Forklift motion control method and device and storage medium

Abstract

The invention discloses a forklift movement control method and device and a storage medium, and relates to the technical field of forklift control, and the forklift movement control method comprises the steps that the adjustable distance of a forklift and the current position of the center of a rear axle of the forklift are determined; the position of the forklift is repeatedly adjusted within the adjustable distance with the corresponding current position as the starting point till the center of a rear axle of the forklift is adjusted to the Y axis of a preset coordinate system, and the preset coordinate system is constructed with the center point of the tray as the original point; the heading of the forklift is adjusted to be parallel to the Y axis of the preset coordinate system; and the steering angle of the forklift is rotated to 0 degree, so that the forklift is controlled to advance until a pallet fork of the forklift is inserted into the insertion hole of the tray. The center of the rear axle of the forklift is adjusted to the Y axis of the preset coordinate system, the heading of the forklift is adjusted to be parallel to the Y axis, so that the forklift is right opposite to the position of the tray, the steering angle of the forklift is set to be 0 degree, it can be guaranteed that the heading of the forklift is basically unchanged, and then it is guaranteed that a pallet fork of the forklift is accurately aligned and inserted into an insertion hole of the tray.

Description

Technical Field

[0001] This application relates to the field of forklift control technology, and in particular to a forklift motion control method, device and storage medium. Background Technology

[0002] Unmanned forklifts can automatically identify the position and angle of pallets using sensors such as LiDAR and vision cameras, and then autonomously adjust their own position and posture to insert the forks into the pallet slots. Currently, alignment solutions mostly use Reeds-Shepp (RS) curves to plan the path, combined with tracking algorithms to control the forklift to travel along the curve. However, in short-distance adjustment scenarios, due to the short adjustment distance, the tracking algorithm has difficulty accurately following the planned path, resulting in the forklift's forks failing to accurately align with the pallet slots. Summary of the Invention

[0003] The main objective of this application is to provide a forklift motion control method, device, and storage medium, which aims to ensure that the forklift forks are accurately aligned and inserted into the pallet slots.

[0004] To achieve the above objectives, this application proposes a forklift motion control method, the method comprising: Determine the adjustable distance of the forklift and the current position of the rear axle center of the forklift; Starting from the current position, the position of the rear axle center of the forklift is repeatedly adjusted within the adjustable distance until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin. Adjust the forklift's heading to be parallel to the Y-axis of the preset coordinate system; The forklift's steering angle is rotated to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the pallet's slots.

[0005] In one embodiment, the step of repeatedly adjusting the position of the rear axle center of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system, includes: Starting from the current position, the forklift is controlled to move forward a preset distance according to the preset target forward steering parameters, wherein the preset distance does not exceed the adjustable distance; After the forklift has traveled a preset distance, it is controlled to retreat to the target baseline according to the preset target reverse steering parameters. The target baseline is a straight line that passes through the current position and is parallel to the X-axis of the preset coordinate system. Repeat the above forward and backward operations until the rear axle center of the forklift is aligned with the Y-axis of the preset coordinate system.

[0006] In one embodiment, the target forward steering parameters include a first forward steering parameter and a second forward steering parameter; the first forward steering parameter and the second forward steering parameter correspond to different steering directions; The step of controlling the forklift to move a preset distance based on the current position and preset target forward steering parameters includes: Starting from the current position, the forklift is controlled to move forward a first distance according to the first forward steering parameters; After the forklift has traveled a first distance, it is controlled to travel a second distance according to the second forward steering parameter, wherein the sum of the first distance and the second distance is equal to the preset distance.

[0007] In one embodiment, the first distance includes a target forward sub-distance and a steering buffer distance; the step of controlling the forklift to advance a second distance according to the second forward steering parameters after the forklift has advanced the first distance includes: After the forklift has advanced the target forward sub-distance according to the first forward steering parameter, the forklift is controlled to start a steering switch, wherein when the forklift has turned and moved the steering buffer distance, the actual steering parameter of the forklift reaches the second forward steering parameter; The forklift is controlled to move forward a second distance according to the second forward steering parameter.

[0008] In one embodiment, controlling the forklift to travel a second distance according to the second forward steering parameter includes: Determine the forklift's deviation angle and wheelbase, wherein the deviation angle refers to the magnitude of the deviation from the forklift's initial angle, and the forklift's initial angle refers to the forklift's heading angle when the adjustment begins; The correction angle is calculated based on the deviation angle, the vehicle wheelbase, and the second distance; The second forward steering parameter is corrected according to the correction angle, so that the forklift can be controlled to move forward a second distance according to the corrected second forward steering parameter.

