Dual-vehicle linkage control method with laser radar installed at the rear end of the front vehicle

Abstract

The present invention relates to a dual-vehicle linkage control method in which a laser radar is arranged at the rear end of a front vehicle, and the method is applied to a front-rear dual-vehicle linkage system, wherein the front-rear dual-vehicle linkage system comprises a front vehicle and a rear vehicle in the traveling direction; wherein the rear end of the front vehicle is provided with a laser radar and the front end of the rear vehicle is provided with left and right reflectors; the method comprises: identifying the left and right reflectors based on the laser radar, calculating the relative positions of the front and rear vehicles, solving dual-vehicle linkage control parameters based on the relative position information and linkage control instructions when the dual vehicles are in a translation mode and a rotation mode, and performing dual-vehicle linkage control based on the solved dual-vehicle linkage control parameters, thereby improving the synchronization performance of the two vehicles while having a simpler structure and lower cost.

Description

[0001] The present application is a divisional application of the applicant's prior application, the application number of which is CN202410606954.0, and the application name is A dual-vehicle linkage control method. Technical Field

[0002] The present invention relates to the technical field of intelligent transport equipment control systems, and in particular to a dual-vehicle linkage control method in which a laser radar is arranged at the rear end of a front vehicle. Background Art

[0003] In the field of heavy-load AGVs, the omnidirectional motion model is a mobile chassis with a more flexible motion effect. Among the omnidirectional motion models, the four-steering wheel model has the characteristics of high precision, heavy load and simple control.

[0004] In the field of heavy-load AGVs, most of the large equipment that actually needs to be transported are overweight, overlong, and overwide. In this context, the limitations of single-vehicle transportation have gradually become apparent, and the split-type double-vehicle linkage transportation solution has been proposed and applied to a certain extent.

[0005] There are currently two main technical solutions for dual-vehicle linkage. One is to send the same control command to two different vehicles at the same time, including starting, moving, and stopping at the same time. However, since the actual operating conditions of the two vehicles are not taken into consideration, the synchronization of the two vehicles cannot be guaranteed. The other is to treat the two vehicles as a whole and recalculate the speed of the driving wheels of the two vehicles. However, there is no control closed-loop correction of the relative positions of the two vehicles, and there will be accumulated errors, which makes it impossible to guarantee the accuracy of the dual-vehicle linkage for a long time. Summary of the invention

[0006] The technical problem to be solved by the present application is to provide a dual-vehicle linkage control method, which has the characteristic of improving the synchronization performance of the two vehicles in front and behind.

[0007] In one embodiment, a dual-vehicle linkage control method is provided, which is applied to a front-rear dual-vehicle linkage system, wherein the front-rear dual-vehicle linkage system includes a front vehicle and a rear vehicle in the traveling direction; wherein a laser radar is provided at the rear end of the front vehicle and left and right reflectors are provided at the front end of the rear vehicle, or, left and right reflectors are provided at the rear end of the front vehicle and a laser radar is provided at the front end of the rear vehicle; the method includes:

[0008] Based on the laser radar, the left and right reflectors are identified and the relative positions of the front and rear vehicles are calculated;

[0009] The dual-vehicle linkage control parameter calculation is performed based on the relative position information and the linkage control instruction, including:

[0010] In the non-rotating translation mode of the front and rear vehicles, that is, controlling the angular velocity In the case of , the dual-vehicle linkage control parameter calculation includes:

[0011] Get the speed in the same direction as the vehicle head and the speed perpendicular to the vehicle head;

[0012] Based on the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction, calculating the translation speed and translation angle in the translation mode;

[0013] Based on the translation speed, the speeds of the front, rear, left, and right wheels of the front vehicle and the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained; based on the translation angle, the steering wheel deflection angles of the front, rear, left, and right wheels of the front vehicle and the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle are obtained;

[0014] In the non-translational rotation mode of the front and rear vehicles, that is, controlling the angular velocity In the case of , the dual-vehicle linkage control parameter calculation includes:

[0015] Get the wheelbase and track width of the front and rear vehicles;

[0016] Calculate the distance between the two vehicles based on the information of the relative positions of the front and rear vehicles;

[0017] Based on the wheelbase, track width and distance between the front and rear vehicles, the turning radius and steering wheel deflection angle of the front vehicle's front, rear, left and right wheels are calculated, and the turning radius and steering wheel deflection angle of the rear vehicle's front, rear, left and right wheels are calculated;

[0018] Based on the control angular velocity and the rotation radius of the front vehicle's front, rear, left, and right wheels, the speed of the front vehicle's front, rear, left, and right wheels is calculated; based on the control angular velocity and the rotation radius of the front, rear, left, and right wheels of the rear vehicle's front, rear, left, and right wheels, the speed of the rear vehicle's front, rear, left, and right wheels is calculated;

[0019] The double-vehicle linkage control is performed based on the calculated double-vehicle linkage control parameters.

