A speed-gradient-based method to passify nonlinear discrete-time systems

Author:	Navarro-Lopez Eva Maria, Instituto Mexicano del Petroleo, Mexico
Topic:	2.3 Non-Linear Control Systems
Session:	Input-to-State Stability and Passivity
Keywords:	Discrete-time systems, Nonlinear systems, Energy control, Passive elements, Feedback stabilization

Abstract

This paper proposes a method in order to render passive nonlinear affine-in-control discrete-time systems. The methodology is based on the discrete-time version of the speed-gradient (SG) algorithm. For the application of the SG algorithm, quasi-V-passive and feedback quasi-V-passive systems are introduced. Two kinds of feedback laws rendering the system locally quasi-V-passive are obtained: a dynamic one and a static one. The passification methodology is applied to two examples. Some frequency-domain properties of the feedback transformed system are highlighted for the linear example.