Research Of Signal Acquisition And Analysis System For Spot Welding

Real-time monitoring of spot welding is a main task of automation and computerization, and also is a key to improve spot welding quality. There are many welding researchers at home and abroad committed real-time monitoring of spot welding and have made some achievements, but still exist inadequacies in the field of defect identification. Because of all above, a data acquirement system for spot welding based on virtual instruments was built in this study, and proposed a theory of defect identification, to identify splashing and incomplete fusion.By research on data acquirement, chose suitable sensors and make corresponding interface circuit, and acquire data of voltage,current,electrode displacement and press of spot welding, and transform physical signal to digital signal by data acquisition card and transmit into a computer, finally save these digital signal as binary files that the computer can read by data acquirement system based on virtual instruments.Analyzing the acquired data, finding there are quality information of spot welding joints hiding in it. In order to identify splashing and incomplete fusion, build the defect identification system. The system can not only judge whether a joint eligible, it also can present criterion at a certain welding parameter.By academic analysis and practical operation, realize real-time monitoring and data acquirement for spot welding successfully. Base on data acquirement, the system solve the problem of defect identification, and offer a new thought and new method for automatization of spot welding.