A Study on Dynamic Analyses of Explosion-Proof Pneumatic Robot and Its Stabilization

Abstract

This paper describes the development of an explosion-proof pneumatic robot for use in the chemical or oil industry. For such a robot, the electric part must be completely separated from the combustible gas. In our study, a pneumatic robot is designed in which the robot controller is linked with an actuator by a long pneumatic tube in order to prevent explosion. Then, the robot system is modeled as a nonlinear time-delay system as used in the aerodynamic analyses, and the validity of this model is confirmed through simulation and experimental studies. However, the robot manipula-tor will generate hunting due to the time lag of pneumatic pressure signals. Thus, a two-step PID controller is proposed, which not only prevents hunting but also reduces the steady-state error to zero. The effectiveness of this PID controller has been verified through simulation and experiments. Moreover, the stability margins for the pneumatic tube length are evaluated.