Single-rudder wheel AGV automatic insertion track method and device, and storage medium

Abstract

The application discloses a single-rudder wheel AGV automatic insertion track method and equipment, and a storage medium, and the method comprises the following steps: according to a plurality of control point coordinates, an envelope line diagram of a path track is reproduced, a scanning discrete point meeting a set scanning condition is screened out by using a constructed scanning semicircle, a corresponding scanning track point is obtained, an optimal insertion path planning problem is converted into an optimal solution of a nonlinear programming problem, an optimal scanning track point is selected as an optimal insertion track point by solving the nonlinear programming problem, an optimal distance control quantity constituting an insertion path is obtained, and the optimal insertion track point and the optimal distance control quantity are input into a constructed insertion path model to obtain an optimal insertion path. Based on the characteristics of a cubic B-spline curve and the method for solving the nonlinear optimal solution, the single-rudder wheel AGV automatic insertion track is optimized, so that the AGV can automatically generate an insertion path track, intelligently insert the track, and accurately arrive at the optimal insertion track point.

Description

Technical Field

[0001] This invention relates to the field of AGV control technology, and in particular to a method, device, and storage medium for automatic trajectory insertion of a single-steering wheel AGV. Background Technology

[0002] In industrial AGVs, AGVs have become a widely used type of unmanned material handling equipment. Most AGVs currently on the market have a single steering wheel structure and move along a pre-set path. An AGV will only operate normally when it confirms that it is on the preset path; otherwise, the vehicle needs to be inserted into the path before it can continue to be used.

[0003] When an AGV deviates from its set trajectory due to manual operation or other reasons, it used to be manually operated by observing the AGV's current coordinates and path point coordinates to manually insert it. However, this insertion method is difficult to control, takes a long time, and has a large error, which does not meet the current standards of intelligent operation. Summary of the Invention

[0004] The purpose of this invention is to provide a method, device, and storage medium for automatic trajectory insertion of a single-steering wheel AGV, in order to solve one or more technical problems existing in the prior art, or at least provide a beneficial option or create conditions.

[0005] The solution to the technical problem of this invention is to provide a method, device, and storage medium for automatic trajectory insertion of a single-steering wheel AGV.

[0006] According to an embodiment of a first aspect of the present invention, a method for automatic trajectory insertion of a single-steering wheel AGV is provided, comprising the following steps:

[0007] Based on the coordinates of several control points, the path trajectory is fitted using a cubic B-spline curve, and the envelope diagram of the path trajectory is reproduced. The envelope diagram consists of several envelope segments, each of which consists of several discrete points. All discrete points are labeled.

[0008] Using the current AGV's reference point as the origin, construct a scanning semicircle, and use the scanning semicircle to scan all discrete points to obtain several scanning discrete points that satisfy the set scanning conditions.

[0009] The discrete scanning points are mapped onto the path trajectory to obtain several scanning trajectory points, and the labels corresponding to the discrete scanning points are used as the labels corresponding to the scanning trajectory points.

[0010] Using the reference point as the starting point and the set insertion trajectory point as the ending point, input the distance control value, and use cubic B-spline curve fitting to construct the insertion path model;

[0011] The problem of finding the optimal insertion path is transformed into a nonlinear programming problem of finding the optimal solution.

[0012] Solve the nonlinear programming problem by traversing the scanning trajectory points to obtain the optimal distance control quantity and the optimal insertion trajectory point, and obtain the optimal insertion path according to the insertion path model.

[0013] Furthermore, the process of labeling all discrete points specifically includes:

[0014] The coordinates of several planned control points are numbered and sorted sequentially along the AGV's travel direction;

[0015] An envelope is determined by the coordinates of two adjacent control points. The equation of the envelope is:

[0016]

[0017] Where n+1 is the number of control points;

[0018] The sorted control points traverse all envelopes with the set step size to obtain all discrete points, and then label all the discrete points.

[0019] Furthermore, the process of obtaining the discrete scanning points specifically includes:

[0020] Obtain the reference point, wheelbase length, and heading direction of the current AGV. Using the reference point as the origin, rotate the heading direction ±90° to obtain the central angle, and construct the scanning semicircle with a radius of 4 times the wheelbase length.

[0021] Calculate the distance between the reference point and all discrete points and the angle between the straight line formed by the reference point and all discrete points and the direction of the vehicle's front. The scanning conditions are that the distance is less than 4 times the wheelbase length and the angle is less than ±90°.

