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- 2016 (9) (entfernen)
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- Abteilung Fahrzeugtechnik (9) (entfernen)
Camera-monitor systems (CMS) can be used in motor vehicles to display the driver's rear view on a monitor mounted inside the vehicle. This also offers the possibility of replacing conventional exterior mirrors with suitable CMS and thereby implementing new design concepts with aerodynamic advantages. However, as exterior mirrors are safety-relevant vehicle parts for securing the driver's indirect rear view (requirements specified in UN Regulation No. 46), the question arises whether CMS can provide an equivalent substitute for mirrors. In the scope of this study, CMS and conventional exterior mirrors were compared and assessed in test drives and static tests under different external conditions. On the one hand, the examination of technical aspects, and on the other hand, issues pertaining to the design of the human-machine interaction, were the objects of the study. Two vehicles were available for the trials with passenger vehicles: A vehicle, manufactured in small series, which is already equipped with CMS as sole replacement for the exterior mirrors, as well as a compact class vehicle which had a CMS retrofitted by the car manufacturer in addition to conventionally used exterior mirrors. The latter could be covered exclusively for trips with CMS. A tractor unit with semitrailer was available for the truck trials. The driver's cabin was equipped with a CMS system developed by the vehicle manufacturer. In general, it was shown that it is possible to display the indirect rear view sufficiently for the driver, both for cars and trucks, using CMS which meet specific quality criteria. Depending on the design, it is even possible to receive more information about the rear space from a CMS than is possible with mirror systems. It was also shown that the change from mirrors to CMS requires a certain period of familiarisation. However, this period is relatively short and does not necessarily result in safety-critical situations.
Kamera-Monitor-Systeme (KMS) können bei Kraftfahrzeugen dazu verwendet werden, die Sicht nach hinten für den Fahrer auf einem im Fahrzeug montierten Monitor darzustellen. Dies bietet auch die Möglichkeit, herkömmliche Außenspiegel durch geeignete KMS zu ersetzen und damit neue Designvarianten mit aerodynamischen Vorteilen umsetzen zu können. Da es sich bei den Außenspiegeln jedoch um ein sicherheitsrelevantes Fahrzeugteil zur Gewährleistung der indirekten Sicht nach hinten handelt (Anforderungen sind in der UN-Regelung Nr. 46 festgelegt), stellt sich die Frage, ob KMS einen gleichwertigen Ersatz für Spiegel bieten können. In der vorliegenden Studie wurden das KMS und der herkömmliche Außenspiegel während der Durchführung von Versuchsfahrten und statischen Tests unter verschiedenen äußeren Bedingungen verglichen und bewertet. Untersuchungsgegenstand waren zum einen technische Aspekte, zum anderen Fragestellungen zur Gestaltung der Mensch-Maschine-Interaktion. Für die Versuche mit Pkw standen zwei Fahrzeuge zur Verfügung: Ein Fahrzeug, das in Kleinserie hergestellt wird und bereits nur mit KMS als Ersatz für Außenspiegel ausgerüstet ist, sowie ein Fahrzeug der Kompaktklasse, an dem sowohl ein KMS als Nachrüstsatz verbaut war als auch die herkömmlich vorhandenen Außenspiegel. Letztere konnten für Fahrten ausschließlich mit KMS abgedeckt werden. Für die Versuche am Lkw stand eine Sattelzugmaschine mit Auflieger zur Verfügung. Die Fahrerkabine war mit einem nachgerüsteten KMS ausgestattet. Grundsätzlich hat sich gezeigt, dass es möglich ist, die indirekte Sicht nach hinten sowohl bei Pkw als auch bei Lkw durch KMS, die gewisse Qualitätskriterien erfüllen, für den Fahrer ausreichend darstellen zu können. Je nach Ausgestaltung bietet ein KMS sogar die Möglichkeit, mehr Information über den rückwärtigen Raum zu präsentieren als es mit Spiegelsystemen möglich ist. Es hat sich auch gezeigt, dass der Umstieg von Spiegeln auf KMS immer einer gewissen Gewöhnungsphase bedarf, diese jedoch verhältnismäßig kurz ist und nicht notwendigerweise zu sicherheitskritischen Situationen führt.
