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

Abstract

This application provides a steering control method, device, medium, and product that incorporates road surface adhesion characteristics. The method includes: acquiring the average deceleration of a vehicle during braking; estimating the road surface adhesion coefficient based on the average deceleration (the road surface adhesion coefficient and average deceleration are positively correlated); determining a corresponding adhesion correction factor based on the road surface adhesion coefficient (the adhesion correction factor is negatively correlated with the road surface adhesion coefficient); correcting a first target rotational speed of the vehicle's steering wheel motor based on the adhesion correction factor to obtain a second target rotational speed of the steering wheel motor; and performing torque control on the steering wheel motor based on the second target rotational speed and the actual rotational speed of the steering wheel motor. This method achieves accurate steering angle control under different road surface characteristics by performing torque control on the steering wheel motor according to the corrected rotational speed and the actual rotational speed of the steering wheel motor, thus ensuring driving safety.

Description

Technical Field

[0001] This application relates to the field of autonomous driving technology, and in particular to a steering control method, device, medium, and product that incorporates road surface adhesion characteristics. Background Technology

[0002] As a crucial trend in the development of vehicle intelligence, autonomous driving technology focuses on enabling autonomous navigation and control. Steering angle control is a key technology in autonomous driving, directly determining the curvature and direction of the vehicle's path, influencing the distribution of friction between the tires and the ground, and affecting the coordinated action of the suspension system. Therefore, it directly impacts the vehicle's trajectory and stability.

[0003] In existing technology, the target speed is calculated using an angle PID control closed loop based on the deviation between the requested steering angle and the vehicle's current angle. Then, based on the deviation between the target speed and the current speed of the vehicle's steering system motor, an angular velocity PID control closed loop is used for further precise adjustment to obtain the required torque value. Next, by comparing the target speed with the current state of the motor, a feedforward torque value is calculated. Finally, the torque values ​​from the PID control output and the feedforward compensation output are filtered to obtain the final output torque value, thereby achieving precise control of the vehicle's steering angle.

[0004] However, existing steering angle control methods do not take into account the influence of road surface characteristics on steering angle. Different road surfaces have significant differences in friction coefficient, hardness, and smoothness, which leads to inaccurate steering angle control on different road surfaces and ultimately affects driving safety. Summary of the Invention

[0005] The steering control method, device, medium, and product based on road surface adhesion characteristics provided in this application are used to ensure accurate vehicle steering angle control on road surfaces with different characteristics, thereby guaranteeing driving safety.

[0006] In a first aspect, embodiments of this application provide a steering control method incorporating road surface adhesion characteristics, comprising:

[0007] The average deceleration of the vehicle during braking is obtained, and the road adhesion coefficient is estimated based on the average deceleration, wherein the road adhesion coefficient and the average deceleration are positively correlated.

[0008] A corresponding adhesion correction factor is determined based on the road surface adhesion coefficient, and the adhesion correction factor is negatively correlated with the road surface adhesion coefficient.

[0009] The first target speed of the steering wheel motor of the vehicle is corrected according to the attachment correction factor to obtain the second target speed of the steering wheel motor;

[0010] Based on the second target speed and the actual speed of the steering wheel motor, torque control is performed on the steering wheel motor.

[0011] In one possible implementation, estimating the road adhesion coefficient based on the average deceleration includes:

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

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

[0014] The third target speed of the steering wheel motor is determined based on the deviation between the target steering angle of the vehicle's steering wheel and the actual angle of the steering wheel, and the deviation is positively correlated with the third target speed.

[0015] The third target speed is corrected by the steering wheel torque and the current vehicle speed to obtain the 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.

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

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

[0018] The vehicle's state information during braking is obtained, including: initial braking speed and deceleration at multiple moments during braking.

