Steering wheel torque control method, device, computer equipment and readable storage medium

Abstract

The present application relates to a steering wheel torque control method, device, computer equipment and readable storage medium. The method comprises: obtaining the target steering wheel angle carried in the steering wheel angle request instruction corresponding to the current moment of the target vehicle; obtaining the feedforward control instruction corresponding to the current moment according to the target steering wheel angle; determining the PID parameters associated with the current moment according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, and determining the feedback control instruction corresponding to the current moment according to the PID parameters and the deviation; generating the steering wheel torque control instruction for the current moment based on the feedforward control instruction and the feedback control instruction. The method can avoid the problem of decreased control instruction accuracy caused by inaccurate model and incomplete model coverage, and obtain accurate steering wheel torque control instructions, thereby improving the control accuracy of the steering wheel torque.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a steering wheel torque control method, device, computer equipment, computer-readable storage medium and computer program product. Background Art

[0002] In vehicle lateral control, after the upper-level control algorithm gives the steering wheel angle, the vehicle needs to respond to the corresponding steering wheel angle command requirements to achieve vehicle path tracking control. In actual applications, at high speeds (usually greater than 30kph), the vehicle chassis provides a torque command interface, so it is necessary to convert the steering wheel angle request command of the upper-level lateral control into a torque command request, and finally send it to the chassis for execution.

[0003] Traditional technology mainly achieves steering wheel torque control through dynamic modeling. However, the control process of steering wheel angle to torque will change with the steering wheel angle, vehicle speed, etc. Dynamic modeling cannot fully cover various situations, resulting in a decrease in the accuracy of steering wheel torque, which is not conducive to improving the control accuracy of steering wheel torque. Summary of the invention

[0004] Based on this, it is necessary to provide a steering wheel torque control method, device, computer equipment, computer readable storage medium and computer program product that can improve the control accuracy of steering wheel torque in response to the above technical problems.

[0005] In a first aspect, the present application provides a steering wheel torque control method, comprising:

[0006] Obtaining a target steering wheel angle carried in a steering wheel angle request instruction corresponding to the current moment of the target vehicle;

[0007] Obtaining a feedforward control instruction corresponding to the current moment according to the target steering wheel angle;

[0008] Determine the PID parameter associated with the current moment according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, and determine the feedback control instruction corresponding to the current moment according to the PID parameter and the deviation;

[0009] Based on the feedforward control instruction and the feedback control instruction, a steering wheel torque control instruction for the current moment is generated; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle.

[0010] In one embodiment, obtaining the feedforward control instruction corresponding to the current moment according to the target steering wheel angle includes:

[0011] Obtaining a preset steering angle torque mapping relationship; the steering angle torque mapping relationship is used to characterize the corresponding relationship between the steering wheel angle and the steering wheel torque;

[0012] Obtaining the reference torque corresponding to the current moment according to the target steering wheel angle and the angle-torque mapping relationship;

[0013] Acquire the speed of the target vehicle at the current moment, and obtain a speed compensation coefficient at the current moment according to the speed;

[0014] The reference torque is corrected by using the vehicle speed compensation coefficient to obtain a correction torque corresponding to the current moment, and a feedforward control command corresponding to the current moment is generated based on the correction torque.

[0015] In one embodiment, obtaining a preset angle torque mapping relationship includes:

[0016] Determine the steering wheel torque control command corresponding to the sample steering wheel angle according to the sample PID parameters;

[0017] determining an actual steering angle corresponding to the sample steering wheel angle according to a steering wheel torque control instruction corresponding to the sample steering wheel angle;

[0018] adjusting the sample PID parameter according to a deviation between the sample steering wheel angle and an actual angle corresponding to the sample steering wheel angle, and returning to the step of determining the steering wheel torque control instruction corresponding to the sample steering wheel angle until the sample steering wheel angle matches the actual angle corresponding to the sample steering wheel angle;

[0019] In a case where the sample steering wheel angle and the actual steering angle corresponding to the sample steering wheel angle match, the angle-torque mapping relationship is determined according to the sample steering wheel angle and the steering wheel torque control instruction corresponding to the sample steering wheel angle.

[0020] In one embodiment, the vehicle speed compensation coefficient is obtained based on a preset vehicle speed coefficient mapping relationship and the vehicle speed; the vehicle speed coefficient mapping relationship is used to characterize the corresponding relationship between the vehicle speed and the vehicle speed compensation coefficient; before obtaining the vehicle speed compensation coefficient at the current moment according to the vehicle speed, it also includes:

[0021] Acquire the rotation angle torque mapping relationship;

[0022] According to the sample steering wheel angles at different vehicle speeds and the angle-torque mapping relationship, a reference torque corresponding to the sample steering wheel angles at different vehicle speeds is obtained;

[0023] The vehicle speed coefficient mapping relationship is determined according to the reference torque corresponding to the sample steering wheel angles at the different vehicle speeds and the different vehicle speeds.

[0024] In one embodiment, determining the PID parameter associated at the current moment according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle includes:

[0025] Obtaining a quantization mapping result of a turning angle deviation corresponding to the deviation in a preset quantization domain; the preset quantization domain includes a plurality of fuzzy parameters;

[0026] Determine the PID parameter deviation quantization mapping result in the preset quantization domain according to the quantization mapping result of the steering angle deviation and the preset fuzzy rule; the fuzzy rule is used to characterize the correspondence between the first fuzzy parameter corresponding to each steering angle deviation and the second fuzzy parameter corresponding to the PID parameter deviation;

[0027] Determine the parameter adjustment amount according to the product between the PID parameter deviation quantization mapping result and the preset PID parameter change maximum value;

[0028] The PID parameters are determined according to the preset nominal PID parameters and the parameter adjustment amount.

[0029] In one embodiment, determining the PID parameter deviation quantization mapping result in the preset quantization domain according to the steering angle deviation quantization mapping result and the preset fuzzy rule includes:

[0030] Determining the degree of membership of the corner deviations corresponding to the first fuzzy parameters according to the corner deviation quantization mapping result;

[0031] According to the membership information of each steering angle deviation and the preset fuzzy rule, the PID parameter deviation quantization mapping result is obtained.

[0032] In one embodiment, determining the angle deviation membership information corresponding to each of the first fuzzy parameters according to the angle deviation quantization mapping result includes:

[0033] Obtaining a membership function corresponding to each of the first fuzzy parameters;

[0034] Obtaining, according to the quantization mapping result of the turning angle deviation and the membership function of each of the first fuzzy parameters, the turning angle deviation membership information corresponding to each of the first fuzzy parameters;

[0035] The step of obtaining the PID parameter deviation quantization mapping result according to the steering angle deviation membership information and the preset fuzzy rule includes:

[0036] According to the preset fuzzy rule, obtaining the second fuzzy parameter corresponding to each of the first fuzzy parameters;

[0037] The PID parameter deviation quantization mapping result is obtained according to the steering angle deviation membership information corresponding to each of the first fuzzy parameters and the second fuzzy parameters corresponding to each of the first fuzzy parameters.

[0038] In a second aspect, the present application further provides a steering wheel torque control device, comprising:

[0039] Angle acquisition module, used to acquire the target steering wheel angle carried in the steering wheel angle request instruction corresponding to the current moment of the target vehicle;

[0040] A feedforward determination module, used to obtain a feedforward control instruction corresponding to the current moment according to the target steering wheel angle;

[0041] A feedback determination module, configured to determine a PID parameter associated with the current moment according to a deviation between an actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, and determine a feedback control instruction corresponding to the current moment according to the PID parameter and the deviation;

[0042] The torque control module is used to generate a steering wheel torque control instruction for the current moment based on the feedforward control instruction and the feedback control instruction; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle.

