Development of an Ethernet-based data acquisition system of resistance spot welding for white-body assembly

The resistance spot welding plays an important role in automotive industry. The electrical parameters (power supply voltage, welding current, SCR firing angle and current flow angle) of welding process can reflect the quality of joint and the status of welding equipment, many data acquisition devices designed to collect those parameters have been discussed in many papers, but there is such a deficiency that one computer can only link with an acquisition device. At automobile assembly field, there are hundreds of welding machines working at the same time, so the existing device can not be satisfied with manufacturing demand. To solve the problem, the double-MCU data acquisition device based on Ethernet is discussed in this paper, the data acquisition devices can altogether link with a computer using a HUB, the effective value or the instantaneous value of electrical parameters can be transmitted to the computer over UDP/IP. All the data are read through Ethernet port of a computer using a LabView application, which can process, store and present all data to the user. Finally the experiments prove that the designed Ethernet-based data acquisition system is suitable for practical application. © Editorial Board of CHINA WELDING.