Interval estimation for continuous-time Lipschitz nonlinear systems via novel observer design and ellipsoidal analysis

This manuscript introduces a two-step interval estimation approach for continuous-time Lipschitz nonlinear systems, utilizing robust observer design and ellipsoidal analysis. First, the peak-to-peak performance index is adopted to design a novel robust observer with more freedom, attenuating the influence of the uncertainties. Subsequently, interval estimation is achieved by ellipsoidal analysis of an auxiliary error dynamic system, further enhancing the estimation accuracy. Finally, we verify the merit and effectiveness of our approach through comparative numerical simulations.