A steering angle calibration method, a feedback system thereof and a vehicle

Abstract

This invention provides a steering angle calibration method, its feedback system, and a vehicle, relating to the field of autonomous driving control technology. The steering angle calibration method involves calibrating steering points on the vehicle's steering mechanism, constructing a steering model, performing simulation based on the steering model, and generating a simulated curve corresponding to the wheel steering angle and the steering cylinder stroke. By repeatedly constructing the steering model, the accuracy of the feedback angle is ensured. This method can be used for angle feedback during steering in autonomous vehicles. By constructing a simulation model, the relationship curve between the steering cylinder stroke and the front wheel steering angle can be quickly established, eliminating the need for repeated manual measurements, thus ensuring work efficiency. Furthermore, by comparing the differences, the accuracy of the curve used for feedback by the steering angle feedback system is effectively guaranteed, ensuring accurate steering of the vehicle during autonomous driving.

Description

Technical Field

[0001] This invention relates to the field of unmanned driving control technology, and more specifically, to a steering angle calibration method, its feedback system, and a vehicle. Background Technology

[0002] With the development of science and technology, unmanned driving control has been widely applied. For example, existing mining dump trucks and other engineering vehicles have achieved automated operation in engineering production processes through unmanned driving control technology.

[0003] In the use of autonomous vehicles, the accuracy of vehicle steering is crucial to the normal operation of the vehicle. For the steering control of autonomous vehicles, the stroke of the vehicle's steering cylinder is generally collected. The front wheel steering angle is fed back by the collected steering cylinder stroke to complete the vehicle's steering control. Therefore, it is necessary to obtain the correspondence between the steering cylinder stroke and the front wheel steering angle to calibrate the front wheel steering angle.

[0004] Currently, the calibration of front wheel steering angle is generally achieved by controlling the front wheel steering angle by turning the steering wheel. The specific steering angle of the front wheels is obtained by marking and measuring at different steering angles. This specific steering angle is then correlated with the specific stroke of the steering cylinder. Through repeated measurements, the relationship between the steering cylinder stroke and the front wheel steering angle is calibrated, resulting in a curve showing the relationship between the two. However, this marking and measurement method requires repeated measurements and calibrations at multiple angles, which is labor-intensive. Furthermore, manual marking and measurement has a large measurement error, resulting in a low accuracy of the obtained curve, which is detrimental to accurate steering of vehicles during autonomous driving. Summary of the Invention

[0005] The problem addressed by this invention is how to improve the accuracy of the relationship curve between the stroke of the steering cylinder and the steering angle of the front wheels in autonomous vehicles, so as to ensure accurate steering of the vehicle during autonomous driving.

[0006] To address the above problems, this invention provides a steering angle calibration method applied to vehicles. The steering angle calibration method includes the following steps:

[0007] The steering points of the vehicle's steering mechanism are calibrated, and a steering model is established based on the steering points.

[0008] The steering model is used to perform a simulation to obtain the simulation correspondence curve between the stroke of the steering cylinder of the steering mechanism and the steering angle of the vehicle's wheels, and the simulation correspondence curve is input into the vehicle's steering angle feedback system.

[0009] The steering cylinder controls the rotation of the wheel, and the steering angle feedback system collects the actual stroke of the steering cylinder and obtains the actual steering angle of the wheel.

[0010] Based on the actual stroke of the steering cylinder and the corresponding simulation curve, the steering angle is output through the steering angle feedback system.

[0011] The difference between the actual steering angle and the feedback steering angle is calculated, and it is determined whether the difference is within a preset error range.

[0012] If not, recalibrate the steering point and repeat the above steps; if yes, the calibration of the steering angle feedback system is complete.

