Steering control method and device combined with road adhesion characteristics, medium and product

Abstract

The embodiment of the invention provides a steering control method and device combined with road adhesion characteristics, a medium and a product. The method comprises the steps that the average deceleration of a vehicle in the braking process is obtained, a road adhesion coefficient is estimated according to the average deceleration, the road adhesion coefficient and the average deceleration are positively correlated, a corresponding adhesion correction factor is determined according to the road adhesion coefficient, and the adhesion correction factor and the road adhesion coefficient are negatively correlated; correcting a first target rotating speed of a steering wheel motor of the vehicle according to the attachment correction factor to obtain a second target rotating speed of the steering wheel motor, and performing torque control on the steering wheel motor according to the second target rotating speed and the actual rotating speed of the steering wheel motor. According to the method, the torque of the steering wheel motor is controlled according to the corrected rotating speed and the actual rotating speed of the steering wheel motor, so that the steering angle under different road surface characteristics is accurately controlled, and the driving safety is ensured.

Description

Technical Field

[0001] The present application relates to the field of autonomous driving technology, and in particular to a steering control method, device, medium and product combined with road adhesion characteristics. Background Art

[0002] As an important trend in the development of vehicle intelligence, the core of autonomous driving technology is to realize autonomous navigation and control of vehicles. Among them, steering angle control is one of the key technologies in autonomous driving technology, which directly determines the curvature and direction of the vehicle's driving path, and affects the friction distribution between the tires and the ground and the synergy of the suspension system, and is directly related to the vehicle's driving trajectory and stability.

[0003] In the prior art, the target speed is calculated through the angle PID control closed loop according to the deviation between the requested steering angle and the current angle of the vehicle, and then the angular velocity PID control closed loop is further accurately adjusted according to the deviation between the target speed and the current speed of the vehicle steering system motor to obtain the required torque value. Then, the feedforward torque value is calculated based on the comparison between the target speed and the current state of the motor, and finally the final output torque value is obtained by filtering the torque values ​​of the PID control output and the feedforward compensation output, thereby achieving precise control of the vehicle steering angle.

[0004] However, the steering angle control method in the prior art does not take into account the impact of road surface characteristics on the steering angle. The friction coefficient, hardness, flatness and other characteristics of different road surfaces vary greatly, resulting in inaccurate steering angle control on different road surfaces, ultimately affecting driving safety. Summary of the invention

[0005] The steering control method, device, medium and product combined with the road adhesion characteristics provided in the embodiments of the present application are used to achieve accurate vehicle steering angle control on roads with different characteristics to ensure driving safety.

[0006] In a first aspect, an embodiment of the present application provides a steering control method in combination with road adhesion characteristics, including:

[0007] Obtaining an average deceleration of the vehicle during braking to estimate a road adhesion coefficient according to the average deceleration, wherein the road adhesion coefficient is positively correlated with the average deceleration;

[0008] Determining a corresponding adhesion correction factor according to the road adhesion coefficient, wherein the adhesion correction factor is negatively correlated with the road adhesion coefficient;

[0009] Correcting a first target speed of a steering wheel motor of the vehicle according to the adhesion correction factor to obtain a second target speed of the steering wheel motor;

[0010] The steering wheel motor is torque controlled according to the second target speed and the actual speed of the steering wheel motor.

[0011] In a possible implementation manner, estimating the road adhesion coefficient according to the average deceleration includes:

[0012] The product of the average deceleration and a preset coefficient of the vehicle during braking is determined as the road adhesion coefficient.

[0013] In a possible implementation manner, the correcting the first target speed of the steering wheel motor of the vehicle according to the adhesion correction factor to obtain the second target speed of the steering wheel motor includes:

[0014] determining a third target rotation speed of the steering wheel motor according to a deviation between a target steering angle of the steering wheel of the vehicle and an actual angle of the steering wheel, wherein the deviation is positively correlated with the third target rotation speed;

[0015] The third target speed is corrected by the steering wheel torque and the current vehicle speed of the vehicle to obtain the first target speed of the steering wheel motor, wherein the first target speed is positively correlated with the steering wheel torque and negatively correlated with the current vehicle speed;

[0016] The product of the adhesion correction factor and the first target speed is used as the second target speed.

[0017] In a possible implementation manner, obtaining the average deceleration of the vehicle during braking includes:

[0018] Acquiring state information of the vehicle during braking, the state information including: vehicle speed at the start of braking and deceleration at multiple moments during braking;

[0019] According to the braking starting speed and the decelerations at the multiple moments, the vehicle speeds corresponding to the multiple moments are determined in turn, so as to determine the average deceleration according to the vehicle speeds at each moment, wherein the vehicle speed at the i-th moment is obtained by decelerating the vehicle speed at the i-1th moment by the deceleration at the i-1th moment for a preset time period, and the preset time period is the time interval between the i-1th moment and the i-th moment, and i is a positive integer greater than or equal to 1, and the braking starting speed is the vehicle speed at the 0th moment.

