Second order oscillatory system parameter estimation

In the absence of noise (or other uncertainty in measurement), the state vector of a deterministic, full state estimator can be made to systematically converge to the state vector of the system under observation. The above is true when the as reflected in the observer, is “perfect”. When the modeling of the system under observation is less than perfect, the convergence characteristics of the observer are, in some manner, modified. A study of the behavior of the state estimator in the presence of errors in the plant model is usually undertaken. In contrast, a study of the estimation of the modified plant by the means provided in the information which may be gleaned from the modification in the convergence characteristics is undertaken. In this paper, the modified plant is determined by using the “system-observer pair” error dynamics