[0013] Compared to existing technologies, the beneficial effects of the steering angle calibration method of the present invention include: calibrating steering points on the vehicle's steering mechanism, constructing a steering model, performing simulation based on the steering model, generating a simulation correspondence curve between the wheel steering angle and the steering cylinder stroke, inputting the simulation curve into the wheel steering angle feedback system, which can substitute the actual stroke of the vehicle's steering cylinder into the simulation correspondence curve to obtain the corresponding feedback steering angle, and calculating the difference between the feedback steering angle and the actual wheel steering angle. If the difference is outside a preset error range, it indicates that the feedback steering angle output by the steering angle feedback system is not correct. Since the angle has not yet reached the required accuracy, the steering point can be recalibrated. The construction of the steering model and the comparison and judgment of the feedback steering angle can be repeated until the difference is within the preset error range. At this point, it can be determined that the calibration of the steering angle feedback system is complete and can be used for angle feedback when the autonomous vehicle is turning. In this way, the relationship curve between the steering cylinder stroke and the front wheel steering angle can be quickly established by constructing a simulation model, without the need for repeated manual measurements, thus ensuring work efficiency. Furthermore, the accuracy of the curve used for feedback by the steering angle feedback system can be effectively ensured by the difference comparison, thus ensuring accurate steering of the vehicle during autonomous driving.

[0014] Optionally, calibrating the steering point of the vehicle's steering mechanism includes:

[0015] Obtain the rotation center of the steering mechanism, which includes the center of the steering knuckle arm, the tie rod joint bearing, the rod-side joint bearing of the steering cylinder, and the rodless joint bearing of the steering cylinder.

[0016] When the wheel is fully straightened, the center of rotation is marked as the steering point.

[0017] Optionally, establishing a steering model based on the steering point includes:

[0018] Based on the calibrated turning points, obtain the relative distance between each turning point;

[0019] Based on the relative distance and coordinate system, determine the coordinates of the turning point;

[0020] Obtain the installation distance of the steering cylinder, the installation distance including the mid-position installation distance, the maximum installation distance, and the minimum installation distance;

[0021] The stroke of the steering cylinder when the wheel turns is obtained based on the installation distance;

[0022] The steering model is constructed based on the motion travel and the coordinates.

[0023] Optionally, the steering cylinder includes a left steering cylinder and a right steering cylinder, and the rotation center includes a left rotation center and / or a right rotation center. The left rotation center includes the center of the left steering knuckle arm, the left joint bearing of the tie rod, the rod-side joint bearing of the left steering cylinder, and the rodless joint bearing of the left steering cylinder. The right rotation center includes the center of the right steering knuckle arm, the right joint bearing of the tie rod, the rod-side joint bearing of the right steering cylinder, and the rodless joint bearing of the right steering cylinder.

[0024] Optionally, the steering angle feedback system includes a linear displacement sensor, one end of which is mounted on the cylinder of the steering cylinder, and the other end of which is mounted on the piston rod of the steering cylinder.

[0025] Optionally, there are two linear displacement sensors, and the steering cylinder includes a left steering cylinder and a right steering cylinder, with the two linear displacement sensors respectively mounted on the left steering cylinder and the right steering cylinder.

[0026] Optionally, the steering angle feedback system further includes a drive-by-wire module, which is electrically connected to the linear displacement sensor. The drive-by-wire module is used to acquire the actual stroke of the steering cylinder and input the corresponding simulation curve, and output the feedback steering angle.

[0027] Optionally, obtaining the actual steering angle of the wheel includes: obtaining the actual steering angle corresponding to the actual travel obtained by the scribing measurement method, and inputting the actual steering angle into the steering angle feedback system.

[0028] On the other hand, the present invention also provides a steering angle feedback system, including a linear displacement sensor, a processor, and a memory, wherein the memory is used to store instructions for controlling the processor to operate in order to execute the steering angle calibration method as described above.

[0029] Compared to the prior art, the beneficial effects of the steering angle feedback system of the present invention are the same as those of the steering angle calibration method described above, and will not be repeated here.

[0030] In another aspect, the present invention also provides a vehicle including wheels, a steering mechanism and a steering angle feedback system as described above.

[0031] Compared to the prior art, the beneficial effects of the vehicle of the present invention are the same as those of the steering angle feedback system described above, and will not be repeated here. Attached Figure Description

[0032] Figure 1 This is a flowchart of the steering angle calibration method in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the steering mechanism in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram illustrating how the steering mechanism drives the wheels to rotate in one direction, according to an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram illustrating how the steering mechanism drives the wheel to rotate in another direction in an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the installation of a linear displacement sensor on a steering cylinder in an embodiment of the present invention;

[0037] Figure 6 This is a simulation curve showing the correspondence between the wheel steering angle and the stroke of a steering cylinder in an embodiment of the present invention.

