Research And Development Of High-precision Infrared Leaf Temperature Measurement System

With the development of precision agriculture, in the growth of plants and crops, how to rapidly and accurately monitor the temperature of plant leaf or plant canopy, in order to study the farmland evapotranspiration, irrigation, variety breeding and production forecast, has become a focal point in the development of modern agriculture.For the current plant leaf temperature measurement is not accurate, the operation is complex, time-consuming and so on, this thesis developed a high precision infrared leaf temperature measuring system. Firstly, this thesis designed the hardware circuit of system including temperature measurement module, clock module, storage module and display module, realized the infrared temperature measurement sensor drivers and the software design of each module. Then this thesis proposed a method for accurately measuring the emissivity of plant leaves, proposed a compensation method for improving the accuracy of infrared temperature measurement. Finally this thesis tested the function of system and carried out to verify the compensation effect.This design has completed the high precision infrared leaf temperature measurement system based on MSP430F249 single chip microcomputer, the non contact measurement of plant leaf temperature was realized by using MLX90614 DCI infrared sensor,and the real time temperature data is stored and displayed, quickly and easily completed the leaf temperature monitoring. High precision is another feature of the system, this paper made a theoretical analysis ofthe factors that affect the accuracy of temperature measurement system, including the leaf emissivity, environmental factors andmeasuring distance,and the experimental results showed that the emission rate and measuring distance were the factors that affected the precision of the system, and put forward the errorcompensation formula through experiments, the temperature measurement precision is between ±0.1?, the accuracy is higher than most of the existing temperaturemeasuring equipment. It can meet the requirement of measuring accuracy of leaf temperature in the modern agricultural development.