Nonlinear observer-based approach for cooperative control of networked rigid spacecraft systems

This paper considers the cooperative control problem for a multi-agent agent system composed of rigid spacecraft systems with quaternion-based attitude representation and a dynamic leader system, whose angular velocity is generated from a general nonlinear system. A distributed nonlinear observer is first proposed to estimate the input of the nonlinear leader system, based on which, a nonlinear internal-model-based observer is constructed, capable of estimating nonlinear signals with parametric uncertainty. Then observer-based local controllers are designed to achieve the asymptotic tracking of the leader's attitude and angular velocity, the latter of which is also robust to the uncertain mass property of the rigid spacecraft systems.