The Datum Flow Chain: A Systematic Approach to Assembly Design and Modeling

1998 ◽  
Author(s):  
R. Mantripragada ◽  
D. E. Whitney
Keyword(s):  
Design Process ◽  
Systematic Approach ◽  
Assembly Planning ◽  
Assembly Process ◽  
Top Down ◽  
Assembly Design ◽  
Key Characteristics ◽  
Assembly Sequences

Abstract In order to be able to lay out, analyze, outsource, assemble, and debug complex assemblies, we need ways to capture their fundamental structure in a top-down design process, including the designer’s strategy for kinematically constraining and locating the parts accurately with respect to each other. We describe a concept called the “Datum Flow Chain” to capture this logic. The DFC relates the datum logic explicitly to the product’s key characteristics, assembly sequences, and choice of mating features, and provides the information needed for tolerance analyses. Two types of assemblies are addressed: Type-1 where the assembly process puts parts together at their prefabricated mating features, and Type-2 where the assembly process can incorporate in-process adjustments to redistribute variation. Two types of assembly joints are defined: mates that pass dimensional constraint from part to part, and contacts that merely provide support. The scope of DFC in assembly planning is presented using several examples. Analysis tools to evaluate different DFCs and select the ones of interest are also presented.

Sequence-dependent cluster analysis of biomineralization peptides

2015 ◽  
Vol 70 (7-8) ◽  
pp. 191-195 ◽  
Author(s):  
Jose Isagani B. Janairo ◽  
Frumencio Co ◽  
Jose Santos Carandang ◽  
Divina M. Amalin
Keyword(s):  
Molecular Weight ◽  
Cluster Analysis ◽  
Classification System ◽  
Clustering Analysis ◽  
Systematic Approach ◽  
Molecular Weight Heterogeneity ◽  
Representative Samples

Abstract A reliable and statistically valid classification of biomineralization peptides is herein presented. 27 biomineralization peptides (BMPep) were randomly selected as representative samples to establish the classification system using k-means method. These biomineralization peptides were either discovered through isolation from various organisms or via phage display. Our findings show that there are two types of biomineralization peptides based on their length, molecular weight, heterogeneity, and aliphatic residues. Type-1 BMPeps are more commonly found and exhibit higher values for these significant clustering variables. In contrast are the type-2 BMPeps, which have lower values for these parameters and are less common. Through our clustering analysis, a more efficient and systematic approach in BMPep selection is possible since previous methods of BMPep classification are unreliable.

Research on Aircraft Assembly Sequence Planning Technology Based on Key Characteristics

2013 ◽  
Vol 328 ◽  
pp. 9-16 ◽  
Author(s):  
Zhan Lei Sun ◽  
Peng Fei Han ◽  
Gang Zhao
Keyword(s):  
Process Design ◽  
Assembly Sequence Planning ◽  
Assembly Process ◽  
Assembly Sequence ◽  
Assembly Quality ◽  
Constraint Matrix ◽  
Aircraft Assembly ◽  
Sequence Planning ◽  
Key Characteristics ◽  
Assembly Sequences

Assembly Sequence Planning (ASP) is an essential question for aircraft assembly process design. Modern aircraft assembly contains plenty of complex shape components, which have so many assembly features to ensure, this leads to a large number of feasible assembly sequences using traditional sequence planning algorithms; and it is hard to evaluate the contribution to assembly quality for every sequence. A methodology called Key Characteristics Based ASP is proposed in this paper, which can significantly reduce unavailable sequences and ensure key features for quality in assembly process designing compared with previous methods. The methodology focuses on the final assembly quality and considers it as Assembly Key Characteristics (AKCs) in the beginning of assembly process design. With tools such as AKCs decomposition, Datum Flow Chain, precedence constraint matrix, the methodology describes the main process for ASP. To verify the technologys effectiveness, this paper presents an application of the algorithm in an aircraft component assembly by an 863 program.

Process Planning Dynamic Model Based on HOOPN for Top-Down Collaborative Assembly Design

2008 ◽  
Vol 44-46 ◽  
pp. 215-224
Author(s):  
Yu Dong Yang ◽  
Zhi Hua Li ◽  
Shu Ting Zhang
Keyword(s):  
Dynamic Model ◽  
Design Process ◽  
Process Planning ◽  
Petri Net ◽  
Risk Level ◽  
Global Risk ◽  
Top Down ◽  
Assembly Design ◽  
Model Based ◽  
Collaborative Assembly

