Robust decentralized control of a fully actuated robot hand
Résumé
This work deals with the robust control of the CEA anthropomorphic hand. A control-oriented strategy for the mechatronic design of the 24-degree-of-freedom robot hand has been pursued. It has led to a minimization of the kinematic couplings between the different finger axes of the motor-to-joint transmissions on the one hand, and a minimization of the nonlinear configuration-based variations of the plant to be controlled on the other hand. Consequently, from the control point of view, that mechanical design puts forward interesting properties, that are particularly relevant when considering practical implementation of controllers for systems with a high number of inputs and outputs. The generalized diagonally dominance of the system simplifies stability conditions for decentralized control. Thus, a decentralized H∞ controller with both feedforward and feedback actions for all flexion/extension and abduction/adduction motions of one finger unit has been successfully embedded into one single DSP board within the hand. The experimental results show that our whole approach has guaranteed high levels of precision and robustness, which, in turn, helps to improve dexterous manipulation skills of robotic hands.