Stream-of-Variation (SOVA) Modeling II: A Generic 3D Variation Model for Rigid Body Assembly in Multistation Assembly Processes

2007 ◽  
Vol 129 (4) ◽  
pp. 832-842 ◽  
Author(s):  
Wenzhen Huang ◽  
Jijun Lin ◽  
Zhenyu Kong ◽  
Dariusz Ceglarek
Keyword(s):  
Tolerance Analysis ◽  
Computation Efficiency ◽  
Simulation Based ◽  
Automatic Model Generation ◽  
Stream Of Variation ◽  
Product And Process ◽  
Process Factors ◽  
Industrial Software ◽  
Backward Analysis ◽  
Multistation Assembly

A 3D rigid assembly modeling technique is developed for stream of variation analysis (SOVA) in multi-station processes. An assembly process is modeled as a spatial indexed state transition dynamic system. The model takes into account product and process factors such as: part-to-fixture, part-to-part, and inter-station interactions, which represent the influences coming from both tooling errors and part errors. The incorporation of the virtual fixture concept (Huang et al., Proc. of 2006 ASME MSEC) and inter-station interaction leads to the generic, unified SOVA model formulation. An automatic model generation technique is also developed for surmounting difficulties in modeling based on first principles. It enhances the applicability in modeling complex assemblies. The developed SOVA methodology outperforms the current simulation based techniques in computation efficiency, not only in forward analysis of complex assembly systems (tolerance analysis, sensitivity analysis), but it is also more powerful in backward analysis (tolerance synthesis and dimensional fault diagnosis). The model is validated using industrial case studies and series of simulations conducted using standardized industrial software (3DCS Analyst).

Stream-of-Variation (SOVA) Modeling II: A Generic 3D Variation Model for Rigid Body Assembly in Multi Station Assembly Processes

2006 ◽  
Author(s):  
Wenzhen Huang ◽  
Jijun Lin ◽  
Zhenyu Kong ◽  
Dariusz Ceglarek
Keyword(s):  
Tolerance Analysis ◽  
Model Formulation ◽  
Computation Efficiency ◽  
Simulation Based ◽  
Automatic Model Generation ◽  
Stream Of Variation ◽  
Product And Process ◽  
Process Factors ◽  
Industrial Software ◽  
Backward Analysis

A 3D rigid assembly modeling technique is developed for stream of variation analysis (SOVA) in multi-station processes. An assembly process is modeled as a spatial indexed state transition dynamic system. The model takes into account product and process factors such as: part-to-fixture, part-to-part and inter-station interactions, which represent the influences coming from both tooling errors and part errors. The incorporation of the virtual fixture concept [14] and inter-station interaction leads to the generic, unified SOVA model formulation. An automatic model generation technique is also developed for surmounting difficulties in modeling based on first principles. It enhances the applicability in modeling complex assemblies. The developed SOVA methodology outperforms the current simulation based techniques in computation efficiency, not only in forward analysis of complex assembly systems (tolerance analysis, sensitivity analysis), but it is also more powerful in backward analysis (tolerance synthesis and dimensional fault diagnosis). The model is validated using industrial case studies and series of simulations conducted using standardized industrial software (3DCS).

Stream-of-Variation Modeling—Part I: A Generic Three-Dimensional Variation Model for Rigid-Body Assembly in Single Station Assembly Processes

2007 ◽  
Vol 129 (4) ◽  
pp. 821-831 ◽  
Author(s):  
Wenzhen Huang ◽  
Jijun Lin ◽  
Michelle Bezdecny ◽  
Zhenyu Kong ◽  
Dariusz Ceglarek
Keyword(s):  
Rigid Body ◽  
Manufacturing Systems ◽  
Three Dimensional ◽  
Single Station ◽  
Generic Modeling ◽  
Stream Of Variation ◽  
Product And Process ◽  
Industrial Software ◽  
Multistation Assembly ◽  
Relationship Of

