The Experts below are selected from a list of 43107 Experts worldwide ranked by ideXlab platform
A. Dominek - One of the best experts on this subject based on the ideXlab platform.
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Parameter de-embedding accuracy dependency upon material sample dimensions
IEEE Transactions on Microwave Theory and Techniques, 1992Co-Authors: A. Park, A. DominekAbstract:The sensitivity of the sample fit in rectangular waveguide Fixtures is examined for constitutive parameter de-embedding. The sensitivity is characterized through a percent error figure between the de-embedded and known parameter values when an air gap exists between the sample and the side walls of the Fixture. The de-embedding process assumed a completely filled waveguide in which rigorously calculated S parameters for material sample air gaps in either the E- or H-plane walls of the waveguide were used. The presence of an air gap was very noticeable for a E-plane gap. Commonly used gap correction factors provided limited improvement in reducing air gap related errors. >
A. J. C. Trappey - One of the best experts on this subject based on the ideXlab platform.
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Computer-aided Fixture design system for comprehensive modular Fixtures
International Journal of Production Research, 2001Co-Authors: J.l. Hou, A. J. C. TrappeyAbstract:Fixture design plays an important role at the planning stage before shop-floor production. A desired Fixture design can be employed to hold the workpart securely so that slippage and excessive deformation can be prevented during machining. Therefore, appropriate fixturing contributes highly to machining quality. To reduce lead time and the human effort devoted to Fixture planning, computer-aided Fixture design (CAFD) is required. In this paper, a CAFD system consisting of three modules, i.e. Fixture Data Management, Fixture Element Selection and Fixture Layout Design, is developed. According to Fixture feature recognition and classification, a comprehensive Fixture database in the Fixture Data Management module is constructed to maintain efficiently the Fixture-related data. The domain of the Fixture database consists of modular mechanical Fixtures, modular hydraulic Fixtures and modular V-blocks. After expertise extraction, suitable Fixture elements can be automatically selected according to the machinin...
A. Park - One of the best experts on this subject based on the ideXlab platform.
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Parameter de-embedding accuracy dependency upon material sample dimensions
IEEE Transactions on Microwave Theory and Techniques, 1992Co-Authors: A. Park, A. DominekAbstract:The sensitivity of the sample fit in rectangular waveguide Fixtures is examined for constitutive parameter de-embedding. The sensitivity is characterized through a percent error figure between the de-embedded and known parameter values when an air gap exists between the sample and the side walls of the Fixture. The de-embedding process assumed a completely filled waveguide in which rigorously calculated S parameters for material sample air gaps in either the E- or H-plane walls of the waveguide were used. The presence of an air gap was very noticeable for a E-plane gap. Commonly used gap correction factors provided limited improvement in reducing air gap related errors. >
A. Senthil Kumar - One of the best experts on this subject based on the ideXlab platform.
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A study on automatic Fixture design using reinforcement learning
The International Journal of Advanced Manufacturing Technology, 2020Co-Authors: Darren Wei Wen Low, Dennis Wee Keong Neo, A. Senthil KumarAbstract:Fixtures are used to locate and secure workpieces for further machining or measurement process. Design of these Fixtures remains a costly process due to the significant technical know-how required. Automated Fixture design can mitigate much of these costs by reducing the dependence on skilled labour, making it an attractive endeavour. Historical attempts in achieving automated Fixture design solutions predominantly relied on case-based reasoning (CBR) to generate Fixtures by extrapolating from previously proven designs. These approaches are limited by their dependence on a fixturing library. Attempts in using rule-based reasoning (RBR) has also shown to be difficult to implement comprehensively. Reinforcement learning, on the other hand, does not require a fixturing library and instead builds experience and learns through interacting with an environment. This paper discusses the use of reinforcement learning to generate optimized fixturing solutions. Through a proposed reinforcement learning driven Fixture design (RL-FD) framework, reinforcement learning was used to generate optimized fixturing solutions. In response to the fixturing environment, adjustments to the reinforcement learning process in the exploration phase is studied. A case study is presented, comparing a conventional exploration method with an adjusted one. Both agents show improved average results over time, with the adjusted exploration model exhibiting faster performance.