[0019] Based on the braking start speed and the deceleration at the plurality of times, the vehicle speed corresponding to each of the plurality of times is determined sequentially, so as to determine the average deceleration based on the vehicle speed at each of the times. The vehicle speed at the i-th time is obtained by decelerating the vehicle speed at the (i-1)-th time by the deceleration at the (i-1)-th time for a preset duration. The preset duration is the time interval between the (i-1)-th time and the i-th time. The i-th time is a positive integer greater than or equal to 1. The braking start speed is the vehicle speed at the 0-th time.

[0020] In one possible implementation, determining the average deceleration based on the vehicle speed at each of the stated times includes:

[0021] Calculate the difference between the vehicle speed at each stated moment and the vehicle speed at the last stated moment, and use this difference as the equivalent vehicle speed at each stated moment;

[0022] Using the last stated moment as the origin of the two-dimensional coordinate system, the vehicle speed curve formed by the vehicle at the multiple moments is fitted based on the equivalent vehicle speed at each stated moment.

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

[0024] In one possible implementation, obtaining the vehicle's state information during braking includes:

[0025] The vehicle receives braking signals sent by the CAN network of its controller area network through a pre-set braking signal receiving event.

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

[0027] The vehicle speed signal sent by the CAN network is received through a pre-set 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, the vehicle speed in the vehicle speed signal is recorded as the braking start speed.

[0029] The acceleration signal sent by the CAN network is received through a pre-set acceleration signal receiving event;

[0030] When the vehicle is braking, the acceleration in the acceleration signal is used as deceleration and the corresponding time is recorded.

[0031] The method further includes:

[0032] When the braking signal indicates that the vehicle is in the braking end state, or when the vehicle speed in the vehicle speed signal is 0, the process proceeds to the step of determining the vehicle speed corresponding to each of the multiple time points according to the braking start speed and the deceleration at each of the multiple time points, so as to determine the average deceleration based on the vehicle speed at each of the multiple time points.

[0033] Secondly, embodiments of this application provide a steering control device that incorporates road surface adhesion characteristics, comprising:

[0034] The acquisition module is used to acquire the average deceleration of the vehicle during braking, so as to estimate the road adhesion coefficient based on the average deceleration, wherein the road adhesion coefficient and the average deceleration are positively correlated.

[0035] The processing module is used to determine the corresponding adhesion correction factor based on the road surface adhesion coefficient, wherein the adhesion correction factor is negatively correlated with the road surface adhesion coefficient.

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

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

[0038] The provided steering control device, which incorporates road surface adhesion characteristics, also includes:

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

[0040] The provided steering control device, which incorporates road surface adhesion characteristics, also includes:

[0041] The processing module is used to determine a third target rotational speed of the steering wheel motor based on the deviation between the target steering angle of the vehicle's steering wheel and the actual angle of the steering wheel, wherein the deviation is positively correlated with the third target rotational speed.

[0042] The processing module is also used to correct the third target rotation speed based on the steering wheel torque and the current vehicle speed to obtain the first target rotation speed of the steering wheel motor, wherein the first target rotation 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 between the attachment correction factor and the first target rotational speed as the second target rotational speed.

[0044] The provided steering control device, which incorporates road surface adhesion characteristics, also includes:

[0045] The acquisition module is used to acquire the vehicle's state information during the braking process, including: the initial braking speed and the deceleration at multiple moments during the braking process;

[0046] The processing module is used to sequentially determine the vehicle speed corresponding to each of the plurality of time moments based on the braking start speed and the deceleration at each of the plurality of time moments, so as to determine the average deceleration based on the vehicle speed at each of the plurality of time moments. The vehicle speed at the i-th time moment is obtained by decelerating the vehicle speed at the i-1-th time moment by the deceleration at the i-1-th time moment for a preset duration. The preset duration is the time interval between the i-1-th time moment and the i-th time moment, where i is a positive integer greater than or equal to 1, and the braking start speed is the vehicle speed at the 0-th time moment.

[0047] The provided steering control device, which incorporates road surface adhesion characteristics, also includes:

[0048] The processing module is used to calculate the difference between the vehicle speed at each time moment and the vehicle speed at the last time moment, as the equivalent vehicle speed at each time moment;

[0049] The processing module is also used to fit the vehicle speed curve formed by the vehicle at the multiple times based on the equivalent vehicle speed at each of the last said time as the origin of the two-dimensional coordinate system.

