Feature Based Shape Similarity Measurement for Retrieval of Mechanical Parts

2001 ◽  
Vol 1 (3) ◽  
pp. 245-256 ◽  
Author(s):  
Madhumati Ramesh ◽  
Derek Yip-Hoi ◽  
Debasish Dutta

Exploiting shape similarities amongst parts for applications such as variant process planning is well known in the manufacturing industry. This particular application requires a mechanism for retrieval of similar parts from a part database which in turn requires a method for shape similarity measurement. In this paper, such a method is presented. First, the part is decomposed into simpler shapes resembling machining features. The decomposition method makes use of primitives to generate the shapes directly unlike previous methods in which the shapes are produced by combining minimal cells. Next, part characteristics that capture the spatial and dimensional relationships amongst features are used to measure the similarity. These characteristics are relevant to machining and they complement the characteristics such as feature type and feature intersections that are used by the previous shape comparison techniques. Implementation and examples are also included.

Author(s):  
Madhumati M. Ramesh ◽  
Derek Yip-Hoi ◽  
Debasish Dutta

Abstract Many applications such as computer aided process planning require an interpretation of the complex geometry of a mechanical part in terms of simpler local shapes such as machining features. Decomposition of non-polyhedral parts is difficult as compared to that of polyhedrons, but mechanical parts are seldom polyhedral. A decomposition method that makes use of primitives for planar and cylindrical faces of parts is presented in this paper. A semi-automatic method for mapping the resulting shapes to library-features is also presented. The proposed method for decomposition and mapping is simple, intuitive and easy to implement using standard geometric and solid modeling operators.


2012 ◽  
Vol 430-432 ◽  
pp. 1686-1691
Author(s):  
Ke Wang ◽  
Cheng Rui Zhang ◽  
Ri Liang Liu ◽  
Xiang Zhi Zhang

Since G-codes have been proved limiting the modern manufacturing industry, ISO14649 was put forward. This paper presents a solution to generate ISO14649 files for circuit board milling. The process planning is given, and all the processes needed are contained in the ISO14649 file. Features and machining operations are identified for each process, such as the closed pocket having a “General_closed_profile” attribute and bosses, round holes, slots, the planar face, contour parallel strategy, contour bidirectional strategy and etc. The scenario of one feature with multi tools are put forward to promote the milling efficiency and an entity “Combined_Machining_workingsteps” is proposed. Besides, some other extensions are made, such as entities for representing circuit geometries in machining features. Algorithms for tool paths generation are demonstrated for contour parallel milling and bidirectional milling, where a new algorithm based on pixels is used. The new algorithm can be used in other functions such as detecting uncut regions.


Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 61
Author(s):  
Trung Kien Nguyen ◽  
Lan Xuan Phung ◽  
Ngoc-Tam Bui

In the modern manufacturing industry, the role of computer-aided process planning (CAPP) is becoming increasingly crucial. Through the application of new technologies, experience, and intelligence, CAPP is contributing to the automation of manufacturing processes. In this article, the integration of a proposed CAPP system that is named as BKCAPP and G-code generation module provides a completed CAD–CAPP–CNC system that does not involve any manual processing in the CAM modules. The BKCAPP system is capable of automatically performing machining feature and operation recognition processes from design features in three-dimensional (3D) solid models, incorporating technical requirements such as the surface roughness, geometric dimensions, and tolerance in order to provide process planning for machining processes, including information on the machine tools, cutting tools, machining conditions, and operation sequences. G-code programs based on macro programming are automatically generated by the G-code generation module on the basis of the basic information for the machining features, such as the contour shape, basic dimensions, and cutting information obtained from BKCAPP. The G-code generation module can be applied to standard machining features, such as faces, pockets, bosses, slots, holes, and contours. This novel integration approach produces a practical CAPP method enabling end users to generate operation consequences and G-code files and to customize specific cutting tools and machine tool data. In this paper, a machining part consisting of basic machining features was used in order to describe the method and verify its implementation.


Author(s):  
JungHyun Han ◽  
Aristides A. G. Requicha

Abstract Process planning for machined parts typically requires that a part be described through machining features such as holes, slots and pockets. This paper presents a novel feature finder, which automatically generates a part interpretation in terms of machining features, by utilizing information from a variety of sources such as nominal geometry, tolerances and attributes, and design features. The feature finder strives to produce a desirable interpretation of the part as quickly as possible. If this interpretation is judged unacceptable by a process planner, alternatives can be generated on demand. The feature finder uses a hint-based approach, and combines artificial intelligence techniques, such as blackboard architecture and uncertain reasoning, with the geometric completion procedures first introduced in the OOFF system previously developed at USC.


Author(s):  
Xu Zhang ◽  
Chao Liang ◽  
Tiedong Si ◽  
Ding Ding

In process planning of machined part, machining feature recognition and representation, feature-based generative process planning, and the process intermediate model generation are the key issues. While many research results have been achieved in recent years, the complete modeling of machining features, process operations, and the 3D models in process planning are still need further research to make the techniques to be applied in practical CAPP systems. In this paper, a machining feature definition and classification method is proposed for the purpose of process planning based on 3D model. Machining features are defined as the surfaces formed by a serious of machining operation. The classification scheme of machining features is proposed for the purpose of feature recognition, feature-based machining operations reasoning, and knowledge representation. Recognized from B-Rep representation of design model, machining features are represented by adjacent graph and organized by feature relations. The machining process plan is modeled as operations and steps, which is the combination and sequencing of machining feature’s process steps. The process intermediate models (PIM) are important for process documentation, analysis and NC programming. An automatic PIM generation approach is proposed using local operations directly on B-Rep model. The proposed data structure and algorithm is adopted in the development of CAPP tool on solid modeler ACIS/HOOPS.


2017 ◽  
Vol 11 (2) ◽  
pp. 242-250 ◽  
Author(s):  
Kenta Koremura ◽  
◽  
Yuki Inoue ◽  
Keiichi Nakamoto

In the manufacturing industry, there is an urgent need to shorten the manufacturing lead time of products. Therefore, optimizing process planning is essential to realize high efficiency machining. In this study, in order to develop a computer aided process planning (CAPP) system using previously proposed machining features, a prediction method for some process evaluation indices is proposed. Many candidates for the machining process exist, depending on the recognized machining features in a previous study. Therefore, by using these indices, operators can select a suitable process from among these candidates according to their ideas. Case studies of process planning are conducted to confirm that the operator’s strategy affects the selection of the machining process candidates. From the case study results, it is found that the proposed process evaluation indices have potential use in determining the machining process utilized, and are suitable for a flexible CAPP system of multi-tasking machine tools.


2021 ◽  
Author(s):  
Amjad B. Abdulghafour ◽  
Salman H. Omran ◽  
Sadiq H. Al-Kabi ◽  
Abdulsattar A. Abdullah ◽  
Osamah H. Hussein

2014 ◽  
Vol 598 ◽  
pp. 591-594 ◽  
Author(s):  
Li Yan Zhang

ISO 14649, known as STEP-NC, is new model of data transfer between CAD/CAM systems and CNC machines. In this paper, the modeling based on machining feature is proposed. The machining feature comes from the manufacturing process considering the restriction of machining technology and machining resource. Then the framework for computer aided process planning is presented, where the algorithms of operation planning is studied. The practical example has been provided and results indicate that machining feature based model can integrate with CAPP and STEP-NC seamlessly.


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