Zellulare Neuronale Netzwerke: Pixelparallele Bildverarbeitung zur Regelung von Laserschweißprozessen

Eine echte Regelung schneller industrieller Prozesse scheitert nicht selten an der Bildverarbeitung. Hier müssen über 10 000 Bilder pro Sekunde verarbeitet werden, um Messwerte in Regelsignale umzuwandeln. Mit einer neuen Kameraarchitektur gelingt es, Laserschweißprozesse in Echtzeit zu regeln. Rechen- und Speicherelemente, integriert in die einzelnen Pixel eines Kamerachips, ermöglichen es, Prozessschritte nicht wie üblich sequenziell, sondern parallel auf eine Vielzahl von Daten anzuwenden. Voraussetzung sind Algorithmen, welche die Eigenschaften solcher Zellularen Neuronalen Netzwerke effizient nutzen

Vorrichtung zum beruehrungslosen Erfassen von Abstaenden zu Gegenstaenden

EP 1544572 A UPAB: 20050823 NOVELTY - Contactless measurement device for determining the distance between a railway vehicle and various elements of the permanent way has a reference measurement unit (20) with which one or more distance measurement units (14-17) can be checked by measurement of a distance to a characteristic point on a rail. A correction module is then used to correct other measurements based on the measurement of the distance to the reference point. USE - Contactless measurement device for determining the distance between a railway vehicle and various elements of the permanent way. ADVANTAGE - Distance measurement accuracy is improved

Schnelle Entfernungsmessung für Laserscanner

This contribution describes the principle of distance measurement by means of a modulated laser beam and phase detection. The most critical impacts on accuracy and reliability like noise, modal structure of the laser, and crosstalk are qualified and quantified. Counteractive measures to reduce their influence are shown. The realized distance measuring module enables to measure distances in a some ten meter range with frequencies up to 1 MHz. Some results of a laser scanner for clearance measurement of railway lines are shown

Novel geometry for a high speed outdoor laser scanning system

Today, the phase shifting technique is still the fastest and most accurate measurement method for laser scanners in the meter and some 10 meters range. A major handicap for outdoor applications such as railway measurement systems is the influence of optical cross talk caused by pollution of the optical surfaces. This effect is closely linked to the multi target response of phase shifting systems which is analyzed quantitatively. It is shown that optical cross talk is a major cause for nonlinearities when dark objects are measured. To overcome this disadvantage a sealed cover with light traps was designed for a 350 degree scanner to protect the most critical surface of the scan mirror and to absorb the stray light from the polluted outer surfaces. The sampling rate of this system can be doubled without loss of measurement accuracy by using a new scan geometry with two fibre coupled measurement heads on each end of a hollow scan axis with a double sided scan mirror

High power LED lighting for CNN based image processing at frame rates of 10 kHz

CNN based cameras are able to process images in the kHz range in machine vision systems, as demonstrated for the closed loop control of laser welding processes. Other applications do not benefit from a comparable light source. This paper reports the current state of a LED based lighting for the inspection of cylindrical metallic surfaces on aluminum wires. Frame rates of 10 kHz and exposure times of 20 µs have been achieved so far

A camera based closed loop control system for keyhole welding processes: Algorithm comparison

Real time monitoring of laser welding has a more and more importance in several manufacturing processes ranging from automobile production to precision mechanics. Despite the huge improvement in welding technology, sophisticated image based closed loop control systems have not been integrated in commercially available equipments yet. Due to the high dynamics of laser beam welding (LBW) processes, robust closed loop control systems require fast real time image processing with frame rates in the multi kilo Hertz range. In the last few years, some new high speed Cellular Neural Network (CNN) based algorithms for the full penetration hole detection in keyhole welding processes have been introduced. In particular, they can be distinguished in two categories: Orientation dependent and orientatio n independent algorithms. The former can be used only for the welding of straight lines, while the latter has been implemented for the control of curved weld seams. Both algorithms have been used to build up a real time closed loop control system for LBW processes. An algorithm comparison by the description of some experimental results is addressed in this paper