal to the maximum hand torque set value, the state of the corner sensor is normal, the current steering wheel corner is less than or equal to the maximum corner set value, and the accumulated recorded fault times are less than the minimum alarm times, continuing to perform the step 3 to start detection, wherein the detection time does not exceed the maximum set detection time value, and otherwise, finishing the detection.
In this embodiment, when the steering wheel hand torque exceeds the maximum hand torque set value or the current steering wheel angle exceeds the maximum angle set value, it is determined that the driver has an active steering intention, and the gap detection function is not activated. When the hand torque of the steering wheel is less than or equal to the set value of the maximum hand torque and the current steering wheel angle is less than or equal to the set value of the maximum steering angle, judging that the driver does not have an active steering intention, and starting detection under the condition of simultaneously meeting other conditions, wherein the detection time value is generally 2000 milliseconds.
In this embodiment, the hand torque of the steering wheel is less than or equal to the maximum hand torque set value, and the current steering wheel angle is less than or equal to the maximum steering angle set value, which indicates that the driver does not have an active steering intention.
In this embodiment, the mechanical static friction torque of the pipe column is calibrated by using a real vehicle, and the calibration steps are as follows:
step 1a, a fault part with loose and overlarge gap of the intermediate shaft is installed on a vehicle, the vehicle is statically placed on a flat road surface with low adhesion coefficient, a steering wheel is placed in a middle position, and the steering wheel is in a free state without connecting pipes. Wherein, the flat low-adhesion coefficient road surface is a wet asphalt road surface with a flat test road surface and an adhesion coefficient of about 0.4-0.6.
And 2a, setting the compensation torque as 0, and setting the smoothness factor of the detection torque along with the change of the steering wheel angle as 1.
Step 3a, injecting the initial fixed motor torque as injection torque into a steering wheel, observing whether the angle of the steering wheel changes, and if the steering wheel rotates, gradually reducing the injection torque according to a set torque gradient; if the steering wheel is not rotated, the injection torque is gradually increased according to a set torque gradient. The torque gradient may be set according to actual test requirements, in this example the torque gradient is 0.1Nm.
And 4a, repeating the step 3a until the injection torque critical value which enables the steering wheel to be basically kept still and enables the observation corner signal to be smaller than the set angle is obtained, namely the mechanical static friction torque of the pipe column. The set angle of the observation angle signal can be set according to the actual test requirement, and in the example, the set angle is 0.1 degrees.
In this embodiment, the compensation torque is calibrated by using a real vehicle, and the calibration steps are as follows:
and step 1b, setting the mechanical static friction moment of the pipe column as a calibrated moment value.
And 2b, setting the initial value of the compensation torque as 0Nm, and setting the smoothness factor of the detection torque along with the change of the steering wheel angle as 1.
And 3b, installing a fault part with loose and overlarge gap on the intermediate shaft on the vehicle, placing the vehicle on a flat road surface when the vehicle is static, and placing the steering wheel in a neutral position and in a free state without taking over the steering wheel.
And 4b, injecting detection motor torque leftwards and rightwards respectively, simultaneously gradually increasing a compensation torque value on the basis of an initial value of the compensation torque according to a set torque gradient, observing whether the steering wheel rotates, and recording the angle difference of the steering wheel moving leftwards and rightwards. The torque gradient may be set according to actual test requirements, in this example the torque gradient is 0.1Nm.
And 5b, repeating the step 4b, and taking the critical value when the angle difference of the steering wheel is larger than the set angle as the middle value of the compensation moment. The setting angle of the angle difference of the steering wheel can be set according to the actual test requirement, and in the example, the setting angle is 10 degrees.
And 6b, mounting the non-fault part without loosening the intermediate shaft on the vehicle, placing the vehicle on a flat road in a stationary manner, placing the steering wheel in a middle position, and enabling the steering wheel to rotate within a function activation range.