[0009] In one embodiment, the target reverse steering parameters include a first reverse steering parameter and a second reverse steering parameter; the first reverse steering parameter and the second reverse steering parameter correspond to different steering directions; The step of controlling the forklift to reverse to the target baseline according to preset target reversing steering parameters after the forklift has traveled a preset forward distance includes: After the forklift has traveled a preset distance forward, the forklift is controlled to reverse a preset first distance according to the first reverse steering parameter; After the forklift has reversed a first distance, the forklift is controlled to reverse to the target baseline according to the second reverse steering parameter.

[0010] In one embodiment, repeating the above forward and backward operations until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system includes: During each forward or backward movement, determine the target distance between the current position of the rear axis center and the Y-axis; When the target distance reaches the preset error requirement, the rear axle center of the forklift is adjusted to the Y-axis.

[0011] In one embodiment, adjusting the forklift's heading to be parallel to the Y-axis of the preset coordinate system includes: The forklift is controlled to move forward or backward according to a preset steering angle, so as to adjust the forklift's heading to be parallel to the Y-axis of the preset coordinate system.

[0012] Furthermore, to achieve the above objectives, this application also proposes a forklift motion control device, which includes: The determination module is used to determine the adjustable distance of the forklift and the current position of the rear axle center of the forklift; The rear axle center adjustment module is used to repeatedly adjust the position of the rear axle center of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin. A heading adjustment module is used to adjust the heading of the forklift to be parallel to the Y-axis of the preset coordinate system; The control module is used to rotate the steering angle of the forklift to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the slots of the pallet.

[0013] In addition, to achieve the above objectives, this application also proposes a forklift motion control device, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the forklift motion control method as described above.

[0014] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the forklift motion control method described above.

[0015] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the forklift motion control method described above.

[0016] This application provides a forklift motion control method, device, and storage medium. The forklift motion control method includes: determining the adjustable distance of the forklift and the current position of the rear axle center of the forklift; repeatedly adjusting the position of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin; adjusting the heading of the forklift to be parallel to the Y-axis of the preset coordinate system; and rotating the steering angle of the forklift to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the pallet's insertion holes. By repeatedly adjusting the position of the forklift within the adjustable distance to adjust the rear axle center of the forklift to the Y-axis of the preset coordinate system, and then adjusting the heading of the forklift to be parallel to the Y-axis, the forklift and pallet are aligned. Furthermore, setting the steering angle of the forklift to 0 degrees ensures that the forklift's heading remains essentially unchanged, thereby ensuring that the forklift's forks are accurately aligned and inserted into the pallet's insertion holes. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating an embodiment of the forklift motion control method of this application. Figure 2 This is one of the schematic diagrams provided in an embodiment of the present application for adjusting the center of the rear axle of a forklift; Figure 3 This is a second schematic diagram of adjusting the rear axle center of a forklift according to an embodiment of this application; Figure 4 This is a flowchart illustrating Embodiment 2 of the forklift motion control method of this application. Figure 5 This is a flowchart illustrating Embodiment 3 of the forklift motion control method of this application. Figure 6This is a flowchart illustrating Embodiment 4 of the forklift motion control method of this application. Figure 7 This is a schematic diagram of the module structure of the forklift motion control device according to an embodiment of this application; Figure 8 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the forklift motion control method in the embodiments of this application.

[0020] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0022] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0023] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device, big data service platform, or forklift motion control system capable of the above functions. The following description uses a forklift motion control system as an example to illustrate this embodiment and the subsequent embodiments.

[0024] Based on this, the embodiments of this application provide a forklift motion control method, referring to... Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of the forklift motion control method of this application.

[0025] Step S11: Determine the adjustable distance of the forklift and the current position of the rear axle center of the forklift; It should be noted that the rear axle center of the forklift refers to the geometric center point corresponding to the line connecting the centers of the two drive wheels on the rear axle. A preset coordinate system is constructed in advance, with the center point of the pallet as the origin, east as the positive X-axis, and north as the positive Y-axis. The current coordinates of the rear axle center within this preset coordinate system are then determined to represent the current position.

[0026] In one embodiment, the adjustable distance of the forklift can be determined based on the distance between the current position of the rear axle center of the forklift and the pallet. Optionally, it is necessary to exclude collision risk areas and finally determine the adjustable range from the current position to the safe area near the pallet.

