Stratospheric airship path planning method and device, medium and product

Abstract

The invention discloses a stratospheric airship path planning method and device, a medium and a product, and relates to the technical field of airship path planning, and the method comprises the steps: obtaining a path planning parameter of a stratospheric airship; starting from the starting node of the current time period, performing path planning on the current time period by using an improved A * algorithm based on the path planning parameters to obtain a path node set of the current time period; judging whether the last node in the path node set in the current time period is a target node or not; if yes, determining the starting node, the target node and each intermediate node as an optimal path node set, smoothing the optimal path node set by using a B-spline interpolation method to obtain an optimal path, and controlling the stratospheric airship to reach the target node from the starting node according to the optimal path; and if not, continuing planning. According to the invention, dynamic path planning of the stratospheric airship is realized.

Description

Technical Field

[0001] The present application relates to the technical field of airship path planning, and in particular, to a stratospheric airship path planning method, device, medium and product. Background Art

[0002] As a new type of high-altitude aircraft, the stratospheric airship has the characteristics of long endurance and high-altitude flight, and can be widely used in fields such as meteorological monitoring, communication relay, and earth observation. However, due to the lack of a real-time airspeed sensor on the stratospheric airship and its low dynamic response characteristics, its control problem is relatively complex. In addition, the uneven distribution and prediction error of the stratospheric wind field pose higher requirements for the path planning of the airship.

[0003] Therefore, a stratospheric airship path planning method is needed. Summary of the Invention

[0004] The purpose of the present application is to provide a stratospheric airship path planning method, device, medium and product to solve the problem that the dynamic path planning of the stratospheric airship cannot be realized.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] In the first aspect, the present application provides a stratospheric airship path planning method, including:

[0007] Obtain the path planning parameters of the stratospheric airship; the path planning parameters include: predicted wind field data, airspeed, and the topological structure of the flight area; the topological structure includes multiple nodes, and the nodes are departure nodes, target nodes, obstacle nodes, or feasible nodes; the predicted wind field data includes: the wind speeds of each grid in the stratosphere at multiple moments updated according to a set time step starting from the departure moment, the wind speeds of each grid at the same moment are equal, and one grid corresponds to one node;

[0008] Determine the departure moment as the 0th wind field update moment, and determine the moment obtained by adding a set time steps to the departure moment as the ath wind field update moment;

[0009] Determine the time period from the (b - 1)th wind field update moment to the bth wind field update moment as the bth time period, and determine the wind speed at the (b - 1)th wind field update moment as the wind speed of the bth time period; b ≥ 1;

[0010] Determine any time period as the current time period, and determine the stop node of the previous time period as the start node of the current time period; the stop node of any time period is the last node in the path node set of the time period, and the path node set includes multiple path nodes; among them, when the current time period is the 1st time period, the stop node of the previous time period is the departure node;

[0011] Starting from the starting node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning for the current time period to obtain the path node set of the current time period; the cost function of the improved A* algorithm is a function of distance cost, energy cost, and time cost;

[0012] During the process of performing path planning for the current time period, real-time judge whether the last node in the path node set of the current time period is the target node;

[0013] If so, determine the starting node, the target node, and each intermediate node as the optimal path node set, and use the B-spline interpolation method to smooth the optimal path node set to obtain the optimal path, and control the stratospheric airship to reach the target node from the starting node according to the optimal path; the intermediate node is the path node between the starting node and the target node;

[0014] If not, use the improved A* algorithm to continue performing path planning for the current time period, update the path node set of the current time period until the current time period ends, update the stop node of the previous time period to the stop node of the current time period, update the current time period to the next time period, and return "Starting from the starting node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning for the current time period to obtain the path node set of the current time period".

[0015] Optionally, starting from the starting node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning for the current time period to obtain the path node set of the current time period, including:

[0016] For any current path node in the path node set of the current time period, determine the next path node of the current path node according to the principle of the minimum estimated cost of the cost function;

[0017] Judge whether the next path node is the target node;

[0018] If so, based on the next path node and all path nodes in the current time period before the next path node, obtain the path node set of the current time period;

[0019] If not, update the current path node to the next path node, and return "For any current path node in the path node set of the current time period, determine the next path node of the current path node according to the principle of the minimum estimated cost of the cost function".

