Development of Power-Assist Robot Arm using pneumatic rubbermuscles with a balloon sensor

The present paper describes a power-assist robot arm that uses pneumatic artificial rubber muscles (PARMs) covered with exoskeleton suits to mimic the motion of biarticular muscles. One robot arm uses a single PARM, which assists the wrist and elbow joint of the user. This robot arm is linked to a waist belt through a suspender-like structure of three PARMs. PI control (Proportional Integral control), which is based on the pressure value from a balloon sensor, is used to achieve accurate power-assist motion, and the present study focuses on the motions associated with lifting an object. In order to evaluate the validity of the proposed power-assist robot arm, skin surface electromyography (EMG) signals of forearm muscles are measured during a lifting task and a follow-up questionnaire survey is conducted.