Road surface self-adaptive steering control method and system

Abstract

The invention discloses a road surface self-adaptive steering control method and system, and relates to the technical field of vehicle steering, and the method comprises the following steps: calibrating a power assisting coefficient, a damping coefficient and a high-frequency gain parameter of a steering system for vehicle types with different driving forms under different road conditions, thereby obtaining a real vehicle calibration parameter table; calculating a wheel speed difference according to the obtained wheel speed signal of each wheel and the vehicle driving form; when the wheel speed difference and the torque of the steering wheel meet set conditions, corresponding calibration parameters are selected in the real vehicle calibration parameter table according to the wheel speed difference, so that the action of a steering system is controlled. The hand power of a driver is not obviously suddenly changed, and the safety performance of the whole vehicle is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle steering technology, in particular to a road surface adaptive steering control method and system. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] In the actual use of the current automobile, the following working conditions are often encountered: the front drive vehicle type single tire is pressed by a stone or passes through a concave-convex road to cause the tire to be suspended, the steering hand force suddenly becomes light, and the vehicle loses control in an emergency. The front axle of the front drive vehicle type has a low adhesion coefficient, and the rear axle has a high adhesion coefficient, the steering force suddenly becomes light, and the vehicle loses control in an emergency. The rear axle of the rear drive vehicle type has a low adhesion coefficient, and the front axle has a high adhesion coefficient, the steering produces drift or the vehicle is unstable. When the single tire of the four-wheel drive vehicle type is driven to the ground, the steering wheel hand force becomes light, and the obstacle passing situation has an unstable feeling.

[0004] In the actual driving process of the automobile, complex road conditions or uneven road adhesion coefficients are easy to cause the wheel speed difference, and the traditional EPS system often causes abnormal steering hand force or reduces the stability of the vehicle due to the lack of a targeted parameter adjustment mechanism. SUMMARY

[0005] In order to solve the above problems, the present application provides a road surface adaptive steering control method and system, which ensures that the driver's hand force does not produce obvious mutation and improves the safety performance of the vehicle.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: In a first aspect, the present application provides a road surface adaptive steering control method, comprising: Calibrating the assist coefficient, the damping coefficient and the high-frequency gain parameter of the steering system of the vehicle type in different driving forms under different road conditions, thereby obtaining a real vehicle calibration parameter table; According to the wheel speed signals of each wheel and the driving form of the vehicle, the wheel speed difference is calculated; When the wheel speed difference and the steering wheel torque meet the set conditions, the corresponding calibration parameters are selected in the real vehicle calibration parameter table according to the wheel speed difference, so as to control the action of the steering system.

[0007] As an optional implementation, if the driving form of the vehicle is a front drive vehicle type, the wheel speed differences of the left and right front wheels and the front and rear wheels are calculated; if the driving form of the vehicle is a rear drive vehicle type, the wheel speed differences of the rear left and right wheels and the front and rear wheels are calculated; if the driving form of the vehicle is a four-wheel drive vehicle type, the wheel speed differences of the left and right wheels are calculated.

[0008] As an optional implementation, the process of judging whether the wheel speed difference and the steering wheel torque meet the set conditions comprises: If the wheel speed difference between the front and rear wheels is greater than or equal to a set wheel speed threshold value, or the wheel speed difference between the left and right front wheels is greater than or equal to a set wheel speed threshold value, and the steering wheel torque is greater than or equal to a set torque threshold value, the selection of the calibration parameters is performed. If the wheel speed difference between the front and rear wheels is less than a set wheel speed threshold value, and the wheel speed difference between the left and right front wheels is less than a set wheel speed threshold value, or the steering wheel torque is less than a set torque threshold value, the selection of the calibration parameters is not performed.

[0009] As an optional embodiment, the process of judging whether the wheel speed difference and the steering wheel torque meet the set conditions comprises: If the wheel speed difference between the front and rear wheels is greater than or equal to a set wheel speed threshold value, and the steering wheel torque is greater than or equal to a set torque threshold value, the selection of the calibration parameters is performed. If the wheel speed difference between the front and rear wheels is less than a set wheel speed threshold value, or the steering wheel torque is less than a set torque threshold value, the selection of the calibration parameters is not performed.

[0010] As an optional embodiment, the process of judging whether the wheel speed difference and the steering wheel torque meet the set conditions comprises: If the wheel speed difference between the left and right wheels is greater than or equal to a set wheel speed threshold value, and the steering wheel torque is greater than or equal to a set torque threshold value, the selection of the calibration parameters is performed. If the wheel speed difference between the left and right wheels is less than a set wheel speed threshold value, or the steering wheel torque is less than a set torque threshold value, the selection of the calibration parameters is not performed.

[0011] As an optional embodiment, a torque filter is added to the torque input parameter in the process of controlling the action of the steering system.

