Stubborn State and Disturbance Observer Co-Design for Nonlinear Descriptor Systems With δ QC $$ \delta \mathrm{QC} $$ via a Dynamic Event-Triggered Mechanism

This article studies the state and disturbance simultaneous estimation problem for a class of nonlinear descriptor systems with $\delta \text{QC}$ using a dynamic event-triggered mechanism. $\delta \text{QC}$ refers to incremental quadratic constraints, which can provide a unified description of many types of common nonlinear functions. To reduce the negative impact of measurement outliers on the identification estimation, a stubborn state and disturbance observer co-design scheme is proposed for the first time by embedding dynamic saturation output estimation errors. Meanwhile, a dynamic event-triggered mechanism is introduced to avoid the need for continuously available output information, which can reduce the pressure on communication resources. By constructing a Lyapunov function, existence conditions of the stubborn state and disturbance observer are obtained in the form of a convex optimization problem so that the error estimation maintains an acceptable estimation performance. Finally, simulation examples illustrate the universality and stubbornness of the proposed observer.