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CN-117141579-B - Calculation method based on EPS angle following control

CN117141579BCN 117141579 BCN117141579 BCN 117141579BCN-117141579-B

Abstract

Compared with the prior art, the invention solves the problems of too slow response time and response clamping stagnation under small angles and small rotating speeds, realizes the requirements of a full vehicle speed section on EPS corner following performance, and simultaneously can realize the technical effects of no shake of low vehicle speed, timely high vehicle speed following and shake reduction of uneven pavement.

Inventors

  • GUAN BINBIN
  • ZHOU WEI
  • Su Zhejun
  • SUN GUOSHUAI
  • GAO SENQI
  • HU HUI
  • FAN ZHIYONG
  • ZHAO WEN
  • YING ZE
  • ZHAO WEIJIE

Assignees

  • 博世华域转向系统有限公司

Dates

Publication Date
20260508
Application Date
20230830

Claims (9)

  1. 1. A calculation method based on EPS angle following control is characterized by comprising a target angular velocity calculation method and a target torque calculation method, wherein the target angular velocity calculation method comprises the following steps of 1, acquiring a target angle AngReq and an activation request ActReq sent by an advanced driving assistance system by an EPS control unit, acquiring an EPS current angle CurrentAng and a current vehicle speed, 2, performing signal processing on a target angle AngReq to obtain a target angle TARGETANG, 3, calculating an angle difference DeltaAng = TARGETANG-CurrentAng, 4, performing real vehicle debugging according to the angle difference DeltaAng and the current vehicle speed to determine a target angular velocity closed-loop control parameter rule base, 5, determining a small angle boundary value SmallAngComp to be compensated through real vehicle debugging, 6, performing real vehicle debugging according to the angle difference DeltaAng and the current vehicle speed to determine a small angle gain Ps parameter rule base, 7, judging whether the angle difference DeltaAng is smaller than the small angle boundary value SmallAngComp, if yes, calculating a calculated value +small angle gain Ps obtained through closed-loop control of the target angular velocity TARGETANGSPD = DeltaAng, and if not, calculating a calculated value obtained through closed-loop control of the target angular velocity= TARGETANGSPD = DeltaAng; The target torque calculation comprises the steps of 8, acquiring an activation request ActReq and a torque limit TorqLim sent by an advanced driving assistance system, acquiring an EPS current angle CurrentAng, acquiring a current vehicle speed and a steering wheel angular acceleration aRotAcceleration by an EPS control unit, 9, judging whether the activation request ActReq is activated or not by the EPS control unit, if not, calculating a target torque output 0, if so, closing active return, continuing 10, performing signal processing on a target angular velocity TARGETANGSPD to obtain a filtered target angular velocity TARGETANGSPDFILT, performing filter processing on an actual angular velocity CurrentAngSpd to obtain a filtered actual angular velocity CurrentAngSpdFilt, 11, calculating an angular velocity difference DELTAANGSPD = TARGETANGSPDFILT-CurrentAngSpdFilt, 12, performing real-vehicle debugging according to the angular velocity difference DELTAANGSPD and the current vehicle speed, determining a target torque closed-loop control parameter rule base, 13, determining a target torque attenuation coefficient Pc parameter rule base by real-vehicle debugging according to the steering angular acceleration change frequency, judging whether the steering angular acceleration change frequency is larger than F, if the calculated target angular velocity is larger than the calculated target angular velocity, and obtaining a final torque value of DELTAANGSPD, and if the calculated target torque value is larger than the calculated target angular velocity is no longer than the calculated target torque value, and the target torque value is calculated by the closed-loop control parameter rule base, and the final torque value is calculated to obtain a target torque value of the closed-loop control value of 8647=3724.
  2. 2. The method of claim 1, wherein the step of performing signal processing on the target angle AngReq, the step of performing signal processing on the target angular velocity TARGETANGSPD, and the step of performing signal processing on the target torque TargetTorq include clipping and filtering.
  3. 3. The calculation method based on EPS angle follow-up control according to claim 1, wherein the step 4 comprises the steps of 4a, presetting a group of closed-loop control parameters according to different angle differences DeltaAng under the condition of whole vehicle debugging, obtaining a target angular velocity TARGETANGSPD through closed-loop control, 4b, correcting preset closed-loop parameter values according to the value of the target angular velocity TARGETANGSPD until the obtained target angular velocity TARGETANGSPD meets the performance requirement, and 4c, recording the corrected closed-loop parameter values and storing the corrected closed-loop parameter values in a target angular velocity closed-loop control parameter rule library.
  4. 4. The calculation method based on EPS angle following control according to claim 1, wherein the step 5 comprises the steps of 5a, under the whole vehicle debugging working condition, the advanced driving assistance system sends different target angles AngReq under different vehicle speeds, observing angle differences, response time and angle differences DeltaAng between the current EPS angle CurrentAng and the target angle AngReq, and 5b, setting a small angle boundary value SmallAngComp according to performance requirements.
  5. 5. The calculation method based on EPS angle following control according to claim 1, wherein the step 6 comprises the steps of 6a, under the condition of whole vehicle debugging, respectively obtaining small angle boundary values to be compensated, 6b, setting a group of difference lookup tables, obtaining target angular velocity gain values through angle difference DeltaAng and lookup tables, 6c, correcting the preset target angular velocity gain values according to the actual target angular velocity values until the obtained target angular velocity meets performance requirements, and 6d, recording the corrected target angular velocity gain values and storing the corrected target angular velocity gain values into a small angle gain Ps parameter rule base.
  6. 6. The calculation method based on EPS angle following control according to claim 1, wherein the step 12 comprises the steps of 12a, presetting a group of closed-loop control parameters according to different angular speed differences DELTAANGSPD under the condition of whole vehicle debugging, obtaining target torque TargetTorq through closed-loop control, 12b, driving a steering wheel to rotate by a corresponding angle according to the target torque TargetTorq, 12c, correcting preset closed-loop parameter values according to the following condition of a current angle CurrentAng and a target angle TARGETANG until the obtained current angle CurrentAng meets performance requirements, and 12d, recording the corrected closed-loop parameter values and storing the corrected closed-loop parameter values into a target torque closed-loop control parameter rule library.
  7. 7. The method of claim 6, wherein the following conditions include response time, steady state error, and overshoot performance requirements.
  8. 8. The calculation method based on EPS angle follow control according to claim 1, wherein the step 13 comprises the steps of calculating the number n of repeated alternation of detecting an angular acceleration value larger than a and smaller than-a or smaller than a and larger than a within a deltat time, step 13a, calculating a steering angle acceleration change frequency=n/deltat, if the steering angle acceleration change frequency=0, the road surface condition is normal, if the steering angle acceleration change frequency >0, the road surface condition is bumpy, step 13c, if the steering angle acceleration change frequency > F, the steering angle acceleration change frequency duration < t1, the target torque attenuation coefficient pc=pc1, if the steering angle acceleration change frequency > F, the steering angle acceleration change frequency duration > t1 and < t2, the target torque attenuation coefficient pc=pc2, if the steering angle acceleration change frequency > F, the steering angle acceleration change frequency duration > t2 and < t3, the target torque attenuation coefficient pc=pc3.
  9. 9. The method of claim 8, wherein deltT, a, F, t, pc1, t2, pc2, t3, and Pc3 are calibration values determined by real vehicle debugging.

