Position and force control of a robot by means of round-belt twist-actuation generating contraction forces

Abstract

This paper introduces a novel robotic joint mechanism composed of antagonistically twisted round-belt actuator, which has multiple small-diameter round-belts in antagonistic location around the joint. This joint mechanism is developed by emulating muscle structure of human upper limbs, and can be activated by twisting each round-belt that is made of polyurethane materials. Especially, this paper shows position and force control by means of the proposed twisted round-belt actuators with traditional P/PI controllers. We clearly demonstrate that contact force on tip of the robot is able to follow desired sinusoidal trajectory with no errors by means of straightforward algorithm on the basis of voltagecontrolled robot hardware. Through these experiments, we explain intrinsic characteristics of twisted round-belt actuator system and advantages of the structure in control performance.