Electromechanical Products Research Articles

Efficient Sparse Representation Response Surface Modelling and Simulation Method for Complex Products

With the composition and control of modern electromechanical products more and more complex, the time of solving simulation model is longer and longer. The response surface simulation optimization method is an effective method to reduce the simulation time, however, the number of design sampling points of response surface approximation is still large. In this paper, we propose a sparse representation response surface model to accurately reconstruct the source model with small amount sampling points. By means of the sparse representation of the source model on a specific basis, most of the coefficients are zero which can be solved by the equations constructed from small number of sampling. Sparse representation response surface models include sparse response surface and quasi-sparse response surface which are respectively applied to the case where the number of sampling points is greater than and less than the degree of sparse. Sparse response surface runs quicker and quasi-sparse response surface has higher accuracy. Two test functions and one engineering practice problem are employed to compare the performance between sparse representation response surface model and other common response surface models. The results show that the sparse representation response surface model has better performance in approximate accuracy and simulation efficiency.

AHP, Gray Correlation, and TOPSIS Combined Approach to Green Performance Evaluation of Design Alternatives

The green design of electromechanical products is a pivotal link to manufacturing industry. The question on how to design green products must be answered by excellent designers using both advanced design methods and effective assessment techniques of design alternatives. Making an objective and precise assessment of green designs is of increasing importance to ensure sustainable development. This work proposes a framework based on the combination of analytical hierarchy process (AHP), gray correlation (GC), and technique for order performance by similarity to ideal solution (TOPSIS) to evaluate the performance of design alternatives. AHP is used to determine the weights of performance indices and a nonlinear programming model with constraints is proposed to obtain the integrated closeness index based on the similarity closeness index from GC and distance closeness index from TOPSIS. A case study, i.e., three kinds of refrigerators, is illustrated to verify the proposed method. By comparing with existing methods, i.e., AHP-TOPSIS and AHP-GC, the effectiveness of the proposed method has been confirmed. In addition, sensitivity analysis is also provided in order to assess the robustness of the proposed method. Also, the following implication can be obtained from our results: 1) chloro–fluoro–carbons (mg/ $\text{m}^{3}$ ) (C1), production noise (dB) (C6), and environmental cost (C16) have a large impact on refrigerator’s green design since these factors carry relatively larger weights. Results of the sensitivity analysis from different cases demonstrate that the best alternative may change when different weights are assigned to the evaluation criteria. This finding means the importance of establishing a qualified group of experts/designers in design evaluation and 2) the selection of design alternatives to produce a green product is critical to product development. The main contribution of this paper is the definition and development of an effective evaluation framework to guide managers to assess product design alternatives. The results show that it overcomes the one-sidedness of AHP-TOPSIS and AHP-GC, and makes the evaluation results more objective and realistic. It provides an accurate, effective, and systematic decision support tool for green performance evaluation of product design alternatives.

Evaluation of pull production control strategies under uncertainty: An integrated fuzzy AHP-TOPSIS approach

Purpose: Just-In-Time (JIT) production has continuously been considered by industrial practitioners and researchers as a leading strategy for the yet popular Lean production. Pull Production Control Policies (PPCPs) are the major enablers of JIT that locally control the level of inventory by authorizing the production in each station. Aiming to improve the PPCPs, three authorization mechanisms: Kanban, constant-work-in-process (ConWIP), and a hybrid system, are evaluated by considering uncertainty.Design/methodology/approach: Multi-Criteria Decision Making (MCDM) methods are successful in evaluating alternatives with respect to several objectives. The proposed approach of this study applies the fuzzy set theory together with an integrated Analytical Hierarchy Process (AHP) and a Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method.Findings: The study finds that hybrid Kanban-ConWIP pull production control policies have a better performance in controlling the studied multi-layer multi-stage manufacturing and assembly system.Practical implications: To examine the approach a real case from automobile electro mechanical part production industry is studied. The production system consists of multiple levels of manufacturing, feeding a multi-stage assembly line with stochastic processing times to satisfy the changing demand.Originality/value: This study proposes the integrated Kanban-ConWIP hybrid pull control policies and implements several alternatives on a multi-stage and multi-layer manufacturing and assembly production system. An integrated Fuzzy AHP TOPSIS method is developed to evaluate the alternatives with respect to several JIT criteria.