[0027] Step S12: Starting from the current position, repeatedly adjust the position of the forklift within the adjustable distance until the center of the rear axle of the forklift is adjusted to the Y-axis of the preset coordinate system. It should be noted that the adjustment is based on the rear axle center of the forklift, with the goal of adjusting the rear axle center until it falls on the Y-axis of the preset coordinate system after several adjustments. In this embodiment, the adjustment has two directions: forward and backward. First, starting from the current position of the rear axle center, the forklift is controlled to move forward a preset distance according to the preset target forward steering parameters. At this point, the forward direction adjustment is complete. After the forklift has moved forward the preset distance, the forklift is controlled to move backward to the target baseline according to the preset target backward steering parameters. The backward direction adjustment is complete. The target baseline is a straight line passing through the starting point and parallel to the X-axis of the preset coordinate system. This forward and backward adjustment operation is repeated. In each cycle, the rear axle center of the forklift moves closer to the Y-axis until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system. It should be noted that the target forward and backward steering parameters include steering angle and steering direction. The specific adjustment process is described in detail in the following embodiments and will not be repeated here.

[0028] Step S13: Adjust the heading of the forklift to be parallel to the Y-axis of the preset coordinate system; It's important to note that, according to the kinematics of a forklift, its center of rotation always lies on the line connecting the two rear wheels. If the forklift's front tires rotate 90°, the center of rotation becomes the rear axle center. At this point, driving the forklift will adjust its heading, but will not move the rear axle center. In other words, when the forklift's turning angle reaches 90°, the center of rotation is the rear axle center. Applying driving force forward or backward will not cause the rear axle center to shift laterally, achieving the control effect of adjusting only the heading without changing the lateral position.

[0029] In this embodiment, the forklift is controlled to move forward or backward according to a preset steering angle, so as to adjust the heading of the forklift to be parallel to the Y-axis of the preset coordinate system, wherein the preset steering angle is set to 90°.

[0030] Step S14: Rotate the steering angle of the forklift to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the slots of the pallet.

[0031] It should be noted that when the forklift's rear axle center is on the Y-axis and the forklift's heading is parallel to the Y-axis, it indicates that the forklift and pallet are aligned. At this point, the forklift's steering angle is set to 0 degrees, and the forklift is controlled to move forward until its forks are inserted into the pallet's insertion holes. Because the forklift is close to the pallet, the forklift's heading remains essentially unchanged during insertion, thus ensuring that the forklift's forks are accurately aligned and inserted into the pallet's insertion holes.

[0032] This embodiment, through the above-described scheme, includes: determining the adjustable distance of the forklift and the current position of the rear axle center of the forklift; repeatedly adjusting the position of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin; adjusting the heading of the forklift to be parallel to the Y-axis of the preset coordinate system; rotating the steering angle of the forklift to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the pallet's insertion holes. By repeatedly adjusting the position of the forklift within the adjustable distance to adjust the rear axle center of the forklift to the Y-axis of the preset coordinate system, and then adjusting the heading of the forklift to be parallel to the Y-axis of the pallet, so that the forklift and pallet are directly aligned, and further, setting the steering angle of the forklift to 0 degrees ensures that the forklift's heading remains basically unchanged, thereby ensuring that the forklift's forks are accurately aligned and inserted into the pallet's insertion holes.

[0033] In one feasible implementation, starting from the current position, the position of the rear axle center of the forklift is repeatedly adjusted within the adjustable distance until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system, including: Step S21: Starting from the current position, control the forklift to move forward a preset distance according to the preset target forward steering parameters, wherein the preset distance does not exceed the adjustable distance; It should be noted that, referring to Figure 2 , Figure 2 This is one of the schematic diagrams for adjusting the center of the rear axle of a forklift according to an embodiment of this application. L1 is a target baseline, which is a straight line passing through the current position and parallel to the X-axis of the preset coordinate system. The distance between L1 and L3 is the adjustable distance in this embodiment.

[0034] In addition, there are two directions for adjustment: forward and reverse. Taking the forward direction as an example, the adjustable distance is divided into two segments. The first segment turns in the direction that reduces lateral error, and the second segment turns in the opposite direction. Optionally, refer to... Figure 2 L2 is the center line of L1 and L3, and the adjustable distance between L1 and L3 is divided into two equal segments.

[0035] In one embodiment, the target forward steering parameters include a first forward steering parameter and a second forward steering parameter. Optionally, the steering angles in the first and second forward steering parameters are the same in magnitude but opposite in direction. Specifically, starting from the current position, the forklift is controlled to advance a first distance according to the steering angle and direction in the first forward steering parameter. Further, after the forklift has advanced the first distance, the forklift is controlled to advance a second distance according to the steering angle and direction in the second forward steering parameter, wherein the sum of the first and second distances is equal to the preset distance. In other embodiments, depending on the forklift's heading, the forklift advances with different steering angles in the first and second distance stages, thereby achieving the control effect of adjusting both lateral and heading simultaneously.