[0020] Optionally, the process of determining the next path node after any current path node in the path node set of the current time period includes:

[0021] Determine any surrounding feasible node of the current path node as the next node to be screened; the surrounding feasible nodes of the current path node are the feasible nodes among the nodes corresponding to the eight grids other than the current grid in the nine-grid centered on the current grid, and the current grid is the grid corresponding to the current path node;

[0022] Determine the surrounding obstacle nodes of the current path node; the surrounding obstacle nodes of the current path node are the obstacle nodes among the nodes corresponding to the eight grids other than the current grid in the nine-grid centered on the current grid;

[0023] Obtain the estimated cost from the start node of the current time period to the next node to be screened, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the position coordinates of the current path node, and the potential energy function value of the current path node; when the current time period is the first time period, the estimated cost from the start node to the next node to be screened is 0; when the current time period is not the first time period, the estimated cost from the start node at the current moment to the next node to be screened is based on the airspeed, the wind speed in the current time period, the position coordinates of the start node in the current time period, the position coordinates of the next node to be screened, the position coordinates of the obstacle nodes among the nodes corresponding to the eight grids other than the grid corresponding to the penultimate path node in the previous time period in the nine-grid centered on the grid corresponding to the penultimate path node in the previous time period, the potential energy function value of the penultimate path node in the previous time period, and the position coordinates of the penultimate path node in the previous time period;

[0024] Based on the airspeed, the wind speed in the current time period, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the potential energy function value of the current path node, and the position coordinates of the current path node, determine the estimated cost from the next node to be screened to the target node;

[0025] Based on the estimated cost from the start node of the current time period to the next node to be screened and the estimated cost from the next node to be screened to the target node, determine the total estimated cost of the next node to be screened;

[0026] Determine the next path node as the next node to be screened with the minimum total estimated cost.

[0027] Optionally, based on the airspeed, the wind speed in the current time period, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the potential energy function value of the current path node, and the position coordinates of the current path node, determining the estimated cost from the next node to be screened to the target node includes:

[0028] Determine an estimated value of the distance cost from the next node to be screened to the target node based on the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, and the position coordinates of the current path node;

[0029] Determine an estimated value of the time cost from the next node to be screened to the target node based on the airspeed, the wind speed in the current period, the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period;

[0030] Determine an estimated value of the energy cost from the next node to be screened to the target node based on the position coordinates of the current path node, the position coordinates of the next node to be screened, the ground speed in the current period, and the wind speed in the current period;

[0031] Determine the estimated cost from the next node to be screened to the target node based on the estimated value of the distance cost, the estimated value of the time cost, and the estimated value of the energy cost of the next node to be screened.

[0032] Optionally, determining an estimated value of the distance cost from the next node to be screened to the target node based on the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, and the position coordinates of the current path node includes:

[0033] Determine the gravitational field of the next node to be screened based on the position coordinates of the next node to be screened and the position coordinates of the target node;

[0034] Determine the repulsive field of the next node to be screened based on the position coordinates of the next node to be screened and the position coordinates of the surrounding obstacle nodes;

[0035] Determine the potential energy function value of the next node to be screened based on the gravitational field of the next node to be screened and the repulsive field of the next node to be screened;

[0036] Determine an estimated value of the distance cost from the next node to be screened to the target node based on the potential energy function value of the next node to be screened, the potential energy function value of the current path node, the position coordinates of the next node to be screened, and the position coordinates of the current path node.

[0037] Optionally, determining an estimated value of the time cost from the next node to be screened to the target node based on the airspeed, the wind speed in the current period, the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period includes:

[0038] Determine the ground speed in the current period based on the airspeed and the wind speed in the current period;

[0039] Determine an estimated value of the time cost from the next node to be screened to the target node based on the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period.