[0020] In a possible implementation manner, determining the average deceleration according to the vehicle speed at each of the moments includes:

[0021] Calculating the difference between the vehicle speed at each moment and the vehicle speed at the last moment as the equivalent vehicle speed at each moment;

[0022] Taking the last moment as the origin of the two-dimensional coordinate system, fitting the speed curve formed by the vehicle at the multiple moments according to the equivalent vehicle speed at each moment;

[0023] The slope of the vehicle speed curve is taken as the average deceleration.

[0024] In a possible implementation manner, the acquiring the state information of the vehicle during the braking process includes:

[0025] Receiving a brake signal sent by a controller area network (CAN) of the vehicle through a preset brake signal receiving event;

[0026] When the braking signal indicates that the vehicle is in a braking state, recording the braking state;

[0027] Receiving the vehicle speed signal sent by the CAN network through a preset vehicle speed signal receiving event;

[0028] When the vehicle is in a braking state and the vehicle speed signal is the first vehicle speed signal in the braking state, recording the vehicle speed in the vehicle speed signal as the braking start vehicle speed;

[0029] Receiving the acceleration signal sent by the CAN network through a preset acceleration signal receiving event;

[0030] When the vehicle is in a braking state, the acceleration in the acceleration signal is used as the deceleration and recorded at the corresponding time;

[0031] The method further comprises:

[0032] When the braking signal indicates that the vehicle is in a braking end state, or the vehicle speed in the vehicle speed signal is 0, the step of determining the vehicle speeds corresponding to the multiple moments in sequence according to the braking starting speed and the decelerations at the multiple moments is entered, so as to determine the average deceleration according to the vehicle speeds at each moment.

[0033] In a second aspect, an embodiment of the present application provides a steering control device in combination with road adhesion characteristics, comprising:

[0034] An acquisition module, used for acquiring an average deceleration of the vehicle during braking, so as to estimate a road adhesion coefficient according to the average deceleration, wherein the road adhesion coefficient is positively correlated with the average deceleration;

[0035] A processing module, configured to determine a corresponding adhesion correction factor according to the road adhesion coefficient, wherein the adhesion correction factor is negatively correlated with the road adhesion coefficient;

[0036] The processing module is further used to correct a first target speed of the steering wheel motor of the vehicle according to the adhesion correction factor to obtain a second target speed of the steering wheel motor;

[0037] The processing module is further used to perform torque control on the steering wheel motor according to the second target speed and the actual speed of the steering wheel motor.

[0038] In a steering control device incorporating road adhesion characteristics, the present invention also includes:

[0039] The processing module is used to determine the product of the average deceleration and a preset coefficient of the vehicle during braking as the road adhesion coefficient.

[0040] In a steering control device incorporating road adhesion characteristics, the present invention also includes:

[0041] a processing module, configured to determine a third target rotation speed of the steering wheel motor according to a deviation between a target steering angle of the steering wheel of the vehicle and an actual angle of the steering wheel, wherein the deviation is positively correlated with the third target rotation speed;

[0042] The processing module is further used to correct the third target speed according to the steering wheel torque and the current vehicle speed of the vehicle to obtain the first target speed of the steering wheel motor, wherein the first target speed is positively correlated with the steering wheel torque and negatively correlated with the current vehicle speed;

[0043] The processing module is further configured to use the product of the adhesion correction factor and the first target speed as the second target speed.

[0044] In a steering control device incorporating road adhesion characteristics, the present invention also includes:

[0045] An acquisition module, used for acquiring state information of the vehicle during the braking process, wherein the state information includes: a vehicle speed at the start of braking and decelerations at multiple moments during the braking process;

[0046] A processing module is used to determine the vehicle speeds corresponding to the multiple moments in sequence according to the braking starting speed and the decelerations at the multiple moments, so as to determine the average deceleration according to the vehicle speeds at each moment, wherein the vehicle speed at the i-th moment is obtained by decelerating the vehicle speed at the i-1th moment by a preset time length by the deceleration at the i-1th moment, the preset time length is the time interval between the i-1th moment and the i-th moment, i is a positive integer greater than or equal to 1, and the braking starting speed is the vehicle speed at the 0th moment.

[0047] In a steering control device incorporating road adhesion characteristics, the present invention also includes:

[0048] A processing module, used for calculating the difference between the vehicle speed at each moment and the vehicle speed at the last moment as the equivalent vehicle speed at each moment;

[0049] The processing module is further used to fit the vehicle speed curve formed by the vehicle at the multiple moments according to the equivalent vehicle speed at each moment, taking the last moment as the origin of the two-dimensional coordinate system;

[0050] The processing module is further configured to use the slope of the vehicle speed curve as the average deceleration.