[0022] Based on the set scanning conditions, all discrete points are scanned and filtered to obtain several discrete points that satisfy the set scanning conditions.

[0023] Furthermore, the process of obtaining the scanning trajectory points includes:

[0024] The coordinates of the corresponding control points are determined based on the labels of the scanned discrete points;

[0025] The scanning trajectory points are obtained based on the labels of the discrete scanning points and the corresponding control point coordinates.

[0026] Furthermore, the construction process of the insertion path model includes:

[0027] With the reference point (x) r ,y r ,θr Starting from , the inserted trajectory point (x) is set. cs ,y cs ,θ cs Using the endpoint as the input, input distance control values ​​M and N, and obtain the coordinates of six control points in sequence:

[0028] (x r -M*cosθ r ,y r -M*sinθ r ), (x r ,y r ), (z r +M*cosθ r ,y r +M*sinθ r ), (x cs -N*cosθ cs ,y cs -N*sinθ cs ), (x cs ,y cs ), (x cs +N*cosθ cs ,y cs +N*sinθ cs );

[0029] Based on the coordinates of the six control points, an insertion path model is obtained by fitting a cubic B-spline curve, wherein the insertion path consists of several discrete points.

[0030] Furthermore, the transformation of the optimal insertion path planning problem into a nonlinear programming problem of finding the optimal solution specifically includes:

[0031] The optimal insertion path planning problem is transformed into a nonlinear programming problem where the inputs are distance control variables M and N, the constraint function is the inequality constraint of the angular velocity of the steering wheel angle, and the objective function is to find the minimum total cost with the sum of the turning radii of the discrete points on the path as the total cost.

[0032] input M,N

[0033] min Cost

[0034] subjuct to C≤MaxValue

[0035] Where MaxValue is the calibrated angular velocity.

[0036] Furthermore, the solution method for the nonlinear programming problem specifically includes:

[0037] Calculate the turning radius R at the discrete points of the path, use the curvature as an indicator of the cost value, and calculate the total cost value. Where n is the number of discrete points along the path;

[0038] Obtain the position coordinates (x, y) of the steering wheel relative to the reference point. f ,y f According to the position coordinates (x) f ,y f Given the curvature k, the steering wheel angle α of the AGV traveling on the inserted trajectory is obtained:

[0039]

[0040] Based on the steering wheel rotation angle α, the angular velocity of the steering wheel rotation angle is obtained.

[0041]

[0042] Among them, v s Set the AGV's travel speed, traverse the insertion path, and obtain the angular velocity. The maximum value, then

[0043] Furthermore, the process of obtaining the optimal insertion path specifically includes:

[0044] According to the solution method of the nonlinear programming problem, the scanning trajectory points are traversed and the total cost value cost is compared one by one.

[0045] The minimum value among the total cost values ​​is selected. Based on the minimum value of the total cost value, the optimal distance control quantities M and N and the optimal insertion trajectory points are obtained and input into the insertion path model to obtain the optimal insertion path.

[0046] According to a second aspect of the present invention, an electronic device is provided, comprising:

[0047] A memory for storing a program; a processor for executing the program stored in the memory, wherein when the processor executes the program stored in the memory, the processor is configured to execute a single-steering wheel AGV automatic trajectory insertion method as described in any one of the first aspects.

[0048] According to a third aspect of the present invention, a storage medium is provided, comprising: storing computer-executable instructions for performing a single-steering wheel AGV automatic trajectory insertion method as described in any one of the first aspects.

[0049] The beneficial effects of this invention are as follows: Based on the coordinates of several control points, the envelope diagram of the path trajectory is reproduced. Using the constructed scanning semicircle, discrete scanning points that meet the set scanning conditions are selected, thereby obtaining the corresponding scanning trajectory points. The optimal insertion path planning problem is transformed into finding the optimal solution to a nonlinear programming problem. By solving the nonlinear programming problem, the optimal scanning trajectory points are selected as the optimal insertion trajectory points, and the optimal distance control quantity constituting the insertion path is obtained. The optimal insertion trajectory points and the optimal distance control quantity are input into the constructed insertion path model to obtain the optimal insertion path. Based on the characteristics of cubic B-spline curves and the method of finding nonlinear optimal solutions, the automatic insertion trajectory of a single-steering wheel AGV is optimized, enabling the AGV to automatically generate insertion path trajectories, intelligently insert trajectories, and accurately reach the optimal insertion trajectory points. Attached Figure Description

[0050] Figure 1 This is a schematic flowchart of a single-steering wheel AGV automatic trajectory insertion method provided by the present invention;

[0051] Figure 2 This is a schematic diagram of the trajectory and envelope relationship of an automatic trajectory insertion method for a single-steering wheel AGV provided by the present invention;

[0052] Figure 3 This is a schematic diagram of the scanning semicircle construction of an automatic trajectory insertion method for a single-steering wheel AGV provided by the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and should not be construed as limiting the scope of the invention.

