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NTP-ERSN verification with C5G7 1D extension benchmark and GUI development
Lahdour, M.,El Bardouni, T.,El Hajjaji, O.,Chakir, E.,Mohammed, M.,Al Zain, Jamal,Ziani, H. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.4
NTP-ERSN is a package developed for solving the multigroup form of the discrete ordinates, characteristics and collision probability of the Boltzmann transport equation in one-dimensional cartesian geometry, by combining pin cells. In this work, C5G7 MOX benchmark is used to verify the accuracy and efficiency of NTP-ERSN package, by treating reactor core problems without spatial homogenization. This benchmark requires solutions in the form of normalized pin powers as well as the vectors and the eigenvalue. All NTP-ERSN simulations are carried out with appropriate spatial and angular approximations. A good agreement between NTP-ERSN results with those obtained with OpenMC calculation code for seven energy groups. In addition, our studies about angular and mesh refinements are carried out to produce better quality solution. Moreover, NTP-ERSN GUI has also been updated and adapted to python 3 programming language.
Redouane Chaibi,Hicham El Aiss,Ahmed El Hajjaji,Abdelaziz Hmamed 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.7
This paper investigates the problem of delay dependent stability and H∞ control design with derivatives of membership functions of uncertain Takagi-Sugeno (T-S) fuzzy systems with interval time-varying delay. A model transformation is employed by considering a three-term approximation of delayed state vector. Using Scaled Small Gain (SSG) theorem and fuzzy weighting-dependent Lyapunov functions with some useful slack variables, less conservative robust stability and stabilization criteria are formulated in terms of linear matrix inequalities (LMIs), which can be easily solved by using standard numerical packages. Finally, numerical experiments are presented to illustrate the effectiveness of the proposed method.
Hamdi Gassara,Ahmed El Hajjaji,Mohamed Krid,Mohamed Chaabane 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4
This paper investigates the problems of delay-dependent stability analysis and memory control design of polynomial fuzzy systems with time delay. Using polynomial Lyapunov-Krasovskii functional and slack polynomial matrix variables, delay dependent sufficient stability and stabilizability conditions are derived in terms of sum of squares (SOS) which can be numerically (partially symbolically) solved via the recently developed SOSTOOLS. The main advantage of the proposed design is the reduction of conservatism for three great reasons. The first one is that polynomial matrices are not only dependent on the system state vector but also on the state vector with time delay. The second one is that the design conditions are formulated in delay dependent SOS. It is well known that the delay-dependent conditions are less conservative than those independent of time delay. The third one is that only correlated terms are used in the design of SOS. The simulation and comparison are given to illustrate the lesser conservativeness of the proposed result.
Local Stabilization of Polynomial Fuzzy Model with Time Delay: SOS Approach
Hamdi Gassara,Ahmed El Hajjaji,Fatma Siala,Mohamed Chaabane 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.1
In this paper, a design method of control for Polynomial Fuzzy Models (PFM) with time delay is developed. By using a Polynomial Lyapunov Krasovskii Functional (PLKF) with double integral and by imposingbounds on the derivatives of each state, less conservative sufficient conditions are established to ensure the local stabilityof the closed loop system. Furthermore, a Domain Of Attraction (DOA) in which the initial states are ensuredto converge asymptotically to the origin is estimated. The resulting conditions are formulated in terms of Sum-Of-Squares (SOS) which can be numerically (partially symbolically) solved via the recently developed SOSTOOLS. Some examples are provided to show the effectiveness and the merit of the design procedure.
Erradi Amine,Touhtouh Samira,El Ballouti Abdessamad,Hajjaji Abdelowahed 한국탄소학회 2021 Carbon Letters Vol.31 No.6
In view of the growing need for clean energy, supercapacitors (SC), especially those based on activated carbon (AC) and organic electrolyte are attracting great attention for their theoretically infnite life span. However, they still age much faster than expected due to certain mechanisms. Several researches is being conducted to understand these mechanisms, but so far, the chemical reactions at the phase boundary of the activated carbon electrodes and organic electrolyte have been very unclear. Some pathways have not yet been investigated; there is no research on the reactions that can take place between acetonitrile in the vapor phase and the oxides presented on the surface of activated carbons. For this reason, in this study, divided into two parts, the frst based on a thermal simulation and the second based on an experimental study, we have systematically described the ageing mechanisms by determining the gas-phase reactions that can occur at the electrode–electrolyte interface. On the one hand, a thermal model of a supercapacitor cell using activated carbon and organic electrolyte technology has been developed. This model allowed us to study the temperature distribution of supercapacitors, and thus to determine the thermodynamic parameters related to the phenomena produced at the electrode–electrolyte interface. On the other hand, a thermo-gravimetric analysis coupled with gas phase infrared spectroscopy on the activated carbons of an aged supercapacitor of the same technology as that used in the simulation was carried out. The results obtained made it possible to identify the chemical groups produced by ageing.
Robust Adaptive Controller for the Diesel Engine Air Path with Input Saturation
Samia Larguech,Sinda Aloui,Olivier Pagès,Ahmed El Hajjaji,Abdessattar Chaari 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.10
In this paper, we design an adaptive controller for the diesel engine air path with a priori consideration of actuator saturation effects to regulate the exhaust manifold pressure and the compressor flow rate. The originality of the proposed approach is the integration of an auxiliary system to compensate the saturation effects. Simulation results of the diesel engine air path are given to show the efficiency of the proposed approach.
Dhouha Kharrat,Hamdi Gassara,Ahmed El Hajjaji,Mohamed Chaabane 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.3
This paper concerns the problem of state, fault estimation (FE) and Fault Tolerant Control (FTC) of Takagi-Sugeno (T-S) descriptor systems affected by sensor, actuator and external disturbances simultaneously. An Adaptive Fuzzy Observer is firstly proposed to achieve a simultaneous estimation of descriptor system states, actuator and sensor faults by using the H∞ optimization technique. A FTC is secondly proposed to stabilize the faulty descriptor system. Based on Lyapunov method, stability analysis and design conditions of the resulting closed-loop system are formulated in a set of Linear Matrices Inequalities (LMIs). The adaptive fuzzy observer and the FTC are independently designed, in order to avoid the coupling problem. Accordingly, the observer and controller gains are computed separately by solving a set of LMIs and then used to estimate the unmeasured states, sensor and actuator faults at the same time. Finally, a truck-trailer system application is given to illustrate the validity of the proposed approach.
Design of Robust Fault Detection Observer for Takagi-Sugeno Models Using the Descriptor Approach
Maha Bouattour,Mohammed Chadli,Mohamed Chaabane,Ahmed El Hajjaji 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.5
This paper deals with the design of a robust fault detection observer for a Takagi-Sugeno (T-S) fuzzy model affected by sensor and actuator faults and unknown bounded disturbances simultaneously. An observer based on the technique of descriptor systems is studied. Indeed, by considering faults as auxiliary state variables, both states and faults are estimated simultaneously. In order to guarantee the best robustness to disturbances and sensitivity to faults, the developed observer combine the H__/H_∞ performances. Then, based on Lyapunov method, asymptotic stability conditions are given to design the observer parameters. In order to get convenient and reliable faults estimator in computations, an iterative linear matrix inequality (LMI) algorithm is developed. This algorithm, solved easily using existing numerical tools, allows to minimize influences of disturbances and maximize the ones of faults. Finally, a numerical example is proposed to illustrate the effectiveness of the result.
Friction and wear performance of disc brake pads and pyroelectric energy harvesting
Yassine Tabbai,Amine Alaoui-Belghiti,Reddad El Moznine,Fouad Belhora,Abdelowahed Hajjaji,Abdessamad El Ballouti 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.2
Due to the perpetual development of new technologies in the transportation industry, vehicles become more powerful and faster. As a result, the braking systems have to simultaneous follow this same rate of progression. The brake, a major safety organ, gets significant interest of engineers and researchers. The main purpose of this paper is to present a study based on numerical modelling coupling the thermodynamic and the thermoelectrical behaviours of an automobile brake disc for the prediction of the wear of disc brake pads and the time to be changed, as well as the harvesting of the thermal energy resulting from the braking operation. Firstly, an analysis of the thermal phenomena operating in a brake disc in service (heat fl ow generated by friction, high thermal gradients, temperature rise, and the speed of rotation of the disc) is presented. The proposed modelling is carried out taking into account the influence of different parameters such as the type of braking, the cooling mode, and the design materials. Then, the studies are focused on the use of a smart material for heat recovery due to the contact between the disc and the pads, this material has a capability of converting thermal energy into exploitable electric energy, as a consequence, we can predict the state of health and proper time to change the pads. This study is based on the pyroelectric effect, for a good prediction of the proper time to change the pads. The magnitudes of the voltage generated and the energy density harvested are shown as a function of the pads thicknesses, the speed and the temperature traversed by the pyroelectric material PZT.