This paper formulates and investigates the relative attitude formation problem of a group of rigid-body agents with directed and switching sensing topologies. Each agent can only measure the attitudes of its neighbors from the body-fixed frame of the agent. Based on the axis-angle representation of the error attitude, we present a distributed protocol and then show how to achieve the desired relative attitude formation, provided that the inter-agent topology graph is jointly connected and each relative attitude between agents initially is contained within a geodesic ball of radius less than 2p/3 centered at its desired relative attitude. A numerical example is provided to show the effectiveness of the proposed angular velocity control scheme.
QC 20140120