%0 Journal Article %T Robust integral %A Ahmed Toumi %A Ammar Zemzemi %A Mohamed Kamel %A Mondher Farza %J Transactions of the Institute of Measurement and Control %@ 1477-0369 %D 2019 %R 10.1177/0142331218791227 %X This paper addresses the problem of state estimation and sensor fault reconstruction conjointly for a class of nonlinear systems with time-varying uncertainties for which the nonlinear characteristic satisfies the Lipschitz circumstance. A hybrid approach based on an integral observer and sliding-mode theory has been proposed in order to model sensor fault as a virtual actuator one. For the augmented model, the observer matching condition is not satisfied. To overcome this problem, a new method, which improves the design approach and enhances the rapidity of the fault estimation convergence, has been proposed. The fault estimation error effect is minimized by integrating the H ¡Þ disturbance attenuation level. The proposed design is formulated and derived as a linear matrix inequality problem. Parameters of this observer are calculated through the linear matrix inequality technique. The proposed method has been validated through an example of a single-link manipulator robot. Simulation results show that this approach can estimate the state and the sensor fault successfully, despite the time-varying uncertainties and the presence of unknown inputs %K Sensor fault %K H¡Þ approach %K nonlinear observer %K time-varying uncertainty %K linear matrix inequality %U https://journals.sagepub.com/doi/full/10.1177/0142331218791227