外文翻譯--印刷品質(zhì)量的在線自動檢測方法及系統(tǒng)（原文）

1、Int J Adv Manuf Technol DOI 10.1007/s00170-006-0505-7ORIGINAL ARTICLEHui-Chao Shang . You-Ping Chen .Wen-Yong Yu . Zu-De Zhou Online auto-detection method and system of presswork qualityReceived: 1 September 2005 / Accep

2、ted: 25 October 2005 / Published online: 11 April 2006 # Springer-Verlag London Limited 2006Abstract An online auto-detection method and system of presswork quality is studied in this paper. An evaluation criterion for r

3、eal-time-gathered images of multicolor printing is proposed. Integrated designing and optimizing make it transparent the key factors influencing the real-time performance of a detection algorithm. A subspace-based regist

4、ration algorithm that accelerated the search speed is presented, and the dynamic refreshing of a reference image avoided the cumulative departure and improved the registration precision. To obtain the position and geomet

5、ric characteristics of various defects in real time, a method of thresholding by cluster and line-by-line scanning of a dynamic array is proposed to extract and merge defects. Finally, geometric characteristics and stati

6、stics parameters are adopted to classify and identify the massive defects, discrete dots defects, and linear defects. A motion image acquisition system and distributed computer processing system are designed. Experimenta

7、l study and practical running indicates that defects including stria, splash ink, blowby, foreign bodies, etc. could be detected, displayed, stored, and warned in real time. The detection speed reached 250 m/min and the

8、precision reached 0.375 mm in the running direction and 0.15 mm in the crossing direction.Keywords Online detection . Automatic detection .Presswork quality . Image processing1 IntroductionBy the integration of designing

9、 and processing control information, machine vision systems could obtain vastamounts of information quickly and easily. Therefore, machine vision technology has been receiving a lot of attention recently as an inspection

10、 method, and has been applied in all kinds of industry inspection processes, such as post-bonding [1], defects of steel surfaces [2], fabric inspection [3], fault of water bottles [4], coins detection [5], etc.The online

11、 detection of presswork falls into theapplication of machine vision in the industry detection domain. The custom detection methods to presswork include manual rechecking after presswork, naked-eye observation online, mon

12、itoring through monitor processes and random inspection, etc., and have the disadvantages that include severe waste of rough material, visual fatigue, random inspection unable to guarantee the overall quality, and so on.

13、 With the developing of press technology, the increasing of press speed, and the complexity of data and information, the manual modes of printing quality control have already become unfit for the practice demand of the p

14、ress industry. To guarantee the printing quality of presswork overall and raise the production rate, it is essential to perform real-time online quality detection for presswork.In recent years, the wide application of hi

15、gh-speed CCDindustrial camera technology and high-performance micro- computers have provided better hardware performances for the realizing of real-time online quality detection [6]. The study of high real-time performan

16、ce algorithms and the research of online automatic detection systems to press- work have been presented to cope with the customer demand. The driving force behind these machine vision systems is the 20%–40% reduction in

17、print waste, and the systems allow presses to operate at high speed and also enable package printers to meet the productivity require- ments necessary to ensure lasting customer satisfaction [7].Application-specific mach

18、ine vision systems or videoinspection systems developed for the printing industry, like all machine vision products, capture an image from either an area camera or a linear array. The images are digitized and manipulated

19、 in various ways, depending on the specific niche application(s) that the system is designedH.-C. Shang (*) . Y.-P. Chen . W.-Y. Yu . Z.-D. Zhou Room 107, D8 Engineering Research Center of Numerical Control System, Schoo

20、l of Mechanical Science and Engineering, Huazhong University of Science and Technology, 430074 Wuhan, Hubei, People’s Republic of China e-mail: sh_hc@126.com Tel.: +86-27-8754148233: (2007) 756–765To satisfy this require

21、ment, an optic system that could implement high-speed image acquisition should bedesigned.The optic system of image acquisition is composed of acamera, lens, illumination system, etc. A TR-33 line-scan camera of the DALS

22、A Corporation is adopted in the detection system; the pixel number per line is 2,048 and its line rate is equal to 11 kHz, which fulfils the demands of the image acquisition system for high-speed motion targets. Three hi

23、gh-performance line-scan sensors (3CCD) collect high-quality image information from the prism and passes it to the integrated signal processing circuits, and this allows the camera to adapt to variations in the intensity

24、 and spectra of the utilized light source. The lens adopted in the system is a Nikon 50-mm normal lens, which has the merits of less distortion, high reduction performance, high suitability to various polarizing screens

25、to make it easy to control the direction of the rays entering the lens, and a large aperture, which can fulfill the demand of a high-speed shutter in relation to the light quantity in the conditions of high-speed movemen

26、t.The design of the illumination system is an importantelement of machine vision system design. The illumination system of an acquisition device should ensure that the gathered image has less distortion, less deformation

27、, no apparent color cast, and no reflect halation and glare on one hand, but it should also ensure that the acquired image has florid color, distinct details, uniformity of intensity, etc. on the other hand. By the consi

28、deration of the spectrum, colortemperature range, life, cost, and complexity of different light sources, a fluorescence lamp with a color temperature of 6500 K is adopted in our system.Light path design determines the pe

29、rformance of theillumination system. In the design processing of the light path, the lens view field, distance between the illumination system and the acquisition target, surface condition of the acquisition target, and

30、the imaging objective lens are all elements that need to be considered. In our experiment, the lens’ focal distance is 50 mm, the field angle is 46°, the vertical distance between the light source and presswork is 4

31、0 mm, and the acquisition target is the web color presswork. The light source is mounted in between the camera group and the acquisition target. It has enclosed structure and should be set as near as possible to the acqu

32、isition target so as to make the best effort to suppress the interference of ambient light. At the same time, a high- frequency fluorescence lamp ballast is designed toguarantee that the gathered image has uniform intens

33、ity and no flashing.Figure 2 is a diagrammatic sketch of the enclosed lightsource. Four strip lamps are divided into two eudipleural groups, upper and lower. Part of the light emitted from upper strip lamp exposes on the

34、 presswork surface through the light transmission glass directly; another part exposes on the presswork surface through the light reflection plate indirectly to enhance the luminous intensity. The light emitted from the

35、lower strip lamp cannot expose on the presswork surface directly, but exposes on the presswork surface through the scattered reflection plate. The scattered reflection light could not only enhance the luminous intensity,

36、 but it is also able to soften the light exposed on the presswork surface and eliminate glare. The whole light path forms a linear light source, whose direction is parallel to the axial line of the press roll and whose i

37、lluminated range is a linear area near the middle line of the press roll surface. There is a slit in the top-middle of the light source that is made up by a pair of parallel baffle plates; the image of the illuminated ar

38、ea enters the camera lens through the slit to realize the scan of the presswork image.The setup and position of the camera is an importantelement of the light path design also, and this function isHost computerSlave comp

39、uter 1 Slave computer 2 Camera 2 Camera 1 Photoelectric encoder Light source PressworkAlarm 1 Roll Operating console Alarm 2 Network hub Fig. 1 Structure of the detection system and the relationship between components