Design And Research Of Miniaturized Rainfall Sensors Based On Piezoelectric Effect

Rainfall monitoring is of great significance in meteorological research,water management,transportation and agricultural production.Traditional rain sensors have certain limitations in measurement accuracy and application scenarios,and their main problems include long technology development cycle,high maintenance costs,large volume,and inability to guarantee the authenticity and validity of data in real time.As a result,there is a growing demand for miniaturized,high-precision,and light-maintenance rain sensors.Based on the piezoelectric effect,a new piezoelectric rain sensor is designed,which solves the problems of traditional rain sensors to a certain extent,optimizes the data processing method and improves the measurement accuracy.Firstly,the working principle and application scenarios of different rainfall sensors are analyzed,and a rain detection system based on piezoelectric effect is proposed,which realizes high-precision measurement in different rainfall environments by designing the structure,circuit and algorithm of piezoelectric rainfall sensors.The specific research content is divided into the following aspects:（1）The system design of piezoelectric rain sensor was carried out,and the volume index（maximum diameter is 93 mm）,weight index（350 g）and functional index（measurement range 0 mm～1000 mm,resolution 0.01 mm）were clarified.（2）In terms of structure,PZT-53 piezoelectric ceramic sheet with piezoelectric constant of 550×10^-12m/v is adopted to improve the response speed and measurement range of rain sensor;The housing design has been simplified with an all-in-one design to reduce the weight of the rain sensor and increase its installation flexibility.（3）The circuit design was carried out,aiming at the problem of weak charge signal amplification,the three-op amp differential charge conversion circuit was used to convert the charge into a voltage signal,which could detect the weak charge at the amplified p C level and effectively suppress the common-mode interference.（4）Based on the Generalized Regression Neural Network（GRNN）,a nonlinear regression model of voltage and rainfall output value is established,and the rainfall value is calculated by training and optimizing the model.At the same time,a data fusion method of rainfall,temperature and humidity is established to filter invalid data（abnormal impact data）,and reduce the measurement error of the entire rainfall detection system to 3%.The temperature and humidity reading program,communication transmission program and other modules are designed to realize the real-time collection and transmission of data,and improve the practicality of the system.In order to verify the basic functions of the piezoelectric rainfall sensor,the artificial rainfall simulation system was used to simulate different rainfall environments,and the piezoelectric rain sensor was compared with the tipping bucket rain gauge and Zhongming rain gauge.The experimental results show that under different rainfall intensities,the measurement error of piezoelectric rain sensor is controlled within 3%,which is significantly improved compared with the error of 5%of Zhongming rain gauge.The thesis verifies that the design scheme proposed has high reliability and practicability,which provides strong support for the practical application of piezoelectric rain sensor.