Aluminium alloy resistance spot welding nugget size real-time detection process

Abstract

The invention relates to a method of real-time detection for the spot welding nugget diameter of an aluminium alloy resistance, which includes the following steps:1. acquiring the electrode displacement signals in the process of spot welding and drawing the curve diagram of the electrode displacement signals;2. extracting the two eigenvalues of expansion displacement and forging displacement;3. unripping the aluminium alloy welding board, measuring the spot welding nugget diameter of the resistance and constructing a couple-sample corresponding to the extracted eigenvalues and the measured nugget diameters;4.repeating the steps 2 and 3 so as to obtaining the couple-samples with the required quantity for design; 5.constructing an artificial neural network model and carrying out training with the obtained couple-samples according to BP algorithm so as to realizing the mapping from the eigenvalue to nugget diameter, wherein the artificial neural network model has two inputs, one output and an implicit strata in the middle, which has five nodes and the transfer function of which is Sigmoid function, and the transfer function of the output layer is linear function; 6.applying the trained model to the real-time detection for the spot welding nugget diameter of an aluminium alloy resistance.

Description

Technical field [0001] The present invention relates to a welding quality detection technology, in particular to a method for real-time detection of aluminum alloy resistance spot welding nugget diameter by using computer technology. The international patent classification number is proposed to be Int.Cl.G01D21 / 02 (2006.01). Background technique [0002] Since the welding joint formation process of resistance spot welding is closed, it is impossible to directly observe the condition of the welding area, so it is more difficult to judge the quality of spot welding. Traditionally, the method of spot welding quality inspection is to judge by radiographic inspection, ultrasonic inspection, destructive inspection after welding or relying on the operator's experience. In recent years, the method of detecting the quality of the solder joints by detecting the process parameters of the spot welding process has been in-depth research. When using spot welding process parameters to detect th...

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Problems solved by technology

This method can be applied to the electric welding detection of aluminum alloy materials, but it uses ultrasonic method to detect the nugget diameter, which requires the ultrasonic probe to be well coupled with the upper and lower surfaces of the weldment, so it is difficult to apply to the real-time detection of the spot welding site

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