Adaptive Task-Space Regulation of Rigid-Link Flexible-Joint Robots with Uncertain Kinematics

Chao Liu (1) , Chien Chern Cheah (2) , Jean-Jacques E. Slotine (3)

1 DEXTER - Robotique médicale et mécanismes parallèles
2 EEE - School of Electrical and Electronic Engineering
3 MIT - Massachusetts Institute of Technology

In this paper, an adaptive control scheme is proposed for the regulation problem of rigid-link flexible-joint (RLFJ) robots with uncertain kinematics. Existing research works in literature on RLFJ robot control assume exact knowledge of the kinematics of robot, and no result that can deal with kinematics uncertainty in RLFJ robot has been proposed so far. This paper presents the first study addressing this problem. The adaptive control scheme proposed can deal with the kinematics uncertainty and uncertainties in both link and actuator dynamics of the RLFJ robot system. A nonlinear observer is designed to avoid the use of acceleration due to the fourth-order overall dynamics. Asymptotic stability of the closed-loop system is shown and sufficient conditions are presented to guarantee the stability. Simulation results are provided to illustrate the effectiveness of the proposed control method.

Domaines: Robotique [cs.RO]

Chao Liu, Chien Chern Cheah, Jean-Jacques E. Slotine. Adaptive Task-Space Regulation of Rigid-Link Flexible-Joint Robots with Uncertain Kinematics. Automatica, 2008, 44, pp.1806-1814. ⟨10.1016/j.automatica.2007.10.039⟩. ⟨lirmm-00366215⟩