A system for the design and manufacture of feature-based parts through the Internet

The Internet has enabled the development of applications for supporting the design and manufacturing of industrial parts and products. Some actions have been performed by some research groups in different parts of the world aiming at conceiving product modeling systems based on the technology of features to allow information sharing, both for the activities related to product development and for manufacturing. This paper describes the implementation of the WebMachining system () developed in a context of e-Mfg and concurrent engineering, aimed at integrating CAD/CAPP/CAM for the remote manufacturing of feature-based cylindrical parts with symmetrical and asymmetrical features through the Internet, using an approach based on multi-agent systems. The information referring to the features is manipulated through a relational database management system. The graphic user interface (GUI) is implemented in Java and HTML. In this GUI, the user inputs the information on the design features that compose the part. Then these data are sent to the server. Since the part is cylindrical, the user models the part in two dimensions, and it can be visualized as three-dimensional through VRML. A database was implemented that stores the information on the product modeled by features, containing information associated with the form features, material features, tolerance features and technological features. These combined pieces of information allow the mapping of design features into machining features, which is fundamental for process planning. The database information is described in this article through the IDEF1X information model.     

Process chains for the manufacturing of molded interconnect devices

Moulded interconnect device (MID) can be defined as an injection-molded plastic part that incorporates both electrical and mechanical functionalities in a single device. It is a relatively new area with enormous potential for industrial applications. At present, there are a number of available process chains for the manufacturing of MIDs. This paper presents a comparison among the MID manufacturing process chains, and it presents experimental results based on two of the most industrially adapted processes. Experiments with two-component (2k) injection molding and subsequent selective metallization show the dilemma between the polymer–polymer bond strength and selective metallization. Two new pairs of commercial polymer materials are introduced which are suitable for selective metallization and have the potential for industrial applications. Experiments with the laser direct structuring (LDS) process show that the success of the process is heavily dependant on the choice of material. It presents how the surface topographies are varied as a function of laser type and material choice. The amount of seed metal particles in the plastic material is a crucial factor that controls laser-induced metallization.     

Information requirements analysis for holonic manufacturing systems in a virtual environment

The design and development of holonic manufacturing systems requires careful, and sometimes risky, decision making to ensure that they will successfully satisfy the demands of an ever-changing market. In this paper, the authors propose a methodology for a holonic manufacturing systems requirement analysis that is based on a virtual reality approach and aimed at assisting designers of such systems along the entire systems design and development process. Exploiting virtual reality helps the user collect valid information quickly and in a correct form by putting the user and the information support elements in direct relation with the operation of the system in a more realistic environment. A prototype software system tool is designed to realise the features outlined in each phase of the methodology. A virtual manufacturing environment for matching the physical and the information model domains is utilised to delineate the information system requirements of holonic manufacturing systems implementation. A set of rules and a knowledge base is appended to the virtual environment to remove any inconsistency that could arise between the material and the information flows during the requirement analysis.     

Development of an management information system as knowledge base model for machining process characterisation

The current paper intends to use the typical problems of parameter selection and optimization in machining processes to bring out the design ideas that form the foundation of n-tier management information systems (MIS). These ideas can be used for creating data-driven, scalable enterprise information systems. The current phase (phase I) of the implementation highlights the capabilities of these design ideas in improving three key functional parameters of MIS, i.e. multi-dimensionality, isolation and scalability. The problem area of machining process characteristics of non traditional machining has been chosen with two specific goals in mind: A typical machining process has multiple parameters and various corresponding relationships can be found among such parameters. This will be used to highlight the degree of multi-dimensionality that can be achieved from a simple design pattern. The phase II of this paper can actually shift focus from the design of a generic management information system to a specific problem area of machining. This incorporates the features of an expert system in providing the customer or end user with maximum encapsulation of technical data and much improved decision-making capabilities within the system. Some complex machining processes such as abrasive water jet machining (AWJM), wire electrical discharge machining (WEDM) and electro discharge machining (EDM) are characterized by a large number of parameters which are not available in a structured fashion, thus, all the data associated with AWJM, WEDM and EDM systems has been conglomerated and presented in a normalized fashion. The essential features of the current research include the extraction of the relevant data from a large pool of data, with a distinct architecture of MIS, having three scalable layers. The normalization of the available data has been dealt with management information system and presented in the form of a software named “machining expert”. The code for the software provided is easy to understand, being written in Visual Basic and Access server for implementation. The developed “machining expert” for handling non traditional machining (NTM) data can also be extended with suitable design extensions to handle business logic by interacting with the end user. The current paper is applicable to any research on the structure and design of MIS in manufacturing technology.     

