Hassan HAMMOURI
Professeur

Systèmes Non Linéaires et Procédés
Observation et commande des systèmes non linéaires
Bureau 1 Université Claude Bernard Lyon 1, bât 308G ESCPELyon, 43 bd du 11 Novembre 1918 G323 Villeurbanne 69622 France
Téléphone bureau 1: 04 72 43 18 95
Adresse Email 1: hassan.hammouri[A]univlyon1.fr
Bio
date:2016
références bibliographiques:
International Journal of Sciences and Techniques of Automatic control & computer engineering
A class of weakly regular Lpwellposed linear systems
date:2015
références bibliographiques:
European Journal of Control
Nonlinear Observer Based on Cascade Form and Output Injection
date:2015
références bibliographiques:
SIAM Journal on Control and Optimization
On the Admissible Control operators for Linear and Bilinear Systems and the Favard Spaces
date:2014
références bibliographiques:
Bulletin of the Belgian Mathematical Society
Observer Design for Uniformly Observable Systems With Sampled Measurements
This work considers the problem of observer design for continuoustime systems with sampled output measurements (continuousdiscrete time systems). In classical literature and in many applications, the continuousdiscrete 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.
date:2013
références bibliographiques:
IEEE Transactions on Automatic Control
Forwarding Design with Prescribed Local Behavior
Among the nonlinear control techniques, some Lyapunov design methods (Forwarding / Backstepping) take advantage of the structure of the system (Feedforwardform / Feedbackform) 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.
date:2013
références bibliographiques:
IEEE Transactions on Automatic Control
Cylindrical heat exchanger trajectory planning and tracking using orthogonal functions
date:2013
références bibliographiques:
International Journal of Computer Science Issues
Local observer for infinitesimally observable nonlinear systems
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 Ωlimit of the unknown trajectory (infinitesimal observability at infinity along trajectories). The performance of the proposed observer is illustrated with an application to DC machine.
date:2013
références bibliographiques:
International Journal of Control
An observer design for a class of implicit systems
This paper deals with the problem of observer design for a class of implicit nonlinear systems of index one. To solve this problem, an implicit observer which is given by an implicit system is usually used. The implementation of this kind of observer requires an optimization algorithm to solve at each time the algebraic constraints. Alternatively, an explicit observer which is described by an ordinary differential equation can be used. The advantage of this approach is that no optimization algorithm is required. Moreover the observer initialization may be done outside the constraints. In this paper it is shown that, under some conditions, the existence of an implicit observer implies the existence of an explicit one. Then, an explicit observer is given for implicit state affine systems whose dynamic involves an additional nonlinear term depending on the input, the output and the implicit variable.
date:2013
références bibliographiques:
Systems & Control Letters
Observer Design for MIMO NonUniformly Observable Systems
The design of high gain observers is usually based on normal forms of observability. If the system is observable for every input (uniform observability), the gain of the observer does not required a solution to differential equation. For multiple input multiple output (MIMO) nonuniformly observable systems, we give here a sufficient condition that the input must satisfy in order to design an observer. Unlike uniformly observable systems, the observer gain of nonuniformly observable systems is derived from a Lyapunov differential equation.
date:2012
références bibliographiques:
IEEE Transactions on Automatic Control
Output feedback stabilization of a onedimensional wave equation with an arbitrary time delay in boundary observation
The stabilization with time delay in observation or control represents difficult mathematical challenges in the control of distributed parameter systems. It is wellknown that the stability of closedloop system achieved by some stabilizing output feedback laws may be destroyed by whatever small time delay there exists in observation. In this paper, we are concerned with a particularly interesting case: Boundary output feedback stabilization of a onedimensional wave equation system for which the boundary observation suffers from an arbitrary long time delay. We use the observer and predictor to solve the problem: The state is estimated in the time span where the observation is available; and the state is predicted in the time interval where the observation is not available. It is shown that the estimator/predictor based state feedback law stabilizes the delay system asymptotically or exponentially, respectively, relying on the initial data being nonsmooth or smooth. Numerical simulations are presented to illustrate the effect of the stabilizing controller.
