Variation Analysis for Compliant Assembly

2000 ◽  
Author(s):  
S. Jack Hu ◽  
Yufeng Long ◽  
Jaime Camelio
Keyword(s):  
Sheet Metal ◽  
Assembly Line ◽  
Assembly Process ◽  
Variation Analysis ◽  
Assembly Lines ◽  
Compliant Assembly ◽  
Single Station ◽  
Dimensional Variation ◽  
Sheet Metal Assembly

Abstract Assembly processes for compliant non-rigid parts are widely used in manufacturing automobiles, furniture, and electronic appliances. One of the major issues in the sheet metal assembly process is to control the dimensional variation of assemblies throughout the assembly line. This paper provides an overview of the recent development in variation analysis for compliant assembly. First, the unique characteristics of compliant assemblies are discussed. Then, various approaches to variation modeling for compliant assemblies are presented for single station and multi-station assembly lines. Finally, examples are given to demonstrate the applications of compliant assembly variation models.

Compliant assembly variation analysis of sheet metal with shape errors based on primitive deformation patterns

2017 ◽  
Vol 232 (13) ◽  
pp. 2334-2351 ◽  
Author(s):  
Yunyong Li ◽  
Yong Zhao ◽  
Haidong Yu ◽  
Xinmin Lai
Keyword(s):  
Sheet Metal ◽  
Propagation Model ◽  
Surface Shape ◽  
Mode Analysis ◽  
Assembly Process ◽  
Variation Analysis ◽  
Compliant Assembly ◽  
Variation Propagation ◽  
Shape Errors ◽  
Deformation Patterns

In the compliant assembly of sheet metal, the performance of the product is highly related to the shape errors of surface. Therefore, variation analysis is generally required to reveal the influence principle of the components’ manufacturing variations on the surface shape errors of the product. The traditional compliant assembly variation analysis methods were used to build a variation propagation model based on characteristic points between parts and product without considering shape errors. In this paper, a new method based on primitive deformation patterns considering shape errors is proposed. The primitive deformation patterns of part can be obtained by natural mode analysis of ideal part, and the primitive deformation patterns of product can be calculated by the dynamic substructure method. The initial shape errors of part are decomposed into the individual contributions of primitive deformation patterns. Considering the force equilibrium relationship in assembly process, a variation propagation model is built based on the primitive deformation patterns between parts and product. This model reveals variation propagation in assembly process by the basic element of dimension error field (deformation patterns), which is convenient for evaluating the assembly quality. A case study on a panel parts assembly process is presented to demonstrate the proposed variation analysis method. The results show the effectiveness and accuracy of the proposed method compared with the method of finite element analysis conducted in commercial software ABAQUS.

Optimization on the Bottleneck Process of 63PF2 Conveying Chain Assembly

2011 ◽  
Vol 308-310 ◽  
pp. 734-738
Author(s):  
Ai Ying Meng
Keyword(s):  
Assembly Line ◽  
Flow Analysis ◽  
Assembly Process ◽  
Assembly Lines ◽  
Operation Analysis ◽  
Work Measurement ◽  
Analysis Process ◽  
Transmission Chain ◽  
Fishbone Diagram ◽  
Low Efficiency

Aiming at the problem of more difficult and low efficiency to assembly 63PF2 conveying chain, the work measurement, action research and production line balancing method are studied, and the data of 63PF2 conveying chain assembly lines is obtained. Taking 63PF2 conveying chain assembly lines for example and using industrial engineering foundation of stopwatch time study, two-handed operation analysis, process flow analysis and quality management of fishbone diagram, the problems existing in 63PF2 conveying chain assembly process are analyzed. And then the work site preliminary optimization is carried out. The bottleneck process of assembly process is optimized and improved. And the balance of assembly line is optimized, so as to improve the transmission chain assembly efficiency.

Compliant Assembly Variation Analysis Using Components Geometric Covariance

Manufacturing ◽  
2002 ◽  
Author(s):  
Jaime A. Camelio ◽  
S. Jack Hu
Keyword(s):  
Principal Component Analysis ◽  
Finite Element ◽  
Sheet Metal ◽  
Finite Element Methods ◽  
Principal Component ◽  
Deformation Mode ◽  
Component Analysis ◽  
Variation Analysis ◽  
The Individual ◽  
Sheet Metal Assembly

Dimensional variation is one of the most critical issues in the design of assembled products. This is especially important for the assembly of compliant, non-rigid parts since clamping and joining during assembly may introduce additional variation due to part deformation and springback. This paper presents a new methodology to predict sheet metal assembly variation using the components geometric covariance. The approach combines the use of principal component analysis and finite element methods to estimate the effect of components variation on assembly variation. Principal component analysis is applied to extract deformation patterns from production data, decomposing the component covariance in the individual contribution of these deformation “modes”. Finite element methods are used to determine the effect of each deformation “mode” over the assembly variation. The proposed methodology allows significant reduction in the computation effort required for variation analysis in sheet metal assembly. A case study is presented to illustrate the methodology.