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

[0051] The provided steering control device, which incorporates road surface adhesion characteristics, also includes:

[0052] The processing module is used to receive the braking signal sent by the vehicle's CAN network through a pre-set braking signal receiving event;

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

[0054] The processing module is also used to receive the vehicle speed signal sent by the CAN network through a pre-set vehicle speed signal receiving event;

[0055] The processing module is also used 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 also used to receive acceleration signals sent by the CAN network through a pre-set acceleration signal receiving event;

[0057] The processing module is also 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 further configured to, when the braking signal indicates that the vehicle is in a braking end state, or when the vehicle speed in the vehicle speed signal is 0, proceed to the step of determining the vehicle speed corresponding to each of the plurality of times according to the braking start speed and the deceleration at the plurality of times, so as to determine the average deceleration according to the vehicle speed at each of the plurality of times.

[0059] Thirdly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0060] The memory stores computer-executable instructions;

[0061] The processor executes computer execution instructions stored in the memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0062] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0063] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0064] The steering control method, device, medium, and product based on road surface adhesion characteristics provided in this application obtains the average deceleration of the vehicle during braking, estimates the road surface adhesion coefficient based on the average deceleration, determines the corresponding adhesion correction factor based on the road surface adhesion coefficient, and finally corrects the first target speed of the vehicle's steering wheel motor based on the adhesion correction factor to obtain the second target speed of the steering wheel motor. Based on the second target speed and the actual speed of the steering wheel motor, torque control is performed on the steering wheel motor. Compared to the prior art, which directly uses two-stage PID control of angle and angular velocity combined with a feedforward control module for feedforward compensation and uses filtering calculations to assist in obtaining the final torque value, this application obtains the average deceleration of the vehicle during braking, calculates the road surface adhesion coefficient based on the average deceleration, obtains the correction factor based on the road surface adhesion coefficient, corrects the speed on roads with different adhesion characteristics, and then performs torque control on the steering wheel motor based on the corrected speed and the actual speed of the steering wheel motor. This achieves accurate steering angle control under different road surface characteristics, ensuring driving safety. Attached Figure Description

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

[0066] Figure 1 A schematic diagram of a scenario for the steering control method that incorporates road surface adhesion characteristics provided in this application;

[0067] Figure 2 A schematic flowchart of an embodiment of a steering control method combining road surface adhesion characteristics provided in this application;

[0068] Figure 3 A schematic flowchart of a second embodiment of a steering control method incorporating road surface adhesion characteristics provided in this application;

[0069] Figure 4 A schematic flowchart of a third embodiment of a steering control method incorporating road surface adhesion characteristics provided in this application;

[0070] Figure 5 A schematic flowchart of Embodiment 4 of a steering control method combining road surface adhesion characteristics provided in this application;

[0071] Figure 6 A schematic flowchart of Embodiment 5 of a steering control method incorporating road surface adhesion characteristics provided in this application;

[0072] Figure 7 A schematic diagram of a steering control device that incorporates road surface adhesion characteristics, provided for this application;

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

[0074] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0075] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this 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, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of the relevant data all comply with the relevant laws, regulations, and standards of the relevant countries and regions, have taken necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation access points for users to choose to authorize or refuse.

[0077] In existing technologies, the torque value is obtained by combining two-stage PID control of angle and angular velocity with a feedforward control module for feedforward compensation and using filtering calculation as an auxiliary method. However, the influence of different road surface adhesion characteristics on the obtained torque value is not considered. Therefore, the steering angle control is inaccurate on different road surfaces, which ultimately affects driving safety.

