复杂产品内部结构装配正确性X射线自动检测系统的研究

Development of X-Ray Digital Radiography Automatic Inspection System for Testing the Interior Structure of Complex Product

为了解决无损检测领域内结构体快速识别的问题,综合多目视觉检测技术与CT检测思想,研究了一种基于单相机的X射线在线自动检测某复杂机械产品内部结构装配正确性的系统,并将其应用于实际生产检测线。采用硬件三点定位与局部区域积分投影求后向差分极值点相结合的方法实现目标的快速定位;提取产品全方位序列图像的分层面混合投影主分量熵作为识别特征;采用BP神经网络的并行运算能力实现对产品的快速分类识别。除上下料外,检测过程全部实现了计算机自动控制。大量实测统计表明,系统误判率≤4.5%,无漏判,平均检测速度小于5 s.

The X-ray digital radiography automatic inspection system with single camera has been developed and successfully applied to the online automated test of some products containing complicated assembly structures by comprehensively considering multiple visual inspection technique and CT in order to solve the issue of nondestructive test of interior structures. First, a method, which uses the 3-point location of hardware and the integral projection of local area to find out a backward differential extremum, locates the product quickly. Second, the principal component entropy of the whole-orientation hierarchical hybrid projection of the ordered image set was extracted as the recognition feature basis. Finally, a BP neural network system was used to speed up the recognition process with parallel operations. The test process was automatically controlled by computer except loading and unloading. The experimental results show that wrong inspection ratio is less than 4.5% without missing inspection, and the average recognition takes less than 5s in test progress.