Online tuning of wave impedance in telerobotics

Wave variable based controllers ensure the stability of force-reflecting teleoperators with arbitrary and unknown communication delays. The wave impedance provides a fundamental tuning parameter that allows the designer to trade off performance aspects. We suggest and explore automatically tuning this parameter online to capture the best behavior under varying task configurations. In particular, this strategy adjusts force feedback in order to lower resistance during free space motions and strengthen feedback when in contact. Examining the effects of a variable wave impedance, we develop a generalized wave transformation better suited to online changes and propose a tuning rule to maintain system passivity. Our results are illustrated and confirmed in simulation.