Output feedback control of a class of nonminimum-phase nonlinear systems

The problem of global stabilization by output feedback is investigated in this paper for a class of nonminimum-phase nonlinear systems. The system under consideration has a cascade configuration that consists of a driven system known as the inverse dynamics and a driving system. It is proved that although the zero dynamics may be unstable, there is an output feedback controller, globally stabilizing the nonminimum-phase system if both driven and driving systems have a lower-triangular form and satisfy a Lipschitz-like condition, and the inverse dynamics satisfy a stronger version of input-to-state stabilizability condition. A design procedure is provided for the construction of an n-dimensional dynamic output feedback compensator. Examples and simulations are also given to validate the effectiveness of the proposed output feedback controller. Copyright (c) 2016 John Wiley & Sons, Ltd.