91 Fahrzeugkonstruktion
Filtern
Erscheinungsjahr
Dokumenttyp
Sprache
- Englisch (159) (entfernen)
Schlagworte
- Conference (89)
- Konferenz (86)
- Germany (54)
- Deutschland (53)
- Safety (49)
- Sicherheit (48)
- Accident (44)
- Unfall (44)
- Anfahrversuch (41)
- Fahrzeug (38)
Institut
During the last 5 years, the number of cars fitted with side airbags has dramatically increased. They are now standard equipment, even on many smaller cars or less luxurious vehicles. While some side airbags offer thoracic protection alone, there are those that combine thoracic and head protection (of which most deploy from the seat). Other systems employ separate airbags for head and thorax protection, which are designed to be effective noticeably in a crash against a pole. This paper proposes an evaluation of the effectiveness of side airbags in preventing thoracic injuries to passenger car occupants involved in side crashes. First, the target population (who can take benefit of side airbag deployment and in what circumstances) is defined. Side airbags can be especially effective in cases of impacts on the door with intrusion at a certain impact speed. Then, an example case of a side impact with side airbag deployment is given were side airbag deployment is thought to have had a positive effect on injury outcome. A further case is presented where the impact configuration is likely to have reduced the effect of side airbag deployment on injury outcome. Finally, the estimation of side airbag effectiveness (in terms of additional occupant protection brought exclusively by the airbag) is proposed by comparing injury risk sustained by occupants in (more or less) similar cars (fitted or non fitted with airbags) because, during these years, car structure, and side airbag conception have considerably evolved. In-depth accident data from France, the UK and Germany has been collected. Out of 2,035 side impact accident cases available in the databases, we selected 435 occupants of passenger cars (built from 1998 onwards) involved in an injury accident between year 1998 and year 2004 for EES (Energy Equivalent Speed) values between 20km/h and 50km/h. The occupants, belted or not, were sat on the struck side, whatever the obstacle and type of accidents (intersection, loss of control, etc.). For multiple impact crashes, the side impact is assumed to be the more severe one. Passenger cars were fitted with (96) or without (339) side airbags. Most of the potential risk explanatory variables were correctly and reliably reported in the databases (velocity " impact zone " impact angle " occupant characteristics, etc.). The analysis compared injury risks for different levels of EES and different types of side airbags. A logistic regression model was also computed with injury variables (such as thoracic AIS 2+ or AIS 3+) as the dependant variable and other variables (including airbag type and EES) as explanatory injury risk factors. Results revealed statistically non-significant reductions in thoracic AIS 2+ and AIS 3+ injury risk in side airbag equipped cars in the impact violence range selected (odds ratio between 0.84 and 0.98 depending on types of airbags). The results are discussed. The non-significance is assumed to be due to a low number of cases. Statistical analysis for head injuries was not possible due to the low number of accident cases with passenger cars fitted with head airbags in the databases. Moreover, the discrepancies between the data coming from different countries (especially calculation of EES) might have introduced instability in the analysis.
This study is aimed to investigate the correlations of impact conditions and dynamic responses with the injuries and injury severity of child pedestrians by accident reconstruction. For this purpose, the pedestrian accident cases were selected from Sweden and Germany with detailed information about injuries, accident cars, and accident environment. The selected accident cases were reconstructed using mathematical models of pedestrian and passenger car. The pedestrian models were generated based on the height, weight, and age of the pedestrian involved in accidents. The car models were built up based on the corresponding accident car. The impact speeds in simulations were defined based on the reported data. The calculated physical quantities were analyzed to find the correlation with injury outcomes registered in the accident database. The reconstruction approaches are discussed in terms of data collection, estimating vehicle impact speeds, pedestrian moving speeds and initial posture, secondary ground impact, validity of the mathematical models, as well as impact biomechanics.