[0038] Figure 7 This is a simulation curve showing the correspondence between the wheel steering angle and the stroke of another steering cylinder in an embodiment of the present invention.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1- Center of left steering knuckle arm; 2- Left tie rod joint bearing; 3- Rod-side joint bearing of left steering cylinder; 4- Rodless joint bearing of left steering cylinder; 5- Center of right steering knuckle arm; 6- Right tie rod joint bearing; 7- Rod-side joint bearing of right steering cylinder; 8- Rodless joint bearing of right steering cylinder; 9- Linear displacement sensor. Detailed Implementation

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] On one hand, one embodiment of the present invention provides a steering angle calibration method applied to a vehicle. The steering angle calibration method includes the following steps: calibrating the steering point of the vehicle's steering mechanism and establishing a steering model based on the steering point; performing simulation based on the steering model to obtain the simulation correspondence curve between the stroke of the steering cylinder of the steering mechanism and the steering angle of the vehicle's wheels, and inputting the simulation correspondence curve into the vehicle's steering angle feedback system; controlling the wheel rotation through the steering cylinder, collecting the actual stroke of the steering cylinder through the steering angle feedback system, and simultaneously obtaining the actual steering angle of the wheel; outputting a feedback steering angle through the steering angle feedback system based on the actual stroke of the steering cylinder and the simulation correspondence curve; subtracting the actual steering angle from the feedback steering angle and determining whether the difference is within a preset error range; if not, recalibrating the steering point and repeating the above steps; if yes, the calibration of the steering angle feedback system is completed.

[0043] In this embodiment, as Figure 1 As shown in step S1, steering points are marked on the vehicle's steering mechanism. These steering points move as the wheels steer when the steering mechanism drives them. By selecting a certain number of steering points, a steering model is constructed. Based on this model, the movement of the entire steering mechanism when the wheels steer can be simulated. Figure 1 As shown in step S2, when the wheel is steered using the established steering model, the steering mechanism undergoes a simulation of its movement. When the wheel is steered to a certain angle, the stroke of the steering cylinder in the steering mechanism also changes accordingly. This simulation generates a curve showing the correspondence between the wheel steering angle and the steering cylinder stroke, which can then be input into the wheel steering angle feedback system. Figure 1 As shown in steps S3 to S6, the steering angle feedback system can substitute the actual stroke of the vehicle's steering cylinder into the corresponding simulation curve to obtain the corresponding feedback steering angle in the simulation curve. At the same time, the steering angle feedback system can obtain the actual steering angle of the wheel, and thus the difference between the feedback steering angle and the actual steering angle can be calculated. If the difference is outside the preset error range, it means that the feedback steering angle output by the steering angle feedback system has not yet reached the required accuracy. Therefore, the steering point can be recalibrated, and the construction of the steering model and the comparison and judgment of the feedback steering angle can be repeated until the difference is within the preset error range. At this point, it can be determined that the calibration of the steering angle feedback system has been completed and can be used for angle feedback when the autonomous vehicle is turning. Thus, by constructing a simulation model, the relationship curve between the steering cylinder stroke and the front wheel steering angle can be quickly established without the need for repeated manual measurements, ensuring work efficiency. The difference comparison effectively ensures the accuracy of the curve used for feedback by the steering angle feedback system, ensuring accurate steering of the vehicle during autonomous driving.

[0044] It should be noted that when using the steering angle feedback system of this invention and the obtained simulation curve to steer an autonomous vehicle, the autonomous driving system issues a target steering angle command, the steering angle feedback system outputs a feedback steering angle, and the autonomous driving system compares the target steering angle with the feedback steering angle. If the feedback steering angle does not reach the target steering angle, the system continues to control the wheel steering. Through multiple small-angle steering controls and the real-time output of the steering angle feedback system, the system achieves the goal of accurate control of the vehicle steering.

[0045] It should be noted that in this embodiment, when there is no three-dimensional model or two-dimensional drawing of the steering mechanism, the calibration point can be obtained by moving the steering mechanism to its limit position and using a plumb bob for positioning. Of course, when there is a three-dimensional model or two-dimensional drawing of the steering mechanism, the calibration point can be directly calibrated according to the three-dimensional model and two-dimensional drawing.

[0046] It should be noted that in this embodiment, the actual steering angle of the wheel can be obtained by the scribing measurement method in order to determine whether the feedback steering angle output by the angle feedback system is accurate. Of course, in other embodiments of the present invention, the actual steering angle of the wheel can also be obtained by other methods or instruments.

