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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.
The United Nations Economic Commission for Europe Informal Group on GTR No. 7 Phase 2 are working to define a build level for the BioRID II rear impact (whiplash) crash test dummy that ensures repeatable and reproducible performance in a test procedure that has been proposed for future legislation. This includes the specification of dummy hardware, as well as the development of comprehensive certification procedures for the dummy. This study evaluated whether the dummy build level and certification procedures deliver the desired level of repeatability and reproducibility. A custom-designed laboratory seat was made using the seat base, back, and head restraint from a production car seat to ensure a representative interface with the dummy. The seat back was reinforced for use in multiple tests and the recliner mechanism was replaced by an external spring-damper mechanism. A total of 65 tests were performed with 6 BioRID IIg dummies using the draft GTR No.7 sled pulse and seating procedure. All dummies were subject to the build, maintenance, and certification procedures defined by the Informal Group. The test condition was highly repeatable, with a very repeatable pulse, a well-controlled seat back response, and minimal observed degradation of seat foams. The results showed qualitatively reasonable repeatability and reproducibility for the upper torso and head accelerations, as well as for T1 Fx and upper neck Fx. However, reproducibility was not acceptable for T1 and upper neck Fz or for T1 and upper neck My. The Informal Group has not selected injury or seat assessment criteria for use with BioRID II, so it is not known whether these channels would be used in the regulation. However, the ramping-up behavior of the dummy showed poor reproducibility, which would be expected to affect the reproducibility of dummy measurements in general. Pelvis and spine characteristics were found to significantly influence the dummy measurements for which poor reproducibility was observed. It was also observed that the primary neck response in these tests was flexion, not extension. This correlates well with recent findings from Japan and the United States showing a correlation between neck flexion and injury in accident replication simulations and postmortem human subjects (PMHS) studies, respectively. The present certification tests may not adequately control front cervical spine bumper characteristics, which are important for neck flexion response. The certification sled test also does not include the pelvis and so cannot be used to control pelvis response and does not substantially load the lumbar bumpers and so does not control these parts of the dummy. The stiffness of all spine bumpers and of the pelvis flesh should be much more tightly controlled. It is recommended that a method for certifying the front cervical bumpers should be developed. Recommendations are also made for tighter tolerance on the input parameters for the existing certification tests.
This thesis gives a detailed picture of how planners, politicians, residents and transport engineers in three societies, Britain, Germany and the United States reacted to one of the most powerful inventions of the late nineteenth century, the motor car. Misjudgments of the potential growth of motor vehicle ownership and its adverse effects had serious repercussions in the coming decades, primarily in the dense urban areas. Disturbing has been the underestimation of the importance of public transport as a real alternative to the motor car in urban areas, first by the United States and even several decades later by Britain. Of the three countries, only Germany seems to have struck a better balance. Not surprisingly, already at the beginning of the twentieth century, conflicts occurred between the weaker road participants (pedestrians and cyclists), the existing urban fabric and the motor vehicle. A more comprehensive comparison between Britain and Germany shows that both countries developed specific patterns and had different attitudes towards road transport. Far more has been invested and planned in Germany whereas Britain has shown not so much a lack of foresight in planning but 'in investment in road transport. This major difference has had very visible effects an today's urban structure and transport situation. The demand for restraint of motor traffic had different motives in the two countries, and is not such a new idea as is often assumed. While in Germany even in the 1920s and 30s the protection of historic inheritance was a decisive motive, in Britain that was not the case. Questions of traffic restraint were however raised in connection with road safety and later in the 60s as a means of improving the urban environment. The turning point of nearly unlimited promotion of car use in urban areas took place in Germany during the 60s and 70s, whereas the Buchanan Report had already warned in the early 60s against the adverse effects cars could have in urban areas if they were not controlled. Although even in Britain the report was misunderstood and largely not put into practice, the wave of protest against road building occurred earlier there than in Germany. As a whole, Britain has shown a brillance of ideas in restraining motor vehicles which was lacking in the Federal Republic. At the beginning of the 70s, discussions started seriously in Germany an traffic calming concepts which were slowly transformed into reality, Britain seems to have followed these examples, but with a considerable time lag.
