A method and terminal for tracking control of a front-wheel-steering reverse unmanned vehicle

Abstract

The application discloses a kind of unmanned front wheel steering reverse tracking control method and terminal, and real-time vehicle positioning point coordinates are obtained by satellite positioning, and the positioning point offset value in the middle of front steering wheel is offset to tail part by positioning point offset algorithm, and offset positioning point coordinates are obtained;According to the offset positioning point coordinates and target tracking positioning point coordinates, the steering angle is calculated;According to the steering angle matching calculation steering angle, the steering wheel is controlled;The application offsets satellite positioning point coordinates when tracking reverse, and subsequent control calculation is carried out based on the offset positioning point coordinates after offset calculation, avoids the problem that vehicle positioning point is set in the middle of steering wheel, resulting in positioning lag, and inaccurate reverse tracking driving.

Description

Technical Field

[0001] This invention relates to the field of unmanned technology, and in particular to a tracking control method and terminal for unmanned front-wheel steering reversing. Background Technology

[0002] Autonomous driving is a current technological trend, especially in certain specialized fields where it is essential for successful implementation. Forward tracking, controlled by the front steering wheels, is relatively easier. Setting the vehicle's positioning point at the center of the steering wheels allows for direct response to changes in the vehicle's position and direction, enabling rapid adjustments and forward tracking. However, achieving reverse tracking while maintaining the same hardware is more challenging. When the vehicle's positioning point is at the center of the steering wheels, directly using positioning data for reverse tracking results in a lag, causing the rear of the vehicle to deviate from the trajectory until the front of the vehicle approaches the track. This process of readjusting the steering then causes the rear of the vehicle to deviate again, resulting in repeated turns and a serpentine path. Achieving more accurate reverse tracking is the technical problem this invention aims to solve. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a tracking control method and terminal for unmanned front-wheel steering reversing, so as to improve the accuracy of reversing tracking driving.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A tracking control method for an unmanned front-wheel steering reversing vehicle includes the following steps:

[0006] S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates.

[0007] S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking positioning point;

[0008] S3. Calculate the steering wheel angle based on the steering angle and control the steering wheel.

[0009] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows:

[0010] An unmanned front-wheel steering reversing tracking control terminal includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps:

[0011] S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates.

[0012] S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking positioning point;

[0013] S3. Calculate the steering wheel angle based on the steering angle and control the steering wheel.

[0014] The beneficial effects of the present invention are as follows: The unmanned front-wheel steering reversing tracking control terminal of the present invention performs offset calculation on the coordinates of the satellite positioning point during tracking reversing, and performs subsequent control calculations based on the offset positioning point coordinates after offset calculation, thereby avoiding the problem of positioning lag and inaccurate reversing tracking driving caused by the vehicle positioning point being set in the middle of the steering wheel. Attached Figure Description

[0015] Figure 1 A flowchart of a tracking control method for an unmanned front-wheel steering reversing vehicle according to an embodiment of the present invention;

[0016] Figure 2 This is a structural diagram of a tracking control terminal for an unmanned front-wheel steering reversing vehicle according to an embodiment of the present invention;

[0017] Figure 3 This is an example diagram illustrating the relationship between the first limiting distance and the driving speed in a tracking control method for unmanned front-wheel steering reversing according to an embodiment of the present invention.

[0018] Figure 4 This is an example diagram showing the comparison between the latitude and longitude coordinate system and the vehicle coordinate system of a tracking control method for front-wheel steering reversing in an unmanned vehicle according to an embodiment of the present invention.

[0019] Label Explanation:

[0020] 1. A tracking control terminal for unmanned front-wheel steering reversing; 2. Processor; 3. Memory. Detailed Implementation

[0021] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0022] Please refer to Figure 1 A tracking control method for front-wheel steering reverse driving of an unmanned vehicle, comprising the following steps:

[0023] S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates.

[0024] S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking positioning point;

[0025] S3. Calculate the steering wheel angle based on the steering angle and control the steering wheel.