The current Brussels EU Regulation No. 1235/2011, valid from May 30, 2012, has introduced an European Tyre Label with wet grip index G classes from A to G for passenger car tyres C1, light commercial vehicles tyres C2 and heavy truck- and bus tyres C3. Every wet grip class for each vehicle category has a defined band of numerical values for the wet grip index G. The legislated wet grip values G in this EU- Regulation are very low. The measured braking distances and corresponding impact speeds of the test vehicles are showing very critical results. Regulation No. 1235/2011 of the European Parliament and the Council for Type Approval of Vehicles (EU) should be changed in such a way, that for C1-tyres (normal passenger cars tyres) the minimum wet grip index G is 1.25. All C2-tyres (light commercial vehicles tyres) should at least meet a minimum wet grip index of G = 1.1. All C3-tyres (heavy trucks and buses tyres) should at least meet a minimum wet grip index of G = 0.95. Due to the missing lower limits for G in the wet grip class F for C1, C2 and C3 tyres according to Commission Regulation (EU) No. 1235/2011, officially valid from 30 May 2012, a tyre-to-road coefficient of adhesion in the extreme of 0 (zero) is legally permitted. This is an apparent flaw in above cited EU Regulation, which causes a potential danger to the road traffic safety for all motor vehicles in Europe with such tyres. The wet grip class F has to be removed urgently from said EURegulation, since a direct liability of the responsible EU-Commission can not be excluded.
Past European collaborative research involving government bodies, vehicle manufacturers and test laboratories has resulted in a prototype barrier face called the Advanced European Mobile Deformable Barrier (AE-MDB) for use in a new side impact test procedure . This procedure offers a better representation of the current accident situation and, in particular, the barrier concept is a better reflection of front-end stiffness seen in today- passenger car fleet compared to that of the current legislative barrier face. Based on the preliminary performance corridors of the prototype AE-MDB, a refined AE-MDB specification has been developed. A programme of barrier to load cell wall testing was undertaken to complete and standardise the AE-MDB specification. Barrier faces were supplied by the four leading manufacturers to demonstrate that the specification could be met by all. This paper includes background, specification and proof of compliance.
Rear-end collisions are the most frequent same and opposite-direction crashes. Common causes include momentary inattention, inadequate speed or inadequate distance. While most rear-end collisions in urban traffic only result in vehicle damage or slight injuries, rear-end collisions outside built-up areas or on motorways usually cause fatal or serious injuries. Driver assistance systems that detect dangerous situations in the longitudinal vehicle direction are therefore an essential safety plus. In view of this, for ADAC, systems that alert drivers to dangerous situations and initiate autonomous braking complement ESC as one of the most important active safety features in modern vehicles. The aim of ADAC is to provide consumers with technical advice and competent information about the systems available on the market. Reliable comparative tests that are based on standardised test criteria may provide motorists with important information and help them make a buying decision. In addition, they raise consumer awareness of the systems and speed up their market penetration. The assessment must focus on as many aspects of effectiveness as possible and include not only autonomous braking but also collision warning and autonomous brake assist. The work of the ADAC accident research is the development of the testing scenarios with direct link to accident situations and the identification of useful test criteria for testing.
Impact severity is a fundamental measure for all in-depth crash investigation projects. One methodology used in the UK is based on the US Calspan software package CRASH3. The UK- in-depth crash investigation studies routinely use AiDamage3 a software package which is based on an updated version of the original CRASH3 algorithm, including enhancements to the vehicle stiffness coefficients. Real world accident-damaged vehicles are measured and their crush is correlated with a library of stiffness coefficients. These measurements are then used, along with other parameters, to calculate the crash energy and equivalent changes of velocity of the vehicles (delta-v), which is a measure of the impact severity. UK in-depth accident studies routinely validate the crash severity methodologies applied as the vehicle fleet changes. This is achieved by analysing crash test data and using the appropriate residual crush damage and other inputs to AiDamage3 and checking the program- outputs with the known crash severity parameters. This procedure checks, at least in part, the default stiffness values in the data libraries and the reconstruction methods used.
