单CCD相机的双光路温度测量方法

A temperature measuring method with a dual optical paths structure based on CCD cameras

为提高双色法测温的精度,我们设计了一种使用中心波长为637nm和541nm的窄带通单色滤波片的双光路光学结构,并通过补偿算法,消除CCD图像传感器在采样中RGB三色宽采样峰交叠对测量的影响.分析了双色测温的原理和补偿算法,设计和搭建了双光路采样光学结构,通过黑体炉对温度进行标定并优化了CCD相机的白平衡和曝光时间设置.对黑体炉的温度测量结果表明,使用本设计的双光路光学结构以及补偿算法后温度最大相对误差为0.48%,而传统双色测温实验的最大相对误差为2.18%,本设计和改进对温度测量的准确度提高了一个数量级.

To improve the temperature measurement of the two-colored method,a dual optical paths structure with two narrow band-pass monochrome filters was designed.A compensation algorithm was proposed to eliminate the overlap of the RGB sampling peaks with CCD image sensors.The principle of the two-colored method,the structure of the dual optical paths and the compensation algorithm were discussed respectively.The temperature was calibrated through a blackbody furnace;and the white balance and exposure time settings of the CCD camera were optimized.The temperatures of the blackbody furnace were measured with the dual optical paths method and the traditional two-colored method respectively.The maximum error of the traditional system was 2.18%,while the error of the dual optical paths method combining with the compensation algorithm dropped to 0.48%.The results showed that the prosposed design improves the measurement accurcy 10 times.