Publications Scientifiques
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Item Design of Sliding Mode Control Applied to Inverted Cart-Pendulum for Good Stability Performances(2025) Miloudi, Lalia; Toubal Maamar, Alla Eddine; Elamri, Oumaymah; Benabdallah, TassaditThis paper proposes a resilient sliding mode control (SMC) strategy for the stabilization of a cart-pendulum system, tackling significant issues in nonlinear control, including parametric uncertainties and external disturbances. The suggested solution uses a two-step process: first, an open-loop energy-based swing-up to lift the pendulum, and then a closedloop SMC phase to keep it stable. The designed controller uses a saturation function to reduce chattering, which is different from methods that depend on linearized models or complicated gain tuning. The simulation results show that the accuracy is very high, with settling times of about 5 seconds for the pendulum angle and 7 seconds for the cart position. The controller works well even when the system mass and disturbances change by 10%, as long as the cart can only move ±0.5 m and the control forces can only be ±10 N. Stability is reached from the most unfavorable initial condition, the pendulum's downward-hanging position, with a steady-state error of under 1% in essential state variables. This work offers a computationally efficient and adaptive solution, appropriate for real-time applications in robotics and aerospace where resilience to nonlinear dynamics and uncertainty is essential.Item Numerical study of unsteady flow regime in a natural gas pipe(Politechnica University of Bucharest, 2023) Benzerhouda, Amar; Boucetta, Rachid; Khelifi Touhami, Mohamed Salah; Kessal, MohandIn this study, isothermal gas flow characteristics in a long pipeline are monitored and controlled using two mathematical models and the finite difference approach. These models, which take into account continuity, motion, and the equation of state, are based on one-dimensional nonlinear partial differential equations. Results are consistent with the body of literature, supporting their applicability in the present. Higher inclinations have a noticeable impact on output flow rates when examining the effects of pipe inclination on gas flow under similar pressure. A significant contribution of this work is the analysis of stabilization time across inclinations, which reveals pressure shifts and flow steadying after 5000 s. These findings are useful for the energy sector because they help pipeline operators and engineers maintain a safe, effective gas flow.Item Enhancing air compressors multi fault classification using new criteria for Harris Hawks optimization algorithm in tandem with MODWPT and LSSVM classifier(SAGE, 2023) Rahmoune, Chemseddine; Amine Sahraoui, Mohammed; Gougam, Fawzi; Zair, Mohamed; Meddour, IkhlasThe evolution of industrial systems toward Industry 4.0 presents the challenge of developing robust and accurate models. In this context, feature selection plays a pivotal role in refining machine learning models. This paper addresses the imperative of accurate fault diagnosis in industrial systems, focusing on air compressors. These systems, vital for efficient operations, demand early fault detection to prevent performance degradation. Conventional methods often encounter challenges due to the occurrence of similar failure patterns under comparable conditions. To address this limitation, our approach delves into a more complex scenario, where air compressors operate under diverse fault conditions. This study introduces novel feature selection criteria achieved through a fusion of the Maximal Overlap Discrete Wavelet Packet Transform (MODWPT), the Harris Hawks Optimization (HHO) algorithm, and the Least Squares Support Vector Machine (LSSVM) classifier. The synthesis of these components aims to bolster the multi-fault diagnosis accuracy and stability for each fault class. The evaluation focuses on key statistical metrics—minimum, maximum, mean, and standard deviation. Experimental outcomes underscore the method’s superiority over traditional feature selection techniques. The approach excels in accuracy and stability, particularly across various fault categories, affirming the efficacy and resilience of the new criteria. The symbiotic integration of MODWPT, HHO, and LSSVM within our framework highlights its potential to elevate classification performance in the realm of industrial fault diagnosis.Item Design and robust performance analysis of Low-Order approximation of fractional PID controller based on an IABC algorithm for an automatic voltage regulator system(MDPI, 2022) Idir, Abdelhakim; Canale, Laurent; Bensafia, Yassine; Khettab, KhatirIn this paper, a low-order approximation (LOA) of fractional order PID (FOPID) for an automatic voltage regulator (AVR) based on the modified artificial bee colony (ABC) is proposed. The improved artificial bee colony (IABC) high-order approximation (HOA)-based fractional order PID (IABC/HOA-FOPID) controller, which is distinguished by a significant order approximation and by an integer order transfer function, requires the use of a large number of parameters. To improve the AVR system’s performance in terms of transient and frequency response analysis, the memory capacity of the IABC/HOA-FOPID controller was lowered so that it could fit better in the corrective loop. The new robust controller is named the improved artificial bee colony (IABC) low-order approximation (LOA)-based fractional order PID (IABC/LOA-FOPID). The performance of the proposed IABC/LOA-FOPID controller was compared not only to the original ABC algorithm-tuned PID controller, but also to other controllers tuned by state-of-the-art meta-heuristic algorithms such as the improved whale optimization algorithm (IWOA), particle swarm optimization (PSO), cuckoo search (CS), many optimizing liaisons (MOL), genetic algorithm (GA), local unimodal sampling (LUS), and the tree seed algorithm (TSA). Step response, root locus, frequency response, robustness test, and disturbance rejection abilities are all compared. The simulation results and comparisons with the proposed IABC/LOA-FOPID controller and other existing controllers clearly show that the proposed IABC/LOA-FOPID controller outperforms the optimal PID controllers found by other algorithms in all the aforementioned performance testsItem Novel robust control using a fractional adaptive PID regulator for an unstable system(Institute of Advanced Engineering and Science, 2022) Bensafia, Yassine; Idir, Abdelhakim; Khettab, Khatir; Akhtar, Muhammad Saeed; Sarwat, ZahraRecent advances in fractional order calculus led to the improvement of control theory and resulted in the potential use of a fractional adaptive proportional integral derivative (FAPID) controller in advanced academic and industrial applications as compared to the conventional adaptive PID (APID) controller. Basically, a fractional order adaptive PID controller is an improved version of a classical integer order adaptive PID controller that outperformed its classical counterpart. In the case of a closed loop system, a minor change would result in overall system instability. An efficient PID controller can be used to control the response of such a system. Among various parameters of an instable system, the speed of the system is an important parameter to be controlled efficiently. The current research work presents the speed control mechanism for an uncertain, instable system by using a fractional-order adaptive PID controller. To validate the arguments, the effectiveness and robustness of the proposed fractional order adaptive PID controller have been studied in comparison to the classical adaptive PID controller using the criterion of quadratic error. Simulation findings and comparisons demonstrated that the proposed controller has superior control performance and outstanding robustness in terms of percentage overshoot, settling time, rising time, and disturbance rejectionItem On abstract Cauchy problems in the frame of a generalized Caputo type derivative(DergiPark, 2023) Bourchi, Soumia; Jarad, Fahd; Adjabi, Yassine; Thabet, Abdeljawad; Mahariq, IbrahimIn this paper, we consider a class of abstract Cauchy problems in the framework of a generalized Caputo type fractional. We discuss the existence and uniqueness of mild solutions to such a class of fractional differential equations by using properties found in the related fractional calculus, the theory of uniformly continuous semigroups of operators and the fixed point theorem. Moreover, we discuss the continuous dependence on parameters and Ulam stability of the mild solutions. At the end of this paper, we bring forth some examples to endorse the obtained resultsItem A new model for communities' detection in dynamic social networks inspired from human families(Inderscience, 2020) Djerbi, Rachid; Amad, Mourad; Imache, RabahNowadays, social networks have been widely used by different people for different purposes in the world. The discovering of communities is a widespread subject in the space of social networks analysis. Many interesting solutions have been proposed in the literature. However, most solutions have common problems: the stability and the community structures quality. In this paper, we propose a new model to find communities based on a new concept called 'large families'. This model will be used, to motivate a community detection strategy to identify and effectively monitor the evolution of dynamic communities. We propose a compromise between the stability and the quality metrics. We apply our model on a real social network of the karate club of Zachary. Also, we describe experiences of our model on a large scale network of Enron's email data set as broader Benchmark Network. Simulations results show that our proposed model is globally satisfactory.Item Energy Down-Conversion Cs3Cu2Cl5 