A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, ag...A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, agent oriented programming language, knowledge representation and reasoning strategy. The system can produce the technological file and technological quota, which can satisfy the production needs of factory.展开更多
Process planning and scheduling are two major plann in g and control activities that consume significant part of the lead-time, theref ore all attempts are being made to reduce lead-time by automating them. Compute r ...Process planning and scheduling are two major plann in g and control activities that consume significant part of the lead-time, theref ore all attempts are being made to reduce lead-time by automating them. Compute r Aided Process Planning (CAPP) is a step in this direction. Most of the existin g CAPP systems do not consider scheduling while generating a process plan. Sched uling is done separately after the process plan has been generated and therefore , it is possible that a process plan so generated is either not optimal or feasi ble from scheduling point of view. As process plans are generated without consid eration of job shop status, many problems arise within the manufacturing environ ment. Investigations have shown that 20%～30% of all process plans generated are not valid and have to be altered or suffer production delays when production sta rts. There is thus a major need for integration of scheduling with computer aide d process planning for generating more realistic process plans. In doing so, eff iciency of the manufacturing system as a whole is expected to improve. Decision support system performs many functions such as selection of machine too ls, cutting tools, sequencing of operations, determination of optimum cutting pa rameters and checking availability of machine tool before allocating any operati on to a machine tool. The process of transforming component data, process capabi lity and decision rules into computer readable format is still a major obstacle. This paper proposes architecture of a system, which integrates computer aided p rocess-planning system with scheduling using decision support system. A decisio n support system can be defined as " an interactive system that provides the use rs with easy access to decision models in order to support semi-structured or u nstructured decision making tasks".展开更多
Computer aided inspection planning (CAIP) is one of the key quality assurance techniques in CIMS.CAIP generates inspection process data based on the product design requirements. Therefore, a unified product informatio...Computer aided inspection planning (CAIP) is one of the key quality assurance techniques in CIMS.CAIP generates inspection process data based on the product design requirements. Therefore, a unified product information model should be used to share product data with the CAD system. As a data exchange standard coveringthe complete product fife cycle, STEP could be used to integrate data transfer between CAD and CAIP. An inspection oriented mechanical product information model (IOMPIM ) is proposed in this paper. It includes form features,dimensional and tolerance information and uses EXPRESS for information modeling. The STEP pre-processor andpost-processor have been developed to transfer product model information between CAD and CAIP using the STEPneutral file. In preliminary system tests, product information for many complex parts was transferred through theCIMS environment with the CAIP system generating rational inspection processes. A coordinate measuring machinewas then used for quality inspection of the parts.展开更多
THCAPP is a computer aided process planning system for non-rotational parts which runs in a CIMS (computer integrated manufacturing system ) environment at Tsinghua University. Its architecture is described in this pa...THCAPP is a computer aided process planning system for non-rotational parts which runs in a CIMS (computer integrated manufacturing system ) environment at Tsinghua University. Its architecture is described in this paper. Then its main functions and key techniques, including part modeling, generative process planning and integration with CAD (computer aided design) and CAM (computer aided manufacturing) ale discussed in detail.展开更多
Computer aided process planning (CAPP) aims at improving efficiency, quality, and productivity in a manufacturing concern through reducing lead times and costs by utilizing better manufacturing practices thus improvin...Computer aided process planning (CAPP) aims at improving efficiency, quality, and productivity in a manufacturing concern through reducing lead times and costs by utilizing better manufacturing practices thus improving competitiveness in the market. CAPP attempts to capture the thoughts and methods of the experienced process planner. Variant systems are understandable, generative systems can plan new parts. Expert systems increase flexibility, fuzzy logic captures vague knowledge while neural networks learn. The combination of fuzzy, neural and expert system technologies is necessary to capture and utilize the process planning logic. A system that maintains the dependability and clarity of variant systems, is capable of planning new parts, and improves itself through learning is needed by industry.展开更多
Since existing computer aided process planning (CAPP) systems have shortcomings such as difficultknowledge-acquisition, low intelligence level, weak optimization capability, etc.the application of artificial neuralnet...Since existing computer aided process planning (CAPP) systems have shortcomings such as difficultknowledge-acquisition, low intelligence level, weak optimization capability, etc.the application of artificial neuralnetworks (ANN) may significantly increase CAPP capabilities.Since ANN is self-learning, ANN has remarkable advantages in representing and acquiring of technical knowledge (especially that which is difficult to symbolize). In addition, since many procedures in CAPP are essentially optimization, ANN's combinatorial optimization capability canbe very useful.Both of these aspects of applying ANN to CAPP are described using an example which deals with process planning for machining of mechanical components.展开更多
Automatic fixture design is a key link in computer aided process planning. The uncertainty in the selection of fixture design schemes necessitates the use of the fuzzy comprehensive judgment method to automatically se...Automatic fixture design is a key link in computer aided process planning. The uncertainty in the selection of fixture design schemes necessitates the use of the fuzzy comprehensive judgment method to automatically select an optimal fixture design. This paper reports on the development of a computer aided fixture design system for non rotational parts using the fuzzy comprehensive judgment method running in an integrated process planning environment. Several typical non rotational parts with complicated configurations are used to demonstrate the automatic fixture design system.展开更多
文摘A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, agent oriented programming language, knowledge representation and reasoning strategy. The system can produce the technological file and technological quota, which can satisfy the production needs of factory.
