A rear-wheel steering calibration method and system matching a racetrack scene

Abstract

The present invention discloses a rear-wheel steering calibration method and system for matching a racetrack scene. The rear-wheel steering calibration method includes: when a vehicle enters the exit lap, judging the curve type based on a high-precision map and determining the direction of rear-wheel steering, the curve types including U-shaped curves and S-shaped compound curves, and the rear-wheel steering directions including same-direction steering and opposite-direction steering; when the vehicle enters the flight lap, calculating the yaw angle and lateral force required for the curve type based on vehicle driving data collected by vehicle sensors; determining a rear-wheel steering calibration strategy based on the rear-wheel steering direction, the yaw angle, the lateral force, and the vehicle model; and determining the rear-wheel steering follow-up angle and response rate based on the rear-wheel steering calibration strategy. This application can improve the efficiency of rear-wheel steering calibration, customize the racetrack, increase the vehicle's cornering speed, and thus improve lap time.

Description

Technical Field

[0001] The present application relates to the field of rear-wheel steering calibration, and in particular to a rear-wheel steering calibration method and system for matching a racetrack scene. Background Art

[0002] The general speed-dependent rear wheel steering calibration strategy of low-speed opposite direction and high-speed same direction cannot meet the vehicle's track scenario, and may also cause severe understeer when the vehicle passes through high-speed corners.

[0003] To achieve faster lap times, each corner on different tracks requires a separate rear-wheel steering strategy calibration. Furthermore, the calibration process needs to be repeated for each track, which is a labor-intensive and tedious process.

[0004] Rear-wheel steering calibration methods for conventional road driving conditions typically employ a strategy of counter-steering at low speeds to assist users with maneuvers such as U-turns. At higher speeds, a strategy of steering in the same direction helps the vehicle generate more lateral force, enabling lane changes while suppressing excess yaw angle, thereby enhancing high-speed driving stability and safety. However, the unique characteristics of racetracks, with their complex cornering conditions and the need for prolonged high-speed operation, place high demands on tire performance. Therefore, existing rear-wheel steering calibration methods for conventional road driving conditions are not applicable. Summary of the Invention

[0005] In order to solve the unreasonable problem of rear-wheel steering methods in track scenarios, this application proposes a rear-wheel steering calibration method that matches the track scenario, which can improve the efficiency of rear-wheel steering calibration, increase the vehicle's cornering speed, and thus increase lap time.

[0006] In a first aspect of the present application, a rear wheel steering calibration method matching a racetrack scene is provided, comprising:

[0007] When the vehicle enters the exit circle, the curve type is determined based on the high-precision map and the direction of rear wheel steering is determined. The curve types include U-shaped curves and S-shaped compound curves. The rear wheel steering directions include same-direction steering and opposite-direction steering.

[0008] When the vehicle enters the flight circle, the yaw angle and lateral force required for the type of curve are calculated based on vehicle driving data collected by vehicle sensors;

[0009] A rear wheel steering calibration strategy is determined based on the rear wheel steering direction, the yaw angle, the lateral force and the vehicle model, and a rear wheel steering follow-up angle and a response rate are determined according to the rear wheel steering calibration strategy.

[0010] Optionally, the rear wheel steering calibration method further includes:

[0011] Based on the high-precision map marking of the vehicle entering and exiting the corner, the rear wheel steering calibration strategy is modified based on the driver's driving habits, the vehicle entering and exiting the corner, wherein:

[0012] The driver's driving habits include:

[0013] The driver's reaction time, the driver's driving style;

[0014] When the driver enters the flying circle, the revised rear wheel steering calibration strategy is locked and uploaded to the cloud.

[0015] Optionally, the calculating the yaw angle and lateral force required for the curve type based on the vehicle driving data collected by the vehicle sensor includes:

[0016] Obtaining a current track model through a high-precision map, and obtaining a vehicle driving route based on the track model;

[0017] During a lap of the track based on the vehicle driving route, the vehicle's lateral acceleration signal, longitudinal acceleration signal, and yaw rate signal are obtained based on the vehicle's onboard gyroscope, a tire slip rate signal is obtained based on the wheel speed sensor, and a front and rear axle power distribution signal is obtained based on the power system;

[0018] The yaw angle and lateral force are obtained based on the lateral acceleration signal, the longitudinal acceleration signal, the yaw angular velocity signal, the tire slip ratio signal and the front and rear axle power distribution signal.

