Two robust nonlinear controllers along with a nonlinear observer have been developed in this study to control a 1D nonlinear flexible spacecraft. The first controller is based on dynamic inversion, while the second one is composed of dynamic inversion and µ-synthesis controllers. The extension of dynamic inversion approach to flexible spacecraft is impeded by the non-minimum phase characteristi...

This paper presents the robust design for chaotic cryptosystems. The cryptosystem combines cryptograph with chaotic synchronization. The hyperchaotic signals are synchronized between the encrypter and the decrypter based on observer gains. The technique of linear matrix inequality (LMI) is applied to determine the observer gains. A theorem has been proposed to guarantee the robust stabilization...

Abstract: This paper investigates the problem of robust observer design for a class of nonlinear stochastic systems with state delays and time-varying normbounded parameter uncertainties. The nonlinearities are assumed to satisfy the global Lipschitz conditions and appear in both the state and measured output equations. The purpose is to design a nonlinear observer ensuring mean square asymptot...

This paper presents new results concerning the observer design for wide classes of nonlinear systems with both sampled and delayed measurements. By using a small gain approach we provide sufficient conditions, which involve both the delay and the sampling period, ensuring exponential convergence of the observer system error. The proposed observer is robust with respect to measurement errors and...

The observer design problem for a class of cell population balance models, describing the time evolution mass density distribution function and substrate concentration in continuous-stirred tank bioreactor with irregular discrete-time measurements is considered. model consists partial integro-differential equation coupled an ordinary differential equation. Using theory impulsive systems suffici...

In this paper, H∞ controller is synthesized for networked systems subject to random transmission delays with known upper bound and different occurrence probabilities in the both of feedback (sensor to controller) and forward (controller to actuator) channels. A remote observer is employed to improve the performance of the system by computing non-delayed estimates of the sates. The closed-loop s...

A robust control scheme is proposed for a class of systems with uncertainty and time delay based on disturbance observer technique. A disturbance observer is developed to estimate the disturbance generated by an exogenous system, and the design parameter of the disturbance observer is determined by solving linear matrix inequalities (LMIs). Based on the output of the disturbance observer, a rob...