Minimizing Geometric Variation in Multistage Assembly Lines by Geometrical Decoupling

2011 ◽  
Author(s):  
Peter Edholm ◽  
Lars Lindkvist ◽  
Rikard So¨derberg
Keyword(s):  
Assembly Line ◽  
Manufacturing Companies ◽  
Assembly Lines ◽  
Root Cause ◽  
Geometrical Quality ◽  
Geometrical Variation ◽  
Definition Of ◽  
Geometric Variation ◽  
Sheet Metal Assembly

Geometrical part robustness is used today as an engineering criterion in many manufacturing companies. The goal is to minimize the effect of geometrical variation by optimizing the locating schemes for the parts. Several methods and tools now exist to support geometrical robustness optimization for parts, but also for assemblies. In this paper the focus is on geometrical decoupling, which is one parameter of geometrical robustness of the different locating strategies in a complete assembly line. A goodness value is proposed that describes the level of geometrical couplings in a complete assembly line together with the part robustness value. By calculating this goodness value it is possible to predict the geometrical sensitivity of a complete assembly line as well as predicting the risk of geometrical variation in the final product. To illustrate the definition of this goodness value, and also the purpose of calculating it, a case study is used where a part of a sheet metal assembly line is described. Several different scenarios (assembly concepts) are applied to clarify the meaning and to validate this definition of the goodness value. The case study shows that the goodness value gives a good indication of the level of geometrical couplings within the assembly line and that this value can be used to evaluate different assembly concepts, with their locating concepts, against each other. The goal is to have a more robust and also geometrically decoupled assembly line which enables root-cause analysis in production, and also optimizes the geometrical quality minimizing the effect of geometrical variation of the final product from the plant.

A genetic algorithm-based fixture locating positions and clamping schemes optimization

2003 ◽  
Vol 217 (8) ◽  
pp. 1075-1083 ◽  
Author(s):  
Y G Liao
Keyword(s):  
Genetic Algorithm ◽  
Sheet Metal ◽  
Optimization Method ◽  
Form Accuracy ◽  
Dimensional Variation ◽  
Stationary Set ◽  
Machining Fixtures ◽  
Sheet Metal Assembly ◽  
Industrial Part ◽  
Selection Of

Optimizing the locator positions and clamping schemes of a fixture was proven to improve the dimensional and form accuracy of a workpiece significantly. A number of approaches have been developed to optimize the designs of sheet-metal assembly fixtures and machining fixtures. However, in these previous works, the optimal selection of the positions of locators and clamps were based on a stationary set of locator and clamp conditions; i.e. the numbers of the locators and clamps were fixed during optimization. This paper proposes a genetic algorithm (GA)-based optimization method to select automatically the optimal numbers of locators and clamps as well as their optimal positions in sheet-metal assembly fixtures, such that the workpiece deformation due to the gravity effect and resulting variation due to part dimensional variation are simultaneously minimized. The application result of a real industrial part demonstrated that the proposed algorithm effectively achieves the objective.

A Genetic Algorithm Approach to Weld Pattern Optimization in Sheet Metal Assembly

2003 ◽  
Author(s):  
Gene Y. Liao
Keyword(s):  
Genetic Algorithm ◽  
Sheet Metal ◽  
Optimization Method ◽  
Structural Deformation ◽  
Assembly Process ◽  
Sheet Metal Parts ◽  
Final Assembly ◽  
Welding Operation ◽  
Genetic Algorithm Approach ◽  
Sheet Metal Assembly

In sheet metal assembly process, welding operation joins two or more sheet metal parts together. Since sheet metals are subject to dimensional variation resulted from manufacturing randomness, gap may be generated at each weld pair prior to welding. These gaps are forced to close during a welding operation and accordingly undesirable structural deformation results. Optimizing the welding pattern (the number and locations of weld pairs) of an assembly process was proven to significantly improve the quality of final assembly. This paper presents a Genetic Algorithm (GA)-based optimization method to automatically search for the optimal weld pattern so that the assembly deformation is minimized. Application result of a real industrial part demonstrated that the proposed algorithm effectively achieve the objective.

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