date:2012
références bibliographiques:
ESAIM: Control, Optimisation and Calculus of Variations
Optimal time switching control for multireaction batch process
This paper presents an approach for solving minimal time problems for biological batch models with switching controls. Multireaction processes operated in a sequence of operating modes are considered, where the control variable is the switch between different operating modes. In order to determine the optimal switching instants that minimize the final time to reach the target, a reachability analysis and a study of dynamical properties are first investigated. This leads to a reduced model and the characterization of reachable switching sequences. Optimization tools are then used to determine the optimal switching instants. Copyright © 2009 John Wiley & Sons, Ltd.
date:2010
références bibliographiques:
Optimal Control Applications and Methods
High Gain Observer for Structured MultiOutput Nonlinear Systems
In this note, we present two system structures that characterize classes of multiinput multioutput uniformly observable systems. The first structure is decomposable into a linear and a nonlinear part while the second takes a more general form. It is shown that the second system structure, being more general, contains several system structures that are available in the literature. Two high gain observer design methodologies are presented for both structures and their distinct features are highlighted.
date:2010
références bibliographiques:
IEEE Transactions on Automatic Control
Model predictive control during the primary drying stage of lyophilisation
During the primary drying stage of pharmaceutical solutions in vial, the sublimation front is the boundary between the dried and frozen layers that moves from the top of the vial to its bottom. While only few online measures are available, it is an important variable to control. This paper deals with the online partial differential equation modelbased predictive control of the sublimation front position, assuming two strategies based on various availability of measurement used in the feedback loop. Through the MPC@CB control software, the robustness of the controller with respect to the main model parameter uncertainty is shown.
date:2010
références bibliographiques:
Control Engineering Practice
Unknown input observer for state affine systems: A necessary and sufficient condition
The problem of designing an unknown input observer for linear systems and its application to fault detection is widely studied in the literature. For nonlinear systems, only subclasses of nonlinear systems and sufficient conditions have been stated. In this paper an unknown input observer design for state affine systems is considered. Based on the geometric approach, a necessary and sufficient condition is given for the existence of an unknown input observer.
date:2010
références bibliographiques:
Automatica
Trajectory Planning and Tracking of Bilinear Systems Using Orthogonal Functions
date:2010
références bibliographiques:
Nonlinear Dynamics and Systems Theory
Development of a High Gain Observer for InLine Monitoring of Sublimation in Vial Freeze Drying
Inline monitoring of the primary drying of the lyophilization process of a pharmaceutical product in vials is addressed in this article. A soft sensor (observer) based on the high gain concept is designed to this purpose. The proposed observer combines the physical measure of the frozen product temperature at the bottom of the vial with a simplified mathematical model of the process. This approach allows the continuous estimation of the entire temperature profile of the product and the monitoring of the state of progression of the primary drying phase. The main issues arising in the design of this observer are discussed. A detailed and experimentally validated monodimensional model is used as a source of measured data, in order to compare and validate by means of numerical simulations the results provided by the soft sensor. Finally, the performance of the high gain observer is compared with that of a Kalman filter–based observer previously proposed for the same process, evidencing the advantages of the high gain approach.
date:2010
références bibliographiques:
Drying Technology
New algorithm for observer error linearization with a diffeomorphism on the outputs
date:2009
références bibliographiques:
Automatica
Two Global Stabilizability Results for Homogeneous Systems From a Local Stabilizability Assumption
date:2009
références bibliographiques:
IEEE Transactions on Automatic Control
date:2009
références bibliographiques:
Chemical Engineering Research and Design
This paper is focused on the monitoring of the primary drying phase of the lyophilisation process of pharmaceuticals in vial. Monitoring is required to ensure that the maximum temperature of the product is maintained at a safe value in order to avoid denaturation, and the position of the moving front of sublimation has to be monitored since its evolution gives the state of progression of the primary drying. Furthermore, the information coming from the monitoring system, which includes the estimation of the transport coefficients, can be used in a control loop designed to minimise the drying time beside ensuring product quality.
To this purpose, a softsensor (observer) has been developed, based on the extended Kalman filter algorithm: it requires a model of the process (a simplified model is used in order to reduce the computational load) and some physical measurements (in this case the temperature of the product at the bottom of the vial, that can be measured by a thermocouple). The main issues arising in the design of this observer have been discussed. A detailed monodimensional model experimentally validated has been used at first to compare the results provided by the observer by means of numerical simulations, and then the results obtained in a pilot freezedryer are shown.
date:2009
références bibliographiques:
Chemical Engineering Research and Design