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IFDA: an interactive Fixture design and assembly environment
Journal of Computer Applications in Technology, 2014Co-Authors: Jerry Y. H. Fuh, Andrew Y. C. Nee, A. Senthil Kumar, J.c.s. TeoAbstract:In the development of a Fixture design system, an important element is building a modular Fixture database that can be integrated with a CAD system. This paper describes the architecture and the details in developing an interactive Fixture design and assembly (IFDA) environment that interfaces with Hewlett–Packard (HP) ME30 solid modeller and a Fixture–elements database based on a hole–matrix modular fixturing system, namely Bluco Technik. The menu layout of the IFDA environment was designed to include the four categories of Fixture elements, i.e. base plates, locators, clamps, and accessories. The modular Fixture elements, displayed in bit–mapped graphics together with its key attributes, can be retrieved from the database and be assembled in the CAD system. The Motif–based graphical user interface (GUI) design makes it easier to design a modular Fixture on–screen. The interactive nature helps Fixture designers to select and verify Fixture elements from a catalogue database before assembling and constructing them. The information stored by the IFDA environment can be used for automated retrieval and assembly of modular Fixtures.
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Automatic generation of dynamic clamping forces for machining Fixtures
International Journal of Production Research, 1999Co-Authors: Z J Tao, A. Senthil Kumar, Andrew Y. C. NeeAbstract:Automatic Fixture configuration analysis is an essential issue in the context of computer-integrated manufacturing. In this paper, a general methodology for Fixture configuration verification is presented, which is based on force closure and clamping equilibrium. The inclusion of a new clamping equilibrium criterion ensures a robust clamping layout and hence reduces the possibility of workpiece displacement within a Fixture. For clamping force analysis, a new method for directly generating the minimal clamping intensity for planar Fixtures is presented. Next, we develop a general friction methodology of dynamic clamping analysis and planning for arbitrary-shaped workpieces based on nonlinear programming. The objective of the presented algorithm is to determine a spectrum of minimum sustainable clamping forces for a machining process based on a proposed criterion of maximum friction. The set of variable clamping intensities is determined such that it is just enough to counterbalance the dynamic cutting for...
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An approach to automating modular Fixture design and assembly
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 1997Co-Authors: J R Dai, Andrew Y. C. Nee, Jerry Y. H. Fuh, A. Senthil KumarAbstract:In the development of a modular Fixture design system, it is essential to have a modular Fixture element database that can be integrated with a CAD system, in addition to the other considerations such as Fixture configuration, interference checking, etc., which are also important to Fixture designers. This paper describes a new method to create the Fixture element database and model the fixturing towers (i.e. subassemblies). By using this method, the database can be effectively created and is easy for use in Fixture assembly. The modular Fixture tower database is used to represent the subassembly of Fixtures. This will simplify the Fixture design and assembly process. A built-in interference checking methodology is embedded in the planning stage that will ensure a collision-free Fixture design. The system is developed using the knowledge-based system, ICAD, and interfacing with UG-II for modelling the workpiece. Examples of Fixture design generated by the system are also provided to illustrate the development.
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Future Trends and Developments in Fixturing Methodologies
Advanced Fixture Design for FMS, 1995Co-Authors: Andrew Y. C. Nee, K. Whybrew, A. Senthil KumarAbstract:Advances in the technology of flexible manufacturing systems, and the introduction of concurrent engineering of product and process design have propounded the need for computer aided Fixture design systems. Computer aided process planning is the interface between design and manufacturing and has a key role in achieving integration between the various modules in an FMS environment. Fixture design is inseparable from process planning, and hence to be of practical use any CAPP system must include Fixture design. The past few years have seen great advances in automated Fixture design systems and the tools used to achieve them. With the exception of Fixture design for a limited range of products with close family similarity, fully automated design of practical Fixtures is not yet achievable. The advances described in this book have widened the scope of application of computer aided Fixture design and provide enhanced links with other product and process design activities.