[0036] As a concrete example, refer to Figure 2 Starting from point P2 (in the forward direction), the forklift's rear axle center first turns left by a certain angle. When it reaches line L2, the turning angle remains unchanged, then it switches to the opposite turning angle and reaches point P4. At this point, the forward direction adjustment is complete.

[0037] Step S22: After the forklift has traveled a preset distance forward, control the forklift to retreat to the target baseline according to the preset target reverse steering parameters; In this embodiment, the target reverse steering parameters include a first reverse steering parameter and a second reverse steering parameter; optionally, the steering angle in the first reverse steering parameter and the steering angle in the second reverse steering parameter are the same in magnitude but opposite in direction. Specifically, after the forklift has traveled a preset distance forward, the forklift is controlled to reverse a preset first distance according to the steering angle and steering direction in the first reverse steering parameter; after the forklift has reversed the first distance, the forklift is controlled to reverse to the target baseline according to the steering angle and steering direction in the second reverse steering parameter.

[0038] As a concrete example, refer to Figure 2 After the forklift's rear axle center moves forward to point P4, it starts moving backward from point P4 again. First, it turns left by a certain angle, and when it reaches line L2, the steering angle remains the same. Then, it switches to the opposite steering angle for the second half of the movement, reaching point P3. At this point, the backward adjustment is complete. This process is repeated, and with each cycle, the forklift's rear axle center moves closer to the Y-axis until it lands on the Y-axis.

[0039] Furthermore, in other embodiments, reference is made to Figure 3 , Figure 3The second schematic diagram of adjusting the rear axle center of the forklift provided in one embodiment of this application no longer uses L2 as the steering reference point, but instead moves to one side according to the forklift's heading. This can achieve the control effect of adjusting the lateral direction and the heading at the same time. For example, the forward direction uses L4 as the steering reference point, and the reverse direction uses L5 as the steering reference point.

[0040] Step S23: Repeat the above forward and backward operations until the center of the rear axle of the forklift is adjusted to the Y-axis of the preset coordinate system.

[0041] In this embodiment, regardless of whether it is the forward or backward direction, the distance of movement in the first half is the same as that in the second half, but the directions are opposite. At this time, the final heading angle after adjustment remains unchanged, while the lateral movement is a certain distance. By repeating the above forward and backward operations, the rear axle center of the forklift can be adjusted to the Y-axis of the preset coordinate system.

[0042] This embodiment controls the forklift to advance a preset distance from the current position according to preset target forward steering parameters. After advancing the forklift a preset distance, the forklift is controlled to retreat to the target baseline according to preset target reverse steering parameters. This forward and reverse operation is repeated until the rear axle center of the forklift is aligned with the Y-axis of a preset coordinate system. By aligning the rear axle center of the forklift with the Y-axis of the preset coordinate system, the forklift's heading is subsequently adjusted to be parallel to the Y-axis, ensuring that the forklift and pallet are directly aligned and that the forklift's forks are precisely aligned and inserted into the pallet's insertion holes.

[0043] In one feasible implementation, refer to Figure 4 , Figure 4 This is a flowchart illustrating a second embodiment of the forklift motion control method of this application; starting from the current position, the forklift is controlled to move forward a preset distance according to preset target forward steering parameters, including: Step S31: Starting from the current position, control the forklift to move forward a first distance according to the first forward steering parameter; Step S32: After the forklift has traveled a first distance, control the forklift to travel a second distance according to the second forward steering parameter.

[0044] In this embodiment, starting from the current position, the forklift is controlled to move forward a first distance according to the steering angle and steering direction in the first forward steering parameters. Optionally, it can be referenced... Figure 2 The first distance is the distance between L1 and L2. Further, after the forklift has traveled the first distance, it is controlled to travel a second distance according to the steering angle and steering direction in the second forward steering parameters, wherein the sum of the first distance and the second distance is equal to the preset distance.

[0045] In other embodiments, since the forward or backward movement is theoretically composed of two arcs joined together, and there is a sudden change in curvature between the two arcs, there will be a sudden change in direction. However, in reality, switching from one direction to the opposite direction takes time, resulting in heading drift, which gradually deviates from the initial heading. Therefore, in the first half of the forward movement (e.g., Figure 2 A preset steering buffer distance is reserved between L1 and centerline L2, wherein the steering buffer distance is determined based on communication delay, steering rate, and steering change value. That is, the first distance is divided into a target forward sub-distance and a steering buffer distance. After the forklift advances the target forward sub-distance according to the first forward steering parameters, the forklift is controlled to begin steering switching. When the forklift turns and moves the steering buffer distance, that is, after passing the steering buffer distance and reaching line L2, it is ensured that the actual steering parameters of the forklift reach the second forward steering parameters; that is, at the end of the first distance, the forklift's actual steering reaches the second steering parameters. More specifically, the steering angle at this time is equal in value to the steering angle corresponding to the first forward distance stage, but the steering direction is opposite. Further, according to the second forward steering parameters, the forklift is controlled to advance a second distance, wherein the sum of the first distance and the second distance is equal to the preset distance.

