Rear wheel steering control method, device, vehicle and storage medium

Abstract

This application relates to the field of vehicle technology and provides a rear-wheel steering control method, device, vehicle, and storage medium. The rear-wheel steering control method includes: when the rear-wheel steering function is activated, determining a feedforward rear-wheel steering rate that conforms to the vehicle's current rear-wheel steering mode based on the actual rear-wheel steering rate and a correction coefficient; the correction coefficient is a coefficient corresponding to the rear-wheel steering mode. Based on the vehicle's driving parameters and body parameters, determining a feedback rear-wheel steering rate that conforms to the vehicle's current state. Finally, based on the feedforward and feedback rear-wheel steering rates, a target rear-wheel steering rate is determined that conforms to both the current rear-wheel steering mode and the vehicle's current state. When the vehicle's rear wheels rotate at the target rear-wheel steering rate, the vehicle achieves stable steering.

Description

Technical Field

[0001] This application belongs to the field of vehicle technology, and in particular relates to a rear-wheel steering control method, device, vehicle, and storage medium. Background Technology

[0002] Currently, some vehicles are equipped with rear-wheel steering technology, which allows for more flexible steering. However, current rear-wheel steering systems only have one fixed steering mode. Regardless of the wheel's position, the rear wheels steer at a fixed angle rate. In some situations, this can cause abruptness and lag when the rear wheels are steering, affecting vehicle stability. Summary of the Invention

[0003] This application provides a rear-wheel steering control method, device, vehicle, and storage medium, which can solve the problem of vehicle stability being affected when the rear wheels are steering.

[0004] In a first aspect, embodiments of this application provide a rear-wheel steering control method, including:

[0005] When the rear wheel steering function is activated, the feedforward rear wheel steering rate is determined based on the actual rear wheel steering rate and the correction coefficient; the correction coefficient is the coefficient corresponding to the rear wheel steering mode.

[0006] Based on the vehicle's driving parameters and the vehicle's body parameters, determine the feedback rear wheel steering angle rate;

[0007] The target rear wheel angular rate is determined based on the feedforward rear wheel angular rate and the feedback rear wheel angular rate.

[0008] In one possible implementation of the first aspect, determining the feedforward rear wheel angular rate based on the actual rear wheel angular rate and the correction coefficient includes:

[0009] Obtain the vehicle's current rear-wheel steering mode;

[0010] The correction coefficient is determined based on the rear wheel steering pattern;

[0011] The actual rear wheel steering rate is corrected based on the correction coefficient to obtain the feedforward rear wheel steering rate.

[0012] In one possible implementation of the first aspect, the step of correcting the actual rear wheel steering rate based on the correction coefficient to obtain the feedforward rear wheel steering rate includes:

[0013] The feedforward rear wheel angular rate is obtained by multiplying the actual rear wheel angular rate by the correction coefficient.

[0014] In one possible implementation of the first aspect, the vehicle's driving parameters include vehicle speed, actual yaw rate, front wheel steering angle, and rear wheel steering angle, and the vehicle's body parameters include vehicle weight, front and rear wheelbase, front and rear axle stiffness, and rear wheel track.

[0015] Determining the feedback rear wheel steering rate based on the vehicle's driving parameters and body parameters includes:

[0016] The stability factor is determined based on the vehicle weight, the front and rear wheelbase, and the front and rear axle stiffness.

[0017] The desired yaw rate is determined based on the vehicle speed, the front wheel steering angle, the rear wheel steering angle, the rear wheel track, and the stability factor.

[0018] The feedback rear wheel rotation rate is determined based on the desired yaw rate and the actual yaw rate.

[0019] In one possible implementation of the first aspect, determining the feedback rear wheel steering rate based on the desired yaw rate and the actual yaw rate includes:

[0020] Calculate the difference between the desired yaw rate and the actual yaw rate to obtain the yaw rate difference;

[0021] The yaw rate difference is adjusted using PID control to obtain the feedback rear wheel rotation rate.

[0022] In one possible implementation of the first aspect, determining the target rear wheel steering rate based on the feedforward rear wheel steering rate and the feedback rear wheel steering rate includes:

[0023] The target rear wheel angular rate is obtained by calculating the sum of the feedforward rear wheel angular rate and the feedback rear wheel angular rate.

