Analysis of electric-free pneumatic circuits based on logic circuit and its application

Abstract

A McKibben-type pneumatic actuator (MPA) is a type of soft actuator. Several attempts have been made to control robots mechanically driven by pneumatic actuators, and several robotic movements have been realized. Air-driven pneumatic circuits are among the methods proposed for mechanical control. Previous studies confirmed that pneumatic circuits can generate various patterns of self-excited oscillations. These self-excited oscillations can be used for periodic motion of robots with MPAs. To enhance the control of robots with MPAs, it is necessary to analyze the mechanism of the behavior generated by pneumatic circuits. In this study, we analyze the behavior of self-excited oscillations in two types of pneumatic circuits from previous studies by considering them as logical circuits. Consequently, the mechanism by which these pneumatic circuits generate periodic motion was clarified, and the actual behavior was theoretically supported. In addition, we designed a new pneumatic circuit that enabled the robot to walk based on the results of the theoretical analysis as well as verified its motion.