Search results for: Elhassen Benfriha

Authors: Jalal Eddine Benmansour, Khouane Boulanoir, Nacera Bekhadda, Elhassen Benfriha

Abstract:

This paper introduces a novel composite control approach that addresses the challenge of stabilizing the three-axis attitude of a flexible satellite in the presence of vibrations caused by flexible appendages. The key contribution of this research lies in the development of a disturbance observer, which effectively observes and estimates the unwanted torques induced by the vibrations. By utilizing the estimated disturbance, the proposed approach enables efficient compensation for the detrimental effects of vibrations on the satellite system. To govern the attitude angles of the spacecraft, a proportional derivative controller (PD) is specifically designed and proposed. The PD controller ensures precise control over all attitude angles, facilitating stable and accurate spacecraft maneuvering. In order to demonstrate the global stability of the system, the Lyapunov method, a well-established technique in control theory, is employed. Through rigorous analysis, the Lyapunov method verifies the convergence of system dynamics, providing strong evidence of system stability. To evaluate the performance and efficacy of the proposed control algorithm, extensive simulations are conducted. The simulation results validate the effectiveness of the combined approach, showcasing significant improvements in the stabilization and control of the satellite's attitude, even in the presence of disruptive vibrations from flexible appendages. This novel composite control approach presented in this paper contributes to the advancement of satellite attitude control techniques, offering a promising solution for achieving enhanced stability and precision in challenging operational environments.

Keywords: attitude control, flexible satellite, vibration control, disturbance observer

Procedia PDF Downloads 85

Authors: Chala Elhassen

Abstract:

City planning and urban management seem more complex our days compared to past times. The interaction of many factors both endogenous and exogenous made more difficult the urban fact. The city has changed status with the demographic bulge. It passed the primary status meeting limited requirements to a multidisciplinary status marked by the diversity of needs. These increase with the increase in population and living standard. Our era is marked by urbanization, complex phenomenon that develops both in industrialized countries in those of the third world. Human concentrations increasingly have significant multiplier effects on the social and economic structure of a region or a country. On the whole, the issue of urban planning revolved around questions related firstly to the understanding of the phenomena of urbanization; and also in search of the most appropriate ways to ensure control, the efficiency and consistency of the urbanization process. Urban planning remains an ambiguous area that mixes scientific contributions, technical, artistic, administrative and legal in varying proportions. What is the founder of specificity is that it always presupposes the existence of a will to act, itself supported by a thorough knowledge of will.

Keywords: urbanization, urban planning, management, industrialized countries

Procedia PDF Downloads 474

Authors: A. Boumedine, K. Benfriha, S. Lecheb

Abstract:

Manufacturing methods for products and structures made of composite materials reduce the number of parts and integrate technical functions, this advantage of composite materials leads to a lot of innovation but also to a reduction of costs and a gain in quality. A material has attributes: its density, it’s resistance, it’s cost, it’s resistance to corrosion. For the design of a product, a certain profile of these attributes is required: low density, resistance removed, low cost. The problem is then to identify this attribute profile and to compare it with those of the materials, in order to find the one that comes closest. The aim of this work is to demonstrate the feasibility of characterizing a mini turbine made of 3D printed fiber-filled composite material by the process of additive manufacturing, then compare the performance of the alloy turbine with the composite turbine according to the results of the simulation by Abaqus software.

Keywords: additive manufacturing, composite materials, design, 3D printer, turbine

Procedia PDF Downloads 131

Authors: Y. Benabid, K. Benfriha, V. Rieuf, J. F. Omhover

Abstract:

This paper describes an approach to create custom concepts for innovative products; this approach describes relations between innovation tools and Computer Aided Design environment (use creativity session and design tools). A model for the design process is proposed and explored in order to describe the power tool used to create and ameliorate an innovative product all based upon a range of data (cloud points) in this study. Comparison between traditional method and innovative method we help to generate and put forward a new model of the design process in order to create a custom Ankle Foot Orthosis (AFO) in a CAD environment in order to ameliorate and controlling the motion. The custom concept needs big development in different environments; the relation between these environments is described. The results can help the surgeons in the upstream treatment phases. CAD models can be applied and accepted by professionals in the design and manufacture systems. This development is based on the anatomy of the population of North Africa.

Keywords: ankle foot orthosis, CAD, reverse engineering, sketch

Procedia PDF Downloads 453

Authors: O. Adjoul, A. Feugier, K. Benfriha, A. Aoussat

Abstract:

In general, issues related to design and maintenance are considered in an independent manner. However, the decisions made in these two sets influence each other. The design for maintenance is considered an opportunity to optimize the life cycle cost of a product, particularly in the nuclear or aeronautical field, where maintenance expenses represent more than 60% of life cycle costs. The design of large-scale systems starts with product architecture, a choice of components in terms of cost, reliability, weight and other attributes, corresponding to the specifications. On the other hand, the design must take into account maintenance by improving, in particular, real-time monitoring of equipment through the integration of new technologies such as connected sensors and intelligent actuators. We noticed that different approaches used in the Design For Maintenance (DFM) methods are limited to the simultaneous characterization of the reliability and maintainability of a multi-component system. This article proposes a method of DFM that assists designers to propose dynamic maintenance for multi-component industrial systems. The term "dynamic" refers to the ability to integrate available monitoring data to adapt the maintenance decision in real time. The goal is to maximize the availability of the system at a given life cycle cost. This paper presents an approach for simultaneous optimization of the design and maintenance of multi-component systems. Here the design is characterized by four decision variables for each component (reliability level, maintainability level, redundancy level, and level of monitoring data). The maintenance is characterized by two decision variables (the dates of the maintenance stops and the maintenance operations to be performed on the system during these stops). The DFM model helps the designers choose technical solutions for the large-scale industrial products. Large-scale refers to the complex multi-component industrial systems and long life-cycle, such as trains, aircraft, etc. The method is based on a two-level hybrid algorithm for simultaneous optimization of design and maintenance, using genetic algorithms. The first level is to select a design solution for a given system that considers the life cycle cost and the reliability. The second level consists of determining a dynamic and optimal maintenance plan to be deployed for a design solution. This level is based on the Maintenance Free Operating Period (MFOP) concept, which takes into account the decision criteria such as, total reliability, maintenance cost and maintenance time. Depending on the life cycle duration, the desired availability, and the desired business model (sales or rental), this tool provides visibility of overall costs and optimal product architecture.

Keywords: availability, design for maintenance (DFM), dynamic maintenance, life cycle cost (LCC), maintenance free operating period (MFOP), simultaneous optimization

Procedia PDF Downloads 116