[0078] Based on this, the inventive concept of this application is to provide a steering control method that incorporates road surface adhesion characteristics. By considering the adhesion characteristics of different road surfaces, the road surface 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 surface adhesion coefficient is determined based on the average deceleration, and a correction factor is determined based on the road surface adhesion coefficient to correct the rotational speed on roads with different adhesion characteristics. Then, based on the corrected rotational speed and the actual rotational speed of the steering wheel motor, torque control is performed on the steering wheel motor to achieve accurate control of the steering angle under different road surface characteristics and ensure driving safety.

[0079] Figure 1 A schematic diagram of a scenario for the steering control method combining road surface adhesion characteristics provided in this application, such as... Figure 1 As shown, during vehicle operation, the steering wheel is turned to change the steering angle of the wheels, thereby achieving vehicle steering. For different road surfaces, this application obtains different road surface adhesion coefficients, determines the corresponding correction factor based on the road surface adhesion coefficient, corrects the speed of the steering wheel motor, and then controls the torque of the steering wheel motor to correct the steering angle control of the vehicle under different road surface adhesion characteristics, ensuring that the steering angle is accurately controlled under different road surface characteristics.

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

[0081] Figure 2 A flowchart illustrating an embodiment of a steering control method incorporating road surface adhesion characteristics provided in this application is shown below. Figure 1 As shown, the method includes the following steps:

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

[0083] In this embodiment of the 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 and the average deceleration are positively correlated.

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

[0085] In this embodiment, the product of the average deceleration of the vehicle during braking and a preset coefficient during braking is determined as the road adhesion coefficient, i.e.:

[0086]

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

[0088] S202: Determine the corresponding adhesion correction factor based on the road surface adhesion coefficient. The adhesion correction factor is negatively correlated with the road surface adhesion coefficient.

[0089] In this embodiment, the corresponding adhesion correction factor is determined based on the road surface adhesion coefficient, and the adhesion correction factor is negatively correlated with the road surface adhesion coefficient. Optionally, the adhesion correction factor corresponding to the road surface adhesion coefficient can be determined by looking up a table or formula.

[0090] A table of road surface adhesion coefficients and adhesion correction factors is pre-defined, where the road surface adhesion coefficient is: =[ The attachment correction factor is: =[ M represents the index range for the table lookup.

[0091] Alternatively, the adhesion correction factor can be determined using a formula:

[0092]

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

[0094] S203: Correct the first target speed of the vehicle's steering wheel motor according to the attachment correction factor to obtain the second target speed of the steering wheel motor.

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

[0096] S204: Based on the second target speed and the actual speed of the steering wheel motor, torque control is performed on the steering wheel motor.

[0097] In this embodiment, torque control of the steering wheel motor is performed based on a second target speed and the actual speed of the steering wheel motor. For example, a proportional-integral-derivative (PID) control algorithm is used to calculate the output torque of the steering wheel motor, thereby controlling the torque of the steering wheel motor. Specifically, the deviation between the second target speed and the actual speed of the steering wheel motor is calculated, and then this deviation is input into the PID control algorithm. The PID control algorithm calculates the output torque of the steering wheel motor, thus enabling torque control of the steering wheel motor.

[0098] In this embodiment, the average deceleration of the vehicle during braking is acquired to estimate the road surface adhesion coefficient. Then, a corresponding adhesion correction factor is determined based on the road surface adhesion coefficient. Finally, the first target speed of the steering wheel motor is corrected based on the adhesion correction factor to obtain a second target speed. Torque control of the steering wheel motor is then performed based on the second target speed and the actual speed of the steering wheel motor. Compared to the prior art, which directly uses two-stage PID control of angle and angular velocity combined with a feedforward control module for feedforward compensation, and relies on filtering calculations to obtain the final torque value, this application acquires the average deceleration of the vehicle during braking, calculates the road surface adhesion coefficient based on the average deceleration, obtains a correction factor based on the road surface adhesion coefficient, corrects the speed on roads with different adhesion characteristics, and then performs torque control of the steering wheel motor based on the corrected speed and the actual speed of the steering wheel motor. This ensures accurate steering angle control under different road surface characteristics and guarantees driving safety.

