Research On The Monitoring System For The Parameter Of Resistance Spot Welding Based On Wireless Network

Resistance welding technology has got rapidly developed in recently years, due to theadvantage of its concentration of energy, small deformation, few auxiliary processes, noaddition of filler material, high efficiency and easy to realize automation. Resistance spotwelding is one of the most commonly used resistance welding technology. The process ofresistance welding is a non-linear, multi-variable coupling, complex and dynamic thermalprocess, and it includes large number of random factors process. In order to ensure qualityof welding quality real-time monitoring must be conducted. The signal transmission of thewelding process monitoring system usually use wire transmission, which will bring a lot ofquestions such as wiring difficulties and security risks. And wireless transmissiontechnology would be a good solution to the problem. Moreover, using the wirelesstransmission technology will improve production efficiency greatly, and reduce theproduction cost clearly. Using the wireless transmission to monitor the welding process, thestaff can remotely monitor and control the production systems and welding equipmentoperating parameters safely and comfortably.To meet the demand of the real-time monitor and control of the welding parameters,and taking into account the outstanding advantage of wireless transmission, in this paper thewireless network system based on ZigBee protocol for resistance spot welding productionhas been researched. The system uses MCU as the lower computer, to collect and processthe data of the welding information, such as welding current, welding voltage and electrodepressure information. At the same time, the system uses industrial personal computer as theupper computer, to display and store the parameters transmitted from the lower computer.The wireless communication between the upper and lower computer is complied by ZigBeewireless module. The system has the main functions of the collection processing display,storage and wireless transmission of the parameters in the spot welding process.In this paper, C8051F020MCU is used as the central control unit of the lowercomputer, and combined with current sensors, voltage sensors, pressure sensors, signal conditioning board, external memory and wireless module constitute the lower computer.Keil μVision2is used to conduct to comply the program of the lower computer, to collectprocess and store the welding parameters. The upper computer uses Visual C++to conductthe design of the main program interface, to process and store the data transmitted by thelower computer further. Moreover, the upper computer displays the wave from and weldingtime corresponding to the welding parameters, which will be able to reflect a series ofparameters of the welding scene in real-time.In this paper, the communication between the upper and lower computer wascompleted by JN5148wireless module, which is based on ZigBee PRO technology. ZigBeeis the emerging,short-distant and low-rate wireless communication technology, which hassome advantages of low power, low cost, flexible networking and high reliability. The papermainly researched on the formation of the wireless netwok based on the ZigBee technologyand the design of program for the wireless module; and carried out the wirelesscommunication between the upper and lower computer, then the capabilities of the wirelesswas tested. The result indicates that the capabilities of the wireless communication can meetthe requirement of monitor the welding process in real-time.Compared with the parameters measured by corresponding instruments in fact withthat monitored by this system, it can be seen that the system has high accuracy and goodwaveform display, as well as the good ability to monitor the welding parameters in real time.The system has the advantage of good stability, high accuracy, low cost and easy tomaintain, especially in the harsh factory environments would reflect the advantage of thesystem better. The system can be used in automobile, steamship aerospace and otherindustries’ field, to improve the production efficiency and welding quality of the resistancespot welding. And the system can make the resistance spot welding applied more effectivelyin the actual production.