Intermediate-variable-based Non-fragile Estimation for Persistent Dwell-time Switched Systems

This paper mainly investigates the state estimation problem for nonlinear persistent dwell-time switched systems based on an intermediate-variable observer. Firstly, a switching strategy that satisfies the persistent dwell-time constraint is adopted to characterize the switching among nonlinear systems with both uncertainties and external disturbances. Secondly, the intermediate variable technique is used to indirectly estimate the composite disturbances affecting the system. In addition, a non-fragile design scheme is proposed to mitigate potential performance degradation caused by variations in observer gains. Subsequently, based on Lyapunov stability theory, sufficient conditions are derived to guarantee the exponential boundedness of the estimation error system. Finally, the effectiveness of the proposed results is verified through a numerical example.