A new low-cost installation scheme of PATs for pico-hydropower to recover energy in residential areas

Abstract A limiting factor in the use of hydropower plants in water supply networks consists in the cost of the electromechanical production device and the equipment necessary for the plant regulation. Pumps as Turbines (PATs) are electromechanical devices that have already been used in many mini and micro hydropower plants. Due to their low cost and reliability, PATs are an optimal solution for pico-hydropower plants, whose regulation has been widely analysed in literature, for power installations of only a few kW. A new power plant for small residential areas is presented herein. The new low-cost plant is provided with two PATs, that can work as single, series or parallel (SSP) turbines, and three on/off valves, whose synchronous operations regulate the flows and the head loss. The proposed design method is based on the maximization of the effectiveness of the system. Experimental data on a PAT are used to simulate the plant in several hydraulic conditions, with the application of the turbomachinery affinity law. The simple plant operations and the resulting interactions with the network confirm the viability of the proposed scheme. An economic assessment shows the feasibility of the new plant in different hydraulic situations.

Developing a Curriculum for Sino-Australia Cooperative Mechanical Engineering Program

Guided by the purpose of fostering international high-quality engineering personnel, based on the problems found in a curriculum setup of Sino-Australian Mechanical Engineering collaborative teaching program. This study is focused on developing the curriculum setup that takes modern electro-mechanical product and system design as the principle, and develops students' fundamental, core and comprehensive employability as the centre, as well as achieves Sino-foreign mechanical engineering curriculum that includes target and contents, theoretical knowledge and practical projects, traditional classroom and online delivery, via research and practice from four aspects including course setup, practical component, teaching mode and assessment scheme, in order to provide theoretical and practical reference for a better Sino-foreign collaborative teaching model and reform of relevant teaching scheme. This paper discusses about the design and implementation of a Curriculum for Mechanical Engineering for the joint program. This Curriculum aims to educate the students, a multidisciplinary knowledge in the domain of Engineering, technology as well as management. The implementation of this curriculum at Wuhan University of Science and Technology has showed a large improvement of student skills that permits it to become a national curriculum. https://doi.org/10.26803/ijlter.17.2.4

Reliability measure model for electromechanical products under multiple types of uncertainties

Reliability measure is a fundamental problem in reliability engineering due to the electromechanical products should be with high performance speed and position control with the flexibility to adapt to the rapidly changing needs. The coexistence of random uncertainty, fuzzy uncertainty and incomplete trust uncertainty is common. However, a reliability measure model for this scenario has not been fully studied. Hence, the fuzzy reliability measure (FRM) model is proposed, which enables the reliability of any combination of random and fuzzy variables to be solved. In order to further consider the incomplete trust uncertainty in the reliability measure process, the improved fuzzy reliability measure (IFRM) model is presented based on the FRM model. The hyper entropy of the cloud model is used to consider the incomplete trust uncertainty, providing improved processing. Besides, the concept of credibility is introduced to indicate the degree of trust in the reliability measure results. The reliability-credibility curve is viewed as the reliability measure result of the IFRM model. The reliability and credibility of the electromechanical products under multiple types of uncertainties can be obtained. Besides, the reliability-credibility curve showed the probability of reliability being greater than a certain value and read one certain credibility and its corresponding reliability interval. The calculated results were compared with those obtained from the other methods, which demonstrated the accuracy and wider applicability of the IFRM model. The IFRM model establishes the relationship between reliability and credibility and used as a theoretical basis for either reliability studies or the development and improvement of the reliability of electromechanical products.

