可变环境光照条件下的结构光条纹检测

Structured light stripe detection under variable ambient light

线结构光条纹在复杂光照条件下的快速检测是线结构光测量可以实际用于工业现场环境的一个关键技术。针对工业现场环境中光照变化范围大的特点,研究了结构光条纹中心的快速检测方法。首先基于结构光条纹的几何特性自动获取包含结构光条纹的感兴趣区域;然后采用嵌入置信度的边缘检测方法在感兴趣区域内检测结构光条纹边缘;在此基础上,利用结构光条纹边缘反向平行的特性,自动提取结构光条纹中心点;通过对条纹中心点进行直线跟踪得到表示结构光条纹直线段;最终基于直线段确定结构光条纹与被测件的交点以实现自动测量。工业现场采集的结构光条纹图像检测结果表明,该方法可以快速检测不同光照环境下的线结构光条纹中心以及条纹与被测钢板的交点。系统经标定后,实验结果表明在钢板长度变化范围为8～14 m的情况下,基于该条纹中心检测方法的自动测量结果与人工测量结果的标准偏差为3.6 mm。该方法实现了工业现场环境下的实时测量,测量精度满足实用要求。

Fast detection of line structured light stripe in variable ambient light is a key technique with which structured light measurement system can be used practically in manufacture industry. This paper studies the fast detection meth- od of structured light stripe. First, the region of interest that contains the structured light is detected automatically utilizing the characteristic of structured light. Second, the edge detection method that embeds confidence is used to detect the edge of the structured light. Third, the center point of the structured light is extracted utilizing the fact that light stripe has two anti-paralleled edge. The center points are then linked with line tracing algorithm to identify the intersection point between the detected industry part and structured light stripe. Experimental results demonstrate that the method can detect structured light stripe reliably with high speed. After the system is calibrated, the experimental results show in the case that the steel plate length ranges from 8 m to 14 m, the standard deviation between the measurement result obtained using the proposed stripe extraction method and the measurement result obtained manually is 3.6 mm. The proposed structured light detection method can be used in manufacture industry practically.