Sh. Zak et S. Hui, OUTPUT-FEEDBACK VARIABLE STRUCTURE CONTROLLERS AND STATE ESTIMATORS FOR UNCERTAIN NONLINEAR DYNAMIC-SYSTEMS, IEE proceedings. Part D. Control theory and applications, 140(1), 1993, pp. 41-50
In the paper a new class of output feedback variable structure control
lers and state estimators (observers) for uncertain/nonlinear dynamic
systems with bounded uncertainties and/or nonlinearities are proposed.
No statistical information about the uncertain elements is assumed. A
variable structure systems (VSS) approach together with the geometric
approach to the analysis and synthesis of system zeros are employed i
n the synthesis of the proposed output feedback controllers and state
estimators. The role of system zeros in the output feedback stabilisat
ion and state estimation, using the VSS approach, is discussed. Numeri
cal examples included illustrate the feasibility of the proposed stabi
lisation and state estimation schemes.