[0024] In one possible implementation of the first aspect, the rear-wheel steering control method further includes:

[0025] Upon receiving a rear-wheel steering mode request, determine whether the conditions for switching rear-wheel steering mode are met based on the vehicle's status parameters and driving parameters.

[0026] If it is determined that the conditions for switching the rear wheel steering mode are met, respond to the rear wheel steering mode request.

[0027] Secondly, embodiments of this application provide a rear-wheel steering control device, including:

[0028] The feedforward module is used to determine the feedforward rear wheel angular rate based on the actual rear wheel angular rate and the correction coefficient when the rear wheel steering function is enabled; the correction coefficient is the coefficient corresponding to the rear wheel steering mode.

[0029] The feedback module is used to determine the feedback rear wheel steering rate based on the vehicle's driving parameters and the vehicle's body parameters.

[0030] The target rear wheel steering rate determination module is used to determine the target rear wheel steering rate based on the feedforward rear wheel steering rate and the feedback rear wheel steering rate.

[0031] Thirdly, embodiments of this application provide a vehicle including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method as described in any one of the first aspects.

[0032] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method as described in any one of the first aspects.

[0033] Fifthly, embodiments of this application provide a computer program product that, when run on a vehicle, causes the vehicle to perform the method described in any one of the first aspects above.

[0034] The beneficial effects of the embodiments in this application compared with the prior art are:

[0035] When rear-wheel steering is engaged, the feedforward rear-wheel steering rate is determined based on the actual rear-wheel steering rate and a correction coefficient. The correction coefficient corresponds to the rear-wheel steering mode. Based on the actual rear-wheel steering rate and the correction coefficient, a feedforward rear-wheel steering rate suitable for the vehicle's current rear-wheel steering mode can be determined. Then, based on the vehicle's driving and body parameters, the feedback rear-wheel steering rate is determined. These parameters characterize the vehicle's current state, and a feedback rear-wheel steering rate suitable for the vehicle's current state can be determined. Finally, based on the feedforward and feedback rear-wheel steering rates, the target rear-wheel steering rate is determined. This target rear-wheel steering rate conforms to both the current rear-wheel steering mode and the vehicle's current state. When the rear wheels rotate at the target rear-wheel steering rate, the vehicle achieves stable steering.

[0036] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic flowchart of a rear wheel steering control method provided in an embodiment of this application;

[0039] Figure 2 This is a schematic flowchart of a rear-wheel steering control method provided in another embodiment of this application;

[0040] Figure 3 This is a schematic flowchart of a rear wheel steering control method provided in another embodiment of this application;

[0041] Figure 4 This is a schematic diagram of the structure of the rear wheel steering control device provided in the embodiments of this application;

[0042] Figure 5 This is a schematic diagram of the vehicle structure provided in the embodiments of this application. Detailed Implementation

[0043] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0044] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0045] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0046] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0047] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0048] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0049] Current vehicles offer multiple front-wheel steering modes, such as Light, Sport, and Comfort. Each mode corresponds to a different power steering torque to meet the driver's individual driving needs. For instance, in Light mode, the power steering motor provides a larger torque, and the driver contributes less torque when the front wheels turn the same angle. Conversely, in Comfort mode, the power steering motor provides a smaller torque, and the driver contributes more torque when the front wheels turn the same angle. Therefore, when the driver uses the same amount of force to turn the steering wheel, the steering wheel angle and the rate of front wheel rotation differ depending on the steering mode.

[0050] However, the rear-wheel steering of current vehicles is only set to one fixed steering mode. That is, regardless of the state of the wheels, the rear wheels will only turn at a fixed angle rate when turning. In some cases, the vehicle may experience abruptness and lag when turning the rear wheels, which will affect the stability of the vehicle.

[0051] Based on the above problems, this application provides a rear-wheel steering control method, such as... Figure 1 As shown, the rear wheel steering control method includes steps S101 to S103.

[0052] Step S101: When the rear wheel steering function is enabled, determine the feedforward rear wheel steering rate based on the actual rear wheel steering rate and the correction coefficient; the correction coefficient is the coefficient corresponding to the rear wheel steering mode.

