On-Line Estimation of Electrode Face Diameter Based on Servo Gun Driven by Robot in Resistance Spot Welding

2007 ◽  
pp. 195-202
Author(s):  
X. M. Lai ◽  
X. Q. Zhang ◽  
G. L. Chen ◽  
Y. S. Zhang
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Resistance Spot ◽  
On Line

Contact Area Modeling and On-Line Estimation in Resistance Spot Welding

Manufacturing ◽  
2002 ◽  
Author(s):  
Wei Li
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Process Conditions ◽  
Electrode Wear ◽  
Welding Time ◽  
Contact Areas ◽  
Resistance Spot ◽  
On Line

Contact areas at both electrode-to-sheet and sheet-to-sheet interfaces are important in the resistance spot welding process. Given electrode force and welding time, contact areas strongly affect the amount of electrical current needed to make a good weld. In production, process variation such as electrode wear and misalignment causes the contact areas to vary. This effect contributes largely to the quality variation of resistance spot welds. This paper proposes a model-based approach to contact area estimation in the resistance spot welding process. A finite element analysis procedure is used to characterize the contact area behaviors. Based on the understanding from the simulations, a lumped parameter model, together with its calibration and estimation procedures, is developed for on-line applications. The proposed method is demonstrated successful under various process conditions including electrode size, force, welding time and current. It provides important information for on-line monitoring and control of the resistance spot welding process.

Modeling and On-Line Estimation of Electrode Wear in Resistance Spot Welding

2004 ◽  
Vol 127 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Wei Li
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Estimation Algorithm ◽  
Contact Condition ◽  
Electrode Wear ◽  
Resistance Spot ◽  
On Line

Electrode wear is inherent in the resistance spot welding process. It determines the electrical and mechanical contact condition and thus strongly affects the resistance spot weld quality. A practical approach to minimizing the electrode wear effect is to compensate the welding current as the electrodes wear. However, the existing methods for welding current compensation rely on either a predetermined stepper schedule or an expulsion detection algorithm. These methods are not reliable since the welding current is not determined based on the contact condition for each weld made in the welding process. This paper presents an on-line electrode wear estimation approach to determining the contact condition and the welding current needed to make every weld a good weld during the entire life of the electrodes. In the study, an incrementally coupled finite element simulation was first formulated to analyze the contact area behavior in the resistance spot welding process. A lumped parameter model was then developed to characterize the contact area change with the dynamic resistance measurement. A calibration and an estimation algorithm were subsequently devised for on-line applications. The proposed approach has been validated with experimental data. The results have shown that the estimation algorithm is robust under various process conditions including both welding current and electrode force.

Dynamic Resistance Based Model for On-Line Resistance Spot Welding Quality Assessment

2012 ◽  
Vol 706-709 ◽  
pp. 2925-2930 ◽  
Author(s):  
Abderrazak El Ouafi ◽  
R. Belanger ◽  
Michel Guillot
Keyword(s):  
Quality Assessment ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Assessment Model ◽  
Welding Parameters ◽  
Dynamic Resistance ◽  
Weld Quality ◽  
Quality Estimation ◽  
Resistance Spot ◽  
On Line

On-line quality assessment becomes one of the most critical requirements for improving the efficiency of automatic resistance spot welding (RSW) processes. Accurate and efficient model to perform non-destructive quality estimation is an essential part of the assessment. Besides the usual welding parameters, various measured variables have been considered for quality estimation in RSW. Among these variables, dynamic resistance (DR) gives a relative clear picture of the welding nugget formation and presents a significant correlation with the RSW quality indicators (QI). This paper presents a structured approach developed to design an effective DR-based model for on-line quality assessment in RSW. The proposed approach examines welding parameters and conditions known to have an influence on weld quality, and builds a quality assessment model step by step. The modeling procedure begins by examining, through a structured experimental design, the relationships between welding parameters, typical characteristics of the RD curves and multiple welding QI. Using these results and various statistical tools, different integrated quality assessment models combining an assortment of DR attributes are developed and evaluated. The results demonstrate that the proposed approach can lead to a general model able to accurately and reliably provide an appropriate assessment of the weld quality under variable welding conditions.

On-line Quality Estimation in Resistance Spot Welding

1999 ◽  
Vol 122 (3) ◽  
pp. 511-512 ◽  
Author(s):  
Wei Li ◽  
S. Jack Hu ◽  
Jun Ni
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Selection Procedure ◽  
Resistance Force ◽  
Dynamic Resistance ◽  
Electrode Wear ◽  
Size Estimation ◽  
Resistance Spot ◽  
Electrode Displacement ◽  
On Line

A neural network model is developed for on-line nugget size estimation in resistance spot welding. The variables used consist of features extracted from both controllable process input variables and on-line signals. A systematic signal and feature selection procedure is developed. The three commonly observed on-line signals, dynamic resistance, force, and electrode displacement, have been proven to carry similar information. Thus, only dynamic resistance is used in the model. The obtained model has been demonstrated to be robust over various welding conditions including electrode wear. [S1087-1357(00)01204-1]

scholarly journals Review on Techniques for On-Line Monitoring of Resistance Spot Welding Process

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yanhua Ma ◽  
Pei Wu ◽  
Chuanzhong Xuan ◽  
Yongan Zhang ◽  
He Su
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Resistance Spot ◽  
On Line

An On-Line ANN-Based Approach for Quality Estimation in Resistance Spot Welding

2010 ◽  
Vol 112 ◽  
pp. 141-148 ◽  
Author(s):  
Abderrazak El Ouafi ◽  
Rudy Bélanger ◽  
Jean-François Méthot
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Parameters ◽  
Dynamic Resistance ◽  
Resistance Curve ◽  
Weld Quality ◽  
Estimation Model ◽  
Quality Estimation ◽  
Resistance Spot ◽  
On Line

The aim of this study is to develop an effective on-line ANN-based approach for quality estimation in resistance spot welding. The proposed approach examines the welding parameters and conditions known to have an influence on weld quality, and builds a quality estimation model step by step. The modeling procedure begins by establishing relationships between welding parameters (welding time, welding current, electrode force and sheet metal thickness), welding conditions represented by typical characteristics of the dynamic resistance curve and welding quality indices (nugget diameter, nugget penetration, and indentation depth), and the sensitivity of these elements to the variation of the process conditions. Using these results and various statistical tools, three estimation models are developed. The first one is based exclusively on welding parameters. The second model is based on characteristics of the dynamic resistance curve. The third estimation model combines welding parameters and characteristics of dynamic resistance curves. In order to carry out the models building procedure, an extensive number of welding experiments are required. For this purpose, Taguchi’s efficient method of experimental planning is adopted. The results demonstrate that the developed models can provide an accurate on-line estimate of the weld quality, under different welding conditions.

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