Portail HAL UHA (Université de Haute-Alsace)
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Multi-scenarios multi-objective predictive controller for lateral control of autonomous vehicles
No full textInternational audiencePath tracking is one of the key functions for autonomous driving. For a safe and comfortable ride, proper assistance should offer high accuracy and smooth tracking. To meet these requirements, Model Predictive Control (MPC) is proving to be a promising solution. However, classic predictive controllers may have limitations in practical challenges when requirements change due to diverse scenarios in a single ride. This work introduces a multi-model predictive control framework that integrates path tracking, operational safety (vehicle handling stability, environmental envelope), and passengers’ comfort (minimum lateral acceleration and jerk) and mediates among these sometimes-competing objectives by prioritizing safety. It can even temporarily reduce tracking quality without compromising safety if this is necessary to enhance passenger comfort. The optimal control problem is solved online using qpOASES and the controller is verified in the IPG CarMaker® high fidelity simulator using a highway exit scenario, demonstrating its ability to balance lane centering and passenger comfort while ensuring safety
Fuzzy Logic-Based Maximum Power Point Tracking Control for Photovoltaic Systems : A Review and Experimental Applications
No full textInternational audienceMaximum power point tracking (MPPT) is an essential technique used to extract the maximum power from a photovoltaic (PV) system. Fuzzy logic-based control is one of the popular methods used for MPPT because it provides excellent performance under varying environmental conditions. The world is now facing a challenge in terms of energy. Solar energy is a key to solve that issue, so it must be optimized. Among the MPPT optimization methods used to improve the photovoltaic modules efficiency, fuzzy logic control (FLC) seems to be the one that is really adapted. However, it has a lot of drawbacks like the complexity of implementation and its performance depends not only on the chosen error, but also on the established inference rules. To solve these problems this method has been modified in various ways. The present work makes a diversified review of MPPT algorithms using fuzzy logic control for PV applications. It is subdivided into three main parts. The first part deals with modified FLC algorithms. The second part deals with FLC algorithms associated with other classical algorithms and the third with MPPT algorithms associated with intelligent methods. The different works analyzed have tested their innovative approaches by simulation and have for the most part validated them by an. It can be noted that the third category is the one that offers a better increase in efficiency even if it has a higher complexity. The second category is more suitable for variable weather conditions and the first one is recommended especially for its very low cost. The suggested asymmetrical fuzzy logic-based MPPT technique uses an asymmetric membership function and a rule-based controller to improve the tracking accuracy and speed. The performance of the suggested technique was evaluated and compared with two existing MPPT techniques. The evaluation was conducted through simulations with MATLAB/Simulink. Overall, the results suggest that the proposed asymmetrical fuzzy logic-based MPPT technique is a promising approach for improving the speed and tracking accuracy MPPT in photovoltaic systems
A novel dual-Z-scheme g-C<sub>3</sub>N<sub>4</sub>/BiOCl/Ag<sub>2</sub>WO<sub>4</sub> heterojunction engineered for sunlight-driven photocatalytic degradation of methylene blue and amoxicillin
No full textInternational audienceThis paper investigates the synthesis of g-C3N4/BiOCl/Ag2WO4 nanocomposites for application in solar energy-driven photodegradation of Methylene Blue dye (MB) and Amoxicillin antibiotic (AMOX). The as-prepared precursor photocatalysts (Ag2WO4, BiOCl, and g-C3N4) and nanocomposite photocatalyst g-C3N4/BiOCl/Ag2WO4 were investigated using a full characterization process to determine their oxidation states (XPS), composition (EDX), morphology (SEM & TEM), structure (FTIR), and crystallinity (XRD). Examination of these characteristics attests to successful synthesis of g-C3N4/BiOCl/Ag2WO4 nanoparticles with enhanced crystallinity. Photocatalysis experiments proved that ternary nanocomposite is highly active towards degrading contaminating molecules, with 98 % for MB and 95 % for AMOX, through redox processes driven by sunlight. Monte Carlo simulation studies reveal that the g-C3N4/BiOCl/Ag2WO4 composite is readily formed, and MB molecules are adsorbed onto its surface in multiple layers, driven by favorable negative adsorption energies.In addition, the recyclability of g-C3N4/BiOCl/Ag2WO4 demonstrates its ability to retain photocatalytic activity across four consecutive cycles. According to active species trapping experiment and UV–vis diffuse reflectance spectroscopy (DRS), a proposed photocatalytic mechanism elucidates the observed enhancement in performance of the g-C3N4/BiOCl/Ag2WO4 system. According to the mechanism, the newly designed dual Z-scheme heterojunction, which promotes the synergistic interaction among the photocatalysts, further accelerates the effective separation and transfer of e−/h+ and accordingly greatly improves the photocatalytic degradation efficiency
Modification of nanoporous filtration membranes by cold plasma polymerisation and application to heavy metals removal
