Robot evaluation and selection Part A: an integrated review and annotated taxonomy

Robot selection for a given industrial application is a challenging and complicated procedure. The production system, comprising a variety of applications with different specifications and demands, perceives the necessity for rapid and effective decisions. In addition, the procedure of robot selection is encumbered by the number of alternative options and the nature of their characteristics. The plethora of methodologies which have been introduced, during the last four decades, for the solution of robot selection problem, raises the need for an extensive research which could incorporate all the corresponding articles of the literature. In the current article, an extensive, aggregate, and detailed review for robot selection problem (RSP) is presented, including a wide variety of models, ranging from the first attempts which have been developed in order to approach the issue to the most contemporary and flexible decision methodologies. In advance, these models are classified considering the pattern of RSPs and analyzed according to robots’ attributes as well as to decision parameters. The advantages and disadvantages of each method are also mentioned, considering the flexibility and the other utility parameters. The significance of this work initially lies in the fact that it presents the aforementioned information in a compact and organized way and highlights the main distinctivenesses of each method/category. Using comprehensive tables and diagrams, the particular work aims to be an informative companion for future researches in the field of robot selection.     

Continuous improvement - Nissan's supplier struggle with continuous improvement - THE NISSAN SUPPLY CHAIN IS MORE FRAGILE THAN ITS ENVIABLE REPUTATION SUGGESTS

Nissan Motor Manufacturing UK must be among the best in the world. But a three-year study by a Nissan insider, based on surveys and interviews among Nissan's 265 suppliers, reveals that the Nissan supply base is full of companies who underestimate both their competitors and their employees. They are over-reliant on continuous improvement (CI) tools and methodologies that they do not fully understand. Moreover, they have little idea what CI means either in practical terms or in terms of management commitment. Eight CI myths derived from the study are: the idea that employee attitudes are the biggest barrier to CI success; lean suppliers must make large investment in CI tools and methodologies; CI tools will solve all of a company's problems; consultants know which tools are right for a business; CI is all about becoming leaner, and this means downsizing and reducing the headcount; CI is only about cost reduction; CI does not deliver quick improvements; and that CI is going to cost the company. The article sheds light on these myths     

An empirical study to evaluate machine tool production readiness and performance

Purchasing the correct machine tool can have strategic implications for manufacturers, because incorrect selection will eventually lead to quality and productivity losses. Prior research has concentrated on developing an analytical decision support system to select and compare machine tools based on machine functionality—not capability. Machine tool selection decision analyses concentrate on machine specifications and characteristics, which disregard the actual machine accuracy and dynamic performance. In this paper, the need to include machine accuracy and performance in terms of cycle time, tool wear, and surface finish is described with a case study of manufacturing a typical aerospace component using three different production methodologies on three computer numeric controller milling machines. Even though the three selected machine tools have similar technical specifications, which are adequate to manufacture the sample aerospace part, the machine accuracy and dynamic machining performance of the machines is significantly different. We conclude that it is necessary to include machine tool performance and production readiness attributes and not solely rely on the specifications when considering machine tool selection and purchasing.     

Analysis of modularity implementation methods from an assembly and variety viewpoints

The advent of product modularity has enabled the manufacturing firms to develop substantial product variety at lower costs and shorter lead times. Several modular design methodologies exist in the literature, but each method was developed to optimize a certain criterion. It is also not clear which method would provide the best results under a specific case, as most of these methods have not yet been compared quantitatively. This paper reviews and compares three well-known modularizing methodologies in order to determine the method generating the best modularized design. Our hypothesis for comparison is that the method offering highest ease of assembly, and accommodating design for variety to meet future customer needs, is the best. An electronic toothbrush and a bicycle are used to compare the three methodologies: (1) function heuristic method, (2) behavioral-driven function–environment–structure (B-FES) modeling framework, and (3) decomposition approach.     

An integrated analytic network process with mixed-integer non-linear programming to supplier selection and order allocation

As the global business environment changed, much more commercial and technological competitions evolved in this environment. Consequently, more attention is devoted to the business partners including suppliers. In this paper, supplier selection with order allocation problem is addressed for strategic items with respect to the materials’ characteristics as well as what has been mostly considered in the literature, suppliers’ characteristics. The proposed model comprises an analytic network process (ANP) sub-model to qualify suppliers and filter-suitable candidates among the available ones. Additionally, the ANP sub-model is applied to evaluate suppliers regarding their qualitative attributes which cannot be modeled with mathematical tools properly. Moreover, a mixed-integer non-linear sub-model is presented to simultaneously allocate order quantities to the chosen suppliers. The model is customized to the strategic items by introducing supplier switching cost which is a notable cost component for products. Finally, experimental results and sensitivity analyses are presented to validate the proposed model.     