Case Study on Failure Analysis of Electrostatic Discharge Damage of Semiconductor Devices

The semiconductor device has been widely used in electromechanical products. Electrostatic discharge damage is an important reason for the failure of semiconductor devices, so the electrostatic discharge damage failure analysis plays an important role in determining the reasons for the failure of semiconductor devices and making rectification and improvement measures. Through collecting and analyzing cases of electrostatic discharge failure analysis, the main technology of electrostatic discharge failure analysis and the methods of analyzing electrostatic discharge damage are summarized. The suggestion of electrostatic discharge damage failure analysis is also given.

Research on Quality Evaluation Model with the Application of Mechanical and Electrical Products Based on IAHP

Aiming at the multi-level and multi-index problem of the quality evaluation index of mechatronic products, a comprehensive analysis method based on the improved AHP model is put forward. The analytic hierarchy process (AHP) determines the relative importance of each factor by pairwise comparison, and then synthesizes the decision. In the actual operation process, the analytic hierarchy process uses nine scale method to determine the judgment matrix. The judgment process is complex that often cannot get consistent results and reduce reliability. In this paper, the improved analytic hierarchy process (IAHP) is used to quantify the influence of parameters on the quality evaluation index. The judgment matrix is determined by the three scale method. The operation is simpler and easier to keep the consistency of the matrix. The method should be applied to modeling and calculating the factors affecting the quality of electromechanical products in an enterprise, and the validity of the method is verified.

Influence of Processing Location Hole on a Radial Magnetic Bearing Performance

As an electromechanical product, the performance of a magnetic bearing (MB) is determined not only by the original design, but also by the process and the assembly process. The location hole is a necessary part of the machining and assembly. In this paper, the influence of the location hole on the performance of the magnetic bearing is analyzed by the combination of equivalent magnetic circuit method and finite element method. The main performance with and without location hole are compared in detail, including magnetic field distribution, bearing capacity, current stiffness and displacement stiffness. Through the analysis, the sufficient margin for installation process should be fully guaranteed at design stage.

Geometrical specifications accuracy influence on the quality of electromechanical devices

To improve the quality of electromechanical products is possible due to the geometrical specifications optimization of values and tolerances. Electromechanical products longevity designates the rolling-contact bearings of the armature shaft. Longevity of the rolling-contact bearings is less than designed one, since assembly and fitting alter gaps, sizes and geometric tolerances for the working parts of the basic rolling bearing details. Geometrical models of the rolling-contact bearing details for the armature shaft and the end shield are developed on the basis of an electric locomotive traction motor in the present work. The basic elements of the details conjugating with the adjacent details and materializing the generalized and auxiliary coordinate systems are determined. Function, informativeness and the number of geometrical specifications for the elements location are specified. The recommendations on amending the design documentation due to geometrical models to improve the accuracy and the quality of the products are developed: the replacement of the common axis of the shaft’s technological datums by the common axis of the basic design datums; coaxiality tolerances for these design datums with respect to their common axis; the modifiers for these auxiliary datums and these datums location tolerances according to the principles of datums uniformity, inversion and the shortest dimension chains. The investigation demonstrated that the problem of enhancing the durability, longevity, and efficiency coefficient for electromechanical products can be solved with the systematic normalizations of geometrical specifications accuracy on the basis of the coordinate systems introduced in the standards on geometrical product specifications (GPS).

