Safety Relevant Positioning Applications in Rail Traffic using the European Satellite System "Galileo"

Die Ortung im Eisenbahnverkehr hat eine hohe sicherheitstechnische Relevanz. Eine falsch detektierte Position eines Fahrzeugs kann zu einer erheblichen Gefährdung führen, da die ermittelte Ortsinformation für die Freigabe und das Wiederbesetzen von Gleisabschnitten genutzt wird. Daraus abgeleitet, müssen Ortungssysteme bei der Zulassung unter anderem die folgenden sicherheitskritischen Anforderungen erfüllen Genauigkeit, Zuverlässigkeit, Integrität und Verfügbarkeit der Ortungsinformation, die gemäß SIL 4 nachzuweisen sind

Future information and assistance systems for train drivers and evaluation of their usability

Even though train protection systems are used to avoid critical situations, the train driver remains responsible for the continuous monitoring of signal aspects and derivation of suitable actions. This requirement persists, although the position of signals shifts more and more from external signals to in-cab displays, especially with advanced levels of train protection and automatic train control. Errors in the detection and interpretation of signal- or display information and driver distraction may lead to severe accidents. Aim of our research at the Institute of Transportation Systems (ITS) is to develop innovative concepts of the train driver’s workplace in order to secure a safe and efficient railway system that keeps the driver ‘in the loop’. Therefore, we follow a user centred approach. The train driver participates directly in the development and evaluation process of new systems supporting the work in the driver’s cabin. Using our driver’s cabin simulator recently built at the ITS as a flexible vehicle platform in a simulation environment, we are able to investigate the driving behaviour and the train driver’s information processing during his or her task. From the results, we derive concepts in order to optimize the presentation of necessary information and give recommendations how to assist the train driver. In the present paper, first concepts for supporting the train driver in keeping attention and also our simulation environment and the methodology used are described

Modeling Driving Behavior at Roundabouts: Impact of Roundabout Layout and Surrounding Traffic on Driving Behavior

Driving behavior prediction at roundabouts is an important challenge to improve driving safety by supporting drivers with intelligent assistance systems. To predict the driving behavior effciently steering wheel status was proven to have robust predictability based on a Support Vector Machine algorithm. Previous research has not considered potential effects of roundabout layout and surrounding traffic on driving behavior, but that consideration can certainly improve the prediction results. Therefore, this study investigated how roundabout layout and surrounding traffic impact driving behavior of an ego car. A simulator study was conducted to collect driving behavior data with different roundabout layout settings and different surrounding cyclist position settings. The local minima/maxima of the steering angle was found to have a logarithmic relationship with the roundabout geometric feature. The impact of the surrounding traffic on the ego driver behavior was also found: When there were surrounding cyclists, the recognition rate of ego driver behavior patterns reached 100% later than when there was no surrounding traffic. In conclusion, driving behavior at roundabouts is effected by both roundabout layout and surrounding traffic, and the relationship can be expressed in a quantitative way

Operational and technical testing of the European Train Control System (ETCS)

The European train control system (ETCS) is one of the core parts of the European rail traffic management system (ERTMS) [1]. It has been specified by a European team in the last years [2]. The specification is published by the European Railway Agency (ERA). Different industry suppliers developed products according to this specification. Now those products have to be tested according to the testing requirements. Technical tests are used to prove that the product fulfil the technical requirements of the specification. They are called the conformity tests. Operational tests are used to show that the system fulfils the operational requirements of the railway operator. The idea presented here aims to show, that technical tests as well as operational tests can be defined according to a common standard. The main advantage of this approach is to perform the tests in the same lab environment. The system under test should be integrated in the Lab only once. Both kinds of tests can be executed without any modification of the lab integration. This leads on the one hand to a significant reduction of integration effort in the lab and on the other hand to a reduction of redundancy in the tests itself. This second increase in efficiency needs a methodical basis for the definition of the tests to be executed. This methodical base supports the optimization of the tests. Practically seen the approach allows identifying which parts of the requirements are already tested in the technical tests. In the next step the operational tests are designed by using test cases from the technical tests and adding the missing operational test cases. Finally the operational tests can be designed by focussing on the requirements which not tested yet. The full contribution shows the method of designing tests and the suitable test environment. As a perspective an approach for the generation of field test templates from the operational lab tests is given. The approach used for the conformity tests for ETCS can be extended for operational and safety lab tests as well as for operational field tests. The method of the generation of the test sequences can be used for the different types of tests. The optimization criteria as well as the rules for the parameterization differ for the different kinds of tests. If the same approach for the formalisation and parameterization is used, the lab environment can be used for any type of test

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements