The Research And Design Of PCR Instrument Temperature Control System

Gene amplification instrument (PCR) in the scientific research and clinical gene amplification has important effect. It is the important basic equipment in the field of life science. Because of comparing to foreign relatively, our country products gene amplification instrument need high production cost and in some key performance indicators such as temperature rise of a number and control accuracy are not as good as abroad products. So the high precision and low cost gene amplification instrument has more important racial significance. In order to improve the gene amplification meter price, this paper made several works as the following:The hardware adopted the STM32core control chip. The temperature sensor of platinum resistance placed the needed detect liquid. Then it will pass over temperature signal into voltage signal which process convenient. Then put it into the STM32through the amplification outputing different wave forms. With its built-in PWM output can achieve directly control on the drive circuit. Realize the semiconductor heating and refrigeration control by drive.Software research for PCR instrument is appropriate for temperature control algorithm. In consideration of PCR instrument have high requirements of temperature rise or drop rate and precision.The design uses the fuzzy self-tuning PID control. The adopt control method in this paper is combined fuzzy control with the traditional PID control. Through adopt the arithmetic of fuzzy self-tuning PID and using MATLAB software to the simulation and verification which fully reflects its superiority.Through the above improvement of software and hardware, according to the working principle of PCR, realize the temperature rise or drop rate and precision requirements.Making the system has a good performance.