[0019] Optionally, when the vehicle enters the exit circle, before determining the type of curve and the direction of rear wheel steering based on the high-precision map, the process includes:

[0020] Perform rough positioning of the vehicle based on the HD map and detect whether there is a rear-wheel steering calibration strategy on the track;

[0021] If there is no rear-wheel steering calibration strategy, the type of curve is determined based on the high-precision map and the direction of rear-wheel steering is determined.

[0022] Optionally, before judging the curve type and determining the direction of rear wheel steering based on the high-precision map, the method further includes:

[0023] The vehicle must complete at least one lap of the race to familiarize itself with the track, warm up the tires, and lubricate the shock absorber fluid.

[0024] Optionally, the coarse positioning of the vehicle based on the high-precision map and the detection of whether there is a rear-wheel steering calibration strategy on the track include:

[0025] Determine the track the vehicle is on based on the rough positioning, and search the cloud for a rear-wheel steering calibration strategy for the track.

[0026] If the rear wheel steering calibration strategy for the track does not exist in the cloud, the data in the rear wheel steering calibration strategy is set to 0, and the rear wheels do not rotate with the front wheels.

[0027] Optionally, searching in the cloud whether a rear-wheel steering calibration strategy for the track exists further includes:

[0028] The cloud calibration strategy of the track is queried in the cloud and downloaded, and the cloud calibration strategy is modified when the vehicle enters the flight circle.

[0029] Optionally, querying the cloud calibration strategy of the track in the cloud and adaptively correcting the cloud calibration strategy when the vehicle enters the flight circle includes:

[0030] Using the cloud-based calibration strategy, and modifying the cloud-based calibration strategy based on the driver's driving habits, cornering speed, and cornering exit speed;

[0031] Use the revised cloud calibration strategy to enter the flight circle and calculate the lap speed;

[0032] If the current lap speed is higher than the cloud-calibrated lap speed, the rear-wheel steering strategy corresponding to this lap speed is saved as the new cloud-calibrated strategy;

[0033] If the current lap speed is lower than the cloud lap speed, the rear-wheel steering strategy corresponding to this lap speed will be abandoned.

[0034] A second aspect of the present application provides a rear-wheel steering calibration system that matches a racetrack scene, comprising:

[0035] The first unit is configured to determine, at least when the vehicle enters the exit circle, the type of curve and the direction of rear wheel steering based on the high-precision map, wherein the curve types include U-shaped curves and S-shaped compound curves, and the rear wheel steering directions include same-direction steering and opposite-direction steering;

[0036] a second unit, at least for calculating, when the vehicle enters a flying circle, a yaw angle and a lateral force required for the type of curve based on vehicle driving data collected by vehicle sensors;

[0037] The third unit is at least used to determine a rear wheel steering calibration strategy based on the rear wheel steering direction, the yaw angle, the lateral force and the vehicle model, and determine the rear wheel steering follow-up angle and response rate according to the rear wheel steering calibration strategy.

[0038] Optionally, the system further includes a fourth unit configured to, when the vehicle enters a flight circle, modify the rear wheel steering calibration strategy based on the vehicle entry speed and the vehicle exit speed marked on the high-precision map within the flight circle, and based on the driver's driving habits, the vehicle entry speed, and the vehicle exit speed, wherein the driver's driving habits include: the driver's reaction time and the driver's driving style;

[0039] When the driver enters the flying circle, the revised rear wheel steering calibration strategy is locked and uploaded to the cloud.

[0040] Optionally, the second unit includes a signal calculation unit, and the signal calculation unit is configured to:

[0041] Obtaining a current track model through a high-precision map, and obtaining a vehicle driving route based on the track model;

[0042] During a lap of the track based on the vehicle driving route, the vehicle's lateral acceleration signal, longitudinal acceleration signal, and yaw rate signal are obtained based on the vehicle's onboard gyroscope, a tire slip rate signal is obtained based on the wheel speed sensor, and a front and rear axle power distribution signal is obtained based on the power system;

[0043] The yaw angle and lateral force are obtained based on the lateral acceleration signal, the longitudinal acceleration signal, the yaw angular velocity signal, the tire slip ratio signal and the front and rear axle power distribution signal.