The first version of German Highway Capacity Manual was published in 2001. Now, a new version is published in 2015 (HBS 2015). For the new German Highway Capacity Manual, most major chapters are revised and some of them are totally rewritten. The chapter for merge, diverge, and small weaving segments is rewritten in accordance with forthcoming developments in the past 10 years. In this paper, an overview of the chapter in the new German Highway Capacity Manual is presented. Procedures dealing with performance analyses and level of service (LOS) of those segments are introduced both for freeways and rural highways. Differences between the former version and the new version of the chapter in the German Highway Capacity Manual are indicated and discussed. In most of the existing highway capacity manuals, LOS of merge, diverge, and small weaving segments is traditionally defined by speed, volume, or density in critical areas. In that traditional concept several capacity values of different critical areas (merge, diverge, and weaving) as well as upstream and downstream basic segments within the influence areas are evaluated separately. In the new HBS 2015, a new model which considers the total merge, diverge, and weaving segment as an entire object is incorporated. A combined volume-to-capacity ratio (freeways) or a combined density (rural highways) is used for defining the LOS of the total segment. The parameters of the new procedure are functions of the number of lanes of the major road, the number of lanes in the on-ramp or off-ramp, and the predefined geometric design of those segments. The coefficients are calibrated with field data or defined by experts" experiences within a matrix of coefficients. With those procedures, the traffic quality (LOS) can be obtained directly as a function of the volumes or densities on the major road and on the on-ramp or off-ramp respectively. The new procedure has the following advantages: a) a uniform function for all types of merge, diverge, and small weaving segments, b) traffic quality assessment for all critical areas under investigation in one step, and c) the procedure can easily be calibrated. For applications in practice, a set of graphs is provided.
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.
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.
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.
Fire incidents are among the most relevant for people in a tunnel. Therefore, it is important to be sufficiently prepared for such events. A large scale fire test is to be used to help evaluate the initial burning duration and the time it takes for the fire to spread to other vehicles in the tunnel, and in particular how long it takes for a truck carrying wooden pallets to catch fire, taking into consideration the extremely high temperatures. The goal, therefore, is to determine the time it takes for a fire to spread to other vehicles in the tunnel. In the large scale fire test, an accident in a tunnel with one-way traffic is simulated between a truck loaded with approximately 3.7 t of wooden Europol pallets and a passenger car. Directly behind each of the vehicles involved in the accident there is another car which stops at a distance of 1.0 m. Approximately 300 litres of burning diesel are discharged from the truck's fuel tank, which is simulated by using approximately 400 litres of isopropanol. A 10 m-² burning pool forms underneath the truck. Other objectives of the large scale fire test are the validation of the CFD models and the evaluation of the progression of the thermal release ratios estimated for the simulation. The thermal release ratios generated in the test are determined and evaluated using various models.
The Swedish National Road Administration (SNRA), the Japanese Automobile Research Institute (JARI) and the Federal Highway Research Institute (BASt) are co-operating in the International Harmonized Research Activities on Intelligent Transportation Systems (IHRA-ITS). Under this umbrella a joint study was conducted. The overall objective of this study was to contribute to the definition and validation of a "battery of tools" which enables a prediction and an assessment of changes in driver workload due to the use of in-vehicle information systems (IVIS) while driving. In this sense \"validation\" means to produce empirical evidence from which it can be concluded that these methods reliably discriminate between IVIS which differ in terms of relevant features of the HMI-design. Additionally these methods should also be sensitive to the task demands imposed on the driver by the traffic situation and their interactions with HMI-design. To achieve these goals experimental validation studies (on-road and in the simulator) were performed in Sweden, Germany and Japan. As a common element these studies focused on the secondary task methodology as an approach to the study of driver workload. In a joint German-Swedish on-road study the Peripheral Detection Task (PDT) was assessed with respect to its sensitivity to the complexity of traffic situations and effects of different types of navigation systems. Results show that the PDT performance of both the German and the Swedish subjects reflects the task demands of the traffic situations better than those of the IVIS. However, alternative explanations are possible which will be examined by further analyses. Results of this study are supplemented by the Japanese study where informational demands induced by various traffic situations were analysed by using a simple arithmetic task as a secondary task. Results of this study show that relatively large task demands can be expected even from simple traffic situations.
