Dissipativity and Design of Unknown Input Observers for Nonlinear Systems

Abstract Unknown input observers (UIO) are able to estimate perfectly the state of a system, despite of completely unknown input perturbations. Previous works of the authors have shown that for linear systems the existence of an UIO is equivalent to the possibility of rendering the plant dissipative by output injection. In this paper it will be shown that, under some weak regularity conditions, an UIO can be constructed for nonlinear systems if an error system, build as the difference of the plant and the system with zero unknown input, can be rendered dissipative by output injection.

[1]  Ali Saberi,et al.  Exact, almost and optimal input decoupled (delayed) observers , 2000 .

[2]  P. Müller,et al.  Disturbance decoupled observer design: a unified viewpoint , 1994, IEEE Trans. Autom. Control..

[3]  Jaime A. Moreno,et al.  Existence of unknown input observers and feedback passivity for linear systems , 2001, Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228).

[4]  Zhong-Ping Jiang,et al.  Passivity and disturbance attenuation via output feedback for uncertain nonlinear systems , 1998, IEEE Trans. Autom. Control..

[5]  Jaime A. Moreno,et al.  PASSIVITY AND UNKNOWN INPUT OBSERVERS FOR NONLINEAR SYSTEMS , 2002 .

[6]  Riccardo Marino,et al.  Nonlinear control design , 1995 .

[7]  Jaime A. Moreno,et al.  Unknown input observers for SISO nonlinear systems , 2000, Proceedings of the 39th IEEE Conference on Decision and Control (Cat. No.00CH37187).

[8]  Wassim M. Haddad,et al.  A unification between partial stability and stability theory for time-varying systems , 2002 .

[9]  M. Hautus.  Strong detectability and observers , 1983 .

[10]  A. Isidori,et al.  Passivity, feedback equivalence, and the global stabilization of minimum phase nonlinear systems , 1991 .

[11]  A. Schaft.  L2-Gain and Passivity Techniques in Nonlinear Control. Lecture Notes in Control and Information Sciences 218 , 1996 .

[12]  Hyungbo Shim,et al.  Nonlinear observer design via passivation of error dynamics , 2003, Autom..

[13]  Delin Chu.  Disturbance decoupled observer design for linear time-invariant systems: a matrix pencil approach , 2000, IEEE Trans. Autom. Control..

[14]  A. Isidori.  Nonlinear Control Systems , 1985 .