[0044] In a third aspect of the present application, an electronic device is provided, comprising: at least one processor; and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the above-mentioned rear-wheel steering calibration method based on matching track scenes.

[0045] In a fourth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computer, a rear-wheel steering calibration method based on a matching track scene is executed.

[0046] This application sets different rear-wheel steering methods for different types of tracks. High-precision maps, sensors, and vehicle models are used to obtain the yaw rate and measured speed requirements for different corners. Different rear-wheel steering strategies are matched to these requirements. In track scenarios, the rear-wheel steering method suitable for the track can be achieved without re-tuning.

[0047] In addition, by introducing cloud-based calibration strategies, historical data can be added to the rear-wheel steering strategy to achieve a better rear-wheel steering solution. It is also a shared chassis calibration strategy, which is conducive to improving the efficiency of automobile research and development and the user's experience on the track.

[0048] In addition to racetrack scenarios, this strategy can also be applied to other scenarios or paths with more bends, such as emergency rescue scenarios with complex road conditions, to reduce the calibration work of engineers and enhance the user's riding experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The following is a working principle diagram of a rear wheel same-direction steering method in the present application;

[0050] Figure 2 A diagram showing the working principle of a rear wheel counter-steering method in the present application is shown;

[0051] Figure 3 A schematic diagram of rear wheel steering in a U-turn in this application is shown;

[0052] Figure 4 A schematic diagram of rear wheel steering in an S-shaped compound bend in this application is shown;

[0053] Figure 5 A schematic diagram of the process of a rear-wheel steering calibration method matching a track scene in this application is shown;

[0054] Figure 6 A schematic diagram showing a flow chart of another rear wheel steering calibration method matching a track scene in the present application is shown;

[0055] Figure 7 A schematic diagram of the structure of a rear-wheel steering calibration system matching a racetrack scene in this application is shown;

[0056] Figure 8 A schematic diagram of vehicle hardware based on rear-wheel steering calibration in this application is shown. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0058] like Figure 1 and Figure 2 As shown in the figure, rear wheel steering (RWS) can be broadly categorized into two types: in-direction (with the front wheels) and out-direction (with the front wheels). In-direction means that when the user turns the steering wheel, the front and rear wheels simultaneously deflect to one side, generating lateral force that rapidly establishes y-axis displacement and suppresses the vehicle's yaw angle Ψ. Out-of-direction means that when the user turns the steering wheel, the front and rear wheels rotate in opposite directions. Steering geometry shows that out-of-direction rotation reduces the vehicle's turning radius, allowing the vehicle to quickly establish yaw response and complete a U-turn, but lateral displacement is suppressed.

[0059] Due to the special nature of the racetrack environment, its cornering driving conditions are relatively complex, often with a variety of different cornering conditions, and the need to operate at high speeds for a long time, which places high demands on the tire limit. The cornering conditions are listed as follows: U-shaped bends and S-shaped compound bends, such as Figure 3 and Figure 4 As shown, U-turns require rapid yaw angle establishment to achieve steering, while S-curves require rapid lateral displacement response. Furthermore, since every corner on the track is unique, with varying entry and exit speeds and tire limits, a tailored rear-wheel steering strategy is required for each corner.

[0060] See also Figure 5 A first aspect of the present invention provides a rear wheel steering calibration method matching a track scene, comprising:

[0061] Step S1: When the vehicle enters the exit circle, the curve type is determined based on the high-precision map and the direction of rear wheel steering is determined. The curve types include U-shaped curves and S-shaped compound curves. The rear wheel steering directions include same-direction steering and opposite-direction steering.

[0062] High-precision maps contain geographic information about the track and come with certain calculation capabilities. This allows the length of straight segments, the curvature and number of curves, and, through a combination of existing technologies, the type of curve. Based on different curve requirements, when a U-shaped curve, also known as a hairpin, is considered, steering in opposite directions is chosen to reduce the turning radius, allowing the vehicle to complete the turn earlier and increase exit speed. When a compound S-shaped curve is considered, steering in the same direction is chosen to improve lateral responsiveness and stability, reducing the impact of oversteering on vehicle speed.

