Research Of Temperature Control System Based On Semiconductor Refrigeration Technology

Inertial navigation system can positioning independently and provide the attitude and acceleration information of carrier,which making it has an irreplaceable role in the field of aeronautics and astronautics.Because of the gyroscope and accelerometer as the core device of the inertial navigation system sensitively to temperature,temperature drift has become a major errors source.To reduce the influence of temperature on inertial navigation system measurement precision,creating a small space of constant temperature environment used for the test and temperature compensation of gyroscope and accelerometer will be a beneficial attempt.The design of temperature control system based on semiconductor refrigeration technology includs the TEC temperature control hardware system and the LabVIEW temperature monitoring human-computer interaction system.The lower computer collects data of three DS18B20 temperature sensors in real time and snends to the LCD display.According to the difference of actual temperature and target temperature,outputting corresponding digital signal by piecewise PID temperature control algorithm.The digital signal be transformed to controlled current by two DAC module,and then drive the two emiconductor refrigeration module to control the box to attain the target temperature.The upper computer communicates with lower computer through the RS232 serial port,to realize the function of collection,display,drawing,alarm and data storage.During the tests of temperatuer control property and temperature compensation,fristly using the least square method to calibrate the sensors,the maximum average error reduce from 0.465?to 0.075?,the measurement precision increased significantly.Then proceed the reliability and stability testing,and the system run continuously 40 hours without any fault.The results of emperature measurement precision and temperature control effect tests show that the system measurement error is within 0.1?,and the temperature control accuracy basically achieve the design targets of ±0.5?.The system finally used for the temperature compensation test of a certain MEMS nertial navigation module,the overall effect is ideal.