[0040] Optionally, based on the estimated distance cost, estimated time cost, and estimated energy cost of the next node to be screened, determine the estimated cost from the next node to be screened to the target node, including:

[0041] Perform a weighted sum of the estimated distance cost, estimated time cost, and estimated energy cost of the next node to be screened to obtain the estimated cost from the next node to be screened to the target node.

[0042] In a second aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the stratospheric airship path planning method described in any one of the above.

[0043] In a third aspect, the present application provides 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 stratospheric airship path planning method described in any one of the above.

[0044] In a fourth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the stratospheric airship path planning method described in any one of the above.

[0045] According to the specific embodiments provided by the present application, the following technical effects are disclosed:

[0046] The present application discloses a stratospheric airship path planning method, device, medium and product. First, path planning parameters of the stratospheric airship are obtained; the path planning parameters include: predicted wind field data, airspeed, and the topological structure of the flight area; the topological structure includes multiple nodes, and the nodes are starting nodes, target nodes, obstacle nodes or feasible nodes; the predicted wind field data includes: wind speeds of each grid in the stratosphere at multiple moments updated at set time steps starting from the departure moment, and the wind speeds of each grid at the same moment are equal, and one grid corresponds to one node; then, the departure moment is determined as the 0th wind field update moment, and the moment obtained by adding a set time steps to the departure moment is the ath wind field update moment; the time period from the (b - 1)th wind field update moment to the bth wind field update moment is determined as the bth time period, and the wind speed at the (b - 1)th wind field update moment is determined as the wind speed of the bth time period; b≥1; any time period is determined as the current time period, and the stopping node of the previous time period is determined as the starting node of the current time period; the stopping node of any time period is the last node in the path node set of the time period, and the path node set includes multiple path nodes; wherein, when the current time period is the 1st time period, the stopping node of the previous time period is the starting node; secondly, starting from the starting node of the current time period, based on the path planning parameters, using the improved A* algorithm, path planning is performed on the current time period to obtain the path node set of the current time period; the cost function of the improved A* algorithm is a function of distance cost, energy cost and time cost; finally, during the process of performing path planning on the current time period, it is determined in real time whether the last node in the path node set of the current time period is the target node; if so, the starting node, the target node and each intermediate node are determined as the optimal path node set, and the optimal path is obtained by smoothing the optimal path node set using the B-spline interpolation method, and the stratospheric airship is controlled to reach the target node from the starting node according to the optimal path; the intermediate node is a path node between the starting node and the target node; if not, using the improved A* algorithm, continue to perform path planning on the current time period, update the path node set of the current time period until the current time period ends, update the stopping node of the previous time period to the stopping node of the current time period, update the current time period to the next time period, and return to "starting from the starting node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning on the current time period to obtain the path node set of the current time period". The present application performs separate phased planning on the overall path from the starting node to the target node based on the improved A* algorithm and the predicted wind field data, can adapt to the dynamic wind field in real time, realizes the dynamic path planning of the stratospheric airship, and improves the real-time performance of the stratospheric airship path planning and the adaptability to the wind field. Description of the Drawings

[0047] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0048] Figure 1 Schematic flow chart of the stratospheric airship path planning method provided by an embodiment of the present application;

[0049] Figure 2 Schematic diagram of the changing wind field;

[0050] Figure 3 Schematic diagram of the gravitational field and the repulsive field;

[0051] Figure 4 Schematic diagram of the structure of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0053] The purpose of the present application is to provide a stratospheric airship path planning method, device, medium and product, aiming to achieve the dynamic path planning of the stratospheric airship.

[0054] To make the above objects, features and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0055] In an exemplary embodiment, as Figure 1 shown, a stratospheric airship path planning method is provided, including:

[0056] Step 1: Obtain the path planning parameters of the stratospheric airship.

[0057] Among them, the path planning parameters include: predicted wind field data, airspeed, and the topological structure of the flight area; the topological structure includes multiple nodes, and the nodes are departure nodes, target nodes, obstacle nodes or feasible nodes; the predicted wind field data includes: the wind speeds of each grid in the stratosphere at multiple moments updated at a set time step starting from the departure moment, and the wind speeds of each grid at the same moment are equal, and one grid corresponds to one node.