[0063] For other curves, such as V-shaped bends, zigzag bends, L-shaped bends, etc., the direction of rear wheel steering can be selected according to the requirements for the vehicle's exit speed and the stability of the vehicle's lateral movement. If the exit speed is slow, but the responsiveness and stability of lateral movement are good, choose opposite direction steering; if the exit speed is average, but the responsiveness and stability of lateral movement need to be improved, choose the same direction steering.

[0064] Step S2: When the vehicle enters the flying circle, the yaw angle and lateral force required for the curve type are calculated based on the vehicle driving data collected by the vehicle sensors.

[0065] Specifically, the calculating of the yaw angle and lateral force required for the curve type based on the vehicle driving data collected by the vehicle sensor includes:

[0066] Obtaining a current track model through a high-precision map, and obtaining a vehicle driving route based on the track model;

[0067] During a lap of the track based on the vehicle driving route, the vehicle's lateral acceleration signal, longitudinal acceleration signal, and yaw rate signal are obtained based on the vehicle's onboard gyroscope, a tire slip rate signal is obtained based on the wheel speed sensor, and a front and rear axle power distribution signal is obtained based on the power system;

[0068] The yaw angle and lateral force are calculated based on the lateral acceleration signal, longitudinal acceleration signal, yaw rate signal, tire slip rate signal, and front and rear axle power distribution signal. Note that due to the varying curves in a racetrack scenario, the yaw angle and lateral force required for each specific curve must be calculated.

[0069] Here, yaw angle, also known as yaw rate, refers to the vehicle's deflection angle around the vertical axis. The magnitude of the yaw angle represents the vehicle's stability. Due to the centrifugal force of a tilted road or curves, lateral forces acting on the wheel centers along the y-axis are distributed. The magnitude and direction of these forces represent the vehicle's stability.

[0070] Methods for determining the yaw angle and lateral position of a vehicle using high-precision map data include:

[0071] The geometric features of the track are obtained through high-precision maps.

[0072] The optimal driving route for the vehicle is determined based on the geometric characteristics of the track. Generally speaking, the optimal driving route is fixed and can be determined based on the driving routes of previous racing cars.

[0073] Extract the driving route, decompose it into discrete point data at every 1m (the accuracy can be adjusted according to the required accuracy), and connect each point to segment the actual driving curve.

[0074] Assume that the 1m vector formed by the nth point and the n+1th point is recorded as , the yaw angle θ required by the vehicle at the nth point n for and The angle between , the required lateral displacement y at point n n for When a vehicle passes a U-shaped bend, it needs a continuous and large θ n value, and obtain the required θ for each point on the track n and y n Then the rear wheel steering angle strategy can be determined.

[0075] ,

[0076] where θ f is the front wheel angle, θ r is the rear wheel turning angle, α fis the front wheel slip angle, α r is the rear wheel slip angle, L is the vehicle wheelbase, and R is the driving radius.

[0077] The above formula describes the vehicle model with rear wheel steering. f -α f The side slip angle in the formula is related to the vehicle's design and speed, so calibration is required based on different driving conditions before the rear wheel steering angle can be determined.

[0078] It should be understood that the vehicle's built-in six-axis acceleration sensor can obtain the vehicle's lateral acceleration α that this patent focuses on. y , longitudinal acceleration α x , vehicle yaw angular acceleration α θ The vehicle's lateral displacement y, longitudinal displacement x, and yaw angle θ can be obtained through quadratic integration. These are the actual vehicle's driving data and should be used to compare the values ​​in the above model to assist in correcting the specific rear-wheel steering calibration strategy.

[0079] In addition, the two steps of the vehicle entering the flight circle and calculating the yaw angle and lateral force required for the said type of curve can be either synchronous or sequential, that is, the vehicle entering the flight circle and calculating the yaw angle and lateral force required for the said type of curve can occur simultaneously, or the yaw angle and lateral force required for the said type of curve can be calculated after the vehicle enters the flight circle.

[0080] Step S3: determining a rear wheel steering calibration strategy based on the rear wheel steering direction, the yaw angle, the lateral force and the vehicle model, and determining a rear wheel steering follow-up angle and a response rate according to the rear wheel steering calibration strategy.

