Convergence Analysis of Bilateral Teleoperation with Constant Human Input

In this paper the problem of bilateral teleoperation is studied for a class of human operator models that are not guaranteed to be passive. Specifically, the hard contact scenario is addressed where the human operator applies a constant force on the master robot and the slave robot interacts with the environment, which is modeled as a spring-damper system. In the delay free case, when the master/slave robots are coupled using the PD control strategy, the nonlinear master-slave teleoperation system is shown to be asymptotically stable. If the environment stiffness is known, then the steady state position of the master and slave robots is predicted. In the case of network delay and for a range of the proportional coupling gains, we demonstrate that the master/slave velocities asymptotically converge to the origin and the positions asymptotically converge to a non-zero equilibrium. Simulations results are also presented to verify the proposed results.