Today`s machines produce paper so rapidly that visual quality control is stretched to its limits. New automated systems with cameras and image analysis algorithms manage this flood of paper with no problem - they can even tackle the job with patterned wood and textiles.
The fastest papermaking machine in the world produces a roll of paper approximately 10 meters wide at the rate of 100 kilometers per hour. In less than 20 seconds the paper would cover an area the size of a soccer field. Impossible to visually inspect such a flood of paper for flaws. In fact, the slower pace of traditional quality controls using trained personnel often leads to a bottleneck in the entire production process. Automated image analysis systems can perform the task considerably faster and, moreover, the data they gather can be fed back directly to control the production process. The Fraunhofer Institute for Industrial Mathematics ITWM has developed a quality control system known as SPOT. It is capable of checking two and half meters of paper per second, using one camera for every meter of its width. The system identifies imperfections in paper such as glossy patches, scratches, perforations and indentations less than one millimeter in size. A further advantage of the system is that SPOT can be operated using standard PCs and expanded modularly as required.
"The hardware components are only one aspect of the system," explains IT specialist Markus Rauhut. "The attainable speed and precision of quality control depend, above all, on the algorithms of the image processor." The edges of the paper must first be identified, so that they are not registered as flaws. Then, it is important to distinguish essential image contents from nonessential and separate them. Otherwise, with such a huge quantity of paper, the amount of data gathered would be simply overwhelming. Various electronic filters extract typical flaws, which are then reproduced in a new image as "regions of interest". What constitutes a flaw and its permissible dimensions is defined at the start. This reduced-data image can be viewed immediately or be analyzed statistically as part of a defect report. Finally, individual sheets of paper can be automatically sorted and segregated on the basis of their quality.
Dr. Johannes Ehrlenspiel | alphagalileo
Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT
A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
25.07.2017 | Physics and Astronomy
25.07.2017 | Earth Sciences
25.07.2017 | Life Sciences