[0054] It should be noted that although functional modules are divided in the system diagram, in some cases, the steps shown or described may be executed in a different order than the module division or flowchart shown in the system. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0055] In the description of this invention, it should be noted that, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0056] Third-order B-spline curve: Based on the application scenario, several control point coordinates are defined within the AGV world coordinate system. The path trajectory is defined as P0, P1, P2, ..., P... dA total of d+1 control points are generated, where d ≥ 3. The path trajectory is obtained based on cubic B-spline curve fitting, and the d+1 control points are used to define the direction and length of the path trajectory. The definition of the cubic B-spline curve and its first derivative is:

[0057]

[0058]

[0059] Where t cycles according to a certain step size, and in this invention, the step size is set to 0.01. The equation of the cubic B-spline curve can be written as:

[0060] P(t) = P0 * B 0,3 (t)+P1*B 1,3 (t)+P2*B 2,3 (t)+P3*B 3,3 (t)

[0061] By iterating through (1.1), several discrete points (x) along the path trajectory can be obtained. c ,y c Correspondingly, according to (1.2) iterative iteration, and according to The corresponding attitude angle θ can be calculated. c Consists of several path discrete points (x c ,y c ,θ c The AGV path trajectory is composed of 4 control points, which determine a section of the path trajectory.

[0062] According to an embodiment of the first aspect of the present invention, referring to Figure 1 In some embodiments of the present invention, a method for automatic trajectory insertion of a single-steering wheel AGV includes the following steps:

[0063] S100: Based on the coordinates of several control points, fit the path trajectory using cubic B-spline curves and reproduce the envelope diagram of the path trajectory. The envelope diagram consists of several envelope segments, each of which consists of several discrete points. All discrete points are labeled.

[0064] In this embodiment, based on the usage scenario, several control point coordinates are determined. The AGV's forward path trajectory is obtained through cubic B-spline curve fitting. The control points are then sequentially numbered along the AGV's direction of travel to achieve sorting. Based on all the control point coordinates, the envelope diagram of the path trajectory is reproduced.

[0065] To improve the efficiency of the solution, if the coordinates of several control points are iterated using (1.1) and (1.2) in the third-order B-spline curve to reproduce the path trajectory points, it is equivalent to solving the cubic equation multiple times, which is time-consuming. Therefore, an envelope diagram that reproduces the path trajectory based on the coordinates of several control points is proposed.

[0066] An envelope diagram is composed of several envelope segments, all of which are straight lines. Each envelope segment is defined by pairwise control points, and each segment consists of several discrete points. By traversing the sorted control points according to a set step size, all discrete points of the envelope can be obtained. Specifically, each envelope segment consists of 100 discrete points. The discrete points of each envelope segment are labeled so that all discrete points are labeled in the format: point d of segment K.

[0067] S200: Using the reference point of the current AGV as the origin, construct a scanning semicircle, and use the scanning semicircle to scan all discrete points to obtain several scanning discrete points that meet the set scanning conditions.

[0068] In this embodiment, the current reference point of the AGV is obtained and used as the origin to construct a scanning semicircle. Discrete points falling within the scanning semicircle are those that satisfy the set scanning conditions. All discrete points are scanned using the scanning semicircle to obtain several discrete points falling within the scanning semicircle area. These several discrete points are considered as the scanned discrete points. These scanned discrete points are saved to the backend in the form of a structure, with pseudocode as follows:

[0069] (Envelope_Line(k).PartPoint(n).x e ,Envelope_Line(k).PartPoint(n).y e ).

[0070] S300: Map the discrete scanning points to the path trajectory to obtain several scanning trajectory points, and use the labels corresponding to the discrete scanning points as the labels corresponding to the scanning trajectory points.

[0071] In this embodiment, since the envelope graph is composed of several envelope segments, and the path trajectory is also composed of several path trajectory segments, the step size of the envelope is consistent with the step size of the path trajectory. Therefore, according to the characteristics of B-splines, the position of the discrete point of the envelope can map the position of the path trajectory segment where the trajectory point is located.

[0072] Mapping each discrete scanning point within the semicircle in S200 to the path trajectory yields several scanning trajectory points. These trajectory points also satisfy the set scanning conditions. The labels of the discrete scanning points are then assigned to the trajectory points as their labels. Since there are several discrete scanning points, there are also several scanning trajectory points. That is, the number of discrete scanning points is the same as the number of trajectory points.

[0073] S400 uses the reference point as the starting point and the set insertion trajectory point as the ending point. It inputs the distance control value and uses cubic B-spline curve fitting to construct the insertion path model.

[0074] In this embodiment, the insertion path can be understood as drawing a path with the AGV's reference point as the starting point and the trajectory point to be inserted as the ending point. Due to the characteristics of cubic B-splines, at least four control point coordinates are required to obtain the path segment. Therefore, a distance control value is set and input. Based on the AGV's reference point, the set insertion trajectory point, and the distance control value, the insertion path model is constructed by fitting a cubic B-spline curve.

[0075] In the insertion path model, the distance control variable represents the distance between control points and serves as the optimization variable.

[0076] S500 transforms the optimal insertion path planning problem into a nonlinear programming problem that seeks the optimal solution.

[0077] In this embodiment, to ensure insertion accuracy, the path needs to meet the following conditions: the angular velocity of the single steering wheel should not be too large, and the turning radius of the path should not be too small. Based on these conditions, a nonlinear programming problem is set up, transforming the search for the optimal insertion path into finding the optimal solution to the nonlinear programming problem. When this nonlinear programming problem has an optimal solution, the insertion path at this point is optimal.

[0078] S600 solves a nonlinear programming problem by traversing the scan trajectory points to obtain the optimal distance control quantity and the optimal insertion trajectory point, and obtains the optimal insertion path based on the insertion path model.

[0079] In this embodiment, the nonlinear programming problem set in S500 is solved by substituting the scan trajectory points obtained in S300 one by one into the nonlinear programming problem to achieve traversal of all scan trajectory points. By traversing all scan trajectory points, the optimal distance control value is output, and the optimal scan trajectory point is selected as the insertion trajectory point for the optimal path. The output optimal distance control value and the selected optimal scan trajectory are input into the insertion path model to obtain the optimal insertion path.

[0080] Based on the coordinates of several control points, the envelope diagram of the path trajectory is reproduced. Using the constructed scanning semicircle, discrete scanning points that meet the set scanning conditions are selected, thus obtaining the corresponding scanning trajectory points. The optimal insertion path planning problem is transformed into finding the optimal solution to a nonlinear programming problem. By solving the nonlinear programming problem, the optimal scanning trajectory points are selected as the optimal insertion trajectory points, and the optimal distance control quantity constituting the insertion path is obtained. The optimal insertion trajectory points and the optimal distance control quantity are input into the constructed insertion path model to obtain the optimal insertion path. Based on the characteristics of cubic B-spline curves and the method of finding nonlinear optimal solutions, the automatic insertion trajectory of a single-steering wheel AGV is optimized, enabling the AGV to automatically generate insertion path trajectories, intelligently insert trajectories, and accurately reach the optimal insertion trajectory points.

[0081] Reference Figure 2 In some embodiments of the present invention, the specific process of labeling all discrete points includes the following steps:

[0082] S110: Number several control points sequentially along the AGV's travel direction to achieve sorting.

[0083] In this embodiment, based on the usage scenario, the coordinates of several control points are determined, and the path trajectory of the AGV is obtained based on cubic B-spline curve fitting. The control points are then numbered sequentially along the AGV's direction of travel to achieve sorting.

[0084] S120, an envelope can be determined by pairwise control points, and the equation of the envelope is:

[0085]

[0086] In this embodiment, a segment of the envelope is determined by pairwise control points, and several segments of the envelope are all straight lines. Based on the coordinates of adjacent control points, a linear equation is established to obtain the equation of the envelope:

[0087]

[0088] Where n+1 represents the number of planned control points.

[0089] S130: According to the set step size, traverse the sorted control points to obtain all discrete points in the envelope diagram, and label all discrete points.

[0090] In this embodiment, the sorted control points are traversed according to a set step size, where the set step size is... After traversing all control points, the discrete points of all envelopes can be obtained. Each envelope segment consists of 100 discrete points. Each discrete point of the envelope segment is labeled with a number from 1 to 100, so that all discrete points are labeled. Thus, each discrete point of the envelope segment has a unique label, with the label format being: point d of segment K.

[0091] To improve efficiency, iterating through steps (1.1) and (1.2) of a third-order B-spline curve using the coordinates of several control points to reconstruct the path trajectory points (i.e., calculating the discrete points of the path) is equivalent to repeatedly solving a cubic equation, which is time-consuming. Therefore, we propose reconstructing the path trajectory using an envelope diagram based on the coordinates of several control points, and labeling all discrete points in the envelope diagram.

[0092] Reference Figure 3 In some embodiments of the present invention, the process of obtaining discrete scanning points specifically includes the following steps:

[0093] S210: Based on the current posture of the AGV, obtain the current reference point, wheelbase length, and current vehicle direction. Using the current reference point as the origin, a radius of 4 times the wheelbase length, and rotating the current vehicle direction ±90°, obtain a 180° central angle. Construct a scanning semicircle using the above conditions.

[0094] In this embodiment, based on the current posture of the AGV, the coordinates of the AGV's current reference point are obtained, and the current reference point coordinates are used as the origin. The AGV's heading direction is obtained, and a semicircle with a radius of 4 times the AGV's wheelbase is obtained by taking ±90 degrees of the AGV's heading direction as the reference point. This radius is determined through multiple tests, taking into account that the AGV has a certain insertion distance.

[0095] S220: Iterate through the distances between the reference point and the discrete point to obtain several distances, and calculate the angle between the line connecting the reference point and the discrete point and the direction of the AGV's head to obtain several angles. When the distance is less than 4 times the wheelbase length and the angle is less than ±90°, it is considered to meet the set scanning conditions.

[0096] In this embodiment, the distances between the reference point and all discrete points in the envelope graph are calculated, resulting in several distance values. Lines are drawn connecting the reference point and all discrete points in the envelope graph, resulting in several connecting lines. The angles between these connecting lines and the vehicle's orientation are calculated, resulting in several angle values. These distance and angle values ​​are then filtered. If a discrete point's distance is less than four times the wheelbase length and its angle is less than ±90°, then the discrete point is considered to fall within the scanning semicircle region, meeting the set scanning conditions.

[0097] S230: Using the set scanning conditions, scan and filter all discrete points to obtain a number of scanned discrete points, all of which meet the set scanning conditions.

[0098] In this embodiment, several distance values ​​and several included angle values ​​are selected. When the distance value of a discrete point is less than 4 times the axis distance length, and the included angle value of the discrete point is less than...

[0099] When the angle is ±90°, the discrete point is considered to fall within the scanning semicircle region, meeting the set scanning conditions. Using the set scanning conditions, all discrete points in the envelope diagram are filtered, and several discrete points that meet the set scanning conditions are considered the scanned discrete points. These points and their information are saved to the backend in the form of a structure, with pseudocode as follows:

[0100] (Envelope_Line(k).PartPoint(n).x e ,Envelope_Line(k).PartPoint(n).y e ).

[0101] Reference Figure 3 In some embodiments of the present invention, the process of obtaining the scanning trajectory points specifically includes the following steps:

[0102] S310, Based on the label of the scanned discrete point, determine the envelope of the scanned discrete point and the coordinates of the corresponding control point.

[0103] In this embodiment, since the envelope diagram is composed of several envelope segments, each envelope segment is determined by the coordinates of pairwise control points, and the path trajectory is also composed of several path trajectory segments, as shown in S130, the set step size of the envelope is consistent with the step size of the path trajectory. Therefore, according to the characteristics of B-splines, the position of the discrete points of the envelope can map the position of the path trajectory segments containing the trajectory points. For example, (x e ,y e () is the d-th point of the K-th segment. We know the d-th point of the envelope of the k-th segment of the scan discrete point, and determine the coordinates of the envelope of the k-th segment and the corresponding control point.

[0104] S320: Based on the coordinates and labels of the corresponding control points determined in S310, the scanning trajectory points are calculated.

[0105] In this embodiment, the position of the discrete point of the envelope segment can be mapped to the position of the trajectory point segment.

