Energy based Nonlinear Control of Underactuated Brachiation Robot

This paper studies a type of dynamically moving robot modeling a long armed ape's locomotion which called brachiation robot. Brachiating is the hand over hand swinging locomotion used by various primates, especially the long armed apes, and the manner of moving like a long armed ape is called brachiation. By analyzing the behavior of the long armed ape, which moves from branch to branch swinging its body like a pendulum, the basic principle and brachiating control of the simplified 2-link brachiation robot is studied. In this paper we present the energy based nonlinear control method to control the swing manner of brachiation, and a feed back control law is designed using the Lyapunov stability theory. The target brachiation is an effective locomotion from one bar to another by exchanging kinetic energy with potential energy like a pendulum, which the same as the real long armed ape uses. Finally the experimental results on a 2-link-model brachiation robot show feasibility of the developed controller design scheme.