An Introduction to the Designers’ Sandpit

2000 ◽  
Author(s):  
Susan J. Tate ◽  
Graham E. M. Jared ◽  
Nathaniel J. Brown ◽  
Kenneth G. Swift
Keyword(s):  
Geometric Reasoning ◽  
Assembly Planning ◽  
General Context ◽  
Research Subject ◽  
Design Environment ◽  
Detailed Design ◽  
Functional Modelling ◽  
Challenging Research ◽  
Functional Representations ◽  
Modelling Approach

Abstract This paper introduces the notion of the Designers’ Sandpit. It presents the proposed user interface, a preliminary view of a Proactive DFA methodology and the geometric reasoning functionality required to support it. In previous work1 a prototype assembly-oriented design environment incorporating DFA and assembly planning has been developed, integrated with CAD and supported by geometric reasoning algorithms. However, another opportunity to enhance the capabilities of the Sandpit is through the incorporation of functional representations. Functional modelling aims to bridge the gap between conceptual and detailed design and when addressed in a general context is a challenging research subject. Here, a functional modelling approach is proposed in the context of assembly-oriented CAD to facilitate the evaluation of product design in terms of manufacture, assembly and cost, before the geometry is defined.

Design Modification in a Collaborative Assembly Design Environment

2005 ◽  
Vol 6 (2) ◽  
pp. 200-208 ◽  
Author(s):  
C. Lu ◽  
J. Y. H. Fuh ◽  
Y. S. Wong ◽  
Z. M. Qiu ◽  
W. D. Li ◽  
...  
Keyword(s):  
Control Mechanism ◽  
The Internet ◽  
Design Environment ◽  
Detailed Design ◽  
Design Modification ◽  
Assembly Design ◽  
Geographically Dispersed ◽  
Collaborative Assembly ◽  
Feature Based

This paper discusses the design modification issue in a collaborative assembly (co-assembly) design environment, which enables multiple geographically dispersed designers to design and assemble parts collaboratively and synchronously through the Internet. An assembly representation model, viz. feature-based hierarchical co-assembly representation, is proposed to resolve the co-assembly design issues. In order to realize the design modification, a design modification propagation control mechanism is proposed. A system framework that is suitable for realizing the design modification is also proposed and developed. Finally, the detailed design modification propagation control mechanism is demonstrated through a case study.

scholarly journals On-Chip DNA Methylation Analysis Using Osmium Complexation

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Kaori Sugizaki ◽  
Tadashi Umemoto ◽  
Akimitsu Okamoto
Keyword(s):  
Dna Methylation ◽  
Research Subject ◽  
Methylation Analysis ◽  
Methylated Dna ◽  
Chemical Assay ◽  
Challenging Research ◽  
Detection Probe ◽  
On Chip ◽  
Dna Strand ◽  
Dna Methylation Analysis

The development of a reaction for detecting the presence/absence of one methyl group in a long DNA strand is a chemically and biologically challenging research subject. A newly designed chemical assay on a chip for the typing of DNA methylation has been developed. A methylation-detection probe fixed at the bottom of microwells was crosslinked with methylated DNA mediated by osmium complexation and contributes to selective amplification of methylated DNA.

Geometric Reasoning on Molding Planning for Multishot Mold Design

2006 ◽  
Vol 6 (3) ◽  
pp. 241-251 ◽  
Author(s):  
Zhou-Ping Yin ◽  
Han Ding ◽  
You-Lun Xiong
Keyword(s):  
Design Method ◽  
Automated Design ◽  
Geometric Reasoning ◽  
Geometric Constraints ◽  
Assembly Planning ◽  
Material Objects ◽  
Mold Design ◽  
Assembly Model ◽  
Contact Graph ◽  
Planning Approach

This paper presents algorithms for automated design of multishot molds for manufacturing multimaterial or multicolor objects, and focuses on molding planning that determines a sequence of mold stages required to produce the desired object. By modeling a multimaterial object as an assembly of homogenous components, a geometric reasoning approach is proposed to generate feasible or practical mold stage sequences by combining the assembly planning approach and the two-plate mold design method. First, a graph-based assembly model, namely the attributed contact graph, is derived from the B-rep models of the constituent components of the gross object by detecting and representing all the contacts between mating components explicitly. Then, all feasible mold stage sequences, represented by an AND/OR graph, are generated by reasoning on geometric constraints due to the demoldability and connectedness requirements using an assembly-by-disassembly strategy. Depending on its demoldability, each component is to be made by one of the three basic molding strategies with varied mold stages and/or mold pieces. To narrow the choice, an optimal or practical molding plan is searched from the feasible molding plans according to some criteria such as the number of mold stages, the number of side cores, and flatness of the parting line. Finally, starting from the last mold stage, mold pieces for each mold stage of the selected molding plan are constructed recursively. The feasibility of the proposed algorithms is demonstrated through an implemented prototypical system, which has been tested successfully with various multi-material objects.