[0043] In a third aspect, the present application further provides a computer device, wherein the computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the above method are implemented.

[0044] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0045] In a fifth aspect, the present application further provides a computer program product, wherein the computer program product comprises a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0046] The above-mentioned steering wheel torque control method, device, computer equipment, computer-readable storage medium and computer program product obtain the target steering wheel angle carried in the steering wheel angle request instruction corresponding to the current moment of the target vehicle, thereby timely and accurately obtaining the corresponding steering wheel angle based on the angle request instruction at the current moment; according to the target steering wheel angle, the corresponding feedforward control instruction at the current moment is obtained, thereby obtaining the accurate feedforward control instruction corresponding to the current moment based on the target steering wheel angle, and providing a basis for subsequently generating a steering wheel torque control instruction in combination with the feedforward control instruction; according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, the PID parameters associated with the current moment are determined, and according to the PID parameters and the deviation, the feedback control instruction corresponding to the current moment is determined, thereby obtaining an accurate feedback control instruction based on the difference between the actual steering wheel angle at the current moment and the target steering wheel angle and the corresponding PID parameters; Based on the feedforward control instruction and the feedback control instruction, a steering wheel torque control instruction for the current moment is generated; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle, so as to accurately generate the steering wheel torque control instruction at the current moment in combination with the feedforward control instruction and the feedback control instruction, so as to control the steering wheel angle torque of the vehicle based on the steering wheel torque control instruction at the current moment, and can determine the accurate feedforward instruction based on the steering wheel angle carried in the angle request instruction at the current moment, and determine the accurate feedback instruction based on the actual angle at the current moment and the corresponding PID parameters, and generate the control instruction for controlling the steering wheel torque at the current moment in combination with the feedforward instruction and the feedback instruction, without the need for dynamic modeling, avoiding the problem of reduced accuracy of the control instruction due to inaccurate modeling and incomplete model coverage of the scene, and obtaining accurate steering wheel torque control instructions, thereby improving the control accuracy of the steering wheel torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 is a schematic flow chart of a steering wheel torque control method in one embodiment;

[0049] Figure 2 A schematic diagram of a steering wheel torque control method based on a fuzzy PID algorithm in one embodiment;

[0050] Figure 3A schematic diagram of a torque command calibration in one embodiment;

[0051] Figure 4 is a schematic diagram of a calibration process in one embodiment;

[0052] Figure 5 A schematic diagram of a torque control based on fuzzy PID in one embodiment;

[0053] Figure 6 is a schematic diagram of a NB membership function in one embodiment;

[0054] Figure 7 is a schematic diagram of an NM membership function in one embodiment;

[0055] Figure 8 is a schematic diagram of a fuzzy parameter membership function set in one embodiment;

[0056] Fig. 9 A schematic diagram of solving feedback control in one embodiment;

[0057] Fig.10 is a structural block diagram of a steering wheel torque control device in one embodiment;

[0058] Fig.11 The figure is a diagram of the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0060] In an exemplary embodiment, Figure 1 As shown, a steering wheel torque control method is provided, which is described by taking the method applied to a vehicle-mounted controller as an example, and includes the following steps S102 to S108. Among them:

[0061] Step S102, obtaining a target steering wheel angle carried in a steering wheel angle request instruction of the target vehicle corresponding to the current moment.

[0062] Among them, the steering wheel angle request instruction may refer to a command for controlling the steering wheel angle of the target vehicle. In actual applications, during vehicle lateral control, the vehicle may determine the steering wheel angle based on an upper-level control algorithm and generate a steering wheel angle request instruction. The vehicle may achieve vehicle path tracking control by responding to the corresponding steering wheel angle request instruction.

[0063] Among them, the target steering wheel angle may refer to the information carried in the steering wheel angle request instruction for controlling the steering wheel angle. In actual applications, the target steering wheel angle may refer to the angle that the steering wheel is required to have. For example: if the steering wheel angle at time t1 is θ1, and the target steering wheel angle is θ2, then at time t2 after the steering wheel angle of the vehicle is controlled based on the target steering wheel angle θ2, the steering wheel angle of the vehicle is θ2.

[0064] As an example, in vehicle lateral control, the target vehicle can determine the target steering wheel angle at the current moment based on a preset upper-level control algorithm, and then the target vehicle can generate a steering wheel angle request instruction corresponding to the current moment based on the target steering wheel angle at the current moment. In order to control the steering wheel torque, the on-board controller can obtain the steering wheel angle request instruction of the target vehicle at the current moment, and determine the target steering wheel angle carried in the steering wheel angle request instruction of the target vehicle at the current moment by parsing the steering wheel angle request instruction of the target vehicle at the current moment.

[0065] Step S104, obtaining a feedforward control instruction corresponding to the current moment according to the target steering wheel angle.

[0066] The feedforward control instruction may refer to a command for controlling the steering wheel torque of the target vehicle based on the target steering wheel angle. In practical applications, the feedforward control instruction may be used as a feedforward torque instruction.

[0067] As an example, the vehicle-mounted controller can first determine the torque corresponding to the target steering wheel angle based on the target steering wheel angle carried in the steering wheel angle request instruction of the target vehicle corresponding to the current moment, and then the vehicle-mounted controller can generate a feedforward control instruction corresponding to the current moment based on the torque corresponding to the target steering wheel angle.

[0068] Step S106, determining the PID parameters associated at the current moment according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, and determining the feedback control instructions corresponding to the current moment according to the PID parameters and the deviation.

[0069] The actual steering wheel angle may refer to information representing the real / actual steering wheel angle of the target vehicle at the current moment.

[0070] Among them, PID parameters can refer to information that characterizes the parameters of the PID controller. In practical applications, PID parameters can include the proportional parameter K p , integration parameter K i and the differential parameter K dPID can refer to proportional-integral-differential. PID control can adjust the output of the controlled system according to the current error value of the system (the difference between the expected value and the actual measured value) by using the three calculation links of proportion, integration and differentiation to achieve the purpose of precise control.

[0071] Among them, the feedback control instruction may refer to a command for controlling the steering wheel torque of the target vehicle based on the target steering wheel angle and the actual steering wheel angle. In actual applications, the feedback control instruction may be used as a feedback instruction, and the feedback instruction may control the steering wheel torque based on the error between the actual steering wheel angle and the target steering wheel angle.

[0072] As an example, the on-board controller can perform feedback control on the steering wheel torque based on PID control. In actual applications, after determining the feedforward control instruction corresponding to the current moment based on the target steering wheel angle, the on-board controller can obtain the actual steering wheel angle of the target vehicle at the current moment through the sensor, and calculate the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle. Then, the on-board controller can adjust the PID parameters of the PID controller (such as preset PID parameters or PID parameters of the PID controller in the time period before the current moment) based on the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, thereby determining the PID parameters associated at the current moment. Afterwards, the on-board controller can determine the torque corresponding to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle based on the PID parameters associated at the current moment and the PID controller, and generate the feedback control instruction corresponding to the current moment according to the torque corresponding to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle.

[0073] Step S108, generating a steering wheel torque control instruction for the current moment based on the feedforward control instruction and the feedback control instruction; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle.

[0074] The steering wheel torque control instruction may refer to information for instructing the target vehicle to control the steering wheel angle torque of the target vehicle.

