基于动态电阻理论的SVR点焊质量评估方法

针对电阻点焊质量评估方法大多采用破坏性试验进行检验，提出采用支持向量回归机模型预测点焊熔核直径的方法对焊点进行无损检测。电阻点焊过程具有高度非线性、多变量耦合及偶然不确定因素，且熔核形成过程时间极短。因此根据电阻点焊动态电阻理论，选择径向基核函数作为支持向量回归机的核函数，选择对电阻点焊熔核直径有直接影响的焊接电流、焊接时间等主要焊接参数构造样本数据，建立支持向量回归模型机。对建立的预测模型进行参数寻优，并进行了计算机仿真试验。结果表明，采用支持向量回归机能够较为准确的预测电阻点焊的熔核直径。

The Method of Evaluating Spot Welding Quality withSupport Vector Regression Based on Dynamic Resistance Theory

Aiming at the destructive test method for resistance spot welding quality, a non-destructive test of the solder joints is proposed by using the support vector regression model to predict the diameter of the spot weld nugget. The resistance spot welding process has highly nonlinear, multivariable coupling and accidental uncertainties, and the nugget formation process time is extremely short. The sample data are constructed by choosing these main welding parameters such as welding current and welding time，which have direct effects on resistance spot welding nugget diameter. The parameters of the prediction model are optimized according to the constructed sample data. The computer simulation test of the model has been carried out. The simulation results show that the model can predict the nugget diameter accurately.