Side-impact safety of passenger cars is assessed in Europe in a full-scale test using a moving barrier. The front of this barrier is deformable and represents the stiffness of an 'average' car. The EU Directive 96/27/EC on side impact protection has adopted the EEVC Side Impact Test Procedure, including the original performance specification for the barrier face when impacting a flat dynamometric rigid wall. The requirements of the deformable barrier face, as laid down in the Directive, are related to geometrical characteristics, deformation characteristics and energy dissipation figures. Due to these limited requirements, many variations are possible in designing a deformable barrier face. As a result, several barrier face designs are in the market. However, research institutes and car manufacturers report significant difference in test results when using these different devices. It appears that the present approval test is not able to distinguish between the different designs that may perform differently when they impact real vehicles. Therefore, EEVC Working Group 13 has developed a number of tests to evaluate the different designs. In these tests the barrier faces are loaded and deformed in a specific and/or more representative way. Barrier faces of different design have been evaluated. In the paper the set-up and the reasoning behind the tests is presented. Results showing specific differences in performance are demonstrated.
The term test procedure refers to a method that describes how a system has to be tested to identify and assess specific behavior or properties by experiments. This also includes the specification of required tools, equipment, boundary conditions, and evaluation methods. Test procedures are an essential tool to check whether desired product properties are present, which of course also applies to the development of driver assistance systems. In addition to development and release testing that mainly is performed by the vehicle or system manufacturer, there are tests with the purpose of an independent product testing that are conducted by external test organizations. These tests are needed for vehicle type approval (for admission to a specific market), in the context of applying the standard for functional safety (in both cases mainly executed by technical services (being accredited as certification laboratory)) or for customer information purposes (by a test institute for consumer protection). The focus of this chapter is these "external" test methods. After a taxonomy of test procedures, the differences between legislation (type approval) and consumer testing are highlighted. Typical tests and the associated test setup, tools, and assessment criteria are discussed, and an outlook toward testing in the near and mid-future is given.
In spite of today's highly sophisticated crash test procedures like the different NCAP programs running world-wide, bad real world crash performance of cars is still an issue. There are crash situations which are not sufficiently represented by actual test configurations. This is especially true for car to car, as well as for car to object impacts. The paper describes reasons for this bad performance. The reasons are in principal bad structural interaction between the car and its impact partners (geometric incompatibility), unadjusted front end stiffness (stiffness incompatibility) and collapse of passenger compartments. To show the efficiency of improving cars' structural behaviour in accidents with different impact partners an accident data analysis has been taken out by members of European Project VC-COMPAT. Accident data analysis has shown that in Germany between 15,000 and 20,000 of the now severely injured car occupants might get less injured and between 600 and 900 car occupant fatalities might be saved. Similar results arise for the UK.
Although the bus belongs to the safest traffic means, single accidents can be particularly severe and concern many passengers. Especially in case of fires a high number of injured and killed persons can be the outcome. Fire safety of buses therefore is of high importance. With the increase of plastic materials as a material for the interior equipment of buses and coaches due to their good mechanical properties combined with low weight, the question arises whether the safety level has decreased in case of a fire during the last years " also compared to other means of transport. Because of the combustible plastics and their ability to release a high amount of heat the main fire load in buses is no longer the fuel but the plastic materials which are also often easy to ignite. Besides the flammability of the equipments, also the production of smoke, the smoke development and propagation as well as its toxicity are of interest. That counts for the passengers as well as for the test methods and its limit values. The severe fire in Germany near Hanover in 2008 with 20 fatalities showed how disastrous such fires can be. For those reasons several research projects were