Assembly process planning and its future in collaborative manufacturing: a review

A good assembly process plan can increase the efficiency and quality, and decrease the cost and time of the whole product manufacturing process, which is important as product and production demand changes rapidly in today’s market. Several approaches using different techniques and methodologies have been developed and reported in the literature for assembly process planning. Automated assembly process planning (AAPP) has been the main focus of the research efforts over the years, with most work concentrated on attempting to automate or to semi-automate the key sequencing process. However, some of these efforts have not been successful in general, and many assembly process plans are still based on traditional methods. The purpose of this paper is to review and outline the methodologies and tools in assembly process planning developed during the past ten years, such as the application of meta-heuristics methods to find the optimal/near optimal assembly plans and assembly line balancing, the evaluation methods for design for assembly (DFA), and collaborative assembly process planning systems. Based on this review the future trends in this area are also identified and discussed.     

Selection of optimal machining parameters for hexapod machine tool

Parallel kinematic machine tools (PKM) have the advantages of higher stiffness, higher payload capacity and lower inertia. Still their penetration into the machine tool industry is very less. One of the difficulties in using PKMs such as hexapod machine tools is that the stiffness continuously varies with configuration change at every instant. This makes location of work piece and selection of machining parameters difficult and complicated. A methodology is presented in this article to select optimal machining parameters for hexapod machine tools. Particle swarm optimization is used as a tool in the optimization process. A profile-milling example is also presented to demonstrate the selection of machining parameters.     

Selection of optimal set of cutting tools for machining of polygonal pockets with islands

Selection of the optimal set of cutting tools is one of the most important steps in process planning for 2.5-D pocket machining. Conventional CAM software requires considerable input from the user in terms of selection of tool sizes and machining strategy. This trial-and-error procedure to determine the optimal process sequence tends to generate conservative and suboptimal results. This paper presents a methodology for optimal selection of a sequence of tools to minimize the total time required to end mill a non-convex polygonal pocket with or without islands using the staircase milling strategy. The algorithm decomposes the pocket geometry into convex regions and mills each region independently by selecting a sequence of tools based on the accessibility of various tools to the region. Strategies have been developed for machining the main pass and the subsequent leftover areas in order to obtain the final pocket geometry. Subsequently, the machining times for each decomposed area are aggregated while accounting for the need to use multiple passes, non-cutting time, and the tool change time. A dynamic programming approach is used to determine the optimal set of tools which minimizes the total processing time. The effect of varying the non-cutting speed and tool change time on the tool path length and number of tool selection is studied.     

An integrated design methodology based on the use of group AHP-DEA approach for measuring lean tools efficiency with undesirable output

The selection of lean tools is one of the crucial factors for decision makers and practitioners in a competitive environment. A few efforts have been made based on problem selection. Conversely, numerical studies have been done on analytical hierarchy process (AHP)–data envelopment analysis (DEA) as well as DEA-undesirable variables separately. Thus, there is a shortage of lean practitioners as well as the methods involved. The present research aims at integrating AHP and DEA with desirable and undesirable factors to evaluate the lean tools and techniques and to rank the aspect of efficacy. We suggest a logical procedure to measure the efficacy of lean tools on leanness and to prioritize them as decision makers. In this extensive research, we apply the integrated multicriteria decision-making approach, including the hybrid groups AHP and DEA models with desirable and undesirable variables, to assess the relative efficiency of lean manufacturing tools and techniques. Case studies are used to demonstrate the lean implementation in companies while being validated by a panel of experts. The integration of these approaches has created synergy and shown to be even more powerful. Thus, the proposed integrated AHP-DEA model can evaluate and rank different alternatives while considering desirable and undesirable variables in the production processes.     

Input variable selection for model-based production control and optimisation

For model-based production control and optimisation, it is crucial to properly identify those input variables that have the strongest influence on production performance. This way, production operators can focus only on the relevant variables, and production control problems can be reduced. In order to identify previously unknown relationships among the production variables, hidden knowledge in historical production data needs to be explored. In the article, two decisive steps are considered. First, an input variable selection methodology, typically applied for selecting model regressors, is applied. Next, the appropriateness of the selected inputs and their manipulative strength is validated by an operating-space-based controllability analysis. To use the most appropriate input variable selection approach, different input selection methodologies are compared with synthetic data sets. Moreover, a case study of Tennessee Eastman process is applied to demonstrate a complete input variable selection procedure for model-based production control and optimisation.     