[0020] The beneficial effects of the present invention are:

[0021] Because the laser radar installed on one of the two vehicles recognizes the left and right reflectors installed on the other vehicle, the relative positions of the two vehicles are obtained, and the dual-vehicle linkage control parameters are solved in combination with the control instructions to obtain the actual control speed and deflection angle required by the four steering wheels of the front and rear vehicles. This improves the synchronization performance of the two vehicles while making the structure simpler and the cost lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a linkage system for rear vehicle identification reflectors according to an embodiment of the present application;

[0023] Figure 2 It is a schematic diagram of a linkage system for a front vehicle identification reflector according to an embodiment of the present application;

[0024] Figure 3It is a method flow diagram of one embodiment of the method of the present application;

[0025] Figure 4 This application Figure 3 A method flow diagram of an embodiment of step S10;

[0026] Figure 5 This application Figure 3 A schematic diagram of a method flow chart of another embodiment of step S10;

[0027] Figure 6 This application Figure 3 A method flow diagram of an embodiment of step S20;

[0028] Figure 7 is a schematic diagram of a system in a dual-car translation mode according to an embodiment of the present application;

[0029] Figure 8 is a schematic diagram of a system in a dual-car rotation mode according to an embodiment of the present application;

[0030] Fig. 9 This application Figure 3 A schematic diagram of a method flow of a second embodiment of step S20;

[0031] Fig.10 This application Figure 3 A schematic diagram of a method flow chart of a third embodiment of step S20;

[0032] Fig.11 This is a state diagram of a situation where two vehicles deviate from each other in one embodiment of the present application. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0034] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0035] The serial numbers assigned to the components in this article, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning.

[0036] To facilitate the description of the inventive concept of the present application, the dual-vehicle linkage technology is briefly described below.

[0037] In the current dual-vehicle linkage scheme, most of them use cameras to identify the laser beam emitted by the laser beacon transmitter to obtain the position deviation of the two vehicles, and use a laser rangefinder to obtain the distance deviation of the two vehicles, so as to achieve linkage control based on these two deviations. However, the applicant found in the research that in this type of scheme, on the one hand, it is affected by the camera's viewing angle, and the range of the position deviation of the two vehicles that can be identified is limited, and a two-dimensional turntable is required to rotate the laser beacon transmitter for auxiliary identification; on the other hand, the camera cannot obtain the actual position and angle deviation of the two vehicles, and can only judge the deviation direction and estimate the deviation size through the pixel point difference. Therefore, it is impossible to solve the specific vehicle motion model speed, resulting in the inability to better improve the synchronization performance of the two vehicles.

[0038] In view of this, the present application provides a dual-vehicle linkage control method, which is based on the laser radar set on one of the two vehicles recognizing the left and right reflective panels set on the other vehicle, obtaining the relative positions of the two vehicles, and then combining the control instructions to solve the dual-vehicle linkage control parameters, and obtaining the actual control speed and deflection angle required by the four steering wheels of the front and rear vehicles, thereby improving the synchronization performance of the two vehicles.

[0039] In order to better explain the double-vehicle linkage control method, the following first describes the front and rear double-vehicle linkage system used. Figure 1 and Figure 2 In this front and rear double-vehicle linkage system, the following can be used: Figure 1 The linkage system of the rear vehicle identification reflector shown in FIG. Figure 2 The linkage system of the front vehicle identification reflector shown in FIG. Figure 1 In the linkage system for rear vehicle identification reflectors shown in FIG, the rear end of the front vehicle is provided with left and right reflectors and the front end of the rear vehicle is provided with a laser radar. Figure 2In the linkage system for the front vehicle to identify the reflector, a laser radar is provided at the rear end of the front vehicle and left and right reflectors are provided at the front end of the rear vehicle. The laser radar can rotate to emit laser to the left and right reflectors. In one embodiment, the laser radar can rotate 360 ​​degrees.

[0040] Since the laser radar can obtain the light intensity value of the reflected laser beam based on the reflectivity of the scanned object, and according to physical properties, the reflectivity of the reflector to light is significantly higher than that of other materials, the laser radar can identify the left and right reflectors installed symmetrically along the central axis of the vehicle body.

[0041] By filtering out other laser beams except the reflector according to the light intensity value, the coordinates of the left and right reflectors in the laser radar coordinate system can be directly obtained.

[0042] In one embodiment, the front and rear dual-vehicle linkage system also includes a remote control, and the front vehicle control center or the rear vehicle control center receives the control command of the remote control, and calculates the dual-vehicle linkage control parameters based on the control command and the relative positions of the two vehicles, thereby realizing the linkage control of the two vehicles based on the calculated control parameters.

[0043] In one embodiment, the remote control command of the remote controller includes controlling the angular velocity, the velocity in the same direction as the vehicle head direction, and the velocity perpendicular to the vehicle head direction.

[0044] For the front and rear dual-vehicle linkage system based on any of the above embodiments, please refer to Figure 3 , a dual-vehicle linkage control method includes:

[0045] Step S10, based on the laser radar, the left and right reflectors are identified and the relative positions of the front and rear vehicles are calculated.

[0046] In one embodiment, please refer to Figure 4 In a dual-vehicle linkage system, when the rear end of the front vehicle is provided with left and right reflectors and the front end of the rear vehicle is provided with a laser radar, the relative positions of the front and rear vehicles are calculated based on the laser radar identifying the left and right reflectors, including:

[0047] Step S1011, calculating the center point of the left and right reflectors at the rear end of the front vehicle in the radar coordinate system, and the angle of the vertical line connecting the left and right reflectors at the rear end of the front vehicle in the radar coordinate system.

[0048] In one embodiment, it includes:

[0049] , ,

[0050] ,

[0051] in, It represents the x-coordinate of the center point of the left and right reflectors at the rear end of the front vehicle in the radar coordinate system. Indicates the y coordinate of the center point of the left and right reflectors at the rear end of the front vehicle in the radar coordinate system, It indicates the angle of the vertical line connecting the left and right reflectors at the rear end of the front vehicle in the radar coordinate system. It represents the x-coordinate of the left reflector at the rear end of the front vehicle in the radar coordinate system. Indicates the y coordinate of the left reflector at the rear end of the front vehicle in the radar coordinate system, It represents the x-coordinate of the right reflector at the rear end of the front vehicle in the radar coordinate system. Indicates the y coordinate of the right reflector at the rear end of the front vehicle in the radar coordinate system.