Andrew Y. C. Nee - One of the best experts on this subject based on the ideXlab platform.
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IFDA: an interactive Fixture design and assembly environment
Journal of Computer Applications in Technology, 2014Co-Authors: Jerry Y. H. Fuh, Andrew Y. C. Nee, A. Senthil Kumar, J.c.s. TeoAbstract:In the development of a Fixture design system, an important element is building a modular Fixture database that can be integrated with a CAD system. This paper describes the architecture and the details in developing an interactive Fixture design and assembly (IFDA) environment that interfaces with Hewlett–Packard (HP) ME30 solid modeller and a Fixture–elements database based on a hole–matrix modular fixturing system, namely Bluco Technik. The menu layout of the IFDA environment was designed to include the four categories of Fixture elements, i.e. base plates, locators, clamps, and accessories. The modular Fixture elements, displayed in bit–mapped graphics together with its key attributes, can be retrieved from the database and be assembled in the CAD system. The Motif–based graphical user interface (GUI) design makes it easier to design a modular Fixture on–screen. The interactive nature helps Fixture designers to select and verify Fixture elements from a catalogue database before assembling and constructing them. The information stored by the IFDA environment can be used for automated retrieval and assembly of modular Fixtures.
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Automatic generation of dynamic clamping forces for machining Fixtures
International Journal of Production Research, 1999Co-Authors: Z J Tao, A. Senthil Kumar, Andrew Y. C. NeeAbstract:Automatic Fixture configuration analysis is an essential issue in the context of computer-integrated manufacturing. In this paper, a general methodology for Fixture configuration verification is presented, which is based on force closure and clamping equilibrium. The inclusion of a new clamping equilibrium criterion ensures a robust clamping layout and hence reduces the possibility of workpiece displacement within a Fixture. For clamping force analysis, a new method for directly generating the minimal clamping intensity for planar Fixtures is presented. Next, we develop a general friction methodology of dynamic clamping analysis and planning for arbitrary-shaped workpieces based on nonlinear programming. The objective of the presented algorithm is to determine a spectrum of minimum sustainable clamping forces for a machining process based on a proposed criterion of maximum friction. The set of variable clamping intensities is determined such that it is just enough to counterbalance the dynamic cutting for...
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An approach to automating modular Fixture design and assembly
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 1997Co-Authors: J R Dai, Andrew Y. C. Nee, Jerry Y. H. Fuh, A. Senthil KumarAbstract:In the development of a modular Fixture design system, it is essential to have a modular Fixture element database that can be integrated with a CAD system, in addition to the other considerations such as Fixture configuration, interference checking, etc., which are also important to Fixture designers. This paper describes a new method to create the Fixture element database and model the fixturing towers (i.e. subassemblies). By using this method, the database can be effectively created and is easy for use in Fixture assembly. The modular Fixture tower database is used to represent the subassembly of Fixtures. This will simplify the Fixture design and assembly process. A built-in interference checking methodology is embedded in the planning stage that will ensure a collision-free Fixture design. The system is developed using the knowledge-based system, ICAD, and interfacing with UG-II for modelling the workpiece. Examples of Fixture design generated by the system are also provided to illustrate the development.
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Future Trends and Developments in Fixturing Methodologies
Advanced Fixture Design for FMS, 1995Co-Authors: Andrew Y. C. Nee, K. Whybrew, A. Senthil KumarAbstract:Advances in the technology of flexible manufacturing systems, and the introduction of concurrent engineering of product and process design have propounded the need for computer aided Fixture design systems. Computer aided process planning is the interface between design and manufacturing and has a key role in achieving integration between the various modules in an FMS environment. Fixture design is inseparable from process planning, and hence to be of practical use any CAPP system must include Fixture design. The past few years have seen great advances in automated Fixture design systems and the tools used to achieve them. With the exception of Fixture design for a limited range of products with close family similarity, fully automated design of practical Fixtures is not yet achievable. The advances described in this book have widened the scope of application of computer aided Fixture design and provide enhanced links with other product and process design activities.
