Showing papers by "Hassan Hammouri published in 2013"

Observer Design for Uniformly Observable Systems With Sampled Measurements

Abstract: This work considers the problem of observer design for continuous-time systems with sampled output measurements (continuous-discrete time systems). In classical literature and in many applications, the continuous-discrete time extended Kalman filter (EKF) is used in order to tackle this problem. In this work, using a normal form characterizing the class of nonlinear uniformly observable single output nonlinear systems, it is shown that a particular stationary solution of a continuous discrete time Lyapunov equation can be used in order to design a constant high gain observer. Explicit conditions are given to ensure global convergence of the observer. Finally, an illustration of this result is given using an example of a biological process.

Forwarding Design With Prescribed Local Behavior

Abstract: Among the non-linear control techniques, some Lyapunov design methods (Forwarding/Backstepping) take advantage of the structure of the system (Feedforward-form/Feedback-form) to formulate a continuous control law which stabilizes globally and asymptotically the equilibrium. In addition to stabilization, we focus on the local behaviour of the closed loop system, providing conditions under which we can predetermine the behaviour around the origin for Feedforward systems.

Local observer for infinitesimally observable nonlinear systems

Abstract: In this article, we present a local observer based on infinitesimal observability along trajectories. The gain of this observer derives from a dynamical Lyapunov equation. The inputs for which the observer converges are those which render the system observable at each point of the Ω-limit of the unknown trajectory (infinitesimal observability at infinity along trajectories). The performance of the proposed observer is illustrated with an application to DC machine.

Trajectory tracking of bilinear systems using high gain observer

Abstract: This paper proposes a trajectory tracking approach for bilinear systems using high gain observer. The proposed technique is based on the use of orthogonal functions and especially the use of operational integration and product matrices. These operational tools allow the conversion of a bilinear differential state equation into an algebraic one. Arranging and solving the obtained algebraic equation lead to a feedback control law that allows the track of a system trajectory. High gain observer is applied to the controlled system in order to ensure the robust track of system trajectory. The adjusting high gain observer parameter allows to system to track its trajectory despite noise. The proposed method is applied to a cylindrical heat exchanger process that is considered, under some assumptions, as a bilinear system.

Cylindrical heat exchanger trajectory planning and tracking using orthogonal functions

Abstract: This paper proposes a trajectory planning and tracking approach for cylindrical heat exchanger process that is considered, under some assumptions, as a bilinear system. The proposed technique is based on orthogonal functions and especially the use of operational integration and product matrices. These operational tools allow the conversion of a bilinear differential state equation into an algebraic one depending on initial and final conditions. Arranging and solving the obtained algebraic equation lead to an open loop control law that allows the planning of a system trajectory. The parameters setting of the tracking state feedback closed loop control is yielded by considering a reference model characterizing the desired performances. A high gain observer is associated to heat exchanger process in the planning trajectory step and tracking one. A planned open loop control and a state feedback control that ensures tracking of reference trajectory were applied to the system exchanger associated to observer which is subject to noise and disturbance.