Nonuniform in time state estimation of dynamic systems

In this paper it is shown that, if a time-varying uncertain system is robustly completely detectable, then there exists an estimator for this system, i.e. the state vector of the system can be estimated asymptotically. If the time-varying uncertain system is robustly completely observable, it is shown that there exists an estimator for this system with assignable rate of convergence of the error. Moreover, specialized constructions are developed for the special class of triangular systems.