[0099] Figure 3 A flowchart illustrating a second embodiment of a steering control method incorporating road surface adhesion characteristics provided in this application is shown below. Figure 3 As shown above, in the above Figure 2 Based on the illustrated embodiment, one specific implementation of step S203 is as follows:

[0100] S301: Based on the deviation between the target steering angle of the vehicle's steering wheel and the actual steering wheel angle, the third target speed of the steering wheel motor is determined, and the deviation and the third target speed are positively correlated.

[0101] In this embodiment of the 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, by pre-establishing a table between the deviation and the third target speed of the steering wheel motor, where the deviation and the third target speed are positively correlated, the third target speed corresponding to the deviation is finally determined by looking up the table.

[0102] S302: The third target speed is corrected by the vehicle's steering wheel torque and current vehicle speed to obtain the 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 this embodiment, the third target speed is corrected by the vehicle's steering wheel torque and current vehicle speed to obtain the first target speed of the steering wheel motor. For example, a table of correspondence between steering wheel torque, vehicle speed, and the third target speed is pre-established, 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 then determined based on the table.

[0104] S303: The product between the attachment correction factor and the first target rotational speed is used as the second target rotational speed.

[0105] In this embodiment of the application, the obtained attachment correction factor is multiplied by the first target rotational speed, and the result is used as the second target rotational speed.

[0106] In this embodiment, a third target speed of the steering wheel motor is determined based on the deviation between the target steering angle and the actual angle of the steering wheel. The deviation and the third target speed are positively correlated. Then, the third target speed is corrected by the steering wheel torque and the current vehicle speed to obtain the first target speed of the steering wheel motor. Finally, the product between the adhesion correction factor and the first target speed is used as the second target speed. By introducing the correction factor, the first target speed can be corrected according to the road conditions to obtain the 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 flowchart illustrating a third embodiment of a steering control method incorporating road surface adhesion characteristics provided in this application is shown below. Figure 3 As shown above, in the above Figure 2 or Figure 3 Based on the illustrated embodiment, the specific implementation method for obtaining the average deceleration of the vehicle during braking in step S201 is as follows:

[0108] S401: Obtain vehicle status information during braking, including: initial braking speed and deceleration at multiple moments during braking.

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

[0110] S402: Based on the initial braking speed and the deceleration at multiple times, determine the corresponding vehicle speeds at multiple times in sequence, so as to determine the average deceleration based on the vehicle speed at each time. The vehicle speed at the i-th time is obtained by decelerating the vehicle speed at the (i-1)-th time by the deceleration at the (i-1)-th time for a preset duration. The preset duration is the time interval between the (i-1)-th time and the i-th time, where i is a positive integer greater than or equal to 1. The initial braking speed is the vehicle speed at the 0-th time.

[0111] In this embodiment, the vehicle speed at multiple moments is determined sequentially based on the initial braking speed and the deceleration at multiple moments during braking. The vehicle speed at moment i is obtained by decelerating the vehicle speed at moment i-1 by the deceleration at moment i-1 for a preset time, where the preset time is the time interval between moment i-1 and moment i. To reduce the influence of noise and glitches in the deceleration, the deceleration at multiple moments is convolved before determining the vehicle speed at each moment, thereby improving the accuracy of subsequent vehicle speed calculations.

[0112] The formulas for calculating the vehicle speed at multiple moments are as follows:

[0113]

[0114] in, Let be the vehicle speed at time i. Let the speed of the vehicle be at time i-1. Let be the deceleration at time i-1. The time interval between the (i-1)th time and the ith time, where i is a positive integer greater than or equal to 1, and the braking starting speed is the speed at the 0th time.

[0115] When multiple vehicle speeds are obtained at different times, the average deceleration is calculated based on these speeds. Optionally, the average deceleration can be obtained by dividing the difference between any two vehicle speeds by the time difference between the two corresponding times. For example, the average deceleration can be calculated using the initial and final vehicle speeds.

