The Research On Improving Measurement Precision Of Humidity Sensor Based On Data Fusion Technology

Humidity measurement and control of human daily life, industrial production, weather forecast, material storage and so on all play a very important role. The measurement and control of humidity is mainly done through humidity sensor. In order to increase the humidity measurement and control precision and accuracy, the measurement accuracy requirement on the humidity sensor is higher and higher.The main factors affecting measuring precision of humidity sensor is temperature and atmospheric pressure. In addition, electronic humidity sensor, because of the influence of dust, dirt and harmful gas, will produce aging; bring down the accuracy of measurement. The temperature indicator of humidity sensor is easy to measure, but the other indicators are difficult to measure, or even if it can be measured, its accuracy is difficult to meet the needs of humidity measurement system for measuring factor to compensate, so that only the temperature compensation factor can be used for humidity sensor measuring system. In order to meet the requirements of industrial and agricultural development to the humidity sensor accuracy requirements, must be not to increase the compensation factors expect for temperature, take effective data fusion method, as much as possible to improve the measurement accuracy of the humidity sensor.In this paper, the humidity measuring system works in a limited workplace, where the atmospheric pressure and the amount of dust remains in a unchanged conditions,so we first run the curve fitting method to compensation the factors of atmospheric pressure, the amount of dust and other factors. And then using the corrected value of the output voltage of the humidity sensor, the output voltage of the temperature sensor and humidity value establish the humidity sensor support vector machine (SVM) inverse model of the moisture sensor system for temperature compensation. So you can achieve a humidity sensors humidity measurement system for compensation of temperature, atmospheric pressure, and other factors. The system through put the measured humidity sensor output voltage value into a curve fitting equation to compensation for humidity sensor measurement system except temperature; Then put the corrected humidity sensor output voltage value and temperature sensor voltage output values into support vector machine (SVM) temperature compensation reverse model, and then achieve the temperature compensation for humidity sensor measurement system. The system is provided with the key circuit, which can be determined the measurement pattern according to different keys. And the LCD display circuit dynamically displays the measured humidity and temperature values.The experiments show that the measurement system is not only the real-time accurate measurement of environmental humidity value,and stable operation, has the very high practical value.