[0026] As can be seen from the above description, the beneficial effects of the present invention are as follows: The unmanned front-wheel steering reversing tracking control terminal of the present invention performs offset calculation on the coordinates of the satellite positioning point during reversing and performs subsequent control calculations based on the offset positioning point coordinates after offset calculation, thereby avoiding the problem of positioning lag and inaccurate reversing tracking driving caused by the vehicle positioning point being set in the middle of the steering wheel.

[0027] Furthermore, the positioning point offset algorithm is specifically as follows:

[0028] Longitude_offset=Longitude+sin(direction_angle_offset)*car_len;

[0029] Latitude_offset=Latitude+cos(direction_angle_offset)*car_len;

[0030]

[0031] Wherein, direction_angle_offset represents the offset direction angle, direction_angle represents the original direction angle, the original direction angle is the angle formed by rotating clockwise from due north in the latitude and longitude coordinate system, Longitude_offset represents the longitude after offset, Longitude represents the original longitude, car_len represents the length of the car body, Latitude_offset represents the latitude after offset, and Latitude represents the original latitude.

[0032] As can be seen from the above description, the offset of the positioning point can be calculated using the above formula.

[0033] Further, step S2 includes the following steps:

[0034] S21. Based on the offset positioning point coordinates obtained in real time, calculate the vehicle's reversing direction and establish a latitude and longitude coordinate system, which includes the target tracking point coordinates.

[0035] S22. Based on the offset direction angle, the latitude and longitude coordinate system is transformed to obtain the vehicle body coordinate system, and the required steering angle of the vehicle is calculated based on the vehicle body coordinate system.

[0036] As described above, based on the offset positioning point coordinates obtained from the offset calculation, a latitude and longitude coordinate system is established. By transforming the vehicle body coordinate system and the offset direction angle model coordinate system, the target tracking point is converted and fixed in the vehicle body coordinate system, thereby determining the required steering angle of the vehicle.

[0037] Furthermore, the selection of the target tracking point is as follows:

[0038] The vehicle's real-time driving speed is obtained. Based on the relationship curve between the preset first limit distance and the driving speed, the first limit distance is matched and obtained. Based on the vehicle's current coordinates and the timing of the tracking points, the tracking points that are farther from the vehicle than the first limit distance are selected as the target tracking points.

[0039] As described above, the distance to the target tracking point is positively correlated with the vehicle speed. The faster the speed and the farther the target, the smaller the steering control amplitude, which makes it more stable to control the vehicle to drive toward the target point, avoid steering vibration, and is more reasonable.

[0040] Furthermore, the selection of the target tracking point is as follows:

[0041] Calculate the curvature of the vehicle's current position in the tracking route. Calculate the second limiting distance according to the preset relationship equation between the curvature and the second limiting distance. The larger the curvature, the larger the second limiting distance. Based on the vehicle's current coordinates and the timing of the tracking points, select a tracking point whose distance from the vehicle is less than the second limiting distance as the target tracking point.

[0042] As described above, the selection of the target tracking point is negatively related to the curvature of the vehicle's current position. The greater the curvature, the more the vehicle's current driving route tends to be straight, and a tracking point farther away can be selected as the target tracking point. Otherwise, it tends to be curved, and a tracking point closer to the target tracking point needs to be selected. This can avoid the problem of the vehicle turning into the inner lane when turning because the distance of the target tracking point is too large.

[0043] Please refer to Figure 2 A driverless front-wheel steering reversing tracking control terminal includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps:

[0044] S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates.

[0045] S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking positioning point;

[0046] S3. Calculate the steering wheel angle based on the steering angle and control the steering wheel.

[0047] As can be seen from the above description, the beneficial effects of the present invention are as follows: The unmanned front-wheel steering reversing tracking control terminal of the present invention performs offset calculation on the coordinates of the satellite positioning point during reversing and performs subsequent control calculations based on the offset positioning point coordinates after offset calculation, thereby avoiding the problem of positioning lag and inaccurate reversing tracking driving caused by the vehicle positioning point being set in the middle of the steering wheel.