[0052] Please refer to Figure 1 , through the coordinates of the left and right reflectors, the coordinates of the midpoint O3 of the two reflectors behind the front vehicle body in the radar coordinate system O2 can be calculated and , where the direction of the O3 coordinate system is perpendicular to the line connecting the left and right reflectors, that is, the angle in the O2 coordinate system is .

[0053] In this way, the necessary conditions for converting the front vehicle control center coordinate system O4 to the rear vehicle control center coordinate system O1 have been obtained, that is, the origin coordinates of the front vehicle control center system O4 are converted to the left and right reflector symmetry center coordinate system O3, and then the coordinates of the left and right reflector symmetry center coordinate system O3 are converted to the laser radar coordinate system O2, and finally the coordinates of the laser radar coordinate system O2 are converted to the rear vehicle control center coordinate system O1.

[0054] It is known (from the mechanical parameters) that the coordinates of the origin of the control center coordinate system O4 of the front vehicle in the symmetric center coordinate system O3 of the left and right reflectors are P5 ( , , ), create a new coordinate system with the same origin as O3 and the direction as New coordinate system .

[0055] For the convenience of calculation, let point P5 be expressed in polar coordinates as ( , ),in

[0056] , ,

[0057] , ,

[0058] Use polar coordinates to express P5 in the new coordinate system The coordinates of P5 are The coordinates of , ) can be expressed as ( , ).

[0059] Then there is

[0060] ,

[0061] ,

[0062] The simplified expression is:

[0063] ,

[0064] Assume that the point from the origin of the front vehicle control center coordinate system O4 to the laser radar coordinate system O2 is ( , ), from the above calculation, we can know that the coordinate system With respect to the laser radar coordinate system O2, the X-axis translation is , the Y-axis translation is , so through translation transformation we get:

[0065] ,

[0066] Step S1012, based on the coordinates of the center point of the left and right reflectors at the rear end of the front vehicle in the radar coordinate system, and the angle of the vertical line connecting the left and right reflectors at the rear end of the front vehicle in the radar coordinate system, calculate the coordinates and angle of the control center point of the front vehicle in the control center coordinate system of the rear vehicle.

[0067] In one implementation, based on the embodiment of step S1011, the coordinates and angles of the control center point of the leading vehicle in the coordinate system of the control center of the trailing vehicle can be calculated to include:

[0068] ,

[0069] ,

[0070] in, , and They represent the x-coordinate, y-coordinate and angle of the front vehicle control center in the rear vehicle control center coordinate system. and They represent the x-coordinate and y-coordinate of the front vehicle control center point in the symmetrical center coordinate system of the left and right reflectors, , and They respectively represent the x-coordinate, y-coordinate and angle of the laser radar under the control center of the rear vehicle.

[0071] Among them, the direction of the symmetric center coordinate system of the left and right reflectors is perpendicular to the line connecting the left and right reflectors, and the positive direction of the y-axis is vertical to the left. The control center coordinate system of the front vehicle has the same direction as the symmetric center coordinate system of the left and right reflectors. When the front vehicle and the rear vehicle are aligned front and back, the symmetric center coordinate system of the left and right reflectors has the same direction as the radar coordinate system, and the control center coordinate system of the rear vehicle has the same direction as the radar coordinate system.

[0072] Step S1013, based on the coordinates and angles of the leading vehicle control center point in the trailing vehicle control center coordinate system, obtain the coordinates and orientation of the leading vehicle control center coordinate system in the trailing vehicle control center coordinate system.

[0073] In one embodiment, it includes: using the coordinates and angle of the front vehicle control center point in the rear vehicle control center coordinate system as the coordinates and orientation of the front vehicle control center coordinate system in the rear vehicle control center coordinate system.

[0074] Step S1014, taking the coordinates and orientation of the control center coordinate system of the front vehicle in the control center coordinate system of the rear vehicle as the relative positions of the front and rear vehicles.

[0075] In one embodiment, please refer to Figure 5 In a dual-vehicle linkage system, when a laser radar is provided at the rear end of the front vehicle and left and right reflectors are provided at the front end of the rear vehicle, the relative positions of the front and rear vehicles are calculated based on the laser radar identifying the left and right reflectors, including:

[0076] Step S1021, calculating the coordinates of the center point of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, and the angle of the vertical line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system.

[0077] In one embodiment, it includes:

[0078] , ,

[0079] ,

[0080] in, It represents the x-coordinate of the center point of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system. Indicates the y coordinate of the center point of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, It indicates the angle of the vertical line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system. Indicates the x-coordinate of the left reflector at the front end of the rear vehicle in the radar coordinate system, Indicates the y coordinate of the left reflector at the front end of the rear vehicle in the radar coordinate system, It represents the x-coordinate of the right reflector at the front end of the rear vehicle in the radar coordinate system. Indicates the y coordinate of the right reflector at the front end of the rear vehicle in the radar coordinate system.

[0081] Step S1022, based on the coordinates of the center points of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, and the angle of the vertical line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, calculate the coordinates and angle of the control center point of the rear vehicle in the control center coordinate system of the front vehicle.

