船用造水机常见故障原因及对策

远洋运输船舶上的造水机对于运输的经济效益和航情变化的应对能力具有十分重要的意义。一旦遇到造水机发生故障,不仅影响船员的正常生活,还会危及船舶的运输安全,因此保证造水机正常工作,提供充足的淡水就显得非常必要。文章对造水机常见故障的原因进行了分析,并提出了一些对策措施,对提高航运的经济性和安全性,具有重要意义。     

基于机器视觉的球笼保持架窗口位置检测方法

介绍了一种基于视觉检测技术的球笼保持架窗口位置在线检测方法.采用具有独特双光源照明的成像系统的同时获取了窗口边缘和基准面的图像信息,以VC++为平台对数字图像信息进行处理和分析,频域高斯滤波完成图像去噪后,采用形态学边缘检测算法获得窗口边缘点和基准点,利用两直线的平行关系开展最小二乘直线拟合确定窗口边缘位置.实际应用证明该系统稳定可靠,检测效率高,具有良好的应用前景.     

Modified gray level difference-based thresholding segmentation and its application in X-Ray welding image

Thresholding is a popular image segmentation method that often requires as a preliminary and indispensable stage in the computer aided image process, particularly in the analysis of X-ray welding images. In this paper, a modified gray level difference-based transition region extraction and thresholding algorithm is presented for segmentation of the images that have been corrupted by intensity inhomogeneities or noise. Classical gray level difference algorithm is improved by selective output of the result of the maximum or the minimum of the gray level with the pixels in the surrounding, and multi-structuring of neighborhood window is used to represent the essence of transition region. The proposed algorithm could robustly measure the gray level changes, and accurately extract transition region of an image. Comparisons with other approaches demonstrate the superior performance of the proposed algorithm.     

High Efficiency and Quality of Multi-Pass Tandem Gas Metal Arc Welding for Thick Al 5083 Alloy Plates

Multi-pass tandem gas metal arc welding(TGMAW) for Al 5083 alloy plates with 30 mm thickness is carried out to study its high efficiency and high quality. The welding process is evaluated by high-speed photographs and electrical signals. The deposition rate and welding time are calculated to characterize the welding efficiency. The bead formation, porosity, microstructure and mechanical properties are tested and analyzed. The results indicate that though arc deflection occurs due to the electromagnetic interference between two arcs during TGMAW process, it does not affect the welding process stability significantly. The deposition rate and welding time of TGMAW process are about 15 g/min larger and about 16.7% less than those of gas metal arc welding(GMAW)process respectively, accompanied by the reduction of heat input. The TGMAW welded joint has less porosity and more refined microstructure to contribute to the improvement of mechanical properties(micro-hardness, tensile strength and ductility). It can be concluded that TGMAW process yields excellent performance of welded joint with improved welding efficiency, which makes it extremely practical during welding of thick plates.