Path planning of plant protection UAV based on improved A* algorithm under wind conditions

Abstract

In order to improve safety and reduce energy consumption, a path planning method for the transition of plant protection unmanned aerial vehicles (UAVs) in mountainous and hilly terrain between different plots based on improved A* algorithm was proposed. According to the height of three-dimensional terrain information, a raster voxel map was built. The search space was determined by assigning weights to each grid. The wind cost was introduced into the actual cost function to improve the algorithm. Different weight parameters were set for distance cost and wind cost. Simulation experiments were carried out in the fixed wind field and the variable wind field respectively to obtain the track length and flight time of path planning. The simulation results showed that compared with the classic A* algorithm, the improved A* algorithm could save 9.76%, 7.22% and 11.4% in trajectory, energy and time at the maximum under the condition of fixed wind. Under the condition of variable wind field, the maximum trajectory, energy and time saving percentage was 27.6%, 33.1% and 26.2% respectively compared with the classic A* algorithm. The proposed algorithm could effectively plan a safe and reliable three-dimensional flight path, which provided an effective method for better application of plant protection UAVs in complex hilly terrain. Keywords: A* algorithm; Path-planning; wind vector DOI: 10.33440/j.ijpaa.20200304.125 Citation: Sun G H, Fang X F, Zhu L C, Yuan Y W, Zhao B, Han Z H. Path planning of plant protection UAV based on improved A* algorithm under wind conditions. Int J Precis Agric Aviat, 2020; 3(4): 31–38.