Electro-Pneumatic Pressure Servo-Control for a Miniature Robot with Rubber Actuator

This paper described the structure of a flexible miniature robot system which can move in human cavities, it makes inchworm-like movement driven by a 3-DOF pneumatic rubber actuator and holds its positions by air chambers. The driving characteristic models in axial and bending directions of the actuator were set up, and an electro-pneumatic pressure control system for the locomotion of the robot was designed. The nonlinear characteristics of pneumatic pressure-position servo-control system were analyzed, the fluid flow characteristic equation in pipe and the electromagnetic valve on-off characteristic equation were set up. Experiments proved the pressure in all air chambers of robot system can be controlled more accurately by adopting the PWM (Pulse Width Modulation) technique, and the robot could move smoothly through the electro-pneumatic pressure control system. The study is the base of effective control for the locomotion of the miniature pneumatic robot.