Estimation of the effects of new emission standards on motorcycle emissions by means of modeling
(2016)
Road traffic is, in addition to the energy sector and the industry, one main source of air pollution and carbon dioxide emissions. Although most countries and manufacturers agreed to environmental regulations to reduce the pollutant emissions, particularly in urban areas with high traffic density, the impact of road traffic emissions on the environment and human health has been growing in importance steadily. Due to stricter emission standards and the binding use of emission-reducing systems (e.g. three-way catalyst) hydrocarbon emissions from passenger cars have been reduced significantly since the last two decades. Unlike to passenger cars the emissions standards of powered two-wheelers have not been adjusted since 2006 although their share of hydrocarbon emissions to the total amount of hydrocarbon emissions of road traffic is estimated to be disproportionately high. Due to the new regulation (EU) No. 168/2013 powered two-wheelers have to fulfill new emission standards from 2016 (Euro 4) and 2020 (Euro 5) onwards. Besides new limits for the tailpipe emissions the evaporative emissions are regulated separately for the first time, as they make up a high proportion to the total hydrocarbon emissions in this vehicle class. In this context, the calculation and forecast of road traffic emissions is an important tool to verify compliance of climate targets and to assess the reduction potential of emission-reducing systems. For that purpose the Federal Highway Research Institute (BASt) uses the emission- and calculation tool TREMOD (Transport Emission Model) which provides baseline data and calculated results for pollutants in almost every differentiation e.g. vehicle category, traffic situation and road type. Moreover, estimations of future emission trends, stock information and mileage distribution can be made. The main objective is to illustrate the impact of the upcoming emission standards Euro 4 and Euro 5 on the operational hydrocarbon emissions of powered two-wheelers based on statistical estimations. The significant aspect is to generate scenarios to show the reduction potential of hydrocarbon emissions of powered two-wheelers, differentiated into motorcycles and small motorcycles, in relation to the total share of hydrocarbon emissions in this vehicle class and to the total hydrocarbon emissions from road traffic. As a part of their research, the authors can make initial statements about the possible effect of the new emission standards of regulation (EU) No. 168/2013 by means of modeling with TREMOD.
In line with the new definition introduced by the European Commission (EC), the number of seriously injured road casualties in Germany for 2014 is assessed in this study. The number of MAIS3+ casualties is estimated by two different methodological approaches. The first approach is based on data from the German Inâ€Depth Accident Study (GIDAS), which is closely related to the German Road Traffic Accident Statistics. The second approach is based on data from the German TraumaRegister DGU-® (TRâ€DGU), which includes many more hospitals but not all MAIS3+ injuries.
Statischer und dynamischer Fahrsimulator im Vergleich: Wahrnehmung von Abstand und Geschwindigkeit
(2016)
Die Methodik der experimentellen Fahrsimulation gewährleistet sichere Anwendungsforschung unter hoher Kontrollierbarkeit. Obwohl gegenwärtig viele Forschungsfragen in virtuellen Umgebungen beantwortet werden, existieren weder systematische Validierungsszenarien für Fahrsimulatoren, noch wurde die Vergleichbarkeit der Aussagekraft von Befunden aus Fahrsimulatoren mit und ohne Bewegungssystem bislang angemessen hinterfragt. Daher sollen in der vorliegenden Studie ein statischer und ein dynamischer Fahrsimulator hinsichtlich ihrer Validität in verschieden Fahrsituationen verglichen werden, wobei der Schwerpunkt auf Abstands- und Geschwindigkeitswahrnehmung liegt. Es wird erwartet, dass ein zusätzliches Bewegungssystem nur bei Fahraufgaben mit dynamischer Involvierung einen Redundanzgewinn für die Wahrnehmung des Fahrers liefert. Werden hingegen konstante Abstände eingehalten, sollten entsprechend der Hypothese beide Prüfumgebungen äquivalente Resultate zeigen. Insgesamt durchfuhren 60 Probanden Fahrszenarien zur Abstandsherstellung und -einschätzung, teils mit Okklusion, sowie Folgefahrten mit Beschleunigung und Verzögerung. Die Querführung wurde mithilfe einer Gassendurchfahrt untersucht. Indem die virtuelle Umgebung nach Vorbild einer real existierenden Teststrecke konstruiert wurde, kann ebenfalls auf reale Referenzwerte Bezug genommen werden. Die Ergebnisse weisen auf eine vergleichbare relative Validität zwischen statischem und dynamischem Simulator hin, wenn keine Kinetik in der Fahraufgabe vorhanden ist. In Beschleunigungssituationen bewirkt simulierte Fahrdynamik signifikante Wahrnehmungseinbußen, wobei das Bewegungssystem in Bremssituationen die Wahrnehmung signifikant unterstützt. In dem Querführungsszenario ist die Fahrgeschwindigkeit im statischen Simulator zwar signifikant höher und damit näher an der realen Referenz, allerdings wird im statischen Simulator eine auffällig nach rechts versetzte Spur gehalten. Dennoch, so der vorrangige Befund, sollte auch ein statischer Fahrsimulator valide Evaluationen für die meisten Fahraufgaben gewährleisten.