Modelling approach for the simulation-based preliminary design of power transmissions

The promises of Model-Based Design have led to the development of numerous methodologies and software tools, especially for the specific or detailed design stages, from controller design to finite element analysis. However, the Model-Based Design of actuation systems lacks methodologies and expressive simulation models that are suited to preliminary design, where key technical decisions are taken considering various design alternatives and few available design details. In order to fill this gap, the present paper illustrates how scaling laws and acausal modelling can be used as a design tool, exploiting inverse simulation capabilities to evaluate technological alternatives quantitatively from limited design detail information. The application of the modelling approach is shown for two major components of mechanical transmission systems: roller bearings and ball and roller screws. The scaling laws presented are validated with manufacturers’ data. To conclude, the suitability of the proposed methodology is illustrated with the preliminary sizing of an electromechanical actuator for an aircraft primary flight control surface (aileron).     

联邦企业体系结构框架研究

为解决企业工程活动中关于企业体系结构框架和方法学的评价、建立、选择和使用等具体问题,阐述了系统化的研究步骤和方法.首先介绍了联邦企业体系结构框架及其方法学、使用指南、参考模型.然后利用ISO标准通用企业参考体系结构和方法学,研究联邦企业体系结构框架,并探讨二者之间的匹配关系,研究及评价的具体参照物包括通用企业参考体系结构和方法学元模型中的主要组件,主要内容包括:生命周期、模型框架、建模语言、方法学、参考模型、通用企业模型概念、企业模型工具和企业模块等.最后,总结了联邦企业体系结构框架的优点和不足之处.     

Cellular and molecular biology of ensheathing cells

Ensheathing cells are the glial cells that envelop olfactory axons as they course from the olfactory epithelium to the bulb. They are derived from the olfactory placode and differ from the typical glia in terms of sharing the phenotypes of both astrocytes and Schwann cells. The aims of this study are to review (1) cellular characterisation of ensheathing cells in vivo and in vitro, (2) molecular insight into their growth promoting properties, and (3) their role in olfactory development and potential function as a therapeutic agent for nerve repair. Much of the characterisation of ensheathing cell property has developed from immunohistochemical studies that have been supplemented with new molecular methodologies in recent years. Many pieces of evidence clearly indicate that ensheathing cells actively produce growth-promoting molecules, which act in a paracrine and, in some cases, autocrine manner. However, a review of the available literature also suggests that there is a great deal that remains to be elucidated regarding the cell biology of ensheathing cells, for example, their rate of formation and turnover. In addition, the apparent antigenic heterogeneity as revealed by numerous in vitro studies warrants further analysis, particularly in view of the fact that in recent years these cells have been touted as a possible agent for central nerve repair. New molecular methodologies such as the microarray techniques will prove to be crucial for defining the unique characteristics of ensheathing cells.     

A tool-regulation and balancing system for turning centres

The tool-balancing system described in this paper regulates the selected tools for the machining of a certain component on a turning centre and optimises the tool-changing strategy on a machining-cost basis. The regulation of the tools represents a correlation between the total number of tools selected and the available tool positions on the machine tool. When there are free tool positions on the turret, duplicates of the high-wear tools can be used in order to reduce the number of interruptions for tool changing. When the number of tools is greater than the number of turret positions, some tools are automatically replaced by others which are already being used for different operations and which offer geometrical suitability and compatible performance. Further, the tool-changing strategy is optimised by modifying the optimum tool life and/or the cutting data. The system has been successfully tested for a variety of applications and it has resulted in increased productivity and machinetool utilisation.     

高速铣削铝合金刀具选型及模糊综合评判

铝合金的高速铣削是高速切削技术的重要应用领域之一,高速铣削刀具的选型是企业在生产实践中面临的一个重要问题。从研究切削力入手,对刀具材料、刀具前角、刀具品牌三个因数,进行试验优化研究。运用模糊综合评判的方法对高速铣削刀具的选型进行评价。     

Web-based CBR (case-based reasoning) as a tool with the application to tooling selection

Over the past few years, manufacturing companies have had to deal with an increasing demand for feature-rich products at low costs. The pressures exerted on their existing manufacturing processes have lead manufacturers to investigate internet-based solutions, in order to cope with growing competition. The decentralisation phenomenon also came up as a reason to implement networked-application, which has been the starting point for internet/intranet–based systems. Today, the availability of powerful and low cost 3D tools, database backend systems, along with web-based technologies, provides interesting opportunities to the manufacturing community, with solutions directly implementable at the core of their businesses and organisations. In this paper a web-based engineering approach is presented to developing a design support system using case-based reasoning (CBR) technology for helping in the decision-making process when choosing cutting tools. The system aims to provide on-line intelligent support for determining the most suitable configuration for turning operations, based on initial parameters and requirements for the cutting operation. The system also features a user-driven 3D turning simulator which allows testing the chosen insert for several turning operations. The system aims to be a useful e-manufacturing tool being able to quickly and responsively provide tooling data in a highly interactive way.     