A stream-of-variation analysis (SOVA) model for three-dimensional (3D) rigid-body assemblies in a single station is developed. Both product and process information, such as part and fixture locating errors, are integrated in the model. The model represents a linear relationship of the variations between key product characteristics and key control characteristics. The generic modeling procedure and framework are provided, which involve: (1) an assembly graph (AG) to represent the kinematical constraints among parts and fixtures, (2) an unified method to transform all constraints (mating interface and fixture locators etc.) into a 3-2-1 locating scheme, and (3) a 3D rigid model for variation flow in a single-station process. The generality of the model is achieved by formulating all these constraints with an unified generalized fixture model. Thus, the model is able to accommodate various types of assemblies and provides a building block for complex multistation assembly model, in which the interstation interactions are taken into account. The model has been verified by using Monte Carlo simulation and a standardized industrial software. It provides the basis for variation control through tolerance design analysis, synthesis, and diagnosis in manufacturing systems.

Stream-of-Variation Modeling I: A Generic 3D Variation Model for Rigid Body Assembly in Single Station Assembly Processes

2006 ◽  
Author(s):  
Wenzhen Huang ◽  
Jijun Lin ◽  
Michelle Bezdecny ◽  
Zhenyu Kong ◽  
Dariusz Ceglarek
Keyword(s):  
Rigid Body ◽  
Manufacturing Systems ◽  
Assembly Model ◽  
Single Station ◽  
Generic Modeling ◽  
Rigid Model ◽  
Stream Of Variation ◽  
Product And Process ◽  
Industrial Software ◽  
Relationship Of

A stream-of variation analysis (SOVA) model for 3D rigid body assemblies in single station is developed. Both product and process information such as part and fixture locating errors are integrated in the model. The model represents a linear relationship of the variations between Key Product Characteristics (KPCs) and Key Control Characteristics (KCCs). The generic modeling procedure and framework are provided, which involves: (1) an assembly graph (AG) to represent the kinematical constraints among parts and fixtures; (2) a unified method to transform all constraints (mating interface and fixture locators etc.) into a 3-2-1 locating scheme; and (3) a 3D rigid model for variation flow in a single station. The generality of the model is achieved by formulating all these constraints with a unified generalized fixture model. Thus, the new model accommodates various types of assemblies. This model provides a building block for complex multi station assembly model, in which the inter-station interactions are taken into account. The model has been verified by using Monte Carlo (MC) simulation and a standardized industrial software. It provides the basis for variation control through tolerance design analysis, synthesis and diagnosis in manufacturing systems.

Research on Angular Variation for Aeroplane-Assembly Base on State Space Model

2013 ◽  
Vol 278-280 ◽  
pp. 149-154 ◽  
Author(s):  
Xin Li ◽  
Zhi Xiong Zhang ◽  
Jian Zhong Shang ◽  
Yu Jun Cao
Keyword(s):  
State Space ◽  
State Space Model ◽  
Variation Analysis ◽  
Space Model ◽  
Computation Efficiency ◽  
Assembly Accuracy ◽  
Simulation Based ◽  
Different Types ◽  
Stream Of Variation ◽  
Types Of Error

Abstract. Variation modeling is one of the most significant tools for assembly variation analysis. Considering dimension and geometric errors, and part situation errors, the error source that affects assembly accuracy is classified into two types: error of geometric location and orientation, error of geometric form. And unify these different types of error or deviation by the concept of Virtual Fixture. So a rigid assembly state space model is developed for stream of variation analysis in multi-station assembly processes. And an aeroplane-cabin-assembly process is analyzed in this model. The developed methodology outperforms the current simulation based techniques in computation efficiency, the model is validated using Monte Carlo series Simulations.

