91 Fahrzeugkonstruktion
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.
In 2016 the seventh ESAR conference (Expert Symposium on Accident Research) was held in Hannover. ESAR is an international convention of experts, who analyze traffic accidents all over the world and discuss their results in this context, conducted at the Medizinische Hochschule Hannover every 2 years. It connected representatives of public authorities, engineers in automotive development and scientists and offers a forum with particular emphasis on In-Depth-Analyses of accident statistics and accident analyses. Special focus is placed on research on the basis of so-called "In-Depth-Accident-Investigations" [data collections at the sites of the accidents], which are characterized by extensive documentations of the sites of the accidents, of the vehicles as well as of the injuries, encompassing several scientific fields. ESAR aims at a multi-disciplinary compilation of scientific results and at discussing them on an international, scientific level. It is thus a scientific colloquium and a platform for exchanging information for all accident researchers. Experiences in accident prevention as well as in the complex field of accident reconstruction are stated and new research fields are added. Existing results of long-term research work in Europe, the US, Australia and Japan include different infrastructural correlations and give findings on population, vehicle population and driver characteristics, which offer a basis for recommendations to be derived and measures for increasing road safety.
Fahrerassistenzsysteme unterstützen den Fahrer durch Information, Warnung oder Eingriff in die Fahrzeugsteuerung. Zukünftige Systeme zur Kollisionsvermeidung oder bis hin zum automatischen Fahren werden den Fahrer immer mehr entlasten. Wegen ihres erheblichen Potenzials zur Verbesserung vor allem der aktiven Sicherheit können die Fahrerassistenzsysteme wesentlich zur Vermeidung von Unfällen oder der Reduktion von Unfallfolgen beitragen. Andererseits können Fahrerassistenzsysteme aufgrund des komplexen Systemzusammenhangs zwischen Fahrer, Fahrzeug und Umwelt negative Auswirkungen auf das Verkehrsgeschehen haben. Dieser Aspekt muss schon bei der Entwicklung der Systeme berücksichtigt werden. Die Empfehlung der Europäischen Kommission zur Gestaltung von Informations- und Kommunikationssystemen gibt dazu Leitlinien vor. Die BASt ist mit der wissenschaftlichen Begleitung der Thematik beauftragt. Die Industrie ist dazu aufgefordert darzulegen, welche Maßnahmen zur Einhaltung der Grundsätze ergriffen worden sind beziehungsweise werden. Um das Potenzial der Fahrerassistenzsysteme zur Steigerung der Verkehrssicherheit voll ausschöpfen zu können, sind weiterhin Forschungsarbeiten zur Entwicklung neuer und zur Weiterentwicklung bestehender Systeme unter Berücksichtigung der Gestaltungsanforderungen für sichere Assistenzsysteme durchzuführen.
Assessment of the effectiveness of Intersection Assistance Systems at urban and rural accident sites
(2015)
An Intersection Collision Avoidance System is a promising safety system for accident avoidance or injury mitigation at junctions. However, there is still a lack of evidence of the effectiveness, due to the missing real accident data concerning Advanced Driver Assistance Systems. The objective of this study is the assessment of the effectiveness of an Intersection Collision Avoidance System based on real accidents. The method used is called virtual pre-crash simulation. Accidents at junctions were reconstructed by using the numerical simulation software PC-Crashâ„¢. This first simulation is called the baseline simulation. In a second step the vehicles of these accidents were equipped with an Intersection Collision Avoidance System and simulated again. The second simulation is called the system simulation. In the system simulation two different sensors and four different intervention strategies were used, based on a time-to-collision approach. The effectiveness of Intersection Collision Avoidance System has been evaluated by using an assessment function. On average 9% of the reviewed junction accidents could have been avoided within the system simulations. The other simulation results clearly showed a change in the principal direction of force, delta-v and reduction of the injury severity.
The Traffic Accident Research Institute at University of Technology Dresden investigates about 1,000 accidents annually in the area around and in Dresden. These datasets have been summarized and evaluated in the GIDAS (German Accident In-Depth Study) project for 13 years. During the project it became apparent that the specific traffic situation of a covert exit of a passenger car and an intersecting two-wheeler involves a high risk potential. This critical situation develops in a large part due to the lack of visibility between the driver and the intersecting bike. In this paper the accident avoidance potential of front camera systems with lateral field of view, which allows the driver to have an indirect sight into the crossing street area will be presented.