This paper deals with the determination of test criteria for the durability assessment of polyvinyl chloride (PVC)-based geosynthetic barriers (GBR-P) products in tunnel sealing systems. In the project different products for road tunnel application are investigated by systematic long time storage in hot water using a new test procedure based on SIA V 280 standard (test no. 13) and EN 14415. The objective of this research project is to derive suitable exposure conditions and criteria for a practical testing procedure with regard to service lifetimes of up to 100 years. For that test temperature and time as well as the best suitable test medium have been investigated in a structured way. To verify the results of the new test procedure the material properties of GBR-P samples removed from older road tunnels are investigated. Based on the presented results of the still on-going research program some preliminary conclusions regarding the updating of the German regulations for road tunnel sealing systems (ZTV-ING part 5 section 5 and TL/TP KDB) are given.
Improving the security of critical road infrastructure is a major task for owners and operators of tunnels and bridges in the European TEN-T Network (Trans-European Networks of Transport) (European Parliament and Council 1996). Up to now, there has not been a systematic procedure for identifying and assessing critical infrastructure objects and selecting appropriate protection measures. The EC FP7 project SeRoN for the first time presents an innovative methodology in order to support road owners and operators in handling this complex task. This paper describes the methodology and project results in detail by giving an introduction into its practical application.
Safety of light goods vehicles - findings from the German joint project of BASt, DEKRA, UDV and VDA
(2011)
Light goods vehicles (LGVs) are an important part of the vehicle fleet, providing a vital component in the European transportation system. On the other hand, LGVs are in the focus of public discussion regarding road safety. In order to analyse the accident situation of LGVs in an objective manner, Federal Highway Research Institute (BASt), VDA, DEKRA and German Insurers Accident Research (UDV) launched a joint project. The aim of this project, which will be finished by mid of 2011, is to identify reasonable measures which will further improve the safety of LGVs. For the first time, these partners jointly together conducted a research project and put together their know-how in accident research. Analyses are based on real-life accident data from the GIDAS database, the Accident Database of UDV (UDB), the DEKRA database and national statistics. The findings deliver answers to questions within the arena of future legislative actions and consumer protection activities. The analyses of databases cover areas of primary and secondary safety of LGVs with a special focus on advanced driver assistance systems (ADAS), driver behaviour as well as partner and occupant protection. Key figures from national statistics are used to highlight hotspots of accidents of LGVs in Germany. Finally, the proposed countermeasures are assessed regarding their potential effectiveness. Amongst others, the results show that the accident situation of LGVs is very similar to that of passenger cars. Noteworthy variations could be found in collisions with pedestrians, at reversing and regarding accident causes. Occupant safety of LGVs is on a higher level compared to cars. Results indicate that seatbelt use is on a significantly lower level compared to cars. This leads to higher-than-average injury risk for unbelted LGV occupants. When it comes to partner protection, there are problems with compatibility at LGVs. For car occupants there is a very high injury risk when colliding with a LGV. It indicates that higher passive safety test standards for LGVs would be counterproductive if they further increase stiffness of LGVs. The analysis of LGV-pedestrian accidents shows that pedestrian kinematic differs significantly from car-pedestrian accidents. At this point, existing pedestrian related test standards developed for cars cannot be adopted to LGVs. When it comes to active safety, ESC proved its effectiveness once again. Beyond that, rear view cameras, advanced emergency braking systems and lane departure warning systems show a safety potential, too. In addition to any technical countermeasures previously discussed, the importance of the driver behavior and attitude regarding the accident risk was investigated. In order to develop successful actions it is important to understand the main target population. In the case of LGV especially the crafts business and smaller companies are the major contributors the safety issue.
