Abteilung Fahrzeugtechnik
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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.
Für eine Reihe von EU Regelungen im Bereich Fahrzeugsicherheit erlaubt eine Verordnung bereits seit dem Jahr 2010 virtuelles Testen für die Typzulassungsprüfung. Technische Details bzw. konkrete Prozeduren für spezifische Regelungen sind in dieser Verordnung jedoch nicht enthalten. Das Hauptziel des europäischen Projekts IMVITER (lmplementation of Virtual Testing in Safety Regulations) war es, basierend auf der neuen Verordnung ein virtuelles Testverfahren auszuarbeiten und dabei offene Fragen zu berücksichtigen. Um die im Projekt-Konsortium unter Berücksichtigung der Anliegen aller Interessensgruppen wie Autohersteller, Zulassungsbehörden und technischer Dienste erarbeiteten offenen Punkte zu adressieren, wurde ein generisches Flussdiagramm entwickelt, das den Ablauf einer virtuell basierten Typprüfung darstellt. ln diesem Diagramm ist der virtuelle Typgenehmigungsprozess in drei aufeinander folgende Phasen aufgeteilt, die Verifikations-, Validierungs- und Typgenehmigungsphase. Von entscheidender Bedeutung ist die Phase der Validierung des Simulationsmodells, für die im IMVITER-Projekt eine Methodik vorgeschlagen wurde. Mit der im Projekt vorgeschlagenen Validierungsmethode ist kein Austausch des Simulationsmodells zwischen Fahrzeughersteller und technischem Dienst notwendig, so dass die Vertraulichkeit von Betriebsgeheimnissen nicht gefährdet ist. Zur Validierung des Modells werden jedoch immer Versuche notwendig sein. Dies gilt sowohl für die Überpruefung von passiven als auch aktiven Fahrzeugsicherheitssystemen. Eine zusammenfassende Betrachtung der Erfahrungen aus dem IMVITER-Projekt ergab, dass mit der Einführung von virtuellem Testen keine Erhöhung der Anforderungen an die Fahrzeugsicherheit bzgl. bestehender Regelungen verbunden sein sollte. Jedoch werden auch weiterhin neue zusäztliche Regelungen erforderlich sein, da sich das Unfallgeschehen und die Fahrzeugtechnologie weiterentwickeln und ändern werden. Diese sollten von Beginn an die Möglichkeiten des virtuellen Testens nutzen, insbesondere bei Testverfahren für neue Technologien, z.B. aktiver Fahrzeugsicherheitssysteme. Hier bieten virtuelle Testverfahren nicht nur eine Kosten- oder Zeitersparnis, sondern ermöglichen teilweise erst die sinnvolle Abprüfung von neuen Sicherheitssystemen, die mit aktuellen auf Hardware-Test basierenden Verfahren überhaupt nicht möglich wären.
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.
A legform impactor with biofidelic characteristics (FlexPLI) which is being developed by the Japanese Automobile Research Institute (JARI) is being considered as a test tool for legislation within a proposed Global Technical Regulation on pedestrian protection (UNECE, 2006) and therefore being evaluated by the Technical Evaluation Group (TEG) of GRSP. In previous built levels it already showed good test results on real cars as well as under idealised test conditions but also revealed further need for improvement. A research study at the Federal Highway Research Institute (BASt) deals with the question on how leg injury risks of modern car fronts can be revealed, reflected and assessed by the FlexPLI and how the impactor can be used and implemented as a legislative instrument for the type approval of cars according to current and future legislations on pedestrian protection. The latest impactor built level (GTα ) is being evaluated by a general review and assessment of the certification procedure, the knee joint biofidelity and the currently proposed injury criteria. Furthermore, the usability, robustness and durability as a test tool for legislation is examined and an assessment of leg injuries is made by a series of tests with the FlexPLI on real cars with modern car front shapes as well as under idealised test conditions. Finally, a comparison is made between the FlexPLI and the current european legislation tool, the legform impactor according to EEVC WG 17.
A means of assessing the passive safety of automobiles is a desirable instrument for legislative bodies, the automobile industry, and the consumer. As opposed to the dominating motor vehicle assessment criteria, such as engine power, spaciousness, aerodynamics and consumption, there are no clear and generally accepted criteria for assessing the passive safety of cars. The proposed method of assessment combines the results of experimental safety tests, carried out according to existing legally prescribed or currently discussed testing conditions, and a biomechanical validation of the loading values determined in the test. This evaluation is carried out with the aid of risk functions which are specified for individual parts of the body by correlating the results of accident analysis with those obtained by computer simulation. The degree of conformance to the respective protection criterion thus deduced is then weighted with factors which take into account the frequency of occurrence and the severity of the accident on the basis of resulting costs. Each of the test series includes at least two frontal and one lateral crash test against a deformable barrier. The computer-aided analysis and evaluation of the simulation results enables a vehicle-specific overall safety index as well as partial and individual safety values to be determined and plotted graphically. The passive safety provided by the respective vehicle under test can be defined for specific seating positions, special types of accident, or for individual endangered parts of the body.