[0047] It should be noted that, in this embodiment, the angle feedback system includes a control subsystem and a sensing subsystem electrically connected to each other. The sensing subsystem is used to acquire the actual stroke of the steering cylinder when the wheel turns and transmit it to the control subsystem. The control subsystem is used to pre-store the simulation curve and output the feedback steering angle based on the simulation curve and the input actual stroke of the steering cylinder. Specifically, the control subsystem is a drive-by-wire module, and the simulation curve is input into the drive-by-wire module through programming, such as... Figure 5 As shown, the sensing subsystem is a linear displacement sensor 9 installed on the steering cylinder. Therefore, the linear displacement sensor 9 can be directly installed on the outside of the steering cylinder, so that the angle feedback system of the present invention can also be applied to the modification of vehicle autonomous driving control.

[0048] It should be noted that before the steering model outputs the corresponding simulation curve, the steering model obtains multiple straight lines through multiple steering simulations, such as... Figure 6 and Figure 7 As shown, the simulation curves are fitted using a multi-point approximation method, resulting in the final simulation curves for the steering cylinder and wheel angles. Alternatively, the final simulation curves can also be obtained through function calculations.

[0049] It should be noted that in this embodiment, ADAMS (Automatic Dynamic Analysis of Mechanical Systems) software is used to construct the steering model and simulate wheel steering. In other embodiments of the present invention, other dynamic simulation software may also be used for simulation.

[0050] Optionally, calibrating the steering point of the vehicle's steering mechanism includes: obtaining the rotation center of the steering mechanism, which includes the steering knuckle arm center, the tie rod spherical bearing, the rod end spherical bearing of the steering cylinder, and the rodless end spherical bearing of the steering cylinder; and calibrating the rotation center as the steering point when the wheels are fully returned to center.

[0051] In this embodiment, to ensure the accuracy of the simulation of the constructed steering model, the rotation center of the steering mechanism is calibrated as the steering point when the wheels are fully returned to center. The steering simulation is performed using the constructed steering model based on the change in the position of the rotation center during steering mechanism operation. Specifically, the rotation center serving as the steering point includes the steering knuckle arm center, the tie rod joint bearing, the rod-side joint bearing of the steering cylinder, and the rodless joint bearing of the steering cylinder.

[0052] It should be noted that, of course, in other embodiments of the present invention, the steering point can also be marked at other locations of the steering mechanism, such as the middle of the steering knuckle arm or the middle section of the tie rod.

[0053] Optionally, establishing a steering model based on steering points includes: obtaining the relative distance between each steering point based on the calibrated steering points; calibrating the coordinates of the steering points based on the relative distances and the coordinate system; obtaining the installation distance of the steering cylinder, including the center installation distance, the maximum installation distance, and the minimum installation distance; obtaining the stroke of the steering cylinder when the wheel is turning based on the installation distance; and constructing a steering model based on the stroke and coordinates.

[0054] In this embodiment, when constructing the steering model using calibrated steering points, the specific steps are as follows: First, based on the calibrated steering points, the relative distances between each steering point are obtained. Then, based on the relative distances and the coordinate system, the specific coordinates of each steering point are obtained, and a static steering model is constructed. Next, after the specific action of the steering cylinder is completed, or based on the three-dimensional model and two-dimensional drawings, the installation distance of the steering cylinder, namely the center installation distance, maximum installation distance, and minimum installation distance of the steering cylinder, can be obtained. Thus, based on the installation distance of the steering cylinder, the stroke of the steering cylinder when the wheel is turning is obtained. Finally, based on the stroke and the specific coordinates of the steering points, a dynamic steering model is constructed.

[0055] Optionally, the steering cylinder includes a left steering cylinder and a right steering cylinder, and the rotation center includes a left rotation center and / or a right rotation center. The left rotation center includes a left steering knuckle arm center 1, a left tie rod joint bearing 2, a rod-side joint bearing 3 of the left steering cylinder, and a rodless joint bearing 4 of the left steering cylinder. The right rotation center includes a right steering knuckle arm center 5, a right tie rod joint bearing 6, a rod-side joint bearing 7 of the right steering cylinder, and a rodless joint bearing 8 of the right steering cylinder.

