In the steel industry, laser triangulation based measurement systems can be utilizedfor evaluating the flatness of the steel products. Shapeline is a company in Linköpingthat manufactures such measurement systems. This thesis work will present a series ofexperiments on a Shapeline measurement system in a relatively untested environment, thehot rolling mill at SSAB in Borlänge.The purpose of this work is to evaluate how the conditions at a hot rolling mill affectsthe measurement performance. It has been anticipated that measuring in high temperatureenvironment would introduce difficulties that do not exist when measuring in cold environments.A number of different experiments were conducted, where equipment such as laserand camera bandpass filter were alternated. Via the experiments, information about noisedue to the environment in the hot rolling mill was gained. The most significant noise wascaused by heat shimmering. Using the presented methods, the magnitude and frequencyspectrum of the heat shimmering noise could be determined. The results also indicates thatheat shimmering cause large errors and is quite troublesome to counter. In addition to this,the quality of the line detections under the hot rolling mill circumstances was examined. Itcould be observed that the line detections did not introduce any significant errors despitethe harmful conditions.

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<p>Shape-based matching (SBM) is a method for matching objects in greyscale images. It extracts edges from search images and matches them to a model using a similarity measure. In this thesis we extend SBM to find the tilt and height position of the object in addition to the z-plane rotation and x-y-position. The search is conducted using a scale pyramid to improve the search speed. A 3D matching can be done for small tilt angles by using SBM on height data and extending it with additional steps to calculate the tilt of the object. The full pose is useful for picking objects with an industrial robot.</p><p>The tilt of the object is calculated using a RANSAC plane estimator. After the 2D search the differences in height between all corresponding points of the model and the live image are calculated. By estimating a plane to this difference the tilt of the object can be calculated. Using the tilt the model edges are tilted in order to improve the matching at the next scale level.</p><p>The problems that arise with occlusion and missing data have been studied. Missing data and erroneous data have been thresholded manually after conducting tests where automatic filling of missing data did not noticeably improve the matching. The automatic filling could introduce new false edges and remove true ones, thus lowering the score.</p><p>Experiments have been conducted where objects have been placed at increasing tilt angles. The results show that the matching algorithm is object dependent and correct matches are almost always found for tilt angles less than 10 degrees. This is very similar to the original 2D SBM because the model edges does not change much for such small angels. For tilt angles up to about 25 degrees most objects can be matched and for nice objects correct matches can be done at large tilt angles of up to 40 degrees.</p>

<p>In this thesis spacetime analysis is applied to laser triangulation in an attempt to eliminate certain artifacts caused mainly by reflectance variations of the surface being measured. It is shown that spacetime analysis do eliminate these artifacts almost completely, it is also shown that the shape of the laser beam used no longer is critical thanks to the spacetime analysis, and that in some cases the laser probably even could be exchanged for a non-coherent light source. Furthermore experiments of running the derived algorithm on a GPU (Graphics Processing Unit) are conducted with very promising results.</p><p>The thesis starts by deriving the theory needed for doing spacetime analysis in a laser triangulation setup taking perspective distortions into account, then several experiments evaluating the method is conducted.</p>

<p>A laser-triangulating range camera uses a laser plane to light an object. If the position of the laser relative to the camera as well as certrain properties of the camera is known, it is possible to calculate the coordinates for all points along the profile of the object. If either the object or the camera and laser has a known motion, it is possible to combine several measurements to get a three-dimensional view of the object.</p><p>Camera calibration is the process of finding the properties of the camera and enough information about the setup so that the desired coordinates can be calculated. Several methods for camera calibration exist, but this thesis proposes a new method that has the advantages that the objects needed are relatively inexpensive and that only objects in the laser plane need to be observed. Each part of the method is given a thorough description. Several mathematical derivations have also been added as appendices for completeness.</p><p>The proposed method is tested using both synthetic and real data. The results show that the method is suitable even when high accuracy is needed. A few suggestions are also made about how the method can be improved further.</p>

