A wing docking path planning method

Abstract

The application discloses a kind of unmanned aerial vehicle wing butt joint path planning method, it is related to unmanned aerial vehicle, mechanics, path planning technical field, the application is used to determine the path of unmanned aerial vehicle in air completes wing butt joint process.The method is first to discretize the region where the butt joint process is located, determine a plurality of path points distributed in the entire butt joint region, then calculate the aerodynamic interference at each path point, generate aerodynamic database, subsequently design cost function, find the optimized butt joint path by Dijkstra algorithm.The application can realize the path planning in the wing butt joint process of unmanned aerial vehicle, reduce the aerodynamic interference received in the butt joint process of unmanned aerial vehicle, enhance the stability of butt joint process.

Description

Technical Field

[0001] This invention relates to the fields of unmanned aerial vehicles (UAVs), mechanics, and path planning, specifically a method for determining the path of an UAV during the wing docking process in the air. Background Technology

[0002] With the widespread application of unmanned aerial vehicle (UAV) technology, multi-body combined UAVs, composed of multiple UAVs docked together by wing-to-wing docking, have gradually become a research hotspot in order to leverage the advantages of small, individual UAVs in terms of flexibility and maneuverability, while simultaneously improving the flight efficiency and loiter time of small UAV swarms. However, due to the existence of aerodynamic coupling effects, the UAV wing-to-wing docking process suffers from significant aerodynamic interference, affecting the safety and stability of the docking process. Existing path planning methods only design cost functions based on distance and speed, failing to consider the aerodynamic interference problems caused by aerodynamic coupling effects.

[0003] Therefore, it is necessary to design a path planning method to find the path with the least aerodynamic interference to the UAV during the docking process, thereby improving the safety and stability of the docking process. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to disclose a path planning method for determining the path of a UAV during wing docking, which addresses the path planning problem caused by aerodynamic interference during the wing docking process. The method first discretizes the area where the docking process occurs, identifying multiple path points distributed throughout the entire docking area. Then, it calculates the aerodynamic interference at each path point, generating an aerodynamic database. Subsequently, a cost function is designed, and the optimized docking path is found using Dijkstra's algorithm. This invention can realize path planning during the UAV wing docking process, reducing aerodynamic interference encountered during docking and enhancing the stability of the docking process.

[0005] Specifically, the following steps are included:

[0006] The two drones involved in the docking are divided into a lead drone and a follower drone. The start and end points of the docking process are determined, the docking area is divided, and multiple path points distributed throughout the docking area are identified and numbered.

[0007] Calculations were performed using aerodynamic simulation software to construct an aerodynamic database;

[0008] Design a cost function, obtain the path length between two path points from the aerodynamic database, and generate the corresponding adjacency matrix;

[0009] Using the adjacency matrix, the starting point, and the ending point as input, the Dijkstra algorithm is used to plan the optimal path and output the path points traversed.

[0010] Connecting the obtained optimal path points yields a smooth curve, which determines the docking path.

[0011] Furthermore, the method for determining the starting point, ending point, docking area, path points, and their numbers in the docking process is as follows:

[0012] The body coordinate system of the lead aircraft is used as the global coordinate system. The position of the follower aircraft when docking begins is taken as the starting point, and the position of the follower aircraft when the wing docking of the two aircraft is completed is taken as the ending point.

[0013] Establish a spatial plane or geometric shape by using the line connecting the starting point and the ending point as the diagonal, and determine the docking area;

[0014] The area is divided evenly, and path points are evenly distributed throughout the docking area and numbered sequentially.

[0015] Furthermore, the pneumatic database construction process is as follows:

[0016] The calculation conditions are determined based on the path point numbers and the relative positions of the two corresponding drones;

[0017] Aerodynamic modeling and calculation were performed to obtain the aerodynamic forces and aerodynamic moments experienced by the two UAVs under the corresponding working conditions at the path point.

[0018] Process the above calculation results and construct the database according to the path point numbers.

[0019] Furthermore, the cost function is calculated as follows:

[0020] For two coordinate points numbered i and j, the position coordinates of the path points are respectively (x, j) i ,y i ,z i ) and (x j ,y j ,z j If the relative distance is L, then the relative distance is L. i,j Defined as:

[0021]

[0022] The corresponding element G(i,j) in the adjacency matrix is ​​determined by the following cost function:

[0023]

[0024] In the formula, K F and K M F0 and M0 are dimensionless coefficients, representing the docking endpoint, i.e., the aerodynamic forces and torques corresponding to the completed docking state.i and M i Let F be the aerodynamic force and aerodynamic moment at coordinate point i. j and M j Let J represent the aerodynamic force and aerodynamic moment at coordinate point j. This adjacency matrix is ​​a dimensionless non-negative real matrix that takes into account both aerodynamic force and aerodynamic moment.

[0025] K F and K M F0 and M0 are dimensionless coefficients, representing the aerodynamic forces and torques corresponding to the endpoint, i.e., the docking completion state. This adjacency matrix is ​​a dimensionless non-negative real matrix that comprehensively considers the aerodynamic forces and torques.

[0026] Furthermore, the method for determining the path points is as follows:

[0027] The path point numbers traversed by the optimal path output by Dijkstra's algorithm;

[0028] Based on the correspondence of the path point numbers, the actual coordinates of the corresponding path points are obtained after conversion;

[0029] Based on the coordinates of the obtained discrete points, a smooth docking path is obtained by curve fitting.

[0030] The beneficial effects of this invention are as follows: by introducing aerodynamic forces and aerodynamic torques into the cost function, the important factor of aerodynamic interference is introduced into the path planning method. With this cost function, the method considers the significant impact of aerodynamic coupling effects during the docking process, and the determined docking path can reduce aerodynamic interference during docking, thereby improving the stability and safety of the docking process. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the wing docking path planning method of the present invention;

[0032] Figure 2 This is the optimal path in the embodiments of the present invention. Detailed Implementation

[0033] To more clearly illustrate the embodiments of the present invention or the existing technical solutions, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] To illustrate the technical features of the present invention, specific embodiments are described in further detail with reference to the accompanying drawings and examples. The following embodiments are used to illustrate the present invention but are not intended to limit its scope.

[0035] The embodiments of the present invention include:

[0036] like Figure 1 As shown, a wing docking path planning method includes:

[0037] Step S001: Divide the two drones involved in the docking into a lead drone and a follower drone, determine the start and end points of the docking process, divide the docking area, determine multiple path points distributed throughout the docking area, and number them.

[0038] Furthermore, the method for determining the starting point, ending point, docking area, path points, and their numbers in the docking process is as follows:

[0039] The body coordinate system of the lead aircraft is used as the global coordinate system. The position of the follower aircraft when docking begins is taken as the starting point, and the position of the follower aircraft when the wing docking of the two aircraft is completed is taken as the ending point.

[0040] Establish a spatial plane or geometric shape by using the line connecting the starting point and the ending point as the diagonal, and determine the docking area;

[0041] The area is divided evenly, and path points are evenly distributed throughout the docking area and numbered sequentially.

[0042] Step S002: Calculate using an aerodynamic simulation program to construct an aerodynamic database;

[0043] Furthermore, the pneumatic database construction process is as follows:

[0044] The calculation conditions are determined based on the path point numbers and the relative positions of the two corresponding drones;

[0045] Aerodynamic modeling and calculation were performed to obtain the aerodynamic forces and aerodynamic moments experienced by the two UAVs under the corresponding working conditions at the path point.

[0046] Process the above calculation results and construct the database according to the path point numbers.

[0047] Step S003: Design the cost function, obtain the path length between two path points from the aerodynamic database, and generate the corresponding adjacency matrix;

[0048] Furthermore, the cost function is calculated as follows:

[0049] For two coordinate points numbered i and j, the position coordinates of the path points are respectively (x, j)i ,y i ,z i ) and (x j ,y j ,z j If the relative distance is L, then the relative distance is L. i,j Defined as:

[0050]

[0051] The corresponding element G(i,j) in the adjacency matrix is ​​determined by the following cost function:

[0052]

[0053] In the formula, K F and K M F0 and M0 are dimensionless coefficients, representing the docking endpoint, i.e., the aerodynamic forces and torques corresponding to the completed docking state. i and M i Let F be the aerodynamic force and aerodynamic moment at coordinate point i. j and M j Let J represent the aerodynamic force and aerodynamic moment at coordinate point j. This adjacency matrix is ​​a dimensionless non-negative real matrix that takes into account both aerodynamic force and aerodynamic moment.

[0054] Step S004: Using the adjacency matrix, the starting point, and the ending point as input, perform optimal path planning using Dijkstra's algorithm and output the path points traversed.

[0055] Step S005: Connect the obtained optimal path points to obtain a smooth curve and determine the docking path.

[0056] Furthermore, the method for determining the path points is as follows:

[0057] The path point numbers traversed by the optimal path output by Dijkstra's algorithm;

[0058] The actual coordinates of the corresponding path points are obtained after conversion;

[0059] Based on the coordinates of the obtained discrete points, a smooth docking path is obtained by curve fitting.

[0060] Figure 2 This is an optimal path obtained according to the method. When the two UAVs begin their docking maneuver, there is a relative distance of 4m in both the horizontal and vertical directions. According to the method, a calculation case is determined every 0.2m. After aerodynamic simulation calculation, the adjacency matrix is ​​generated according to the cost function. Then, the path points of the optimal path are given according to Dijkstra's algorithm. Finally, the optimal path in the docking process is obtained.

[0061] Matters not covered in this invention are common knowledge. The above embodiments are only for illustrating the technical concept and features of this invention, and are intended to enable those skilled in the art to understand the content of this invention and implement it accordingly. They should not be construed as limiting the scope of protection of this invention. All equivalent changes or modifications made in accordance with the spirit and essence of this invention should be covered within the scope of protection of this invention.

Claims

1. A wing docking path planning method, characterized in that, The method is as follows: The two drones involved in the docking are divided into a lead drone and a follower drone. The start and end points of the docking process are determined, the docking area is divided, and multiple path points distributed throughout the docking area are identified and numbered. Calculations were performed using aerodynamic simulation software to construct an aerodynamic database; Design a cost function, obtain the path length between two path points from the aerodynamic database, and generate the corresponding adjacency matrix; Using the adjacency matrix, the starting point, and the ending point as input, the Dijkstra algorithm is used to plan the optimal path and output the path points traversed. Connecting the obtained optimal path points yields a smooth curve, which determines the docking path; The cost function is calculated as follows: For the number is and The coordinates of the two coordinate points and the position coordinates of the path points are respectively and The relative distance is Defined as: ； Corresponding elements in the adjacency matrix It is determined by the following cost function: ； In the formula, and The coefficient is dimensionless. and The endpoint of the docking process, i.e., the aerodynamic forces and torques corresponding to the completed docking state, and For the number Aerodynamic forces and aerodynamic moments at the coordinate points, and For the number The aerodynamic forces and aerodynamic moments at the coordinate points are given by the adjacency matrix, which is a dimensionless non-negative real matrix that takes into account both aerodynamic forces and aerodynamic moments. By introducing aerodynamic forces and aerodynamic torques into the cost function and aerodynamic disturbances into the path planning method, the significant impact of aerodynamic coupling effects on the docking process is considered through this cost function. The determined docking path can reduce aerodynamic disturbances during the docking process, thereby improving the stability and safety of the docking process.

2. The wing docking path planning method according to claim 1, characterized in that, The method for determining the starting point, ending point, docking area, path points, and their numbers in the docking process is as follows: The body coordinate system of the lead aircraft is used as the global coordinate system. The position of the follower aircraft when docking begins is taken as the starting point, and the position of the follower aircraft when the wing docking of the two aircraft is completed is taken as the ending point. Establish a spatial plane or geometric shape by using the line connecting the starting point and the ending point as the diagonal, and determine the docking area; The area is divided evenly, and path points are evenly distributed throughout the docking area and numbered sequentially.

3. The wing docking path planning method according to claim 1, characterized in that, The process of constructing the aerodynamic database is as follows: The calculation conditions are determined based on the path point numbers and the relative positions of the two corresponding drones; Aerodynamic modeling and calculation were performed to obtain the aerodynamic forces and aerodynamic moments experienced by the two UAVs under the corresponding working conditions at the path point. Process the above calculation results and construct the database according to the path point numbers.

4. The wing docking path planning method according to claim 1, characterized in that, The path point determination method for the cost function is as follows: The path point numbers traversed by the optimal path output by Dijkstra's algorithm; Based on the correspondence of the path point numbers, the actual coordinates of the corresponding path points are obtained after conversion; Based on the coordinates of the obtained discrete points, a smooth docking path is obtained by curve fitting.

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