Analysis and Control of Car Door Inner Panel Forming Fracture Based on Experience Knowledge and Numerical Simulation

2011 ◽  
Vol 189-193 ◽  
pp. 2567-2571
Author(s):  
Hua Ying Wu ◽  
Chen Guo ◽  
Chun Hui Xiao
Keyword(s):  
Numerical Simulation ◽  
Hole Radius ◽  
Test Pieces ◽  
Simulation Based ◽  
Door Panel ◽  
Forward Engineering ◽  
Stamping Direction ◽  
Process Factors ◽  
Bead Height ◽  
And Control

The process factors influencing the forming quality of car inner door panel such as stamping direction, binder surface, draw-bead, addendum surface and technical cut are determined based on experience knowledge. Aiming at local fracture problem of test pieces, some key parameters are determined based on experience knowledge, and the strain in thinning area of sheet metal forming is analyzed by numerical simulation. Based on this, process optimization and die modification scheme are put forward. Engineering inspection proved that optimized process and die parameters are reasonable, after increasing die fillet radius and process hole radius, decreasing draw-bead height, qualified products are achieved and fracture flaw is well controlled.

Simulation-Based Tolerance and Assemblability Analyses of Assemblies With Multiple Pin/Hole Floating Mating Conditions

2005 ◽  
Author(s):  
Zhengshu Shen ◽  
Jami J. Shah ◽  
Joseph K. Davidson
Keyword(s):  
Tolerance Analysis ◽  
Virtual Manufacturing ◽  
Product Development Process ◽  
3D Analysis ◽  
Dimensional Problem ◽  
Press Fit ◽  
Simulation Based ◽  
The Difference ◽  
2D And 3D ◽  
Mating Conditions

Development of tolerance analysis methods that are consistent with the ASME and ISO GD&T (geometric dimensioning and tolerancing) standards is a challenging task. Such methods are the basis for creating computer-aided tools for 3D tolerance analysis and assemblability analysis. These tools, along with the others, make it possible to realize virtual manufacturing in order to shorten lead-time and reduce cost in the product development process. Current simulation tools for 3D tolerance analysis and assemblability analysis are far from satisfactory because the underlying variation algorithms are not fully consistent with the GD&T standards. Better algorithms are still to be developed. Towards that goal, this paper proposes an improved simulation-based approach to tolerance and assemblability analyses for assemblies with pin/hole floating mating conditions in mechanical products. A floating pin/hole mating condition is the one where the mating pin should be able to “float” within the mating hole, and thus press-fit is not necessary for the parts to assemble properly. When multiple pin/hole mating pairs are involved in a product, the feasibility of assembly needs to be analyzed. This paper will introduce a more complete method of analyzing assemblability for such assemblies. In most cases, a 3D (3-dimensional) problem can be simplified to 1D (1-dimensional) or 2D (2-dimensional) problem, with the loss of some accuracy. To make a comparison and find out how accurately 1D and 2D analyses can approximate 3D analysis, this paper will provide the variation algorithms for 1D, 2D and 3D simulations. The algorithms developed account not only for bonus/shift tolerances but also for feasibility of assembling. These algorithms are extendable to consider other different GD&T specifications. The assemblability criteria proposed is generally applicable to any assemblies with pin/hole floating mating conditions. Case studies are provided to demonstrate the algorithms developed. The comparison study shows quantitatively the difference in the results from 1D, 2D and 3D simulation based analyses.

A Comparative Study of Tolerance Analysis Methods

2004 ◽  
Author(s):  
Zhengshu Shen ◽  
Gaurav Ameta ◽  
Jami J. Shah ◽  
Joseph K. Davidson
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Tolerance Analysis ◽  
3 Dimensional ◽  
Analysis Methods ◽  
Simulation Based ◽  
Comprehensive Comparison ◽  
Tolerance Charts ◽  
Assembly Constraints ◽  
Tolerance Accumulation

