Application to Pneumatic Servo System in Bilateral Control Based on Wave Variable

In this paper, we analyzed the stability of a wave-variables-based bilateral control system driven by pneumatic actuators. A pneumatic system is generally a third-order lag system due to the compressibility of gas. Frequency domain passivity of the system is evaluated using scattering matrix. The passivity is numerically confirmed when an appropriate control gain is given. The pneumatic system is nonlinear and can be unstable if the stability analysis is based on frequency domain passivity condition. The simulation results show that the pneumatic bilateral control system is passive.