Toward a generalized sub-optimal control method of underactuated systems

In this paper, some experimental results and a performance analysis of a general control methodology for swinging up and stabilizing underactuated two-link robots are presented. The analyzed method ology is based on EulerLagrange dynamics, passivity analysis, and dynamic programming theory. The applied control method preserves the general structure of a suboptimal control approach, while the functional defining a performance index is based on the underactuated system energy. In order to illustrate the presented approach, the swing up and stabilization control of two experimental electromechanical underactuated systems about an unstable equilibrium point are shown. Copyright 2011 John Wiley & Sons, Ltd.