This paper reviews four major methods for tolerance analysis and compares them. The methods discussed are (1) 1D tolerance charts, (2) variational analysis based on Monte Carlo simulation, (3) vector loop (or kinematic) based analysis, and (4) ASU T-Maps© based tolerance analysis. Tolerance charts deal with tolerance analysis in one direction at a time and ignore possible contributions from the other directions. Manual charting is tedious and error-prone, hence attempts have been made for automation. Monte Carlo simulation based tolerance analysis is based on parametric solid modeling; its inherent drawback is that simulation results highly depend on the user-defined modeling scheme, and its inability to obey all Y14.5 rules. The vector loop method uses kinematic joints to model assembly constraints. It is also not fully consistent with Y14.5 standard. ASU T-Maps based tolerance analysis method can model geometric tolerances and their interaction in truly 3-dimensional context. It is completely consistent with Y14.5 standard but its use by designers may be quite challenging. T-Maps based tolerance analysis is still under development. Despite the shortcomings of each of these tolerance analysis methods, each may be used to provide reasonable results under certain circumstances. No guidelines exist for such a purpose. Through a comprehensive comparison of these methods, this paper will develop some guidelines for selecting the best method to use for a given tolerance accumulation problem.

scholarly journals HOW TUTORING BUSINESS AGENCY SURVIVES IN THE MIDST OF THE PANDEMIC COVID-19?

2021 ◽  
Vol 5 (2) ◽  
pp. 172-178
Author(s):  
Eka Indah Nurlaili ◽  
Fajar Budiyanto
Keyword(s):  
Formal Education ◽  
School Curriculum ◽  
Education Sector ◽  
Educational Institutions ◽  
Face To Face ◽  
Offline Learning ◽  
Face To Face Learning ◽  
Product And Process ◽  
Process Factors ◽  
Temporary Closure

The temporary closure of formal educational institutions in an effort to contain the spread of the Covid-19 epidemic around the world has an impact on the education sector, not except in Indonesia. The non-formal education sector, such as the Tutoring Business Agencies, also experienced a very significant impact, where the tutoring agencies had difficulty in implementing the marketing mix. So that further studies are needed so that the tutoring business agencies will survive in a pandemic condition. To obtain data, it was done through literature studies from secondary and qualitative data. The habits of students who tend to prefer face-to-face activities make online tutoring activities less responsive and still choose face-to-face learning as one way to keep up with the school curriculum. The solution so that tutoring agencies can survive is to improve product and process factors. The products include limiting the number of students in the class and the variety of online and offline learning. The process is by spraying disinfectant at each class change and providing distance between students. This needs to be done so that parents who provide the needed funds will feel safe when their children study at the desired tutoring agencies.

A Complete Variation Algorithm for Slot and Tab Features for 3D Simulation-Based Tolerance Analysis

2005 ◽  
Author(s):  
Zhengshu Shen ◽  
Jami J. Shah ◽  
Joseph K. Davidson
Keyword(s):  
Tolerance Analysis ◽  
Virtual Manufacturing ◽  
3D Simulation ◽  
Product Development Process ◽  
Simulation Tools ◽  
Geometric Dimensioning And Tolerancing ◽  
Material Condition ◽  
Tolerance Chart ◽  
Simulation Based ◽  
Mechanical Products

Development of tolerance analysis methods that are consistent with the ASME and ISO GD&T (geometric dimensioning and tolerancing) standards is a challenging task. Such methods are the basis for creating computer-aided tools for 3D tolerance analysis and assemblability analysis. These tools, along with the others, make it possible to realize virtual manufacturing, in order to shorten lead-time and reduce cost in the product development process. Current simulation tools for 3D tolerance analysis and assemblability analysis are far from satisfactory because the underlying variation algorithms are not fully consistent with the GD&T standards. Better algorithms are still to be developed. Towards that goal, this paper proposes a complete algorithm for 3D slot features and tab features (frequently used in mechanical products) for 3D simulation-based tolerance analysis. The algorithms developed account for bonus/shift tolerances (i.e. effects from material condition specifications), and tolerance zone interaction when multiple tolerances are specified on the same feature. A case study is conducted to demonstrate the algorithm developed. The result from this work is compared with that from 1D tolerance chart method. The comparison study shows quantitatively why 1D tolerance chart method, which is popular in industry, is not sufficient for tolerance analysis, which is 3D in nature.

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