[0075] As an example, the vehicle-mounted controller can calculate the target steering wheel torque corresponding to the current moment based on the sum / difference between the torque value corresponding to the feedforward control instruction and the torque value corresponding to the feedback control instruction. The vehicle-mounted controller can then generate a steering wheel torque control instruction for the current moment based on the target steering wheel torque. The steering wheel torque control instruction can be sent to the chassis for execution, thereby controlling the steering wheel torque of the vehicle.

[0076] In the above-mentioned steering wheel torque control method, by obtaining the target steering wheel angle carried in the steering wheel angle request instruction corresponding to the target vehicle at the current moment, the corresponding steering wheel angle is accurately obtained in time based on the angle request instruction at the current moment; according to the target steering wheel angle, the feedforward control instruction corresponding to the current moment is obtained, so as to obtain the accurate feedforward control instruction corresponding to the current moment based on the target steering wheel angle, providing a basis for the subsequent generation of steering wheel torque control instructions in combination with the feedforward control instructions; according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, the PID parameters associated with the current moment are determined, and according to the PID parameters and the deviation, the feedback control instruction corresponding to the current moment is determined, so as to obtain the accurate feedback control instruction based on the difference between the actual steering wheel angle at the current moment and the target steering wheel angle and the corresponding PID parameters; based on the feedforward control instruction and the feedback control instruction The steering wheel torque control instruction is used to generate a steering wheel torque control instruction for the current moment; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle, thereby combining the feedforward control instruction and the feedback control instruction to accurately generate the steering wheel torque control instruction at the current moment, so as to control the steering wheel angle torque of the vehicle based on the steering wheel torque control instruction at the current moment, and can determine an accurate feedforward instruction based on the steering wheel angle carried in the angle request instruction at the current moment, and at the same time determine an accurate feedback instruction based on the actual angle at the current moment and the corresponding PID parameters, and generate a control instruction for controlling the steering wheel torque at the current moment in combination with the feedforward instruction and the feedback instruction, without the need for dynamic modeling, avoiding the problem of reduced accuracy of the control instruction due to inaccurate modeling and incomplete model coverage of the scene, and obtaining an accurate steering wheel torque control instruction, thereby improving the control accuracy of the steering wheel torque.

[0077] In some embodiments, a feedforward control instruction corresponding to the current moment is obtained according to the target steering wheel angle, including: obtaining a preset angle-torque mapping relationship; the angle-torque mapping relationship is used to characterize the correspondence between the steering wheel angle and the steering wheel torque; according to the target steering wheel angle and the angle-torque mapping relationship, a reference torque corresponding to the current moment is obtained; the speed of the target vehicle at the current moment is obtained, and a speed compensation coefficient at the current moment is obtained according to the speed; the reference torque is corrected using the speed compensation coefficient to obtain a corrected torque corresponding to the current moment, and a feedforward control instruction corresponding to the current moment is generated based on the corrected torque.

[0078] Among them, the angle-torque mapping relationship may refer to information used to characterize the corresponding relationship between the steering wheel angle and the steering wheel torque. In practical applications, the angle-torque mapping relationship may be expressed as T=f(θ), wherein T may represent the steering wheel torque and θ may represent the steering wheel angle.

[0079] Among them, the reference torque may refer to the torque corresponding to the target steering wheel angle determined based on the angle-torque mapping relationship. In actual applications, the torque corresponding to any steering wheel angle determined based on the angle-torque mapping relationship may be used as the reference torque corresponding to the steering wheel angle.

[0080] The vehicle speed may refer to information representing the speed of the vehicle.

[0081] The vehicle speed compensation coefficient may refer to information used to adjust / correct / calibrate the reference torque based on the vehicle speed. In practical applications, each vehicle speed may have a corresponding vehicle speed compensation coefficient, which may be expressed as K v .

[0082] The corrected torque may refer to a torque obtained by correcting the reference torque using a vehicle speed compensation coefficient.

[0083] As an example, the steering wheel has nonlinear characteristics, and the torque required to maintain balance when the steering wheel is turned to different steering wheel angles is not the same. Therefore, there is a corresponding relationship between the steering wheel angle and the steering wheel torque. The on-board controller can first obtain a preset angle torque mapping relationship, which can characterize the corresponding relationship between the steering wheel angle and the steering wheel torque. Then the on-board controller can differ the target steering wheel angle in the angle torque mapping relationship, and use the steering wheel torque corresponding to the target steering wheel angle in the angle torque mapping relationship as the reference torque corresponding to the current moment. Under the same steering wheel angle, the steering wheel angle values ​​at different vehicle speeds are also different. At this time, the on-board controller can obtain the speed of the target vehicle at the current moment, and determine the speed compensation coefficient at the current moment according to the speed. Then the on-board controller can use the speed compensation coefficient to correct the reference torque to obtain the corrected torque corresponding to the current moment. For example, the on-board controller can use the product of the speed compensation coefficient and the reference torque as the corrected torque corresponding to the current moment. Then the on-board controller can generate the feedforward control instruction corresponding to the current moment based on the corrected torque.

[0084] In this embodiment, a preset angle-torque mapping relationship is obtained; the angle-torque mapping relationship is used to characterize the correspondence between the steering wheel angle and the steering wheel torque; according to the target steering wheel angle and the angle-torque mapping relationship, a reference torque corresponding to the current moment is obtained; the speed of the target vehicle at the current moment is obtained, and the speed compensation coefficient at the current moment is obtained according to the vehicle speed; the reference torque is corrected using the speed compensation coefficient to obtain the corrected torque corresponding to the current moment, and a feedforward control instruction corresponding to the current moment is generated based on the corrected torque. The torque corresponding to the target steering wheel angle can be accurately determined based on the angle-torque mapping relationship, and the torque is corrected in combination with the vehicle speed to obtain an accurate corrected torque, thereby improving the accuracy of the feedforward control instruction determined based on the corrected torque, so that accurate steering wheel torque control instructions can be generated in combination with the feedforward instruction and the feedback instruction, thereby improving the control accuracy of the steering wheel torque.

[0085] In some embodiments, obtaining a preset angle-torque mapping relationship includes: determining a steering wheel torque control instruction corresponding to a sample steering wheel angle based on sample PID parameters; determining an actual angle corresponding to the sample steering wheel angle based on the steering wheel torque control instruction corresponding to the sample steering wheel angle; adjusting the sample PID parameters based on a deviation between the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle, and returning to execute the step of determining the steering wheel torque control instruction corresponding to the sample steering wheel angle until the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match; when the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match, determining the angle-torque mapping relationship based on the sample steering wheel angle and the steering wheel torque control instruction corresponding to the sample steering wheel angle.

[0086] The sample PID parameters may refer to PID parameters used as samples in the process of determining the angle-torque mapping relationship.

[0087] The sample steering wheel angle may refer to a steering wheel angle used as a sample in the process of determining the angle-torque mapping relationship. In practical applications, the sample steering wheel angle may be used as a target steering wheel angle corresponding to the sample.

