Coordinated Control Strategies for a Space Robot

Abstract

This thesis work presents an analysis of the functional differences between various coordinated control strategies for space manipulators, focusing primarily on fuel efficiency. First, a comparison between a standard free-flying controller and novel momentum-based controllers is conducted in order to demonstrate the advantages of the latter approaches. Then, since the considered schemes can suffer performance degradation due to the presence of singularities, the momentum-based method is further extended with a singularity avoidance potential that exploits the full actuation of the system. Thanks to this extension, the whole space robot can be imagined as a "flying end-effector", with the rest of the system executing only a manipulability optimization sub-task and avoiding rigid positioning of the base. This leads to a new paradigm for space robot control, inverting the typical conception of space robots, conventionally seen as a satellite plus an arm payload.