Distributed Relative Attitude Formation Control of Multi-agent Systems with Directed Topology

In this paper, a relative attitude formation problem is formulated and investigated for multi-agent systems with a directed sensing topology. In the formulation, every rigid-body agent can get its own angular velocity and measure the attitudes and angular velocities of its neighbors from its body-fixed frame. A distributed protocol is proposed with the help of axis-angle representation. Then it is shown to achieve the desired relative attitude formation when the inter-agent topology graph contains a directed spanning tree and initial relative attitudes between agents are contained within geodesic balls of radius 2 pi/3 with the corresponding desired relative attitudes for the agents as the centers.