2017 年 21 巻 6 号 p. 291-296
In this paper, we develop a nonlinear observer by applying a pseudo-formal linearization method of the polynomial type to both state and measurement equations for nonlinear systems. The given nonlinear system is linearized into an augmented linear system by pseudo-formal linearization based on the Taylor expansion. Furthermore, an augmented measurement vector that consists of polynomials of measurement data is introduced and is transformed into an augmented linear one by the pseudo-formal linearization. A linear system theory is applied to these linearized systems to design a new nonlinear observer. Numerical experiments indicate that the performance of the presented method is more improved than by the previous method.