[0051] In a steering control device incorporating road adhesion characteristics, the present invention also includes:

[0052] A processing module, used for receiving a brake signal sent by a controller area network (CAN) of the vehicle through a preset brake signal receiving event;

[0053] The processing module is further configured to record the braking state when the braking signal indicates that the vehicle is in a braking state;

[0054] The processing module is further used to receive the vehicle speed signal sent by the CAN network through a preset vehicle speed signal receiving event;

[0055] The processing module is further configured to record the vehicle speed in the vehicle speed signal as the braking start speed when the vehicle is in a braking state and the vehicle speed signal is the first vehicle speed signal in the braking state;

[0056] The processing module is further used to receive the acceleration signal sent by the CAN network through a preset acceleration signal receiving event;

[0057] The processing module is further used to record the acceleration in the acceleration signal as deceleration and the corresponding time when the vehicle is in a braking state;

[0058] The processing module is also used to enter the step of determining the vehicle speeds corresponding to the multiple moments in sequence according to the braking starting speed and the decelerations at the multiple moments when the braking signal indicates that the vehicle is in a braking end state or the vehicle speed in the vehicle speed signal is 0, so as to determine the average deceleration according to the vehicle speed at each moment.

[0059] In a third aspect, an embodiment of the present application provides an electronic device, including: a memory, a processor;

[0060] The memory stores computer-executable instructions;

[0061] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0062] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementations of the first aspect.

[0063] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0064] The steering control method, device, medium and product combined with the road adhesion characteristics provided in the embodiment of the present application obtain the average deceleration of the vehicle during the braking process to estimate the road adhesion coefficient according to the average deceleration, and then determine the corresponding adhesion correction factor according to the road adhesion coefficient, and finally correct the first target speed of the steering wheel motor of the vehicle according to the adhesion correction factor to obtain the second target speed of the steering wheel motor, and perform torque control on the steering wheel motor according to the second target speed and the actual speed of the steering wheel motor. Compared with the prior art, which directly performs feedforward compensation by two-stage PID control of angle and angular velocity combined with a feedforward control module, and obtains the final torque value with the assistance of filtering calculation, the present application obtains the average deceleration of the vehicle during the braking process, calculates the road adhesion coefficient according to the average deceleration, and then obtains the correction factor according to the road adhesion coefficient, corrects the speed on the road with different adhesion characteristics, and then controls the steering wheel motor according to the corrected speed and the actual speed of the steering wheel motor, so as to achieve accurate control of the steering angle under different road characteristics and ensure driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0066] Figure 1 A schematic diagram of a scenario of a steering control method combined with road adhesion characteristics provided in this application;

[0067] Figure 2 A schematic flow chart of a first embodiment of a steering control method combining road adhesion characteristics provided by the present application;

[0068] Figure 3 A schematic flow chart of a second embodiment of a steering control method combining road adhesion characteristics provided by the present application;

[0069] Figure 4 A schematic flow chart of a third embodiment of a steering control method combining road adhesion characteristics provided by the present application;

[0070] Figure 5 A schematic flow chart of a fourth embodiment of a steering control method combining road adhesion characteristics provided by the present application;

[0071] Figure 6 A schematic flow chart of a fifth embodiment of a steering control method combining road adhesion characteristics provided by the present application;

[0072] Figure 7 A schematic diagram of the structure of a steering control device combined with road adhesion characteristics provided in this application;

[0073] Figure 8 A schematic diagram of the structure of the electronic device provided in this application.

[0074] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0075] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0076] 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, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with the relevant laws, regulations and standards of the relevant countries and regions, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0077] In the prior art, feedforward compensation is performed through two-level PID control of angle and angular velocity combined with a feedforward control module, and the torque value obtained with the assistance of filtering calculation is not considered the influence of different road adhesion characteristics on the obtained torque value. As a result, the steering angle control is inaccurate on different road surfaces, which ultimately affects driving safety.

[0078] Based on this, the inventive concept of the present application is to provide a steering control method combined with road adhesion characteristics. By considering the adhesion characteristics of different road surfaces, the road adhesion characteristics are used as a factor in calculating the final torque value to offset the influence of different road surfaces on the final torque value. Therefore, by obtaining the average deceleration of the vehicle during braking, the road adhesion coefficient is determined according to the average deceleration, and the correction factor is determined according to the road adhesion coefficient. The rotation speed on roads with different adhesion characteristics is corrected, and then the steering wheel motor is torque controlled according to the corrected rotation speed and the actual rotation speed of the steering wheel motor to achieve accurate control of the steering angle under different road characteristics and ensure driving safety.

