高精度红外热成像测温技术研究

Study on high accuracy temperature measurement technology of infrared thermal imager

红外热成像测温系统由于其远距离、非接触、多目标、高精度的特点,发展非常迅速。在当前新型冠状病毒流行的时期,为快速、高效地筛查出高温人群,及时防控、隔离疫情,红外热成像测温技术凸显了其重要性。测量过程中被测物体温度、环境温度、大气温度、镜头温度、探测器温度等因素,对测温精度都有一定影响,尤其是测温曲线的高精度标定对于红外热像仪测温精度影响最为关键。对红外测温原理进行了研究,建立了红外测温系统输出灰度值与被测物体测量温度的匹配模型,找到一种精确标定测温曲线的方法,提出了应用于高精度测温的V-Tr4曲线,以及应用于温漂补偿的V-TFPA、V-T镜筒和V-T快门曲线。经过实验验证,达到了理想的效果,使得测温精度显著提升,测温精度可以达到0.15 K以内。

Infrared thermal imaging temperature measurement system has developed rapidly due to its characteristics of long distance, non-contact, multi-target and high accuracy. In current epidemic period of 2019-novel coronavirus(COVID-19), infrared thermal imaging temperature measurement technology highlights its importance in order to quickly and efficiently screen out high-temperature population, prevent and control epidemic situation in time. During the measurement process, the temperature of the measured object, ambient temperature, atmospheric temperature, lens temperature, detector temperature and other factors have certain influence on the temperature measurement accuracy, especially the high-accuracy calibration of the temperature measurement curve has the most critical influence on the temperature measurement accuracy of the infrared thermal imager. In this paper, the principle of infrared temperature measurement is studied, a matching model between the output gray value of the infrared temperature measurement system and the measured temperature of the measured object is established, and a method for accurately calibrating temperature measurement curves is found. The V-Tr4 curves applied to high-accuracy temperature measurement and the V-TFPA,V-Tlens and V-Tshutter curves applied to temperature drift compensation are proposed. Through experiment verification, the ideal effects were achieved, and the temperature measurement accuracy is significantly improved, which can reach within 0.15 K.