[0046] This embodiment starts from the current position and controls the forklift to move forward a first distance according to the first forward steering parameter. After the forklift has moved the first distance, the forklift is controlled to start turning. When the forklift moves a preset steering buffer distance, the steering parameter of the forklift is adjusted to the second forward steering parameter. According to the second forward steering parameter, the forklift is controlled to move forward a second distance to adjust the rear axle center of the forklift to the Y-axis of the preset coordinate system. Subsequently, the heading of the forklift is adjusted to be parallel to the Y-axis so that the forklift is directly aligned with the pallet and the forklift forks are accurately aligned and inserted into the pallet's insertion holes.

[0047] In one feasible implementation, refer to Figure 5 , Figure 5 This is a flowchart illustrating a third embodiment of the forklift motion control method of this application; controlling the forklift to move forward a second distance according to the second forward steering parameter includes: Step S41: Determine the deviation angle of the forklift and the wheelbase of the vehicle, wherein the deviation angle refers to the magnitude of the deviation from the initial angle of the forklift, and the initial angle of the forklift refers to the heading angle of the forklift when the adjustment begins; Step S42: Calculate the correction angle based on the deviation angle, the vehicle wheelbase, and the second distance; Step S43: Correct the second forward steering parameter according to the correction angle, so as to control the forklift to move forward a second distance according to the corrected second forward steering parameter.

[0048] It should be noted that the deviation angle refers to the magnitude of the deviation from the forklift's initial angle, which refers to the forklift's heading angle when the adjustment begins. Each time the forklift reaches the L2 line, the angle of deviation from the initial heading will be slightly different, and the steering parameters at this time need to be adjusted to ensure that it remains basically equal to the initial heading.

[0049] In this embodiment, after adjusting the forklift's steering parameters to the second forward steering parameters, the forklift's deviation angle and wheelbase are determined; the wheelbase refers to the straight-line distance between the center of the forklift's front axle and the center of its rear axle; a correction angle is calculated based on the deviation angle, the wheelbase, and the second distance; wherein, the formula for calculating the correction angle is as follows:

[0050] in, Indicates the forklift's deviation angle. This indicates the wheelbase of the forklift. Indicates the second distance.

[0051] Furthermore, the steering angle in the second forward steering parameter is corrected according to the correction angle, so as to control the forklift to move forward a second distance according to the corrected second forward steering parameter.

[0052] This embodiment calculates a correction angle; then, according to the correction angle, it corrects the second forward steering parameter, so as to control the forklift to move forward a second distance according to the corrected second forward steering parameter, effectively reducing heading drift and improving the accuracy of the forklift's rear axle center adjustment.

[0053] In one feasible implementation, refer to Figure 6 , Figure 6 This is a flowchart illustrating Embodiment 4 of the forklift motion control method of this application; after the forklift has traveled a preset forward distance, the forklift is controlled to retreat to the target baseline according to preset target reverse steering parameters, including: Step S51: After the forklift has moved forward a preset distance, control the forklift to move backward a preset first distance according to the first reverse steering parameter; Step S52: After the forklift has reversed a first distance, control the forklift to reverse to the target baseline according to the second reverse steering parameter.

[0054] In this embodiment, after the forklift has traveled a preset distance, the forklift is controlled to travel a first distance according to the steering angle and steering direction in the first reverse steering parameters. Optionally, this can be referenced. Figure 2 The first distance is the distance between L3 and L2. Further, after the forklift has reversed the first distance, the forklift is controlled to reverse to the target baseline according to the steering angle and steering direction in the second reverse steering parameters.