[0088] As an example, the preset angle-torque mapping relationship can be obtained through pre-calibration. The pre-calibration process involves calibration samples. The calibration samples can characterize the steering wheel torque of the vehicle at a preset vehicle speed controlled based on the sample steering wheel angle. The on-board controller can determine the torque value corresponding to the sample steering wheel angle based on the preset sample PID parameters, and generate a steering wheel torque control instruction corresponding to the sample steering wheel angle based on the torque value corresponding to the sample steering wheel angle. The steering wheel torque control instruction corresponding to the sample steering wheel angle can be used for pure feedback control of the steering wheel torque. The on-board controller can send the steering wheel torque control instruction corresponding to the sample steering wheel angle to the vehicle steering mechanism. After the vehicle steering mechanism executes the steering wheel torque control instruction corresponding to the sample steering wheel angle, the on-board controller can obtain the actual angle corresponding to the sample steering wheel angle at this time, and then the on-board controller can calculate the deviation between the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle. When the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match (such as the deviation between the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle is less than or equal to a preset deviation threshold), the on-board controller can determine the angle-torque mapping relationship based on the sample steering wheel angle and the torque value corresponding to the steering wheel torque control instruction corresponding to the sample steering wheel angle. When the sample steering wheel angle and the actual steering angle corresponding to the sample steering wheel angle do not match (such as the deviation between the sample steering wheel angle and the actual steering angle corresponding to the sample steering wheel angle is greater than a preset deviation threshold), the on-board controller can adjust the sample PID parameters according to the deviation between the sample steering wheel angle and the actual steering angle corresponding to the sample steering wheel angle to obtain adjusted sample PID parameters, and then the on-board controller can determine a new steering wheel torque control instruction corresponding to the sample steering wheel angle according to the adjusted sample PID parameters, and determine a new steering wheel torque control instruction corresponding to the sample steering wheel angle according to the new steering wheel torque control instruction corresponding to the sample steering wheel angle The actual steering angle is calculated, and then the deviation between the sample steering wheel angle and the new actual steering angle corresponding to the sample steering wheel angle is calculated, and it is determined whether the sample steering wheel angle and the new actual steering angle corresponding to the sample steering wheel angle match. If the sample steering wheel angle and the new actual steering angle corresponding to the sample steering wheel angle do not match, the on-board controller can adjust the sample PID parameters again and repeat the above steps until the sample steering wheel angle and the new actual steering angle corresponding to the sample steering wheel angle match. At this time, the on-board controller can determine the steering angle torque mapping relationship according to the torque value corresponding to the sample steering wheel angle and the new steering wheel torque control command corresponding to the sample steering wheel angle. In practical applications, the sample steering wheel angle can be obtained based on a preset low-frequency sine curve θsine.

[0089] In this embodiment, the steering wheel torque control instruction corresponding to the sample steering wheel angle is determined according to the sample PID parameters; the actual angle corresponding to the sample steering wheel angle is determined according to the steering wheel torque control instruction corresponding to the sample steering wheel angle; the sample PID parameters are adjusted according to the deviation between the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle, and the step of determining the steering wheel torque control instruction corresponding to the sample steering wheel angle is returned to execute until the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match; when the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match, the angle-torque mapping relationship is determined according to the sample steering wheel angle and the steering wheel torque control instruction corresponding to the sample steering wheel angle, so that the correspondence between the steering wheel angle and the torque can be accurately analyzed based on the sample to obtain an accurate angle-torque mapping relationship.

[0090] In some embodiments, the vehicle speed compensation coefficient is obtained based on a preset vehicle speed coefficient mapping relationship and the vehicle speed; the vehicle speed coefficient mapping relationship is used to characterize the correspondence between the vehicle speed and the vehicle speed compensation coefficient; before obtaining the vehicle speed compensation coefficient at the current moment according to the vehicle speed, the above method also includes: obtaining the angle-torque mapping relationship; according to the sample steering wheel angles at different vehicle speeds and the angle-torque mapping relationship, obtaining the reference torque corresponding to the sample steering wheel angles at different vehicle speeds; determining the vehicle speed coefficient mapping relationship according to the reference torque corresponding to the sample steering wheel angles at different vehicle speeds and different vehicle speeds.

[0091] The vehicle speed coefficient mapping relationship may refer to information used to characterize the corresponding relationship between the vehicle speed and the vehicle speed compensation coefficient.

[0092] As an example, the correspondence between the vehicle speed and the vehicle speed compensation coefficient can be determined by the vehicle speed coefficient mapping relationship. Therefore, in the process of obtaining the vehicle speed compensation coefficient at the current moment according to the vehicle speed, the vehicle controller can first obtain the preset vehicle speed coefficient mapping relationship, and then find the vehicle speed compensation coefficient corresponding to the vehicle speed according to the vehicle speed coefficient mapping relationship as the vehicle speed compensation coefficient at the current moment. The vehicle speed coefficient mapping relationship can be obtained by pre-calibration. The vehicle controller can first determine the angle torque mapping relationship based on the calibration sample, and then determine the reference torque corresponding to the steering wheel torque control instruction corresponding to the sample steering wheel angle at different vehicle speeds in combination with the sample steering wheel angle at different vehicle speeds and the angle torque mapping relationship. After that, the vehicle controller can determine the vehicle speed coefficient mapping relationship according to the sample steering wheel angle, the reference torque corresponding to the steering wheel torque control instruction corresponding to the sample steering wheel angle at different vehicle speeds, and different vehicle speeds.

[0093] In this embodiment, the angle-torque mapping relationship is obtained; based on the sample steering wheel angles at different vehicle speeds and the angle-torque mapping relationship, the reference torque corresponding to the sample steering wheel angles at different vehicle speeds is obtained; based on the reference torque corresponding to the sample steering wheel angles at different vehicle speeds and different vehicle speeds, the vehicle speed coefficient mapping relationship is determined, and an accurate vehicle speed coefficient mapping relationship can be determined based on samples of different vehicle speeds, and an accurate vehicle speed compensation coefficient can be obtained using the vehicle speed coefficient mapping relationship.

[0094] In some embodiments, the PID parameter associated at the current moment is determined based on the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, including: obtaining a quantization mapping result of the angle deviation corresponding to the deviation in a preset quantization domain; the preset quantization domain includes multiple fuzzy parameters; based on the quantization mapping result of the angle deviation and preset fuzzy rules, determining the quantization mapping result of the PID parameter deviation in the preset quantization domain; the fuzzy rules are used to characterize the correspondence between the first fuzzy parameter corresponding to each angle deviation and the second fuzzy parameter corresponding to the PID parameter deviation; determining the parameter adjustment amount based on the product between the quantization mapping result of the PID parameter deviation and the preset maximum value of the PID parameter change; determining the PID parameter based on the preset nominal PID parameter and the parameter adjustment amount.

[0095] Among them, the preset quantization domain may refer to the numerical range in which the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle is quantized. In actual applications, the preset quantization domain may include a numerical set within {-3, 3}: {-3, -2, -1, 0, 1, 2, 3}. The preset quantization domain contains multiple fuzzy parameters. The fuzzy parameter of the angle deviation quantization mapping result in the preset quantization domain can be used as the first fuzzy parameter. The fuzzy parameter of the PID parameter deviation quantization mapping result in the preset quantization domain can be used as the second fuzzy parameter. The set of fuzzy parameters can be expressed as {NB, NM, NS, ZO, PS, PM, PB}.

[0096] The steering angle deviation quantization mapping result may refer to information obtained after the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle is mapped to a preset quantization domain.

[0097] The preset fuzzy rule may refer to information used to characterize the correspondence between a first fuzzy parameter corresponding to each steering angle deviation and a second fuzzy parameter corresponding to the PID parameter deviation.

[0098] The PID parameter deviation quantization mapping result may refer to information obtained after the adjustment amount of the PID parameter determined based on the first fuzzy parameter corresponding to the steering angle deviation and the second fuzzy parameter corresponding to the PID parameter deviation is mapped to a preset quantization domain.

[0099] Among them, the preset maximum value of PID parameter change can be expressed as ΔK pmax , ΔK imax , ΔK dmax .

[0100] The parameter adjustment amount may refer to information characterizing the degree of change of the PID parameters when the PID parameters of the PID controller are adjusted based on the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle.

