Coupling-based methods to design feedback controllers and observers for nonlinear descriptor systems

This paper presents a new approach for analysis and controller design for nonlinear descriptor systems. Thereby, we assume that the descriptor system is given in semi-explicit form and has a continuously differentiable solution, which are very mild assumptions and are fulfilled for most practical applications. Based on the known coupling controller design we transfer the analysis and synthesis from the descriptor system to an equivalent system in state-space form. Methods like dynamic and static input-output decoupling, input-output linearization, model-based feedforward-controller design, zero dynamics, exact descriptor linearization, linear time variant Riccati control, and causal observer design have been introduced based on the coupling procedure [9]. In the following, we summarize the new approach and an algorithm to compute the required state-space system. Additionally, a short introduction how to use it for decoupling control, Riccati control, and causal observer design is given. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)