Research On Intelligent Detection System Of Diffused Silicon Piezoresistive Pressure Sensor Based On MEMS

With the rapid development of information technology,sensor technology is widely used in all walks of life.Micro pressure sensor is one of the most widely used and far-reaching micro sensors in all fields.Diffused silicon piezoresistive pressure sensors have the advantages of high precision,high sensitivity and fast dynamic response,and are widely used in various industrial measurement and control fields.butThe precision of MEMS diffused silicon piezoresistive pressure sensor is seriously affected by the environment and power supply stability.In this paper,the problems of power supply,zero point drift and temperature drift are deeply studied,so as to design a high-precision intelligent pressure sensor detection system.The main research contents are as follows:1.Power supply stability.In this paper,a high stability constant current source power supply based on MC1403 is designed to effectively suppress common mode interference.2.Zero drift problem:the zero output of the sensor is different at different temperatures.The method of parallel resistance on wheatstone bridge is adopted to reduce the influence of temperature on the bridge.3.Temperature drift problem.The two-dimensional calibration experiment of pressure sensor and temperature sensor was carried out,and the temperature compensation model of fruit fly optimization algorithm optimizes least square support vector machine?FOA-LSSVM?was established.After temperature compensation,the zero temperature coefficient and sensitivity temperature coefficient of the sensor are increased by an order of magnitude,and the temperature compensation effect is obvious.4.In this paper,combined with STM32F767IGT single-chip microcomputer,a high-precision pressure intelligent detection system including system power supply,AD conversion,data processing,WiFi communication,serial communication,LCD display,alarm circuit and other modules is designed to ensure the stable operation of the detection system and high-precision outputThe results show that the constant current source circuit made of MC1403 precision voltage reference source can effectively suppress the common mode interference of the pressure sensor.The method of parallel resistance on wheatstone bridge can effectively reduce the zero drift problem of the pressure sensor.When the least squares support vector machine is used to compensate the pressure sensor,the zero temperature coefficient increases from?₀?28?5.08?10^4-/?to?'₀?28?8.942?10^5-/??that is,it increases by an order of magnitude?.The sensitivity temperature coefficient is increased from?_S?28?2.03?10^-3/?to?'_S?28?2.505?10^-4/??that is,it is increased by an order of magnitude?,so as to improve the temperature stability of the diffused silicon pressure sensor.