initiated on behalf of the German Federal Highway Research Institute. At the one hand the fire behaviour of coach interiors was examined in general focusing on fire propagation as well as fire detection and signalling. As result, recommendations with regard to early fire detection systems for the engine compartments and onboard extinguishing equipment were elaborated. On the other hand research was carried out to examine heat release, smoke, smoke propagation and its toxicity due to burning bus interior materials. In this project small and real scale experiments on material specimens, interior parts and vehicles were performed. Trains and buses often have very similar operation conditions. Consequently, bus interior material was tested according to the regulations for rail vehicles, i.e. DIN EN 45545 as well as DIN 5510. None of the tested bus interior materials would have been allowed to use in a train. The fire safety regulations for bus materials are on a low level compared to other transport sectors, i.e. railway, ship and aircraft. Also numerical investigations with the Fire Dynamics Simulator (FDS) were performed. The very rapid fire development during the severe bus fire from 2008 could be predicted with the numerical model. The model was then used to investigate the influence of different materials, ventilation conditions and ignition sources. The bus materials contribute significantly to a very rapid fire development in bus fires. Especially, the flammable ceiling and the passenger seats were identified to be key issues of the fire propagation in a bus and can be explained by the rapid fire spread along the ceiling and the high fire load of passenger seats. As conclusion of the project effective and economically reasonable fire safety requirements for interiors of buses are recommended which would improve the current situation. Proposals for amendments of current requirements are recommended including the specification of appropriate limit values. In particular, it is taken into consideration which reasonable fire safety standards from other transport sectors, especially the rail sector, should be transferred to buses
The aim of this study was to evaluate the performance and accuracy of Event Data Recorders (EDRs). The analysis was based on J-NCAP crash tests from 2006"2007, with the corresponding EDR datasets. The pre-crash velocity, maximum delta-V and delta-V versus time history data recorded in the EDRs were compared with the reliable crash test data. The difference between the EDR pre-crash velocity and the laboratory test speed was less than 4 percent. In contrast, in several cases the maximum delta-V and delta-V versus time history data obtained from the EDRs showed uncertainty of measurement in comparisons with the reliable delta-V data. The difference in maximum delta-V in these comparisons was more than 5 percent in 10 of 14 tests and more than 10 percent in 4 of 14 tests. The EDRs underestimated the maximum delta-V in almost all tests. It was also concluded that the calculated acceleration from the EDR delta-V versus time history data showed good agreement with the instrumented accelerometer signal during the collision in almost all tests.
Within the automotive context camera monitor systems (CMS) can be used to present views of the traffic situation behind the vehicle to the driver via a monitor mounted inside the cabin. This offers the opportunity to replace classical outside rearview mirrors and therefore to implement new design concepts, aerodynamically optimized vehicle shapes and to reduce the width of the vehicle. Further, the use of a CMS offers the potential to implement functionalities like warnings or situation-adaptive fields of view that are not feasible with conventional rearview mirrors. Despite these potential advantages, it is important to consider the possible technical constraints of this technology and its effect on driver perception and behavior. On the technical side next to the field of view and die robustness of die system, aspects as its functionality at day and night as well as under varying weather conditions should be object to scientific investigation. Concerning human machine interaction, it has to be considered, that the perception of velocities and distances of approaching vehicles might be different for CMS as compared to conventional rearview mirrors and potential influences of factors as the Position of the displays or drivers' age should be taken into account. In order to shed light on these and further open issues, BASt is currently conducting a study that will cover the use of CMS under controlled conditions as well in real traffic. The first part of the study will focus on passenger cars, while in a second step the empirical investigation will be extended to heavy goods vehicles, where the potentials as well as the limitations of CMS might differ considerably. The presentation will cover the first part, with regard to the experimental design, implementation and initial results if already available.
