Control-Oriented Design and Robust Decentralized Control of the CEA Dexterous Robot Hand

This study presents the optimized design and robust control strategies for the CEA dexterous hand. A key design feature relies on integrated modular units, for which the tendon routing minimizes kinematic and static coupling between the different finger axes in the motor-to-joint transmissions. Using single-input/single-output control schemes for the mechanically quasi-decoupled system is particularly relevant when considering practical implementation of controllers for systems with a high number of inputs and outputs. Consequently, analysis of the relative gain array puts forward interesting properties in terms of axes decoupling. In particular, stability conditions are easily respected due to the generalized diagonally dominant property of the resulting plant. Decentralized controllers for both flexion/extension and abduction/adduction motions of one finger unit have been successfully embedded into one single DSP board. The controllers are synthesized using two-degree-of-freedom H-infinity structure with both feedforward and feedback actions. They have guaranteed high levels of precision and robustness, which, in turn, helps to improve dexterous manipulation skills of robotic hands.