文摘Process planning and scheduling are two major plann in g and control activities that consume significant part of the lead-time, theref ore all attempts are being made to reduce lead-time by automating them. Compute r Aided Process Planning (CAPP) is a step in this direction. Most of the existin g CAPP systems do not consider scheduling while generating a process plan. Sched uling is done separately after the process plan has been generated and therefore , it is possible that a process plan so generated is either not optimal or feasi ble from scheduling point of view. As process plans are generated without consid eration of job shop status, many problems arise within the manufacturing environ ment. Investigations have shown that 20%～30% of all process plans generated are not valid and have to be altered or suffer production delays when production sta rts. There is thus a major need for integration of scheduling with computer aide d process planning for generating more realistic process plans. In doing so, eff iciency of the manufacturing system as a whole is expected to improve. Decision support system performs many functions such as selection of machine too ls, cutting tools, sequencing of operations, determination of optimum cutting pa rameters and checking availability of machine tool before allocating any operati on to a machine tool. The process of transforming component data, process capabi lity and decision rules into computer readable format is still a major obstacle. This paper proposes architecture of a system, which integrates computer aided p rocess-planning system with scheduling using decision support system. A decisio n support system can be defined as " an interactive system that provides the use rs with easy access to decision models in order to support semi-structured or u nstructured decision making tasks".
文摘Computer aided inspection planning (CAIP) is one of the key quality assurance techniques in CIMS.CAIP generates inspection process data based on the product design requirements. Therefore, a unified product information model should be used to share product data with the CAD system. As a data exchange standard coveringthe complete product fife cycle, STEP could be used to integrate data transfer between CAD and CAIP. An inspection oriented mechanical product information model (IOMPIM ) is proposed in this paper. It includes form features,dimensional and tolerance information and uses EXPRESS for information modeling. The STEP pre-processor andpost-processor have been developed to transfer product model information between CAD and CAIP using the STEPneutral file. In preliminary system tests, product information for many complex parts was transferred through theCIMS environment with the CAIP system generating rational inspection processes. A coordinate measuring machinewas then used for quality inspection of the parts.
文摘THCAPP is a computer aided process planning system for non-rotational parts which runs in a CIMS (computer integrated manufacturing system ) environment at Tsinghua University. Its architecture is described in this paper. Then its main functions and key techniques, including part modeling, generative process planning and integration with CAD (computer aided design) and CAM (computer aided manufacturing) ale discussed in detail.
文摘Computer aided process planning (CAPP) aims at improving efficiency, quality, and productivity in a manufacturing concern through reducing lead times and costs by utilizing better manufacturing practices thus improving competitiveness in the market. CAPP attempts to capture the thoughts and methods of the experienced process planner. Variant systems are understandable, generative systems can plan new parts. Expert systems increase flexibility, fuzzy logic captures vague knowledge while neural networks learn. The combination of fuzzy, neural and expert system technologies is necessary to capture and utilize the process planning logic. A system that maintains the dependability and clarity of variant systems, is capable of planning new parts, and improves itself through learning is needed by industry.
文摘Since existing computer aided process planning (CAPP) systems have shortcomings such as difficultknowledge-acquisition, low intelligence level, weak optimization capability, etc.the application of artificial neuralnetworks (ANN) may significantly increase CAPP capabilities.Since ANN is self-learning, ANN has remarkable advantages in representing and acquiring of technical knowledge (especially that which is difficult to symbolize). In addition, since many procedures in CAPP are essentially optimization, ANN's combinatorial optimization capability canbe very useful.Both of these aspects of applying ANN to CAPP are described using an example which deals with process planning for machining of mechanical components.
文摘Automatic fixture design is a key link in computer aided process planning. The uncertainty in the selection of fixture design schemes necessitates the use of the fuzzy comprehensive judgment method to automatically select an optimal fixture design. This paper reports on the development of a computer aided fixture design system for non rotational parts using the fuzzy comprehensive judgment method running in an integrated process planning environment. Several typical non rotational parts with complicated configurations are used to demonstrate the automatic fixture design system.
