Mechanism and control of mechatronic system with higher degrees of freedom

We introduce two types of dexterous locomotion robots and their controller design approaches. One is a simplified two-link robot ‘‘Brachiator II’’. This is an example of an underactuated system where a robot mechanism has higher degrees of freedom than actuators. The desired motions are encoded as the output of a target dynamical system inspired by the pendulum-link motion of an ape’s brachiation. The other is a monkey-type robot ‘‘Brachiator III’’ which achieves a more dexterous motion with 13 degrees of freedom. The desired motion is generated in an empirical learning process by a learning algorithm and an intelligent structure, in which the learning algorithm adjusts the coordination levels of some primitive motions in order to generate the desired motion. This is an example of a redundant mechanism. We discuss the advantages of these two design approaches. # 2004 Elsevier Ltd. All rights reserved.