[0106] For example, discrete point (x) e ,y e If x is the d-th point of the k-th segment, then the trajectory point (x) c ,yc Mapping the d-th point of the k-th trajectory segment, the labels of the discrete points within the scanned semicircle are converted into trajectory point labels. Based on the d-th point of the k-th segment, i.e. By adding the corresponding control point coordinates and substituting them into the third-order B-spline curve, the coordinates of the trajectory points within the scanning semicircular area can be obtained, thus obtaining the scanning trajectory points.

[0107] By traversing a number of discrete scanning points, a number of scanning trajectory points are obtained. The number of discrete scanning points is the same as the number of scanning trajectory points.

[0108] In some embodiments of the present invention, the process of constructing the insertion path model specifically includes the following steps:

[0109] S410, set the trajectory point to be inserted as (x cs ,y cs ,θ cs ), and set it as the endpoint of the insertion path, with the AGV's reference point (x r ,y r ,θ r Starting from (x), input distance control values ​​M and N to obtain the coordinates of six control points: r -M*cosθ r ,y r -M*sinθ r ), (x r ,y r ), (z r +M*cosθ r ,y r +M*sinθ r ), (x cs -N*cosθ cs ,y cs -N*sinθ cs ), (x cs ,y cs ), (x cs +N*cosθ cs ,y cs +N*sinθ cs ).

[0110] In this embodiment, the insertion path can be understood as drawing a path with the AGV's reference point as the starting point and the trajectory point to be inserted as the ending point. Due to the characteristics of cubic B-splines, at least four control point coordinates are required to obtain a path segment. Therefore, distance control variables are set and input. In this embodiment, two distance control variables, M and N, are set. This allows the acquisition of six control point coordinates, which are then used to construct the insertion path. Here, the distance control variables M and N represent the distance between the control points and serve as optimization variables.

[0111] In this invention, two distance control variables, M and N, are used to set the coordinates of six control points. One or three distance control variables can also be used to set the control point coordinates; the number of distance control variables is not limited in this embodiment.

[0112] S420: Based on the coordinates of the six control points determined in S410, a cubic B-spline curve is fitted to obtain the insertion path model.

[0113] In this embodiment, based on the characteristics of cubic B-splines, the path trajectory is composed of several discrete path points, and a segment of the path trajectory is determined by four control points. Therefore, the inserted path is also composed of several discrete path points.

[0114] Based on the AGV's reference point, the set insertion trajectory point, and the distance control quantity, an insertion path model is constructed by fitting a cubic B-spline curve.

[0115] In some embodiments of the present invention, the nonlinear programming problem specifically includes:

[0116] S510, using distance control quantities M and N as input quantities, and taking the inequality constraint of the angular velocity of the AGV steering wheel rotation angle as the constraint function, the objective function is to find the minimum total cost with the sum of the turning radii of the discrete points on the path as the objective function, that is:

[0117] input M,N

[0118] min Cost

[0119] subjuct to C≤MaxValue

[0120] Where MaxValue is the calibrated angular velocity.

[0121] In this embodiment, to ensure insertion accuracy, the path needs to meet the following conditions: the angular velocity of the single steering wheel should not be too large, and the turning radius of the path should not be too small. Based on the above conditions, a nonlinear programming problem is set up, transforming the search for the optimal insertion path into finding the optimal solution to the nonlinear programming problem. When this nonlinear programming problem has an optimal solution, the insertion path is constructed using the distance control quantities M and N at this point. This insertion path is the optimal curve that meets the constraints and has the lowest cost.

[0122] In this invention, the calibrated angular velocity for a single-steering wheel AGV is set to 40*pi / 180.

[0123] In some embodiments of the present invention, the method for solving nonlinear programming problems specifically includes the following steps:

[0124] S610, calculate the turning radius R for several discrete points on the path, and obtain several turning radii R. The cost index is curvature k = R. -1 Calculate the total cost value

[0125] In this embodiment, the turning radius R is calculated as follows: for a current path discrete point (x c ,y c Add and subtract one step from the t value of ), and then substitute the values ​​of t-1 and t+1 into (1.1) to obtain the current path discrete point (x). s ,y s The coordinates (x) of the point before ) c-1 ,y c-1 ) and the coordinates (x) of the next point c+1 ,y c+1 Based on these three coordinates, the current path discrete point (x) is obtained. c ,y c The turning radius R at point ) c :

[0126]

[0127] By traversing several discrete points along the path using the above method for calculating the turning radius R, several turning radii are obtained. Since the goal is to minimize cost, the curvature k = R is used. -1 As an indicator of cost, several turning radii are converted into several curvatures, and the total cost is obtained by superimposing these curvatures. Where n is the number of discrete points in the inserted path.