[0079] Figure 1 A schematic diagram of a scenario of a steering control method combined with road adhesion characteristics provided in this application, such as Figure 1 As shown, during the driving process of the vehicle, the steering angle of the wheel is changed by turning the steering wheel to achieve the steering operation of the vehicle. For different road surfaces, the present application obtains different road adhesion coefficients, determines the corresponding correction factor according to the road adhesion coefficient, corrects the speed of the steering wheel motor, and then controls the steering wheel motor torque to achieve the steering angle control correction of the vehicle in the form of different road adhesion characteristics, thereby ensuring that the steering angle is accurately controlled under different road characteristics.

[0080] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0081] Figure 2 A schematic diagram of a flow chart of a first embodiment of a steering control method combining road adhesion characteristics provided by the present application, such as Figure 1 As shown, the method comprises the following steps:

[0082] S201: Obtain an average deceleration of the vehicle during braking to estimate a road adhesion coefficient based on the average deceleration. The road adhesion coefficient is positively correlated with the average deceleration.

[0083] In an embodiment of the present application, the average deceleration of the vehicle during braking is obtained, and the road adhesion coefficient is estimated based on the average deceleration. The road adhesion coefficient is positively correlated with the average deceleration.

[0084] Preferably, a specific implementation method of estimating the road adhesion coefficient based on the average deceleration is: multiplying the average deceleration and a preset coefficient of the vehicle during braking to determine the road adhesion coefficient.

[0085] In the embodiment of the present application, the product of the average deceleration of the vehicle during the braking process and the preset coefficient of the vehicle during the braking process is determined as the road adhesion coefficient, that is:

[0086]

[0087] Among them, k is an empirical value and can be calibrated. is the average deceleration, F is the road adhesion coefficient, and the larger F is, the rougher and drier the road surface is, and the better the road adhesion characteristics are.

[0088] S202: Determine a corresponding adhesion correction factor according to the road adhesion coefficient, where the adhesion correction factor is negatively correlated with the road adhesion coefficient.

[0089] In the embodiment of the present application, the corresponding adhesion correction factor is determined according to the road adhesion coefficient, and the adhesion correction factor is negatively correlated with the road adhesion coefficient. Optionally, the adhesion correction factor corresponding to the road adhesion coefficient is determined by looking up a table or formula.

[0090] The road adhesion coefficient and adhesion correction factor table are preset, where the road adhesion coefficient is: =[ ], the adhesion correction factor is: =[ ], M is the index range of the table lookup.

[0091] Alternatively, the adhesion correction factor is determined by the formula:

[0092]

[0093] in, and b are constants, which can be calibrated according to actual conditions, F is the road adhesion coefficient, and K is the adhesion correction factor. It should be noted that the formula can be adjusted based on experience.

[0094] S203: Correcting a first target speed of a steering wheel motor of the vehicle according to the adhesion correction factor to obtain a second target speed of the steering wheel motor.

[0095] In the embodiment of the present application, the first target speed of the steering wheel of the vehicle is corrected according to the adhesion correction factor to obtain the second target speed of the steering wheel motor.

[0096] S204: Perform torque control on the steering wheel motor according to the second target speed and the actual speed of the steering wheel motor.

[0097] In an embodiment of the present application, the steering wheel motor is subjected to torque control according to the second target speed and the actual speed of the steering wheel motor. For example, the output steering wheel motor torque is calculated by a proportional-integral-derivative (PID) control algorithm to perform torque control on the steering wheel motor. That is, the deviation between the second target speed and the actual speed of the steering wheel motor is calculated, and then the deviation is input into the PID control algorithm, and the PID control algorithm calculates the output steering wheel motor torque so that the steering wheel motor is subjected to torque control.

[0098] In the embodiment of the present application, the average deceleration of the vehicle during the braking process is obtained to estimate the road adhesion coefficient according to the average deceleration, and then the corresponding adhesion correction factor is determined according to the road adhesion coefficient, and finally the first target speed of the steering wheel motor of the vehicle is corrected according to the adhesion correction factor to obtain the second target speed of the steering wheel motor, and the steering wheel motor is torque controlled according to the second target speed and the actual speed of the steering wheel motor. Compared with the prior art, which directly performs feedforward compensation by two-stage PID control of angle and angular velocity combined with a feedforward control module, and obtains the final torque value with the assistance of filtering calculation, the present application obtains the average deceleration of the vehicle during the braking process, calculates the road adhesion coefficient according to the average deceleration, and then obtains the correction factor according to the road adhesion coefficient, corrects the speed on the road with different adhesion characteristics, and then controls the steering wheel motor according to the corrected speed and the actual speed of the steering wheel motor, so as to achieve accurate control of the steering angle under different road characteristics and ensure driving safety.

[0099] Figure 3 A schematic diagram of a flow chart of a second embodiment of a steering control method combining road adhesion characteristics provided by the present application, such as Figure 3 As shown in the above Figure 2 Based on the illustrated embodiment, a specific implementation of step S203 is as follows:

[0100] S301: Determine a third target rotation speed of a steering wheel motor according to a deviation between a target steering angle of a steering wheel of a vehicle and an actual angle of the steering wheel, wherein the deviation is positively correlated with the third target rotation speed.

