Practical L_2 Disturbance Attenuation For Nonlinear Systems

摘要

In this work, a definition of generalized L_2-gain for nonlinear systems, where the gain is considered as a function of the state instead of a (global) constant, is presented. This new notion seems to be adequate to characterize the gain properties of several nonlinear systems which do not posses a uniform L_2-gain property (i.e. the L_2-gain depends on the operating point). Morever, a notion of practical L_2-gain attenuation, which extends the standard definition and parallels(mutatae mutandis) the concepts of practical stability, is also proposed.