[0101] Among them, the preset nominal PID parameters can be expressed as K p0 , ΔK i0 , ΔK d0 .

[0102] As an example, the on-board controller can first map the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle to a preset quantization domain, and obtain the angle deviation quantization mapping result corresponding to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle in the preset quantization domain. Then, the on-board controller can determine the first fuzzy parameter corresponding to the angle deviation quantization mapping result corresponding to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, the second fuzzy parameter corresponding to the PID parameter deviation, and the corresponding relationship between the first fuzzy parameter and the second fuzzy parameter according to the preset fuzzy rule. Then, the on-board controller can combine the second fuzzy parameter and the angle deviation quantization mapping result to determine the PID parameter deviation quantization mapping result in the preset quantization domain. Then, the on-board controller can determine the parameter adjustment amount according to the product between the PID parameter deviation quantization mapping result and the preset maximum value of the PID parameter change, and determine the PID parameter according to the sum between the preset nominal PID parameter and the parameter adjustment amount.

[0103] In this embodiment, by obtaining the quantization mapping result of the angle deviation corresponding to the deviation in the preset quantization domain; the preset quantization domain includes multiple fuzzy parameters; according to the quantization mapping result of the angle deviation and the preset fuzzy rule, the quantization mapping result of the PID parameter deviation in the preset quantization domain is determined; the fuzzy rule is used to characterize the correspondence between the first fuzzy parameter corresponding to each angle deviation and the second fuzzy parameter corresponding to the PID parameter deviation; the parameter adjustment amount is determined according to the product between the quantization mapping result of the PID parameter deviation and the preset maximum value of the PID parameter change; the PID parameters are determined according to the preset nominal PID parameters and the parameter adjustment amount, so that the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle can be mapped to the quantization domain, and the accurate PID parameter adjustment amount is determined in combination with the mapping result and the preset fuzzy rule, and then the accurate PID parameters are determined, so as to determine the accurate feedback control instructions based on the PID parameters.

[0104] In some embodiments, based on the angle deviation quantization mapping result and preset fuzzy rules, the PID parameter deviation quantization mapping result in the preset quantization domain is determined, including: based on the angle deviation quantization mapping result, determining the angle deviation membership information corresponding to each first fuzzy parameter; based on each angle deviation membership information and the preset fuzzy rules, obtaining the PID parameter deviation quantization mapping result.

[0105] The angle deviation membership information may refer to information calculated based on the angle deviation quantization mapping result and the membership function of each first fuzzy parameter corresponding to the angle deviation quantization mapping result. In practical applications, the angle deviation quantization mapping result may be expressed as e quantion , the membership function of the first fuzzy parameter can be expressed as μ(x), and the membership information of the angle deviation can be expressed as μ(e quantion ).

[0106] As an example, the quantization mapping result of the angle deviation may correspond to at least one fuzzy parameter, and the fuzzy parameter corresponding to the quantization mapping result of the angle deviation is recorded as a first fuzzy parameter, each first fuzzy parameter has a corresponding membership function, and the vehicle controller may calculate the angle deviation membership information corresponding to each first fuzzy parameter based on the quantization mapping result of the angle deviation and the membership function of each first fuzzy parameter corresponding to the quantization mapping result of the angle deviation, and then the vehicle controller may determine each second fuzzy parameter corresponding to the PID parameter deviation based on the preset fuzzy rule and each first fuzzy parameter corresponding to the quantization mapping result of the angle deviation, and calculate the PID parameter deviation quantization mapping result according to each first fuzzy parameter corresponding to the quantization mapping result of the angle deviation, each second fuzzy parameter corresponding to the PID parameter deviation, and the angle deviation membership information of each first fuzzy parameter. In actual applications, the vehicle controller may calculate the sum of the angle deviation membership information of each first fuzzy parameter as the denominator, and calculate the sum of the products of the angle deviation membership information of each first fuzzy parameter and the second fuzzy parameter corresponding to each first fuzzy parameter as the numerator, and then determine the PID parameter deviation quantization mapping result based on the ratio of the numerator to the denominator. In a specific implementation, each second fuzzy parameter corresponding to the PID parameter deviation can be expressed as K p _rule_matrix(x), the PID parameter deviation quantization mapping result can be expressed as ΔK p quantion , ΔK i quantion , ΔK d quantion .

[0107] In this embodiment, the angle deviation membership information corresponding to each first fuzzy parameter is determined according to the angle deviation quantization mapping result; the PID parameter deviation quantization mapping result is obtained according to each angle deviation membership information and preset fuzzy rules. Based on the angle deviation membership information corresponding to each first fuzzy parameter of the angle deviation quantization mapping result and the preset fuzzy rules, an accurate PID parameter deviation quantization mapping result can be determined.

[0108] In some embodiments, according to the quantization mapping result of the angle deviation, the membership information of the angle deviation corresponding to each first fuzzy parameter is determined, including: obtaining the membership function corresponding to each first fuzzy parameter; according to the quantization mapping result of the angle deviation and the membership function of each first fuzzy parameter, obtaining the membership information of the angle deviation corresponding to each first fuzzy parameter; according to each angle deviation membership information and preset fuzzy rules, obtaining the quantization mapping result of the PID parameter deviation, including: according to the preset fuzzy rules, obtaining the second fuzzy parameter corresponding to each first fuzzy parameter; according to the angle deviation membership information corresponding to each first fuzzy parameter and the second fuzzy parameter corresponding to each first fuzzy parameter, obtaining the quantization mapping result of the PID parameter deviation.

[0109] As an example, the vehicle-mounted controller can obtain the membership function corresponding to each first fuzzy parameter, and then calculate the steering angle deviation membership information corresponding to each first fuzzy parameter based on the steering angle deviation quantization mapping result and the membership function of each first fuzzy parameter. After that, the vehicle-mounted controller can determine the second fuzzy parameter corresponding to each first fuzzy parameter of the steering angle deviation quantization mapping result according to the preset fuzzy rules, and calculate the PID parameter deviation quantization mapping result based on the steering angle deviation membership information corresponding to each first fuzzy parameter and the second fuzzy parameter corresponding to each first fuzzy parameter.

[0110] In this embodiment, by obtaining the membership function corresponding to each first fuzzy parameter; obtaining the angle deviation membership information corresponding to each first fuzzy parameter according to the angle deviation quantization mapping result and the membership function of each first fuzzy parameter; obtaining the PID parameter deviation quantization mapping result according to each angle deviation membership information and preset fuzzy rules, including: obtaining the second fuzzy parameter corresponding to each first fuzzy parameter according to the preset fuzzy rule; obtaining the PID parameter deviation quantization mapping result according to the angle deviation membership information corresponding to each first fuzzy parameter and the second fuzzy parameter corresponding to each first fuzzy parameter, the angle deviation membership information can be accurately calculated based on the membership function, and the accurate PID parameter deviation quantization mapping result can be obtained in combination with the second fuzzy parameter corresponding to each first fuzzy parameter determined by the preset fuzzy rule and the angle deviation membership information corresponding to each first fuzzy parameter.