Process optimization and performance evaluation on laser beam welding of austenitic/martensitic dissimilar materials

Laser beam welding of austenitic/martensitic dissimilar combination is used in a precision electromechanical product for function design. In order to achieve the better mechanical performance and physical performance of welding joints, process optimization was first carried out according to the Box-Behnken design method, and mathematical response models of weld depth and peak temperature value at special point were developed by multivariate quadratic/linear regression analysis. An optimal group of welding process parameters is obtained. Then, mechanical performance was evaluated by micro-structure analysis, non-destructive test, and uniaxial tensile test, and the influence of cooling style after laser beam welding process was discussed on hardness distribution and fracture force. It is shown that a rapid cooling style can avoid the crack occurrence at the heat-affected zone of austenitic stainless steel and enhance fracture force of weld joint. However, the hardness distribution is not even, and it has the highest value at the heat-affected zone of martensitic stainless steel and the lowest value at the heat-affected zone of austenitic stainless steel. However, the welding joint has a better mechanical performance under the condition of low temperature.

Overview of Key Quality Characteristics Identification of Complex Electromechanical Products

Overview of Key Quality Characteristics Identification of Complex Electromechanical Products

机电产品的绿色制造工艺研究

随着可持续发展战略的提出，人类越来越意识到社会发展与环境友好之间相互协调的重要性，机电产品的可持续发展研究具有重要意义。对机电产品绿色制造的研究主要集中在：机电产品制造过程的能耗模型的研究、机电产品绿色制造工艺的选择及机电产品绿色制造工艺要素的研究。 With the introduction of sustainable development strategy, the humans are more and more aware of the importance of coordination between social development and environmental friendly. The research of sustainable development of mechanical and electrical products is of great significance. This paper studies the green manufacturing of electromechanical products from the energy consumption model of electromechanical products manufacturing process, the choice of green manufacturing technology of electromechanical products and the green manufacturing process elements of electromechanical products.

A Mapping Network Model Integrating Service to Warrant Function Availability of Complex Electro-mechanical Products

In recent years, in order to obtain value increment of enterprises, product service system (PSS) that integrates products and services is attracting more and more attentions in life cycle. Meanwhile, in the product usage phase, the maintenance actions undertaken in-house by customers haven’t fully warranted products’ availability for increasingly complex electro-mechanical products. So, for the purpose of warranting function availability (i.e. the availability of a function for operation) and improving equipment's operation performance by integrating services, it is necessary to allow for the complex interactive relationships among functions, structures and services to implement service's integration. According to the research on PSS, to further discuss the integrating and mapping process from the standpoint of network modeling, the mapping network model integrating service is proposed. Concretely, this model includes function layer, structure layer, service layer and their mapping network relationships. In function layer, a multi-view function decomposition model with hierarchical design structure matrix (HDSM) is introduced to present function nodes and their inherent correlations, comprehensively. In structure layer, the structure nodes are mapped from normalized mapping process and their interdependence relationships are also quantified to fulfill the integration of structure network. In service layer, the concept of service activity chain (SAC) is presented to fulfill the mapping from structure nodes to service nodes with the advantage of failure tree analysis (FTA). What's more, the provider nodes are also integrated in it. Thereby, once the network is built, the functions of equipment could be warranted effectively by corresponding structures and service execution processes. In the end, a simple case of honing head subassembly of CNC honing machine 2MK2263×200 is studied to verify the feasibility of the proposed method.

Measurement and Assembly of Microminiature Parts Based on Micro Machine Vision

With the development of modern high precision processing technology, precise microminiature electromechanical products have been widely used. Most of the precise microminiature electromechanical products are assembled from microminiature parts.Due to dimensions of the microminiature parts involved are in micro-and nanoscale, which cannot be reached by ordinary cameras, it cannot effectively capture the image of those parts to be assembled, thus affects the assembly. A microscopic vision measurement system of stereo microscope that combined with high resolution CCD camera was developed based on micro machine vision, which uses the MATLAB software to deal with the collected images of microminiature parts such as image smoothing, image sharpening, image segmentation and edge extraction, etc. to study the structures, identification, location and assembly process of microminiature parts. The results show that the visual system we used has accomplished the automatic measurement and precise assembly of miniature parts excellently.