Development of graphical software for CIM applications

Flexibility, quality and cost advantages are three major factors motivating the introduction of CIM. However, lack of formalisms, tools, methodologies and organizational structures have slowed work in the CIM field. The development of application software capable of tailoring solutions to specific manufacturing problems from a set of existing and future CIM components, the automatic generation of friendly user interfaces to support individual user requirements, the design features that ensure the independence of application software, and the user interface software for accommodating changing manufacturing requirements are some of the key factors that determine the successful application of CIM. The Papillon prototype (developed under the ESPRIT research programme) presented here is based on sound software engineering principles, and has achieved an architecture which separates the application from the user interface, supports configurability of components and generates user interfaces without direct coding. Initially, pure application software with no graphics is built from a set of basic Papillon building blocks: graphical representations are then described by using the EASEL subsystem, and finally the user interface, which enables the user to ‘drive’ applications, is automatically generated. The EASEL subsystem is independent of the Papillon run-time system, and therefore different graphical user interfaces can be generated easily and evalauted at run-time with no need for recompilation. Fundamental concepts such as portability, configurability and reuse of methods and tools are major considerations in the overall design and implementation of the Papillon system. Although the primary emphasis is on CIM, the generic design of the Papillon system makes it an ideal environment for the development of graphical software for a wide range of applications in several fields.     

Determining transfer batch sizes in trip-based material handling systems

Trip-based material handling systems such as AGV systems or lift trucks are often designed with a given flow matrix (or from-to chart), which typically shows the number of loaded trips that the devices must perform per unit time between the workstations. A from-to chart that would result from the parts flow in a facility actually is dictated by the transfer batch size; that is, the number of parts transferred from one workstation to the next in one trip. In this paper, we present analytical and simulation results aimed at determining optimal or nearoptimal transfer batch sizes in manufacturing systems and develop an analytical relationship between the material handling capacity and the expected work in process (WIP) in a manufacturing system. Although the results apply to any discrete-parts flow, trip-based material handling system, they are particularly relevant for the electronics manufacturing industry, where parts (such as printed circuit boards or substrates for flat panel displays) typically are handled as a group (in specially designed containers such as cassettes) and the costs associated with WIP tend to be large. In such applications, the cassette size is the transfer batch size.     

A concurrent manufacturing strategy for One-of-a-Kind Products with complicated sculptured surfaces

In this paper, we propose a computer-aided system for concurrently designing and manufacturing a customised or One-of-Kind Production (OKP) mould or die which has complicated sculptured surfaces. Considering the OKP production characteristics of high customisation and concurrent product development and production, we believe that the concurrent consideration of both the design and the manufacturability of a mould or a die would be necessary. This concurrence can be realised by providing timely manufacturability information feedback after a design is completed or a feature is modified or added in the design. The other problem is that the sculptured surface geometry model of a mould or a die does not contain any machining information. Hence we developed an intermediate data model for capturing manufacturing features when we are modelling the geometric form of a mould or a die. The system is based on CADDS5 which is a commercial CAD/CAM system. Two modules for data extraction, coverting and modelling as well as for manufacturability analysis have been developed and added to CADDS5. Using this computer-aided system; a designer can interrogate geometry and machining constraint information through a user friendly interface to avoid defects and inefficiency resulting from an earlier design, and can finalise the design by making quick incremental adjustments. The system has been implemented in a mould and die manufacturing company in China. This implementation leads to less rework and shorter lead time.     

An integrated manufacturing information system for mass sheet metal cutting

In order to reduce manufacturing cost and to improve the operational efficiency, some factories in the sheet-metal-related manufacturing industry centralize the production and management of sheet metal cutting. To support the centralized mass manufacturing paradigm, this paper presents an integrated manufacturing information system to achieve the high utilization of raw sheet material, lower the manufacturing cost, as well as to improve the operational efficiency and production management. The system architecture and some key technologies to implement this system are investigated, based on which, the whole information system is developed. This system integrates the functions of sheet metal part modeling and unfolding, nesting planning, automatic and interactive nesting, cutting process planning, NC-programming, off-line processing simulation and on-line monitoring. The system has been successfully utilized in industry, and an example of its application is described in the paper.     

Advanced RFID application for a mixed-product assembly line

Due to its scale, complexity, and uncertainty of the processes, the management and control of automotive manufacturing systems have been very challenging. With the recent application of new technologies such as radio frequency identification (RFID) to manufacturing process, real-time information has become available in manufacturing systems through IT infrastructures. It is expected that RFID-based real-time information will increase timeliness and efficiency in decision making and drastically reduce uncertainty. That, in turn, will enhance both productivity and quality. This paper presents an advanced RFID application for automotive assembly processes, specifically, dynamic material dispatching (e.g., auto assembly parts). The application is uniquely advanced in that it integrates RFID technology with a real-time decision support system to ensure the accurate and efficient delivery of auto parts to mixed-product assembly lines. In this application, we have described the problem as a mixed-integer programming model, proposed a heuristic algorithm that incorporates the available RFID information, and assessed the value of RFID through a scenario-based analysis. We hope this paper may help contribute to a virtuous cycle of RFID innovation and applications in the manufacturing sector.     

交互式虚拟设计与同步制造技术算法与图形系统研究

产品的创意外形设计与快速试制对于更好地满足产品多品种、短开发周期、优美外形、提高市场竞争力等需求具有重要意义,而现有的CAD/CAM和快速原型制造技术在这一方面仍然存在一些不足,这里提出的交互式虚拟设计与同步试制系统利用虚拟现实技术和计算机数字雕刻技术,在交互设计、创意设计、快速试制、材料多样性等方面都有所突破。文章阐述了在设计过程中工作描述、刀具轨迹包络计算、图形布尔运算、以及高速逼真图形显示等关键技术。实际工作设计与制造实验证明所开发的系统技术可行,已经可以进行基本的产品外形设计与同步制造。     

Improvements on time-resolved measurement of gas volume production in laboratories bench systems

We propose improvements to a time-resolved gas volume meter based on bubble count. This type of sensor is dedicated to small-scale laboratory applications, usually related to gas production in biological processes. We highlight the cost reduction and simplification in the manufacturing method of this type of sensor, when compared to the manufacturing method. To achieve this purpose, the sensor’s glass body was replaced by plastic material, a detection system based on the detection of capacitance variation was introduced and without contact with the measuring fluid, the data acquisition system was built based on small single-board computer and a graphical user interface were developed in an open source programming language. Theses innovations are significant for scientific research institutions, with limited financial resources, to uses gas volume sensors that can be applied in the investigation of biological processes such as alcoholic fermentation, biogas and biohydrogen generation.     

Design of Components and Layout of Machines for Material Handling

Efficient material handling can reduce the amount of work in manufacturing operations. This paper discusses the design of components and the layout of machines from a material handling perspective. A way to reduce the material handling cost without compromising the component functionality is to choose satisfactory design options. The relationships between the design of the components and material handling are analysed to reduce the flow of material in a manufacturing system. In Model I, component routes are selected for a potential manufacturing system when only limited information regarding the layout of the machines is available. The selection of component routes is integrated with the determination of machine locations, the layout of single-row machines, and the layout of multi-row machines with equal areas, respectively, in Model II. Each problem is mathematically formulated and two algorithms are presented with illustrative examples.     