Technical progress in automotive engineering focuses at the moment on two competing branches: improving safety and reducing energy consumption. Recent consideration has been given to a third factor, cost to the consumer. Challenges are presented by demographic changes, especially with increasing participation of elderly people in road traffic. The report considers the recent history of road accidents in Germany and statistics relating to vehicle population and road performance. There is a general trend towards decreasing numbers of accidents and their severity. Transport is responsible for roughly 20% of CO2 emissions and approximately 70% of total petroleum consumption. The Federal Government has responded to these challenges by publishing the Freight Transport and Logistics Masterplan in the summer of 2008. It describes the strategic transport policy direction and the key elements of the future course of action which are to be used to ensure the provision of efficient infrastructure and, at the same time, to reduce the amount of energy consumed by vehicles and make transport more efficient, cleaner and quieter. This document contains a number of concrete measures subsumed under the following six objectives: Making optimum use of transport infrastructure - shaping transport to make it more efficient; Reducing the number of journeys - ensuring mobility; Transferring more traffic to the railways and inland waterways; Upgrading more transport arteries and hubs; Environmentally friendly, climate friendly, quiet and safe transport, and Good working conditions and good training in the freight transport industry. Progress in research is outlined in the following areas: Daytime Running Lights for Motorcycles; Safety of hydrogen vehicles - addressing safety and environmental issues by development of a Global Technical Regulation for hydrogen vehicles; Elements of active vehicle safety for elderly drivers; Periodical Technical Inspection of electronically controlled systems in road vehicles - Electronic Stability Control; Pedestrian protection; Crash Compatibility - role of collision partner in passive safety tests; Child safety; Euro NCAP - Child Restraint Systems, and German Field Operational Test on Car-to-Car and Car-to-Infrastructure Systems (SIM-TD). The research project AKTIV - "Adaptive and Cooperative Technologies for Intelligent Traffic" encompasses the design, development, and evaluation of novel driver assistance systems, knowledge and information technologies and is set up to find solutions for efficient traffic management and Car-to-Car and Car-to-Infrastructure communication for future cooperative vehicle applications. The European Statement of Principles on the Human Machine Interface (HMI), presented at the eSafety Conference, which was held in Berlin on 5/6 June 2007, addresses issues such as Real Time Traffic Information (RTTI), Legal issues of Advanced Driver Assistance Systems (ADAS) and e-security.
Topics of the status report are: Road accidents in Germany " Socio-economic costs due to road traffic accidents in Germany " Vehicle population and road performance " Electromobility " Alternative power train technologies: market penetration and consequences. The following research subjects are presented: Safety of electric vehicles " Driving dynamics of electric propelled vehicles " New requirements for the periodic technical inspection of electric and hybrid vehicles " Forward looking safety systems " Periodic roadworthiness tests " Cooperative systems: integration of existing systems " Safety related traffic information " Urban space: User oriented assistance systems and network management " Automated driving " Study on camera-monitor-systems " Freight transport " BioRID TEG, dummy harmonization " Frontal impact and compatibility " Child safety " FlexPLI " GIDAS: a blueprint for worldwide in-depth road accident investigations " Druid: Driving under the influence of drugs, alcohol and medicines " Smoke and toxicity in bus fires.
Topics of this report are: Road accidents in Germany - Socio-economic costs due to road traffic accidents - Vehicle population and road performance " Automotive IT " Electromobility. The following research subjects are presented: Safety of electric vehicles - Forward looking safety systems - Cooperative systems - Safety related traffic information - Freight transport: Action plan freight transport and trial with longer trucks - Lane departure warning systems and Advanced emergency braking systems (AEBS) for heavy duty vehicles - Dummy harmonization " Compatibility - Child safety - Virtual testing - Driving under the influence of drugs, alcohol and medicines - Fire safety of buses - Milled shoulder rumble strips - Conspicuity of powered-two-wheelers - Automatically dipped high beam and rear view mirrors.
Topics of this report are: Securing mobility and making mobility sustainable - Strategies for road safety: Safe behavior, Safe vehicles, Safe infrastructure, Telematics, International vehicle-engineering measures " Accident statistics " Accident research " Passive vehicle safety " Active vehicle safety " Driver assistance systems " Environmental protection through vehicle engineering.
The sequence of accident events can be classified by three essential phases, the pre-crash-sequence, the crash-sequence and the post-crash-sequence. The level of reliability of the information in the GIDAS-database (German In Depth Accident Study) is provided predominantly on the passive side. The period to evaluate active safety systems begins already in the pre-crash-sequence. The assessment of the potential of sensor- or communication-based active safety systems can only be accomplished by a detailed analysis of the pre-crash-phase. Hence the necessity to analyze the early period of the accident event in detail arises. This is possible with the help of the digital sketches of the accident site and the simulation of the accident by a simulation method of the VUFO GmbH. After simulating the pre-crash scenario it is possible to generate additional and standardized data to describe the pre-crash-sequences of an accident in a very high detail. These data are documented in a second database called the GIDAS Pre-Crash-Matrix (PCM). The PCM contains various tables with all relevant data to reproduce the pre-crash-sequence of traffic accidents from the GIDAS database until 5 seconds before the first collision. This includes parameters to describe the environment data, participant data and motion or dynamic data. This paper explains the creation of the PCM, the simulation itself and the contents and structure of the PCM. With this information of the pre-crash-sequence for various accident scenarios an improved benefit estimation and development of active safety systems can be made possible.
