Hybrid-Type Position and Force Control of Robot Manipulator Using Artificial Rubber Muscle.

Abstract

An artificial rubber muscle has attracted much attention to features of light weight and mechanical flexibility, thus it is anticipated to be applied to a robot which can operate kindly against or with human. However, there are few reports on the multi-d. o. f. manipulator using this actuator. In this study, a hybrid-type position and force control is carried out by using a 2 d. o. f. manipulator comprising this actuator, of which fundamental control performances are investigated. This actuator has a nonlinear characteristic in terms of structure and air compressibility, which makes accurate position control difficult. To cope with these problems, a position controller using a two d. o. f. PID controller is realized by adding a feedforward compensator. As a result, a satisfactory position tracking control performance can be obtained. Also, hybrid control of force control and tracking speed can be accomplished with sufficient accuracy.