An integrated computer-aided modular fixture design system for machining semi-circular parts

Productivity is one of the most important factors in manufacturing processes because of the high level of market competition. In this regard, modular fixtures (MFs) play an important role in practically improving productivity in flexible manufacturing systems (FMSs) due to this technology using highly productive computer numerical control (CNC) machines. MFs consist of devices called jigs and fixtures for accurately holding the workpiece during different machining operations. The design process is complex, and traditional methods of MF design were not sufficiently productive. Computer-aided design (CAD) software has rapidly improved as a result of the development of computer technology, and has provided huge opportunities for modular fixture designers to use its 3D modelling capabilities to develop more automated systems. Computer-aided fixture design (CAFD) systems have become automated by the use of artificial intelligence (AI) technology. This study will investigate the further improvement of automated CAFD systems by using AI tools. In this research, an integrated CAFD is developed by considering four main requirements: · a 3D model of the workpiece, · an expert system, · assembly automation of MFs, · an efficient feature library. The 3D model is an important factor that can provide the appropriate specification of the workpiece; SolidWorks is used the CAD environment for undertaking the 3D modelling in this study. The expert system is applied as a tool to make right decisions about the CAFD planning process, including locating and clamping methods and their related element selection. This helps achieve a feasible fixture design layout. SolidWorks API and Visual Basic programming language are employed for the automating and simulation of the assembly process of MFs. A feature library of modular fixture elements is constructed as a means to simplify the fixture design process

Fixturing information models in data model-driven product design and manufacture

In order to ensure effective decisions are made at each stage in the design and manufacture process, it is important that software tools should provide sufficient information to support the decision making of both designers and manufacturing engineers. This requirement can be applied to fixturing where research to date has typically focused on narrow functional support issues in fixture design and planning. The research reported in this thesis has explored how models of fixturing information can be defined, within an integrated information environment, and utilised across product design as well as manufacture. The work has focused on the definition of fixturing information within the context of a wide-ranging model that can capture the full capability of a manufacturing facility. [Continues.

The effects of an interactive computerized multimedia tutorial on knowledge gain in modular fixturing design concepts

This study was designed to compare student knowledge gain from learning modular fixturing design concepts by computer tutorial versus traditional lecture. The use of computer tutorial to support engineering and technology classroom instructions has been a major issue for many studies. The undergraduate curricula in engineering and technology are becoming increasingly complex due to the today\u27s modern wide variety of manufacturing processes. The concept of modular fixturing in tool design course is one of the technical competencies which most industries would like graduates to be able to apply their knowledge to real-world problems and situations. An interactive computerized multimedia tutorial named ToolTRAIN was developed and administered to undergraduate students in the Industrial Technology program at the University of Northern Iowa. By integrating information in a graphical manner such as 3D visualization through animation, ToolTRAIN demonstrated how several modular fixturing components can be assembled with a wide variety of workpieces. A quasi-experimental design employing pre- and post-instruction tests was utilized for the study. Two preexisting groups of students were assigned to either the experimental or control group. Both groups were instructed on the same general topics covered in this study. A pretest was given to both groups. Three hours were used to teach the control group the concepts and theories of modular fixturing design concepts by lecture. On the other hand, the experimental group was expected to utilize ToolTRAIN for three hours. The posttest was administered to all subjects to measure knowledge gain of modular fixturing design concepts after the instruction. The data were analyzed using t tests to compare group mean of change scores. All hypotheses were tested at the .05 level of significance. This research indicated that there were significant differences between the computer tutorial program and lecture method. The experimental (computer tutorial) group achieved significantly higher improvement in scores than the control (lecture) group. Also, the learning time actually spent using ToolTRAIN was less that for the control group. Based on this research it was concluded that the ToolTRAIN interactive multimedia tutorial program can be used as an effective teaching method for modular fixturing design concepts. Future research should expand the sample size used in the investigation with tighter control of control group module content. ToolTRAIN can also be used for more complex concepts of modular fixturing system and applications

Machine planning in a product model environment

The aim of this research was to understand and solve problems associated with the integration of a Machine Planner within a product model environment. This work was carried out in conjunction with other researchers, pursuing parallel integration issues related to pre-production proving and product data representation. Product data representations of component level planned, processes and feature level process data have been explored as sub-sets of -a product data model to aid integration. Geometric queries on a cell decomposition solid, model. have been explored as a means of providing feature geometric interaction data, while the dimensional interactions between features have also been addressed. Product data representations have been modelled using a prototype software tool, providing an environment for the exploration of the integration of a Machine Planner using a feature based design approach. Necessary Machine Planning functions have been implemented, using the ADA programming language, to explore the integrating capability of the product model environment, concentrating on the use of a prismatic benchmark component. Using the experimental implementation, setup and operation plans have been produced and machining part programs generated from product model representations of variants on the benchmark component. These have been successfully machined using a3 axis vertical machining centre. Such experiments, as well as others in conjunction with co-researchers, have shown that a product data model can provide a common base of data for the integration of a range of design and manufacturing activities

A multi-objective flexible manufacturing system design optimization using a hybrid response surface methodology