[0081] This approach allows for highly accurate rear-wheel steering tracking angles and response rates for each corner, tailored to racetrack scenarios. By controlling these tracking angles and response rates, a more reasonable rear-wheel steering calibration result can be achieved. The rear-wheel steering calibration strategy, including but not limited to the tracking angles and response rates, is an output of the rear-wheel steering calibration method for racetrack scenarios.

[0082] In one embodiment of the present application, based on the high-precision map recording the vehicle entry and exit speeds in the track scene, the rear-wheel steering calibration strategy is corrected based on the driver's driving habits, the vehicle entry and exit speeds.

[0083] Specifically, when the vehicle enters a subsequent exit circle, or an exit circle where cloud data exists, the current rear-wheel steering calibration strategy can be optimized and the accuracy of the rear-wheel steering calibration strategy can be improved by consulting the cloud data and adopting a self-learning method.

[0084] Due to the unique and high-speed nature of the track, the driver's driving habits are also a key factor influencing the rear-wheel calibration strategy. These include, but are not limited to, the driver's reaction time, also known as the driver's driving sensitivity. This refers specifically to the time it takes the driver to enter the flying circle and start timing, as well as the time it takes the driver to control the steering wheel after facing a corner. These habits also include, but are not limited to, the driver's driving technique, also known as the driver's driving type. The driver's driving type takes into account factors such as the driver's driving force. Drivers' driving types can be divided into several categories through research and data collection, and each category can be divided into different categories and assigned different values. The driver's driving habits can be quantified by setting weight parameters.

[0085] When the user enters the flying circle, he can select the optimal rear-wheel steering strategy and lock it to complete the driving scene of the track.

[0086] Preferably, in order to improve the optimization control and fine-tuning of the data, the rear wheel calibration strategy and lap time during the flying lap can be uploaded to the cloud or the track scene database to improve the data utilization value.

[0087] See also Figure 6 In one embodiment of the present application, when the vehicle enters the exit circle, before determining the type of curve and the direction of rear wheel steering based on the high-precision map, the process includes:

[0088] Perform rough positioning of the vehicle based on the HD map and detect whether there is a rear-wheel steering calibration strategy on the track;

[0089] If there is no rear-wheel steering calibration strategy, the type of curve is determined based on the high-precision map and the direction of rear-wheel steering is determined.

[0090] Coarse localization, also known as simple template matching, is a common method in industrial image processing. It offers high accuracy and fast recognition time. It uses coarse localization to detect the track and determine if a rear-wheel steering calibration strategy exists on the track.

[0091] Generally speaking, the rear-wheel steering calibration strategy is stored on the vehicle side and / or in the cloud. For example, the vehicle side can store the historical rear-wheel steering strategy for the vehicle, and the cloud side stores any rear-wheel steering calibration strategy based on the corresponding track uploaded to the cloud.

[0092] If a rear-wheel steering calibration strategy exists, the cloud calibration strategy of the track is queried in the cloud, and the lap time corresponding to the cloud calibration strategy is the cloud lap time.

[0093] Specifically, querying the cloud calibration strategy of the track in the cloud, where the lap time corresponding to the cloud calibration strategy is the cloud lap time, includes:

[0094] Using the cloud-based calibration strategy, and modifying the cloud-based calibration strategy based on the driver's driving habits, the vehicle's cornering speed, and the vehicle's cornering speed;

[0095] Use the revised cloud calibration strategy to enter the flight circle and calculate the lap speed;

[0096] If the current lap time is slower than the cloud-calibrated lap time, the rear-wheel steering strategy corresponding to this lap time is saved as the new cloud-calibrated strategy;

[0097] If the current lap time is faster than the cloud lap time, the rear-wheel steering strategy corresponding to this lap time will be abandoned.

[0098] Here, through this method, the existing cloud calibration strategy can be fully utilized to make corrections and apply it to the flying lap. After completing the track driving, the lap time is recorded and compared. When the lap time is better than the cloud lap time, it means that the track driving efficiency has been improved, which is conducive to updates in the track driving scenario.

