Analysis and control of a rubbertuator arm

Abstract

The control of light-weight compliant robot arms is cumbersome due to the fact that their Coriolis forces are large, and the forces exerted by the relatively weak actuators may change in time due to external (e.g., temperature) influences. We describe and analyse the behaviour of a light-weight robot arm, the SoftArm robot. It is found that the hysteretic force-position relationship of the arm can be explained from its structure. This knowledge is used in the construction of a neural-network based controller. Experiments show that the network is able to accurately control the robot arm after a training session of only a few minutes.