[0056] In this embodiment, as Figure 2 As shown, the steering mechanism of the front wheels of the vehicle is equipped with a left steering cylinder and a right steering cylinder. When obtaining the rotation center of the steering cylinder, the corresponding rotation center also includes the left rotation center and the right rotation center. When constructing the steering model, the steering point can be calibrated only on the left steering cylinder or the right steering cylinder, or the steering point can be calibrated on both steering cylinders. Of course, the left rotation center includes the left steering knuckle arm center 1, the left tie rod joint bearing 2, the left steering cylinder rod chamber joint bearing 3, and the left steering cylinder rodless chamber joint bearing 4. The right rotation center includes the right steering knuckle arm center 5, the right tie rod joint bearing 6, the right steering cylinder rod chamber joint bearing 7, and the right steering cylinder rodless chamber joint bearing 8.

[0057] It should be noted that, as Figure 6 and Figure 7 As shown, the simulation curves obtained through the steering model show that the stroke of each steering cylinder corresponds to the steering angle of the two front wheels. This means that by obtaining the stroke of only one steering cylinder, the steering angles of the two front wheels can be output, ensuring the stability of autonomous driving control. Therefore, in this embodiment, steering points are calibrated on both steering cylinders. This ensures the accuracy of the steering model during simulation and facilitates the output of the corresponding curves of the strokes of both steering cylinders and the steering angles of the two wheels. This allows the steering angles of both wheels to be obtained by acquiring the stroke of only one steering cylinder.

[0058] Optionally, the steering angle feedback system includes a linear displacement sensor 9, one end of which is mounted on the cylinder of the steering cylinder, and the other end of which is mounted on the piston rod of the steering cylinder.

[0059] In this embodiment, as Figure 5 As shown, a linear displacement sensor 9 is installed on the steering cylinder. Specifically, the two ends of the linear displacement sensor 9 are connected to the cylinder barrel and the piston rod of the steering cylinder, respectively, so as to obtain the moving distance of the piston rod when the piston rod moves, thereby obtaining the stroke of the steering cylinder.

[0060] It should be noted that, since the linear displacement sensor 9 can be directly installed on the outside of the steering cylinder, the angle feedback system of the present invention can also be applied to the modification of vehicle autonomous driving control.

[0061] Optionally, there are two linear displacement sensors 9, and the steering cylinder includes a left steering cylinder and a right steering cylinder, with the two linear displacement sensors 9 respectively mounted on the left steering cylinder and the right steering cylinder.

[0062] In this embodiment, to avoid the situation where the entire autonomous driving control system becomes unusable if a single linear displacement sensor 9 malfunctions, two linear displacement sensors 9 are installed, respectively on the left and right steering cylinders. Figure 6 and Figure 7 As shown in the simulation curve obtained through the steering model, the stroke of each steering cylinder corresponds to the steering angle of the two front wheels. This means that by obtaining the stroke of only one steering cylinder, the steering angle of the two front wheels can be output, thus ensuring the stability of the autonomous driving control.

[0063] Optionally, the steering angle feedback system also includes a drive-by-wire module, which is electrically connected to the linear displacement sensor 9. The drive-by-wire module is used to acquire the actual stroke of the steering cylinder and the corresponding curve of the input simulation, and output the feedback steering angle.

[0064] In this embodiment, the steering angle feedback system is also equipped with a drive-by-wire module electrically connected to the linear displacement sensor 9. The drive-by-wire module can obtain the actual stroke of the steering cylinder through external input, or it can obtain the programmed simulation curve. Based on the actual stroke of the steering cylinder and the simulation curve, the feedback steering angle can be obtained and output in real time.

[0065] Optionally, obtaining the actual steering angle of the wheel includes: obtaining the actual steering angle corresponding to the actual travel obtained by the scribing measurement method, and inputting the actual steering angle into the steering angle feedback system.

[0066] In this embodiment, the actual steering angle of the wheel can be obtained by scribing measurement and then input into the steering angle feedback system. Of course, in other embodiments of the present invention, the actual steering angle of the wheel can also be obtained by other methods or instruments. The measuring instrument can also be electrically connected to the steering angle feedback system to realize the rapid measurement and transmission of the actual steering angle.

[0067] On the other hand, one embodiment of the present invention provides a steering angle feedback system, including a linear displacement sensor 9, a processor, and a memory, wherein the memory is used to store instructions for controlling the processor to perform the above-described steering angle calibration method.

