Feature reasoning for sheet metal components

Nnaji, Bartholomew O.; Kang, Tzong-Shyan; Yeh, Shuchieh; Chen, Jang-Ping

doi:10.1080/00207549108948055

Cited by 41 publications

(12 citation statements)

References 1 publication

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“…The edges associated with these portions of the contour crystallize as a feature. This provides a quantitative de® nition of a feature which is consistent with the de® nition by Nnaji et al (1991).…”

Section: O Setting and Contour Featuresmentioning

confidence: 80%

Profile offsetting for feature extraction and feature tool mapping in sheet metal

Devarajan¹,

Kamran²,

Nnaji³

1997

International Journal of Production Research

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It is widely accepted that automatic process planning is the key solution to bridging the gap between design and manufacturing. In order to realize this, it is important that the CAD system should not only allow the designer to work in terms of features which relate to manufacturing operations but also be able to extract features and recognize them. Extraction of features internal to the contour of the sheet metal involves identifying groups that are connected to members within itself but not connected to any other group. However the same rationale cannot be adopted for features on the contour due to their lack of connectivity. This paper presents a new approach towards extracting contour features by generating the o set of the contour. It is important that once the features have been extracted and recognized, appropriate tools for creating the feature be identi® ed. This paper proposes a tool mapping algorithm based on the medial axis transformation (MAT). Since stamping is assumed to be the method of manufacturing, feature-tool mapping involves identifying the punch which can stamp the feature.

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Section: O Setting and Contour Featuresmentioning

confidence: 80%

Profile offsetting for feature extraction and feature tool mapping in sheet metal

Devarajan¹,

Kamran²,

Nnaji³

1997

International Journal of Production Research

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“…Tolerances are not addressed at this stage. Automation of manufacturability evaluation requires features to be recognized from the CAD model by reasoning (Van Houten et al 1989, Nnaji et al 1991, Tisza 1995, Wang and Sturges 1996, Devarajan et al 1997. The feature reasoner recognizes sheet metal features and extracts feature and part related information and makes it available to the design evaluator and the process planner simultaneously for further use (Ramana and Rao 2004a, b).…”

Section: Automated Manufacturability Evaluation Systemmentioning

confidence: 99%

Automated manufacturability evaluation system for sheet metal components in mass production

Ramana¹,

Rao²

2005

International Journal of Production Research

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Automated manufacturability evaluation of a given design is a key requirement in realizing complete integration of design and process planning. It would still be better to control the designing process itself with manufacturability information. The purpose of such an evaluation is to assist designers in their effort to come up with manufacturable parts economizing in terms of cost and time, without compromising on quality and functional requirements. The present work deals with one such system developed for manufacturability evaluation of sheet metal components. Unlike most of the work done in the sheet metal area in the past, which concentrates on specific domain or phase of manufacturability evaluation, the present work is more comprehensive combining characteristics of all the existing methods and phases of manufacturability evaluation. The prime components of the present system are design evaluation and process plan generation. Design evaluator and process planner use different types of data and knowledge to identify design and process planning violations which are overcome by suggesting design changes. A process planner also uses manufacturing resource and process information to arrive at manufacturable parts by generating feasible process plans. Results of manufacturability evaluation are presented for typical sheet metal parts to be produced by bending and shearing (blanking and piercing) processes.

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“…A n umber of systems have been developed to automate various process planning functions for sheet metal parts 5,16,18,22]. Many of these system attempt to handle a wide variety of sheet metal processes and attempt to sequence various operations based on high level interactions among them.…”

Section: Sheet Metal Bending Operation Planningmentioning

confidence: 99%

Sheet metal bending operation planning: Using virtual node generation to improve search efficiency

Gupta

1999

Journal of Manufacturing Systems

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. Sheet metal bending operation planning: Using virtual node generation to improve search efficiency. Journal of Manufacturing Systems, 18(2):127-139, 1999. Readers are encouraged to get the official version from the journal's web site or by contacting Dr. S.K. Gupta (skgupta@umd.edu). manufacturing operations planning, state-space search, sheet-metal bending, and setup planning. Sheet Metal Bending AbstractA large numberofmanufacturing operation planning problems can beformulated as state-space search problems. In case of sheet-metal bending operation planning, processing a search node involves extensive geometric reasoning. Such computationintensive node-processing limits the numberofsearch nodes that can be expanded in a reasonable amount of time, making it di cult to solve real-life operation planning problems.In this paper, we describe a scheme to speed up operation planning by virtual generation of state-space nodes. In this scheme, we eliminate unnecessary computation at the time of node generation by extracting the required information from already generated nodes. Although generation of two di erent search nodes rarely involves identical computation steps, there is considerable overlap in node generation steps. We h a ve divided the node generation step into a number of computation subproblems. When we need to generate a new node, we rst try to see if any of the node generation subproblems have been solved for any of the already generated nodes. If any subproblem has already beensolved for some other node, then we use the solution of that subproblem to save computation time. In such cases, we do not perform node generation computation steps, and therefore we c a l l s u c h node generation virtual.The scheme presented in this paper increases the node generation capability and allows us to consider many more search nodes. The ability to consider more search nodes helps us in solving more complex problems and nding better operation plans.

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Feature reasoning for sheet metal components

Cited by 41 publications

References 1 publication

Profile offsetting for feature extraction and feature tool mapping in sheet metal

Profile offsetting for feature extraction and feature tool mapping in sheet metal

Automated manufacturability evaluation system for sheet metal components in mass production

Sheet metal bending operation planning: Using virtual node generation to improve search efficiency

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