The focus of the technical innovation in the automobile industry is currently changing to sensor based safety systems, which are operating in the pre-crash phase of an accident. To get more information about this pre-crash phase for real accidents a simulation of this phase using the GIDAS database is done. The basics for this simulation are geometrical information about the accident location and the exact accident data out of the GIDAS database. This aggregated information gives the possibility to simulate an exact motion for every accident participant, using MATLAB / SIMULINK, in the pre-crash phase. After the simulation the information about the geometrical positions, the velocities and maneuvers of the drivers to an individual TTC (time to collision) are available. With those results it is possible to develop new useful sensor geometries using pre-crash scatter plots or estimate the efficiency of implemented active safety systems in combination with sensor characteristics. This simulation can be done for every reconstructed accident included in the GIDAS database, so these results can represent a wide spread basis for the further development of active safety systems and sensor geometries and characteristics
In most of developed countries, the progress made in passive safety during the last three decades allowed to drastically reduce the number of killed and severely injured especially for occupants of passenger cars. This reduction is mainly observed for frontal impacts for which the AIS3+ injuries has been reduced about 52% for drivers and 38% for front passengers. The stiffening of the cars' structure coupled with the generalization of airbags and the improvement of the seatbelt restraint (load limiter, pretension, etc.) allowed to protect vital body regions such as head, neck and thorax. However, the abdomen did not take advantage with so much success of this progress. The objective of this study is to draw up an inventory on the abdominal injuries of the belted car occupants involved in frontal impact, to present adapted counter-measures and to assess their potential effectiveness. In the first part the stakes corresponding to the abdominal injuries will be defined according to types of impact, seat location, occupants' age and type of injured organs. Then, we shall focus on the abdominal injury risk curves for adults involved in frontal impact and on the comparisons of the average risks according to the seat location. In the second part we will list counter-measures and we shall calculate their effectiveness. The method of case control will be used in order to estimate odds ratio, comparing two samples, given by occupants having or not having the studied safety system. For this study, two type of data sources are used: national road injured accident census and retrospective in-depth accident data collection. Abdominal injuries are mainly observed in frontal impact (52%). Fatal or severe abdominal occupant- injuries are observed at least in 27% of cases, ranking this body region as the most injured just after the thorax (51%). In spite of a twice lower occupation rate in the back seats compared to the front seats, the number of persons sustaining abdominal injuries at the rear place is higher than in the front place. In recent cars, the risk of having a serious or fatal abdominal injury in a frontal impact is 1.6% for the driver, 3.6% for the front passenger and 6.3% for the rear occupants. The most frequently hurt organs are the small intestine (17%), the spleen (16%) and the liver (13%). The most common countermeasures have a good efficiency in the reduction of the abdominal injuries for the adults: the stiffness of the structure of the seats allows decreasing the abdominal injury risk from 54% (driver) to 60% (front occupant), the seatbelt pretensioners decrease also this risk from 90% (driver) to 83% (front passenger).
This work aims at bringing evidence for mass incompatibility in frontal impact for cars built according to the UNECE R94 regulation. French national injury accidents database census for years 2005 to 2008 were used for the analysis. The heterogeneity of frontal self-protection among cars of different masses is investigated, as well as the partner protection parameter offered by these cars. The last part of the analysis deals with the estimation of the benefit, in terms of fatal and severe injuries avoided, if crashworthiness was harmonized for the whole fleet of vehicle. This calculation is done for France and is extended to all Europe.