Inverse dynamics-based adaptive control of nonlinear bilateral teleoperation systems

Inverse dynamics controllers deal with nonlinear terms in the robot dynamics in a way that, in the ideal case, the closed-loop system becomes linear and decoupled. Consequently, the performance of the closed-loop systems will be easy to study. Due to such an advantage, inverse dynamics-based adaptive control has been applied to motion control of an uncertain robot in free motion in the literature. However, so far there has been no attempt at simultaneous motion and force control in a master-slave haptic teleoperation system using an adaptive inverse dynamics approach. In this paper, for multi-degree-of-freedom teleoperation systems with nonlinear and uncertain dynamics, adaptive inverse dynamics controllers are incorporated into Lawrence's 4-channel bilateral teleoperation control framework. The resulting high-fidelity control system does not need exact knowledge of the dynamics of the master or the slave. A Lyapunov function is presented to analyze the transparency of the teleoperation system. A simulation study is included to demonstrate the effectiveness of the proposed control method.