Adaptive Control for Nonlinear Teleoperators With Uncertain Kinematics and Dynamics

Abstract

The problem of controlling bilateral teleoperation systems in the presence of uncertain kinematics and dynamics is studied in this paper. Control algorithms and adaptive laws are developed to address the impediment of imprecise measurement resulting from when the slave robot grips a tool with unknown grasping point and orientation. We first demonstrate that with the utilization of the proposed adaptive laws, the teleoperation system is stable and the position tracking is guaranteed even if there are dynamic and kinematic uncertainties. Due to the end-effector velocity being difficult to obtain, an alternative control algorithm that does not incorporate task-space velocity information is developed. The issue of asymmetric constant communication delays in the teleoperation system is studied by Lyapunov-Krasovskii theorem. In the presence of external forces, we prove that all signals in the proposed teleoperation systems are bounded, and that force feedback is proportional to the tracking errors. Numerical simulations and experiments are performed to demonstrate the efficacy of the developed teleoperation systems.