According to the characteristics of the design process of top-down collaborative assembly design, process planning dynamic model based on HOOPN (hierarchical object-oriented Petri-net) is constructed for top-down collaborative assembly design. The outside and inside task dependent relationships among the task groups include parallel, sequence and coupling are implemented. The definitions of attribute for each element and the activation rules are presented for Petri-net. The fuzzy overall evaluation model is applied for risk evaluation of design process, and the local and global risk level is determined. The whole process planning is adjusted and controlled based on special risk decision-making mechanism.

scholarly journals Decomposition-Based Assembly Synthesis for In-Process Dimensional Adjustability

2002 ◽  
Author(s):  
Byungwoo Lee ◽  
Kazuhiro Saitou
Keyword(s):  
Design Process ◽  
Early Stage ◽  
Product Configuration ◽  
Two Dimensional ◽  
Design Phase ◽  
Assembly Design ◽  
Component Design ◽  
Assembly Sequences ◽  
Simple Rules ◽  
Final Design

This paper presents a method of assembly synthesis focused on the in-process adjustability, where assembly synthesis is defined as the decomposition of the end product design prior to the detailed component design phase. Focusing on the effect of joint configurations on dimensional integrity of complex assemblies, the method recursively decomposes a product configuration and assigns joint configurations according to simple rules, in order to achieve a designed dimensional adjustability and non-forced fit. The rules employed during the decomposition process are drawn from the previous works of assembly design. An augmented AND/OR graph is utilized to represent a process of assembly synthesis with the corresponding assembly sequences, and the algorithm for generating the AND/OR graph is discussed. The method is applied to two dimensional skeletons of product designs at very early stage of the design process. The relation of the assembly synthesis to Datum Flow Chain (Mantripragada and Whitney, 1998) is discussed. It is also shown that each final design from the assembly synthesis defines its own Datum Flow Chain.

scholarly journals Decomposition-Based Assembly Synthesis for In-Process Dimensional Adjustability

2003 ◽  
Vol 125 (3) ◽  
pp. 464-473 ◽  
Author(s):  
Byungwoo Lee ◽  
Kazuhiro Saitou
Keyword(s):  
Design Process ◽  
Early Stage ◽  
Product Configuration ◽  
Two Dimensional ◽  
Design Phase ◽  
Assembly Design ◽  
Component Design ◽  
Assembly Sequences ◽  
Simple Rules ◽  
Final Design

This paper presents a method of assembly synthesis focused on the in-process adjustability, where assembly synthesis is defined as the decomposition of the end product design prior to the detailed component design phase. Focusing on the effect of joint configurations on dimensional integrity of complex assemblies, the method recursively decomposes a product configuration and assigns joint configurations according to simple rules, in order to achieve a designed dimensional adjustability and non-forced fit. The rules employed during the decomposition process are drawn from the previous works of assembly design. An augmented AND/OR graph is utilized to represent a process of assembly synthesis with the corresponding assembly sequences, and the algorithm for generating the AND/OR graph is discussed. The method is applied to two dimensional skeletons of products without moving parts at very early stage of the design process. The relation of the assembly synthesis to Datum Flow Chain [1] is discussed. It is also shown that each final design from the assembly synthesis defines its own Datum Flow Chain.

Mechanical systems and assemblies modeling using knowledge-intensive Petri nets formalisms

2001 ◽  
Vol 15 (2) ◽  
pp. 145-171 ◽  
Author(s):  
X.F. ZHA ◽  
H. DU
Keyword(s):  
Petri Nets ◽  
Design Process ◽  
Mechanical Systems ◽  
Object Oriented ◽  
Hybrid Design ◽  
Object Model ◽  
Top Down ◽  
Assembly Design ◽  
Knowledge Based ◽  
Knowledge Intensive

This paper presents a novel knowledge-based Petri net approach to mechanical systems and assemblies modeling within a design with objects environment. A new unified class of object-oriented knowledge Petri nets, which can incorporate a knowledge-based system with ordinary Petri nets, is defined and used for the unified representations of assembly design and modeling. The object knowledge Petri nets, as a graphical language and a new knowledge-based description scheme, can be used to express the qualitative and quantitative aspects of the assembly design and modeling process in an interactive and integrated way. The four-level hierarchy model is proposed and constructed in terms of function-behaviors, structures, geometries, and features. The function-behavior-structure description is built on more abstract concepts so that it can match well top-down design. The static and dynamic characteristics in the design of assembly can also be captured. With the help of fuzzy logic, the incomplete, imprecise knowledge and uncertainty in the design process can also be dealt with. Therefore, the hybrid design object model can incorporate product data model, top-down design process, and assembly process model using an object-oriented, knowledge-based, feature-based, parametric, and constraint-based modeling approach, and can provide a more accurate and more flexible representation. To verify and demonstrate the effective use of the proposed hybrid design object model, a prototype system has been developed. This research provides a knowledge-intensive framework for intelligent assembly design and modeling.

