The Research And Design Of A High-frequency Inductive-bead Maker

The demand of X-pay fluorescence spectrum analysis is that the sample ismelted at the high temperature about 1600℃, at the same time, the sample shouldbe shook up, and the high-frequency inductive-bead maker offers the sample forthe analysis of X-pay fluorescence spectrum. In recent years, the high-frequencyinduction heating technology is a new heating method, which has many advantage,such as heating equably,high heating speed,low power consumption and slightenvironment pollution. The way to offer sample for X-pay fluorescence spectrumanalysis by the high-frequency inductive-bead maker is proved the better way.This dissertation introduces the heating current supply of the high-frequencyinductive-bead maker, the super power silicon controlled rectifier (SCR) is appliedto the full bridge controlled rectifier circuit, while the insulate gate bipolartransistor (IGBT) is employed in the single-phase parallel circuit. The powersetting of high-frequency inductive heating current supply is implemented by thesetting of pilot angleα of silicon control with single chip computer setting. Thisdissertation gives a simulating analysis to the way of temperature control, usefuzzy PID control method to control the high frequency inductive heating device,control the system temperature, so as to meet the sample on output temperature. Atthe same time, this dissertation introduces the water supply pump of thehigh-frequency inductive-bead maker and auto control method of vibrationstructure.The whole dissertation has six chapters;the main contents are as follows:1. IntroductionThis chapter mainly introduces the principle and application of thehigh-frequency inductive-bead maker, which offers the sample with high qualityfor X-pay fluorescence spectrum analysis, it solves many problems of usingresistance furnace to melt and get sample. Compared to resistance furnace to meltand get sample, it can improve production efficiency, decrease the powerconsumption, and reduce the environment pollution and harm of operation crews,is necessary device for overseas X-pay fluorescence spectrum analysis.2. Technical Analysis and Temperature Control PrincipleThis chapter mainly introduces the composition and each part's function ofthe high frequency inductive heating current supply, including parallel resonantcircuit, three-phase silicon control rectifier circuit, and so on.Besides, it introduces several common used control methods, such as PIDcontrol method particularly, fuzzy control method, and fuzzy PID control method.The PID control method includes simulation PID and digital PID control method,this chapter introduces each parameter's function of PID controller and settingmethod. Fuzzy control method mainly introduces the basic of fuzzy control, theconcept of fuzzy mathematics, the principle of fuzzy control and the designmethod of fuzzy controller. It contains several steps which are establishment offuzzifiction and fuzzy control rules, fuzzification reasoning and anti-fuzzification.It introduces the method of fuzzification, the standard of establishing fuzzy controlrules, and the common method of anti-fuzzification. There are several forms offuzzy control method: fuzzy-compound control, proportion-fuzzy-PI control,fuzzy-integration hybrid control, and parameters fuzzy self-setting control. Thispart especially states the parameters setting method based on fuzzificationreasoning.3. Design of Fuzzy PID Controller and Matlab SimulationAccording to the character of this system, position-type PID control method ischosen. Fuzzy controller uses temperature error and the error range as its inputparameters, gains the fuzzy controlled value of PID control coefficient by fuzzyand fuzzification reasoning, and finally gains the accurate value of PID controlcoefficient by anti-fuzzification.It gives a simulating analysis to this system to validate the character of fuzzyPID controller. The mathematics model is established by the controlled member'sanalysis. This chapter obtains its transfer function, and then makes a conclusion bysimulation by PID control method, fuzzy PID control method with softwareMatlab: PID control method has too large overshoot, too long adjustable time, butsmall steady-state error. While the fuzzy PID control method has good dynamicand static performance, few overshoot and short adjustable time, steady-state errorwith closing to zero, better anti-interference ability. At the same time, it analyzesthe effect of coefficients on control character.4. Design of System HardwareThis chapter mainly introduces the system hardware structure, includingperipheral circuit of monolithic computer, AD acquisition card, amplificationcircuit, display circuit, high-frequency inductive heating furnace and other loadcontrol circuit. AD collection chooses twelve bit AD transition card with samplingretaining circuit. The display part is composed of liquid crystal 1602 showingspecified temperature and actual temperature, time relay shows holding time. Thepower setting of high-frequency inductive heating current supply is implementedby the setting of pilot angleα of silicon control with single chip computer setting.What's more, the tamper-proof is an important part of this system;this chaptermainly introduces some specific way of hardware tamper-proof, which has goodeffect.5. Design of System SoftwareThis chapter mainly introduces the design thinking of system software, thedesign of fuzzy PID control software is a central part of whole system. Itintroduces fuzzy control subroutine, PID control subroutine, and digital filtersubroutine and program flow diagram of linearization disposal subroutine.6. ConclusionGive a research conclusion of the whole dissertation, and do experimentsunder available conditions in the lab, the result proves that the system design istotally satisfactory.