Development of a Robot Arm System Using High-damping Pneumatic Artificial Rubber Muscle

Introduction Pneumatic artificial rubber muscle (PARM) is a pneumatically driven actuator that provides mechanical effects similar in principle to those of muscle contraction. PARM is a novel actuator that has a high weight-power ratio and maximum contraction over the nominal length is 20%. As shown in Figure 1 , PARM is composed of a rubber tube impregnated with fibers. Teleoperation of pneumatic robots is desired in the fields of surgery, rehabilitation therapy, and rescue activities[1]. In our research, firstly, we developed a four-Degree-of-Freedom (DoF) pneumatic robot arm system utilizing 9 pieces of PARMs. Then, we developed basic technique of teleoperation with internet and the developed robot arm system[2]. In robot arms utilizing PARMs, however, oscillation tends to arise under external disturbance or prolonged load bearing. In order to solve this problem, we have focused on the use of a rubber bellows as a damper for this purpose, in the form of high-damping PARMs (HD-PARMs). We constructed an antagonistic drive system with an inertial load with one-DoF by incorporating two of these HD-PARMs and compared its damping effects to those of conventional PARMs. We also modeled each system component and developed a nonlinear numerical simulator to verify its effectiveness.