Achieving High Transparency in Bilateral Teleoperation Using Stiffness Observer for Passivity Control

In this paper a new approach is developed that increases transparency in bilateral teleoperation. We define a stiffness observer which detects hard contact instant by analyzing the generated force in the slave side to activate a passivity controller. This approach uses passivity based idea of monitoring energies flowing in and out of the teleoperator. It improves performance of previous works by eliminating instability in transition to hard contact. It also provides a more general and less conservative approach to passivity control of teleoperated systems. The performance of the new approach has been investigated through simulation results