Stability analysis of delayed 4-channel bilateral teleoperation systems

This paper studies the stability of a delayed 4-channel bilateral teleoperation system based on the passivity framework. Assuming that the operator and the environment are passive systems, the stability of the teleoperation system is reduced to ensuring the passivity of a master control unit (MCU), a slave control unit (SCU), and the time-delayed communication channel. Each of these three blocks is modeled as a 2 × 2 transfer function matrix and passified using our proposed approach in a multi-loop feedback (MLF) structure. We report conditions on the controllers of the 4-channel architecture that are sufficient for passivity of MCU and SCU. Simulation results confirm the validity of these conditions for the stability of the teleoperation system.