Nach einer Reisebusunfallserie im Jahre 1992 wurde die Bundesanstalt für Straßenwesen beauftragt ein Expertengespräch durchzuführen und eine Projektgruppe einzurichten, um Schwachstellen im Sicherheitssystem des Reisebusverkehrs aufzudecken, Verbesserungsvorschläge zu erarbeiten und den Forschungsbedarf zu identifizieren. Der Beitrag befasst sich schwerpunktmäßig mit den ökonomischen Rahmenbedingungen und der Sicherheit, den Ausbildungs- und Eignungsfragen der Busfahrer, deren Belastung und Beanspruchung, der Einhaltung und Kontrolle von Vorschriften, der Erhöhung der kraftfahrzeugtechnischen Sicherheit sowie dem Notfall- und Unfallmanagement. Zur Weiterentwicklung des Sicherheitssystems wird eine auf breite Mitwirkung auch von Beteiligten angelegte Sicherheitsforschung für den Wirtschaftsverkehr empfohlen. Aus den untersuchten Feldern werden Empfehlungen abgeleitet und der notwendige Forschungsbedarf aufgeführt.
The project UR:BAN "Cognitive assistance (KA)" aims at developing future assistance systems providing improved performance in complex city traffic. New state-of-the-art panoramic sensor technologies now allow comprehensive monitoring and evaluation of the vehicle environment. In order to improve protection of vulnerable road users such as pedestrians and cyclists, a particular objective of UR:BAN is the evaluation and prediction of their behaviour and actions. The objective of subproject "WER" is development support by providing quantitative estimates of traffic collisions at the very start and predict potential in terms of optimized accident avoidance and reduction of injury severity. For this purpose an integrated computer simulation toolkit is being devised based on real world accidents (GIDAS as well as video documented accidents), allowing the prediction of potential effectiveness and future benefit of assistance systems in this accident scenario. Subsequently, this toolkit may be used for optimizing the design of implemented assistance systems for improved effectiveness.
The evaluation of the expected benefit of active safety systems or even ideas of future systems is challenging because this has to be done prospectively. Beside acceptance, the predicted real-world benefit of active safety systems is one of the most important and interesting measures. Therefore, appropriate methods should be used that meet the requirements concerning representativeness, robustness and accuracy. The paper presents the development of a methodology for the assessment of current and future vehicle safety systems. The variety of systems requires several tools and methods and thus, a common tool box was created. This toolbox consists of different levels, regarding different aspects like data sources, scenarios, representativeness, measures like pre-crash-simulations, automated crash computation, single-case-analyses or driving simulator studies. Finally, the benefit of the system(s) is calculated, e.g. by using injury risk functions; giving the number of avoided/mitigated accidents, the reduction of injured or killed persons or the decrease of economic costs.
Für eine quantitativ exakte Beschreibung der mit der Gefahrgutbeförderung verbundenen Risiken fehlen sowohl statistische Voraussetzungen als auch eine wissenschaftlich begründete Risikoanalyse. Eine Risikoanalyse der Gefahrgutbeförderung soll zweckmäßigerweise auf Transportketten und nicht auf den direkten Vergleich von Verkehrsträgern abstellen. Zentrale Kategorie zur Definition des Risikos sollte dabei der Unfall sein. Zusammen mit der Transportleistung sollte er das Risiko als Wahrscheinlichkeitsaussage beschreiben. Mit in die Risikobestimmung einzubeziehen ist die Unfallschwere. Im Rahmen des Beitrages schlägt eine Projektgruppe eine dreistufig angelegte Risikoanalyse vor. Die Bausteine dieser Risikoanalyse bestehen aus 1. einer mathematisch-statistischen Risikoanalyse, 2. einer Schwachstellenanalyse und 3. einem Systemmodell zur ständigen Analyse des Gefahrgutbeförderungsrisikos. Dazu werden in dem Forschungsbericht grundsätzliche Überlegungen zur Risikobewertung angestellt, auf das Regelwerk des Gefahrguttransportes eingegangen, Ausbildung, Training und Überprüfung der Fahrzeugführer behandelt sowie auf das Gefahrgut und die Gefahrgutumschließung eingegangen. Ferner befasst sich der Bericht mit der Fahrzeugtechnik, der Verkehrsinfrastruktur, Informationssystemen und der Sicherheit im Gefahrguttransport in den neuen Bundesländern. Zum Schluss werden Forschungsempfehlungen bezüglich der Sicherheit in der Gefahrgutbeförderung formuliert.
EEVC Status report
(2001)