[0101] In an embodiment of the present application, the deviation between the target steering angle of the vehicle's steering wheel and the actual angle of the steering wheel is determined, and then the third target speed of the steering wheel motor is determined based on the deviation. For example, a table between the deviation and the third target speed of the steering wheel motor is pre-established, wherein the deviation and the third target speed are positively correlated, and finally the third target speed corresponding to the deviation is determined by looking up the table.

[0102] S302: Correcting the third target speed by the steering wheel torque and the current vehicle speed of the vehicle to obtain a first target speed of the steering wheel motor. The first target speed is positively correlated with the steering wheel torque and negatively correlated with the current vehicle speed.

[0103] In the embodiment of the present application, the third target speed is corrected by the steering wheel torque and the current vehicle speed of the vehicle to obtain the first target speed of the steering wheel motor. For example, by pre-establishing a corresponding relationship table of the steering wheel torque, the vehicle speed and the third target speed, wherein the first target speed is positively correlated with the steering wheel torque and negatively correlated with the current vehicle speed, the first target speed is finally determined according to the table.

[0104] S303: Taking the product of the adhesion correction factor and the first target speed as the second target speed.

[0105] In the embodiment of the present application, the obtained adhesion correction factor is multiplied by the first target speed to be used as the second target speed.

[0106] In an embodiment of the present application, a third target speed of the steering wheel motor is determined based on a deviation between a target steering angle of the vehicle's steering wheel and an actual angle of the steering wheel, and the deviation is positively correlated with the third target speed. The third target speed is then corrected by the vehicle's steering wheel torque and the current vehicle speed to obtain a first target speed of the steering wheel motor. Finally, the product of the adhesion correction factor and the first target speed is used as the second target speed. By introducing a correction factor, the first target speed can be corrected according to road conditions to obtain a second target speed, so that stable steering control can be maintained under different road conditions, reducing steering instability caused by changes in road adhesion.

[0107] Figure 4 A schematic diagram of a flow chart of a third embodiment of a steering control method combining road adhesion characteristics provided by the present application, such as Figure 3 As shown in the above Figure 2 or Figure 3 Based on the embodiment shown, the specific implementation method of obtaining the average deceleration of the vehicle during braking in step S201 is:

[0108] S401: Acquire status information of the vehicle during braking, where the status information includes: vehicle speed at the start of braking, and deceleration at multiple moments during braking.

[0109] In an embodiment of the present application, before obtaining the average deceleration of the vehicle during braking, the state information of the vehicle during braking is first obtained, wherein the state information includes: the starting speed of braking and the deceleration at multiple moments during braking.

[0110] S402: According to the braking starting speed and the decelerations at multiple moments, the vehicle speeds corresponding to the multiple moments are determined in sequence, so as to determine the average deceleration according to the vehicle speed at each moment, wherein the vehicle speed at the i-th moment is obtained by decelerating the vehicle speed at the i-1th moment by a preset time length by the deceleration at the i-1th moment, the preset time length is the time interval between the i-1th moment and the i-th moment, i is a positive integer greater than or equal to 1, and the braking starting speed is the vehicle speed at the 0th moment.

[0111] In the embodiment of the present application, the vehicle speeds corresponding to the multiple moments are determined in sequence according to the vehicle speed at the start of braking and the decelerations at multiple moments during braking. The vehicle speed at the i-th moment is obtained by decelerating the vehicle speed at the i-1th moment by a preset time length by the deceleration at the i-1th moment, and the preset time length is the time interval between the i-1th moment and the i-th moment. In order to reduce the influence of noise and burrs in the deceleration, before determining the vehicle speeds corresponding to the multiple moments in sequence, the decelerations at the multiple moments are convoluted to improve the accuracy of subsequent vehicle speed calculation.

[0112] The calculation formulas for the vehicle speeds corresponding to multiple moments are:

[0113]

[0114] in, is the vehicle speed at the i-th moment, is the vehicle speed at the i-1th moment, is the deceleration corresponding to the i-1th moment, is the time interval between the i-1th moment and the ith moment, i is a positive integer greater than or equal to 1, and the braking starting speed is the speed at the 0th moment.

[0115] When the vehicle speeds corresponding to multiple moments are obtained, the average deceleration is calculated according to the vehicle speeds corresponding to the multiple moments. Optionally, the average deceleration is obtained by dividing the difference between any two vehicle speeds by the time difference between the two speeds. For example, the average deceleration is calculated using the starting speed and the ending speed:

[0116]

[0117] in, is the average deceleration, To end the speed, is the starting speed, To end the moment, For the start time.

