A Graph-Based Approach for Capturing the Capability Envelope of a Machining Process

2003 ◽  
Vol 125 (2) ◽  
pp. 272-288 ◽  
Author(s):  
Zhengdong Huang ◽  
Derek Yip-Hoi ◽  
Ji Zhou
Keyword(s):  
Process Planning ◽  
Machining Process ◽  
Machining Operations

In this paper, we present a method to determine the capability envelope of a machining process which consists of a sequence of parameterized machining operations. First, operations as well as workpiece in a machining process are represented using a Parametric Feature Relational Graph (P-FRG). Second, the workpiece P-FRG within a process is updated step-by-step by mixing with operation P-FRGs as the operations in the process are successively applied to it. Since alternative setups may exist for an operation, a tree of workpiece P-FRGs can be generated for a process. All the P-FRGs at the leaf nodes of the tree together form the capability envelope of the machining process, that is, the envelope of the parts that can be produced using the process from a given initial workpiece. The parameter mappings, from the parameters of a machining process to the parameters of a part P-FRG in the capability envelope, are also given in this paper. The capability envelope can be applied to the integration of part design and process planning.

Geodesic Distance Field-based Process Planning for Five-Axis Machining of Complicated Parts

2020 ◽  
pp. 1-27
Author(s):  
Dong He ◽  
Yamin Li ◽  
Zhaoyu Li ◽  
Kai Tang
Keyword(s):  
Process Planning ◽  
Geodesic Distance ◽  
Machining Process ◽  
Rough Machining ◽  
Distance Field ◽  
Tool Paths ◽  
Solid Part ◽  
Level Method ◽  
Machining Operations ◽  
Five Axis

Abstract A critical task in multi-pass process planning for five-axis machining of complicated parts is to determine the intermediate surfaces for rough machining. Traditionally, the intermediate surfaces are simply parallel Z-level planes, and the machining is of the simplest three-axis type. However, for complicated parts, this so-called Z-level method lacks flexibility and causes isolated islands on layers, which require extraneous air movements by the tool. Moreover, the in-process workpiece machined according to the Z-level method suffers from the staircase effect, which often induces unstable dynamic problems on the tool-spindle system. In this paper, we propose a new method of planning a five-axis machining process for a complicated freeform solid part. In our method, the intermediate surfaces are no longer planar but curved, and they are intrinsically influenced by the convex hull of the part. The powerful algebraic tool of geodesic distance field is utilized to generate the desired intermediate surfaces, for which collision-free five-axis machining tool paths are then planned. In addition, we propose a novel idea of alternating between the roughing and finishing machining operations, which helps improve the stiffness of the in-process workpiece. Ample physical cutting experiments are performed, and the experimental results convincingly confirm the advantages of our method.

Späne- und Stauberfassung bei der CFK-Zerspanung*/Extraction of chips and dust in machining operations of CFRP. Investigation on CFRP dry machining in industrial applications

2018 ◽  
Vol 108 (06) ◽  
pp. 473-478
Author(s):  
A. Gebhardt ◽  
M. Schneider
Keyword(s):  
Industrial Applications ◽  
Machining Process ◽  
Dry Machining ◽  
Machining Processes ◽  
Dry Cutting ◽  
Clamping System ◽  
Cutting Processes ◽  
Machining Operations

Bauteile aus CFK (kohlenstofffaserverstärkte Kunststoffe) werden meist spanend endbearbeitet. Diese Bearbeitung kann unter Überflutung durch KSS (Kühlschmierstoffe) oder trocken stattfinden. Die hier vorgestellte Studie zeigt für die Trockenzerspanung, wie die notwendige Erfassung von Stäuben und Spänen stattfindet, welche Technologien eingesetzt werden und wie eine Maschinen- und Bauteilreinigung aussieht.   A machining process is mostly used as a last step in the production of workpieces made of CFRP. In this machining process lubricants may be used or dry cutting processes are applicated. The here presented study shows for dry machining processes, which technologies are used for the dust and chip extraction. Furthermore, the techniques for the cleaning of the machine, the clamping system and workpiece are presented.

An Integrated Process Planning System Architecture for Machining and On-Machine Inspection

2008 ◽  
Author(s):  
Yaoyao F. Zhao ◽  
Xun W. Xu ◽  
Sheng Q. Xie ◽  
Tom R. Kramer ◽  
Fred M. Proctor ◽  
...  
Keyword(s):  
Real Time ◽  
Process Planning ◽  
System Architecture ◽  
Data Model ◽  
Machining Process ◽  
Planning System ◽  
Integrated Process ◽  
Process Planning System ◽  
Inspection Process ◽  
Manufacturing Chain

Inspection is an essential part of the entire manufacturing chain providing measurement feedback to the process planning system. Fully automated machining requires automatic inspection process planning and real-time inspection results feedback. As inspection process planning is still based on G&M codes containing low-level information or vendor-specific bespoke routines, inspection process planning is mostly isolated from machining process planning. With the development of new data model standards STEP and STEP-NC providing high-level product information for the entire manufacturing chain, it is achievable to combine machining and inspection process planning to generate optimal machining and inspection sequences with real-time measurement results feedback. This paper introduces an integrated process planning system architecture for combined machining and inspection. In order to provide real-time inspection feedback, On-Machine Inspection (OMI) is chosen to carry out inspection operations. Implementation of the proposed architecture has been partially carried out with a newly developed data model and interpreter software. A case study was carried out to test the feasibility of the proposed architecture.

Generating STEP-NC Files for a Circuit Board Milling System

2012 ◽  
Vol 430-432 ◽  
pp. 1686-1691
Author(s):  
Ke Wang ◽  
Cheng Rui Zhang ◽  
Ri Liang Liu ◽  
Xiang Zhi Zhang
Keyword(s):  
Process Planning ◽  
Manufacturing Industry ◽  
Circuit Board ◽  
Machining Features ◽  
Tool Paths ◽  
Face Contour ◽  
Modern Manufacturing ◽  
Machining Operations ◽  
Parallel Strategy

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.

Overview of a Distributed Process Planning Approach Targeting Manufacturing Uncertainty

2006 ◽  
Author(s):  
Lihui Wang ◽  
Ningxu Cai ◽  
Hsin-Yung Feng
Keyword(s):  
Process Planning ◽  
Job Shop ◽  
Layer Structure ◽  
Dynamic Decision Making ◽  
Machining Process ◽  
Operation Planning ◽  
Planning Approach ◽  
Job Shop Operations ◽  
Function Blocks ◽  
Distributed Process

This paper presents an overview of our DPP (distributed process planning) approach, covering DPP concept, generic machining process sequencing using enriched machining features, process plan encapsulation in function blocks, and process monitoring enabled by the function blocks. A two-layer structure of Supervisory Planning and Operation Planning is proposed in DPP to separate generic data from machine-specific ones. The supervisory planning is only performed once, in advance, at shop level, whereas the operation planning is carried out at runtime at machine level. This dynamic decision-making is facilitated by a set of resource-driven algorithms embedded in the function blocks. The internal structures of typical function blocks are also introduced in the paper. The DPP approach and algorithms are further verified through a case study before drawing conclusions. It is expected that the new approach can largely enhance the dynamism of fluctuating job shop operations.

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