[0082] Please refer to Figure 2 Similarly, based on the analysis of step S1011 and step S1021, in one embodiment, the calculated coordinates and angles of the rear vehicle control center point in the front vehicle control center coordinate system include:

[0083] ,

[0084] ,

[0085] in, , and They represent the x-coordinate, y-coordinate and angle of the rear vehicle control center point in the front vehicle control center coordinate system. and They represent the x-coordinate and y-coordinate of the rear vehicle control center point in the symmetrical center coordinate system of the left and right reflectors, respectively. They can be obtained based on the mechanical parameters. , and They represent the x-coordinate, y-coordinate and angle of the laser radar under the control center of the preceding vehicle, respectively, and can be obtained according to the mechanical parameters;

[0086] Among them, the direction of the symmetric center coordinate system of the left and right reflectors is perpendicular to the line connecting the left and right reflectors, and the positive direction of the y-axis is vertical to the left. The control center coordinate system of the rear vehicle has the same direction as the symmetric center coordinate system of the left and right reflectors. When the front and rear vehicles are aligned front and back, the symmetric center coordinate system of the left and right reflectors has the same direction as the radar coordinate system, and the control center coordinate system of the front vehicle has the same direction as the radar coordinate system.

[0087] Step S1023, based on the coordinates and angles of the rear vehicle control center point in the front vehicle control center coordinate system, obtain the coordinates and orientation of the front vehicle control center coordinate system in the rear vehicle control center coordinate system.

[0088] Please refer to Figure 2 In the embodiment, since the directions of the O1 coordinate system and the O2 coordinate system are the same, and the directions of the O3 coordinate system and the O4 coordinate system are also the same, , the coordinates and orientation of the rear vehicle control center coordinate system in the front vehicle control center coordinate system can be obtained as follows:

[0089] ,

[0090] in, , and They respectively represent the x-coordinate, y-coordinate and direction of the front vehicle control center coordinate system in the rear vehicle control center coordinate system.

[0091] Step S1024, taking the coordinates and orientation of the control center coordinate system of the front vehicle in the control center coordinate system of the rear vehicle as the relative positions of the front and rear vehicles.

[0092] Step S20, based on the relative position information and the linkage control instruction, the dual-vehicle linkage control parameter solution is performed. In one embodiment, the dual-vehicle linkage control parameter solution is performed in a translation mode where the front and rear vehicles are non-rotating and in a rotation mode where the front and rear vehicles are non-translating.

[0093] Please refer to Figure 6 , in the non-rotating translation mode of the front and rear vehicles, that is, the control angular velocity in the control command of the remote control In the case of , the dual-vehicle linkage control parameter solution can include:

[0094] Step S2011, obtaining the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction.

[0095] The speed in the same direction as the front direction of the vehicle and the speed perpendicular to the front direction of the vehicle are controlled by the remote control command. The premise of the dual-vehicle linkage is that the relative posture of the front vehicle and the rear vehicle first reaches the desired posture. In one embodiment, due to manual remote control, the position accuracy of the rear vehicle cannot be guaranteed. The four-steering wheel motion model can control the translation and rotation of the vehicle at the same time. The two vehicles in the dual-vehicle linkage are flexibly connected. As long as the control accuracy of one of the steering wheel angles is insufficient, the two vehicles will deviate as a whole and it will be difficult to correct. In one embodiment, the speed solution of the dual-vehicle linkage is simplified to only consider the two states of rotation and non-rotation.

[0096] In one embodiment, please refer to Figure 7 , the control angular velocity of the linkage control center of the manual remote control In the case of double-car translation mode, only the speed in the same direction of the front direction can be considered. and the speed perpendicular to the direction of the vehicle head .

[0097] Step S2012, based on the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction, the translation speed and the translation angle in the translation mode are calculated.

[0098] In one embodiment, it includes:

[0099] , ,

[0100] in, and Respectively represent the translation speed and translation angle in translation mode, and They respectively represent the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction in the remote control command.

[0101] Step S2013, based on the translation speed, obtain the speed of the front vehicle's front, rear, left, and right four wheels and the speed of the rear vehicle's front, rear, left, and right four wheels, and based on the translation angle, obtain the steering wheel deflection angle of the front vehicle's front, rear, left, and right four wheels and the steering wheel deflection angle of the rear vehicle's front, rear, left, and right four wheels.

[0102] In one embodiment, it includes:

[0103] , , , ,

[0104] , , , ,

[0105] , , , ,

[0106] , , , ,

[0107] in, Indicates the speed of the front right wheel of the vehicle in front. Indicates the front left wheel speed of the vehicle ahead. Indicates the speed of the rear right wheel of the front vehicle. Indicates the speed of the rear left wheel of the front vehicle. Indicates the speed of the front right wheel of the rear vehicle. Indicates the speed of the front left wheel of the rear vehicle. Indicates the speed of the rear right wheel of the following vehicle. Indicates the speed of the rear left wheel of the following vehicle. Indicates the steering wheel deflection angle of the front right wheel of the front vehicle. Indicates the steering wheel deflection angle of the front left wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the front vehicle. Indicates the steering wheel deflection angle of the front right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the front left wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the following vehicle.

[0108] The 8 sets of steering wheels controlled by the two vehicles have the same angle and speed, ensuring that the direction and speed of the vehicle body translation are consistent.

[0109] Please refer to Figure 8 , in the non-translational rotation mode of the front and rear vehicles, that is, controlling the angular velocity In the case of , the angular velocity of the control needs to be considered so that the two vehicles rotate along the rotation center O at the same time. For an embodiment, please refer to Fig. 9 , the dual-vehicle linkage control parameter calculation includes:

[0110] Step S2021, obtaining the wheelbase and track width of the front and rear vehicles.