[0048] Furthermore, the positioning point offset algorithm is specifically as follows:

[0049] Longitude_offset=Longitude+sin(direction_angle_offset)*car_len;

[0050] Latitude_offset=Latitude+cos(direction_angle_offset)*car_len;

[0051]

[0052] Wherein, direction_angle_offset represents the offset direction angle, direction_angle represents the original direction angle, the original direction angle is the angle formed by rotating clockwise from due north in the latitude and longitude coordinate system, Longitude_offset represents the longitude after offset, Longitude represents the original longitude, car_len represents the length of the car body, Latitude_offset represents the latitude after offset, and Latitude represents the original latitude.

[0053] As can be seen from the above description, the offset of the positioning point can be calculated using the above formula.

[0054] Further, step S2 includes the following steps:

[0055] S21. Based on the offset positioning point coordinates obtained in real time, calculate the vehicle's reversing direction and establish a latitude and longitude coordinate system, which includes the target tracking point coordinates.

[0056] S22. Based on the offset direction angle, the latitude and longitude coordinate system is transformed to obtain the vehicle body coordinate system, and the required steering angle of the vehicle is calculated based on the vehicle body coordinate system.

[0057] As described above, based on the offset positioning point coordinates obtained from the offset calculation, a latitude and longitude coordinate system is established. By transforming the vehicle body coordinate system and the offset direction angle model coordinate system, the target tracking point is converted and fixed in the vehicle body coordinate system, thereby determining the required steering angle of the vehicle.

[0058] Furthermore, the selection of the target tracking point is as follows:

[0059] The vehicle's real-time driving speed is obtained. Based on the relationship curve between the preset first limit distance and the driving speed, the first limit distance is matched and obtained. Based on the vehicle's current coordinates and the timing of the tracking points, the tracking points that are farther from the vehicle than the first limit distance are selected as the target tracking points.

[0060] As can be seen from the above description, the selection distance of the target tracking point is positively correlated with the vehicle speed. The faster the speed and the farther the target, the smaller the steering control amplitude, and the more stable the control can be to drive towards the target point, avoiding steering vibration and making it more reasonable.

[0061] Furthermore, the selection of the target tracking point is as follows:

[0062] Calculate the curvature of the vehicle's current position in the tracking route. Calculate the second limiting distance according to the preset relationship equation between the curvature and the second limiting distance. The larger the curvature, the larger the second limiting distance. Based on the vehicle's current coordinates and the timing of the tracking points, select a tracking point whose distance from the vehicle is less than the second limiting distance as the target tracking point.

[0063] As described above, the selection of the target tracking point is negatively related to the curvature of the vehicle's current position. The greater the curvature, the more the vehicle's current driving route tends to be straight, and a tracking point farther away can be selected as the target tracking point. Otherwise, it tends to be curved, and a tracking point closer to the target tracking point needs to be selected. This can avoid the problem of the vehicle turning into the inner lane when turning because the distance of the target tracking point is too large.

[0064] The present invention provides a tracking control method and terminal for unmanned front-wheel steering reversing, applicable to scenarios where unmanned vehicles with front-wheel steering need to perform reversing tracking control.

[0065] Please refer to Figure 1 , Figure 3 and Figure 4 Embodiment 1 of the present invention is as follows:

[0066] A tracking control method for an unmanned front-wheel steering reversing vehicle includes the following steps:

[0067] S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates.

[0068] The positioning point offset algorithm is specifically as follows:

[0069] Longitude_offset=Longitude+sin(direction_angle_offset)*car_len;

[0070] Latitude_offset=Latitude+cos(direction_angle_offset)*car_len;

[0071]

[0072] Wherein, direction_angle_offset represents the offset direction angle, direction_angle represents the original direction angle, the original direction angle is the angle formed by rotating clockwise from due north in the latitude and longitude coordinate system, Longitude_offset represents the longitude after offset, Longitude represents the original longitude, car_len represents the length of the car body, Latitude_offset represents the latitude after offset, and Latitude represents the original latitude.

