Transparency analysis of motion canceling bilateral control under sensing constraints

Abstract

Motion canceling bilateral control (MCBC) is a method to synchronize motion of a teleoperation robot and a target, while an operator can obtain tactile sensation of the remote target. This system helps the operator by taking a task and reduces his/her workload. Unfortunately, the transparency is deteriorated due to the operational force caused by a dynamic motion of the target. This effect is caused by the discreteness and a delay in external sensors essential for MCBC. However, the relationships between the transparency and those sensing constraints were not clarified yet. Therefore in this research, the frequency characteristics of the transparency for the MCBC are analyzed in the following three basis: type of holds, sampling period, and stiffness of the target. The analytical results suggested following three behaviors in the transparency of the MCBC. · A first order hold showed better performance compared with a zero order hold, but it has a peak gain near the Nyquist frequency · Shorter sampling period improves the performance · Contacting hard target deteriorate the performance The validity of analysis was verified by the experimental results.