[0111] In one embodiment, the wheelbase and track width of the front and rear vehicles are the same.

[0112] Step S2022, calculating the distance between the two vehicles based on the relative position information of the front and rear vehicles.

[0113] Based on the information of the relative positions of the two vehicles, those skilled in the art can easily calculate the distance between the two vehicles using the calculation method of the prior art, which will not be described in detail here.

[0114] Step S2023, based on the wheelbase, track width and distance between the front and rear vehicles, calculate the rotation radius and steering wheel deflection angle of the front vehicle's front, rear, left and right wheels, and calculate the rotation radius and steering wheel deflection angle of the rear vehicle's front, rear, left and right wheels.

[0115] In one embodiment, the method comprises:

[0116] ,

[0117] ,

[0118] ,

[0119] ,

[0120] in, Indicates the wheelbase, Indicates wheelbase, Indicates the distance between two vehicles. The wheelbase and track width of the front and rear vehicles are the same; Indicates the turning radius of the front right wheel of the front vehicle. Indicates the turning radius of the front left wheel of the front vehicle. Indicates the rotation radius of the rear right wheel of the front vehicle. Indicates the rotation radius of the rear left wheel of the front vehicle. Indicates the rotation radius of the front right wheel of the rear vehicle. Indicates the turning radius of the front left wheel of the rear vehicle. Indicates the rotation radius of the rear right wheel of the following vehicle. Indicates the rotation radius of the rear left wheel of the following vehicle. Indicates the steering wheel deflection angle of the front right wheel of the front vehicle. Indicates the steering wheel deflection angle of the front left wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the front vehicle. Indicates the steering wheel deflection angle of the front right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the front left wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the following vehicle.

[0121] Step S2024, based on the control angular velocity and the rotation radius of the front vehicle's front, rear, left, and right wheels, calculate the speed of the front, rear, left, and right wheels of the front vehicle; based on the control angular velocity and the rotation radius of the front, rear, left, and right wheels of the rear vehicle, calculate the speed of the front, rear, left, and right wheels of the rear vehicle.

[0122] In one embodiment, it includes:

[0123] , , , ,

[0124] , , , ,

[0125] in, Indicates the speed of the front right wheel of the vehicle in front. Indicates the front left wheel speed of the vehicle ahead. Indicates the speed of the rear right wheel of the front vehicle. Indicates the speed of the rear left wheel of the front vehicle. Indicates the speed of the front right wheel of the rear vehicle. Indicates the speed of the front left wheel of the rear vehicle. Indicates the speed of the rear right wheel of the following vehicle. Indicates the speed of the rear left wheel of the following vehicle.

[0126] During the research, the applicant found that in the process of dual-vehicle linkage, whether in rotation or translation mode, although the dual-vehicle linkage speed solution has been simplified during actual control, problems such as wheel slippage, inconsistent actual steering wheel angle or speed control will still occur, resulting in deviation of the dual-vehicle bodies. If there is no correction and fine-tuning algorithm, the two vehicles will deviate further and further.

[0127] In view of this, in one embodiment, please refer to Fig.10, step S20 may further include:

[0128] Step S2031, obtaining the x-coordinate, y-coordinate and angle that the control center point of the rear vehicle is expected to maintain in the coordinate system of the control center of the front vehicle, as well as the current x-coordinate, y-coordinate and angle.

[0129] Please refer to Fig.11 The premise of the dual-vehicle linkage is that the relative posture of the front vehicle and the rear vehicle first reaches the desired posture, but the position accuracy of the rear vehicle cannot be guaranteed in the case of manual remote control. In one embodiment, the position of the front vehicle is used as a reference to convert the position of the rear vehicle to the coordinate system of the front vehicle. Since the position that the rear vehicle should maintain can be the rear of the origin of the coordinate system of the control center of the front vehicle plus half of the wheelbase of the front vehicle, plus the spacing of the dual-vehicle linkage, plus half of the wheelbase of the rear vehicle, then:

[0130] ,

[0131] ,

[0132] ,

[0133] in, Indicates wheelbase, Indicates the distance between two cars, the wheelbase of the front and rear cars is the same; , and They respectively represent the x-coordinate, y-coordinate and angle that the rear vehicle control center point is expected to maintain in the front vehicle control center coordinate system.

[0134] Step S2032, calculating the relative x coordinate, relative y coordinate and relative angle of the x coordinate, y coordinate and angle that are expected to be maintained relative to the current x coordinate, y coordinate and angle.

[0135] In one embodiment, the relative coordinates between the origin of the rear vehicle control center coordinate system and the position point that is expected to be maintained are revised, and then:

[0136] ,

[0137] ,

[0138] ,

[0139] in, , and Respectively represent the current x-coordinate, y-coordinate and angle, , and They represent the relative x-coordinate, relative y-coordinate, and relative angle respectively.

[0140] In one embodiment, in the translation mode where the front and rear vehicles are non-rotating, the translation deviation correction can be divided into position correction and angle correction. In the position correction, in one embodiment, the forward direction of the vehicle body can be firstly It is divided into two partitions, among which, Set as X deviation partition, Set as Y deviation partition, then:

[0141] Step S203311, if the forward direction of the vehicle body belongs to the X deviation zone, the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation speed and the relative X coordinate, and the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation angle and the relative angle.