面向加工特征的刀具和切削参数计算机辅助选择系统

切削刀具制造商面临围绕大量工件材料和加工特征为客户提供合理刀具和切削参数的现状,切削工艺规划的核心步骤也是刀具和切削参数的确定。确定刀具和切削参数一般多从零件材料角度出发,可能导致工件与刀具不匹配。文中提出面向加工特征的刀具和切削参数计算机辅助选择系统的开发。系统包括车削特征、铣削特征、钻削和镗削加工特征,系统利用特征图形作为用户交互式接口,采用关系数据库结合数据驱动和规则推理逻辑来选择刀具和切削参数,利用数学模型计算过程参数包括单工步加工工时、切削功率、最大粗糙度等,并辅助制定工序。以车刀和车削参数选择为例,介绍该系统的实现方法。该系统可以辅助设计师及工艺人员选择合理的刀具和切削参数。     

Scheduling approaches for the batch process industries

The elements of scheduling, a decision methodology which is appropriate whenever competing activities must be assigned resources over time so as to achieve desired performance objectives, are outlined. The key difficulty of such problems, namely their characteristically high combinatorial complexity, is reviewed and the range of approximate as well as exact methodologies which have been advanced for their solution are highlighted. Batch process scheduling problems are shown to be highly structured and resource constrained and thus not readily amenable to the full range of generic solution approaches. Model-based optimization approaches, validation using detailed simulation models, are proposed as the most appropriate decision support technologies for this domain. The optimization models use simplified product recipes, time discretization constructions, linear material and other resource balance constraints, and application specific economic objective functions. The core solution methodology consists of mixed integer and linear programming methods, specialized to exploit model structure. The role of combined continuous-discrete simulation models is to allow adjustment of the scheduling information obtained from deterministic, linear models to account for the detailed recipes, fine grained representation of time, nonlinear state dependent effects, and stochastic operational and order information, which are characteristic of plant operations. It is proposed that the model-based optimization and simulation approaches are inherently complementary and offer the best prospects for the routine creation and validation of robust and economical operational schedules for the batch environment. Work in progress to integrate these methodologies is noted and some open issues discussed.     

微小孔钻削刀具制造技术研究进展综述

随着航空航天、医药、汽车及电子工业的迅速发展,精密设备及微结构的制造需求逐年增加,微小孔(d≤1mm)作为微结构中的常见难加工特征,其制造技术是限制相关领域装备发展的关键所在,因此,微小孔制造一直是机械加工行业的研究热点和难点,诸多学者从多种维度进行了相关研究,形成了丰硕的研究成果。由于微小孔钻削技术现阶段仍然是微小孔制造的核心工艺,而刀具性能则是保证微小孔钻削的核心要素,因此总结了近年来微钻刀具制造领域的重要技术进展,并从微钻刀具的材料选择、几何角度设计、制造工艺方法等角度展开叙述,介绍了最新的微钻刀具材料研究进展、解释了微钻刀具几何角度的设计方法,总结对比了国内外最新的微钻刀具制造技术,包括磨削、电火花磨削、高频激光加工技术等。由于PCD微钻具有优异的切削性能和极大的技术潜力,还重点介绍了PCD微钻制造技术及最新研究成果,并针对不同材料、工况下的微小孔钻削加工工艺参数进行了总结。     

Design and Manufacturing Strategies for Fused Deposition Modelling in Additive Manufacturing:A Review

Although several research works in the literature have focused on studying the capabilities of additive manufacturing(AM) systems, few works have addressed the development of Design for Additive Manufacturing(DfAM) knowledge,tools, rules, and methodologies, which has limited the penetration and impact of AM in industry. In this paper a comprehensive review of design and manufacturing strategies for Fused Deposition Modelling(FDM) is presented.Consequently, several DfAM strategies are proposed and analysed based on existing research works and the operation principles, materials, capabilities and limitations of the FDM process. These strategies have been divided into four main groups: geometry, quality, materials and sustainability. The implementation and practicality of the proposed DfAM is illustrated by three case studies. The new proposed DfAM strategies are intended to assist designers and manufacturers when making decisions to satisfy functional needs, while ensuring manufacturability in FDM systems.Moreover, many of these strategies can be applied or extended to other AM processes besides FDM.