No full textInternational audienceCommercial membranes often exhibit difficulties in rejecting specific ionic species, and especially multivalent cations, due to their usual negative charge. To face this drawback, it is proposed here to functionalize the membrane surface by allylamine plasma polymerization. The surface of a thin film composite membrane with polyamide active layer was modified by depositing poly(allylamine) using cold plasma polymerization. The membranes were first characterized in terms of surface charge (by zeta potential measurements) and mean pore size (by fitting neutral solute rejection curve with a steric hindrance model). Tangential filtrations of solutions containing various cationic pollutants, as well as a foulant molecule, were also conducted with both pristine and modified membranes. Zeta potential measurements show that electrical properties are strongly impacted by polly(allylamine) grafting and isoelectric point is moved towards basic pH when polymerization duration increases. This leads to a shift, from negative to positive membrane charge at natural pH = 6, induced by the positive amine groups grafted at the membrane surface. It turns out that structural properties are also impacted by grafting since the mean pore radius is halved from 2.45 to 1.32 nm and the permeability drops by almost 30% due to polymer growth in the form of a layer of nanometric beads.From filtration of multi-ionic solutions, it can be observed that the changes in membrane properties leads to a strong increase in the rejection of multivalent cations (Ba²⁺, Ni²⁺, Co²⁺ and Cr³⁺) up to 95% . Oppositely, monovalent Li+ and divalent Pb2+, which exhibit negative retentions with the pristine membrane, were weakly rejected by the modified membrane. Considering electrostatic interactions between ions and the positive charge of the modified membrane, the weak impact of modification on lithium rejection was expected, but the odd behaviour of lead is disconcerting. A specific investigation of the ion properties tends to show that usual ion properties cannot explain this behaviour.Finally, the fouling study with BSA shows that the poly(allylamine) deposition does not impact the flux decrease during filtration. However, it allows a more efficient removal of fouling deposit during membrane rinsing, which leads to a lower irreversible fouling and a slightly higher normalized flux.Commercial membrane modification by plasma polymerization appears to be a relevant approach to adjust the membrane surface properties to specific applications of ionic contaminant removal
Synthesis of 3-aminopropyltriethoxysilane-modified Phoenix dactylifera date stone combined with natural clay for adsorption of mercury ions from aqueous solution
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Identifying the Activated Carbon Electrode Aging Pathways in Lithium-Ion Hybrid Capacitors
No full textInternational audienceThis paper reports on several mechanisms of carbon aging in a hybrid lithium-ion capacitor operating with 1 mol L -1 LiPF6 in an ethylene carbonate/dimethyl carbonate 1:1 vol/vol electrolyte. Carbon electrodes were subjected to a constant polarization protocol (i.e., floating) at various voltages and analyzed postmortem via several complementary techniques. The selected protocol was able to simulate the behavior of the real system. Due to the use of metallic lithium as the counter electrode, the influence of battery-like aging mechanisms was assumed to be limited. Our approach focused on the aging mechanisms related to the carbon electrode and determined the structural and chemical changes leading to energy fading in lithium-ion hybrid capacitors. It was shown that an increase in applied voltage not only results in faster system degradation but directs the aging chemistry to different pathways: at moderate voltage values, both capacitance loss and simultaneous increase in resistance predominate. This could be associated with the decrease in carbon surface area and possible pore clogging with by-products of electrolyte degradation and carbon oxidation, disrupting the C sp 2 network. When high voltage is applied, further oxidation of carbon occurs with an increase in measured resistance that leads to the relevant end-of-life criterion to be reached. Detailed postmortem analysis results attributed it to the formation of phenol and ether groups together with electrolyte decomposition products, higher oxidation levels, and structure degradation. It was evidenced that the decrease in the overall carbon conductivity and, in certain cases, modification of the textural properties ultimately aggravates the capacitor performance
Devoir de vigilance : confirmation de la condamnation de La Poste pour insuffisance de son plan de vigilance - CA Paris, Pôle 5 chambre 12, 17 juin 2025, n° 24/05193
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Automatic detection of in-stream river wood from random forest machine learning and exogenous indices using very high-resolution aerial imagery
No full textInternational audienceRiver wood (RW) plays a key role in shaping aquatic and riparian habitats while influencing sediment and water dynamics. This study presents the first automated RW detection model using Random Forest classification and near-infrared aerial imagery on the Meurthe River. By progressively incorporating exogenous indices, the model achieved recall, precision, and F1-scores between 12%-39%, 90%-94%, and 21%-54%, respectively. Validation on the Loire, Doubs, and Buëch rivers confirmed robust detection rates (75.41-86.57%) after filtering. The model also estimated RW characteristics, including length, diameter, area, and volume, with high accuracy post-calibration. These findings demonstrate the potential of remote sensing and AI for RW monitoring, providing an efficient decision-support tool for river management and habitat conservation