Dissimilar metal deposition with a stainless steel and nickel-based alloy using wire and arc-based additive manufacturing

The wire and arc-based additive manufacturing process applies arc welding technology; the wire material is melted by the arc discharge, and is then accumulated successively in this process. The wire and arc-based additive manufacturing process directly and locally adds material to the molten pool. By changing the material locally during the process, more than one kind of material can be used simultaneously in a single manufactured component. In this study, two kinds of dissimilar metal deposition were conducted. A combination used was a stainless steel and Ni-based alloy. Mechanical properties near the interface such as hardness and bond strength were investigated. As a result, it was found that the mechanical properties of the manufactured alloy were comparable to those of a bulk material. In addition, an additive manufacturing system and a torch path planning method for using more than two kinds of material were proposed. By using this method, highly functional shapes whose surfaces and inner structures are made of different material could be made.     

Classification and modeling for in-plant milk-run distribution systems

Material handling is one of the most important issues that should be taken into account for eliminating waste and reducing the cost. It is one of the seven wastes defined in the concept of lean manufacturing. In this study, for a lean material handling system under the lean manufacturing conditions such as pull-based and repetitive manufacturing, a system consisting of periodically moving vehicles in certain routes is taken into consideration. This system is also called milk-run distribution system. Application of milk-run distribution systems in plants standardizes the material handling system and eliminates the waste. Although there are huge numbers of studies related with inbound and outbound logistics, there are few studies especially related with milk-run applications in the manufacturing area. Within this study, based on the observations in real manufacturing environment and limited literature, the milk-run distribution problem in the plants is categorized and explained. For one of the main categories, modeling is performed. The objective of the developed models is to minimize the number of vehicles and the distance traversed. A numerical example inspired by real applications is presented for showing the applicability of the developed models.     

Extraction of manufacturing information from design-by-feature solid model through feature recognition

Feature recognition is the key to the computer-aided design (CAD) and computer-aided manufacturing (CAM) integration to build a computer-integrated manufacturing system. There are two approaches to CAD feature recognition: platform-dependent and platform-independent. In the platform-independent approach, the part’s geometrical data are extracted from a neutral file such as DXF, IGES, or STEP. In contrast, the platform-dependent approach extracts the information of the design features directly from a design-by-feature solid model through the object-oriented model of a part. This paper explains a platform-dependent approach which is implemented to translate design features into manufacturing information. This approach begins with simplification using the suppression of fillets, and clustering non-intersecting design features is done. Then, the rule-based method is employed in order to recognize machining features. Finally, the needed manufacturing information such as tool accessing direction, dimensions, material removal regions, and geometrical and topological data is recognized. The application of the proposed system would be exhibited in generating machine path code for rapid prototyping and CNC machines and providing a database for computer-aided process planning. The proposed system was implemented on Autodesk Inventor and successfully tested for many complex 3D models.     

A structured approach to the automatic planning of machining operations for rotational parts based on computer integration of standard design and process data

The traditional procedure for developing a manufacturing process plan involves a number of interconnected steps beginning with the initial design and culminating in the instructions for the machine that makes the part. When performed manually, the procedure is very tedious, time consuming, and often, inconsistent. This paper presents an alternative method, called the Automated Machining-Operations Process-Planning System (AMOPPS), to automatically generate the process plan and the numerical control (NC) instructions to machine a part that has been previously designed by a computer-aided design (CAD) system. AMOPPS combines preset planning logic and data from three databases (viz., workpiece material, machine tool, and cutting tool) with appropriate data from a CAD database and information from the user about the workpiece to calculate the optimal machining parameters, print a process plan, print the corresponding NC program listing, and provide an on-screen animation of the cutting passes. Although AMOPPS is a prototype, it can be extended by adding other modules, and it does provide a structure through which a fully integrated manufacturing system can be developed.     