The present study proposes a hybrid framework combining multiple methods to determine the optimal values of design variables in a flexible manufacturing system (FMS). The framework uses a multi-objective response surface methodology (RSM) to achieve optimum performance. The performance of an FMS is characterized using various weighted measures using the best-worst method (BWM). Subsequently, an RSM approximates the functional relationship between the FMS performance and design variables. The central composite design (CCD) is used for this aim, and a polynomial regression model is fitted among the factors. Eventually, a bi-objective model, including the fitted and cost functions, is formulated and solved. As a result, the optimal percentage for deploying the FMS equipment and machines to achieve optimal performance with the lowest deployment cost is determined. The proposed framework can serve as a guideline for manufacturing organizations to lead strategic decisions regarding the design problems of FMSs. It significantly increases productivity for the manufacturing system, reduces redundant labor and material handling costs, and facilitates productio

Computer-aided process planning (CAPP) SORICH

The last two decades have witnessed the increasing role of the computer in the process planning function. This has been further enhanced by the advent of the knowledge based expert system, and its impact on Computer Aided Process Planning (CAPP). CAPP has emerged as a strategic link between design and manufacture. This thesis discusses the various methods used in the process planning function. Group Technology (GT) plays a pivotal role in establishing CAPP. The utilization of Artificial Intelligence techniques in CAPP is listed. This study also presents an Interactive Software adaptive to product/part configuration variables

Automatic assembly of versatile fixtures

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Virtual reality for fixture design and assembly

Due to today's heavy, growing competition environment, manufacturing companies have to develop and employ new emerging technologies to increase productivity, reduce production costs, improve product quality, and shorten lead time. The domain of Virtual Reality (VR) has gained great attention during the past few years and is currently explored for practical uses in various industrial areas e.g. CAD, CAM, CAE, CIM, CAPP and computer simulation etc. Owing to the trend towards reducing lead time and human effort devoted to fixtureplanning, the computerization of fixture design is required. Consequently, computer aided fixture design (CAFD) has become an important role of computer aided design/manufacture (CAD/CAM integration. However, there is very little ongoing research specially focused on using the VR technology as a promising solution to enhance CAFD systems' capability and functionality. This thesis reviews the possibility of using interactive Virtual Reality (VR) technology to support the conventional fixture design and assembly process. The trend that the use of VR benefits to fulfil the optimization of fixture design and assembly in VE has been identified and investigated. The primary objectives were to develop an interactive VR system entitled Virtual Reality Fixture Design & Assembly System (VFDAS), which will allow fixture designers to complete the entire design process for modular fixtures within the Virtual Environment (VE) for instance: Fixture element selection, fixture layout design, assembly, analysis and so on. The main advantage of VFDAS is that the VR system has the capability of simulating the various physical behaviours for virtual fixture elements according to Newtonian physical laws, which will be taken into account throughout the fixture design and evaluation process. For example: gravity, friction, collision detection, mass, applied force, reaction force and elasticity. Almost the whole fixture design and assembly process is achieved as if in the real physics world, and this provides a promise for computer aided fixture design (CAFD) in the future. The VFDAS system was validated in terms of the collision detection, rendering speed, friction, mass, gravity, applied force, elasticity and toppling. These simulation results are presented and quantified by a series of simple examples to show what the system can achieve and what the limitations are. The research concluded VR is a useful technology and VFDAS has potential to support education and application for fixture design. There is scope for further development to add more useful functionality to the VFDAS system

Virtual reality for fixture design and assembly

Due to today's heavy, growing competition environment, manufacturing companies have to develop and employ new emerging technologies to increase productivity, reduce production costs, improve product quality, and shorten lead time. The domain of Virtual Reality (VR) has gained great attention during the past few years and is currently explored for practical uses in various industrial areas e.g. CAD, CAM, CAE, CIM, CAPP and computer simulation etc. Owing to the trend towards reducing lead time and human effort devoted to fixtureplanning, the computerization of fixture design is required. Consequently, computer aided fixture design (CAFD) has become an important role of computer aided design/manufacture (CAD/CAM integration. However, there is very little ongoing research specially focused on using the VR technology as a promising solution to enhance CAFD systems' capability and functionality. This thesis reviews the possibility of using interactive Virtual Reality (VR) technology to support the conventional fixture design and assembly process. The trend that the use of VR benefits to fulfil the optimization of fixture design and assembly in VE has been identified and investigated. The primary objectives were to develop an interactive VR system entitled Virtual Reality Fixture Design & Assembly System (VFDAS), which will allow fixture designers to complete the entire design process for modular fixtures within the Virtual Environment (VE) for instance: Fixture element selection, fixture layout design, assembly, analysis and so on. The main advantage of VFDAS is that the VR system has the capability of simulating the various physical behaviours for virtual fixture elements according to Newtonian physical laws, which will be taken into account throughout the fixture design and evaluation process. For example: gravity, friction, collision detection, mass, applied force, reaction force and elasticity. Almost the whole fixture design and assembly process is achieved as if in the real physics world, and this provides a promise for computer aided fixture design (CAFD) in the future. The VFDAS system was validated in terms of the collision detection, rendering speed, friction, mass, gravity, applied force, elasticity and toppling. These simulation results are presented and quantified by a series of simple examples to show what the system can achieve and what the limitations are. The research concluded VR is a useful technology and VFDAS has potential to support education and application for fixture design. There is scope for further development to add more useful functionality to the VFDAS system