[0111] In some embodiments, Figure 2 As shown, a schematic diagram of a steering wheel torque control method based on a fuzzy PID algorithm is provided. The on-board controller can adopt a "torque feedforward + fuzzy PID feedback" structure to realize steering wheel angle to torque control. In the torque feedforward process, a pure feedback control algorithm is used to track the sinusoidal angle curve, obtain the torque command curve under the stable tracking state, and use it as the feedforward command. In the fuzzy PID feedback process, fuzzy PID is used according to the input error to generate feedback control commands. The input of the on-board controller includes the upper-level lateral control steering wheel angle command request, and the output of the on-board controller includes the steering wheel torque. The control logic of the steering wheel torque control based on the fuzzy PID algorithm can be expressed as: T cmd = T feedforward + T feedback , where T cmd Can be a torque command, T feedforward Can be a feedforward instruction, T feedback Can be a feedback command, and the feedforward command is the target steering wheel angle θ t The feedforward (torque) command can be expressed as T feedforward =f(θt ), the feedback command is about the target steering wheel angle θ t The fuzzy PID mapping of the deviation between the current steering wheel angle θ (such as the actual steering angle θ) and the feedback command can be expressed as T feedback = fuzzyPID(e), where e=θ t -θ.

[0112] Due to the nonlinear characteristics of steering wheel steering, the torque required to maintain balance at different steering wheel angles is different. Therefore, it is necessary to calibrate the corresponding torque value according to different steering wheel angles. The correlation between the torque value and the steering wheel angle can be expressed as: T θ = f(θ), where θ is the steering wheel angle, T θ is the torque value corresponding to the steering wheel angle θ. At the same time, under the same steering wheel angle, the steering wheel angle value under different vehicle speeds is also different. Therefore, considering the torque value under the steering wheel angle θ and vehicle speed v at the same time, the correlation between the torque value and the steering wheel angle can be expressed as: T θv = f(θ, v). After actual tests, it was found that the torque difference is not very large under different vehicle speed conditions. Therefore, assuming that the torque is proportional under the same angle and different vehicle speed conditions, the torque calibration process can be further simplified as: T θv = f(θ, v) ≈ K v T0=K v f(θ), where K v is the speed compensation coefficient / speed compensation coefficient, which can be calibrated according to different vehicle speeds. T0= f0 (θ) can represent the mapping of different steering wheel angles to torque under static vehicle conditions. At this time, the calibration problem is simplified to completing the parameter calibration of the curve T0= f0 (θ) under static conditions, and then adjusting K according to different speeds on this basis. v The torque feedforward command compensation method may include but is not limited to measurement method, modeling method and feedback control method.

[0113] Take the feedback control method to realize the compensation of torque feedforward command as an example: the vehicle controller can only rely on the calibration method of sending the torque command interface, such as Figure 3 As shown in the figure, a schematic diagram of torque command calibration is provided. The traditional PID control algorithm is used to track the very slowly changing angle sinusoidal curve. When the tracking process converges, the torque at this time is considered to be the quasi-balanced torque under the angle request, and it is used as the feedforward torque. At this time, T0= f0(θ)=PID(e)=PID(θ sine -θ), where θ sineThe input can be a standard slowly changing sinusoidal signal, which changes slowly enough for feedback control to effectively track and stabilize convergence. The general expression of PID at the kth moment is: PID (e k )=K p +K i ∑e k T s +K d [(e k -e k-1 ) / T s ], where T s is the sampling time, K p , K i and K d is the PID parameter. The calibration process can be simplified to the formula T θv =K v f0(θ) is calibrated. At this time, the on-board controller can determine that the feedforward command can be expressed as: T feedforward = T θv =K v f0(θ), in practical applications, such as Figure 4 As shown in FIG. 1 , a schematic diagram of the calibration process is provided. The vehicle controller can first construct a low-frequency sinusoidal curve θsine, then construct a pure feedback control and debug the PID parameters, thereby calibrating T0 = f0 (θ) until the system converges. At this time, the vehicle controller can determine that the angle and torque calibration are completed. Then, the vehicle controller can calibrate the speed based on the sinusoidal signals corresponding to different speeds, and fine-tune K according to different speeds. v , to achieve the expansion of different speeds, and finally get T θv =K v f0(θ).

[0114] Due to the nonlinear characteristics of the steering wheel, it is relatively difficult to achieve a stable and consistent convergence effect under different target steering wheel angle conditions even if the same set of PID parameters is used when the vehicle is stationary. At this time, fuzzy PID control can be used to set corresponding fuzzy rules according to different states, thereby obtaining different PID parameters, and finally obtaining targeted control instructions for different target states to achieve stable control. Figure 5 As shown in the figure, a schematic diagram of torque control based on fuzzy PID is provided. In fuzzy PID control, the fuzzy controller obtains the error as the input, and then it is calculated by the fuzzy controller and finally mapped to K p , K i , K dAfter the fuzzy controller outputs the PID parameters, it can generate torque instructions through the PID algorithm to control the vehicle steering mechanism. The fuzzy controller operation process can include parameter fuzzification, fuzzy reasoning, parameter defuzzification, and controller composition.

[0115] Parameter fuzzification can convert precise input values ​​into fuzzy sets, which usually involves dividing the range of input values ​​into several fuzzy subsets and defining membership functions for each subset. In practical applications, the vehicle controller can first define a fuzzy parameter set, such as {NB, NM, NS, ZO, PS, PM, PB}, and the values ​​of the fuzzy parameter set correspond to the numerical set in the quantization domain {-3, 3}, such as {-3, -2, -1, 0, 1, 2, 3}. Then the vehicle controller can calculate the maximum error value based on the preset error value e. max and the preset minimum error value -e max , the error e (such as the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle) is mapped to the quantized domain. The mapping formula can be expressed as: quantion =3e / e max , at this time it is easy to know that -3≤e quantion ≤3. The membership function corresponding to each subset may include but is not limited to triangular membership. Taking triangular membership as an example, the NB membership function can be expressed as follows: Figure 6 The content shown is provided by Figure 6 It can be seen that for the variables in the quantitative domain, there are: e quantion =-3, then it belongs to μ NB (e quantion ) = 1; e quantion ≥-2, then it belongs to μ NB (e quantion ) = 0; -3 ≤ e quantion ≤-2, then it belongs to μ NB (e quantion ) changes linearly from 1 to 0; the NM membership function can be expressed as Figure 7 The content shown is provided by Figure 7 It can be seen that for the variables in the quantitative domain, there are: e quantion =-3, then it belongs to μ NM (e quantion ) = 0; e quantion ≥-1, then it belongs to μ NM (e quantion ) = 0; -3 ≤ e quantion ≤-1, then it belongs to μ NM (e quantion ) first changes from 0 to 1, then from 1 to 0, e quantion =-2, then it belongs to μ NM (equantion ) = 1, the membership functions and fuzzy variables corresponding to NS, ZO, PS, PM, and PB are similar to the above membership functions, such as Figure 8 As shown, a schematic diagram of a fuzzy parameter membership function set is provided.

[0116] like Fig. 9 As shown in the figure, a schematic diagram of solving feedback control is provided. In the process of fuzzy reasoning, the on-board controller can respectively calculate K for the single input error e. p , K i , K d For fuzzy mapping, the mapping rules (fuzzy rules) can be pre-set. For example: p When the error is large, a larger K p , when the error is small, use a smaller K p , when the error is close to 0, take the minimum, then set K according to the above principle P Fuzzy rule K p _rule_matrix(i) can be expressed as shown in Table 1 below:

[0117] Table 1

[0118]

[0119] For K i When the error is large, use a smaller K i , to reduce K i Impact on response speed: when the error is close to 0, increase K i , in order to improve the steady-state convergence accuracy, the K set according to the above principle i Fuzzy rule K i _rule_matrix(i) can be expressed as shown in Table 2 below:

[0120] Table 2

[0121]

[0122] For K d When the error is large, a larger K d To speed up the response, when the error is close to 0, reduce K d In order to reduce the unnecessary large differential response caused by steady-state noise, the K set according to the above principle is d Fuzzy rule K d _rule_matrix(i) can be expressed as shown in Table 3 below:

[0123] Table 3

[0124]

[0125] In the process of fuzzy reasoning, the on-board controller can use the central average method to defuzzify and thus realize fuzzy mapping. For example, assuming that i is a fuzzy variable in the fuzzy parameter set {NB, NM, NS, ZO, PS, PM, PB}, then there is a quantization error e quantion To quantify the PID deviation parameter ΔK p , ΔK i , ΔK d The mapping relationship can be expressed as:

[0126] ,

[0127] ,

[0128] .