And 7b, injecting the torque of the detection motor leftwards and rightwards respectively, observing the change of the angle of the steering wheel, and gradually reducing the compensation torque value on the basis of the middle value of the compensation torque according to the set torque gradient. The torque gradient may be set according to actual test requirements, in this example the torque gradient is 0.1Nm.
And 8b, repeating the step 7b, and taking the critical value when the difference value of the angle signals of the steering wheel is smaller than the set angle, namely the compensation moment. The setting angle of the steering wheel angle signal difference can be set according to actual test requirements, and in this example, the setting angle is 2 °.
In this embodiment, a relationship curve of the factor of the change of the detection torque along with the steering wheel angle is shown in fig. 3, the X axis is the steering wheel angle, the Y axis is the detection torque smoothness factor, the curve of the smoothness factor of the detection torque along with the change of the steering wheel angle is calibrated by using a real vehicle, and the calibration steps are as follows:
and step 1c, setting the mechanical static friction torque of the pipe column as a calibrated torque value, setting the compensation torque as a calibrated torque value, and setting the initial values of the smoothness factor curves of the detection torque along with the change of the steering angle of the steering wheel as 1.
And 2c, installing a fault part with loose middle shaft and overlarge gap in the vehicle, standing the vehicle on a flat road surface, placing the steering wheel in the middle position, and holding the steering wheel by both hands in a virtual manner to be in a pipe connection state.
And 3c, injecting the torque of the motor, and observing the gradient of the hand torque of the steering wheel in the process of increasing the rotation angle of the steering wheel from 0 degree to a set angle. The set angle of the steering wheel angle can be set according to actual test requirements, and in this example, the set angle is 1 °.
And 4c, gradually reducing the smoothness factor of the detection torque along with the change of the steering wheel angle according to the set gradient until the gradient of the hand torque of the steering wheel is smaller than the set critical value and the gradient is used as the value of the smoothness factor under the corresponding set angle. The set gradient and the set threshold value can be set according to actual test requirements, in this example, the set gradient is 0.1, and the set threshold value is 0.5Nm/s.
And 5c, repeating the step 3c and the step 4c, obtaining the value of the smoothness factor under the corresponding corner in the process that the steering wheel corner is gradually increased to the maximum corner, and forming a smoothness factor curve of the detection torque changing along with the steering wheel corner according to the values of the smoothness factors under all corners.
When the vehicle speed is within the set range, the slope of the output detection torque is limited according to the curve of the slope limit value of the output detection torque along with the vehicle speed, so that the safety and controllability of the vehicle in the driving process are ensured.
In this embodiment, a curve of the output detection torque slope limit value along with the vehicle speed is shown in fig. 4, an X axis is the vehicle speed, a Y axis is the output detection torque slope limit value, and the curve of the output detection torque slope limit value along with the vehicle speed needs to be calibrated in a real vehicle, wherein the calibration steps are as follows:
step 1d, setting the mechanical static friction torque of the pipe column as a calibrated torque value, setting the compensation torque as a calibrated torque value, setting a smoothness factor curve of the detection torque changing along with the steering wheel angle as a calibrated value, and setting an initial value of a curve of the output detection torque slope limit along with the vehicle speed, wherein the initial value can be set according to actual test requirements, and in the example, the initial value is set to be 10Nm/s.
And 2d, accelerating the vehicle, keeping the vehicle speed at a fixed vehicle speed, injecting and outputting a detection torque, and observing the vehicle offset. The fixed vehicle speed can be set according to actual test requirements, and in the example, the fixed vehicle speed is 10Km/h.
And 3d, if the vehicle offset exceeds the maximum set value, reducing the output detection torque slope value according to the set gradient, if the vehicle offset does not exceed the maximum set value, increasing the output detection torque slope value according to the set gradient until a critical value that the vehicle offset does not exceed the maximum set value is obtained and used as the output detection torque slope limit value under the corresponding vehicle speed. The maximum set value and the set gradient of the vehicle offset can be set according to actual test requirements, in the example, the maximum set value of the vehicle offset is 20cm, and the set gradient is 1Nm/s.
