3-DOF Trilateral Teleoperation Using a Pair of 1-DOF and 2-DOF Haptic Devices: Stability Analysis

Humans are usually better than autonomous robots in operating in complex environments. In bilateral teleoperation, to take full advantage of the human’s intelligence, experience, and sensory inputs for performing a dexterous task, a possibility is to use the two hands of the user to manipulate two master haptic devices in order to control a slave robot with multiple degrees-of-freedom (DOF); the total DOFs of the two masters are equal to the DOFs of the slave. In this paper, two 1-DOF and 2-DOF haptic robots are considered as the two masters while a 3-DOF robot acts as the slave in a trilateral teleoperation system. It is discussed how such a system can result in better task performance by splitting the various DOFs of a dexterous task between two hands or two users, e.g., during peg-in-the-hole insertion. The stability analysis of such a system is not trivial due to dynamic coupling across the different DOFs of the robots, the human operators, and the physical/virtual environments. Also, the unknown dynamics of the users and the environments exacerbate the problem. We present a novel, straightforward and convenient method for stability analysis of this teleoperation system. Simulation results demonstrate the validity of the approach.