[0116]

[0117] in, For average deceleration, To stop the vehicle speed, The initial vehicle speed, The end time, This is the start time.

[0118] Alternatively, the average deceleration can be calculated using the maximum and minimum vehicle speeds:

[0119]

[0120] in, For average deceleration, For maximum vehicle speed, Minimum speed, The time corresponding to the maximum vehicle speed. This represents the time corresponding to the minimum vehicle speed.

[0121] In this embodiment, the vehicle's state information during braking is acquired. This state information includes the initial braking speed and deceleration at multiple moments during braking. Based on the initial braking speed and the deceleration at each moment, the vehicle speed corresponding to each moment is sequentially determined, and the average deceleration is determined based on the vehicle speed at each moment. During braking, the vehicle's deceleration changes due to various factors such as road conditions and tire condition. Therefore, calculating the corresponding vehicle speed based on the deceleration acquired at multiple moments, and then calculating the average deceleration based on the vehicle speed at multiple moments, is more accurate than directly calculating the average deceleration based on the deceleration at multiple moments.

[0122] Figure 5 A flowchart illustrating Embodiment 4 of the steering control method incorporating road surface adhesion characteristics provided in this application is shown below. Figure 5 As shown above, in the above Figure 4 Based on the illustrated embodiment, a specific implementation method for determining the average deceleration according to the vehicle speed at each moment in step S402 is as follows:

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

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

[0125] S502: Using the last moment as the origin of the two-dimensional coordinate system, fit the vehicle speed curve formed by the vehicle at multiple moments based on the equivalent vehicle speed at each moment.

[0126] In this embodiment, the horizontal axis represents time and the vertical axis represents equivalent vehicle speed. The last time and its corresponding equivalent vehicle speed are used as the origin of the two-dimensional coordinate system. The vehicle speed curve formed by the vehicle at multiple times is fitted based on the equivalent vehicle speed at each time. Polynomial fitting and spline interpolation can be selected to fit the equivalent vehicle speed at each time to obtain the vehicle speed curve.

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

[0128] In this embodiment of the application, the slope of the vehicle speed curve is ultimately used as the average deceleration.

[0129] In this embodiment, 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. This helps to reduce the complexity of subsequent calculations of the vehicle speed curve and its slope. Furthermore, using the last moment as the origin of the two-dimensional coordinate system simplifies the subsequent calculation of the slope based on the vehicle speed curve. By fitting the vehicle speed curve formed by the vehicle at multiple moments based on the equivalent vehicle speed at each moment, and using the slope of the vehicle speed curve as the average deceleration, the accuracy of the average deceleration estimation is improved.

[0130] Figure 6 A flowchart illustrating Embodiment 5 of the steering control method incorporating road surface adhesion characteristics provided in this application is shown below. Figure 5 As shown above, in the above Figure 4 or Figure 5 Based on the illustrated embodiment, the specific implementation method for obtaining the vehicle's state information during the braking process in step S401 is as follows:

[0131] S601: Receives braking signals sent by the vehicle's CAN network via a pre-set braking signal reception event.

[0132] In this embodiment of the application, a braking signal reception event is defined using the custom program function of the Controller Area Network (CAN) tool, and then the braking signal sent by the vehicle's CAN network is received through the braking signal reception event.

[0133] S602: Record the braking status when the braking signal indicates that the vehicle is in a braking state.

[0134] In this embodiment of the application, when the brake signal received by the brake signal reception 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 has entered a braking state, and the braking state is recorded.

[0135] S603: Receives vehicle speed signals sent by the CAN network via a pre-set vehicle speed signal reception event.

[0136] Similarly, in this embodiment of the application, the vehicle speed signal reception event is defined through the custom program function of the CAN tool, and the vehicle speed signal sent by the CAN network is received through the vehicle signal reception 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 starting vehicle speed for braking.

[0138] In this embodiment of the application, when the brake signal received through the brake signal receiving event is 1, which indicates 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 start speed.