[0012] As an optional embodiment, for the drift mode working condition of the rear-drive vehicle, a reverse assist force is applied at the end of the steering angle.

[0013] In a second aspect, the present application provides a road surface adaptive steering control system, comprising: A calibration module configured to calibrate the assist force coefficient, the damping coefficient and the high-frequency gain parameter of the steering system under different road conditions for vehicles of different drive forms, thereby obtaining a real vehicle calibration parameter table; A calculation module configured to calculate the wheel speed difference according to the wheel speed signals of the wheels and the drive form of the vehicle. A control module configured to select the corresponding calibration parameter according to the wheel speed difference in the real vehicle calibration parameter table when the wheel speed difference and the steering wheel torque meet the set conditions, so as to control the action of the steering system.

[0014] In a third aspect, the present application provides an electronic device comprising a memory and a processor, and computer instructions stored on the memory and running on the processor, when the computer instructions are run by the processor, the method of the first aspect is completed.

[0015] In a fourth aspect, the present application provides a computer readable storage medium for storing computer instructions, when the computer instructions are executed by the processor, the method of the first aspect is completed.

[0016] In a fifth aspect, the present application provides a computer program product comprising a computer program, when the computer program is executed by the processor, the method of the first aspect is completed.

[0017] Compared with the prior art, the present application has the following beneficial effects: The present application provides a road surface adaptive steering control method and system, based on the vehicle CAN network receiving wheel speed information, according to the wheel speed difference, steering torque and other information, reducing the assist ratio coefficient, increasing the damping, reducing the high frequency gain, and combining the corresponding filtering strategy, ensuring that the driver's hand force does not produce obvious mutation, and appropriately increasing the steering hand force of the vehicle when the wheel speed difference exists.

[0018] The present application provides a road surface adaptive steering control method and system, which ensures that the vehicle is in the extreme working condition of single-sided tire landing, driving wheel slip and offset mode, and appropriately suppresses the EPS motor, and combines the corresponding filtering module to ensure that the driver's hand force does not produce obvious mutation, and improves the safety performance of the vehicle.

[0019] The advantages of the additional aspects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be known by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only illustrate the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0021] Figure 1 The road surface adaptive steering control method flow chart provided for embodiment 1 of the present application is provided; Figure 2 The road surface adaptive steering control method principle diagram provided for embodiment 1 of the present application is provided; Figure 3 The control principle diagram of the existing steering system is provided. DETAILED DESCRIPTION

[0022] The application will be further described below with reference to the drawings and embodiments.

[0023] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0024] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the application will be limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless otherwise required by context, singular terms shall include pluralities and vice versa. It will be further understood that the terms "comprises" and "comprising," when used in this specification, specify the presence of stated features, integers, steps, or components but do not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.

[0025] The embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0026] Embodiment 1 The embodiment provides a road surface adaptive steering control method, receives wheel speed information based on a vehicle CAN network, reduces a proportional coefficient of assistance, increases damping, reduces a high-frequency gain according to wheel speed difference, steering wheel torque and other information, and combines a corresponding filtering strategy to ensure that the steering force of a driver does not have obvious mutations and appropriately increases the steering force of the vehicle when there is a wheel speed difference.

[0027] As shown in Figure 1 , comprising: Calibrating the assistance coefficient, damping coefficient and high-frequency gain parameters of the steering system of a vehicle model with different driving forms under different road conditions to obtain a real vehicle calibration parameter table; According to the wheel speed signals of the wheels and the driving form of the vehicle, the wheel speed difference is calculated; When the wheel speed difference and the steering wheel torque meet the set conditions, the corresponding calibration parameters are selected from the real vehicle calibration parameter table according to the wheel speed difference to control the action of the steering system.

[0028] In the embodiment, first, the assistance coefficient, damping coefficient and high-frequency gain parameters of the steering system of a vehicle model with different driving forms are calibrated according to the speed, wheel speed, torque and other parameters of the vehicle under different road conditions, and a real vehicle calibration parameter table is obtained.

[0029] Specifically: The boost coefficient is stored according to different scenes of the real vehicle, and when the function is activated, the boost coefficient is output in combination with the vehicle speed, torque and rotation angle, and is superimposed with the original application layer boost output module.

[0030] The damping coefficient is stored according to different scenes of the real vehicle, and when the function is activated, the damping coefficient is output in combination with the vehicle speed, torque and rotation angle, and is superimposed with the original application layer boost damping module.

[0031] The high-frequency gain parameter is stored according to different scenes of the real vehicle, and when the function is activated, the high-frequency gain parameter is output in combination with the vehicle speed, torque and rotation angle, and is superimposed with the original application layer boost high-frequency gain module.

