A method of real-time coordination of redundant muscles for multi-DOF robot joints

The strand-muscle actuator (StMA) easily realizes joint angle/stiffness control, even for multi-DOF joints, by antagonistic actuator installation on the joint. The actuator is suitable for complex and flexible motions in spite of their simple mechanism. This work is concerned with an StMA-based robot arm (StMA-RArm), a human-arm-like robot manipulator using StMAs. Its shoulder part realizes failure tolerant 3-DOF joint angle/stiffness control with redundant muscles. For smooth and dexterous motions real-time cooperative muscle tension control is necessary. In this article the mechanism and cooperative control scheme of the StMA- RArm are presented. The Vibrant Particle Swarm Optimization is introduced to solve time-variant optimization problems. And it is then successfully applied to the online coordination of redundant muscles.