Energy efficiency in discrete-manufacturing systems: insights, trends, and control strategies

Since the depletion of fossil energy sources, rising energy prices, and governmental regulation restrictions, the current manufacturing industry is shifting towards more efficient and sustainable systems. This transformation has promoted the identification of energy saving opportunities and the development of new technologies and strategies oriented to improve the energy efficiency of such systems. This paper outlines and discusses most of the research reported during the last decade regarding energy efficiency in manufacturing systems, the current technologies and strategies to improve that efficiency, identifying and remarking those related to the design of management/control strategies. Based on this fact, this paper aims to provide a review of strategies for reducing energy consumption and optimizing the use of resources within a plant into the context of discrete manufacturing. The review performed concerning the current context of manufacturing systems, control systems implemented, and their transformation towards Industry 4.0 might be useful in both the academic and industrial dimension to identify trends and critical points and suggest further research lines.Peer ReviewedPreprin

Integrated Environmental Process Planning for the Design & Manufacture of Automotive Components

Advanced Product Quality Planning (APQP) logic is widely used by manufacturers for the design and manufacture of automotive components. Manufacturers are increasingly finding difficulties to incorporate environmental considerations in the broad range of products that they manufacture. Therefore, there is a need for a systematic method for environmental process planning to evaluate product configurations and their associated environmental impact. The framework and models discussed in this paper can deal with a variety of product characteristics and environmental impacts through a selection of Environmental Performance Indicators (EPIs) for a final product configuration. The framework and models have been applied in a real-life application and have proven that changes in product design or process selection can reduce the product's environmental impact and increase process efficiency. Hence, manufacturers can use the framework and models during the Advanced Product Quality Planning (APQP) process to benchmark each product variation that they manufacture in a standardised manner and realise cost saving opportunities

DFM synthesis approach based on product-process interface modelling. Application to the peen forming process.

Engineering design approach are curently CAD-centred design process. Manufacturing information is selected and assessed very late in the design process and above all as a reactive task instead of being proactive to lead the design choices. DFM appraoches are therefore assesment methods that compare several design alternatives and not real design approaches at all. Main added value of this research work concerns the use of a product-process interface model to jointly manage both the product and the manufacturing data in a proactive DFM way. The DFM synthesis approach and the interface model are presented via the description of the DFM software platform

Multi-agent framework based on smart sensors/actuators for machine tools control and monitoring

Throughout the history, the evolutions of the requirements for manufacturing equipments have depended on the changes in the customers' demands. Among the present trends in the requirements for new manufacturing equipments, there are more flexible and more reactive machines. In order to satisfy those requirements, this paper proposes a control and monitoring framework for machine tools based on smart sensor, on smart actuator and on agent concepts. The proposed control and monitoring framework achieves machine monitoring, process monitoring and adapting functions that are not usually provided by machine tool control systems. The proposed control and monitoring framework has been evaluated by the means of a simulated operative part of a machine tool. The communication between the agents is achieved thanks to an Ethernet network and CORBA protocol. The experiments (with and without cooperation between agents for accommodating) give encouraging results for implementing the proposed control framework to operational machines. Also, the cooperation between the agents of control and monitoring framework contributes to the improvement of reactivity by adapting cutting parameters to the machine and process states and to increase productivity

Fabrication and characterization of nanostructured fluorine doped tin oxide thin film for dssc by hydrothermal method

Nanostructured Fluorine Doped Tin Oxide (FTO) thin film has been successfully synthesized on top of bare FTO layer substrates using hydrothermal method. The performance of FTO thin film including conductivity and transparency depend on the surface morphology and the properties of the material. Hydrothermal method has proven to be a very good method for the fabrication of novel metal oxides. Thus, a new nanostructured FTO thin film like nanorice has been fabricated using one step hydrothermal method. FTO nanorice thin films were obtained from the reaction of tin (iv) chloride (SnCl4), ammonium fluoride (NH4F), acetone, deionized water and hydrochloric acid (HCl). The compound was prepared in an autoclave at 150°C hydrothermal temperature for different reaction times of 5 hours, 10 hours, 15 hours, and 20 hours. FESEM studies on the surface morphologies of all the samples showed that nanorice structure had formed to fully cover the bare FTO substrate. Then, to further the optimization of FTO nanorice thin film, this research focused on studying the effect of hydrothermal temperature on FTO nanorice thin films. The experiments were conducted at 130°C, 140°C, 150°C, 160°C, and 170°C of hydrothermal temperature in constant reaction time of 10 hours. Basically, there were six properties studied; surface morphology, structural, element composition, thickness measurement, electrical and optical properties. At the end of this research, homogeneous FTO thin film has been successfully prepared. By controlling the reaction time and hydrothermal temperature, a transparent FTO film with beyond 85% percentage of transmittance was developed. The FTO thin film produced at 10 hour reaction time and 150°C of hydrothermal temperature time gave the low sheet resistance of 0.012 Ohm/sq with high transparency. The DSSC fabricated using the optimized FTO film gave higher efficiency of 2.77% compared to commercial FTO of 1.93%