Test and assessment procedures for passive pedestrian protection based on developments by the European Enhanced Vehicle-safety Committee (EEVC) have been introduced in world-wide regulations and consumer test programmes, with considerable harmonization between these programmes. Nevertheless, latest accident investigations reveal a stagnation of pedestrian fatality numbers on European roads running the risk of not meeting the European Union- goal of halving the number of road fatalities by the year 2020. The branch of external road user safety within the EC-funded research project SENIORS under the HORIZON 2020 framework programme focuses on investigating the benefit of modifications to pedestrian test and assessment procedures and their impactors for vulnerable road users with focus on the elderly. Injury patterns of pedestrians and cyclists derived from the German In-Depth Accident Study (GIDAS) show a trend of AIS 2+ and AIS 3+ injuries getting more relevant for the thorax region in crashes with newer cars (Wisch et al., 2017), while maintaining the relevance for head and lower extremities. Several crash databases from Europe such as GIDAS and the Swedish Traffic Accident Data Acquisition (STRADA) also show that head, thorax and lower extremities are the key affected body regions not only for the average population but in particular for the elderly. Therefore, the SENIORS project is focusing on an improvement of currently available impactors and procedures in terms of biofidelity and injury assessment ability towards a better protection of the affected body regions, incorporating previous results from FP 6 project APROSYS and subsequent studies carried out by BASt. The paper describes the overall methodology to develop revised FE impactor models. Matched human body model and impactor simulations against generic test rigs provide transfer functions that will be used for the derivation of impactor criteria from human injury risk functions for the affected body regions. In a later step, the refined impactors will be validated by simulations against actual vehicle front-ends. Prototyping and adaptation of test and assessment procedures as well as an impact assessment will conclude the work of the project at the final stage. The work will contribute to an improved protection of vulnerable road users focusing on the elderly. The use of advanced human body models to develop applicable assessment criteria for the revised impactors is intended to cope with the paucity of actual biomechanical data focusing on elderly pedestrians. In order to achieve optimized results in the future, the improved test methods need to be implemented within an integrated approach, combining active with passive safety measures. In order to address the developments in road accidents and injury patterns of vulnerable road users, established test and assessment procedures need to be continuously verified and, where needed, to be revised. The demographic change as well as changes in the vehicle fleet, leading to a variation of accident scenarios, injury frequencies and injury patterns of vulnerable road users are addressed by the work provided by the SENIORS project, introducing updated impactors for pedestrian test and assessment procedures.
A reduction of around 48% of all road fatalities was achieved in Europe in the past years including a reduced number of fatalities with an older age. However, among all road fatalities, the proportion of elderly is steadily increasing. In an ageing society, the European (Horizon2020) project SENIORS aims to improve the safe mobility of older road users, who have different transportation habits compared to other age groups. To increase their level of safe mobility by determining appropriate requirements for vehicle safety systems, the characteristics of current road traffic collisions involving the elderly and the injuries that they sustain need to be understood in detail. Hereby, the paper focuses on their traffic participation as pedestrian, cyclist or passenger car occupant. Following a literature review, several national and international crash databases and hospital statistics have been analysed to determine the body regions most frequently and severely injured, specific injuries sustained and types of crashes involved, always comparing older road users (65 years and more) with mid-aged road users (25-64 years). The most important crash scenarios were highlighted. The data sources included European statistics from CARE, data on national level from Germany, Sweden, Italy, United Kingdom and Spain as well as in-depth crash information from GIDAS (Germany), RAIDS (UK), CIREN and NASS-CDS (US). In addition, familiar hospital data from Germany (TraumaRegister DGU-®), Italy (Italian Register of Acute Traumas) and UK hospital statistics (TARN) were included in the study to gain further insight into specific injury patterns. Comprehensive data analyses were performed showing injury patterns of older road users in crashes. When comparing with mid-aged road users, all databases showed that the thorax body region is of particularly high importance for the older car occupant with injury severities of AIS 2 or AIS 3+, whereas the body regions lower extremities, head and thorax need to be considered for the older pedestrians and cyclists. Besides these comparisons, the most frequent and severe top 5 injuries were highlighted per road user group. Further, the most important crash configurations were identified and injury risk functions are provided per age group and road user group. Although several databases have been analysed, the picture on the road safety situation of older road users in Europe was not complete, as only Western European data was available. The linkage between crash data and hospital data could only be made on a general level as their inclusion criteria were quite different.
