Disturbance decoupling of Affine nonlinear singular systems

The problem of disturbance decoupling is considered for a class of nonlinear singular control systems. An algorithm is developed, and a coordinate change is introduced such that the control systems can be expressed in a simple form. A feedback control law is then constructed, which ensures the closed loop system has a unique solution without impulses, and its output is unaffected by disturbance. Sufficient and necessary conditions for the existence of such a feedback are derived.