[0073] In this embodiment, the autonomous vehicle employs an unmanned drive-by-wire chassis, including steering control, speed control, and braking control. Steering is a front-wheel steering Ackerman model. The positioning antenna is located in the center of the front steering wheel, enabling rapid response to positioning and heading changes caused by steering. The main controller receives positioning data and, based on the data processing results, controls the drive-by-wire chassis to execute actions.

[0074] Because the vehicle positioning antenna is located in the middle of the front steering wheel, directly using this positioning data for reversing tracking will cause the rear of the vehicle to deviate from the target trajectory direction when reversing, resulting in the rear of the vehicle deviating from the trajectory until the front of the vehicle reaches near the trajectory. The steering will then be readjusted, and the adjustment will cause the rear of the vehicle to deviate from the trajectory again, resulting in repeated turns and a serpentine path, which will prevent the desired function from being achieved.

[0075] Therefore, by using the above steps to shift the center positioning point of the steering wheel towards the rear of the vehicle, the positioning point is ensured to be in front of the vehicle's direction of travel, thus achieving stable control.

[0076] S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking positioning point;

[0077] The target tracking point is selected as follows:

[0078] The vehicle's real-time driving speed is obtained. Based on the relationship curve between the preset first limit distance and the driving speed, the first limit distance is matched and obtained. Based on the vehicle's current coordinates and the timing of the tracking points, the tracking points that are farther from the vehicle than the first limit distance are selected as the target tracking points.

[0079] In this embodiment, simulating the principle of manual driving—focusing on nearby objects at low speeds and distant objects at high speeds—a curve relating the distance to the target tracking point (first limiting distance) and speed is obtained, which can be referenced. Figure 3 As shown, the horizontal and vertical vehicle speeds are in km / h, and the selection distance of the target tracking point on the vertical axis is in m. The selection distance of the target tracking point (the first limiting distance) increases with the increase of speed, and the specific relationship curve can be set according to actual needs.

[0080] Step S2 includes the following steps:

[0081] S21. Based on the offset positioning point coordinates obtained in real time, calculate the vehicle's reversing direction and establish a latitude and longitude coordinate system, which includes the target tracking point coordinates.

[0082] S22. Based on the offset direction angle, the latitude and longitude coordinate system is transformed to obtain the vehicle body coordinate system, and the required steering angle of the vehicle is calculated based on the vehicle body coordinate system.

[0083] like Figure 4 As shown, in this embodiment, the vehicle is positioned using a satellite positioning system, which can determine the vehicle's real-time latitude and longitude and the vehicle's reversing direction. The reversing direction is an angle based on due north and clockwise. Thus, the vehicle's ground latitude and longitude coordinate system can be obtained from the satellite positioning system. By approximating the ground as a plane, a two-dimensional coordinate system is obtained. The latitude and longitude are calculated by offset in step S1.

[0084] Since the vehicle's offset direction angle is known, the two-dimensional latitude and longitude coordinate system can be rotated and transformed to obtain the vehicle body coordinate system, that is, the vehicle's driving direction is the y-axis direction.

[0085] Using the vehicle's own coordinate system centered at O, the angle between the target tracking point and the y-axis can be obtained. After conversion, the first steering angle (turn_angle_1) can be obtained. The calculated angle range is 0 to 360 degrees. 0 to 90 degrees means the target point is in the first quadrant and turns right. 270 to 360 degrees means the target point is in the fourth quadrant and turns left. 90 to 270 degrees means the target is behind the vehicle. Report a target error and update the target.

[0086] S3. Calculate the steering wheel angle based on the steering angle and control the steering wheel.

[0087] By corresponding the first steering angle with the steering wheel angle, for example, if the vehicle's steering wheel sway angle is ±30 degrees, when the first steering angle is 0 degrees, the corresponding steering wheel sway angle is 0 degrees, and the vehicle is driving in a straight line. When the first steering angle is 90 degrees, the corresponding steering wheel sway angle is 30 degrees, and other angles are linearly corresponding, it is possible to achieve real-time control of steering to drive in the target direction.