[0055] In other embodiments, in the first half of the backward movement (e.g., Figure 2 The distance between L3 and centerline L2 is used to reserve a steering buffer distance. That is, during the reversing process, the first distance is divided into a target reversing sub-distance and a steering buffer distance. After the forklift reverses the target reversing sub-distance according to the first reversing steering parameters, the forklift is controlled to begin steering switching. When the forklift moves the steering buffer distance, that is, after passing the steering buffer distance and reaching line L2, the forklift's actual steering parameters reach the second reversing steering parameters. This ensures that the forklift's actual steering reaches the second steering parameters at the end of the first distance. More specifically, the steering angle at this time is equal in value to the steering angle corresponding to the stage of the target forward sub-distance, but in the opposite direction. Therefore, according to the second reversing steering parameters, the forklift is controlled to continue reversing. It should be noted that the process of controlling the forklift to reverse is basically the same as the above-described forward process.

[0056] In other embodiments, a correction angle can also be calculated to correct the steering angle in the second reverse steering parameters, so as to control the forklift to reverse according to the corrected second reverse steering parameters. The angle correction process is specifically described in the above embodiments and will not be repeated here.

[0057] In this embodiment, after the forklift has moved forward a preset distance, the forklift is controlled to move backward a preset first distance according to the first reverse steering parameter; after the forklift has moved backward a first distance, the forklift is controlled to move backward to the target baseline according to the second reverse steering parameter, so as to adjust the center of the rear axle of the forklift to the Y-axis of the preset coordinate system. Subsequently, the heading of the forklift is adjusted to be parallel to the Y-axis so that the forklift and the pallet are aligned, ensuring that the forklift forks are accurately aligned and inserted into the holes of the pallet.

[0058] In one feasible implementation, the above forward and backward operations are repeated until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system, including: Step S61: During each forward or backward movement, determine the target distance between the current position of the rear axle center and the Y-axis; Step S62: When the target distance reaches the preset error requirement, determine that the rear axle center of the forklift is adjusted to the Y-axis.

[0059] In this embodiment, during each forward or backward movement, the target distance between the current position of the rear axle center and the Y-axis is determined. Optionally, the forklift is equipped with a sensor to detect the target distance in real time during the adjustment process. When the target distance reaches a preset error requirement, it is determined that the rear axle center of the forklift has been adjusted to the Y-axis. Optionally, the preset error requirement can be set according to actual conditions. In a specific example, the standard for measuring whether it has been adjusted to the Y-axis is whether the error on the X-axis is close to 0.

[0060] Furthermore, the turning radius of the forklift at the corresponding turning angle can be determined based on the turning angle in the target forward turning parameters or the turning angle in the target reverse turning parameters. Further, the lateral distance traveled by the forklift is calculated based on the turning radius and the adjustable distance, wherein the formula for calculating the lateral distance is as follows:

[0061] Among them, L d R represents the lateral distance, and L represents the turning radius. When the adjustable distance is divided into two equal segments, L represents half of the adjustable distance.

[0062] Furthermore, the adjustment cycle for the forklift to move forward or backward can be initially determined based on the lateral distance.

[0063] This embodiment determines the target distance between the current position of the rear axle center and the Y-axis, and then calculates the lateral distance the forklift moves based on the target forward steering parameters or the target backward steering parameters. Furthermore, based on the lateral distance and the target distance, it determines whether the rear axle center of the forklift is adjusted to the Y-axis, ensuring that the forklift forks are accurately aligned with the insertion holes into the pallet.

[0064] It should be noted that the examples in the figure are only for understanding this application and do not constitute a limitation on the forklift motion control method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0065] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0066] This application also provides a forklift motion control device; please refer to [reference needed]. Figure 7 , Figure 7This is a schematic diagram of the module structure of the forklift motion control device according to an embodiment of this application; the forklift motion control device includes: The determining module 71 is used to determine the adjustable distance of the forklift and the current position of the rear axle center of the forklift; The rear axle center adjustment module 72 is used to repeatedly adjust the position of the rear axle center of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin. The heading adjustment module 73 is used to adjust the heading of the forklift to be parallel to the Y-axis of the preset coordinate system; The control module 74 is used to rotate the steering angle of the forklift to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the slots of the pallet.

[0067] The rear axle center adjustment module 72 is also used for: Starting from the current position, the forklift is controlled to move forward a preset distance according to the preset target forward steering parameters, wherein the preset distance does not exceed the adjustable distance; After the forklift has traveled a preset distance, it is controlled to retreat to the target baseline according to the preset target reverse steering parameters. The target baseline is a straight line that passes through the current position and is parallel to the X-axis of the preset coordinate system. Repeat the above forward and backward operations until the rear axle center of the forklift is aligned with the Y-axis of the preset coordinate system.

[0068] The rear axle center adjustment module 72 is also used for: Starting from the current position, the forklift is controlled to move forward a first distance according to the first forward steering parameters; After the forklift has traveled a first distance, it is controlled to travel a second distance according to the second forward steering parameter, wherein the sum of the first distance and the second distance is equal to the preset distance.

