Hybrid dead-beat observers for a class of nonlinear systems

TL;DR

This paper introduces a hybrid dead-beat observer design for nonlinear systems linear in unmeasured states, enabling accurate state and signal frequency estimation even with noisy measurements.

Contribution

It presents a novel hybrid observer approach based on strong finite-time observability, applicable to reduced or full-order nonlinear systems.

Findings

Effective state estimation in a batch reactor without precise measurements

Accurate frequency estimation of sinusoidal signals under high noise

Demonstrated robustness of the observer in practical scenarios

Abstract

This paper studies the reduced-order or full-order, dead-beat observer problem for a class of nonlinear systems, linear in the unmeasured states. A novel hybrid observer design strategy is proposed, with the help of the notion of strong observability in finite time. The proposed methodology is applied to a batch reactor, for which a hybrid dead-beat observer is obtained in the absence of the precise measurements of the concentration variables. Moreover, the observer is used for the estimation of the frequency of a sinusoidal signal. The results show that accurate estimations can be provided even if the signal is corrupted by high frequency noise.