Recent developments in optimal observer design for dynamic positioning have led to application of contraction analysis. In this paper a theoretical method for nonlinear optimal observer design and a suboptimal observer using a state-dependent Riccati equation approach are presented. The observer will be compared to an existing observer and its properties and performance is discussed. Early obse...

A new observer, namely a cascade observer, for a general class of nonlinear SISO systems was presented by the authors [1]. Inspired by but different from a highgain observer, the cascade observer features a cascade structure and adaptive observer gains. In doing so the cascade observer attempts to overcome some of the typical problems that may pose to a high-gain observer. Based on the cascade ...