[0118] Alternatively, use the maximum and minimum vehicle speeds to calculate the average deceleration:

[0119]

[0120] in, is the average deceleration, is the maximum vehicle speed, is the minimum vehicle speed, is the time corresponding to the maximum vehicle speed, is the time corresponding to the minimum vehicle speed.

[0121] In the embodiment of the present application, the state information of the vehicle during the braking process is obtained, and the state information includes: the braking starting speed, the deceleration at multiple moments during the braking process, and the speeds corresponding to the multiple moments are determined in sequence according to the braking starting speed and the deceleration at multiple moments, so as to determine the average deceleration according to the speed at each moment. During the braking process, the deceleration of the vehicle will change due to various factors such as road conditions and tire conditions. Therefore, according to the deceleration obtained at multiple moments, the corresponding speed is calculated, and then the average deceleration calculated according to the speed at multiple moments is more accurate than the average deceleration calculated directly according to the deceleration at multiple moments.

[0122] Figure 5 A schematic flow chart of a fourth embodiment of a steering control method combining road adhesion characteristics provided by the present application, such as Figure 5 As shown in the above Figure 4 Based on the illustrated embodiment, a specific implementation method of determining the average deceleration according to the vehicle speed at each moment in step S402 is:

[0123] S501: Calculate the difference between the vehicle speed at each moment and the vehicle speed at the last moment as the equivalent vehicle speed at each moment.

[0124] In an embodiment of the present application, when the vehicle speed corresponding to all moments is obtained, the difference between the vehicle speed at each moment and the vehicle speed at the last moment is calculated as the equivalent vehicle speed at each moment, so that the vehicle speed data at all moments have a unified reference benchmark relative to the vehicle speed at the end of braking.

[0125] S502: Taking the last moment as the origin of the two-dimensional coordinate system, fitting a vehicle speed curve formed at multiple moments according to the equivalent vehicle speed at each moment.

[0126] In the embodiment of the present application, the horizontal axis is the moment, the vertical axis is the equivalent vehicle speed, the last moment and its corresponding equivalent vehicle speed are used as the origin of the two-dimensional coordinate system, and the speed curve formed by the vehicle at multiple moments is fitted according to the equivalent vehicle speed at each moment, wherein polynomial fitting or spline difference fitting can be selected to fit the equivalent vehicle speed at each moment to obtain the speed curve.

[0127] S503: Taking the slope of the vehicle speed curve as the average deceleration.

[0128] In the embodiment of the present application, the slope of the vehicle speed curve is finally taken as the average deceleration.

[0129] In an embodiment of the present application, the difference between the vehicle speed at each moment and the vehicle speed at the last moment is calculated as the equivalent vehicle speed at each moment, which helps to reduce the complexity of subsequent calculation of the vehicle speed curve and the slope of the vehicle speed curve. The last moment is used as the origin of the two-dimensional coordinate system, making the subsequent process of calculating the slope according to the vehicle speed curve simpler. The speed curve formed by the vehicle at multiple moments is fitted according to the equivalent vehicle speed at each moment, and the slope of the vehicle speed curve is used as the average deceleration, thereby improving the accuracy of the average deceleration estimation.

[0130] Figure 6 A schematic diagram of a fifth embodiment of a steering control method combining road adhesion characteristics provided by the present application is shown in FIG. Figure 5 As shown in the above Figure 4 or Figure 5 Based on the embodiment shown, the specific implementation method of obtaining the state information of the vehicle during the braking process in step S401 is:

[0131] S601: Receive a brake signal sent by a controller area network (CAN) of a vehicle through a preset brake signal reception event.

[0132] In an embodiment of the present application, a brake signal receiving event is defined through a custom program function of a controller area network (CAN) tool, and then a brake signal sent by a controller area network CAN network of the vehicle is received through the brake signal receiving event.

[0133] S602: When the braking signal indicates that the vehicle is in a braking state, record the braking state.

[0134] In the embodiment of the present application, when the brake signal received by the brake signal receiving event indicates that the vehicle is in a braking state, that is, when the value of the received brake signal changes from 0 to 1, it indicates that the vehicle enters the braking state and the braking state is recorded.

[0135] S603: Receive a vehicle speed signal sent by the CAN network through a preset vehicle speed signal receiving event.

[0136] In the embodiment of the present application, similarly, through the custom program function of the CAN tool, a vehicle speed signal receiving event is defined, and the vehicle speed signal sent by the CAN network is received through the vehicle signal receiving event.

[0137] S604: When the vehicle is in a braking state and the vehicle speed signal is the first vehicle speed signal in the braking state, the vehicle speed in the vehicle speed signal is recorded as the braking start vehicle speed.

[0138] In an embodiment of the present application, when the braking signal received through the braking signal receiving event is 1, indicating that the vehicle is in a braking state, and the vehicle speed signal is the first vehicle speed signal in the braking state, the vehicle speed in the vehicle speed signal is recorded as the braking starting speed.

