A Detecting System Of Spot Welding Current Effective Value Based On MSP430

Resistance spot welding is a welding method used on machining building industry extensively, and on welding process the current is the key parameter. Therefore, in order to engage for welding quality, the high degree of accuracy real-time detection becomes more and more important.In this paper, in allusion to the problem of low accuracy, bad real-time, complexity electric circuit of traditional spot welding current detecting meters, an idea of actualizing the real-time collection and calculation of spot welding current effective value use point-by-point algorithm is put forward, a spot welding current effective value detection system based on MSP430F135 single chip computer is designed, the real-time detection and display of spot welding current effective value and energizing cycle number is come true.Firstly, this paper discusses the point-by-point algorithm, introduces the sensor of system and the key device of hardware circuit, brings forward the system total diagram of miniaturization and product planning, and discusses the working process of system.Secondly, on the base of the system total diagram, this paper introduces the analog circuit, digital circuit, current source circuit and JTAG interface circuit of hardware part in detail. About the most important circuit design of analog part of hardware, this paper introduces its analog simulation process uses software Multisim 2001, and analyses the simulation result in detail, certificates the viability of system design. On the base of the hardware design, this paper introduces the main program, A/D convert subprogram, Timer A abruption subprogram and liquid crystal display subprogram of software systematic. Otherwise, this paper analyses the disturbance element of welding field and the methods of anti-jamming.Finally, in allusion to the current detection system simulation, reliability detection, and the detecting result on the welding filed, this paper analyses their data and curves in detail. The result indicates that the data of this system detected on the welding filed inosculates well with Japanese ammeter MM306-A. The error of cycle number is zero, the biggest proportional error spot welding current effective value is 2.15%, the mean absolute error is about 156A, and these results contentment the demand of real production.The achievements that the thesis makes have certain theory and project practical value for detecting of spot welding current, nationalization of ammeter, and quality controlling of spot-welding process.