[0099] It should be understood that if a rear-wheel steering calibration strategy exists in the cloud, the rear-wheel steering calibration strategy can still be obtained based on the rear-wheel steering direction, the yaw angle, the lateral force and the whole vehicle model, and the entry and exit speeds can be marked based on the high-precision map in subsequent laps. The rear-wheel steering calibration strategy and the cloud calibration strategy can be corrected based on the driver's driving habits, the entry and exit speeds.

[0100] Compare the lap time of the drink and the cloud lap time using the revised rear-wheel steering calibration strategy and the revised cloud calibration strategy, and upload the calibration strategy representing the highest lap time to the cloud.

[0101] If there is no rear-wheel steering calibration strategy, the type of curve is determined based on the high-precision map and the direction of rear-wheel steering is determined.

[0102] Specifically, searching in the cloud whether there is a rear-wheel steering calibration strategy for the track;

[0103] If the rear-wheel steering calibration strategy for the track does not exist in the cloud, the data in the rear-wheel steering calibration strategy will be set to 0, the rear wheels will not rotate with the front wheels, and the curve type and rear-wheel steering direction will be determined based on the high-precision map.

[0104] Setting the data in the rear wheel steering to 0 and preventing the rear wheel from rotating with the front wheel can eliminate the effect of the rear wheel steering on the driver's basic lap time.

[0105] Here, through this method, effective integration can be performed both when a rear-wheel steering calibration strategy exists in the cloud and when it does not, which improves the scientific nature of applying historical data to solve existing problems and also improves the efficiency of obtaining the highest lap time.

[0106] In one embodiment of the present application, before determining the curve type and the direction of rear wheel steering based on the high-precision map, the method further includes:

[0107] The vehicle must complete at least one lap of the race to familiarize itself with the track, warm up the tires, and lubricate the shock absorber fluid.

[0108] For example, when the user drives 2-3 laps on the starting circle, he or she can familiarize himself or herself with the track and vehicle, warm up the vehicle, and adjust cloud communications to avoid unexpected situations.

[0109] See also Figure 7 In a second aspect of the present application, a rear-wheel steering calibration system matching a track scene is provided, comprising:

[0110] The first unit 21 is configured to determine, at least when the vehicle enters the exit circle, the type of curve and the direction of rear wheel steering based on the high-precision map, wherein the curve types include U-shaped curves and S-shaped compound curves, and the rear wheel steering directions include same-direction steering and opposite-direction steering;

[0111] The second unit 22 is configured to calculate the yaw angle and lateral force required for the curve type based on the vehicle driving data collected by the vehicle sensor when the vehicle enters the flying circle;

[0112] The third unit 23 is at least used to determine a rear wheel steering calibration strategy based on the rear wheel steering direction, the yaw angle, the lateral force and the vehicle model, and determine the rear wheel steering follow-up angle and response rate according to the rear wheel steering calibration strategy.

[0113] Optionally, the system further includes a fourth unit 24 configured to, when the vehicle enters a flight circle, modify the rear wheel steering calibration strategy based on the vehicle entry speed and the vehicle exit speed marked on the high-precision map within the flight circle, and based on the driver's driving habits, the vehicle entry speed, and the vehicle exit speed, wherein the driver's driving habits include: the driver's reaction time and the driver's driving style;

[0114] When the driver enters the flying circle, the revised rear wheel steering calibration strategy is locked and uploaded to the cloud.

[0115] Optionally, the second unit includes a signal calculation unit 221, the signal calculation unit being configured to: obtain a current track model through a high-precision map, and obtain a vehicle driving route based on the track model;

[0116] During a lap of the track based on the vehicle driving route, the vehicle's lateral acceleration signal, longitudinal acceleration signal, and yaw rate signal are obtained based on the vehicle's onboard gyroscope, a tire slip rate signal is obtained based on the wheel speed sensor, and a front and rear axle power distribution signal is obtained based on the power system;

[0117] The yaw angle and lateral force are obtained based on the lateral acceleration signal, the longitudinal acceleration signal, the yaw angular velocity signal, the tire slip ratio signal and the front and rear axle power distribution signal.

