A high level decentralized tracking algorithm for three manipulators subject to motion constraints

This paper considers a tracking problem for three manipulators grasping a rigid object. The control objective is to coordinate the movements of the manipulators using local information in order to align the object attitude with a desired rest attitude and the object position with a time parameterized reference trajectory. The object rigidity is modelled as a constraint on the motion of the end-effectors saying that the distance between any pair of end-effectors must be constant in time. The control law consists of a rotational part and a translational part. The translational part also incorporates a linear observer of the reference trajectory. We prove stability and illustrate the system dynamics by simulation.