[0032] In the embodiment, in the process of driving the whole vehicle, the brake controller ESP sends the wheel speed signal to the whole vehicle CAN network through the CAN network in the case of inconsistent wheel slip rate of complex working conditions, and the steering system EPS receives the wheel speed signal through the CAN receiving module and calculates the corresponding wheel speed difference.

[0033] Specifically: For front drive vehicles, the wheel speed difference of the left and right front wheels and the front and rear wheels is calculated; For rear drive vehicles, the wheel speed difference of the left and right rear wheels and the front and rear wheels is calculated; For four-wheel drive vehicles, the wheel speed difference of the left and right wheels is calculated.

[0034] In the embodiment, it is judged whether the wheel speed difference and the steering wheel torque meet the set conditions, so as to determine whether to start the road self-adaptive steering control function.

[0035] Specifically: (1) For front drive vehicles: If the wheel speed difference of the front and rear wheels is greater than or equal to the set wheel speed threshold, or the wheel speed difference of the left and right front wheels is greater than or equal to the set wheel speed threshold, and the steering wheel torque is greater than or equal to the set torque threshold, the function is started; If the wheel speed difference of the front and rear wheels is less than the set wheel speed threshold and the wheel speed difference of the left and right front wheels is less than the set wheel speed threshold, or the steering wheel torque is less than the set torque threshold, the function is closed.

[0036] (2) For rear drive vehicles: If the wheel speed difference of the front and rear wheels is greater than or equal to the set wheel speed threshold, and the steering wheel torque is greater than or equal to the set torque threshold, the function is started; If the wheel speed difference of the front and rear wheels is less than the set wheel speed threshold, or the steering wheel torque is less than the set torque threshold, the function is closed.

[0037] (3) For four-wheel drive vehicles: If the difference in wheel speed between the left and right wheels is greater than or equal to the set wheel speed threshold, and the steering wheel torque is greater than or equal to the set torque threshold, then this function will be activated. If the difference in wheel speed between the left and right wheels is less than the set wheel speed threshold, or if the steering wheel torque is less than the set torque threshold, then this function will be turned off.

[0038] (4) When this function is turned on or off, the boost coefficient, damping coefficient, high-frequency gain parameter, and torque filter are also turned on or off simultaneously.

[0039] In this embodiment, when the wheel speed difference and steering wheel torque meet the set conditions, the corresponding calibration parameters of the assist coefficient, damping coefficient and high-frequency gain are selected in the actual vehicle calibration parameter table according to the wheel speed difference, based on the actual vehicle drive mode and different wheel speed difference conditions, and the locked calibration parameters are updated to the relevant modules in the EPS software.

[0040] like Figures 2-3 As shown, the calibrated assist coefficient, damping coefficient, and high-frequency gain parameters are superimposed on the original EPS control process, and torque input parameters are filtered to ensure a smooth transition in feel.

[0041] In this embodiment, for the drift mode of a rear-wheel drive vehicle, a reverse assist can be applied at the end of the steering angle, taking into account the actual driving scenario.

[0042] In this embodiment, the wheel speed signal is issued by the ESP controller, transmitted through the CAN network, received by the EPS controller, and the function logic is turned on or off based on the wheel speed signal status. The corresponding parameters are updated, and the torque filtering module is turned on or off synchronously.

[0043] The aforementioned adaptive steering control method receives wheel speed information via the vehicle's CAN network. Based on wheel speed differences and steering wheel torque, it reduces the power assist ratio, increases damping, and reduces high-frequency gain, combined with appropriate filtering strategies, to ensure that the driver's hand force does not change significantly. It also appropriately increases the steering hand force when wheel speed differences exist. When the vehicle is in extreme conditions such as single-wheel contact, drive wheel slippage, or drift mode, the EPS motor applies appropriate suppression, combined with corresponding filtering modules, to ensure that the driver's hand force does not change significantly, thus improving the overall vehicle safety performance.

[0044] Example 2 This embodiment provides a road surface adaptive steering control system, including: The calibration module is configured to calibrate the steering system's assist coefficient, damping coefficient, and high-frequency gain parameters for vehicles with different drive types under different road conditions, thereby obtaining a real vehicle calibration parameter table. The calculation module is configured to calculate the wheel speed difference based on the acquired wheel speed signals of each wheel and the vehicle's drive mode; The control module is configured to select the corresponding calibration parameter from the actual vehicle calibration parameter table based on the wheel speed difference when the wheel speed difference and steering wheel torque meet the set conditions, thereby controlling the action of the steering system.

[0045] It should be noted that the above modules correspond to the steps described in Embodiment 1, and the examples and application scenarios implemented by the above modules and the corresponding steps are the same, but are not limited to the content disclosed in Embodiment 1. It should also be noted that the above modules, as part of the system, can be executed in a computer system such as a set of computer-executable instructions.

[0046] In further embodiments, the following is also provided: An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in Embodiment 1. For brevity, further details are omitted here.

