Adaptive Compensation Method for the Infrared Temperature Measurement Error Based on 3-D Thermal Imaging

Abstract

Infrared thermal imager can provide two-dimensional temperature information of the measured object on-line without contact, which is one of the most commonly used temperature measurement methods. However, the measuring distance and viewing angle between the thermal imager and the measured object will cause the infrared temperature measurement error. In order to automatically compensate for the temperature measurement error caused by measuring distance and viewing angle when the infrared thermal imager is applied in actual measurement scenarios, this paper proposes an adaptive compensation method for the infrared temperature measurement error based on 3D thermal imaging. Firstly, based on the polynomial regression and infrared temperature measurement principle, a compensation model is established to compensate for the temperature measurement error caused by measuring distance and viewing angle. Secondly, the parameters of the compensation model are determined by using a blackbody furnace and a reference cylinder. Then, a 3D thermal imaging system is constructed with a depth camera and an infrared thermal imager to quantify the measuring distances and viewing angles between all temperature pixels and the thermal imager. Finally, the surface temperature of the measured object can be adaptively compensated using the established compensation model. The experimental results of the blackbody furnace and resin cylinder show that the proposed method can adaptively compensate for the infrared temperature measurement error caused by measuring distance and viewing angle.