Predictive Time Domain Passivity Control For Delayed Teleoperation Using Energy Derivatives

Time domain passivity control deals with the stabilization of haptic interfaces in teleoperation using the notion of passivity directly in the continuous time variables like force and velocity. In a previous work, authors have already shown that this concept can be utilized to stabilize the time-delayed teleoperation by considering the communication channel as an active component and to design passivity controllers for it on master side using a Kalman filter based recursive prediction of slave side energy. However, such a scheme is prone to large corrective impulses generated by passivity controllers as the scheme only comes into action when the net energy goes negative, while on other time instants it stays out of the control loop providing a completely transparent teleoperation. These impulses degrade the performance of teleoperator. It is thus proposed, that the derivative of net energy should also be computed in real-time, and as soon as this term becomes negative, indicating a decline in the net energy, the passivity controllers should immediately compensate this active behavior. Simulation results of the proposed scheme showing very good stability and transparency are presented