焊接视觉图像质心算法及其特性

从焊接视觉图像质心计算公式出发,根据图像灰度与视觉传感器响应电压值的关系、响应电压值与检测部位的发射率及光谱辐射强度等关系,由熔池特性,推导并建立了焊接视觉图像质心与焊接区各点温度间关系模型.通过焊接温度场的数值化,得到图像质心与焊缝中心关系模型的数值解及关系曲线,证明了视觉图像质心与焊缝中心存在相关性,为基于图像质心的焊缝跟踪算法提供理论依据.分析了质心算法的特性,为进一步研究实时焊接图像的质心及算法打下理论基础.

Arithmetic of welding visual image centroid and its characteristics

Arithmetic of welding visual image centroid is studied to detect weld seam center indirectly by calculating centroid of welding visual image obtained from welding visual system in real-time welding instead of direct image processing.From several equations including the relation of response voltage of CCD(charge coupled device) and welding temperature field,wavelength of a narrow-band filter,optical parameters,emissivity of workpieces' surface and weld seam,radiant intensity and so on,the law of Max Planck,the equation between the response voltage of CCD and the gray value of welding visual image and the formula of welding visual image centroid,the model indicating the relation between centroid of welding visual image and temperature of welding pool and heat affected zone has been deduced.The model reveals the relation between the centroid of welding visual image and weld seam center.The tendency of centroid changing with weld seam center has been shown by diagram after welding temperature field simulated.The characteristics of centroid model wone analysed.The centroid of welding visual image has been a closely relevant with weld seam center,which make the application of centroid of welding visual image more reasonable and promising in welding seam tracking.