[0128] S620, Obtain the installation position coordinates (x) of the steering wheel relative to the reference point. f ,y f If the AGV's steering wheel rotation angle α on the trajectory is:

[0129]

[0130] Angular velocity is calculated based on the steering wheel rotation angle.

[0131]

[0132] Angular velocity using discrete difference:

[0133]

[0134]

[0135] Traverse the entire insertion path and find the angular velocity. The maximum value, then

[0136] In this embodiment, the known mounting position coordinates (x, y) of the steering wheel relative to the reference point are... f ,y f According to the installation location coordinates (x f ,y f The curvature k is obtained from S610, and the steering wheel angle α is calculated.

[0137]

[0138] The angular velocity of the steering wheel is obtained by calculating using the steering wheel rotation angle α.

[0139]

[0140] Angular velocity using discrete difference:

[0141]

[0142]

[0143] The AGV is set to travel at a speed of v. s Traverse the entire insertion path and find the angular velocity. The maximum value, then

[0144] In some embodiments of the present invention, the process of obtaining the optimal insertion path specifically includes the following steps:

[0145] S630 uses a nonlinear programming problem-solving method to traverse the scanning trajectory points, solve each scanning trajectory point one by one, and compare the cost values ​​one by one.

[0146] In this embodiment, the coordinates of all scan trajectory points within the scanned semicircular region are solved one by one. If no solution is found, the point is discarded, and the scan trajectory points with solutions are saved. The cost value is then compared for each scan trajectory point with a solution.

[0147] S640 takes the set of data with the minimum cost value as the optimal solution, outputs the optimal distance control values ​​M and N and the optimal insertion trajectory points, substitutes them into the insertion path model, and calculates the optimal insertion path.

[0148] In this embodiment, the path with the lowest cost value is selected as the optimal insertion path, and the corresponding optimal distance control values ​​M and N, along with the scan trajectory point, are output. The scan trajectory point is then used as the optimal insertion trajectory point (x). cs ,y cs ,θ cs Based on the optimal insertion trajectory point (x) cs ,ycs ,θ cs The optimal distance control values ​​M and N are input into the insertion path model to obtain the coordinates of six control points. Based on the coordinates of the six control points, the optimal insertion path is obtained using cubic B-splines.

[0149] According to an embodiment of a second aspect of the present invention, an electronic device includes: a memory for storing a program; and a processor for executing the program stored in the memory, wherein when the processor executes the program stored in the memory, the processor is configured to execute a single-steering wheel AGV automatic trajectory insertion method according to the first aspect.

[0150] The processor and memory can be connected via a bus or other means.

[0151] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs, such as the AGV dual-radar installation error calibration method described in the embodiments of the present invention. The processor implements the path tracking control method for the forklift AGV according to the first aspect of the present invention by running the non-transitory software program and instructions stored in the memory.

[0152] The memory may include a program storage area and a parameter storage area. The program storage area may store the operating system and application programs required for at least one function. The parameter storage area may store the above-described method for calibrating the installation error of the AGV dual radar. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0153] The non-transient software program and instructions required to implement the above-described terminal selection method are stored in memory. When executed by one or more processors, they are used to implement the path tracking control method of the forklift AGV of the first aspect of the present invention.

[0154] According to an embodiment of the third aspect of the present invention, the present invention also provides a storage medium storing computer-executable instructions for executing a single-steering wheel AGV automatic trajectory insertion method according to the first aspect.