[0142] If the vehicle is moving in the direction , then the forward direction Belongs to the X deviation partition; based on the translation speed and relative X coordinate, the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained, including:

[0143] ,

[0144] ,

[0145] ,

[0146] ,

[0147] As for angle correction, it can be known from the calculation of the single vehicle speed that when the control angles of the front and rear wheels are opposite, the vehicle body angle will be adjusted. Therefore, the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle can be fine-tuned based on the translation angle and relative angle:

[0148] ,

[0149] ,

[0150] ,

[0151] ,

[0152] in, Indicates the translation speed in translation mode. and Represent the relative x coordinate and relative angle respectively, Represents the error correction coefficient, which is determined according to the speed of error correction. Indicates the speed of the front right wheel of the rear vehicle. Indicates the speed of the front left wheel of the rear vehicle. Indicates the speed of the rear right wheel of the following vehicle. Indicates the speed of the rear left wheel of the following vehicle. Indicates the steering wheel deflection angle of the front right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the front left wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the following vehicle.

[0153] Step S203312, if the forward direction of the vehicle body belongs to the Y deviation partition, the speed of the front, rear, left and right wheels of the rear vehicle is obtained based on the translation speed and the relative Y coordinate, and the steering wheel deflection angle of the front, rear, left and right wheels of the rear vehicle is obtained based on the translation angle and the relative angle.

[0154] If the vehicle is moving in the direction , then the forward direction Belongs to the Y deviation partition; based on the translation speed and the relative Y coordinate, the speed of the front, rear, left, and right wheels of the rear vehicle is obtained; based on the translation angle and the relative angle, the steering wheel deflection angle of the front, rear, left, and right wheels of the rear vehicle is obtained, including:

[0155] ,

[0156] ,

[0157] ,

[0158] ,

[0159] ,

[0160] ,

[0161] ,

[0162] ,

[0163] in, Relative y coordinate.

[0164] Those skilled in the art will appreciate that step S203311 and step S203312 may be performed in any order.

[0165] In the rotation mode where the front and rear vehicles are non-translational:

[0166] Step S203321, calculate the steering wheel speed of the following vehicle based on the current rotation radius, control angular velocity and relative angle.

[0167] Since the position deviation cannot be corrected during the rotation of the vehicle body, only the angle deviation is considered when the two vehicles rotate. Similarly, in one embodiment, the front vehicle maintains the control value of the two vehicle rotation solution, and uses the rear vehicle to correct the error. When there is an error in the rotation of the two vehicles, the angular velocity of the rear vehicle is increased or decreased to correct the angular error between the two vehicles. Then, based on the current rotation radius, control angular velocity and relative angle, the steering wheel speed of the rear vehicle is calculated, including:

[0168] ,

[0169] ,

[0170] ,

[0171] ,

[0172] in, Indicates the rotation radius of the front right wheel of the rear vehicle. Indicates the turning radius of the front left wheel of the rear vehicle. Indicates the rotation radius of the rear right wheel of the following vehicle. Indicates the turning radius of the rear left wheel of the following vehicle.

[0173] Step S30, performing dual-vehicle linkage control based on the calculated dual-vehicle linkage control parameters.

[0174] In the above-mentioned embodiment of the present application, only one controller and one laser radar sensor are needed, the cost is low, and the front vehicle and the rear vehicle can be interchanged and combined at will. The laser radar sensor solution used can obtain the recognition results of all angles within the unobstructed range, and the laser radar sensor can directly obtain the actual distance value and light intensity value of all light beam measurements, and it is very easy to obtain the coordinates of the recognized object relative to the laser radar sensor, and it can also switch between the master vehicle identifying the slave vehicle and the slave vehicle identifying the master vehicle. A detailed speed solution process based on the four-steering wheel motion model and a solution process for how to decompose the error correction value to the wheel after an error occurs during the dual-vehicle linkage process are provided. While improving the synchronization performance of the front and rear vehicles, the structure is also simpler and the cost is lower.

[0175] In one embodiment of the present application, a computer-readable storage medium is provided, on which a program is stored. The stored program includes a dual-vehicle linkage control method in any of the above embodiments that can be loaded by a processor and processed.

[0176] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0177] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A dual-vehicle linkage control method in which a laser radar is arranged at the rear end of a front vehicle, which is applied to a front and rear dual-vehicle linkage system, characterized in that: The front and rear dual-vehicle linkage system includes a front vehicle and a rear vehicle in the traveling direction; wherein a laser radar is provided at the rear end of the front vehicle and left and right reflectors are provided at the front end of the rear vehicle; the method includes: Based on the laser radar, the left and right reflectors are identified and the relative positions of the front and rear vehicles are calculated; The dual-vehicle linkage control parameter calculation is performed based on the relative position information and the linkage control instruction, including: In the non-rotating translation mode of the front and rear vehicles, that is, controlling the angular velocity In the case of , the dual-vehicle linkage control parameter calculation includes: Get the speed in the same direction as the vehicle head and the speed perpendicular to the vehicle head; Based on the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction, calculating the translation speed and translation angle in the translation mode; Based on the translation speed, the speeds of the front, rear, left, and right wheels of the front vehicle and the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained; based on the translation angle, the steering wheel deflection angles of the front, rear, left, and right wheels of the front vehicle and the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle are obtained; In the non-translational rotation mode of the front and rear vehicles, that is, controlling the angular velocity In the case of , the dual-vehicle linkage control parameter calculation includes: Get the wheelbase and track width of the front and rear vehicles; Calculate the distance between the two vehicles based on the information of the relative positions of the front and rear vehicles; Based on the wheelbase, track width and distance between the front and rear vehicles, the turning radius and steering wheel deflection angle of the front vehicle's front, rear, left and right wheels are calculated, and the turning radius and steering wheel deflection angle of the rear vehicle's front, rear, left and right wheels are calculated; Based on the control angular velocity and the rotation radius of the front vehicle's front, rear, left, and right wheels, the speed of the front vehicle's front, rear, left, and right wheels is calculated; based on the control angular velocity and the rotation radius of the front, rear, left, and right wheels of the rear vehicle's front, rear, left, and right wheels, the speed of the rear vehicle's front, rear, left, and right wheels is calculated; Perform double-vehicle linkage control based on the calculated double-vehicle linkage control parameters; The method of identifying the left and right reflectors based on the laser radar and calculating the relative positions of the front and rear vehicles includes: Calculate the coordinates of the center points of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, and the angle of the vertical line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system; Based on the coordinates of the center points of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system and the angle of the perpendicular line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, the coordinates and angles of the control center point of the rear vehicle in the control center coordinate system of the front vehicle are calculated; Based on the coordinates and angles of the rear vehicle control center point in the front vehicle control center coordinate system, the coordinates and orientation of the front vehicle control center coordinate system in the rear vehicle control center coordinate system are obtained; The coordinates and orientation of the front vehicle control center coordinate system in the rear vehicle control center coordinate system are used as the relative positions of the front and rear vehicles.

