A Study on the Brachiation Type of Mobile Robot : 6th Report, Modeling of a Seven-Link Robot and Simulation with Initial Controllers

Abstract

In this paper, we propose a seven-link brachiation robot, which has a structure much like a gibbon. The dynamic equations are derived in a general form and a simulator with a three-dimensional graphical interface is developed. The robot is examined for its potential for brachiation using initial controllers developed for three kinds of fundamental behaviors in brachiation : amplitude control behavior, target-approaching behavior and grip position feedback behavior. The oscillation state of the robot is represented by a radius and an angle of the phase plane. The radius representing oscillation amplitude is controlled by changing the pendulum length of the center of gravity with respect to the phase angle. The phase angle can also be employed for target-approaching to provide desired states. Simulation results show that the proposed robot may successfully achieve brachiation motion with the initial controllers for the three kinds of fundamental behaviors.