[0139] S605: Receive the acceleration signal sent by the CAN network through a preset acceleration signal receiving event.

[0140] In the embodiment of the present application, the acceleration signal receiving event is defined through the custom program function of the CAN tool, and the acceleration signal sent by the CAN network is received through the acceleration signal receiving event. Among them, by installing an acceleration sensor on the vehicle and connecting it to the vehicle CAN network, the acceleration signal detected by the acceleration sensor is sent to the CAN network, so that the acceleration signal receiving event receives the acceleration signal.

[0141] S606: When the vehicle is in a braking state, the acceleration in the acceleration signal is taken as the deceleration and recorded together with the corresponding time.

[0142] In the embodiment of the present application, when the vehicle is in a braking state, that is, when the value of the braking signal changes from 0 to 1, the acceleration in the acceleration signal is used as the deceleration, and the corresponding time is recorded in the deceleration list, that is, ],[ ,in, Refers to the time when the acceleration signal reception event is triggered. Refers to the magnitude of acceleration when the acceleration signal reception event is triggered. Indicates a list of deceleration rates.

[0143] S607: When the braking signal indicates that the vehicle is in the braking end state, or the vehicle speed in the speed signal is 0, enter the step of determining the vehicle speeds corresponding to multiple moments in sequence according to the braking start speed and the decelerations at multiple moments, so as to determine the average deceleration according to the vehicle speed at each moment.

[0144] In an embodiment of the present application, when the braking signal indicates that the vehicle is in a braking end state, that is, when the braking signal value changes from 1 to 0, or the vehicle speed in the vehicle speed signal is 0, the process enters a step of determining the vehicle speeds corresponding to multiple moments in sequence based on the braking starting speed and the decelerations at multiple moments, and determining the average deceleration based on the vehicle speed at each moment, and resetting the braking starting speed, the recorded deceleration, and the corresponding moment.

[0145] In an embodiment of the present application, a braking signal sent by a controller area network (CAN) of a vehicle is received through a preset braking signal receiving event. When the braking signal indicates that the vehicle is in a braking state, the braking state is recorded. A speed signal sent by the CAN network is received through a preset speed signal receiving event. When the vehicle is in a braking state and the speed signal is the first speed signal in the braking state, the speed in the speed signal is recorded as the braking start speed. An acceleration signal sent by the CAN network is received through a preset acceleration signal receiving event. When the vehicle is in a braking state, the acceleration in the acceleration signal is recorded as the deceleration and the corresponding time. When the braking signal indicates that the vehicle is in a braking end state or the speed in the speed signal is 0, the step of determining the speeds corresponding to the multiple moments in sequence according to the braking start speed and the decelerations at multiple moments is entered, so as to determine the average deceleration according to the speeds at each moment. The braking signal, speed signal and acceleration signal are received in real time through the CAN network, thereby ensuring the real-time and accuracy of the data, helping to accurately capture the dynamic changes in the vehicle braking process, and providing a reliable data basis for subsequent speed calculation and average deceleration determination.

[0146] Figure 7 A schematic diagram of the structure of a steering control device combined with road adhesion characteristics provided in this application, such as Figure 7 As shown, the present embodiment provides a steering control device 70 combined with road adhesion characteristics, including:

[0147] The acquisition module 701 is used to obtain the average deceleration of the vehicle during braking, so as to estimate the road adhesion coefficient according to the average deceleration, and the road adhesion coefficient is positively correlated with the average deceleration; the processing module 702 is used to determine the corresponding adhesion correction factor according to the road adhesion coefficient, and the adhesion correction factor is negatively correlated with the road adhesion coefficient; the processing module 702 is also used to correct the first target speed of the steering wheel motor of the vehicle according to the adhesion correction factor to obtain the second target speed of the steering wheel motor; the processing module 702 is also used to perform torque control on the steering wheel motor according to the second target speed and the actual speed of the steering wheel motor.

[0148] The steering control device combined with the road adhesion characteristics provided in this embodiment can execute the method provided in the above method embodiment, and its implementation principle and technical effect are similar, which will not be described in detail in this embodiment.

[0149] Figure 8 This is a schematic diagram of the structure of the electronic device provided in this application. Figure 8 As shown, the electronic device 80 provided in this embodiment includes: at least one processor 801 and a memory 802. Optionally, the device 80 also includes a communication component 803. The processor 801, the memory 802 and the communication component 803 are connected via a bus 804.

[0150] In a specific implementation process, at least one processor 801 executes the computer-executable instructions stored in the memory 802, so that at least one processor 801 executes the above method.

[0151] The specific implementation process of the processor 801 can be found in the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0152] In the above embodiments, it should be understood that the processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the invention can be directly implemented as a hardware processor, or can be implemented by a combination of hardware and software modules in the processor.

