| Resistance spot welding is one of the main methods which is used widely in all aspects of the modern production. According to the data, the quantity used by the spot welding is about 33 percent of that used by overall welding method. The check-up of the welding quality is an important aspect in the process of the welding which can control the welding quality and avoid the waster. Now guarantee every welding spot is crucial to the welding quality.Resistance spot welding has large welding current, short welding time and its many disturb factors affect each other. The welding procession is instantaneous and the formation of the spot is sightless. So the welder cannot find out the problem and make reaction in time. Research shows that dynamic signal of resistance spot welding process contains a lot of information, which directly or indirectly reflect the welding nugget quality. For resistance spot welding, the connection intensity of welding spot mainly decided by geometry dimension of the welding nugget, and which are controlled by many spot welding process parameters, such as welding current, welding period, electrode force and so on. In addition, some process features such as spot welding electrode voltage, dynamic resistance also reflect the welding spot quality information from one aspect. Therefore the monitor of technology parameters of spot welding plays as the important role in actual welding production.In order to meet these needs, the paper has researched spot welding technology parameters monitor system based on Ethernet, which real time monitor spot welding technology parameters, such as welding current and wielding time, with the function of data acquisition, data disposal, data storage, data display and transmission. This system takes SOC as lower computer to collect and disposal the data of welding current, and electrode voltage, then processing, display and storage those data. It takes portable PC as upper computer, to communicate with lower computer in Ethernet based on TCP/IP protocol, and achieve network online monitor.In the paper, the system takes C8051F020 single-chip microcomputer as the main control unit of the lower computer, which is one kind"Totally Integrated Composite Signal System Level Chip (SOC)", its interior integrated most analog and digital peripheral equipment of control system. The node uses the integrated ADC0 to collect spot welding parameters. The system uses Rogowski current sensor to collect the current signal. The signal adjustment circuit will adjust signals from sensors. After that MCU collects those signals by ADC0 system, and then MCU will count, storage and display those data. To raise a large amount of data acquisition, the system also uses IS62LV1024LL external RAM for mass data storage. As intelligent collection terminal, the lower computer sends collected data to upper computer through the Ethernet bus.The function of resistance spot welding are general, and can be used in resistance spot welding technology parameters monitor of many fields such as car production and aviation. This system have many advantages such as high gathering speed, high gathering efficiency, big memory capacitance and good human-computer interaction interface. It can be used in many high efficiency data acquisition application, and it has high useful value and development foreground.
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