[0088] Embodiment 2 of the present invention is as follows:

[0089] A tracking control method for unmanned front-wheel steering reversing differs from Embodiment 1 in that the selection of the target tracking point is as follows:

[0090] Calculate the curvature of the vehicle's current position in the tracking route. Calculate the second limiting distance according to the preset relationship equation between the curvature and the second limiting distance. The larger the curvature, the larger the second limiting distance. Based on the vehicle's current coordinates and the timing of the tracking points, select a tracking point whose distance from the vehicle is less than the second limiting distance as the target tracking point.

[0091] In this embodiment, to avoid vehicles turning into the inner lane due to excessive turning detection distance, it is necessary to select the target trajectory point based on the curvature of the current vehicle's target trajectory. The radius of curvature near the target trajectory path is calculated. The smaller the radius of curvature, the closer the target trajectory point is (the second limiting distance); the larger the curvature, the greater the target trajectory point is. The specific relationship equation can be designed according to the actual situation.

[0092] Target trajectory curvature radius algorithm: Take trajectory points 5 meters before and after the target point to form a set of calculation points, p1(x1, y1), p2(x2, y2), p3(x3, y3). These three points form a triangle, and the area of ​​the triangle can be calculated.

[0093]

[0094] The circumcircle radius of the triangle is also its radius of curvature:

[0095]

[0096] Where, d 21 Let d be the distance between points (x1, y1) and (x2, y2). 23 and d 13 Similarly.

[0097] Select a tracking point whose distance from the vehicle is less than the second limit distance as the target tracking point.

[0098] Embodiment 3 of the present invention is as follows:

[0099] A tracking control method for unmanned front-wheel steering reverse vehicle, differing from Embodiment 1 or 2 in that the selection of the target tracking point is as follows:

[0100] Based on the current real-time vehicle speed and the relationship curve between the limited distance and speed in Example 1, a first limited distance is determined. Based on the radius of curvature of the vehicle's current position in the tracking trajectory and the relationship equation between curvature and the second limited distance described in Example 2, a second limited distance is determined.

[0101] In this embodiment, a second limiting distance is used to correct the first limiting distance. Generally, the second limiting distance is greater than the first limiting distance. Therefore, a trajectory point whose distance is between the first and second limiting distances is selected as the target trajectory point. If multiple trajectory points meet the conditions, they can be selected randomly, or the selection can be made according to the actual configuration, such as selecting the nearest target trajectory point.

[0102] If the second limiting distance is less than the first limiting distance, it can reflect to some extent that the current cornering speed may be too fast and there is a risk. Priority should be given to selecting based on the second limiting distance. For example, if the second limiting distance is met, the farthest tracking point is selected as the target tracking point, and the vehicle is controlled to decelerate until the second limiting distance is greater than the first limiting distance.

[0103] Embodiment four of the present invention is as follows:

[0104] An unmanned front-wheel steering reversing tracking control terminal 1 includes a processor 2, a memory 3, and a computer program stored in the memory 3 and executable on the processor 2. When the processor 2 executes the computer program, it implements the steps in Embodiments 1, 2, or 3 above.

[0105] In summary, the present invention provides a tracking control method and terminal for unmanned front-wheel steering reversing, which performs offset calculation on the coordinates of satellite positioning points during tracking reversing, and performs subsequent control calculations based on the offset positioning point coordinates after offset calculation, thus avoiding the problem of positioning lag and inaccurate reversing tracking driving caused by the vehicle positioning point being set in the middle of the steering wheel.