Description

Calculation method based on EPS angle following control Technical Field The invention relates to the technical field of electric power steering, in particular to a calculation method based on EPS angle following control. Background With the development of intelligent driving, people have increasingly high requirements on driving assistance functions, including lane centering control and lane line deviation control. The development of these technologies requires a steering execution system typified by an EPS system to execute a steering command. Therefore, the control strategy capable of enabling the rotation angle to quickly and accurately follow the target angle sent by the upper computer has very important significance. Because the whole vehicle running environment is complex and changeable, the influence factors on the corner following control performance are many, including the vehicle speed, the road surface and the like. The requirements on the rotation angle following performance are different under different vehicle speeds, the low speed can often carry out large-angle high-rotation-speed operation such as emergency avoidance, turning around, lane changing and the like, and the high-speed running is often not allowed to carry out large-angle high-rotation-speed operation. Therefore, the maximum allowable angle and rotation speed are different at different vehicle speeds. Because EPS basic assistance tends to be larger than that of the vehicle at low speed, performances of the vehicle at different speeds tend to be different, excessive shaking and vibration correction tend to occur at low speed, and following delay and the like tend to occur at high speed. Different road surface excitations can produce torsion bar deformation, and then influence the stability of angle control, usually appear when crossing the pothole road surface, EPS shake violently. Besides the influence of the speed and the road surface, the motor inertia is large, and when the motor is regulated by small angle difference, the basic power assisting is smaller, so that the control performance is often poor, and the response time is generally slow, and clamping stagnation and the like are easy to occur in the response process. Therefore, a calculation method based on EPS angle following control needs to be designed to solve the problems of too slow response time and response jamming under small angles and small rotation speeds. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a calculation method based on EPS angle following control, so as to solve the problems of too slow response time and response clamping stagnation under small angles and small rotating speeds. In order to achieve the aim, the invention provides a calculation method based on EPS angle following control, which comprises a target angular velocity calculation method and a target torque calculation method, wherein the target angular velocity calculation method comprises the following steps of step 1, obtaining a target angle AngReq and an activation request ActReq sent by an advanced driving auxiliary system by an EPS control unit, obtaining an EPS current angle CurrentAng and a current vehicle speed, step 2, carrying out signal processing on the target angle AngReq to obtain a target angle TARGETANG, step 3, calculating an angle difference DeltaAng = TARGETANG-CurrentAng, step 4, carrying out real vehicle debugging according to the angle difference DeltaAng and the current vehicle speed to determine a target angular velocity closed-loop control parameter rule base, step 5, determining a small angle boundary value SmallAngComp needing to be compensated through real vehicle debugging, step 6, carrying out real vehicle debugging according to the angle difference DeltaAng and the current vehicle speed to determine a small angle gain Ps parameter rule base, step 7, judging whether the angle difference DeltaAng is smaller than the small angle boundary value SmallAngComp, if the angle difference is smaller than the small angle boundary value SmallAngComp, calculating a calculated value of the target angular velocity TARGETANGSPD = DeltaAng through closed-loop control, and if the calculated value is not, carrying out real vehicle debugging according to the angle difference DeltaAng and the calculated value through closed-loop control to obtain the closed-loop control value. Step 8, the EPS control unit obtains an activation request ActReq and a torque limit value TorqLim sent by the advanced driving assistance system, obtains the EPS current angle CurrentAng, obtains the current vehicle speed and the steering wheel angular acceleration aRotAcceleration; step 9, the EPS control unit judges whether the activation request ActReq is activated or not, if not, the target torque output 0 is calculated, if yes, the active return is closed, and the step 10 is continued, step 10, the target angular velocity TARGETANGSPD is subjected to