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 as the result of 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 control the robot arm accurately after a training session of only a few minutes.