[0053] Specifically, when the rear-wheel steering function is activated, the actual rear-wheel steering angle rate and correction coefficient are obtained. The actual rear-wheel steering angle rate can be obtained through sensors on the vehicle. The correction coefficient corresponds to the rear-wheel steering mode; therefore, before obtaining the correction coefficient, the vehicle's current rear-wheel steering mode needs to be identified. Once the rear-wheel steering mode is determined, the corresponding correction coefficient is determined based on that mode.

[0054] Designers can set multiple rear-wheel steering modes based on the actual conditions of the vehicle and assign corresponding correction coefficients to each mode. For example, the rear-wheel steering modes of the vehicle can be set to Light, Comfort, and Sport modes, with a correction coefficient of K corresponding to Light mode. 轻便 The correction factor for Comfort mode is K. 舒适 The correction factor corresponding to the motion mode is K. 运动 , where K 轻便 >K 舒适 >K 运动 Once the rear-wheel steering pattern of the vehicle is identified, the corresponding correction coefficient can be determined based on the rear-wheel steering pattern.

[0055] Once the actual rear wheel steering rate and correction coefficient are determined, the actual rear wheel steering rate is corrected based on the correction coefficient to obtain the feedforward rear wheel steering rate.

[0056] For example, the product of the actual rear wheel steering rate and the correction coefficient is calculated to obtain the feedforward rear wheel steering rate.

[0057] Since the correction factor is determined based on the rear wheel steering pattern, the actual rear wheel steering rate is corrected based on the correction factor, and the resulting feedforward rear wheel steering rate matches the vehicle's current rear wheel steering pattern.

[0058] Step S102: Determine the feedback rear wheel steering rate based on the vehicle's driving parameters and body parameters.

[0059] Specifically, the vehicle's driving parameters include vehicle speed, actual yaw rate, front wheel steering angle, and rear wheel steering angle. The vehicle's body parameters include vehicle weight, front and rear wheelbase, front and rear axle stiffness, and rear track width. Once the vehicle speed, actual yaw rate, front wheel steering angle, rear wheel steering angle, vehicle weight, front and rear wheelbase, front and rear axle stiffness, and rear track width are determined, the feedback rear wheel steering rate is calculated based on these parameters. Since the feedback rear wheel steering rate is determined based on the vehicle's driving parameters and body parameters, it reflects the vehicle's current state.

[0060] In some embodiments, such as Figure 2 As shown, step S102 may include steps S1021 to S1023.

[0061] Step S1021: Determine the stability factor based on the vehicle weight, front and rear wheelbase, and front and rear axle stiffness.

[0062] Specifically, vehicle weight can be obtained through sensors on the vehicle or pre-calibrated by the designers. The front and rear wheelbase, the distance between the center points of the front and rear axles, can also be pre-calibrated by the designers. Front and rear axle stiffness can be obtained by collecting data from sensors on the vehicle and processing the data, or it can be pre-calibrated by the designers. This application does not limit the methods for obtaining vehicle weight, front and rear wheelbase, and front and rear axle stiffness.

[0063] Once the vehicle weight, front and rear wheelbase, and front and rear axle stiffness are obtained, the stability factor is determined based on these parameters.

[0064] Step S1022: Determine the desired yaw rate based on vehicle speed, front wheel steering angle, rear wheel steering angle, rear wheel track, and stability factor.

[0065] Specifically, vehicle speed refers to the vehicle's current speed, which can be obtained through sensors on the vehicle. The front and rear wheel steering angles can also be obtained through sensors on the vehicle. The rear track width is the distance between the two rear wheels of the vehicle, which can be obtained through sensors on the vehicle or pre-calibrated by the designers. This application does not limit the methods for obtaining vehicle speed, front wheel steering angle, rear wheel steering angle, and rear track width.

[0066] Once the vehicle speed, front wheel steering angle, rear wheel steering angle, rear wheel track width, and stability factor are determined, the difference between the front and rear wheel steering angles is calculated to obtain the steering angle difference. The ratio of the vehicle speed to the rear wheel track width is then calculated to obtain the first ratio. Based on the vehicle speed and stability factor, the stability parameters are calculated. Finally, based on the steering angle difference, the first ratio, and the stability parameters, the desired yaw rate is obtained.

