Rapid planning method for drone flight corridors

Abstract

A rapid flight corridor planning method for unmanned aerial vehicles (UAVs) is proposed, primarily based on the operational patterns of UAVs used in material transportation. This method rapidly establishes the latest corridors by first using existing elevation maps to plan the flight area, then employing an optimal path algorithm to find the current best flight path and recording the relevant data. Next, UAVs equipped with laser ranging devices are deployed to update the flight corridor information. Finally, a suitable flight corridor and a stereoscopic visual mapping model are established.

Claims

1. A method for rapid planning of UAV flight corridors, comprising at least the following steps: Step 1: Selecting the start and end points of the corridor based on existing elevation maps in a topographic map database, and setting coordinate points between nodes; Step 2: Using LiDAR to measure the distance between the UAV and the ground to update the flight path in real time, comparing the updated altitude of the flight path with the altitude provided by the existing elevation map to determine if the two altitudes match. If they do not match, proceed to Step 3; if they match, proceed to Step 4; Step 3: If the aforementioned altitude does not match, adjusting the flight altitude by identifying high-risk areas. This identification includes calculating the risk index of the node based on the altitude and slope in the flight path, and comparing the risk index of the node with a preset threshold. If the risk index of the node is less than the preset threshold, proceed to Step 4; if the risk index of the node is greater than or equal to the preset threshold, it is identified as a high-risk area, and the process returns to Step 2; wherein... The formula for determining the high-risk area is as follows: where is the risk index of the node, is the altitude of the node, is the slope of the node, and is the risk adjustment weight, satisfying the value; Step 4: When passing the aforementioned altitude, the flight path weight of the UAV from the node to the node is comprehensively calculated based on the distance weight, altitude weight, and risk index weight. Then, the Dijkstra algorithm is used as the optimal path algorithm for flight path planning. Based on the flight path weight, the set of all possible flight paths between the node is calculated, and several corresponding two-dimensional (2D) planar grid path simulation maps are generated. By updating the shortest distance of the node to obtain the objective function of path optimization, the shortest route of the UAV from the starting point to the destination is calculated. From these 2D planar grid path simulation maps, the best 2D planar grid path simulation map with the shortest route is identified to obtain the current best flight path of the UAV. The relevant information is recorded in the route map database to update the information of the local offline corridor elevation map, and then proceeds to Step 5 and Step 6 respectively; The comprehensive calculation formula for the flight path weight is as follows: Where is the total weight of the flight path PPP, is the distance weight, is the altitude weight, and is the risk index weight; Calculate the set of all possible flight paths between nodes, the formula is: Where is the set of all possible flight paths, and is the flight path weight of the UAV from node to node; and, update the shortest distance of the node using the formula: Where is the shortest distance of the node. If passing through the node can shorten the distance, then update the distance value of the node; Finally, obtain the objective function for path optimization, the formula is: Where is the optimal flight path from the starting point to the ending point; Step 5: Construct a stereoscopic visual map model based on the optimal 2D planar grid path simulation map to generate a corresponding three-dimensional (3D) terrain simulation map; and Step 6: Based on the optimal 2D planar grid path simulation map, convert the path to a three-dimensional coordinate format through spatial coordinate transformation, and the formula for spatial coordinate transformation is as follows: Where is the Earth radius, is the longitude, is the latitude, and is the converted three-dimensional coordinate.

2. The method for rapid flight corridor planning of unmanned aerial vehicles as described in claim 1, wherein, The second step uses the following formula to calculate the distance using a laser: where is the target distance, is the speed of light (approximately), and is the round-trip time of the laser pulse.

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