Recognition of Freeform Surface Machining Features

2010 ◽  
Vol 10 (4) ◽  
Author(s):  
Jun Wang ◽  
Zhigang Wang ◽  
Weidong Zhu ◽  
Yingfeng Ji
Keyword(s):  
Critical Points ◽  
Computer Aided Design ◽  
Tool Path ◽  
Machining Process ◽  
Freeform Surface ◽  
Critical Surface ◽  
Machining Features ◽  
Computer Aided ◽  
Freeform Surface Machining ◽  
Machining Process Planning

This paper describes a method of machining feature recognition from a freeform surface based on the relationship between unique machining patches and critical points on a component’s surface. The method uses Morse theory to extract critical surface points by defining a scalar function on the freeform surface. Features are defined by region growing between the critical points using a tool path generation algorithm. Several examples demonstrate the efficiency of this approach. The recognized machining features can be directly utilized in a variety of downstream computer aided design/computer aided manufacturing (CAM) applications, such as the automated machining process planning.

An oriented feature extraction and recognition approach for concave-convex mixed interacting features in cast-then-machined parts

2018 ◽  
Vol 233 (4) ◽  
pp. 1269-1288 ◽  
Author(s):  
Haichao Wang ◽  
Jie Zhang ◽  
Xiaolong Zhang ◽  
Changwei Ren ◽  
Xiaoxi Wang ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Computer Aided Design ◽  
Feature Recognition ◽  
Freeform Surface ◽  
Layer By Layer ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Machined Parts ◽  
Aided Design ◽  
Interacting Features

Feature recognition is an important technology of computer-aided design/computer-aided engineering/computer-aided process planning/computer-aided manufacturing integration in cast-then-machined part manufacturing. Graph-based approach is one of the most popular feature recognition methods; however, it cannot still solve concave-convex mixed interacting feature recognition problem, which is a common problem in feature recognition of cast-then-machined parts. In this study, an oriented feature extraction and recognition approach is proposed for concave-convex mixed interacting features. The method first extracts predefined features directionally according to the rules generated from attributed adjacency graphs–based feature library and peels off them from part model layer by layer. Sub-features in an interacting feature are associated via hints and organized as a feature tree. The time cost is reduced to less than [Formula: see text] by eliminating subgraph isomorphism and matching operations. Oriented feature extraction and recognition approach recognizes non-freeform-surface features directionally regardless of the part structure. Hence, its application scope can be extended to multiple kinds of non-freeform-surface parts by customizing. Based on our findings, implementations on prismatic, plate, fork, axlebox, linkage, and cast-then-machined parts prove that the proposed approach is applicable on non-freeform-surface parts and effectively recognize concave-convex mixed interacting feature in various mechanical parts.

scholarly journals Engineering working operations based on parameters of product manufacturability using a computer-aided design algorithm

2022 ◽  
Vol 25 (6) ◽  
pp. 708-719
Author(s):  
D. A. Ishenin ◽  
A. S. Govorkov
Keyword(s):  
Computer Aided Design ◽  
Production Costs ◽  
Machining Process ◽  
Processing Route ◽  
Mechanical Processing ◽  
Design Algorithm ◽  
Industrial Data ◽  
Production Processes ◽  
Computer Aided ◽  
Aided Design

The study aimed to develop an algorithm for computer-aided design (CAD) of working operations. A processing route for machining components was developed based on the criteria of production manufacturability, industrial data and a digital model of the product. The process of machining a workpiece was analysed using a method of theoretical separation. The machining process of a frame workpiece was used as a model. The identified formal parameters formed a basis for developing a CAD algorithm and a model of manufacturing route associated with the mechanical processing of a work-piece applying a condition-action rule, as well as mathematical logic. The research afforded a scheme for selecting process operations, given the manufacturability parameters of a product design. The concept of CAD algorithm was developed to design a production process of engineering products with given manufacturability parameters, including industrial data. The principle of forming a route and selecting a machining process was proposed. Several criteria of production manufacturability (labour intensity, consumption of materials, production costs) were selected to evaluate mechanical processing. A CAD algorithm for designing technological operations considering the parameters of manufacturability was developed. The algorithm was tested by manufacturing a frame workpiece. The developed algorithm can be used for reducing labour costs and development time, at the same time as improving the quality of production processes. The formalisation of process design is a crucial stage in digitalisation and automation of all production processes.