Risk-based approach for the protection of land transport infrastructure against extreme rainfall
(2016)
The aim of the research project "Risk based approach for the protection of transport infrastructure against extreme rainfall RAINEX" is the development of a practical methodology for the identification and assessment of both vulnerable as well as critical transport infrastructures towards extreme rainfall events consequences. The developed methodology is based on expert knowledge and includes qualitative and semi-quantitative analyses regarding the assessment of the vulnerability and criticality of relevant transport infrastructures. The process chain from the spatial rainfall to the concentrated runoff in the river channel was shown to assess the local hazard resulting in the local risk. The main result of the project is a practice-oriented and applicable methodology and a comprehensive and well-developed security handbook.
Supported by field accident data and monitoring results of European Regulation (EC) No. 78/2009, recent plans of the European Commission regarding a way forward to improve passive safety of vulnerable road users include, amongst other things, an extension of the head test area. The inclusion of passive cyclist safety is also being considered by Euro NCAP. Although passenger car to cyclist collisions are often severe and have a significant share within the accident statistics, cyclists are neither considered sufficiently in the legislative nor in the consumer ratings tests. Therefore, a test procedure to assess the protection potential of vehicle fronts in a collision with cyclists has been developed within a current research project. For this purpose, the existing pedestrian head impact test procedures were modified in order to include boundary conditions relevant for cyclists as the second big group of vulnerable road users. Based on an in-depth analysis of passenger car to cyclist accidents in Germany the three most representative accident constellations have been initially defined. The development of the test procedure itself was based on corresponding simulations with representative vehicle and bicycle models. In addition to different cyclist heights, reaching from a 6-year-old child to a 95%-male, also four pedal positions were considered. By reconstruction of a real accident the defined simulation parameters could be validated in advance. The conducted accident kinematics analysis shows for a large portion of the constellations an increased head impact area, which can reach beyond the roof leading edge, as well as high average values for head impact velocity and angle. Based on the simulation data obtained for the different vehicle models, cyclist-specific test parameters for impactor tests have been derived, which have been further examined in the course of head and leg impact tests. In order to study the cyclist accident kinematics under real test conditions, different full scale tests with a Polar-II dummy positioned on a bicycle have been conducted. Overall, the tests showed a good correlation with the simulations and support the defined boundary test conditions. Typical accident scenarios and simulations reveal higher head impact locations, angles and velocities. An extended head impact area with modified test parameters will contribute to an improved protection of vulnerable road users including cyclists. However, due to significantly differing impact kinematics and postures between the lower extremities of pedestrians and cyclists, these injuries cannot be addressed by the means of current test tools such as the flexible pedestrian legform impactor FlexPLI. Based on the findings obtained within the project as well as the existing pedestrian protection requirements a cyclist protection test procedure for use in legislation and consumer test programmes has been developed, whose requirements have been transferred into a corresponding test specification. This specification provides common head test boundary conditions for pedestrians and cyclists, whereby the existing requirements are modified and two parallel test procedures are avoided.