[0118] To better describe the rear wheel steering calibration method for matching the track mode described in this application, please refer to Figure 8 The following is a detailed description of a hardware implementation structure of the rear wheel steering calibration method described in this application, which includes a front wheel steering system 1, a rear wheel steering geometry 2, an electronic control unit 3, a steering motor 4, a high-precision Figure 5 , vehicle-cloud communication unit 6 and cloud 7. The front-wheel steering system 1 is a front-wheel steering system existing in the prior art, and the rear-wheel steering geometry 2, electronic control unit 3 and steering motor 4 constitute the rear-wheel steering system. The front-wheel steering system 1 and the rear-wheel steering system are connected in communication. The electronic control unit 4 stores the rear-wheel steering calibration system matching the track mode described in the second aspect of this application, which can control the rear-wheel steering, including the rear-wheel steering tracking angle and response rate. High-precision Figure 5 The vehicle-to-cloud communication unit 6 enables communication between the vehicle and the cloud 7 to query and download cloud calibration strategies and cloud lap times. The cloud 7 can also store and transmit rear-wheel steering calibration strategies, etc.

[0119] Through this hardware implementation structure, the logic of rear-wheel steering adjustment in a track scenario can be intuitively displayed, which is helpful for people skilled in the art to understand the internal hardware operating principles of this application.

[0120] In a third aspect of the present application, an electronic device is provided, comprising: at least one processor; and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the above-mentioned rear-wheel steering calibration method based on matching track scenes.

[0121] In a fourth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computer, a rear-wheel steering calibration method based on a matching track scene is executed.

[0122] It is understood that computer-readable storage media may include: any entity or device capable of carrying a computer program, recording media, USB flash drives, mobile hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), and software distribution media, etc. A computer program includes computer program code. The computer program code may be in source code form, object code form, an executable file, or some intermediate form, etc. Computer-readable storage media may include: any entity or device capable of carrying a computer program code, recording media, USB flash drives, mobile hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), and software distribution media, etc.

[0123] In certain embodiments of the present invention, the device may include a controller, which is a single-chip microcomputer chip that integrates a processor, memory, a communication module, etc. The processor may refer to the processor contained in the controller. The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0124] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0125] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the composition and steps of each example according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0126] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A rear wheel steering calibration method matching a racetrack scene, characterized in that: include: When the vehicle enters the exit circle, the curve type is determined based on the high-precision map and the direction of rear wheel steering is determined. The curve types include U-shaped curves and S-shaped compound curves. The rear wheel steering directions include same-direction steering and opposite-direction steering. When the vehicle enters the flight circle, the yaw angle and lateral force required for the type of curve are calculated based on vehicle driving data collected by vehicle sensors; determining a rear wheel steering calibration strategy based on the rear wheel steering direction, the yaw angle, the lateral force, and a vehicle model, and determining a rear wheel steering follow-up angle and a response rate according to the rear wheel steering calibration strategy; Based on marking the vehicle entering and exiting a corner on the high-precision map, the rear-wheel steering calibration strategy is corrected based on the driver's driving habits, the vehicle entering and exiting a corner, and the driver's driving habits including the driver's reaction time and the driver's driving type.

2. The rear wheel steering calibration method according to claim 1, characterized in that: Also includes: When the driver enters the flying circle, the revised rear wheel steering calibration strategy is locked and uploaded to the cloud.

3. The rear wheel steering calibration method according to claim 1, characterized in that: The calculating the yaw angle and lateral force required for the curve type based on the vehicle driving data collected by the vehicle sensor includes: Obtaining a current track model through a high-precision map, and obtaining a vehicle driving route based on the track model; During a lap of the track based on the vehicle driving route, the vehicle's lateral acceleration signal, longitudinal acceleration signal, and yaw rate signal are obtained based on the vehicle's onboard gyroscope, a tire slip rate signal is obtained based on the wheel speed sensor, and a front and rear axle power distribution signal is obtained based on the power system; The yaw angle and lateral force are obtained based on the lateral acceleration signal, the longitudinal acceleration signal, the yaw angular velocity signal, the tire slip ratio signal and the front and rear axle power distribution signal.

