Das Vehicle in the Loop : Ein Werkzeug für die Entwicklung und Evaluation von sicherheitskritischen Fahrerassistenzsystemen

Das „Vehicle in the Loop (VIL)“ ist eine Test- und Simulationsumgebung für Fahrerassistenzsysteme, welche die Vorzüge eines realen Versuchsfahrzeugs mit der Sicherheit und Reproduzierbarkeit von Fahrsimulatoren kombiniert. Als Werkzeug für Entwickler ausgelegt, wurde das VIL weiterentwickelt, um auch als Evaluationswerkzeug für sicherheitskritische Fahrerassistenzsysteme eingesetzt werden zu können. Hierfür wurde das VIL mit neuen Komponenten aufgebaut und auf eine vollständig virtuelle Visualisierung umgestellt. Mit Hilfe einer Validierungsstudie wurde geprüft, ob das VIL reales Fahrerverhalten abbildet. Hierbei konnte relative Validität bezüglich Reaktionszeit und aufgebrachtem Bremsdruck nachgewiesen werden. Gleichzeitig diente die Studie dazu, während des Aufbaus identifizierte Schwachstellen zu bestätigen und weitere Ansätze für die Verbesserung des VIL zu finden. Hierbei wurden drei Ansätze für eine Verbesserung des VIL aufgedeckt, welche näher betrachtet wurden. Bei der Auswahl des Head Mounted Displays (HMD) wurde beim Aufbau darauf geachtet, dass das darstellbare Blickfeld möglichst dem des Menschen entspricht. Jedoch war das ausgewählte HMD schwer und unhandlich, so dass dieses in einer zweiten Studie mit einem kleineren, leichteren HMD aber kleinerem Blickfeld verglichen wurde. Hierbei konnte gezeigt werden, dass das kleinere Blickfeld keinen signifikanten Einfluss auf das Fahrerverhalten hat. Zudem wurde das kleinere und leichtere HMD auch von den Probanden klar bevorzugt, so dass sich dieses als sinnvoll für die Verwendung im VIL durchsetzte. Der verwendete optische Tracker zur Verfolgung der Kopfausrichtung des Fahrers stellte im ersten VIL Aufbau die Fahrerbewegung nur stark verzögert dar. Deswegen wurde ein Headtracking-Verfahren entwickelt, welches die aktuelle Ausrichtung des Fahrerkopfs mit Hilfe von einem optischen Tracker und zwei Drehratensensoren berechnet und die Bewegung zusätzlich prädiziert, so dass die Latenz bei der Darstellung von Fahrerbewegungen signifikant verringert wurde. Durch den Einsatz einer VR-Visualisierung verliert der Fahrer die gewohnte Sicht auf den Innenraum des Fahrzeugs. Hierdurch geht die Möglichkeit der Interaktion mit dem Fahrzeug verloren und der Fahrer hat das Gefühl über die Straße zu fliegen. Um dem entgegen zu wirken, wurde ein Augemented Reality Konzept auf Basis von video-see-through erarbeitet, welches es ermöglicht, dem Fahrer sowohl den Fahrzeuginnenraum, wie auch die virtuelle Welt, in welcher er sich bewegt, darzustellen. Es konnte gezeigt werden, dass das Konzept viel Potential für eine bessere Darstellung im VIL bietet, dieses aber noch Verbesserungen bedarf bevor es im VIL für Probandenstudien eingesetzt werden kann. Durch die Weiterentwicklung des VIL hat dieses mittlerweile einen Reifegrad erreicht, welches erlaubt das VIL als kostengünstiges Werkzeug für die Entwicklung und Evaluation von sicherheitskritischen Fahrerassistenzsystemen einzusetzen.The Vehicle in the Loop (VIL) is a test and simulation tool to develop and evaluate driving assistant systems. Its greatest advantage is that the VIL combines the real driving experience with the safety and replicability of a driving simulator. Initially designed as a developer tool, the VIL was further developed to extend its field of operation to the evaluation of safety systems in the automotive context. For this purpose, the original VIL was reconstructed with the use of new hardware components and a virtual reality visualization. To proof that the VIL is capable of eliciting and promoting naturalistic driving behavior, an evaluation study was conducted in which driving scenarios were compared in reality and the VIL. In addition the evaluation study aimed at identifying further development needs. Initially a Head Mounted Display (HMD) with a field of view comparable to the natural field of view was chosen. However, it turned out that the weight and the lack of comfort of the device dominated the overall negative feedback given by participants. Thus, in an additional study, a smaller HMD was compared with the first HMD to identify the pivotal features that provide the best visual and wearing experience. Furthermore, the optical head tracker used for measuring the driver’s current head pose turned out to show a time lag which is perceived by the driver and thus affects the driving experience. Therefore, the head tracking hardware was supplemented with gyroscopes to additionally measure the drivers’ head turning rate. Based on the different sensor signals, a sensor fusion algorithm was implemented which reduces the lag. An additional reduction is achieved with a prediction of the head pose. In combination, these measures reduced the perceived lag in the head tracking significantly. Due to the virtual reality visualization, the driver has no visual feedback of the car interior. Furthermore, this visualization creates the feeling of flying over the street. To emphasize the impression of driving a car, a proof of concept for an augmented reality based on video-see-through was developed and evaluated. Hereby, the driver’s view is filmed by a camera which is mounted on the HMD. Before visualizing, the camera image is augmented with the virtual reality, which results in a view of the car’s interior and the virtual reality instead of the windshield’s view. It could be shown that the new concept of augmented reality based on video-see-through has a high potential to make driving in the VIL even more realistic. However, the concept requires further improvement before it can be used for the evaluation of driving assistant systems. Due to the reported advances in technological development, the VIL with virtual reality visualization has currently reached a level of technological readiness which enables the VIL to be used as a tool to develop and evaluate automotive safety assistance systems. Future developments show potential to promote naturalistic driving with the VIL even further