A combined additive manufacturing and micro-syringe deposition technique for realization of bio-ceramic structures with micro-scale channels

This article presents a novel rapid layered manufacturing approach based on a combined additive manufacturing (AM) process and a UV-based micro-syringe deposition (μSD) technique to be used in the fabrication of bio-ceramic structures with controlled micro-sized channels for bone and osteochondral tissue regeneration. In the proposed rapid manufacturing method, micro-scale sacrificial photopolymer networks are integrated within the manufactured part by depositing the photopolymer on selected bio-ceramic powder layers using an injection system. This AM–μSD method along with a post-processing protocol can potentially overcome current limitations of traditional powder-based AM approaches that are restricted in terms of complexity of internal architecture and feature size. For bone or osteochondral repair applications, the material system composed of the bio-ceramic and sacrificial photopolymer, along with the post-processing protocol, must ensure that the final implants are free from manufacturing residuals that could trigger an immune response post-implantation. In this study, calcium polyphosphate bio-ceramic was used as the substrate material based on prior art, polyvinyl alcohol solution was used as the powder binding agent, and ethoxylated (10 bisphenol A diacrylate) photopolymer solution was used as the sacrificial photopolymer element. Material characterization suggests that the proposed material system along with heat treatment protocol is suitable for the targeted applications where micro-scale channels within the implant are produced by AM–μSD.     

A digraph-based expert system for non-traditional machining processes selection

The presence of a number of available non-traditional machining (NTM) processes has brought out the idea of selecting the most suitable NTM process for generating a desired shape feature on a given work material. This paper presents a digraph-based approach to ease out the appropriate NTM process selection problem. It includes the design and development of an expert system that can automate this decision-making process with the help of graphical user interface and visual aids. The proposed approach employs the use of pair-wise comparison matrices to calculate the relative importance of different attributes affecting the NTM process selection decision. Based on the characteristics and capabilities of the available NTM processes to machine the required shape feature on a given work material, the permanent values of the matrices related to those processes are computed. Finally, if some of the NTM processes satisfy a certain threshold value, those are shortlisted as the acceptable processes for the given shape feature and work material combination. The digraph-based expert system not only segregates the accepted NTM processes from the list of the available processes but also ranks them in decreasing order of preference. It also helps the user as a responsible guide to select the most suitable NTM process by incorporating all the possible error trapping mechanisms. This paper takes into account some new work materials, shape features and NTM processes that have not been considered by the earlier researchers. It is further observed that the developed expert system is quite flexible and versatile as the results of the cited examples totally corroborate with those obtained by the past researchers.     

The implementation of a cell-based manufacturing system

This paper describes the development of a cell-based manufacturing system. It considers all aspects of the implementation: the initial analysis of the problems of an existing system, product redesign for manufacture, cell design and cell implementation. The effectiveness of the resulting system is measured, using quantitative parameters. These include manufacturing lead times, due date performance and inventory levels. Other features, such as increased product quality, increased customer satisfaction and increased worker satisfaction, which cannot be measured easily, are discussed and shown to be major factors behind the successful implementation. Although presented as a case study the procedures adopted to facilitate the successful implementation are of general interest to any prospective manufacturing cell user.     

Developing an end-of-arm tooling for robotic grinding machining application

Cleaning castings is a common process in manufacturing and there have been various kinds of robotic applications in deburring, polishing, etc. However, robots have not been applied to surface machining because of difficulties in metal removal control. Robotic Vision Systems Inc. is currently engaged in a research effort to develop a robotic disc or wheel grinding unit for surface machining applications. Novel design features, such as passive compliance and visual feedback, will provide system performance that offers more consistent quality and lower production costs than manual methods.