Abstract:

To enhance the ability of general aviation aircraft to adapt to complex terrain environments on plateaus and autonomously avoid threats, a collision-free path planning algorithm (CPPA)-A* suitable for general aviation aircraft is designed. Firstly, a height cost function is introduced on the basis of the traditional A* algorithm to address the issue of height fluctuations in paths, and a two-level safety envelope is consistently applied as the safety warning range throughout. Secondly, when dealing with areas with significant terrain undulations, the repulsive field method in the improved artificial potential field method is employed to optimize the height distribution of path nodes, thereby reducing the impact of height variations on flight. The final path is smoothed through two-level path optimization using Laplacian and Gaussian to reduce the magnitude of the path’s turning changes. The CPPA-A* reduces altitude fluctuations by 65.3% compared to the fast expanding random tree algorithm, shortens the flight path length by 9 331.62 m compared to the three-dimensional A* algorithm, and improves computational efficiency by 39.9%. The results indicate that the proposed algorithm can provide technical support for the research of route planning technology with complex terrain constraints in high-altitude environments.

Key words: collision-free path planning algorithm （CPPA）, two-level safety envelope, improved repulsive field method, two-level path optimization