2. The dual-vehicle linkage control method according to claim 1, characterized in that: The calculation of the coordinates of the center points of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system and the angle of the vertical line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system includes: ， ， ， in, It indicates the x-coordinate of the center point of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system. Indicates the y coordinate of the center point of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system, It indicates the angle of the vertical line connecting the left and right reflectors at the front end of the rear vehicle in the radar coordinate system. It represents the x-coordinate of the left reflector at the front end of the rear vehicle in the radar coordinate system. Indicates the y coordinate of the left reflector at the front end of the rear vehicle in the radar coordinate system, It represents the x-coordinate of the right reflector at the front end of the rear vehicle in the radar coordinate system. Indicates the y coordinate of the right reflector at the front end of the rear vehicle in the radar coordinate system; The calculation of the coordinates and angle of the control center point of the rear vehicle in the control center coordinate system of the front vehicle based on the coordinates of the center points of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system and the angle of the perpendicular direction of the connecting line of the left and right reflectors at the front end of the rear vehicle in the radar coordinate system includes: ， ， in, , and They represent the x-coordinate, y-coordinate and angle of the rear vehicle control center point in the front vehicle control center coordinate system. and They represent the x-coordinate and y-coordinate of the rear vehicle control center point in the symmetrical center coordinate system of the left and right reflectors, respectively. They can be obtained based on the mechanical parameters. , and They represent the x-coordinate, y-coordinate and angle of the laser radar under the control center of the preceding vehicle, respectively, and can be obtained according to the mechanical parameters; Among them, the direction of the symmetric center coordinate system of the left and right reflectors is perpendicular to the line connecting the left and right reflectors, and the vertical left is the positive direction of the y-axis. The control center coordinate system of the rear vehicle has the same direction as the symmetric center coordinate system of the left and right reflectors. When the front and rear vehicles are aligned front and back, the symmetric center coordinate system of the left and right reflectors has the same direction as the radar coordinate system, and the control center coordinate system of the front vehicle has the same direction as the radar coordinate system; The obtaining of the coordinates and orientation of the front vehicle control center coordinate system in the rear vehicle control center coordinate system based on the coordinates and angles of the rear vehicle control center point in the front vehicle control center coordinate system includes: ， in, , and They respectively represent the x-coordinate, y-coordinate and direction of the front vehicle control center coordinate system in the rear vehicle control center coordinate system.

3. The dual-vehicle linkage control method according to claim 1, characterized in that: The calculation of the translation speed and the translation angle in the translation mode based on the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction includes: ， ， in, and Respectively represent the translation speed and translation angle in translation mode, and They respectively represent the speed in the same direction as the vehicle head direction and the speed perpendicular to the vehicle head direction in the remote control command; The obtaining of the speeds of the front, rear, left, and right four wheels of the front vehicle and the speeds of the front, rear, left, and right four wheels of the rear vehicle based on the translation speed, and the obtaining of the steering wheel deflection angles of the front, rear, left, and right four wheels of the front vehicle and the steering wheel deflection angles of the front, rear, left, and right four wheels of the rear vehicle based on the translation angle, include: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， in, Indicates the front right wheel speed of the vehicle in front. Indicates the front left wheel speed of the vehicle ahead. Indicates the speed of the rear right wheel of the front vehicle. Indicates the speed of the rear left wheel of the front vehicle. Indicates the speed of the front right wheel of the rear vehicle. Indicates the speed of the front left wheel of the rear vehicle. Indicates the speed of the rear right wheel of the following vehicle. Indicates the speed of the rear left wheel of the following vehicle. Indicates the steering wheel deflection angle of the front right wheel of the front vehicle. Indicates the steering wheel deflection angle of the front left wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the front vehicle. Indicates the steering wheel deflection angle of the front right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the front left wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the following vehicle.