And 4d, repeating the step 2d and the step 3d, obtaining the slope limit value of the output detection torque under the corresponding vehicle speed in the process that the vehicle accelerates to the maximum working set value, and forming a curve of the slope limit value of the output detection torque along with the vehicle speed according to the slope limit values of the output detection torque under all the vehicle speeds.
In this embodiment, the detected torque output algorithm diagram is shown in fig. 5, and the input signals are a steering wheel angle signal, a vehicle speed signal, and the output signals are detected torque signals. The detection output detection torque slope limit value is obtained by interpolating the vehicle speed through a curve of the output detection torque slope limit value calibrated by the real vehicle along with the vehicle speed. The smoothness factor of the detection moment changing along with the steering wheel angle is obtained by interpolating the absolute value of the steering wheel angle through a curve of the detection moment calibrated by a real vehicle and the change factor of the steering wheel angle. The sum of the mechanical static friction moment of the pipe column and the compensation moment is multiplied by the smoothness factor, and finally the detected motor moment is output for motor control through the upper limit and the lower limit boundary after passing through the slope limit value of the torque slope limit value curve.
In this embodiment, the detection torques are output to the left and the right, respectively, and the step of detecting the change of the actual rotation angle of the current steering wheel is as follows:
and step 1f, continuously outputting the detection torque leftwards until the set value of the detection time is reached, and recording the first steering wheel angle at the moment.
And 2f, continuously outputting the detection torque to the right until the set value of the detection time is reached, and recording the angle II of the steering wheel at the moment.
And 3f, calculating the difference value of the first steering wheel angle and the second steering wheel angle.
And 5, if the change of the actual turning angle of the steering wheel exceeds the maximum set value, the loose clearance of the current intermediate shaft is too large, the accumulated failure frequency is increased once, and if the change of the actual turning angle of the steering wheel does not exceed the maximum set value, the loose clearance of the current intermediate shaft is normal, the detection is finished, and the intermediate shaft is not activated in the current ignition cycle. The maximum setting value of the change of the actual turning angle of the steering wheel may be set according to actual test requirements, and in this example, the maximum setting value of the change of the actual turning angle of the steering wheel is 5 °.
In this embodiment, the effective detection is performed only 5 times every fixed kilometer number when the vehicle runs, where the effective detection means that steps 2 to 5 are completely performed, and when the 5 times of effective detection are completed and the fault is not reported, the detection is not performed within the fixed kilometer number.
Referring to fig. 6, step 6, if the accumulated failure times is less than the minimum alarm failure times, the steering system records the failure times and saves the failure times when the steering system is powered off, and the step 3 is continuously executed; if the accumulated failure times reach the minimum alarm failure times, the steering system starts to explode the yellow light in the next ignition period, the yellow light cannot be cleared after being powered off, and the yellow light cannot be cleared until a diagnosis service fault clearing signal is received; if the ignition cycle times of the continuous yellow-explosion lamps reach the maximum yellow-explosion lamp fault times, the steering system starts to explode the red lamp in the next ignition cycle, the red lamp cannot be cleared after being powered off, and the red lamp cannot be cleared until a fault clearing signal of the diagnostic service is received. The minimum alarm failure times and the maximum explosion yellow light failure times can be set according to actual test requirements, and in the embodiment, the minimum alarm failure times and the maximum explosion yellow light failure times are 3 times.
And 7, if the steering system detects that the intermediate shaft is loose and has overlarge clearance and explodes a red light, the steering system reduces the power assistance and maintains the red light state until a diagnosis service fault clearing signal is received, and all faults and fault times are cleared. The proportion of the power-assisted reduction of the steering system can be set according to actual test requirements, and in the embodiment, the power-assisted reduction of the steering system is up to 50% of the power-assisted capacity.
