A Time Domain Passivity Approach for Asymmetric Multilateral Teleoperation System

Time-domain passivity control (TDPC) is a widely used reliable approach to ensure the stability of the teleoperation systems. Although TDPC almost guarantees the stability of the system, there can be a possibility of instability as TDPC inherits the zero division problem in its conventional control laws. Low value force or velocity signals can lead to zero division in control laws and can be a reason of control failure. A multilateral teleoperation system is much more complex as compared to a bilateral teleoperation system. A multilateral teleoperation system comprises of multiple humans and multiple master and slave robots which results in increased transmission of signals over a communication network. So, it is substantially invaluable for multilateral teleoperation system to have a control scheme which ensures a safe and stable operation. This paper, an extension of our previous work, presents a novel design of TDPC laws for multilateral teleoperation, which not only maintains the passivity of the system for stability but also avoids zero division, thus guaranteeing a stable operation. A new architecture of communication channel is introduced to assign different weights to the masters and slaves depending upon the task requirements. The control strategy proposed in this paper is valid for different numbers of masters and slaves. Simulation and experimental results are presented to demonstrate the efficacy of the control design.