[0058] Specifically, the starting node is the starting point of the stratospheric airship, and the target node is the ending point of the stratospheric airship.

[0059] As Figure 2 shown, the wind speed in the predicted wind field data is updated at a set time step starting from the departure time, that is, it changes. Considering that the predicted wind field data itself has a certain degree of uncertainty, and the time span of the stratospheric airship during mission execution can often reach dozens of hours. If a fixed predicted wind field data is used as the reference data for the entire path planning process, there will obviously be a large error. Even if an excellent planning algorithm is used to obtain the path, it is difficult to obtain satisfactory results in actual applications. Therefore, dynamic predicted wind field data should be considered.

[0060] Step 2: Determine the departure time as the 0th wind field update time, and the time obtained by adding a set time steps to the departure time is the ath wind field update time.

[0061] Step 3: Determine the time period from the (b - 1)th wind field update time to the bth wind field update time as the bth time period, and determine the wind speed at the (b - 1)th wind field update time as the wind speed of the bth time period; b ≥ 1.

[0062] Step 4: Determine any time period as the current time period, and determine the stop node of the previous time period as the starting node of the current time period.

[0063] Among them, the stop node of any time period is the last node in the path node set of the time period. The path node set includes multiple path nodes; among them, when the current time period is the 1st time period, the stop node of the previous time period is the starting node.

[0064] Step 5: Starting from the starting node of the current time period, based on the path planning parameters, use the improved A* algorithm to perform path planning for the current time period to obtain the path node set of the current time period.

[0065] Among them, the cost function of the improved A* algorithm is a function of distance cost, energy cost, and time cost.

[0066] As an optional implementation manner, Step 5 includes:

[0067] Step 51: For any current path node in the path node set of the current time period, determine the next path node of the current path node according to the principle of the minimum estimated cost of the cost function.

[0068] As an optional implementation manner, in Step 51, the determination process of the next path node after any current path node in the path node set of the current time period includes:

[0069] Step 511: Determine any surrounding feasible node at the current path node as the next node to be screened; the surrounding feasible nodes of the current path node are the feasible nodes among the nodes corresponding to the eight grids other than the current grid in the nine-grid centered on the current grid, and the current grid is the grid corresponding to the current path node.

[0070] Step 512: Determine the surrounding obstacle nodes of the current path node; the surrounding obstacle nodes of the current path node are the obstacle nodes among the nodes corresponding to the eight grids other than the current grid in the nine-grid centered on the current grid.

[0071] Step 513: Obtain the estimated cost from the start node to the next node to be screened at the current time period, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the position coordinates of the current path node, and the potential energy function value of the current path node; when the current time period is the first time period, the estimated cost from the start node to the next node to be screened is 0; when the current time period is not the first time period, the estimated cost from the start node at the current moment to the next node to be screened is determined based on the airspeed, the wind speed in the current time period, the position coordinates of the start node in the current time period, the position coordinates of the next node to be screened, the position coordinates of the obstacle nodes among the nodes corresponding to the eight grids other than the grid corresponding to the penultimate path node in the previous time period in the nine-grid centered on the grid corresponding to the penultimate path node in the previous time period, the potential energy function value of the penultimate path node in the previous time period, and the position coordinates of the penultimate path node in the previous time period.

[0072] Step 514: Determine the estimated cost from the next node to be screened to the target node based on the airspeed, the wind speed in the current time period, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the potential energy function value of the current path node, and the position coordinates of the current path node.

[0073] As an optional implementation manner, step 514 includes:

[0074] Step 5141: Determine an estimated value of the distance cost from the next node to be screened to the target node based on the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, and the position coordinates of the current path node.

[0075] As an optional implementation manner, step 5141 includes:

[0076] Step 51411: Determine the gravitational field of the next node to be screened based on the position coordinates of the next node to be screened and the position coordinates of the target node.