[0106] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention's specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A tracking control method for unmanned front-wheel steering reversing vehicle, characterized in that, Including the following steps: S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates. S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking point; S3. Calculate the steering wheel angle based on the steering angle matching, and control the steering wheel. The target tracking point is selected as follows: The vehicle's real-time speed is obtained, and the first limit distance is matched according to the preset relationship curve between the first limit distance and the speed. Calculate the curvature of the vehicle's current position in the tracking route, and calculate the second limit distance according to the preset relationship equation between the curvature and the second limit distance. The larger the curvature, the larger the second limit distance. If the second limiting distance is greater than the first limiting distance, a tracking point that is greater than the first limiting distance and less than the second limiting distance from the vehicle is selected as the target tracking point based on the vehicle's current coordinates and the tracking point timing. If the second limiting distance is less than the first limiting distance, the tracking point that is furthest away from the tracking points that are less than the second limiting distance from the vehicle is selected as the target tracking point based on the vehicle's current coordinates and the tracking point timing. The vehicle is then controlled to decelerate until the second limiting distance is greater than the first limiting distance.

2. The tracking control method for unmanned front-wheel steering reversing according to claim 1, characterized in that, The positioning point offset algorithm is specifically as follows: ； ； ； in, Indicates the offset direction angle. This represents the original direction angle, which is the angle formed by rotating clockwise from true north in the latitude and longitude coordinate system. Indicates the longitude after the offset. Indicates the original longitude. Indicates the length of the vehicle body. Indicates the latitude after the offset. Indicates the original latitude.

3. The tracking control method for unmanned front-wheel steering reversing according to claim 2, characterized in that, Step S2 includes the following steps: S21. Based on the offset positioning point coordinates obtained in real time, calculate the vehicle's reversing direction and establish a latitude and longitude coordinate system, which includes the target tracking point coordinates. S22. Based on the offset direction angle, the latitude and longitude coordinate system is transformed to obtain the vehicle body coordinate system, and the required steering angle of the vehicle is calculated based on the vehicle body coordinate system.

4. A driverless front-wheel steering reversing tracking control terminal, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it performs the following steps: S1. Obtain the vehicle positioning point coordinates in real time through satellite positioning, and use the positioning point offset algorithm to offset the positioning point in the middle of the front steering wheel to the rear of the vehicle to obtain the offset positioning point coordinates. S2. Calculate the turning angle based on the coordinates of the offset positioning point and the target tracking point; S3. Calculate the steering wheel angle based on the steering angle matching, and control the steering wheel. The target tracking point is selected as follows: The vehicle's real-time speed is obtained, and the first limit distance is matched according to the preset relationship curve between the first limit distance and the speed. Calculate the curvature of the vehicle's current position in the tracking route, and calculate the second limit distance according to the preset relationship equation between the curvature and the second limit distance. The larger the curvature, the larger the second limit distance. If the second limiting distance is greater than the first limiting distance, a tracking point that is greater than the first limiting distance and less than the second limiting distance from the vehicle is selected as the target tracking point based on the vehicle's current coordinates and the tracking point timing. If the second limiting distance is less than the first limiting distance, the tracking point that is furthest away from the tracking points that are less than the second limiting distance from the vehicle is selected as the target tracking point based on the vehicle's current coordinates and the tracking point timing. The vehicle is then controlled to decelerate until the second limiting distance is greater than the first limiting distance.

5. A tracking control terminal for unmanned front-wheel steering reversing according to claim 4, characterized in that, The positioning point offset algorithm is specifically as follows: ； ； ； in, Indicates the offset direction angle. This represents the original direction angle, which is the angle formed by rotating clockwise from true north in the latitude and longitude coordinate system. Indicates the longitude after the offset. Indicates the original longitude. Indicates the length of the vehicle body. Indicates the latitude after the offset. Indicates the original latitude.

6. The unmanned front-wheel steering reversing tracking control terminal according to claim 5, characterized in that, Step S2 includes the following steps: S21. Based on the offset positioning point coordinates obtained in real time, calculate the vehicle's reversing direction and establish a latitude and longitude coordinate system, which includes the target tracking point coordinates. S22. Based on the offset direction angle, the latitude and longitude coordinate system is transformed to obtain the vehicle body coordinate system, and the required steering angle of the vehicle is calculated based on the vehicle body coordinate system.

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