[0129] The steps of implementing parameter defuzzification of the on-board controller include: mapping the quantized PID deviation parameter to the PID change, assuming that the maximum change of the PID parameter is ΔK pmax , ΔK imax , ΔK dmax , then: -ΔK pmax ≤ΔK p ≤ΔK pmax , -ΔK imax ≤ΔK i ≤ΔK imax , -ΔK dmax ≤ΔK d ≤ΔK dmax At the same time, the relationship between the PID change and the quantization parameter is:

[0130] .

[0131] The vehicle controller can then use the preset nominal PID parameter K p0 , K i0 , K d0 Determine the final fuzzy PID parameters. In practical applications, the fuzzy PID parameters K p-fuzzy , K i-fuzzy , K d-fuzzy It can be expressed as:

[0132] .

[0133] The final fuzzy PID parameters change accordingly with the input error within the range of variation according to the fuzzy rules. The vehicle controller can determine the PID algorithm controller based on the fuzzy PID parameters, and then use the PID algorithm controller to determine the feedback command. At this time, the feedback command can be expressed as: Tfeedback =fuzzyPID(e). In practical applications, the fuzzy PID control at time k can be expressed as: fuzzyPID(e k ) = K p-fuzzy e k +K i-fuzzy ∑e k T s +K d-fuzzy [(e k -e k-1 ) / T s ], where T s Can be the sampling time.

[0134] In this embodiment, based on the feedforward torque method, a pure feedback control algorithm is adopted to track the sinusoidal angle curve, obtain the torque command curve under the stable tracking state, and use it as the feedforward command, and according to the input error, a fuzzy PID is adopted to generate a feedback control command, which can get rid of the dependence on external sensors in the process of generating the torque feedforward command, and only need to use the steering wheel torque control interface on the vehicle chassis, saving costs. In the process of generating the torque feedforward command, the dependence on the EPS internal power assist model is avoided, and the communication cost with the supplier is saved. The torque feedforward command is adopted, and the gain coefficient at different speeds is used for fine-tuning, so as to avoid the steering wheel torque calibration process from being dependent on dynamic speed changes, and then static calibration can be performed, avoiding dependence on the test site, saving costs, and using a fuzzy PID controller based on the torque feedback command to control The controller PID parameters are dynamically adjusted according to fuzzy rules as the control angle error changes. It is adaptable to nonlinear processes with different control characteristics under different steering wheel angles. The method of feedforward command + fuzzy PID feedback control is independent of the control model, which can avoid the system identification process of complex model parameters and save costs. The feedforward command + feedback command method is adopted, so that the feedforward command is used for large deviation response, and the feedback command is used to solve small control deviation, thereby achieving the coordination and unification of response speed and control accuracy, and finally forming a high-dynamic and high-precision steering wheel angle response system, avoiding the response hysteresis and insufficient accuracy of general feedback control methods, and avoiding modeling of the control object, thereby avoiding the modeling difficulties caused by nonlinearity and the parameter calibration difficulties caused by the modeling method, thereby achieving precise control of the steering wheel torque.

[0135] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0136] Based on the same inventive concept, the embodiment of the present application also provides a steering wheel torque control device for implementing the above-mentioned steering wheel torque control method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more steering wheel torque control device embodiments provided below can refer to the above-mentioned limitations on the steering wheel torque control method, and will not be repeated here.

[0137] In an exemplary embodiment, Fig.10 As shown, a steering wheel torque control device is provided, comprising: a steering angle acquisition module 1002, a feedforward determination module 1004, a feedback determination module 1006 and a torque control module 1008, wherein:

[0138] The steering angle acquisition module 1002 is used to acquire the target steering wheel angle carried in the steering wheel angle request instruction of the target vehicle corresponding to the current moment.

[0139] The feedforward determination module 1004 is used to obtain the feedforward control instruction corresponding to the current moment according to the target steering wheel angle.

[0140] The feedback determination module 1006 is used to determine the PID parameters associated with the current moment according to the deviation between the actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle, and to determine the feedback control instructions corresponding to the current moment according to the PID parameters and the deviation.

[0141] The torque control module 1008 is used to generate a steering wheel torque control instruction for the current moment based on the feedforward control instruction and the feedback control instruction; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle.

[0142] In one of the exemplary embodiments, the feedforward determination module 1004 is specifically used to obtain a preset angle-torque mapping relationship; the angle-torque mapping relationship is used to characterize the correspondence between the steering wheel angle and the steering wheel torque; according to the target steering wheel angle and the angle-torque mapping relationship, the reference torque corresponding to the current moment is obtained; the speed of the target vehicle at the current moment is obtained, and the speed compensation coefficient at the current moment is obtained according to the speed; the reference torque is corrected using the speed compensation coefficient to obtain the corrected torque corresponding to the current moment, and the feedforward control instruction corresponding to the current moment is generated based on the corrected torque.

[0143] In one of the exemplary embodiments, the feedforward determination module 1004 is specifically used to determine the steering wheel torque control instruction corresponding to the sample steering wheel angle according to the sample PID parameters; determine the actual angle corresponding to the sample steering wheel angle according to the steering wheel torque control instruction corresponding to the sample steering wheel angle; adjust the sample PID parameters according to the deviation between the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle, and return to execute the step of determining the steering wheel torque control instruction corresponding to the sample steering wheel angle until the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match; when the sample steering wheel angle and the actual angle corresponding to the sample steering wheel angle match, determine the angle-torque mapping relationship according to the sample steering wheel angle and the steering wheel torque control instruction corresponding to the sample steering wheel angle.

[0144] In one of the exemplary embodiments, the vehicle speed compensation coefficient is obtained based on a preset vehicle speed coefficient mapping relationship and the vehicle speed; the vehicle speed coefficient mapping relationship is used to characterize the correspondence between the vehicle speed and the vehicle speed compensation coefficient; the feedforward determination module 1004 is also specifically used to obtain the steering angle torque mapping relationship; according to the sample steering wheel angles at different vehicle speeds and the steering angle torque mapping relationship, the reference torque corresponding to the sample steering wheel angles at different vehicle speeds is obtained; according to the reference torque corresponding to the sample steering wheel angles at different vehicle speeds and the different vehicle speeds, the vehicle speed coefficient mapping relationship is determined.

[0145] In one of the exemplary embodiments, the feedback determination module 1006 is specifically used to obtain a quantization mapping result of a steering angle deviation corresponding to the deviation in a preset quantization domain; the preset quantization domain includes multiple fuzzy parameters; according to the quantization mapping result of the steering angle deviation and a preset fuzzy rule, a quantization mapping result of a PID parameter deviation in the preset quantization domain is determined; the fuzzy rule is used to characterize the correspondence between a first fuzzy parameter corresponding to each steering angle deviation and a second fuzzy parameter corresponding to the PID parameter deviation; a parameter adjustment amount is determined according to the product between the quantization mapping result of the PID parameter deviation and a preset maximum value of the PID parameter change; and the PID parameter is determined according to a preset nominal PID parameter and the parameter adjustment amount.