[0077] Specifically, as Figure 3As shown in the figure, a gravitational field is established around the target node to guide the stratospheric airship to navigate towards the target node. The magnitude of the gravitational field is inversely proportional to the distance between the stratospheric airship and the target node. For any node, for example, the calculation formula for the gravitational field of the nth node is:

[0078]

[0079] Where U att (n) is the gravitational field of the nth node; (x n , y n ) is the position coordinate of the nth node, x n is the x-axis component of the position coordinate of the nth node, y n is the y-axis component of the position coordinate of the nth node; (x g , y g ) is the position coordinate of the target node, x g is the x-axis component of the position coordinate of the target node, y g is the y-axis component of the position coordinate of the target node.

[0080] Step 51412: Determine the repulsive field of the next node to be screened based on the position coordinates of the next node to be screened and the position coordinates of the surrounding obstacle nodes.

[0081] Specifically, as Figure 3 shown in the figure, a repulsive field is established around the obstacle node to make the stratospheric airship avoid the obstacle node. The magnitude of the repulsive field is proportional to the distance between the stratospheric airship and the obstacle node. The calculation formula for the repulsive field of the nth node is:

[0082]

[0083] Where U rep (n) is the repulsive field of the nth node; (x o , y o ) is the position coordinate of the obstacle node, x o is the x-axis component of the position coordinate of the obstacle node, y o is the y-axis component of the position coordinate of the obstacle node.

[0084] Step 51413: Determine the potential energy function value of the next node to be screened based on the gravitational field of the next node to be screened and the repulsive field of the next node to be screened.

[0085] Specifically, the calculation formula for the potential energy function value of the nth node is:

[0086] U(n) = U att (n) - ∑U rep (n).

[0087] Among them, U(n) is the potential energy function value of the nth node.

[0088] Step 51414: Based on the potential energy function value of the next node to be screened, the potential energy function value of the current path node, the position coordinates of the next node to be screened, and the position coordinates of the current path node, determine the estimated value of the distance cost from the next node to be screened to the target node.

[0089] Specifically, the calculation formula for the distance cost from the nth node to the target node is:

[0090]

[0091] Among them, L h (n) is the estimated value of the distance cost from the nth node to the target node; m1 is the coefficient of the adjustment ratio; |P n-1 P n | is the distance between the (n - 1)th node P n-1 and the nth node P n ; U(n - 1) is the potential energy function value of the (n - 1)th node.

[0092] Traditional distance cost estimation methods (such as the heuristic distance of the traditional A* algorithm) may fall into local minima, resulting in a non-optimal path. By introducing gravitational and repulsive forces, this problem can be effectively avoided, ensuring the global optimality of the path; and the repulsive force field can be adjusted according to the distance between the stratospheric airship and the high-wind area, thus preventing the stratospheric airship from entering the high-wind area. This makes the path not only the shortest path but also able to avoid dangerous areas in actual navigation.

[0093] Step 5142: Based on the airspeed, the wind speed in the current period, the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period, determine the estimated value of the time cost from the next node to be screened to the target node.

[0094] As an optional implementation manner, Step 5142 includes:

[0095] Step 51421: Based on the airspeed and the wind speed in the current period, determine the ground speed in the current period.

[0096] Specifically, the calculation formula for the ground speed is:

[0097]

[0098] Among them, is the ground speed, that is, the speed of the stratospheric airship relative to the ground; is the wind speed; is the airspeed, that is, the speed of the stratospheric airship relative to the air.

[0099] Step 51422: Determine an estimated value of the time cost from the next node to be screened to the target node based on the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed at the current time period.

[0100] Specifically, considering that stratospheric airships are mostly in a constant-speed cruise state when performing tasks, and even if there are speed changes, they do not switch frequently. Therefore, it can be considered that the ground speed of a stratospheric airship is constant during the expansion movement of one node. The calculation formula for the estimated value of the time cost from the nth node to the target node is:

[0101]

[0102] where, T h (n) is the estimated value of the time cost from the nth node to the target node; is the magnitude of the ground speed.

