On State Observers for Nonlinear Systems: A New Design and a Unifying Framework
For control engineers, this provides a more general and unified approach to nonlinear observer design, though the improvement is incremental.
The paper proposes a new observer design for nonlinear systems that generalizes two existing methods, extending their applicability, and shows that these designs fit within a unified framework of immersion and invariance observers, with simulations demonstrating superior performance.
In this paper we propose a new observer design technique for nonlinear systems. It combines the well-known Kazantzis-Kravaris-Luenberger observer and the recently introduced parameter estimation-based observer, which become special cases of it---extending the realm of applicability of both methods. A second contribution of the paper is the proof that these designs can be recast as particular cases of immersion and invariance observers---providing in this way a unified framework for their analysis and design. Simulation results of a physical system that illustrates the superior performance of the proposed observer compared to other existing observers are presented.