Smoother Position-Drift Compensation for Time Domain Passivity Approach Based Teleoperation

Abstract

Despite being one of the most robust methods in bilateral teleoperation, Time Domain Passivity Approach (TDPA) presents the drawback of accumulating position drift between master and slave devices. The lack of position synchronization poses an obstacle to the performance of teleoperation and may prevent the successful accomplishment of such tasks. Several techniques have been developed in order to solve the position-drift problem in TDPA-based teleoperation. However, they either present poor transparency by over-conservatively constraining force feedback or add high impulse-like force signals that can be harmful to the hardware and to the human operator. We propose a new approach to compensate position drift in TDPA-based teleoperation in a smoother way, which keeps the forces within the normal range of the teleoperation task while preserving the level of transparency and the robust stability of energy-based TDPA. We also add a way of tuning the compensator to behave in accordance with the task being performed, whether it requires faster or smoother compensation. The feasibility and performance of the method were experimentally validated. Good position tracking and regularamplitude forces are demonstrated with up to 500 ms round-trip constant and variable delays for hard-wall contacts.

Whole-Body Bilateral Teleoperation of a Redundant Aerial Manipulator

“…Time Domain Passivity Approach (TDPA) [18]- [20] was developed in order to enforce stability of both haptic and bilateral teleoperation setups where velocity and force signals are exchanged. In teleoperation systems, time-delay and package losses introduced by the channel might compromise the overall stability of the system, whereas in haptics instability can be a result of sampling.…”

Multi-DoF Time Domain Passivity Approach Based Drift Compensation for Telemanipulation

“…Despite being able to successfully compensate for the drift, these methods generate force spikes when the compensation action is allowed into the system after drift has been accumulated. In order to achieve position synchronization while keeping the forces within their normal range, a TDPA-based drift compensator was developed by the authors [12]. In that paper, the previously existing compensation methods were adapted to produce smoother signals while removing the drift.…”

Reducing the conservatism of the time domain passivity approach through consideration of energy reflection in delayed coupled network systems

“…Here (equations (26) and (27)), the dissipation of excessive energy is distributed to L2R and R2L direction proportionately to the real power output P R2L 3 (k) and P L2R 4 (k) in the respective direction. Although other distributions are conceivable, the chosen distribution seems most reasonable since it is related to the current output power.…”

“…This behavior results, to some extent, from the admittance type PC that causes a position drift. Note that the authors of [17,18,26] proposed different methods to compensate for the effect of position drift. Here, the concept of [17] was implemented.…”

“…In both approaches, a PF comp architecture was used. Since the research of [17,18,26] showed that position drift compensation can improve the performance of Approach 1, the position drift compensation presented in [17] was applied to Approach 1. This setup allowed the measurement of interaction forces at Agent Λ1 and Λ2.…”