[0103] Step 5143: Determine an estimated value of the energy cost from the next node to be screened to the target node based on the position coordinates of the current path node, the position coordinates of the next node to be screened, the ground speed at the current time period, and the wind speed at the current time period.

[0104] Specifically, a stratospheric airship can use its airbag to keep its altitude unchanged without consuming energy. In an ideal state, the energy consumed by a stratospheric airship is completely used to overcome the work done by air resistance, and in this process, it follows:

[0105]

[0106]

[0107] where, E h (n) is the estimated value of the energy cost from the nth node to the target node; is the magnitude of the airspeed; F d is the air resistance; ρ is the atmospheric density; A is the windward area of the stratospheric airship.

[0108] Since the wind speed can directly obtain its magnitude and direction according to the wind speed at this position in the wind field, and the ground speed remains constant in the previous assumption, it is more convenient to use and to replace for calculation.

[0109] Therefore, the calculation formula for the estimated value of the energy cost from the nth node to the target node in this application is:

[0110]

[0111] Step 5144: Determine the estimated cost from the next node to be screened to the target node based on the estimated values of the distance cost, time cost, and energy cost of the next node to be screened.

[0112] As an alternative implementation, step 5144 includes:

[0113] Perform a weighted sum of the estimated values of the distance cost, time cost, and energy cost of the next node to be screened to obtain the estimated cost from the next node to be screened to the target node.

[0114] Specifically, the calculation formula for the estimated cost from the nth node to the target node is:

[0115] h'(n) = ω1L h (n) + ω2T h (n) + ω3E h (n).

[0116] Where h'(n) is the estimated cost of the cost from the nth node to the target node; ω1 is the weight of the distance cost; ω2 is the weight of the time cost; ω3 is the weight of the energy cost; ω1 + ω2 + ω3 = 1.

[0117] Step 515: Determine the total estimated cost of the next node to be screened based on the estimated cost from the starting node of the current period to the next node to be screened and the estimated cost from the next node to be screened to the target node.

[0118] Specifically, the calculation formula for the total estimated cost of the nth node, which is the cost function of the improved A* algorithm, is:

[0119] F'(n) = g'(n) + h'(n).

[0120] Where F'(n) is the total estimated cost of the nth node; g'(n) is the estimated cost from the starting node of the current period to the nth node, g'(n) = g'(n par ) + ω1L g (n) + ω2T g (n) + ω3E g (n), L g (n) is the estimated value of the distance cost from the starting node of the current period to the nth node, T g (n) is the estimated value of the time cost from the starting node of the current period to the nth node, E g (n) is the estimated value of the energy cost from the starting node of the current period to the nth node, g'(n par ) is the estimated cost from the starting node of the current period to the parent node of the nth node (i.e., the previous node of the nth node).

[0121] Step 516: Determine the next node to be screened with the minimum total estimated cost as the next path node.

[0122] Step 52: Determine whether the next path node is the target node.

[0123] Step 53: If so, obtain the path node set of the current time period based on the next path node and all path nodes before the next path node in the current time period.

[0124] Step 54: If not, update the current path node to the next path node and return to Step 51.

[0125] Step 6: During the path planning for the current time period, determine in real time whether the last node in the path node set of the current time period is the target node.

[0126] Step 7: If so, determine the departure node, the target node, and each intermediate node as the optimal path node set, and use the B-spline interpolation method to smooth the optimal path node set to obtain the optimal path, and control the stratospheric airship to reach the target node from the departure node according to the optimal path; the intermediate node is the path node between the departure node and the target node.

[0127] Specifically, considering the characteristics of the stratospheric airship with large inertia and large turning radius, there is a problem that the corners of the broken line composed of the optimal path node set are not smooth enough. Using the B-spline interpolation method, introduce the B-spline curve to smooth each path node in the optimal path node set, and follow the following when smoothing:

[0128]

[0129]

[0130] Among them, Path op is the optimal path obtained after smoothing; P i is the control point corresponding to the i-th node; B i,k (z) is the k-th B-spline basis function corresponding to the i-th node; B i,0 (z) is the 0-th B-spline basis function corresponding to the i-th node; τ i is the i-th node; τ i+1 is the (i + 1)-th node; τ i+k is the (i + k)-th node; B i,k-1 (z) is the (k - 1)-th B-spline basis function corresponding to the i-th node; τ i+k+1 is the (i + k + 1)-th node.

