Robust control for nonlinear dynamic systems

In this paper, a robust control scheme for a class of nonlinear dynamical system is proposed by using output-feedback linearization method. The presented control scheme is based on the VSS. We assume that the nonlinear dynamical system is minimum phase, i.e., the relative degree of the system is p = r(1) + r(2) + ... + r(m) less than or equal to n and zero dynamics is stable. We also assume that the states of zero dynamics are not accessible. It is also shown that the global asymptotically stability is guaranted. And we verified that the proposed control scheme is then applied to the control of a two degrees of freedom (DOF) robotic manipulator with payload.