Open Access

We present a 3d-laser-scan simulation in virtual reality for creating synthetic scans of CAD models. Consisting of the virtual reality head-mounted display Oculus Rift and the motion controller Razer Hydra our system can be used like common hand-held 3d laser scanners. It supports scanning of triangular meshes as well as b-spline tensor product surfaces based on high performance ray-casting algorithms. While point clouds of known scanning simulations are missing the man-made structure, our approach overcomes this problem by imitating real scanning scenarios. Calculation speed, interactivity and the resulting realistic point clouds are the benefits of this system.

The improvement of collision avoidance for vessels in close range encounter situations is an important topic for maritime traffic safety. Typical approaches generate evasive trajectories or optimise the trajectories of all involved vessels. Such a collision avoidance system has to produce evasive manoeuvres that do not confuse other navigators. To achieve this behaviour, a probabilistic obstacle handling based on information from a radar sensor with target tracking, that considers measurement and tracking uncertainties is proposed. A grid based path search algorithm, that takes the information from the probabilistic obstacle handling into account, is then used to generate evasive trajectories. The proposed algorithms have been tested and verified in a simulated environment for inland waters.

Um Mauerwerksrisse mit einer Injektion erfolgreich zu schließen, sind bei der praktischen Durchführung des Injektionsverfahrens eine Reihe von Details zu beachten: Sie betreffen das Bohren und Setzen der Packer, das Mischen und Einbringen des Füllstoffs, das Schließen der Öffnungen und Fertigstellen der Sichtmauerwerksoberflächen sowie die Dokumentation und Kontrolle des Injektionserfolgs.

In biomechanics laboratories the ground reaction force time histories of the foot-fall of persons are usually measured using a force plate. The accelerations of the floor, in which the force plate is embedded, have to be limited, as they may influence the accuracy of the force measurements. For the numerical simulation of vibrations induced by humans in biomechanical laboratories, loading scenarios are defined. They include continuous motions of persons (walking, running) as well as jumps, typical for biomechanical investigations on athletes. The modeling of floors has to take into account the influence of floor screed in case of portable force plates. Criteria for the assessment of the measuring error provoked by floor vibrations are given. As an example a floor designed to accommodate a force platform in a biomechanical laboratory of the University Hospital in Tübingen, Germany, has been investi-gated for footfall induced vibrations. The numerical simulation by a finite element analysis has been validated by field measurements. As a result, the measuring error of the force plate installed in the laboratory is obtained for diverse scenarios.