Optimization And Realization Of Temperature Control System For Laser Crystal Based On Self-tuning Fuzzy-PID Parameter

Temperature control for laser crystal is a research hotspot in laser technology.The instability of crystal operating temperature will seriously affect the output wavelength,output power and service life of the laser.Therefore,in order to guarantee the laser crystal can work with high stability of environment temperature environment,and play a more imporetant role in science and application,this thesis aims at improving the precision and stability of the temperature control system,speeding up the temperature response,reducing system costs,and through theoretical and experimental analyses and comparisions on the traditional analog PID,the traditional digital PID and Fuzzy control,this thesis proposes an optimization design of parameters self-tuning Fuzzy-PID high precision.The main contents are as follows:Firstly,on the basis of traditional PID temperature control design,this thesis focuses on the optimizations of the model,temperature acquisition module and control algorithm.The optimal mathematical model of temperature control device of laser crystal is determined by the method of system identification.After studying the application of PID control theory in temperature control system,fuzzy control idea is introduced,fuzzy-PID controller is designed,and system platform is constructed by Matlab Simulink,and online simulation comparison is made for traditional PID and Fuzzy-PID parameter self-tuning control.Secondly,the software and hardware of the control systems are designed.The emphasis is on the optimization of the system.Based on the traditional analog PID control system and the freescale K60 single chip computer as a core controller,we combined fuzzy control theory with traditional digital PID,programed temperature control system with the idea of modularization design,and realized the on-line realtime adjusting of PID parameters.In terms of hardware,temperature sensor(NTC thermistor)and temperature actuator(semiconductor refrigerator TEC)were studied and selected,and whole temperature control circuit was designed,including temperature measurement and control circuit,power supply circuit,TEC drive circuit and communication circuit.In terms of software,the program of temperature control system was written,including interrupt service,temperature collection,digital filtering,Fuzzy-PID temperature control algorithm and communication.At last,the system is made and tested.The experiments show that: the fluctuation of the parameters self-tuning Fuzzy-PID temperature control system control to stabilize fluctuation is less than ±0.005 ? within the range of 10 ? to 60 ? temperature.Compared to traditional analog PID system and the digital PID control system in the temperature control,our system has the advatages of better,heating up fast,small overshoot,high precision and stability,produces the desired effects of and verifies the validity and feasibility of the optimized temperature control.