多光谱多点标定的CCD二维温度场重建方法的研究

摘要

以多光谱技术作为基础,针对CCD二维温度场测量的特点,提出了彩色CCD二维温度场多光谱真温在线多点标定系统.通过对多光谱辐射测温理论和CCD的测量模型的分析,推导出气体燃烧时的真温与CCD亮度之间的近似关系.使用多光谱多点测温技术计算出多点的发射率和真温并使用这些真温值完成CCD面阵上与之对应点的真温标定.将该真温标定系统应用于CO2激光焊接火焰的二维温度场测量过程中,不但得到了波长与光谱发射率之间的变化规律同时也得到了CO2激光焊接火焰的二维真温分布图.研究提出的多光谱标定技术具有实时性、灵活性的特点,是一种可行的CCD在线真温多点标定与测量的方法.%Based on the multi-spectral technology and the characteristics of CCD two-dimensional temperature field measurement,this paper proposes a colorful CCD two-dimensional temperature field multi-spectral true temperature online multi-point calibration system.With the analysis of multi-spectral measurement model and CCD measurement model,the approximate relation between the true temperature and the brightness of CCD is deduced during the gas combustion.With multi-spectral multi-points temperature measurement technology,the true temperature to calculate the emissivity and the true temperature of multi-points and use values of the true temperature,the corresponding points of CCD array can be calibrated.Applying the two-dimensional temperature field true temperature calibration system in CO2 laser welding flame,we not only get the variation between the emissivity and the wavelength but also two-dimensi onal true temperature distribution maps of flame of CO2 laser welding.Multi-spectral calibration technology has the feature of real time and flexible and is a really feasible temperature CCD online multi-points calibration and measurement method.