[0131] Step 8: If not, use the improved A* algorithm to continue path planning for the current period, update the path node set of the current period until the end of the current period, update the stop node of the previous period to the stop node of the current period, update the current period to the next period, and return to Step 5.

[0132] In an exemplary embodiment, a computer device is provided, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the stratospheric airship path planning method.

[0133] In an exemplary embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the stratospheric airship path planning method is implemented.

[0134] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the stratospheric airship path planning method is implemented.

[0135] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 4 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, a stratospheric airship path planning method is implemented.

[0136] Those skilled in the art can understand that Figure 4 the structure shown in

[0137] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0138] The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0139] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0140] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0141] In this text, specific examples are used to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A stratospheric airship path planning method, characterized in that, The stratospheric airship path planning method includes: Obtaining path planning parameters of the stratospheric airship; the path planning parameters include: predicted wind field data, airspeed, and the topological structure of the flight area; the topological structure includes multiple nodes, and the nodes are departure nodes, target nodes, obstacle nodes, or feasible nodes; the predicted wind field data includes: wind speeds of each grid in the stratosphere at multiple moments updated according to a set time step starting from the departure moment, and the wind speeds of each grid at the same moment are equal, and one grid corresponds to one node; Determining the departure moment as the 0th wind field update moment, and the moment obtained by adding a set time steps to the departure moment is the ath wind field update moment; Determining the time period from the (b - 1)th wind field update moment to the bth wind field update moment as the bth time period, and determining the wind speed at the (b - 1)th wind field update moment as the wind speed of the bth time period; b≥1; Determining any time period as the current time period, and determining the stop node of the previous time period as the start node of the current time period; the stop node of any time period is the last node in the path node set of the time period, and the path node set includes multiple path nodes; among them, when the current time period is the 1st time period, the stop node of the previous time period is the departure node; Starting from the start node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning for the current time period to obtain the path node set of the current time period; the cost function of the improved A* algorithm is a function of distance cost, energy cost, and time cost; During the process of performing path planning for the current time period, real-time judge whether the last node in the path node set of the current time period is the target node; If so, determine the departure node, the target node, and each intermediate node as the optimal path node set, and use the B-spline interpolation method to smooth the optimal path node set to obtain the optimal path, and control the stratospheric airship to reach the target node from the departure node according to the optimal path; the intermediate node is a path node between the departure node and the target node; If not, use the improved A* algorithm to continue performing path planning for the current time period, update the path node set of the current time period until the current time period ends, update the stop node of the previous time period to the stop node of the current time period, update the current time period to the next time period, and return "Starting from the start node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning for the current time period to obtain the path node set of the current time period".

2. The stratospheric airship path planning method according to claim 1, characterized in that, Starting from the start node of the current time period, based on the path planning parameters, using the improved A* algorithm, perform path planning for the current time period to obtain the path node set of the current time period, including: For any current path node in the path node set of the current time period, determine the next path node of the current path node according to the principle of the minimum estimated cost of the cost function; Judge whether the next path node is the target node; If so, a set of path nodes for the current time period is obtained based on the next path node and all path nodes before the next path node in the current time period; If not, the current path node is updated to the next path node, and "for any current path node in the set of path nodes for the current time period, the next path node of the current path node is determined according to the principle of the minimum estimated cost of the cost function" is returned.

