Interval Estimation for Continuous-Time Linear Systems With Discrete Measurements

This article investigates interval estimation for continuous-time linear time-invariant systems with discrete measurements. To obtain a reliable interval estimation, a novel interval estimation method is proposed by combining a robust observer gain design approach with an interval analysis method. First, a robust observer synthesis approach is adopted to compute an observer gain to improve the accuracy of the pointwise estimation when the discrete measurements are available. In the case of aperiodic discrete-time measurements, a polytopic model with an additive norm-bounded term is proposed to characterize the uncertainties induced by the time-varying character of the intermeasurement interval times. Then, to cope with these uncertainties, a robust observer design method is introduced. Based on the obtained pointwise estimation, an interval estimation is achieved via an interval-based explicit reachability method. Compared with the existing results, the proposed method relies on nonrestrictive assumptions and provides high estimation performance. Simulation results are presented to illustrate the effectiveness and superiority of the proposed method.