POWERTRAIN MACHINING FEATURE IDENTIFICATION

2004 ◽  
Vol 03 (01) ◽  
pp. 103-110 ◽  
Author(s):  
SANGCHUL PARK
Keyword(s):  
Feature Recognition ◽  
Geometric Algorithms ◽  
Machining Process ◽  
Feature Identification ◽  
Machining Features ◽  
Efficient Procedure ◽  
Machining Feature ◽  
Intuitive Idea ◽  
Machining Process Planning ◽  
Part Model

Presented in this paper is a procedure to identify machining features of powertrain components. Machining feature recognition is one of the most important steps for machining process planning. In the case of powertrain components, the first step is to compare a machined model (finished part model) and the corresponding rough part model to identify the volume which should be removed from the rough part model. In regard to the comparison, the most intuitive idea is to use a 3D BOOLEAN operation. Although this approach looks fine, it might not take advantage of the inherent attributes of powertrain component machining. This paper focuses on two important attributes of powertrain machining: (1) a machined model and the corresponding rough part model are very similar and have many identical faces and (2) a rough part model always contains the machined model. Based on these two attributes, we develop an efficient procedure for identifying powertrain machining features. Since the proposed procedure employs well-known 2D geometric algorithms instead of 3D BOOLEAN operations, it is very efficient and robust.

scholarly journals Direct Digital Subtractive Manufacturing of a Functional Assembly Using Voxel-Based Models

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Roby Lynn ◽  
Mahmoud Dinar ◽  
Nuodi Huang ◽  
James Collins ◽  
Jing Yu ◽  
...  
Keyword(s):  
Process Planning ◽  
Computer Aided Design ◽  
Complex Geometry ◽  
Geometric Constraints ◽  
Machining Process ◽  
Layer By Layer ◽  
User Input ◽  
Computer Aided ◽  
Subtractive Manufacturing ◽  
The Creation

Direct digital manufacturing (DDM) is the creation of a physical part directly from a computer-aided design (CAD) model with minimal process planning and is typically applied to additive manufacturing (AM) processes to fabricate complex geometry. AM is preferred for DDM because of its minimal user input requirements; as a result, users can focus on exploiting other advantages of AM, such as the creation of intricate mechanisms that require no assembly after fabrication. Such assembly free mechanisms can be created using DDM during a single build process. In contrast, subtractive manufacturing (SM) enables the creation of higher strength parts that do not suffer from the material anisotropy inherent in AM. However, process planning for SM is more difficult than it is for AM due to geometric constraints imposed by the machining process; thus, the application of SM to the fabrication of assembly free mechanisms is challenging. This research describes a voxel-based computer-aided manufacturing (CAM) system that enables direct digital subtractive manufacturing (DDSM) of an assembly free mechanism. Process planning for SM involves voxel-by-voxel removal of material in the same way that an AM process consists of layer-by-layer addition of material. The voxelized CAM system minimizes user input by automatically generating toolpaths based on an analysis of accessible material to remove for a certain clearance in the mechanism's assembled state. The DDSM process is validated and compared to AM using case studies of the manufacture of two assembly free ball-in-socket mechanisms.

Computer-Aided Manufacturing (CAM) Software Development for Laser Machining

2013 ◽  
Author(s):  
Abdolreza Bayesteh ◽  
Farid Ahmad ◽  
Martin B. G. Jun
Keyword(s):  
Laser Ablation ◽  
Tool Path ◽  
Laser Energy ◽  
Machining Process ◽  
Work Piece ◽  
Software System ◽  
Computer Aided Manufacturing ◽  
Computer Aided ◽  
Tool Trajectory ◽  
Cam Software