Cette thèse s’inscrit dans le cadre d’une convention industrielle de formation par la recherche (CIFRE) entre le laboratoire Hubert Curien et l’entreprise Pattyn Bakery Division. L’objectif de ces travaux est le développement d’un système de détection de trait laser sur FPGA (Field Programmable Gate Array) qui soit plus performant que système actuel de l’entreprise. Dans l’industrie, les concepteurs de systèmes de vision doivent pouvoir créer et modifier facilement leurs systèmes afin de pouvoir les adapter aux besoins de leurs clients et aux évolutions technologiques. Ainsi les opérateurs développés doivent être génériques afin de permettre aux concepteurs de modifier le système de vision sans nécessairement avoir de compétences matérielles. Les concepteurs doivent également pouvoir être en mesure d’estimer quelles seront les ressources utilisées par l’opérateur en cas modifications du système : paramètres de l’application, capteur, famille de FPGA... Dans ce manuscrit, les principaux algorithmes de détection de trait laser ainsi que leurs propriétés ont été étudiés. Un opérateur de détection de trait laser a été choisi et développé. L’implantation de cet opérateur sur une caméra-FPGA du marché a permis d’obtenir un premier prototype fonctionnel. Les performances temporelles de ce nouveau système sont quatre fois supérieures à celles du système actuellement utilisé par l’entreprise. Le nouveau système est capable de traiter jusqu’à 2500 images par seconde. Enfin, les modèles de la consommation des ressources permettent de dimensionner une architecture à partir d’un ensemble de paramètres prédéfinis de manière rapide et sans faire de synthèses. Le paramètre auquel les concepteurs doivent prêter le plus d’attention est le niveau de parallélisme des données. Ce paramètre permet d’exploiter les capacités de parallélisme du FPGA en consommant plus de ressources. Cependant, les ressources du FPGA sont limitées et augmenter le niveau de parallélisme peut induire la nécessité de changer de FPGA. Le système et les données fournies permettront à l’entreprise d’adapter le système de vision selon les besoins futurs des clients en les guidant vers le choix du matériel / This thesis is part of an industrial research training agreement (CIFRE) between the Hubert Curien laboratory and the company Pattyn Bakery Division. The goal of this work is the development of an FPGA laser line detection system that is more efficient than the current system of the company. In the industry, vision system designers need to be able to easily create and modify their systems in order to adapt them to their customers’ needs and technological developments. Thus developed operators must be generic to allow designers to change the vision system without necessarily having material skills. Designers must also be able to estimate what resources will be used by the operator in case of system changes : application parameters, sensor, family of FPGAs ... In this manuscript, the main laser line detection algorithms and their properties have been studied. A laser line detection operator was chosen and developed. The implementation of this operator on an FPGA-camera from market has resulted in a first functional prototype. The time performance of this new system is four times that of the system currently used by the company. The new system is able to process up to 2500 frames per second. Finally, resource consumption models makes it possible to size an architecture from a set of predefined parameters quickly and without synthesizing. The parameter to which designers must pay the most attention is the level of parallelism of the data. This parameter makes it possible to exploit the parallelism capabilities of the FPGA by consuming more resources. However, the resources of the FPGA are limited and increasing the level of parallelism can induce the need to change the family of FPGAs. The system and the data provided will enable the company to adapt the vision system to the future needs of customers by guiding the choice of equipment.

A novel design for an automated uranium pellet stacking system is presented. This system is designed to replace the manual method for stacking uranium pellets for CANDU fuel bundles that is currently used at Cameco Fuel Manufacturing in Port Hope, ON. The system presented is designed as a drop-in solution to the current production line at Cameco. As a result, there are constraints that prevent certain parameters from modification. The three main goals of this system are to reduce worker exposure to radiation to as low as reasonably achievable, improve product quality, and increase the productivity of the production line. The proposed system will remove the workers from a position of having to handle the uranium pellets and physically place them on the stacks. While the natural uranium currently in production is not a major health risk for short-term exposure, the possibility of production of slightly enriched uranium bundles makes this system a real need. This system also removes the random pellet placement that the manual system uses by taking precise measurements using laser triangulation sensors. These measurements are used to determine which sizes of end pellets are required to complete the stack to within the specified tolerances. A final measurement is done to ensure the stack is within tolerance. All of this information is recorded and can be traced back to the stacks during quality inspection, which is a major improvement over the existing system. This single automated system will replace two manual stations, while increasing the total output production, thus eliminating pellet stacking as a bottleneck in the fuel bundle assembly process. Current production rates can be met by this single, automated station in two shifts per day, while the current manual process requires three shifts using two stations. Test results of a proof-of-concept prototype indicate that the proposed design meets or exceeds all of the design requirements.

