Position-Error Based Schemes for Bilateral Teleoperation With Time Delay: Theory and Experiments

The problem of stable bilateral teleoperation with position-error based force feedback in the presence of time-varying possibly unbounded communication delay is addressed. Two stabilization schemes are proposed that guarantee “independent of delay” stability of the teleoperator system. In particular, one of the schemes theoretically allows to achieve an arbitrary high force-reflection gain, which leads to better transparency without sacrificing the stability of the overall system. The stability analysis is based on the input-to-output stable small gain theorem for systems of functional-differential equations. Experimental results are presented, which demonstrate stable behavior of the telerobotic system with time-varying communication delay during contact with a rigid obstacle.