[0069] The rear axle center adjustment module 72 is also used for: After the forklift has advanced the target forward sub-distance according to the first forward steering parameter, the forklift is controlled to start a steering switch, wherein when the forklift has turned and moved the steering buffer distance, the actual steering parameter of the forklift reaches the second forward steering parameter; The forklift is controlled to move forward a second distance according to the second forward steering parameter.

[0070] The rear axle center adjustment module 72 is also used for: Determine the forklift's deviation angle and wheelbase, wherein the deviation angle refers to the magnitude of the deviation from the forklift's initial angle, and the forklift's initial angle refers to the forklift's heading angle when the adjustment begins; The correction angle is calculated based on the deviation angle, the vehicle wheelbase, and the second distance; The second forward steering parameter is corrected according to the correction angle, so that the forklift can be controlled to move forward a second distance according to the corrected second forward steering parameter.

[0071] The rear axle center adjustment module 72 is also used for: After the forklift has traveled a preset distance forward, the forklift is controlled to reverse a preset first distance according to the first reverse steering parameter; After the forklift has reversed a first distance, the forklift is controlled to reverse to the target baseline according to the second reverse steering parameter.

[0072] The rear axle center adjustment module 72 is also used for: During each forward or backward movement, determine the target distance between the current position of the rear axis center and the Y-axis; When the target distance reaches the preset error requirement, the rear axle center of the forklift is adjusted to the Y-axis.

[0073] The heading adjustment module 73 is also used for: The forklift is controlled to move forward or backward according to a preset steering angle, so as to adjust the forklift's heading to be parallel to the Y-axis of the preset coordinate system.

[0074] The forklift motion control device provided in this application, employing the forklift motion control method in the above embodiments, can solve the technical problems mentioned in the background art. Compared with the prior art, the beneficial effects of the forklift motion control device provided in this application are the same as those of the forklift motion control method provided in the above embodiments, and other technical features in the forklift motion control device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0075] This application provides a forklift motion control device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the forklift motion control method in Embodiment 1 above.

[0076] The following is for reference. Figure 8 , Figure 8This is a schematic diagram of the hardware operating environment involved in the forklift motion control method in this application embodiment. The forklift motion control device in this application embodiment may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), vehicle terminals (such as vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 8 The forklift motion control device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0077] like Figure 8 As shown, the forklift motion control device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory 1002 or a program loaded from a storage device 1003 into a random access memory 1004. The random access memory 1004 also stores various programs and data required for the operation of the forklift motion control device. The processing unit 1001, the read-only memory 1002, and the random access memory 1004 are interconnected via a bus 1005. An input / output interface 1006 is also connected to the bus. Typically, the following systems can be connected to the input / output interface 1006: input devices 1007 including, for example, a touch screen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage devices 1003 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. Communication device 1009 allows the forklift motion control equipment to communicate wirelessly or wiredly with other devices to exchange data. Although the figures show forklift motion control equipment with various systems, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0078] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from read-only memory 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0079] The forklift motion control device provided in this application, employing the forklift motion control method in the above embodiments, can solve the technical problems mentioned in the background art. Compared with the prior art, the beneficial effects of the forklift motion control device provided in this application are the same as those of the forklift motion control method provided in the above embodiments, and other technical features of the forklift motion control device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0080] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0082] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the forklift motion control method in the above embodiments.

[0083] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0084] The aforementioned computer-readable storage medium may be included in the forklift motion control device; or it may exist independently and not assembled into the forklift motion control device.

[0085] The aforementioned computer-readable storage medium carries one or more programs that, when executed by a forklift motion control device, cause the forklift motion control device to: determine the adjustable distance of the forklift and the current position of the rear axle center of the forklift; repeatedly adjust the position of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of a preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin; adjust the heading of the forklift to be parallel to the Y-axis of the preset coordinate system; and rotate the steering angle of the forklift to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the pallet's insertion holes. By repeatedly adjusting the position of the forklift within the adjustable distance until the center of the rear axle of the forklift is aligned with the Y-axis of the preset coordinate system, the heading of the forklift is adjusted to be parallel to the Y-axis so that the forklift is directly opposite the pallet. Furthermore, by setting the steering angle of the forklift to 0 degrees, the heading of the forklift can be kept basically unchanged, thereby ensuring that the forklift forks are accurately aligned and inserted into the holes of the pallet.

[0086] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0088] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0089] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described forklift motion control method, and is capable of solving the technical problems described in the background art. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the forklift motion control method provided in the above embodiments, and will not be repeated here.

[0090] This application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the forklift motion control method described above.

