Toward Robust Passivity: A Passive Control Implementation Structure for Mechanical Teleoperators

In previous papers, a passive control implementation structure is proposed for mechanical systems interacting with physical environments. The proposed implementation structure enforces robust passivity of the closed-loop system, i.e. passivity is ensured in the presence of inaccurate force sensing and model uncertainties. In this paper, we conduct experiments to validate and demonstrate this robust passivity property of the passive control implementation structure in the context of mechanical teleoperator control. The experiments show that the implementation structure indeed ensures passivity of the closed-loop teleoperator by limiting the amount of energy generated by the control action even in the presence of model uncertainties and master-slave force sensings corrupted with time-delays. Thus, safety and interaction stability of the closed-loop teleoperator are substantially enhanced.