Adaptive coordination control of bilateral teleoperators with time delay

Bilateral teleoperators, designed within the passivity framework using concepts of scattering and two-port network theory, provide robust stability against constant delay in the network and velocity tracking, but cannot guarantee position tracking in general. In this paper we fundamentally extend the passivity based traditional architecture to guarantee position and force tracking in the face of offset of initial conditions, environmental contacts and packet losses in the network. We propose a novel coordination architecture which uses state feedback to define a new passive output for the master and slave robots containing both position and velocity information. A passive coordination control is also developed, which uses the new outputs to kinematically lock the master and slave robots. For effective extension to practical applications, an adaptive version of the scheme is also developed. Simulation results are presented which demonstrate the effectiveness of the proposed architecture.