基于VI的疲劳裂纹在线监测摄像头自动聚焦系统

Camera automatic focus system of on-line fatigue crack propagation monitor based on VI technology

为提高疲劳裂纹在线检测的效率和精度,提出了一种基于视觉识别(VI)的疲劳裂纹在线监测摄像头自动聚焦的方法。该系统主要包括CCD摄像机、镜头、摄像头云台、NI-PCI运动控制卡、光源照明系统、图像采集卡、计算机以及安装在计算机内的图像处理软件和上位机运动控制软件;利用虚拟仪器技术根据摄像头在图像采集过程中的动作要求,设计了一套运动控制方案,进行了基于LabVIEW图像处理自动聚焦技术的研究,并着重研究了清晰图评价函数的选择和寻优算法的设计;最后,对系统进行了软、硬件的调试。调试结果表明,该系统达到了预期的功能需求和精度要求。

In order to improve the efficiency and accuracy of the fatigue cracks on-line detection,a camera automatic focus system of the on-line fatigue crack propagation test based on visual identity（VI） technology was supplied. The system included CCD cameras, lenses, camera PTZ, NI-PCI motion control card, a lighting system, image acquisition card, computer and installation of the image processing software and PC motion control software. In accordance with the camera movement requirements during the image acquisition, the motion control structure was designed, the technology of automatic focus that based on image processing developed by LabVIEW platform was carefully studied, and the key focused was put on the research of the choice of the clear figure evaluation function and the design of the optimum algorithms. The software and hardware of the system were debugged. The experimental results show that this system achieves the expected function demand and accurate request.