[0068] like Figures 1 to 5 As shown, the technical effect of the steering angle feedback system in this embodiment is similar to that of the steering angle calibration method described above, and will not be repeated here.

[0069] In another aspect, one embodiment of the present invention provides a vehicle including wheels, a steering mechanism, and the aforementioned steering angle feedback system.

[0070] like Figures 1 to 5 As shown, the technical effect of the vehicle in this embodiment is similar to that of the steering angle feedback system described above, and will not be repeated here.

[0071] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for calibrating steering angle, characterized in that, When applied to vehicles, the steering angle calibration method includes the following steps: The steering points of the vehicle's steering mechanism are calibrated, and a steering model is established based on the steering points. The steering model is used to perform a simulation to obtain the simulation correspondence curve between the stroke of the steering cylinder of the steering mechanism and the steering angle of the vehicle's wheels, and the simulation correspondence curve is input into the vehicle's steering angle feedback system. The steering cylinder controls the rotation of the wheel, and the steering angle feedback system collects the actual stroke of the steering cylinder and obtains the actual steering angle of the wheel. Based on the actual stroke of the steering cylinder and the corresponding simulation curve, the steering angle is output through the steering angle feedback system. The difference between the actual steering angle and the feedback steering angle is calculated, and it is determined whether the difference is within a preset error range. If not, recalibrate the steering point and repeat the above steps; if yes, the calibration of the steering angle feedback system is complete. The steering point positions of the vehicle's steering mechanism are defined as follows: Obtain the rotation center of the steering mechanism, which includes the center of the steering knuckle arm, the tie rod joint bearing, the rod-side joint bearing of the steering cylinder, and the rodless joint bearing of the steering cylinder. When the wheel is fully straightened, the center of rotation is marked as the steering point.

2. The steering angle calibration method according to claim 1, characterized in that, The step of establishing a steering model based on the steering point includes: Based on the calibrated turning points, obtain the relative distance between each turning point; Based on the relative distance and coordinate system, determine the coordinates of the turning point; Obtain the installation distance of the steering cylinder, the installation distance including the mid-position installation distance, the maximum installation distance, and the minimum installation distance; The stroke of the steering cylinder when the wheel turns is obtained based on the installation distance; The steering model is constructed based on the motion travel and the coordinates.

3. The steering angle calibration method according to claim 1, characterized in that, The steering cylinder includes a left steering cylinder and a right steering cylinder. The rotation center includes a left rotation center and / or a right rotation center. The left rotation center includes the center of the left steering knuckle arm (1), the left joint bearing of the tie rod (2), the rod-side joint bearing of the left steering cylinder (3), and the rodless joint bearing of the left steering cylinder (4). The right rotation center includes the center of the right steering knuckle arm (5), the right joint bearing of the tie rod (6), the rod-side joint bearing of the right steering cylinder (7), and the rodless joint bearing of the right steering cylinder (8).

4. The steering angle calibration method according to claim 1, characterized in that, The steering angle feedback system includes a linear displacement sensor (9), one end of which is mounted on the cylinder of the steering cylinder, and the other end of which is mounted on the piston rod of the steering cylinder.

5. The steering angle calibration method according to claim 4, characterized in that, There are two linear displacement sensors (9), and the steering cylinder includes a left steering cylinder and a right steering cylinder. The two linear displacement sensors (9) are respectively installed on the left steering cylinder and the right steering cylinder.

6. The steering angle calibration method according to claim 4, characterized in that, The steering angle feedback system also includes a drive-by-wire module, which is electrically connected to the linear displacement sensor (9). The drive-by-wire module is used to obtain the actual stroke of the steering cylinder and input the corresponding simulation curve, and output the feedback steering angle.

7. The steering angle calibration method according to claim 1, characterized in that, The step of obtaining the actual steering angle of the wheel includes: obtaining the actual steering angle corresponding to the actual travel obtained by the scribing measurement method, and inputting the actual steering angle into the steering angle feedback system.

8. A steering angle feedback system, characterized in that, It includes a linear displacement sensor (9), a processor, and a memory, wherein the memory is used to store instructions for controlling the processor to operate in order to perform the steering angle calibration method according to any one of claims 1 to 7.

9. A vehicle, characterized in that, It includes wheels, a steering mechanism, and a steering angle feedback system as described in claim 8.

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