A novel computer-aided manufacturing (CAM) software system is proposed for laser ablation machining process. The algorithms and prototype software system is designed to offer efficient optimization of tool path for controlled delivery of laser energy into work-piece. The software simplifies part program creation and maintains constant velocity of the sample stage for each segment of a complex tool trajectory. These features enable efficient deposition of laser energy into the work piece and therefore, reduction in heat-affected zone is expected in laser ablation based micromachining. The reported software provides fast modification of tool path, automatic and efficient sequencing of path elements in a complicated tool trajectory, location of reference point and automatic fixing of geometrical errors in imported drawing exchange files (DXF) or DWG format files.

scholarly journals T-Spline Surface Toolpath Generation Using Watershed-Based Feature Recognition

2020 ◽  
Vol 10 (19) ◽  
pp. 6790
Author(s):  
Yazui Liu ◽  
Gang Zhao ◽  
Pengfei Han
Keyword(s):  
Feature Recognition ◽  
Machining Process ◽  
Freeform Surface ◽  
Local Refinement ◽  
Surface Machining ◽  
Spline Surface ◽  
Toolpath Generation ◽  
Comparison Results ◽  
Bounding Boxes ◽  
Freeform Surface Machining

The freeform surface is treated as a single machining region for most traditional toolpath generation algorithms. However, due to the complexity of a freeform surface, it is impossible to produce a high-quality surface using one unique machining process. Hence, region-based methods are widely investigated for freeform surface machining to achieve an optimized toolpath. The Non-Uniform Rational B-spline Surface (NURBS) represented freeform surface is not suitable for region-based toolpath generation because of the surface gaps caused by NURBS trimming and merging operations. To solve the limitation of the NURBS, T-spline is proposed with the advantages of being gap-free, having less control points, and local refinement, which is an ideal tool for region-based toolpath generation. Thus, T-spline is introduced to represent a freeform surface for its toolpath generation in the paper. A region-based toolpath generation method for the T-spline surface is proposed based on watershed technology. Firstly, watershed-based feature recognition is presented to divide the T-spline surface into a set of sub-regions. Secondly, the concept of a PolyBoundingBox that consists of a set of minimum bounding boxes is proposed to describe the sub-regions, and Manufacturing-Suitable Regions are constructed with the help of T-spline local refinement and the PolyBoundingBox. In the end, an optimized multi-rectangles toolpath generation algorithm is applied for sub-regions. The proposed method is tested using three synthetic T-spline surfaces, and the comparison results show the advantage in toolpath length and toolpath reversing number.

Morphological Offset Computing for Contour Pocketing

2006 ◽  
Vol 129 (2) ◽  
pp. 400-406 ◽  
Author(s):  
R. Molina-Carmona ◽  
A. Jimeno ◽  
R. Rizo-Aldeguer
Keyword(s):  
Computer Aided Design ◽  
Tool Path ◽  
Free Form ◽  
Computer Aided Manufacturing ◽  
Theoretical Formulation ◽  
Topological System ◽  
Computer Aided ◽  
Cad Cam ◽  
Tool Shape ◽  
Aided Design

Background. Tool path generation problem is one of the most complexes in computer aided manufacturing. Although some efficient algorithms have been developed to solve it, their technological dependency makes them efficient in only a limited number of cases. Method of Approach. Our aim is to propose a model that will set apart the geometrical issues involved in the manufacturing process from the purely technology-dependent physical issues by means of a topological system. This system applies methods and concepts used in mathematical morphology paradigms. Thus, we will obtain a geometrical abstraction which will not only provide solutions to typically complex problems but also the possibility of applying these solutions to any machining environment regardless of the technology. Presented in the paper is a method for offsetting any kind of curve. Specifically, we use parametric cubic curves, which is one of the most general and popular models in computer aided design (CAD)/computer aided manufacturing (CAM) applications. Results. The resulting method avoids any constraint in object or tool shape and obtains valid and optimal trajectories, with a low temporal cost of O(n∙m), which is corroborated by the experiments. It also avoids some precision errors that are present in the most popular commercial CAD/CAM libraries. Conclusions. The use of morphology as the base of the formulation avoids self-intersections and discontinuities and allows the system to machine free-form shapes using any tool without constraints. Most numerical and geometrical problems are also avoided. Obtaining a practical algorithm from the theoretical formulation is straightforward. The resulting procedure is simple and efficient.

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