Multi-task control of multi-contact manipulators during accidental interactions with robot body

In this paper, the problem of controlling multiple different tasks in various points on the robot body is considered. The proposed approach guarantees the execution of multiple various tasks (force, position and orientation control) in the presence of intentional or accidental interaction with robot body. The control law distinguish between desired and accidental external forces. Magnitude and/or orientation of the forces in the contact points can be controlled while various tasks may be defined and controlled in other contact points in the robot body. Controller-observer algorithm is proposed based on the generalized momentum of the robot. Asymptotically stability of task space errors are proved while a proper estimation of the external torque on robot is available. Performance of the proposed algorithm is confirmed by simulations.