Anthracene-based thiol-ene networks with thermo-degradable and photo-reversible properties

Reversible networks based on an alkenefunctionalized dimer of 9-anthracenemethanol were synthesized by photoinitiated radical thiol ene polyaddition, using either a poly(dimethylsiloxane-co-propylmercaptomethylsiloxane) or a novel aliphatic trithiol synthesized from 1,2,4trivinylcyclohexane in a simple two-step procedure. The obtained networks were analyzed using differential scanning calorimetry, dynamic mechanical analysis, polarization microscopy, X-ray diffraction, and (photo)rheology. The two types of networks showed weak endothermic transitions between 50 and 60 degrees C, which proved to originate either from melting of a crystalline anthracene-dimer phase (trithiol network) or from a liquid crystalline phase (PDMS network) based on X-ray diffraction and polarization microscopy. Using rheology, both types of networks were shown to cleanly decompose into multifunctional anthracene monomers at temperatures above 180 degrees C. Irradiation of these anthracene monomers resulted in the formation of networks having similar physical properties as the original materials

Reference intervals for plasma, urinary, and salivary concentrations of free metanephrines in dogs:Relevance to the diagnosis of pheochromocytoma

Background: Measurement of free metanephrines is recommended for screening of pheochromocytoma (PCC) but requires appropriate reference intervals (RIs). Hypothesis/Objectives: To report RIs for plasma, urinary and salivary concentrations of free metanephrines and to determine the diagnostic performance of plasma free normetanephrine (pNMN) and metanephrine (pMN) concentrations in dogs with PCC, hypercortisolism (HC), and nonadrenal illness (NAI). Animals: Eighty healthy dogs, 11 PCC dogs, 25 HC dogs, 6 NAI dogs. Methods: Plasma, urine, and saliva were collected prospectively from healthy dogs, and free metanephrine concentrations were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, medical records of dogs that had plasma free metanephrine concentrations measured by LC-MS/MS between 2018-2021 were studied retrospectively. Results: The RIs for free metanephrines in plasma, urine and saliva are reported. Dogs with PCC had significantly higher pNMN than dogs with HC (P &lt;.001) and NAI (P =.002). The PCC dogs had significantly higher pMN than HC dogs (P &lt;.001), but not higher than NAI dogs (P =.29). Using the upper reference limit, pNMN (&gt;3.56 nmol/L) showed high sensitivity (100%, 95% confidence interval [CI]: 72-100) and specificity (94%, 95% CI: 79-99) for diagnosis of PCC, whereas pMN (&gt;2.49 nmol/L) showed moderate sensitivity (73%, 95% CI: 39-94) and high specificity (94%, 95% CI: 79-99). Conclusions and Clinical Importance: With establishment of these RIs, biochemical testing for PCC in dogs can be substantially improved. Measurement of pNMN is superior to pMN in dogs with PCC.</p