nanocrystals for boosting the efficiency of UV photodetector(2021) Liu, Chengjun; Wang, Lixi; Fang, Fan; Zhao, Zihan; Pan, Jiangyong; Akram, Javed Akram; Bin Shafie, Suhaidi; Zair Talaighila, Razika; Li, Qing; Zhao, Zhiwei; Wu, Jun; Zhu, Zhuoya; Lei, Wei; Zhang, Xiaobing; Chen, JingZero-dimension (0-D) lead halide perovskite nanocrystals (NCs) have attracted a sight of interest in the field of optoelectronic devices due to their outstanding properties, such as high photoluminescence quantum yield (PLQY) and size- and composition-controlled tunable emission wavelengths. However, the toxicity of lead (Pb) element in the lead perovskite NCs is the bottleneck for the commercial application of perovskite NCs. Herein, we report a facile ligand-assisted synthesis to achieve lead-free Cs3Cu2Cl5 NCs with a high PLQY of ∼70% and good stability against environmental oxygen/moisture as a promising down-conversion material. It has good merits of high PLQY and large Stokes shift (∼300 nm) originated from the effect of Jahn–Teller distortion and self-trapped excitons (STEs). Furthermore, the Cs3Cu2Cl5 NCs embedded composite films (NCCFs) were utilized to enhance the ultraviolet (UV) response of silicon (Si) photodetectors. External quantum efficiency (EQE) measurements show that the UV response can be greatly improved from 3.3 to 19.9% @ 295 nm based on NCCFs combined with Si photodiodes. Our work offers an effective approach to develop highly efficient and stable lead-free Cs3Cu2Cl5 NCs for the application in the solar-blind UV photodetectorItem Rheological and flow behavior of water-in-oil Pickering emulsions stabilized with organo-hectorite clay(Elsevier, 2021) Merad, B.; Bekkour, K.; François, P.; Gareche, M.; Lawniczak, F.The rheological and flow behaviors of Pickering emulsions are studied as a function of their water concentration. The studied emulsions are water-in-gasoil inverse emulsions stabilized with organo-hectorite clay. An in-line emulsion preparation was performed and a novel emulsification system was used. The emulsification system was tested and confirmed before performing pipe-flow measurements. A stress-controlled rheometer was used to study the rheological behavior of organoclay stabilized inverse emulsions. It was found that the emulsions exhibited a shear thinning with yield stress non-Newtonian rheological behavior and that the flow curves were well correlated using the Herschel-Bulkley model. Pressure loss and axial velocity measurements were studied to investigate the pipe-flow behavior of the emulsions. Axial velocity of the fluids was measured using an Ultrasonic Pulsed Doppler Velocimeter. It was shown that, up to 50 wt% water mass concentration, an exponential increase of yield stress and viscosity values is noticed, and the phase inversion point is not reached. In the range of the applied flow rates, turbulence took place only in the case of the lowest water cut (0 wt%). The Herschel-Bulkley rheological parameters were used to simulate the pipe-flow behavior of the studied fluids, and showed a satisfactory correlation with the in-line measurements. Furthermore, wall shear stress and velocity profiles were used to study the short-, medium-, and long-term stability of the emulsions. © 2021 Elsevier B.V.Item Rheological and flow behavior of water-in-oil Pickering emulsions stabilized with organo-hectorite clay(Elsevier, 2021) Boutheina, Merad; Bekkour, Karim; Pierre, François; Gareche, MouradThe rheological and flow behaviors of Pickering emulsions are studied as a function of their water concentration. The studied emulsions are water-in-gasoil inverse emulsions stabilized with organo-hectorite clay. An in-line emulsion preparation was performed and a novel emulsification system was used. The emulsification system was tested and confirmed before performing pipe-flow measurements. A stress-controlled rheometer was used to study the rheological behavior of organoclay stabilized inverse emulsions. It was found that the emulsions exhibited a shear thinning with yield stress non-Newtonian rheological behavior and that the flow curves were well correlated using the Herschel-Bulkley model. Pressure loss and axial velocity measurements were studied to investigate the pipe-flow behavior of the emulsions. Axial velocity of the fluids was measured using an Ultrasonic Pulsed Doppler Velocimeter. It was shown that, up to 50 wt% water mass concentration, an exponential increase of yield stress and viscosity values is noticed, and the phase inversion point is not reached. In the range of the applied flow rates, turbulence took place only in the case of the lowest water cut (0 wt%). The Herschel-Bulkley rheological parameters were used to simulate the pipe-flow behavior of the studied fluids, and showed a satisfactory correlation with the in-line measurements. Furthermore, wall shear stress and velocity profiles were used to study the short-, medium-, and long-term stability of the emulsions