Decentralized cooperative attitude tracking using Modified Rodriguez Parameters

In this paper, the problem of decentralized cooperative attitude tracking based on relative attitude information is considered in the context of deep space spacecraft formation flying. We use Modified Rodriguez Parameters for attitude representation due to its non-reduction. We first present a cooperative attitude tracking control law such that the attitudes and angular velocities of all spacecraft track their references. Then we extend the result to three different cases. In the first case, we use a passivity approach to derive a control law without angular velocity measurements, which is of significance for applications with low-cost configurations of spacecraft. In the second case, to relax the special connection condition given in the original control design, we obtain a locally asymptotical stability condition for any undirected connected communication topology. In the third case, we consider cooperative attitude tracking in the presence of a dynamic communication topology.