[0139] S605: Receives acceleration signals sent from the CAN network via a pre-set acceleration signal reception event.

[0140] In this embodiment, an acceleration signal reception event is defined using the custom program function of the CAN tool. This event receives acceleration signals transmitted from the CAN network. Specifically, an acceleration sensor is installed in the vehicle and connected to the vehicle's CAN network. The acceleration signal detected by the acceleration sensor is transmitted to the CAN network for the acceleration signal reception event to receive.

[0141] S606: When the vehicle is braking, the acceleration in the acceleration signal is used as deceleration and the corresponding time is recorded.

[0142] In this embodiment of the 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 deceleration, and the corresponding time is recorded in the deceleration list. ],[ ,in, This refers to the time when the acceleration signal reception event is triggered. This refers to the magnitude of acceleration when the acceleration signal reception event is triggered. This represents a list of decelerations.

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

[0144] In this embodiment of the application, when the braking signal indicates that the vehicle is in the braking end state, that is, when the braking signal value changes from 1 to 0, or when the vehicle speed in the vehicle speed signal is 0, the process proceeds to the step of determining the vehicle speed corresponding to each of the multiple times according to the braking start speed and the deceleration at multiple times, so as to determine the average deceleration according to the vehicle speed at each time, and resetting the braking start speed and the recorded deceleration and corresponding time.

[0145] In this embodiment, the vehicle's CAN network receives braking signals via a pre-set braking signal receiving event. When the braking signal indicates that the vehicle is in a braking state, the braking state is recorded. The vehicle speed signal received via the CAN network is received via a pre-set 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, the vehicle speed in the vehicle speed signal is recorded as the braking start speed. The acceleration signal received via the CAN network is received via a pre-set acceleration signal receiving event. When the vehicle is in a braking state, the acceleration in the acceleration signal is recorded as deceleration along with the corresponding time. When the braking signal indicates that the vehicle is in a braking end state, or when the vehicle speed in the vehicle speed signal is 0, the vehicle speed corresponding to multiple time points is determined sequentially based on the braking start speed and the deceleration at multiple time points. The average deceleration is then determined based on the vehicle speed at each time point. The real-time reception of braking signals, vehicle speed signals, and acceleration signals via the CAN network ensures the real-time nature and accuracy of the data, helping to accurately capture the dynamic changes during the vehicle braking process and providing a reliable data foundation for subsequent vehicle speed calculation and average deceleration determination.

[0146] Figure 7 A schematic diagram of a steering control device incorporating road surface adhesion characteristics is provided in this application, as shown below. Figure 7 As shown, the steering control device 70 that incorporates road surface adhesion characteristics provided in this embodiment includes:

[0147] The acquisition module 701 is used to acquire the average deceleration of the vehicle during braking, and to estimate the road adhesion coefficient based on the average deceleration. The road adhesion coefficient and the average deceleration are positively correlated. The processing module 702 is used to determine the corresponding adhesion correction factor based on the road adhesion coefficient. 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 vehicle's steering wheel motor based on 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 based on the second target speed and the actual speed of the steering wheel motor.

[0148] The steering control device that combines road surface adhesion characteristics provided in this embodiment can execute the method provided in the above-described method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0149] Figure 8 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 further includes a communication component 803. The processor 801, memory 802, and communication component 803 are connected via a bus 804.

[0150] In a specific implementation, at least one processor 801 executes computer execution instructions stored in memory 802, causing at least one processor 801 to perform the above-described method.

