Output Test Analysis And Synthesis Compensation Research Of Double H Type Silicon Resonant Pressure Sensor

The high-precision pressure sensor is a very critical core component in the field of modern aerospace,and it is also an important guarantee for the spacecraft atmospheric data detection system to accurately detect the pressure.Due to the advantages of small size,light weight,high precision,dual-frequency self-compensating output and strong anti-interference ability,the development of dual-H-type silicon resonant pressure sensor has received extensive attention in the field of pressure sensing.Compared with traditional pressure sensors such as vibrating cylinder type(resonant cylinder type)and single beam resonant type,the double "H" type silicon resonant pressure sensor has significant advantages in weight,volume and precision,but there are differences in the output mode.So it is necessary to design a new sensor signal acquisition circuit.The replacement of the existing sensor signal acquisition circuit will not only cause a waste of resources but also high cost.Therefore,the replacement of new and old pressure sensor in situ has become an urgent problem to solve.First of all,based on the theoretical basis of pressure sensor to detect atmospheric pressure,this paper proposes a dual-frequency synchronous acquisition method and a dual-frequency synthesis method(digital-frequency conversion)based on GD32 microcontroller timer counting and interrupt timing technology.The source of the theoretical error of the dualfrequency synthesis method is analyzed,and an error compensation scheme is designed to reduce the maximum theoretical error of dual-frequency synthesis from 51.15 Pa to 0.1279 Pa.Then,this paper designed a double "H" type silicon resonant pressure sensor for the sensor calibration and verification system.The system designs dual-frequency acquisition and serial port output circuits and programs,dual-frequency data reading and saving software for sensors,and dual-frequency data calibration and verification software.Through two experimental tests of calibration and verification of multiple sensors,various performance parameters such as sensor coefficient and sensor measurement accuracy are obtained finally.Finally,a dual-frequency acquisition and synthesis system for dual-H type silicon resonant pressure sensor is developed by combining dual-frequency synchronous acquisition method and dual-frequency synthesis method.The system uses double "H" type silicon resonant pressure sensor as dual frequency signal source,builds GD32F405RGT6 MCU digital circuit,realizes dual-frequency 20 ms synchronous acquisition while simultaneously outputting a square wave signal.The frequency of square wave signal changes with atmospheric pressure.The system designs the functions of filtering,shaping,isolation and protecting circuit for the input and output signals.The on-line monitoring results under different temperature and atmospheric pressure conditions show that the system can work normally under the atmospheric environment of-45?+85? and atmospheric pressure of 2?266k Pa.The output single frequency range is 4?10k Hz.The errors of dual-frequency acquisition and synthesis are all less than 0.005%of the sensor measurement range.The system is small in size and can be integrated into the circuit of double "H" type silicon resonant pressure sensor,which satisfies the requirements of double frequency acquisition and synthesis output of silicon resonant pressure sensor for atmospheric pressure detection and monitoring.