[0153] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk storage.

[0154] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of this application is not limited to only one bus or one type of bus.

[0155] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0156] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0157] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0158] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0159] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0160] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0161] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0162] If the function is implemented in the form of 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, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0163] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0164] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A steering control method in combination with road adhesion characteristics, characterized in that: include: Obtaining an average deceleration of the vehicle during braking to estimate a road adhesion coefficient according to the average deceleration, wherein the road adhesion coefficient is positively correlated with the average deceleration; Determining a corresponding adhesion correction factor according to the road adhesion coefficient, wherein the adhesion correction factor is negatively correlated with the road adhesion coefficient; Correcting a first target speed of a steering wheel motor of the vehicle according to the adhesion correction factor to obtain a second target speed of the steering wheel motor; The steering wheel motor is torque controlled according to the second target speed and the actual speed of the steering wheel motor.

2. The method according to claim 1, characterized in that The estimating the road adhesion coefficient according to the average deceleration comprises: The product of the average deceleration and a preset coefficient of the vehicle during braking is determined as the road adhesion coefficient.

3. The method according to claim 1, characterized in that The step of correcting the first target speed of the steering wheel motor of the vehicle according to the adhesion correction factor to obtain the second target speed of the steering wheel motor includes: determining a third target rotation speed of the steering wheel motor according to a deviation between a target steering angle of the steering wheel of the vehicle and an actual angle of the steering wheel, wherein the deviation is positively correlated with the third target rotation speed; The third target speed is corrected by the steering wheel torque and the current vehicle speed of the vehicle to obtain the first target speed of the steering wheel motor, wherein the first target speed is positively correlated with the steering wheel torque and negatively correlated with the current vehicle speed; The product of the adhesion correction factor and the first target speed is used as the second target speed.

4. The method according to any one of claims 1 to 3, characterized in that The obtaining of the average deceleration of the vehicle during braking comprises: Acquiring state information of the vehicle during braking, the state information including: vehicle speed at the start of braking and deceleration at multiple moments during braking; According to the braking starting speed and the decelerations at the multiple moments, the vehicle speeds corresponding to the multiple moments are determined in turn, so as to determine the average deceleration according to the vehicle speeds at each moment, wherein the vehicle speed at the i-th moment is obtained by decelerating the vehicle speed at the i-1th moment by the deceleration at the i-1th moment for a preset time period, and the preset time period is the time interval between the i-1th moment and the i-th moment, and i is a positive integer greater than or equal to 1, and the braking starting speed is the vehicle speed at the 0th moment.

5. The method according to claim 4, characterized in that Determining the average deceleration according to the vehicle speed at each of the moments includes: Calculating the difference between the vehicle speed at each moment and the vehicle speed at the last moment as the equivalent vehicle speed at each moment; Taking the last moment as the origin of the two-dimensional coordinate system, fitting the speed curve formed by the vehicle at the multiple moments according to the equivalent vehicle speed at each moment; The slope of the vehicle speed curve is taken as the average deceleration.

6. The method according to claim 5, characterized in that The obtaining of the state information of the vehicle during the braking process includes: Receiving a brake signal sent by a controller area network (CAN) of the vehicle through a preset brake signal receiving event; When the braking signal indicates that the vehicle is in a braking state, recording the braking state; Receiving the vehicle speed signal sent by the CAN network through a preset vehicle speed signal receiving event; When the vehicle is in a braking state and the vehicle speed signal is the first vehicle speed signal in the braking state, recording the vehicle speed in the vehicle speed signal as the braking start vehicle speed; Receiving the acceleration signal sent by the CAN network through a preset acceleration signal receiving event; When the vehicle is in a braking state, the acceleration in the acceleration signal is used as the deceleration and recorded at the corresponding time; The method further comprises: When the braking signal indicates that the vehicle is in a braking end state, or the vehicle speed in the vehicle speed signal is 0, the step of determining the vehicle speeds corresponding to the multiple moments in sequence according to the braking starting speed and the decelerations at the multiple moments is entered, so as to determine the average deceleration according to the vehicle speeds at each moment.

7. A steering control device incorporating road adhesion characteristics, characterized in that: include: An acquisition module, used for acquiring an average deceleration of the vehicle during braking, so as to estimate a road adhesion coefficient according to the average deceleration, wherein the road adhesion coefficient is positively correlated with the average deceleration; A processing module, configured to determine a corresponding adhesion correction factor according to the road adhesion coefficient, wherein the adhesion correction factor is negatively correlated with the road adhesion coefficient; The processing module is further used to correct a first target speed of the steering wheel motor of the vehicle according to the adhesion correction factor to obtain a second target speed of the steering wheel motor; The processing module is further used to perform torque control on the steering wheel motor according to the second target speed and the actual speed of the steering wheel motor.

8. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 6 when being executed by a processor.

Images