滚动轮胎表面红外成像测温的偏差及其修正  

Deviation Analysis and Correction in Rolling Tire Surface Infrared Imaging Temperature Measurement

作　　者：黄梦溪 李子然[1] 夏源明[1] 

机构地区：[1]中国科学技术大学近代力学系、中科院材料力学行为和设计重点实验室,安徽合肥230027

出　　处：《实验力学》2013年第5期595-600,共6页Journal of Experimental Mechanics

摘　　要：使用红外热像仪从三个方向测量了滚动轮胎的表面温度,结果表明从不同方向对同一表面的测温结果不相同。根据几何光学和热辐射原理,造成这一偏差有两个原因:一是轮胎表面点的像面照度按其辐射入射角α的余弦四次方定律变化;二是轮胎表面点的发射率与β(该点入射方向与其法向之间的夹角)有关。本文首先采用余弦四次方定律对三个方向下的轮胎表面红外测试结果进行了与α相关的修正,然后依据轮胎表面任意点温度的同一性(即与测量方向无关)进行了与β相关的进一步修正,并给出了一个轮胎表面发射率与β的经验关系。具体表现为发射率在法向上最大,当β在60°以内时其变化相对平缓,超过60°则急剧下降,最终得到了一个表征轮胎表面点红外像面照度下降的双角度(α和β)修正函数以及相应的温度修正公式。修正后不同方向下的温度分布趋于一致,其平均结果即可视为轮胎表面真实的温度分布。Rolling tire surface temperature distribution was measured from three directions by using an infrared thermal imager. Results show that the measured temperature values of same surface from different directions are different. According to geometric optics and principle of thermal radiation, there are two reasons causing this deviation. The first is that the image plane illuminance of tire surface changes in accordance with fourth power law of cosine of radiation incidence angle a. The second is that the directional emissivity of tire surface, which indicates the emissivity of surface point is related to angle β （the angle between incidence direction and the normal at same point）. Infrared measurement results of tire surface from three directions were corrected （related to a） first, by using fourth power law of cosine. Then, according to temperature identity at an arbitrary surface point （no relation with measurement direction）, the measurement results were further corrected （related toβ）, and an empirical relation between tire surface emissivity and β was derived. The specific performance is that the maximum emissivity is in the normal direction, and emissivity declines gently whenβ is less than 60°, while declines sharply when β exceeds 60°. Finally, a dual-angle （α and β） correction function describing illumination falloff at the tire surface point and corresponding temperature correction equation were obtained. After above-mentioned correction, the measured temperatures from different directions for the same tire surface converge, and the average corrected temperature can be regarded as the real temperature distribution of rolling tire surface.

关 键 词：余弦四次方定律 发射率方向性 红外热像仪 像面照度下降 滚动轮胎 温度修正 

分 类 号：TQ330.38[化学工程—橡胶工业] TB302.3[一般工业技术—材料科学与工程]