A Two Flow Expression Method of Four-Channel Bilateral Control System with Time Delay and Validation of Model-Free Time Delay Compensator

Abstract

Bilateral control is one of the control methods for teleoperation system. The presence of network delays between a master robot and a slave robot makes the design of bilateral control system challengeable. It seriously deteriorates the performance and possibly makes the system unstable. In this paper, to overcome the destabilization from network delay, the model-free time delay compensator is proposed. The proposed compensator does not utilize time delay model and plant model, but the bilateral control system is stabilized. The stability of the proposed control system is shown by using two flow expression method. Two flow expression method models the master system and the slave system of four-channel bilateral control system as single input and single output system. This method makes the analysis for the stability and the performance of the four-channel bilateral control system simple. The validity of the proposed model-free time delay compensator is confirmed by numerical and experimental results.

A Bilateral Control System to Synchronize with Haptic and Visual Sense for Teleoperation over Network

“…Figure 7 shows the Nyquist plots which are calculated by utilizing two flow expression method (23) . Table 1 shows parameter for this analysis.…”

“…In addition, time delay compensation with model-free time delay compensator (23) and its effect to stability are shown.…”

“…Disturbance observer (DOB) and reaction force observer (RFOB) are implemented in the master robot and the slave robot for robust acceleration control (24) (25) . In (23) .…”

“…3, open-loop transfer function for the bilateral control system without model-free time delay compensator (L w/o ) and those for the bilateral control system with model-free time delay compensator (L w/c ) are calculated as Eqs. (3) and (4) by using two flow expression method (23) . Then, these open-loop transfer functions are decomposed as (5) to (9) for analyzing the stability.…”

“…To overcome the destabilization from network delay, the authors' previous research proposed model-free time delay compensator (23) . The proposed compensator does not utilize time delay model and plant model, but position control and force control are stabilized.…”