Discrete space-based route planning for rotary-wing UAV formation in urban environments

The route planning problem for rotary-wing UAV formation is studied in discrete urban environments. First, a discrete-space consensus algorithm (DSCA) integrating asynchronous planning and grouping mechanism is developed to make the rotary-wing UAVs converge to the desired formation. Then the DSCA is combined with the improved rapidly-exploring random tree (IRRT) algorithm to enable the rotary-wing UAV formation to avoid the obstacles. Finally, the time information of waypoints is complemented by resolving the conflicts among multiple rotary-wing UAVs, thus reducing the rotary-wing UAVs' time gap of reaching the destinations. The proposed method extends the original consensus theory in the discrete space and for the obstacle avoidance issue. Also, it is valid in the route planning problem for rotary-wing UAV formation considering the real urban environments.