[0047] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0048] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0049] A computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in Embodiment 1.

[0050] The method in Example 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor. The software modules can reside in readily available storage media in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, a detailed description is not provided here.

[0051] A computer program product includes a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0052] The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, which execute in a device on a target real or virtual processor to perform the processes / methods described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or divided among program modules as needed. The machine-executable instructions for the program modules can execute within a local or distributed device. In a distributed device, the program modules can reside in both local and remote storage media.

[0053] The computer program code used to implement the methods of the present invention may be written in one or more programming languages. This computer program code may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the computer or other programmable data processing device, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a computer, partially on a computer, as a stand-alone software package, partially on a computer and partially on a remote computer, or entirely on a remote computer or server.

[0054] In the context of this invention, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and the like. Examples of signals may include electrical, optical, radio, sound, or other forms of propagation signals, such as carrier waves, infrared signals, etc.

[0055] Those skilled in the art will recognize that the units and algorithm steps described in connection with the various examples of this embodiment 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 invention.

[0056] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A road surface adaptive steering control method, characterized in that, include: The steering system's assist coefficient, damping coefficient, and high-frequency gain parameters were calibrated for different drive types of vehicles under various road conditions, thereby obtaining a real vehicle calibration parameter table. The wheel speed difference is calculated based on the acquired wheel speed signals of each wheel and the vehicle's drive mode. Once the wheel speed difference and steering wheel torque meet the set conditions, the corresponding calibration parameters are selected from the actual vehicle calibration parameter table based on the wheel speed difference, thereby controlling the steering system's operation.

2. The road surface adaptive steering control method as described in claim 1, characterized in that, If the vehicle is a front-wheel drive vehicle, calculate the wheel speed difference between the left and right front wheels and between the front and rear wheels; If the vehicle is a rear-wheel drive vehicle, calculate the wheel speed difference between the left and right rear wheels and the front and rear wheels; If the vehicle is a four-wheel drive model, then calculate the wheel speed difference between the left and right wheels.

3. The road surface adaptive steering control method as described in claim 2, characterized in that, The process of determining whether the wheel speed difference and steering wheel torque meet the set conditions includes: When the vehicle is a front-wheel drive vehicle, if the wheel speed difference between the front and rear wheels is greater than or equal to the set wheel speed threshold, or the wheel speed difference between the left and right front wheels is greater than or equal to the set wheel speed threshold, and the steering wheel torque is greater than or equal to the set torque threshold, then the calibration parameters are selected. If the wheel speed difference between the front and rear wheels is less than the set wheel speed threshold and the wheel speed difference between the left and right front wheels is less than the set wheel speed threshold, or if the steering wheel torque is less than the set torque threshold, then no calibration parameter selection is performed.

4. The road surface adaptive steering control method as described in claim 2, characterized in that, The process of determining whether the wheel speed difference and steering wheel torque meet the set conditions includes: When the vehicle is a rear-wheel drive model, if the wheel speed difference between the front and rear wheels is greater than or equal to the set wheel speed threshold, and the steering wheel torque is greater than or equal to the set torque threshold, then the calibration parameters are selected. If the difference in wheel speed between the front and rear wheels is less than the set wheel speed threshold, or if the steering wheel torque is less than the set torque threshold, then no calibration parameters will be selected.

5. The road surface adaptive steering control method as described in claim 2, characterized in that, The process of determining whether the wheel speed difference and steering wheel torque meet the set conditions includes: When the vehicle is a four-wheel drive model, if the difference in wheel speed between the left and right wheels is greater than or equal to the set wheel speed threshold, and the steering wheel torque is greater than or equal to the set torque threshold, then the calibration parameters are selected. If the difference in wheel speed between the left and right wheels is less than the set wheel speed threshold, or if the steering wheel torque is less than the set torque threshold, then no calibration parameter selection will be performed.

6. The road surface adaptive steering control method as described in claim 1, characterized in that, During the process of controlling the steering system's actions, torque filtering is added to the torque input parameters; For drift mode conditions of rear-wheel drive vehicles, reverse assistance is applied at the end of the steering angle.

7. A road surface adaptive steering control system, characterized in that, include: The calibration module is configured to calibrate the steering system's assist coefficient, damping coefficient, and high-frequency gain parameters for vehicles with different drive types under different road conditions, thereby obtaining a real vehicle calibration parameter table. The calculation module is configured to calculate the wheel speed difference based on the acquired wheel speed signals of each wheel and the vehicle's drive mode; The control module is configured to select the corresponding calibration parameter from the actual vehicle calibration parameter table based on the wheel speed difference when the wheel speed difference and steering wheel torque meet the set conditions, thereby controlling the action of the steering system.

8. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, perform the method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, perform the method described in any one of claims 1-6.

10. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the method described in any one of claims 1-6.

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