3. The stratospheric airship path planning method according to claim 2, characterized in that, The determination process of the next path node after any current path node in the set of path nodes for the current time period includes: Determine any surrounding feasible node of the current path node as the next node to be screened; the surrounding feasible nodes of the current path node are the feasible nodes among the nodes corresponding to the eight grids except the current grid in the nine-grid centered on the current grid, and the current grid is the grid corresponding to the current path node; Determine the surrounding obstacle nodes of the current path node; the surrounding obstacle nodes of the current path node are the obstacle nodes among the nodes corresponding to the eight grids except the current grid in the nine-grid centered on the current grid; Obtain the estimated cost from the start node of the current time period to the next node to be screened, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the position coordinates of the current path node, and the potential energy function value of the current path node; when the current time period is the first time period, the estimated cost from the start node to the next node to be screened is 0; when the current time period is not the first time period, the estimated cost from the start node at the current moment to the next node to be screened is based on the airspeed, the wind speed in the current time period, the position coordinates of the start node in the current time period, the position coordinates of the next node to be screened, the position coordinates of the obstacle nodes among the nodes corresponding to the eight grids except the grid corresponding to the penultimate path node in the previous time period centered on the grid corresponding to the penultimate path node in the previous time period, the potential energy function value of the penultimate path node in the previous time period, and the position coordinates of the penultimate path node in the previous time period; Based on the airspeed, the wind speed in the current time period, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the potential energy function value of the current path node, and the position coordinates of the current path node, determine the estimated cost from the next node to be screened to the target node; Based on the estimated cost from the start node of the current time period to the next node to be screened and the estimated cost from the next node to be screened to the target node, determine the total estimated cost of the next node to be screened; Determine the next path node as the next node to be screened with the minimum total estimated cost.

4. The stratospheric airship path planning method according to claim 3, wherein Based on the airspeed, the wind speed in the current time period, the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, the potential energy function value of the current path node, and the position coordinates of the current path node, determining the estimated cost from the next node to be screened to the target node includes: Determine an estimated value of the distance cost from the next node to be screened to the target node based on the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, and the position coordinates of the current path node; Determine an estimated value of the time cost from the next node to be screened to the target node based on the airspeed, the wind speed in the current period, the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period; Determine an estimated value of the energy cost from the next node to be screened to the target node based on the position coordinates of the current path node, the position coordinates of the next node to be screened, the ground speed in the current period, and the wind speed in the current period; Determine the estimated cost from the next node to be screened to the target node based on the estimated value of the distance cost, the estimated value of the time cost, and the estimated value of the energy cost of the next node to be screened; 5. The stratospheric airship path planning method according to claim 4, characterized in that Determine an estimated value of the distance cost from the next node to be screened to the target node based on the position coordinates of the next node to be screened, the position coordinates of the target node, the position coordinates of the surrounding obstacle nodes, and the position coordinates of the current path node, including: Determine the gravitational field of the next node to be screened based on the position coordinates of the next node to be screened and the position coordinates of the target node; Determine the repulsive field of the next node to be screened based on the position coordinates of the next node to be screened and the position coordinates of the surrounding obstacle nodes; Determine the potential energy function value of the next node to be screened based on the gravitational field of the next node to be screened and the repulsive field of the next node to be screened; Determine an estimated value of the distance cost from the next node to be screened to the target node based on the potential energy function value of the next node to be screened, the potential energy function value of the current path node, the position coordinates of the next node to be screened, and the position coordinates of the current path node; 6. The stratospheric airship path planning method according to claim 4, wherein Determine an estimated value of the time cost from the next node to be screened to the target node based on the airspeed, the wind speed in the current period, the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period, including: Determine the ground speed in the current period based on the airspeed and the wind speed in the current period; Determine an estimated value of the time cost from the next node to be screened to the target node based on the position coordinates of the current path node, the position coordinates of the next node to be screened, and the ground speed in the current period; 7. The stratospheric airship path planning method according to claim 4, wherein Determine the estimated cost from the next node to be screened to the target node based on the estimated value of the distance cost, the estimated value of the time cost, and the estimated value of the energy cost of the next node to be screened, including: Perform a weighted sum of the estimated value of the distance cost, the estimated value of the time cost, and the estimated value of the energy cost of the next node to be screened to obtain the estimated cost from the next node to be screened to the target node.

8. A computer device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the stratospheric airship path planning method according to any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the stratospheric airship path planning method according to any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the stratospheric airship path planning method according to any one of claims 1-7.

Images