Environmental effect on egress simulation

Abstract. Evacuation and egress simulations can be a useful tool for studying the effect of design decisions on the flow of agent movement. This type of simulation can be used to determine before hand the effect of design decisions and enable exploration of potential improvements. In this work, we study at how agent egress is affected by the environment in real world and large scale virtual environments and investigate metrics to analyze the flow. Our work differs from many evacuation systems in that we support grouping restrictions between agents (e.g., families or other social groups traveling together), and model scenarios with multiple modes of transportation with physically realistic dynamics (e.g., individuals walk from a building to their own cars and leave only when all people in the group arrive).

Testing of inoculation methods and susceptibility testing of perspective cabbage breeding lines (Brassica oleracea convar. Capitata) to the black rot disease caused by xanthomonas campestris pv. campestris

The susceptibility of twenty-four cabbage breeding lines to Xanthomonas campestris pv. campestris was evaluated. The selection of appropriate inoculation method was done on 4 cabbage cultivars ('Cerox', 'Sintex', 'Sonja' and 'Avak'). One month old plants were infected by 5 inoculation methods (spraying, injection by syringe, multiple pricking, carborundum abrasion and scissor clipping method). Four different bacterial isolates of Xcc (WHRI 3811, 3971A, 1279A; SU) and their mixture were evaluated for the aggressiveness on 'Cerox' and 'Sonja' cultivars. On the basis of obtained results, breeding lines of head cabbage were inoculated by mixture of all tested isolates using multiple pricking method. The disease severity of inoculated seedlings proved high susceptibility of young plants to the Xcc infection. The disease incidence determined 75 and 105 days after sowing showed changes for 16 of tested lines and indicated that resistance testing should be observed until mature stage. The study revealed five breeding lines (DP25, T1, IT10, Kalibos and Avak1) with disease incidence lower than 20 % as perspective sources of resistance for further breeding.O

Газоносність вугільних пластів та фізико-механічнині властивості порід покрівлі і підошви поля шахти № 1 ”Тяглівська” Львівсько-Волинського басейну

Сопоставлены данные по изучению газоносности угольных пластов поля шахты № 1 ―Тягловская‖ и физико-механическим свойствам пород их непосредственной кровли и подошвы. Благоприятными яляются условия для выработки пластов b4, n8 в, n8. Несколько сложнее – для пластов n9, n7 в, n7 1, что вызвано низкой стойкостью пород кровли. Наиболее сложной прогнозируется ситуация для эксплуатации пласта n7 из-за низной стойкости и способности его кровли к обрушениям. Угольные пласты (кроме b4) находятся в метановой зоне. Их газоносность значительна, содержание метана в газовой смеси высокое. Это будет составлять дополнительные трудности при эксплуатации.Data on studies of the gas-bearing potential of coal seams of the Tyagliv-1 mine field are correlated as well as physical-mechanical properties of their immediate base and roof. Favorable conditions are known to exist for working of the seams b4, n8 в, n8. Somewhat more composite ones are observed for the seams n9, n7в, n7 1 that was caused by low stability of the roof rocks. The most composite situation is forecasted for exploitation of the seam n7 one to low stability and ability of its roof for landslides. Coal seams (exsepting b4) lie in the methane zone. Their gas-bearing potential is suffcient, methane content in a gas mixture is high. That will cause additional difficalties in the process of exploitation