[0151] The specific implementation process of processor 801 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It 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 (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0153] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[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. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0155] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0156] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0157] The aforementioned 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 storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0158] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from 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 reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0159] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

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

[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 a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0163] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0164] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A steering control method incorporating road surface adhesion characteristics, characterized in that, include: The average deceleration of the vehicle during braking is obtained to estimate the road adhesion coefficient based on the average deceleration, wherein the road adhesion coefficient is positively correlated with the average deceleration; A corresponding adhesion correction factor is determined based on the road surface adhesion coefficient, and the adhesion correction factor is negatively correlated with the road surface adhesion coefficient. The first target speed of the steering wheel motor of the vehicle is corrected according to the attachment correction factor to obtain the second target speed of the steering wheel motor; Based on the second target speed and the actual speed of the steering wheel motor, torque control is performed on the steering wheel motor; The step of correcting the first target speed of the vehicle's steering wheel motor according to the attachment correction factor to obtain the second target speed of the steering wheel motor includes: The third target speed of the steering wheel motor is determined based on the deviation between the target steering angle of the vehicle's steering wheel and the actual angle of the steering wheel, and the deviation is positively correlated with the third target speed. The third target speed is corrected by the steering wheel torque and the current vehicle speed to obtain the 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. The product of the adhesion correction factor and the first target rotational speed is taken as the second target rotational speed.

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

3. The method according to claim 1 or 2, characterized in that, The acquisition of the vehicle's average deceleration during braking includes: The vehicle's state information during braking is obtained, including: initial braking speed and deceleration at multiple moments during braking. Based on the braking start speed and the deceleration at the plurality of times, the vehicle speed corresponding to each of the plurality of times is determined sequentially, so as to determine the average deceleration based on the vehicle speed at each of the times. The vehicle speed at the i-th time is obtained by decelerating the vehicle speed at the (i-1)-th time by the deceleration at the (i-1)-th time for a preset duration. The preset duration is the time interval between the (i-1)-th time and the i-th time. The i-th time is a positive integer greater than or equal to 1. The braking start speed is the vehicle speed at the 0-th time.

4. The method according to claim 3, characterized in that Determining the average deceleration based on the vehicle speed at each of the aforementioned times includes: Calculate the difference between the vehicle speed at each stated moment and the vehicle speed at the last stated moment, and use this difference as the equivalent vehicle speed at each stated moment; Using the last stated moment as the origin of the two-dimensional coordinate system, the vehicle speed curve formed by the vehicle at the multiple moments is fitted based on the equivalent vehicle speed at each stated moment. The slope of the vehicle speed curve is used as the average deceleration.

5. The method according to claim 4, characterized in that, The step of obtaining the vehicle's state information during braking includes: The vehicle receives braking signals sent by the CAN network of its controller area network through a pre-set braking signal receiving event. When the braking signal indicates that the vehicle is in a braking state, the braking state is recorded; The vehicle speed signal sent by the CAN network is received through a pre-set 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, the vehicle speed in the vehicle speed signal is recorded as the braking start speed. The acceleration signal sent by the CAN network is received through a pre-set acceleration signal receiving event; When the vehicle is braking, the acceleration in the acceleration signal is used as deceleration and the corresponding time is recorded. The method further includes: When the braking signal indicates that the vehicle is in the braking end state, or when the vehicle speed in the vehicle speed signal is 0, the process proceeds to the step of determining the vehicle speed corresponding to each of the multiple time points according to the braking start speed and the deceleration at each of the multiple time points, so as to determine the average deceleration based on the vehicle speed at each of the multiple time points.

6. A steering control device incorporating road surface adhesion characteristics, wherein the steering control device incorporating road surface adhesion characteristics is used to implement the steering control method incorporating road surface adhesion characteristics as described in any one of claims 1-5, characterized in that, include: The acquisition module is used to acquire the average deceleration of the vehicle during braking, so as to estimate the road adhesion coefficient based on the average deceleration, wherein the road adhesion coefficient and the average deceleration are positively correlated. The processing module is used to determine the corresponding adhesion correction factor based on the road surface adhesion coefficient, wherein the adhesion correction factor is negatively correlated with the road surface adhesion coefficient. The processing module is further configured to correct the first target speed of the steering wheel motor of the vehicle according to the attachment correction factor to obtain the second target speed of the steering wheel motor; The processing module is further configured to perform torque control on the steering wheel motor based on the second target speed and the actual speed of the steering wheel motor.

7. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-5.

9. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in any one of claims 1-5.

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