[0091] The computer program product provided in this application can solve the technical problems described in the background section. Compared with the prior art, the beneficial effects of the computer program product provided in the embodiments of this application are the same as the beneficial effects of the forklift motion control method provided in the above embodiments, and will not be repeated here.

[0092] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A forklift motion control method, characterized in that, include: Determine the adjustable distance of the forklift and the current position of the rear axle center of the forklift; Starting from the current position, the position of the rear axle center of the forklift is repeatedly adjusted within the adjustable distance until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system, wherein the preset coordinate system is a coordinate system constructed with the center point of the pallet as the origin. Adjust the forklift's heading to be parallel to the Y-axis of the preset coordinate system; The forklift's steering angle is rotated to 0 degrees to control the forklift to move forward until the forklift's forks are inserted into the pallet's slots.

2. The forklift motion control method as described in claim 1, characterized in that, The step of repeatedly adjusting the position of the rear axle center of the forklift within the adjustable distance, starting from the current position, until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system, includes: Starting from the current position, the forklift is controlled to move forward a preset distance according to the preset target forward steering parameters, wherein the preset distance does not exceed the adjustable distance; After the forklift has traveled a preset distance, it is controlled to retreat to the target baseline according to the preset target reverse steering parameters. The target baseline is a straight line that passes through the current position and is parallel to the X-axis of the preset coordinate system. Repeat the above forward and backward operations until the rear axle center of the forklift is aligned with the Y-axis of the preset coordinate system.

3. The forklift motion control method as described in claim 2, characterized in that, The target forward steering parameters include a first forward steering parameter and a second forward steering parameter; The first forward steering parameter and the second forward steering parameter correspond to different steering directions; The step of controlling the forklift to move a preset distance based on the current position and preset target forward steering parameters includes: Starting from the current position, the forklift is controlled to move forward a first distance according to the first forward steering parameters; After the forklift has traveled a first distance, it is controlled to travel a second distance according to the second forward steering parameter, wherein the sum of the first distance and the second distance is equal to the preset distance.

4. The forklift motion control method as described in claim 3, characterized in that, The first distance includes the target forward distance and the turning buffer distance; After the forklift has traveled a first distance, controlling the forklift to travel a second distance according to the second forward steering parameter includes: After the forklift has advanced the target forward sub-distance according to the first forward steering parameter, the forklift is controlled to start a steering switch, wherein when the forklift has turned and moved the steering buffer distance, the actual steering parameter of the forklift reaches the second forward steering parameter; The forklift is controlled to move forward a second distance according to the second forward steering parameter.

5. The forklift motion control method as described in claim 3 or 4, characterized in that, The step of controlling the forklift to travel a second distance according to the second forward steering parameter includes: Determine the forklift's deviation angle and wheelbase, wherein the deviation angle refers to the magnitude of the deviation from the forklift's initial angle, and the forklift's initial angle refers to the forklift's heading angle when the adjustment begins; The correction angle is calculated based on the deviation angle, the vehicle wheelbase, and the second distance; The second forward steering parameter is corrected according to the correction angle, so that the forklift can be controlled to move forward a second distance according to the corrected second forward steering parameter.

6. The forklift motion control method as described in claim 2, characterized in that, The target reverse steering parameters include a first reverse steering parameter and a second reverse steering parameter; the first reverse steering parameter and the second reverse steering parameter correspond to different steering directions; The step of controlling the forklift to reverse to the target baseline according to preset target reversing steering parameters after the forklift has traveled a preset forward distance includes: After the forklift has traveled a preset distance forward, the forklift is controlled to reverse a preset first distance according to the first reverse steering parameter; After the forklift has reversed a first distance, the forklift is controlled to reverse to the target baseline according to the second reverse steering parameter.

7. The forklift motion control method as described in claim 2, characterized in that, The repeated execution of the above forward and backward operations until the rear axle center of the forklift is adjusted to the Y-axis of the preset coordinate system includes: During each forward or backward movement, determine the target distance between the current position of the rear axis center and the Y-axis; When the target distance reaches the preset error requirement, the rear axle center of the forklift is adjusted to the Y-axis.

8. The forklift motion control method as described in claim 1, characterized in that, Adjusting the forklift's heading to be parallel to the Y-axis of the preset coordinate system includes: The forklift is controlled to move forward or backward according to a preset steering angle, so as to adjust the forklift's heading to be parallel to the Y-axis of the preset coordinate system.

9. A forklift motion control device, characterized in that, The forklift motion control device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the forklift motion control method as described in any one of claims 1 to 8.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the forklift motion control method as described in any one of claims 1 to 8.

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