[0067] Step S1023: Determine the feedback rear wheel rotation rate based on the desired yaw rate and the actual yaw rate.

[0068] Specifically, the actual yaw rate can be obtained by sensors on the vehicle. Once the desired yaw rate and the actual yaw rate are determined, the feedback rear wheel rotation rate is determined based on the desired yaw rate and the actual yaw rate.

[0069] For example, firstly, the difference between the desired yaw rate and the actual yaw rate is calculated to obtain the yaw rate difference. Then, the yaw rate difference is input into a PID (Proportion-Integral-Differential) controller to adjust the yaw rate difference using PID control, thereby obtaining the feedback rear wheel rotation rate.

[0070] Step S103: Determine the target rear wheel angular rate based on the feedforward rear wheel angular rate and the feedback rear wheel angular rate.

[0071] Specifically, once the feedforward rear wheel angular rate and the feedback rear wheel angular rate are determined, the target rear wheel angular rate is determined based on these two rates.

[0072] For example, the target rear wheel angular rate is obtained by calculating the sum of the feedforward rear wheel angular rate and the feedback rear wheel angular rate.

[0073] Because the feedforward rear wheel angular rate matches the vehicle's current rear wheel steering pattern, and the feedback rear wheel angular rate matches the vehicle's current state, the target rear wheel angular rate determined based on the feedforward and feedback rear wheel angular rates matches both the vehicle's current rear wheel steering pattern and its current state. When the vehicle's rear wheels rotate at the target rear wheel angular rate, the vehicle can achieve stable steering.

[0074] In some embodiments, such as Figure 3 As shown, the rear wheel steering control method also includes steps S301 and S302.

[0075] Step S301: Upon receiving a rear-wheel steering mode request, determine whether the conditions for switching rear-wheel steering mode are met based on the vehicle's status parameters and driving parameters.

[0076] Specifically, during a turn, the driver may switch the rear-wheel steering mode. For example, the driver may activate the rear-wheel steering mode while the vehicle is turning. Or, the driver may switch the rear-wheel steering mode from one steering mode to another while the vehicle is turning.

[0077] When the driver needs to switch to rear-wheel steering mode, a rear-wheel steering mode request is sent. Upon receiving the request, the system determines whether the conditions for switching rear-wheel steering mode are met based on the vehicle's status and driving parameters.

[0078] Vehicle status parameters include rear wheel steering calibration status, rear wheel steering fault status, rear wheel steering switch status, rear wheel steering motor status, power supply status, steering mode request status, driver's steering wheel torque, and steering wheel angle rate. Vehicle driving parameters include vehicle speed.

[0079] The rear-wheel steering mode switching condition is determined to be met if all of the vehicle's state parameters and driving parameters meet the following conditions:

[0080] Condition 1: The rear wheel steering calibration status is calibrated.

[0081] Condition 2: The rear wheel steering fault status is "no fault".

[0082] Condition 3: The rear wheel steering switch is in the ON position.

[0083] Condition 4: The rear wheel steering motor is in normal condition.

[0084] Condition 5: The power status bit is KL150N.

[0085] Condition 6: Vehicle speed is less than 120 km / h (can be calibrated).

[0086] Condition 7: The driver's steering wheel torque is less than 2 Nm (calibrable) and lasts for 200 ms or more.

[0087] Condition 8: The steering wheel turning rate is less than 360 deg / s and lasts for 200 ms or more.

[0088] Condition 9: The steering mode request status is fault-free.

[0089] If the vehicle's status parameters and driving parameters do not meet any of the above conditions, then the rear wheel steering mode switching conditions are not met.

[0090] Step S302: If it is determined that the rear wheel steering mode switching conditions are met, respond to the rear wheel steering mode request.

[0091] Specifically, if the conditions for switching rear-wheel steering mode are met, the vehicle can switch to rear-wheel steering mode. In this case, the vehicle responds to the rear-wheel steering mode request and switches to the requested mode, thus achieving the rear-wheel steering mode switch. If the conditions for switching rear-wheel steering mode are not met, the vehicle is prevented from switching rear-wheel steering mode.