Optimization for Disassemble Sequence Planning of Electromechanical Products during Recycling Process Based on Genetic Algorithms

Disassemble and re-manufacturing is an important way to save energy. Sequence planning is the core issue of disassemble. In this study, disassemble model has been established based on the analysis of disassemble route planning and disassemble sequence. The disassemble sequence optimization based on genetic algorithms has been carried out. In the gear pump disassemble sequence, for example, an illustrative example, proposed in this study to verify the disassemble sequence planning based on electromechanical product recovery process optimization genetic.

Modelling infant failure rate of electromechanical products with multilayered quality variations from manufacturing process

The optimisation of product infant failure rate is the most important and difficult task for continuous improvement in manufacturing; how to model the infant failure rate promptly and accurately of the complex electromechanical product in manufacturing is always a dilemma for manufacturers. Traditional methods of reliability analysis for the produced product usually rely on limited test data or field failures, the valuable information of quality variations from the manufacturing process has not been fully utilised. In this paper, a multilayered model structured by ‘part-level, component-level, system-level’ is presented to model the reliability in the form of infant failure rate by quantifying holistic quality variations from manufacturing process for electromechanical products. The mechanism through which the multilayered quality variations affect the infant failure rate is modelled analytically with a positive correlation structure. Furthermore, an integrated failure rate index is derived to model the reliability of electromechanical product in manufacturing by synthetically incorporating overall quality variations with Weibull distribution. A case study on a control board suffering from infant failures in batch production is performed. Results show that the proposed approach could be effective in assessing the infant failure rate and in diagnosing the effectiveness of quality control in manufacturing.

RFID-based integrated method for electromechanical products disassembly decision-making

Proper recovery of electromechanical products can prevent pollution, improve materials recycling rate and make economic benefits as well. However, a major obstacle is that the product lifecycle information essential for the recovery decision-making is difficult to be collected. This article shows how radio frequency identification (RFID) can be utilised to record and trace the lifecycle information, hence optimising disassembly process and improving recovery efficiency. The key factors of the integrated method are demonstrated: (1) an assembly–disassembly model is constructed purposefully due to characteristics of RFID; (2) a flexible encoding and storage approach using XML format is proposed uniquely for a universal usage of the limited memory space in RFID tags; and (3) a detailed iteration process for the automatic generation of a near-optimum disassembly sequence is illustrated. In addition, a set of related application programmes are developed, and the whole integrated method is verified by a case study. This integrated method is highly extensible, and it can be applied to various types of electromechanical products.

Accuracy and Precision Analysis of the Graph Complexity Connectivity Method

For a given electro-mechanical product, represented using assembly models and function structures, the assembly time (AT) and market value (MV) are influenced by complexity of the product. Given the AT and MV of a set of known products, complexity values can be used to predicted AT and MV for a set of unknown products using an Artificial Neural Network. This paper presents a precision analysis of four prediction models that are a combination of the aforementioned design representations and AT and MV. A sensitivity analysis of the complexity metrics was done using Multiple Linear Regression, and a set of significant metrics was identified. Lastly, a comparison of accuracy and precision for the four prediction models obtained using this set of sensitivity analysis is presented.

Wpływ koniunktury gospodarczej – kryzysu i depresji na eksport polski do krajów EWG w latach 70. XX wieku

In Polish exports to EEC countries in the 1970s there were no industrial products, which, due to its high competitiveness, would be resistant to the impact of cyclical fluctuations in import demand in Western Europe. In the case of Poland, ships, railway rolling stock, rolling bearings, and woodworking machines within the electro-mechanical industry, pharmaceuticals within the chemical industry and knitting products within the light industry were the most likely to be included among such strong export items. The emphasis on improving the quality of these goods and giving them a truly pro-export production character was in future to result in higher economic resistance of total Polish exports. This was particularly important in the case of the electro-mechanical industry products, the share of which in the total Polish exports showed a steady increasing trend, and the export of which, as well as the steel industry, was included among commodity groups that were the most sensitive to economic trends in Polish exports to EEC countries.