Giant Swing Motion Control of 3-link Gymnastic Robot with Friction around an Underactuated Joint

Abstract

This paper discusses a control method which can stabilize the giant swing motions of 3-link horizontal bar gymnastic robot. A method called Multiple-prediction Delayed Feedback Control(MDFC) proposed by the authors, which has been shown to be effective in control such chaos system, is extended in this paper to experimental gymnastic robot system, taking in account the effect of friction around the link joint. The dynamic of underactuated systems like gymnastic robot shows significant differences in cases of with friction and without friction. However, MDFC considers only the ideal situation without friction. Therefore, a stabilization control method consisting of three kind of control inputs which the one is MDFC for guaranteeing asymptotic stability and the others are used for friction compensation is derived. Numerical simulations and experimental results prove its effectiveness of our proposed method.