[0092] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0093] Figure 4 A schematic diagram of the rear wheel steering control device provided in an embodiment of this application is shown. See also... Figure 3 As shown, the rear wheel steering control device includes:

[0094] Feedforward module 41 is used to determine the feedforward rear wheel angular rate based on the actual rear wheel angular rate and the correction coefficient when the rear wheel steering function is activated; the correction coefficient is the coefficient corresponding to the rear wheel steering mode.

[0095] Feedback module 42 is used to determine the feedback rear wheel steering rate based on the vehicle's driving parameters and the vehicle's body parameters;

[0096] The target rear wheel steering rate determination module 43 is used to determine the target rear wheel steering rate based on the feedforward rear wheel steering rate and the feedback rear wheel steering rate.

[0097] In one embodiment of this application, the feedforward module 41 is further configured to:

[0098] Obtain the vehicle's current rear-wheel steering mode;

[0099] The correction coefficient is determined based on the rear wheel steering pattern;

[0100] The actual rear wheel steering rate is corrected based on the correction coefficient to obtain the feedforward rear wheel steering rate.

[0101] In one embodiment of this application, the feedforward module 41 is further configured to:

[0102] The feedforward rear wheel angular rate is obtained by multiplying the actual rear wheel angular rate by the correction coefficient.

[0103] In one embodiment of this application, the vehicle's driving parameters include vehicle speed, actual yaw rate, front wheel angle and rear wheel angle, and the vehicle's body parameters include vehicle weight, front and rear wheelbase, front and rear axle stiffness and rear wheel track.

[0104] Feedback module 42 is also used for:

[0105] The stability factor is determined based on the vehicle weight, the front and rear wheelbase, and the front and rear axle stiffness.

[0106] The desired yaw rate is determined based on the vehicle speed, the front wheel steering angle, the rear wheel steering angle, the rear wheel track, and the stability factor.

[0107] The feedback rear wheel rotation rate is determined based on the desired yaw rate and the actual yaw rate.

[0108] In one embodiment of this application, the feedback module 42 is further configured to:

[0109] Calculate the difference between the desired yaw rate and the actual yaw rate to obtain the yaw rate difference;

[0110] The yaw rate difference is adjusted using PID control to obtain the feedback rear wheel rotation rate.

[0111] In one embodiment of this application, the target rear wheel steering angle rate determination module 43 is further configured to:

[0112] The target rear wheel angular rate is obtained by calculating the sum of the feedforward rear wheel angular rate and the feedback rear wheel angular rate.

[0113] In one embodiment of this application, the rear wheel steering control device further includes:

[0114] The condition determination module is used to determine whether the conditions for switching the rear wheel steering mode are met based on the vehicle's status parameters and driving parameters when a rear wheel steering mode request is received.

[0115] The switching module is used to respond to the rear wheel steering mode request if it is determined that the rear wheel steering mode switching conditions are met.

[0116] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0117] Figure 5 This is a structural schematic diagram of a vehicle provided in an embodiment of this application. Figure 5 As shown, the vehicle 5 in this embodiment may include: at least one processor 50 ( Figure 5Only one processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the at least one processor 50 are shown. When the processor 50 executes the computer program 52, it implements the steps in any of the above method embodiments, for example... Figure 1 Steps S101 to S103 in the illustrated embodiment. Alternatively, when the processor 50 executes the computer program 52, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 4 The functions of modules 41 to 43 are shown.

[0118] For example, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to complete the present invention. The one or more modules / units may be a series of computer program 52 instruction segments capable of performing a specific function, which describe the execution process of the computer program 52 in the vehicle 5.

[0119] This application also provides a computer-readable storage medium storing a computer program 52, which, when executed by a processor 50, implements the steps described in the various method embodiments above.

[0120] This application provides a computer program product that, when run on a vehicle, enables the vehicle to perform the steps described in the various method embodiments above.