In today's industry 3D cameras are often used to inspect products. The camera produces both a 3D model and an intensity image by capturing a series of profiles of the object using laser triangulation. In many of these setups a physical encoder is attached to, for example, the conveyor belt that the product is travelling on. The encoder is used to get an accurate reading of the speed that the product has when it passes through the laser. Without this, the output image from the camera can be distorted due to a variation in velocity. In this master thesis a method for integrating the functionality of this physical encoder into the software of the camera is proposed. The object is scanned together with a pattern, with the help of this pattern the object can be restored to its original proportions. / I dagens industri används ofta 3D-kameror för att inspektera produkter. Kameran producerar en 3D-modell samt en intensitetsbild genom att sätta ihop en serie av profilbilder av objektet som erhålls genom lasertriangulering. I många av dessa uppställningar används en fysisk encoder som återspeglar hastigheten på till exempel transportbandet som produkten ligger på. Utan den här encodern kan bilden som kameran fångar bli förvrängd på grund av hastighetsvariationer. I det här examensarbetet presenteras en metod för att integrera funktionaliteten av encodern in i kamerans mjukvara. För att göra detta krävs att ett mönster placeras längs med objektet som ska bli skannat. Mönstret återfinns i bilden fångad av kameran och med hjälp av detta mönster kan hastigheten bestämmas och objektets korrekta proportioner återställas.

Shape-based matching (SBM) is a method for matching objects in greyscale images. It extracts edges from search images and matches them to a model using a similarity measure. In this thesis we extend SBM to find the tilt and height position of the object in addition to the z-plane rotation and x-y-position. The search is conducted using a scale pyramid to improve the search speed. A 3D matching can be done for small tilt angles by using SBM on height data and extending it with additional steps to calculate the tilt of the object. The full pose is useful for picking objects with an industrial robot. The tilt of the object is calculated using a RANSAC plane estimator. After the 2D search the differences in height between all corresponding points of the model and the live image are calculated. By estimating a plane to this difference the tilt of the object can be calculated. Using the tilt the model edges are tilted in order to improve the matching at the next scale level. The problems that arise with occlusion and missing data have been studied. Missing data and erroneous data have been thresholded manually after conducting tests where automatic filling of missing data did not noticeably improve the matching. The automatic filling could introduce new false edges and remove true ones, thus lowering the score. Experiments have been conducted where objects have been placed at increasing tilt angles. The results show that the matching algorithm is object dependent and correct matches are almost always found for tilt angles less than 10 degrees. This is very similar to the original 2D SBM because the model edges does not change much for such small angels. For tilt angles up to about 25 degrees most objects can be matched and for nice objects correct matches can be done at large tilt angles of up to 40 degrees.

In this thesis spacetime analysis is applied to laser triangulation in an attempt to eliminate certain artifacts caused mainly by reflectance variations of the surface being measured. It is shown that spacetime analysis do eliminate these artifacts almost completely, it is also shown that the shape of the laser beam used no longer is critical thanks to the spacetime analysis, and that in some cases the laser probably even could be exchanged for a non-coherent light source. Furthermore experiments of running the derived algorithm on a GPU (Graphics Processing Unit) are conducted with very promising results. The thesis starts by deriving the theory needed for doing spacetime analysis in a laser triangulation setup taking perspective distortions into account, then several experiments evaluating the method is conducted.