Established in 1997, the European New Car Assessment Programme (Euro NCAP) provides consumers with a safety performance assessment for the majority of the most popular cars in Europe. Thanks to its rigorous crash tests, Euro NCAP has rapidly become an important driver safety improvement to new cars. After ten years of rating vehicles, Euro NCAP felt that a change was necessary to stay in tune with rapidly emerging driver assistance and crash avoidance systems and to respond to shifting priorities in road safety. A new overall rating system was introduced that combines the most important aspects of vehicle safety under a single star rating. The overall rating system has allowed Euro NCAP to continue to push for better fitment and higher performance for vehicles sold on the European market. In the coming years, the safety rating is expected to play an important role in the support of the roll-out of highly automated vehicles.
Automated driving will provide many kinds of benefits - some direct and some indirect. The benefits originate at the individual level, from changes in the behaviour of drivers and travellers with regard to driving and mobility, ending up with benefits at the social level via changes in the whole transport system and society, where many of the current planning and operations paradigms are likely to be transformed by automated driving. There may also be disbenefits, particularly at a social level, for example in intensity of travel which could result in additional congestion and increased use of natural resources. There may also be unintended consequences. For example, we do not know the impacts on public transport: driverless vehicles could provide a means to a lower cost service provision, but the availability of automated cars could lead to more car travel at the expense of collective transport.
There is considerable evidence for the negative effects of driver distraction on road safety. In many experimental studies, drivers have been primarily viewed as passive receivers of distraction. Thus, there is a lack of research on the mediating role of their self-regulatory behavior. The aim of the current study was to compare drivers' performance when engaged in a system-paced secondary task with a self-paced version of this task and how both differed from baseline driving performance without distraction. Thirty-nine participants drove in a simulator while performing a secondary visual"manual task. One group of drivers had to work on this task in predefined situations under time pressure, whereas the other group was free to decide when to work on the secondary task (self-regulation group). Drivers' performance (e.g., lateral and longitudinal control, brake reaction times) was also compared with a baseline condition without any secondary task. For the system-paced secondary task, distraction was associated with high decrements in driving performance (especially in keeping the lateral position). No effects were found for the number of collisions, probably because of the lower driving speeds while distracted (compensatory behavior). For the self-regulation group, only small impairments in driving performance were found. Drivers engaged less in the secondary task during foreseeable demanding or critical driving situations. Overall, drivers in the self-regulation group were able to anticipate the demands of different traffic situations and to adapt their engagement in the secondary task, so that only small impairments in driving performance occurred. Because in real traffic drivers are mostly free to decide when to engage in secondary tasks, it can be concluded that self-regulation should be considered in driver distraction research to ensure ecological validity.
Motorcycling is a fascinating kind of transportation. While the riders' direct exposure to the environment and the unique driving dynamics are essential to this fascination, they both cause a risk potential which is several times higher than when driving a car. This chapter gives a detailed introduction to the fundamentals of motorcycle dynamics and shows how its peculiarities and limitations place high demands on the layout of dynamics control systems, especially when cornering. The basic principles of dynamic stabilization and directional control are addressed along with four characteristic modes of instability (capsize, wobble, weave, and kickback). Special attention is given to the challenges of braking (brake force distribution, dynamic over-braking, kinematic instability, and brake steer torque induced righting behavior). It is explained how these challenges are addressed by state-of-the-art brake, traction, and suspension control systems in terms of system layout and principles of function. It is illustrated how the integration of additional sensors " essentially roll angle assessment " enhances the cornering performance in all three categories, fostering a trend to higher system integration levels. An outlook on potential future control systems shows exemplarily how the undesired righting behavior when braking in curves can be controlled, e.g., by means of a so-called brake steer torque avoidance mechanism (BSTAM), forming the basis for predictive brake assist (PBA) or even autonomous emergency braking (AEB). Finally, the very limited potential of brake and chassis control to stabilize yaw and roll motion during unbraked cornering accidents is regarded, closing with a promising glance at roll stabilization through a pair of gimbaled gyroscopes.