[0121] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program 52 instructing related hardware. The computer program 52 can be stored in a computer-readable storage medium, and when executed by the processor 50, it can implement the steps of the various method embodiments described above. The computer program 52 includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a terminal, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0122] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0123] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0124] In the embodiments provided in this application, it should be understood that the disclosed apparatus / network devices and methods can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0125] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A rear-wheel steering control method, characterized in that, include: When the rear wheel steering function is activated, the feedforward rear wheel steering rate is determined based on the actual rear wheel steering rate and the correction coefficient. The correction factor is the factor corresponding to the rear wheel steering mode; Based on the vehicle's driving parameters and the vehicle's body parameters, determine the feedback rear wheel steering angle rate; The target rear wheel angular rate is determined based on the feedforward rear wheel angular rate and the feedback rear wheel angular rate. The vehicle's driving parameters include vehicle speed, actual yaw rate, front wheel steering angle, and rear wheel steering angle; the vehicle's body parameters include vehicle weight, front and rear wheelbase, front and rear axle stiffness, and rear wheel track. Determining the feedback rear wheel steering rate based on the vehicle's driving parameters and body parameters includes: The stability factor is determined based on the vehicle weight, the front and rear wheelbase, and the front and rear axle stiffness. The desired yaw rate is determined based on the vehicle speed, the front wheel steering angle, the rear wheel steering angle, the rear wheel track, and the stability factor. The feedback rear wheel rotation rate is determined based on the desired yaw rate and the actual yaw rate.

2. The rear-wheel steering control method according to claim 1, characterized in that, The process of determining the feedforward rear wheel steering rate based on the actual rear wheel steering rate and the correction coefficient includes: Obtain the vehicle's current rear-wheel steering mode; The correction coefficient is determined based on the rear wheel steering pattern; The actual rear wheel steering rate is corrected based on the correction coefficient to obtain the feedforward rear wheel steering rate.

3. The rear-wheel steering control method according to claim 2, characterized in that, The step of correcting the actual rear wheel steering angle rate based on the correction coefficient to obtain the feedforward rear wheel steering angle rate includes: The feedforward rear wheel angular rate is obtained by multiplying the actual rear wheel angular rate by the correction coefficient.

4. The rear-wheel steering control method according to claim 1, characterized in that, The step of determining the feedback rear wheel steering rate based on the desired yaw rate and the actual yaw rate includes: Calculate the difference between the desired yaw rate and the actual yaw rate to obtain the yaw rate difference; The yaw rate difference is adjusted using PID control to obtain the feedback rear wheel rotation rate.

5. The rear-wheel steering control method according to claim 1, characterized in that, Determining the target rear wheel steering rate based on the feedforward rear wheel steering rate and the feedback rear wheel steering rate includes: The target rear wheel angular rate is obtained by calculating the sum of the feedforward rear wheel angular rate and the feedback rear wheel angular rate.

6. The rear-wheel steering control method according to any one of claims 1-5, characterized in that, The rear wheel steering control method further includes: Upon receiving a rear-wheel steering mode request, determine whether the conditions for switching rear-wheel steering mode are met based on the vehicle's status parameters and driving parameters. If it is determined that the conditions for switching the rear wheel steering mode are met, respond to the rear wheel steering mode request.

7. A rear-wheel steering control device, characterized in that, include: The feedforward module is used to determine the feedforward rear wheel angular rate based on the actual rear wheel angular rate and the correction coefficient when the rear wheel steering function is on. The correction factor is the factor corresponding to the rear wheel steering mode; The feedback module is used to determine the feedback rear wheel steering rate based on the vehicle's driving parameters and the vehicle's body parameters. The target rear wheel steering rate determination module is used to determine the target rear wheel steering rate based on the feedforward rear wheel steering rate and the feedback rear wheel steering rate. The vehicle's driving parameters include vehicle speed, actual yaw rate, front wheel steering angle, and rear wheel steering angle; the vehicle's body parameters include vehicle weight, front and rear wheelbase, front and rear axle stiffness, and rear wheel track. Determining the feedback rear wheel steering rate based on the vehicle's driving parameters and body parameters includes: The stability factor is determined based on the vehicle weight, the front and rear wheelbase, and the front and rear axle stiffness. The desired yaw rate is determined based on the vehicle speed, the front wheel steering angle, the rear wheel steering angle, the rear wheel track, and the stability factor. The feedback rear wheel rotation rate is determined based on the desired yaw rate and the actual yaw rate.

8. A vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.

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