The invention can implement active detection, and can early warn a driver to burst a light and reduce the power when the intermediate shaft of the tubular column type electric power steering system has an abnormal condition of overlarge clearance; the abnormal condition that the gap between the middle shafts is too large can be accurately and effectively detected and early warned on a normal road surface and a low-attachment road surface, so that potential safety hazards such as cross shaft disengagement and the like possibly caused by the too large gap between the cross shafts of the middle shafts under extreme working conditions are reduced, the safe driving of a vehicle is ensured, the safety performance of the whole vehicle is improved, and unnecessary loss of a whole vehicle factory and a client is effectively reduced; when the abnormal condition that the intermediate shaft is loose and has overlarge clearance does not exist, the subjective feeling of a terminal driver is not influenced by active detection, and the safety of vehicle running is controllable after the active detection is activated.
Claims (9)
1. The utility model provides an open clearance detection early warning method of electronic power assisted steering system jackshaft which characterized in that: the method comprises the following steps:
step 1, a steering controller acquires the vehicle driving mileage and judges whether the vehicle driving mileage exceeds a minimum detection mileage limit value which allows activation, if so, the step 2 is continued, and if not, the detection is finished;
step 2, the steering controller acquires the system state of the current electric power steering system, the vehicle ignition state, the vehicle speed, the hand torque of the steering wheel, the state of a steering angle sensor, the current steering wheel steering angle and a signal value stored in a nonvolatile storage module in a power-off mode;
step 3, when the system state of the electric power steering system is normal and simultaneously meets the conditions that the vehicle speed is less than the maximum vehicle speed set value, the hand torque of the steering wheel is less than or equal to the maximum hand torque set value, the state of the corner sensor is normal, the current steering wheel corner is less than or equal to the maximum corner set value, and the accumulated recorded fault times are less than the minimum alarm times, continuing to perform the step 3 to start detection, wherein the detection time does not exceed the maximum set detection time value, otherwise, the detection is finished;
step 4, calculating the detection torque
，
，
Is the mechanical static friction moment of the pipe column,
in order to compensate for the moment of force,
the method comprises the steps that a smoothness factor curve of detection torque changing along with the steering wheel rotation angle is obtained, when the steering wheel is in a middle position, the hand torque of the steering wheel is smaller than or equal to a maximum hand torque set value, and the current steering wheel rotation angle is smaller than or equal to a maximum rotation angle set value, the detection torque is respectively output leftwards and rightwards, and the change of the current actual rotation angle of the steering wheel is detected;
and 5, if the change of the actual turning angle of the steering wheel exceeds the maximum set value, the loose clearance of the current intermediate shaft is too large, the accumulated failure times are increased once, and if the change of the actual turning angle of the steering wheel does not exceed the maximum set value, the loose clearance of the current intermediate shaft is normal, and the detection is finished.
2. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: in the step 1, the minimum detection mileage limit is smaller than the average mileage when the loose gap of the intermediate shaft is detected to be too large in the bench endurance test, and the minimum detection mileage limit can be calibrated.
3. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: in the step 4, the mechanical static friction moment of the pipe column is calibrated by a real vehicle, and the calibrating steps are as follows: step 1a, a fault part with a loose middle shaft and an overlarge gap is arranged on a vehicle, the vehicle is statically placed on a flat road surface with a low adhesion coefficient, a steering wheel is placed in a middle position, and the steering wheel is in a free state without a connecting pipe; step 2a, setting the compensation torque as 0, and setting the smoothness factor of the detection torque along with the change of the steering wheel angle as 1; step 3a, injecting the initial fixed motor torque as injection torque into a steering wheel, observing whether the angle of the steering wheel changes, and gradually reducing the injection torque according to a set torque gradient if the steering wheel rotates; if the steering wheel does not rotate, gradually increasing the injection torque according to a set torque gradient; and 4a, repeating the step 3a until the injection torque critical value which enables the steering wheel to be basically kept still and enables the observation corner signal to be smaller than the set angle is obtained, namely the mechanical static friction torque of the pipe column.
4. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: in step 4, the compensation torque is calibrated by using a real vehicle, and the calibration steps are as follows: step 1b, setting the mechanical static friction moment of the pipe column as a calibrated moment value; step 2b, setting the initial value of the compensation torque as 0Nm, and setting the smoothness factor of the detection torque along with the change of the steering wheel angle as 1; step 3b, a fault part with loose middle shaft and overlarge gap is installed on the vehicle, the vehicle is statically placed on a flat road surface, the steering wheel is placed in the middle position, and the steering wheel is in a free state without connecting pipes; step 4b, injecting detection motor torque leftwards and rightwards respectively, simultaneously gradually increasing a compensation torque value on the basis of an initial value of the compensation torque according to a set torque gradient, observing whether a steering wheel rotates or not, and recording the angle difference of the steering wheel moving leftwards and rightwards; step 5b, repeating the step 4b, and taking a critical value when the angle difference of the steering wheel is larger than a set angle as a compensation moment intermediate value; step 6b, mounting a non-fault part of the intermediate shaft, which is not loosened, on a vehicle, placing the vehicle on a flat road surface in a stationary manner, placing the steering wheel in a middle position, and enabling the steering wheel to rotate within a function activation range; step 7b, injecting detection motor torques leftwards and rightwards respectively, observing the change of the angle of the steering wheel, and simultaneously gradually reducing the compensation torque value on the basis of the middle value of the compensation torque according to the set torque gradient; and 8b, repeating the step 7b, and taking the critical value when the difference value of the angle signals of the steering wheel is smaller than the set angle, namely the compensation moment.
5. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: in step 4, the ride comfort factor curve of the detection torque changing along with the steering wheel angle is calibrated by a real vehicle, and the calibration steps are as follows: step 1c, setting the mechanical static friction torque of the pipe column as a calibrated torque value, setting the compensation torque as a calibrated torque value, and setting the initial values of the smoothness factor curves of the detection torque along with the change of the steering angle of the steering wheel as 1; step 2c, a fault part with loose middle shaft and overlarge gap is installed on the vehicle, the vehicle is statically placed on a flat road surface, the steering wheel is placed in the middle position, and the steering wheel is in a pipe connection state when being held by both hands; step 3c, injecting motor torque, and observing the gradient of hand torque of the steering wheel in the process of increasing the turning angle of the steering wheel from 0 degree to a set angle; step 4c, gradually reducing the smoothness factor of the detection torque along with the change of the steering wheel angle according to the set gradient until the gradient of the hand torque of the steering wheel is smaller than the set critical value and the gradient is used as the value of the smoothness factor under the corresponding set angle; and 5c, repeating the step 3c and the step 4c, obtaining the value of the smoothness factor under the corresponding corner in the process that the steering wheel corner is gradually increased to the maximum corner, and forming a smoothness factor curve of the detection torque changing along with the steering wheel corner according to the values of the smoothness factors under all corners.
6. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: and 4, performing boundary limit protection on the output detection torque and monitoring the vehicle speed, reducing the output detection torque to 0 when the vehicle speed is greater than a maximum set value, and limiting the slope of the output detection torque according to a curve of the slope limit of the output detection torque along with the vehicle speed when the vehicle speed is in a set range, so as to ensure the safety and controllability of the vehicle in the driving process.
7. The method for detecting and warning the loosening gap of the intermediate shaft of the electric power steering system according to claim 6, wherein the method comprises the following steps: the curve of the output detection torque slope limit value along with the vehicle speed needs real vehicle calibration, and the calibration steps are as follows: step 1d, setting the mechanical static friction torque of the pipe column as a calibrated torque value, setting the compensation torque as a calibrated torque value, setting a smoothness factor curve of the detection torque changing along with the steering wheel angle as a calibrated value, and setting an initial value of a curve of the output detection torque slope limit along with the vehicle speed; step 2d, accelerating the vehicle, keeping the vehicle speed at a fixed speed, injecting and outputting a detection torque, and observing the vehicle offset; step 3d, if the vehicle offset exceeds the maximum set value, reducing the output detection torque slope value according to the set gradient, if the vehicle offset does not exceed the maximum set value, increasing the output detection torque slope value according to the set gradient until a critical value that the vehicle offset does not exceed the maximum set value is obtained and used as the output detection torque slope limit value under the corresponding vehicle speed; and 4d, repeating the step 2d and the step 3d, obtaining the slope limit value of the output detection torque under the corresponding vehicle speed in the process that the vehicle accelerates to the maximum working set value, and forming a curve of the slope limit value of the output detection torque along with the vehicle speed according to the slope limit values of the output detection torque under all the vehicle speeds.
8. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: in the step 4, the detection torques are respectively output to the left and the right, and the step of detecting the change of the actual rotation angle of the current steering wheel is as follows: step 1f, continuously outputting the detection torque to the left until a detection time set value is reached, and recording a first steering wheel angle at the moment; step 2f, continuously outputting the detection torque to the right until a detection time set value is reached, and recording a second steering wheel angle at the moment; and 3f, calculating the difference value between the first steering wheel angle and the second steering wheel angle.
9. The method for detecting and warning the loosening clearance of the intermediate shaft of the electric power steering system according to claim 1, characterized in that: step 6, if the accumulated failure times is less than the minimum alarm failure times, the steering system records the failure times, saves the failure times when the steering system is powered off, and continuously returns to execute the step 3; if the accumulated failure times reach the minimum alarm failure times, the steering system starts to explode yellow light in the next ignition period; if the ignition cycle times of the continuous yellow-explosion lamps reach the maximum yellow-explosion lamp failure times, the steering system starts to explode red lamps in the next ignition cycle;
and 7, if the steering system detects that the intermediate shaft is loose and has overlarge clearance and explodes a red light, the steering system reduces the power assistance and maintains the red light state until a diagnosis service fault clearing signal is received, and all faults and fault times are cleared.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0939807A (en) * | 1995-07-25 | 1997-02-10 | Honda Motor Co Ltd | Electric power steering device |
| CN104864834A (en) * | 2015-05-21 | 2015-08-26 | 安徽江淮汽车股份有限公司 | Automotive steering intermediate shaft torsion gap detection device |
| KR20170138295A (en) * | 2016-06-07 | 2017-12-15 | 한국생산기술연구원 | Apparatus and method for measuring torsional lash of intermediate shaft assembly |
| CN109533011A (en) * | 2018-10-22 | 2019-03-29 | 清华大学 | A kind of commercial vehicle electric auxiliary steering system control method |
| CN113847422A (en) * | 2021-09-18 | 2021-12-28 | 陕西法士特齿轮有限责任公司 | Torque control method and system of AMT intermediate shaft brake |
| CN114348112A (en) * | 2021-12-27 | 2022-04-15 | 博世华域转向***有限公司 | Automobile steering control method suitable for semi-automatic driving scene |
-
2022
- 2022-08-26 CN CN202211031675.3A patent/CN115388834A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0939807A (en) * | 1995-07-25 | 1997-02-10 | Honda Motor Co Ltd | Electric power steering device |
| CN104864834A (en) * | 2015-05-21 | 2015-08-26 | 安徽江淮汽车股份有限公司 | Automotive steering intermediate shaft torsion gap detection device |
| KR20170138295A (en) * | 2016-06-07 | 2017-12-15 | 한국생산기술연구원 | Apparatus and method for measuring torsional lash of intermediate shaft assembly |
| CN109533011A (en) * | 2018-10-22 | 2019-03-29 | 清华大学 | A kind of commercial vehicle electric auxiliary steering system control method |
| CN113847422A (en) * | 2021-09-18 | 2021-12-28 | 陕西法士特齿轮有限责任公司 | Torque control method and system of AMT intermediate shaft brake |
| CN114348112A (en) * | 2021-12-27 | 2022-04-15 | 博世华域转向***有限公司 | Automobile steering control method suitable for semi-automatic driving scene |
Non-Patent Citations (1)
| Title |
|---|
| 曹艳玲;曹增;徐立友;: "电动汽车路面转向电机稳定性控制仿真研究", 计算机仿真, no. 09, 15 September 2017 (2017-09-15) * |
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