Virtual Manufacturing Tools in the Product Design Environment

1999 ◽  
Author(s):  
Ronald C. Braun ◽  
Warren G. Marx
Keyword(s):  
Product Development ◽  
Product Design ◽  
Three Dimensional ◽  
Virtual Manufacturing ◽  
Assembly Planning ◽  
Shop Floor ◽  
Design Environment ◽  
Support Design ◽  
Simulation Tools ◽  
Lean Product Development

Abstract Design and manufacturing modeling and simulation have been identified as important to the principles of lean product development. Early in the product development cycle, the use of three-dimensional (3-D) engineering models allows us to electronically (or virtually) prototype physical products, and conduct product feasibility and producibility studies. Manufacturing issues can be identified early and used to drive the product design toward the lowest cost. This paper describes the Northrop Grumman Corporation (NGC) approach to extending classic prototype simulation to virtual manufacturing (VM) tools that accommodate the visualization of interacting production processes, process planning, scheduling, and assembly planning. Previous simulation tools were limited to the design environment. Our tools not only support design; they also provide functionality by bringing the results to the assembly floor. The use of these tools has resulted in “first-time quality” both above and on the shop floor, with significant reductions in product cost and cycle time.

Research on Knowledge-Based Virtual Assembly Planning

2007 ◽  
Vol 10-12 ◽  
pp. 435-439
Author(s):  
Bin Wang ◽  
D.F. Liu ◽  
P. Wang ◽  
Q.S. Xie
Keyword(s):  
Engineering Design ◽  
Virtual Assembly ◽  
Assembly Planning ◽  
Design Domain ◽  
Assembly Rules ◽  
Assembly Sequence ◽  
Design Environment ◽  
Assembly Design ◽  
Knowledge Based ◽  
Assembly Method

In order to find an optimum assembly sequence in engineering design domain, a knowledge-based virtual assembly approach was put forward. Virtual assembly design environment was also introduced, and knowledge representation models for virtual assembly rules and cases are introduced and studied respectively. A side-center virtual assembly method was applied to avoid the occurrence of assembly interference. Finally, a case was employed to demonstrate the practicality of knowledge-based virtual assembly planning.

Human–machine function allocation: a functional modelling approach

1999 ◽  
Vol 64 (2) ◽  
pp. 291-300 ◽  
Author(s):  
Andreas Bye ◽  
Erik Hollnagel ◽  
Tor Steinar Brendeford
Keyword(s):  
Functional Modelling ◽  
Function Allocation ◽  
Modelling Approach

Analysis of the bond graph model of hybrid physical systems with ideal switches

2002 ◽  
Vol 216 (1) ◽  
pp. 47-63 ◽  
Author(s):  
J Buisson ◽  
H Cormerais ◽  
P-Y Richard
Keyword(s):  
Graph Model ◽  
Bond Graph ◽  
State Equation ◽  
General Context ◽  
Knowledge Model ◽  
Implicit Representation ◽  
Physical Systems ◽  
Ideal Approach ◽  
Nilpotency Index ◽  
Modelling Approach

This paper deals with the modelling of hybrid physical systems. The bond graph technique is used to establish their knowledge model, based upon an ideal representation of the switches. These components are modelled either by flow or by effort sources according to their state and therefore modify the circuit topology at switching times. The paper shows the usefulness of the implicit representation to derive a unique implicit state equation with jumping parameters, to analyse the model properties, to derive an implicit state equation with nilpotency index one for each configuration and to compute the discontinuities. Also, a comparison between the chosen ideal modelling approach and the more common non-ideal approach is carried out using singular perturbations theory. After a presentation of the whole study in the most general context, its results are applied to power converters, which constitute a particular class of hybrid physical systems where switches only commutate in pairs. Finally, an example is developed.

Geometric Reasoning for Assembly Planning of Large Systems

2013 ◽  
Author(s):  
Ata A. Eftekharian ◽  
Charlie Manion ◽  
Matthew I. Campbell
Keyword(s):  
Geometric Reasoning ◽  
Assembly Planning ◽  
Tree Search ◽  
Ai Planning ◽  
Novel Approach ◽  
Assembly Sequences ◽  
Planning Procedure ◽  
Efficiency And Effectiveness ◽  
Large Systems ◽  
Optimal Assembly

Assembly planning is an important task for manufacturing industrial products. The ability to automate and optimize the process is crucial as it can improve the production time, cost and efficiency. In general, the planning procedure involves two main reasoning stages, one is based on geometric reasoning and the other is based on AI tree-search. In this article, a novel approach to automate the geometric reasoning stage for large assembly systems is proposed. This technique provides a fast and accurate measure of capturing feasible spatial interactions and relationships between elements of a CAD assembly with no manual interventions. These results are then used by a suite of AI planning tools to generate optimal assembly sequences. The algorithm has been tested on a variety of examples resembling real products and results show the efficiency and effectiveness of the algorithm.

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