Radial pole path approach for fast response of affine constrained nonlinear systems with matched uncertainties

This article proposes a novel robust feedback linearization control scheme for affine uncertain nonlinear systems subject to matched uncertainties and constraints on the control input. In this method, instead of placing the linearized system poles at exact locations, radial paths in the open left-hand plane are selected to freely move the poles so as to enhance as much as possible the speed of response while guaranteeing satisfaction of input signal constraints. The stability of our proposed method is analyzed by means of the multivariable circle criterion and the Kalman-Yakubovich-Popov lemma. Simulation results demonstrate how the method significantly increases the speed of response compared to fixed pole placements.