Robust Impedance Shaping of Redundant Teleoperators with Time-Delay via Sliding Mode Control

摘要

This paper presents a robust impedance shaping controller for teleoperation systems. An integral sliding mode control law (ISM) is employed together with standard robot inverse dynamics to reject disturbances and uncertainties acting on the robot model and obtain an ideal fully-decoupled system. Higher level optimization-based controllers are responsible for enforcing the desired end effector impedance on master and slave manipulators, as well as for solving possible kinematic redundancies and satisfying control constraints. A three-plus-one channel teleoperation architecture is proposed, with an in-depth analysis of its stability and transparency properties in presence of variable communication delays, based on Llewellyn' s absolute stability theorem. Impedance parameters tuning criteria are derived and the proposed scheme performance is compared in simulation with a time-domain passivity approach. The validation of the proposed controller is carried out on a ABB YuMi dual-arm redundant robot, with one arm employed as a master and the other one as a slave device.