Real-time Monitoring System For Spot Welding Parameters In Welding Workshop

Spot welding machine is largely used in railway coach manufacturers, carmanufacturers and auto parts factory. Suspended Spot-welding machines are largely used inautomobile and fittings factories. The welding quality of each welding spot directly affectsthe quality of the final product. Spot welding machines in factory have been used anddebugging for a long time, they are very reliable and mature. The main the key factorsaffecting the welding quality is the working condition of spot welding machine components.Cable of spot welding machine is easily damaged in the long-term work. When the cablewire is breaking, it is not easy to be found because of the hose package outside. It can befound only if all cable has been broken to find no welding current, which has been damaged,At this moment, the welding current has decreased, which affecting the quality of theproducts. In addition, the voltage fluctuation electrode pressure instability, also affect thequality of welding.Real-time monitoring system of low price is added by not to replace the original spotwelding controller to monitor the welding parameters including welding current, weldingvoltage electrode pressure and timely and effectively display data,through taking thealgorithm and judging rationally aimed at suspension spot welding machine using constantcurrent controller, Real-time monitoring system for spot welding parameters also hascommunication function with the host (server).So, all the welding machines in workshopcan be monitored by one or more server to realize monitoring all the welding machines inworkshop with one computer,enhancing the welding quality substantially.Through the analysis of characteristic of spot welding constant current controller andthe AC resistance spot welding parameters. Develop a set of scheme about monitoringwelding cable damage, welding current, electrode force and welding parameters. Accordingto the scheme, design the hardware circuit of the real-time monitoring system. Determinethe extent of damage to cable through the calculation of welding cable resistance change,monitor welding current, electrode pressure by the internal ADC microcontroller. Collect welding current using the Rogowski coil and an integrator. Collect voltage of cablesdirectly, through isolation module to realize the electrical isolation between the machineand the monitoring system, Collect the welding pressure by gas pressure sensor.In this paper, ATMEGA128is used as the control unit of the lower computer. Thelower computer includes sensor, signal conditioning circuit, microcontroller, external RAM,alarm circuit, program download circuit and serial transceiver circuit. Signal conditioningcircuit mainly includes the isolation circuit, filter circuit, integrated circuit, the ratio of thecircuit, the precision rectifier circuit. This paper chooses ICCAVR as the programmingenvironment, Develops software program for real-time monitoring system for spot weldingparameter in workshop. Draw software flow chart, make modular design of the programand make rational use of resources of SCM. to realize monitor welding parametersaccurately Because of the special nature of the industry environment, Discuss the existenceof interference source, Put forward the reasonable anti-interference measures from twoaspects of hardware and software.Real-time monitoring system with ATMEGA128as the core expanding external RAMcan collect186points for each cycle of AC, It can realize the network monitoring ofwelding workshop through the communication with PC computer, by he reasonablearrangement of single-chip internal resources, through the mathematical operation andreasonable judgement of welding parameter in welding gap time of each welding joint.