Three-dimensional spatiotemporal cooperative pursuit guidance law based on leader-follower strategy

This paper presents a three-dimensional leader-follower spatiotemporal cooperative guidance method, to address the issue of intercepting incoming small low-altitude unmanned aerial vehicle (UAV) using UAV swarm. A three-dimensional engagement geometry between the UAV and the target is established in the line-of-sight (LOS) coordinate system, to eliminate the small angle assumption and linearization requirement. Based on the LOS coordinate, a finite-time angle-constraint guidance law is designed for the leader UAV, en-abling the leader UAV to intercept the moving target at the desired angle. Based on the multi-agent consensus theory, multiple follower UAVs without airborne seekers form a spherical encirclement formation around the leader. And the center position and radius of the encirclement formation is adaptively regulated according to the current information of UAVs. As a result, simultaneous interception against the target is achieved without estimating time-to-go and avoiding collisions between UAVs. The convergence and stability of the proposed guidance law is proven based on Lyapunov theory. Simulation results demonstrate that the proposed law can simultaneously intercept the target with a spherical encirclement formation.