Design And Implementation Of Temperature Control System For Meteorological Microwave Radiometer

Temperature is one of the important factors affecting the stability and measurement accuracy of meteorological microwave radiometer.Based on the practical application engineering requirements,this paper developed a thermostat controller to control the temperature of the receiver of meteorological microwave radiometer.The research content mainly includes The design and debugging of the temperature measurement circuit and the temperature control circuit of the constant temperature control system,the design,construction and testing of the constant temperature structure have been successfully used in the receiving front end of the radiometer,which improves the accuracy and stability of the radiometer measurement system.Compared with the traditional temperature control system,the thermostat controller studied in this paper has the advantages of less complexity and higher precision.The paper mainly completes the following aspects:In the aspect of constant temperature structure design,the working characteristics of the semiconductor refrigeration chip and its optimal working state were analyzed.The related heat dissipation methods were introduced,and the differences of various heat insulating materials were compared.Finally,the copper plate was selected as the heat conductive material,aluminum cover and glass wool.It is an insulating material,and the structure is tested and improved;The temperature control algorithm of the system adopts the PID control algorithm.Based on the detailed description of the principle of PID control algorithm and parameter tuning,the improved PID algorithm is discussed.In addition,the interference suppression of the system is introduced and the corresponding solutions are proposed;In terms of system hardware design,comparing the performance of various temperature sensors,based on the actual engineering requirements of accuracy and temperature range,this paper chooses platinum resistance PT-1000 as the temperature sensor of the system.The AD sampling chip uses the integrated chip LTC2983 to introduce its sampling process and related register configuration.The FPGA control chip EP4CE6E2217 N is selected as the main control chip of the temperature control circuit.The PID control output is loaded onto the drive circuit to control the TEC.By analyzing the advantages and disadvantages of the H-bridge and the relay,two relays are selected as the drive switch to realize the drive circuit design.Finally,the system was tested with a radiometer.The actual test effect is: when the temperature of the space point changes by 10 degrees and the temperature is controlled by 50 degrees,the root mean square value of the temperature of the temperature control point is 0.0090,and the peak-to-peak value is 0.06 degrees.When the radiometer is working stably,the output voltage of each channel changes only by a few ten millivolts.It can be seen that the temperature controller significantly improves the temperature drift of the radiometer and improves the stability of the operation of the radiometer.