外文翻譯---基于知識(shí)工程的汽車覆蓋件沖壓路線分析

1、KBE-based stamping process paths generated for automobile panels Jinqiao Zheng . Yilin Wang . Zhigang LiAbstract: As automobile body panels are one kind of sheet metal part with groups of free form surfaces, the proces

2、s planning is more complicated than common sheet metal stamping to implode effectively and practically. Based on KBE, new frameworks have been presented as intelligent master model at the system level and as procedure mo

3、del at the activity level. In accordance with these frameworks, an intelligent CAPP system has been specifically developed. Based on feature technology, features have been extracted and represented by the object-oriented

4、 method. Stamping features and their parameters have been defined and extracted based on feature technology and stamping process rules. The whole product knowledge has been represented by frames which directly map to obj

5、ects (or features) in the object-oriented sense. Relevant appropriate operations features have been assigned to stamping features of a product based on feature-operation criteria, parameters of the stamping feature and t

6、heir correlativity. This assignment is a decision-making activity using a set of rules with a decision-making tree and model-based reasoning methods. With knowledge between operations, such as operations order constraint

7、 (do-after) and operations combination constraint, process paths have been improved based on relevant intelligent reasoning methods. Based on the relationships (preferred-to) between processes and machines/dies, the stru

8、cture of die and machine for each process can be identified, since the process route has been determined. In this stamping process planning, the procedure and information have been controlled by a process control structu

9、re that is associative and integrated. 1 IntroductionRecently, research on the computer-aided process planning (CAPP) system for sheet metal has been widely reported. Park et al. [1] constructed an automated process plan

10、ning system for ax symmetric deep drawing products. Tessa [2] and Kang and Park [3] presented a group technology and modularity to construct a CAPP system for process sequence design in an expert system for non-ax symmet

11、ric deep drawing products with elliptical shape. Gao et al. [4] developed an advanced software toolset used for the automation of sheet metal fabrication planning for aircraft components. Zussman and Horsch [5] proposed

12、a motion planning approach for robot-assisted multiple-bent parts based on C-space and a potential field. Wang and Bourne [6] proposed an automatic process planning system with the features well investigated and the prod

13、uction plans researched with near-minimum manufacturing costs. De Vin et al. [7 , 8] developed a sheet-metal CAPP system called PART-S, which integrates cutting, nesting, bending and welding processes for bending sequenc

14、es. Streppel et al. [9] showed the ambiguity of conventional tolerances and presented a method which replaces conventional tolerances with geometrical tolerances for process planning in small batch sheet metal part manuf

15、acturing. Amoral et al. [10] proposed a method which generated feasible bending sequences of a sheet metal part handled by a robot, and discussed the determination of the best grasping positions and repositions. Aomura a

16、nd Koguchi [11] pro- posed a method to generate bending sequences of a sheet metal part handled by a robot. Liao and Wang [12] proposed an evolutionary path-planning approach for robot-assisted handling matching of valid

17、 combinations of components. – Engineering knowledge – this enables manufacturing and other considerations to be built into the product design. When a candidate application area requires a high degree of integration of t

18、he above elements, KBE is likely to be the best method for its integration. KBE is sometimes termed rule-based engineering, as within the discipline, knowledge is often represented by rules. These may be mathematical for

19、mulae or conditional statements, and although simple in concept, they may then be combined to form complex and powerful expressions. KBE systems, on the other hand, are usually provided with specialized geometrical capab

20、ilities, with the ability to embed engineering knowledge within a product model. The following examples of typical KBE applications demonstrate some of the considerable benefits to be gained from its use.1) Lotus enginee

21、ring. This used the integrated car engineer (ICE) system in the design of the Lotus Elise. ICE consists of a vehicle layout system, and modules to support the design of suspension, engines, power-train, wheel envelope an

22、d wipers [ 17].2) The Boeing Commercial Airplane Group. This uses KBE as a tool to capture airplane knowledge to reduce the resources required for producing a design [18].3) Jaguar cars. The company’s KBE group devised a

23、 system that reduced the time taken to design an inner bonnet from 8 weeks to 20 min [19].2.2 Problem to solve in a CAPP system based on KBEA stamping CAPP system should deal with all knowledge including geometry, non-ge

24、ometry, engineers experience, rules and criteria, results of tests and numerical simulation, or even successful cases, because of the complexity of automobile body panels. The knowledge is involved in diverse fields, suc

25、h as metal forming technology, metal forming mechanics, modern design methodology, numerical simulation technology, and artificial intelligence. Accordingly, the CAPP system has to solve the problems with expression and

26、application of all knowledge, and integration of all multidisciplinary design. A CAPP system is essentially a set of instructions and guidelines on how to perform a complex procedure. It details the individual sub-tasks,

27、 how they should be carried out, in what order, and how the work should be documented. Furthermore, as system requirements change, new solutions tend to evolve from existing ones, so computer applications and their desce

28、ndants can outlive the personnel involved in their initial development. All in all, a stamping CAPP system for automobile panels based on KBE should readily solve the following problems:(1) Representations for all knowle

29、dge.(2) Reasoning based on all this knowledge.(3) Appropriate operation features acquired from stamping features and process rules incorporated with form- ability analysis.(4) Process routes based on process sequencing a

30、nd process combination knowledge.(5) The control or management of process procedures for rapid response to all changes.3 Framework of a CAPP system3.1 The integrated master model for a CAPP systemTo solve all correspondi