[0146] In one of the exemplary embodiments, the feedback determination module 1006 is specifically used to determine the steering angle deviation membership information corresponding to each of the first fuzzy parameters based on the steering angle deviation quantization mapping result; and obtain the PID parameter deviation quantization mapping result based on each of the steering angle deviation membership information and the preset fuzzy rules.

[0147] In one of the exemplary embodiments, the feedback determination module 1006 is specifically used to obtain the membership function corresponding to each of the first fuzzy parameters; obtain the angle deviation membership information corresponding to each of the first fuzzy parameters according to the angle deviation quantization mapping result and the membership function of each of the first fuzzy parameters; obtain the second fuzzy parameter corresponding to each of the first fuzzy parameters according to the preset fuzzy rules; obtain the PID parameter deviation quantization mapping result according to the angle deviation membership information corresponding to each of the first fuzzy parameters and the second fuzzy parameter corresponding to each of the first fuzzy parameters.

[0148] Each module in the above-mentioned steering wheel torque control device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each module.

[0149] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in FIG. Fig.11As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a steering wheel torque control method is implemented. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0150] Those skilled in the art will understand that Fig.11 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0151] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0152] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0153] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0154] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0155] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0156] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0157] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A steering wheel torque control method, characterized in that: The method comprises: Obtaining a target steering wheel angle carried in a steering wheel angle request instruction corresponding to the current moment of the target vehicle; Obtaining a feedforward control instruction corresponding to the current moment according to the target steering wheel angle; Obtaining a quantization mapping result of an angle deviation corresponding to a deviation between an actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle in a preset quantization domain, determining a quantization mapping result of a PID parameter deviation in the preset quantization domain according to the quantization mapping result of the angle deviation and a preset fuzzy rule, determining a PID parameter associated with the current moment according to the PID parameter deviation quantization mapping result and a preset nominal PID parameter, and determining a feedback control instruction corresponding to the current moment according to the PID parameter and the deviation; the preset quantization domain includes a plurality of fuzzy parameters; the fuzzy rule is used to characterize a correspondence between a first fuzzy parameter corresponding to each angle deviation and a second fuzzy parameter corresponding to the PID parameter deviation; Based on the feedforward control instruction and the feedback control instruction, a steering wheel torque control instruction for the current moment is generated; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle.

2. The method according to claim 1, characterized in that The step of obtaining the feedforward control instruction corresponding to the current moment according to the target steering wheel angle includes: Obtaining a preset steering angle torque mapping relationship; the steering angle torque mapping relationship is used to characterize the corresponding relationship between the steering wheel angle and the steering wheel torque; Obtaining the reference torque corresponding to the current moment according to the target steering wheel angle and the angle-torque mapping relationship; Acquire the speed of the target vehicle at the current moment, and obtain a speed compensation coefficient at the current moment according to the speed; The reference torque is corrected by using the vehicle speed compensation coefficient to obtain a correction torque corresponding to the current moment, and a feedforward control command corresponding to the current moment is generated based on the correction torque.

3. The method according to claim 2, characterized in that The obtaining of a preset angle torque mapping relationship includes: Determine the steering wheel torque control command corresponding to the sample steering wheel angle according to the sample PID parameters; determining an actual steering angle corresponding to the sample steering wheel angle according to a steering wheel torque control instruction corresponding to the sample steering wheel angle; adjusting the sample PID parameter according to a deviation between the sample steering wheel angle and an actual angle corresponding to the sample steering wheel angle, and returning to the step of determining the steering wheel torque control instruction corresponding to the sample steering wheel angle until the sample steering wheel angle matches the actual angle corresponding to the sample steering wheel angle; In a case where the sample steering wheel angle and the actual steering angle corresponding to the sample steering wheel angle match, the angle-torque mapping relationship is determined according to the sample steering wheel angle and the steering wheel torque control instruction corresponding to the sample steering wheel angle.

4. The method according to claim 3, characterized in that The vehicle speed compensation coefficient is obtained based on a preset vehicle speed coefficient mapping relationship and the vehicle speed; the vehicle speed coefficient mapping relationship is used to characterize the corresponding relationship between the vehicle speed and the vehicle speed compensation coefficient; before obtaining the vehicle speed compensation coefficient at the current moment according to the vehicle speed, it also includes: Acquire the rotation angle torque mapping relationship; According to the sample steering wheel angles at different vehicle speeds and the angle-torque mapping relationship, a reference torque corresponding to the sample steering wheel angles at different vehicle speeds is obtained; The vehicle speed coefficient mapping relationship is determined according to the reference torque corresponding to the sample steering wheel angles at the different vehicle speeds and the different vehicle speeds.

5. The method according to claim 1, characterized in that The determining the PID parameter associated at the current moment according to the PID parameter deviation quantization mapping result and the preset nominal PID parameter includes: Determine the parameter adjustment amount according to the product between the PID parameter deviation quantization mapping result and the preset PID parameter change maximum value; The PID parameters are determined according to the preset nominal PID parameters and the parameter adjustment amount.

6. The method according to claim 1, characterized in that The step of determining the PID parameter deviation quantization mapping result in the preset quantization domain according to the steering angle deviation quantization mapping result and the preset fuzzy rule includes: Determining the degree of membership of the corner deviations corresponding to the first fuzzy parameters according to the corner deviation quantization mapping result; According to the membership information of each steering angle deviation and the preset fuzzy rule, the PID parameter deviation quantization mapping result is obtained.

7. The method according to claim 6, characterized in that The step of determining the angle deviation membership information corresponding to each of the first fuzzy parameters according to the angle deviation quantization mapping result includes: Obtaining a membership function corresponding to each of the first fuzzy parameters; Obtaining, according to the quantization mapping result of the turning angle deviation and the membership function of each of the first fuzzy parameters, the turning angle deviation membership information corresponding to each of the first fuzzy parameters; The step of obtaining the PID parameter deviation quantization mapping result according to the steering angle deviation membership information and the preset fuzzy rule includes: According to the preset fuzzy rule, obtaining the second fuzzy parameter corresponding to each of the first fuzzy parameters; The PID parameter deviation quantization mapping result is obtained according to the steering angle deviation membership information corresponding to each of the first fuzzy parameters and the second fuzzy parameters corresponding to each of the first fuzzy parameters.

8. A steering wheel torque control device, characterized in that: The device comprises: Angle acquisition module, used to acquire the target steering wheel angle carried in the steering wheel angle request instruction corresponding to the current moment of the target vehicle; A feedforward determination module, used to obtain a feedforward control instruction corresponding to the current moment according to the target steering wheel angle; A feedback determination module, used for obtaining a quantization mapping result of an angle deviation corresponding to a deviation between an actual steering wheel angle of the target vehicle at the current moment and the target steering wheel angle in a preset quantization domain, determining a quantization mapping result of a PID parameter deviation in the preset quantization domain according to the quantization mapping result of the angle deviation and a preset fuzzy rule, determining a PID parameter associated at the current moment according to the PID parameter deviation quantization mapping result and a preset nominal PID parameter, and determining a feedback control instruction corresponding to the current moment according to the PID parameter and the deviation; the preset quantization domain includes a plurality of fuzzy parameters; the fuzzy rule is used for characterizing a correspondence between a first fuzzy parameter corresponding to each angle deviation and a second fuzzy parameter corresponding to the PID parameter deviation; The torque control module is used to generate a steering wheel torque control instruction for the current moment based on the feedforward control instruction and the feedback control instruction; the steering wheel torque control instruction is used to instruct the target vehicle to control the steering wheel angle torque of the target vehicle.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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