4. The dual-vehicle linkage control method according to claim 1, characterized in that: The method of calculating the rotation radius and steering wheel deflection angle of the front vehicle's front, rear, left, and right wheels and the steering wheel deflection angle of the rear vehicle's front, rear, left, and right wheels based on the wheelbase and track of the front and rear vehicles and the distance between the two vehicles includes: ， ， ， ， in, Indicates wheelbase, Indicates wheelbase, Indicates the distance between two vehicles. The wheelbase and track width of the front and rear vehicles are the same; Indicates the turning radius of the front right wheel of the front vehicle. Indicates the turning radius of the front left wheel of the front vehicle. Indicates the rotation radius of the rear right wheel of the front vehicle. Indicates the rotation radius of the rear left wheel of the front vehicle. Indicates the rotation radius of the front right wheel of the rear vehicle. Indicates the turning radius of the front left wheel of the rear vehicle. Indicates the rotation radius of the rear right wheel of the following vehicle. Indicates the rotation radius of the rear left wheel of the following vehicle. Indicates the steering wheel deflection angle of the front right wheel of the front vehicle. Indicates the steering wheel deflection angle of the front left wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the front vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the front vehicle. Indicates the steering wheel deflection angle of the front right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the front left wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the following vehicle; The method of calculating the speed of the front vehicle's front, rear, left, and right wheels based on the control angular velocity and the rotation radius of the front vehicle's front, rear, left, and right wheels; and calculating the speed of the rear vehicle's front, rear, left, and right wheels based on the control angular velocity and the rotation radius of the rear vehicle's front, rear, left, and right wheels include: ， ， ， ， ， ， ， ， in, Indicates the front right wheel speed of the vehicle in front. Indicates the front left wheel speed of the vehicle ahead. Indicates the speed of the rear right wheel of the front vehicle. Indicates the speed of the rear left wheel of the front vehicle. Indicates the speed of the front right wheel of the rear vehicle. Indicates the speed of the front left wheel of the rear vehicle. Indicates the speed of the rear right wheel of the following vehicle. Indicates the speed of the rear left wheel of the following vehicle.

5. The dual-vehicle linkage control method according to claim 1, characterized in that: The method of calculating the dual-vehicle linkage control parameters based on the relative position information and the linkage control instruction further includes: Get the desired x-coordinate, y-coordinate and angle of the rear vehicle control center point in the front vehicle control center coordinate system, as well as the current x-coordinate, y-coordinate and angle; Calculate the relative x coordinate, relative y coordinate and relative angle of the x coordinate, y coordinate and angle you want to keep relative to the current x coordinate, y coordinate and angle; In the translation mode where the front and rear vehicles are non-rotating: If the forward direction of the vehicle body belongs to the X deviation zone, the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation speed and the relative X coordinate, and the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation angle and the relative angle; If the forward direction of the vehicle body belongs to the Y deviation zone, the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation speed and the relative Y coordinate, and the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation angle and the relative angle; In the rotation mode where the front and rear vehicles are non-translational: Based on the current rotation radius, control angular velocity and the relative angle, the steering wheel speed of the following vehicle is calculated.

6. The dual-vehicle linkage control method according to claim 5, characterized in that: The obtaining of the x-coordinate, y-coordinate and angle that the rear vehicle control center point is expected to maintain in the front vehicle control center coordinate system includes: ， ， ， in, Indicates wheelbase, Indicates the distance between two cars, the wheelbase of the front and rear cars is the same; , and They respectively represent the x-coordinate, y-coordinate and angle that the rear vehicle control center point is expected to maintain in the front vehicle control center coordinate system; The calculation of the relative x coordinate, relative y coordinate and relative angle of the x coordinate, y coordinate and angle expected to be maintained relative to the current x coordinate, y coordinate and angle includes: ， ， in, , and Respectively represent the current x-coordinate, y-coordinate and angle, , and They represent the relative x-coordinate, relative y-coordinate, and relative angle respectively.

7. The dual-vehicle linkage control method according to claim 5, characterized in that: If the forward direction of the vehicle body belongs to the X deviation zone, the speeds of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation speed and the relative X coordinate, and the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle are obtained based on the translation angle and the relative angle, including: If the vehicle is moving in the direction , then the forward direction Belonging to the X deviation partition; the method of obtaining the speeds of the front, rear, left, and right wheels of the rear vehicle based on the translation speed and the relative X coordinate, and obtaining the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle based on the translation angle and the relative angle includes: ， ， ， ， ， ， ， ， in, Indicates the translation speed in translation mode. and Represent the relative x coordinate and relative angle respectively, Represents the error correction coefficient, which is determined according to the speed of error correction. Indicates the speed of the front right wheel of the rear vehicle. Indicates the speed of the front left wheel of the rear vehicle. Indicates the speed of the rear right wheel of the following vehicle. Indicates the speed of the rear left wheel of the following vehicle. Indicates the steering wheel deflection angle of the front right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the front left wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear right wheel of the rear vehicle. Indicates the steering wheel deflection angle of the rear left wheel of the following vehicle. Indicates the translation angle in translation mode; If the vehicle is moving in the direction , then the forward direction Belonging to the Y deviation partition; the method of obtaining the speeds of the front, rear, left, and right wheels of the rear vehicle based on the translation speed and the relative Y coordinate, and obtaining the steering wheel deflection angles of the front, rear, left, and right wheels of the rear vehicle based on the translation angle and the relative angle includes: ， ， ， ， ， ， ， ， in, Represents the relative y coordinate; The calculation of the steering wheel speed of the following vehicle based on the current rotation radius, the control angular velocity and the relative angle includes: ， ， ， ， in, Indicates the rotation radius of the front right wheel of the rear vehicle. Indicates the turning radius of the front left wheel of the rear vehicle. Indicates the rotation radius of the rear right wheel of the following vehicle. Indicates the turning radius of the rear left wheel of the following vehicle.

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