[0155] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, parameter structures, program modules, or other parameters). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, parameter structures, program modules, or other parameters in modulation parameter signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0156] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for automatic trajectory insertion of a single-steering-wheel AGV, characterized in that, include: Based on the coordinates of several control points, the path trajectory is fitted using a cubic B-spline curve, and the envelope diagram of the path trajectory is reproduced. The envelope diagram consists of several envelope segments, each of which consists of several discrete points. All discrete points are labeled. Using the current AGV's reference point as the origin, construct a scanning semicircle, and use the scanning semicircle to scan all discrete points to obtain several scanning discrete points that satisfy the set scanning conditions. The discrete scanning points are mapped onto the path trajectory to obtain several scanning trajectory points, and the labels corresponding to the discrete scanning points are used as the labels corresponding to the scanning trajectory points. Using the reference point as the starting point and the set insertion trajectory point as the ending point, input the distance control value, and use cubic B-spline curve fitting to construct the insertion path model; The problem of finding the optimal insertion path is transformed into a nonlinear programming problem of finding the optimal solution. Solve the nonlinear programming problem by traversing the scanning trajectory points to obtain the optimal distance control quantity and the optimal insertion trajectory point, and obtain the optimal insertion path based on the insertion path model; The process of obtaining the discrete scanning points specifically includes: Obtain the current AGV's reference point, wheelbase length, and heading direction. Using the reference point as the origin, determine the heading direction... The angle obtained by rotation is the central angle, and the radius is four times the axial length to construct the scanning semicircle; Calculate the distance between the reference point and all discrete points, and the angle between the straight line formed by the reference point and all discrete points and the direction of the vehicle's front. The scanning conditions are that the distance is less than 4 times the wheelbase length and the angle is less than... ; Based on the set scanning conditions, all discrete points are scanned and filtered to obtain several discrete points that satisfy the set scanning conditions. The transformation of the optimal insertion path planning problem into a nonlinear programming problem of finding the optimal solution specifically includes: The problem of finding the optimal insertion path is transformed into finding the distance control variable as the input. The constraint function is an inequality constraint on the angular velocity of the steering wheel, and the objective function is a nonlinear programming problem that seeks to minimize the total cost by summing the turning radii of the discrete points on the path, i.e.: in, The angular velocity is the calibrated value.

2. The method for automatic trajectory insertion of a single-steering wheel AGV according to claim 1, characterized in that, The process of labeling all discrete points specifically includes: The coordinates of several planned control points are numbered and sorted sequentially along the AGV's travel direction; An envelope is determined by the coordinates of two adjacent control points. The equation of the envelope is: Where n+1 is the number of control points; The sorted control points are traversed through all envelopes with the set step size to obtain all discrete points, and all discrete points are labeled.

3. The method for automatic trajectory insertion of a single-steering wheel AGV according to claim 2, characterized in that, The process of obtaining the scan trajectory points includes: The coordinates of the corresponding control points are determined based on the labels of the scanned discrete points; The scanning trajectory points are obtained based on the labels of the discrete scanning points and the corresponding control point coordinates.

4. The method for automatic trajectory insertion of a single-steering wheel AGV according to claim 1, characterized in that, The process of constructing the insertion path model includes: With the aforementioned reference point Starting from the designated point, the trajectory points are set. Input distance control quantity as the endpoint. The coordinates of the six control points were obtained sequentially: 、 、 、 ； Based on the coordinates of the six control points, an insertion path model is obtained by fitting a cubic B-spline curve, wherein the insertion path consists of several discrete points.

5. The method for automatic trajectory insertion of a single-steering wheel AGV according to claim 1, characterized in that, The specific methods for solving the nonlinear programming problem include: Calculate the turning radius of the discrete points on the path. Using curvature as an indicator of cost value, the total cost value is calculated. ,in, The number of discrete points along the path; Obtain the position coordinates of the steering wheel relative to the reference point. According to the position coordinates and curvature Obtain the steering wheel angle of the AGV traveling on the inserted trajectory. : According to the steering wheel angle The angular velocity of the steering wheel rotation angle is obtained. : in, Set the AGV's travel speed, traverse the insertion path, and obtain the angular velocity. The maximum value, then .

6. The method for automatic trajectory insertion of a single-steering wheel AGV according to claim 5, characterized in that, The process of obtaining the optimal insertion path specifically includes: According to the solution method for the nonlinear programming problem, the scanning trajectory points are traversed, and the total cost value is compared one by one. ; Select the total cost value The minimum value in, based on the total cost value The minimum value is used to obtain the optimal distance control quantity. The optimal insertion trajectory point is then input into the insertion path model to obtain the optimal insertion path.

7. An electronic device, characterized in that, include: Memory, used to store programs; A processor is configured to execute a program stored in the memory, wherein when the processor executes the program stored in the memory, the processor is configured to perform a single-steering wheel AGV automatic trajectory insertion method as described in any one of claims 1 to 6.

8. A storage medium, characterized in that, include: The device stores computer-executable instructions for performing a single-steering wheel AGV automatic trajectory insertion method as described in any one of claims 1 to 6.

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