4. The rear wheel steering calibration method according to claim 1, wherein: When the vehicle enters the exit circle, before determining the type of curve and the direction of rear wheel steering based on the high-precision map, the following steps are included: Perform rough positioning of the vehicle based on the HD map and detect whether there is a rear-wheel steering calibration strategy on the track; If there is no rear-wheel steering calibration strategy, the type of curve is determined based on the high-precision map and the direction of rear-wheel steering is determined.

5. The rear wheel steering calibration method according to claim 4, characterized in that: Before judging the curve type and determining the direction of rear wheel steering based on the high-precision map, the method further includes: The vehicle must complete at least one lap of the race to familiarize itself with the track, warm up the tires, and lubricate the shock absorber fluid.

6. The rear wheel steering calibration method according to claim 5, characterized in that: The strategy for roughly positioning the vehicle based on the HD map and detecting whether there is rear-wheel steering on the track includes: Determine the track the vehicle is on based on the rough positioning, and search the cloud for a rear-wheel steering calibration strategy for the track. If the rear wheel steering calibration strategy for the track does not exist in the cloud, the data in the rear wheel steering calibration strategy is set to 0, and the rear wheels do not rotate with the front wheels.

7. The rear wheel steering calibration method according to claim 5, characterized in that: Searching the cloud for a rear-wheel steering calibration strategy for the track also includes: The cloud calibration strategy of the track is queried in the cloud, and the cloud calibration strategy is modified when the vehicle enters the flight circle.

8. The rear wheel steering calibration method according to claim 7, characterized in that: The querying of the cloud calibration strategy of the track in the cloud and modifying the cloud calibration strategy when the vehicle enters the flight circle includes: Using the cloud-based calibration strategy, and modifying the cloud-based calibration strategy based on the driver's driving habits, cornering speed, and cornering exit speed; Use the revised cloud calibration strategy to enter the flight circle and calculate the lap speed; If the current lap speed is higher than the cloud-calibrated lap speed, the rear-wheel steering strategy corresponding to this lap speed is saved as the new cloud-calibrated strategy; If the current lap speed is lower than the cloud lap speed, the rear-wheel steering strategy corresponding to this lap speed will be abandoned.

9. A rear-wheel steering calibration system matching a racetrack scene, characterized in that: include: The first unit is configured to determine, at least when the vehicle enters the exit circle, the type of curve and the direction of rear wheel steering based on the high-precision map, wherein the curve types include U-shaped curves and S-shaped compound curves, and the rear wheel steering directions include same-direction steering and opposite-direction steering; a second unit, at least for calculating, when the vehicle enters a flying circle, a yaw angle and a lateral force required for the type of curve based on vehicle driving data collected by vehicle sensors; a third unit, configured to determine a rear wheel steering calibration strategy based on the rear wheel steering direction, the yaw angle, the lateral force, and a vehicle model, and determine a rear wheel steering follow-up angle and a response rate according to the rear wheel steering calibration strategy; The fourth unit is used at least for correcting the rear-wheel steering calibration strategy based on the vehicle entry speed and exit speed marked on the high-precision map within the flight circle when the vehicle enters the flight circle, and based on the driver's driving habits, the vehicle entry speed and the exit speed, wherein the driver's driving habits include the driver's reaction time and the driver's driving type.

10. The rear wheel steering calibration system according to claim 9, characterized in that: The fourth unit also includes locking the revised rear wheel steering calibration strategy after the driver enters the flying circle, and uploading the revised rear wheel steering calibration strategy to the cloud.

11. The rear wheel steering calibration system according to claim 9, characterized in that: The second unit includes a signal calculation unit, which is configured to: Obtaining a current track model through a high-precision map, and obtaining a vehicle driving route based on the track model; During a lap of the track based on the vehicle driving route, the vehicle's lateral acceleration signal, longitudinal acceleration signal, and yaw rate signal are obtained based on the vehicle's onboard gyroscope, a tire slip rate signal is obtained based on the wheel speed sensor, and a front and rear axle power distribution signal is obtained based on the power system; The yaw angle and lateral force are obtained based on the lateral acceleration signal, the longitudinal acceleration signal, the yaw angular velocity signal, the tire slip ratio signal and the front and rear axle power distribution signal.

12. An electronic device, characterized in that: include: at least one processor; and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the method according to any one of claims 1 to 8.

13. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed by a computer, the method according to any one of claims 1 to 8 is executed.

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