Development Of Monitor Intellectualized By IDRC Modeling For Resistance Spot Welding

Resistance spot welding is one of the most important mechanical processes. Itis extensively used in modern industry, especially in automotive and aviationindustry for its high productivity, low cost and high-automation. With thetechnology developing, the request for the welding quality and reliability isincreasing. Recently, many experts in the world have study on the spot weldingquality supervise and control technique for long time. Along with the developmentof the microcomputer technique and intelligence control and many modes controlapplication in the field of the spot welding quality supervise and control, thecontrol mode has been developing from single control mode into a higher level.On the basis of much information integration monitor technique principle andthe study about the IDRC method, this paper develop a new spot welding controlsystem what is named the IDRC intelligent resistance spot welding monitor,through upgrading the hardware system of the IDRC method, optimizing thesampling circuit, enhancing the control system's reliability. This system canharmoniously unify the controlling method, mechanism and object. While, Forenhancing the reliability of the IDRC intelligent resistance spot welding monitorusing in the worksite where have a lot of random interference, the high qualityresume system has been advanced by means of the AT mega8 single chip computer.This system can quickly diagnose and treat with the phenomenon of the programrunaway or the program dead cycles through the intellectualized management forthe user program. So, it can enhance the reliability of the IDRC intelligent monitorfor resistance spot welding in the worksite.The main improvements has been advanced in this thesis:(1) The IDRC intelligent resistance spot welding monitor used the new corethat it is the AT mega8 microcontroller. It can not only improve the speed andcontrol effect of the monitor, but also enhance the sampling precision andintegration of the control system. The development of the IDRC intelligentresistance spot welding monitor is base on the DRC intelligent resistance spotwelding monitor. The DRC intelligent resistance spot welding monitor's core is theMCS-51 microcontroller, while the IDRC intelligent resistance spot of the controlsystem's core is the AT mega8 microcontroller. The AT mega8 microcontroller ismore speed than the MCS-51 microcontroller to two times.(2) On the basis of the AT mega8 microcontroller's characteristic, this paperdesigned the hardware of the control system. The sampling accuracy of the controlsystem is improved through improving and optimizing the voltage synchronouscircuit and the current sampling circuit. While, the hardware mainly consists of thewatchdog and switch resetting circuit, the exactly rectifying circuit, the electrodevalve controlling circuit and the thyristor triggering circuit.(3) The result of the heat function is obtained through using the Dichotomy,and the result is sent to the computer according a specific order. So the heat tableabout controlling the welding heat is set up. In fact, the control system can lookupthe corresponding control angle being based upon the heat table. In fact, the controlangle is always transformed to the computer timer's eigenvalue. While the systemcan send the triggering pulse to the thyristors through the timer's interrupt requestbeing responded. So, the heat function's creation and it's result have a strictnessrelationship with the heat controlling, and it cam improve the control accuracy andeffect of heating process.(4) A means is advanced for the quick diagnosing and treating with therunaway of microcomputer control system through the tactic of the modularizationand close management for the user program. And then, it can exactly find out theprogram entrance and resume all the data which same to it before runaway throughexerting the resume program. Finally, this means can resume the runaway programto the natural state. So it can enhance the system's reliability much.The experiment results illustration: for effectively preventing runaway, thispaper advance the modularization and close management for the user program canquickly find and effective interdiction all kinds of runaway in the program, throughenregistering in the program entrance and mulriple checkup. Through copying theimportant information in the natural state, the recovery program can exactly findout the program entrance and resume all the importance data, and farther it canresume the program to the natural state. So it can effectively prevent themicrocomputer to re-runaway through undoing the chaos of the data memory andPC. It is a effective means that can assure the system reliability work.(5) this paper made the high-quality-recovery system be introduced intothe spot welding control system that is based on the characteristic of the resistancespot welding. The IDRC intelligent resistance spot welding monitor adopt eightsteps, that it have three steps to heating; and then the system also use three interruptprograms to control the process of the welding. This paper use the different meansto manage the program in according of the program's step's difference; while theprogram of the management has been modified in according of the characteristic ofthe interrupt program. Finally the program is fit for the characteristic of theresistance welding.The AT mega8 microcontroller can effectively preventing the program in errorreading the instruction; and then, it has more plenty resource that making the...