Reduced-order fast converging observers for systems with discrete measurements and measurement error

We provide novel reduced-order observer designs for continuous-time nonlinear systems with measurement error. Our first result applies to continuous output measurements, and provides observers that converge in a fixed finite time is independent of the initial state when error zero. second under discrete asymptotically rate convergence proportional negative logarithm size sampling interval. satisfy an enhanced input-to-state stability property respect error, which overshoot term only depends on recent history illustrate our using model single-link robotic manipulator coupled DC motor nonrigid joint, pendulum example.