scholarly journals Development of a systematic approach to conversion of the ileoanal pouch into continent ileostomy

2021 ◽  
Author(s):  
K.-W. Ecker ◽  
C. Dinh ◽  
N. K. J. Ecker
Keyword(s):  
Systematic Approach ◽  
Practical Experience ◽  
Ileoanal Pouch ◽  
Jejunal Segment ◽  
Technical Details ◽  
Pouch Reconstruction ◽  
Type 3 ◽  
Technical Guidance

AbstractBased on practical experience, a systematic approach to conversion of ileal J-pouches into continent ileostomies is developed by defining three types of conversion surgery, each with two subtypes. Type 1 refers to conversion without pouch reconstruction, type 2 to partial pouch reconstruction, and type 3 to complete pouch reconstruction. The subdivisions (a and b) take into account whether the afferent loop of the former pelvic pouch (a) or a higher ileal/jejunal segment of the small intestine (b) is used in conversion and/or reconstruction. The six resulting surgical variants are shown in schematic illustrations with accompanying descriptions of technical details to provide the specialized surgeon with comprehensive technical guidance.

Combining Interactive Exploration and Optimization for Assembly Design

1996 ◽  
Author(s):  
Gerard Jounghyun Kim ◽  
Simon Szykman
Keyword(s):  
Simulated Annealing ◽  
Design Process ◽  
Design Space Exploration ◽  
Design Space ◽  
Space Exploration ◽  
Design History ◽  
Top Down ◽  
Design Exploration ◽  
Assembly Design ◽  
Design Alternatives

Abstract This paper presents an integrated framework for assembly design. The framework allows the designer to represent knowledge about the design process and constraints, as well as information about the artifact being designed, design history and rationale. Because the complexity of assembly design leads to extremely large design spaces, adequately supporting design space exploration is a key issue that must be addressed. This is achieved in part by allowing the designer to use both top-down and bottom-up approaches to assembly design. Exploration of the design space is further enabled by incorporating a simulated annealing-based optimization tool that allows the designer to rapidly complete partial designs, refine complete designs, and generate multiple design alternatives.

Dynamic Model of Process Planning for Top-Down Collaborative Assembly Design

2008 ◽  
Author(s):  
Youdong Yang ◽  
Shuting Zhang ◽  
Zhihua Li
Keyword(s):  
Decision Making ◽  
Dynamic Model ◽  
Design Process ◽  
Process Planning ◽  
Evaluation Model ◽  
Risk Level ◽  
Global Risk ◽  
Top Down ◽  
Assembly Design ◽  
Collaborative Assembly

The design process of top-down collaborative assembly design is high parallel. There are complex task relationships not only in a task group but also among different task groups, which we call them as inside and outside relationships. A dynamic model of process planning based on hierarchical object-oriented Petri-net (HOOPN) is constructed for top-down collaborative assembly design. The dynamic model represents the outside and inside task relationships including parallel, sequential and coupling relationships. Based on the dynamic model, the dynamic supervising, analysis and decision-making for the states of the design process are implemented. The fuzzy overall evaluation model (FOEM) is utilized for risk evaluation of the design process. The task execution is influenced by local and global risk level from FOEM. Finally, the whole process planning is adjusted and controlled dynamically by the special risk decision-making mechanism.

An Approach to Assembly Planning for Complex Products

1995 ◽  
Author(s):  
Igor A. Mukhanov
Keyword(s):  
Process Planning ◽  
Optimal Solution ◽  
Computation Time ◽  
Automatic Generation ◽  
Assembly Planning ◽  
Assembly Process ◽  
Assembly Process Planning ◽  
Complex Products ◽  
Assembly Sequences ◽  
The Given

Abstract We have developed a novel, efficient approach for assembly planning for complex products. This approach allows us to reflect the required information for assembly planning efficiently. Our approach has also been successfully used for the mathematical presentation of technological knowledge. An algorithm for the automatic generation of feasible assembly sequences for a given product has been developed. Within the assembly process-planning, feasible sequences are determined depending on the sequential assembly stages of the product. This approach permits the use of different criteria for the selection of a rational assembly plan, and it also allows for the influence of technological system elements (equipment, tools and periphery) on the given part of the product during a interval of the operation. We have successfully applied our approach for assembly process-planning of a complex product, a worm gear box. It has allowed us to reduce computation time greatly and to arrive at the optimal solution to real automated assembly.

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