According to the German road traffic regulations children up to the age of 12 or a height below 150 cm have to use approved and appropriate child restraint systems (CRS). CRS must be approved according to UN-ECE Regulation No. 44. The regulation classifies CRS in 5 weight categories. The upper weight group is approved for children from 22 to 36 kg. However, studies show that already today many children weigh more than 36 kg although they have not reached a height of 150 cm. Therefore, no ECE R44 approved CRS is available for these overweight children. In conclusion, today's sizes and weights of children are no longer represented by the current version of the ECE R44. The heaviest used dummy (P10) weighs just 32.6 kg and has a height of 137.9 cm. Statistical data of German children show that already 5% of the children at a height of 137.9 cm have a weight above 45.3 kg. Regarding children at a height of 145 cm, the 95th percentile limit is at a weight of 53.3 kg. Based on these data 4 dummies with different heights and weights were defined and produced. Two of them are overweight. Up to now, there is no experience how current child restraint systems perform in a car crash if they are used by children with a weight above 36 kg and a height smaller than 150 cm. In the future, different child restraint systems will be tested with respect to the ECE R44 regulation using these overweight dummies.
The use of proper child restraint systems (CRS) is mandatory for children travelling in cars in most countries of the world. The analysis of the quantity of restrained children shows that more than 90% of the children in Germany are restrained. Looking at the quality of the protection, a large discrepancy between restrained and well protected children can be seen. Two out of three children in Germany are not properly restrained. In addition, considerable difference exists with respect to the technical performance of CRS. For that reason investigations and optimisations on two different topics are necessary: The technical improvement of CRS and the ease of use of CRS. Consideration of the knowledge gained by the comparison of different CRS in crash tests would lead to some improvements of the CRS. But improvement of child safety is not only a technical issue. People should use CRS in the correct way. Misuse and incorrect handling could lead to less safety than correct usage of a poor CRS. For that reason new technical issues are necessary to improve the child safety AND the ease of use. Only the combination of both parts can significantly increase child safety. For the assessment of the safety level of common CRS, frontal and lateral sled tests simulating different severity levels were conducted comparing pairs of CRS which were felt to be good and CRS which were felt to be poor. The safety of some CRS is currently at a high level. All well known products were not damaged in the performed tests. The performance of non-branded CRS was mostly worse than that of the well known products. Although the branded child restraint systems already show a high safety level it is still possible to further improve their technical performance as demonstrated with a baby shell and a harness type CRS.
Proposal for a test procedure of assistance systems regarding preventive pedestrian protection
(2011)
This paper is showing a proposal for a test procedure regarding preventive pedestrian protection based on accident analysis. Over the past years pedestrian protection has become an increasing importance also during the development phase of new vehicles. After a phase of focusing on secondary safety, there are current activities to detect a possible collision by assistance systems. Such systems have the task to inform the driver and/or automatically activate the brakes. How practical is such a system? In which kind of traffic situations will it work? How is it possible to check the effectiveness of such a system? To test the effectiveness, currently there are no generally approved identifiable procedures. It is reasonable that such a test should be based on real accidents. The test procedure should be designed to test all systems, independent of the system- working principle. The vFSS group (advanced Forward-looking Safety Systems) was founded to develop a proposal for a technology independent test procedure, which reflects the real accident situation. This contribution is showing the results of vFSS. The developed test procedure focuses on accidents between passenger cars and pedestrians. The results are based on analysis results of in-depth databases of GIDAS, German insurers and DEKRA and added by analysis of national and international statistics. The in-depth analysis includes many pre-crash situations with several influencing factors. The factors are e. g. speed of the car, speed of the pedestrian, moving direction and a possible obscuration of the pedestrian by an object. The results comprise also the different situations of adults and children. Furthermore, they include details regarding influence of the lighting conditions (daylight or night) especially with respect to the accident consequences. In fact, more accidents happen at daylight, but fatal accidents are more often at night. A clustering of parameter combinations was found which represents typical accident scenarios. There are six typical accident scenarios which were merged in four test scenarios. The test scenarios are varying the starting position of the pedestrian, the pedestrian size (adult or child) and the speed of the pedestrian, whereas the speed of the car will not be varied. To ensure the independency from used sensing technologies it is necessary to use a suitable dummy. For example, if sensors are based on infrared, the dummy should emit the temperature of a human being. The test procedure will identify the collision speed as the key parameter for assessing the effectiveness of the tested system. The collision speed is defined as the reduction between initial test speed of the car and impact speed. The assessment of the speed reduction value regarding the safety benefit, however, will be part of a separate procedure.