The off-set assessment procedure potentially contributes to the FIMCAR objectives to maintain the compartment strength and to assess load spreading in frontal collisions. Furthermore it provides the opportunity to assess the restraint system performance with different pulses if combined with a full-width assessment procedure in the frontal assessment approach. Originally it was expected that the PDB assessment procedure would be selected for the FIMCAR assessment approach. However, it was not possible to deliver a compatibility metric in time so that the current off-set procedure (ODB as used in UNECE R94) with some minor modifications was proposed for the FIMCAR Assessment Approach. Nevertheless the potential to assess load spreading, which appears not to be possible with any other assessed frontal impact assessment procedure was considered to be still high. Therefore the development work for the PDB assessment procedure did not stop with the decision not to select the PDB procedure. As a result of the decisions to use the current ODB and to further develop the PDB procedure, both are covered within this deliverable. The deliverable describes the off-set test procedure that will be recommended by FIMCAR consortium, this corresponds to the ODB test as it is specified in UN-ECE Regulation 94 (R94), i.e. EEVC deformable element with 40% overlap at a test speed of 56 km/h. In addition to the current R94 requirements, FIMCAR will recommend to introduce some structural requirements which will guarantee sufficiently strong occupant compartments by enforcing the stability of the forward occupant cell. With respect to the PDB assessment procedure a new metric, Digital Derivative in Y direction - DDY, was developed, described, analysed, and compared with other metrics. The DDY metric analyses the deformation gradients laterally across the PDB face. The more even the deformation, the lower the DDY values and the better the metric- result. In order analyse the different metrics, analysis of the existing PDB test results and the results of the performed simulation studies was performed. In addition, an assessment of artificial deformation profiles with the metrics took place. This analysis shows that there are still issues with the DDY metric but it appears that it is possible to solve them with future optimisations. For example the current metric assesses only the area within 60% of the half vehicle width. For vehicles that have the longitudinals further outboard, the metric is not effective. In addition to the metric development, practical issues of the PDB tests such as the definition of a scan procedure for the analysis of the deformation pattern including the validation of the scanning procedure by the analysis of 3 different scans at different locations of the same barrier were addressed. Furthermore the repeatability and reproducibility of the PDB was analysed. The barrier deformation readings seem to be sensitive with respect to the impact accuracy. In total, the deliverable is meant to define the FIMCAR off-set assessment procedure and to be a starting point for further development of the PDB assessment procedure.
Es wird über das Ende 2002 abgeschlossene EU-Projekt ADVISORS berichtet. Ziel dieses Projektes, an dem sich 16 Organisationen aus 10 europäischen Ländern beteiligten, war es, die Entwicklung, Testung und Implementierung von Fahrerassistenzsystemen (FAS) zu unterstützen. Es wurde eine umfassende Methodik zur Bewertung von FAS entwickelt und auf dieser Basis wurden eine Reihe von Evaluationsstudien zu ausgewählten FAS durchgeführt. Des Weiteren wurden Implementierungsstrategien für bestimmte FAS entwickelt und mit Experten verschiedener Länder diskutiert.
The objective of this deliverable is to describe the expected influence of the candidate test procedures developed in FIMCAR for frontal impact on other impact types. The other impact types of primary interest are front-to-side impacts, collisions with road restraint systems (e.g. guardrails), and heavy goods vehicle impacts. These collision types were chosen as they involve structures that can be adapted to improve safety. Collisions with vulnerable road users (VRU) were not explicitly investigated in FIMCAR. It is expected that the vehicle structures of interest in FIMCAR can be designed into a VRU friendly shell. Information used for this deliverable comes from simulations and car-to-car crash tests conducted in FIMCAR or review of previous research. Three test configurations (full width, offset, and moving deformable barriers) were the input to the FIMCAR selection process. There are three different types of offset tests and two different full width tests. During the project test procedures could be divided into three groups that provide different influences or outcomes on vehicle designs: 1. The ODB barrier provides a method to assess part of the vehicles energy absorption capabilities and compartment test in one test. 2. The FWRB and FWDB have similar capabilities to control structural alignment, further assess energy absorption capabilities, and promote the improvements in the occupant restraint system for high deceleration impacts. 3. The PDB and MPDB can be used to promote better load spreading in the vehicle structures, in addition to assessing energy absorption and occupant compartment strength in an offset configuration. The consortium selected the ODB and FWDB as the two best candidates for short term application in international rulemaking. The review of how all candidates would affect vehicle performance in other impacts (beside front-to-front vehicle or frontal impacts with fixed obstacles) however is reported in this deliverable to support the benefit analysis reported in FIMCAR. The grouping presented above is used to discuss all five test candidates using similarities between certain tests and thereby simplify the discussion.
A flexible pedestrian legform impactor (FlexPLI) has been evaluated by a Technical Evaluation Group (Flex-TEG) of the Working Party on Passive Safety (GRSP) of the United Nations Economic Commission for Europe (UN-ECE). It will be implemented within phase 2 of the global technical regulation (GTR 9) as well as within a new ECE regulation on pedestrian safety as a test tool for the assessment of lower extremity injuries in lateral vehicle-to-pedestrian accidents (UN-ECE 2010-1, 2010-2 and 2010-3). Due to its biofidelic properties in the knee and tibia section, the FlexPLI is found to having an improved knee and tibia injury assessment ability when being compared to the current legislative test tool, the lower legform impactor developed by the Pedestrian Safety Working Group of the European Enhanced Vehicle-safety Committee (EEVC WG 17). However, due to a lack of biofidelity in terms of kinematics and loadings in the femur part of the FlexPLI, an appropriate assessment of femur injuries is still outstanding. The study described in this paper is aimed to close this gap. Impactor tests with the FlexPLI at different impact heights on three vehicle frontends with Sedan, SUV and FFV shape are performed and compared to tests with a modified FlexPLI with upper body mass. Full scale validation tests using a modified crash test dummy with attached FlexPLI that are carried out for the first time prove the more humanlike responses of the femur section with applied upper body mass. Apart from that they also show that the impact conditions described in the current technical provisions for tests with the FlexPLI don"t necessarily compensate the missing torso mass in terms of knee and tibia loadings either. Therefore it can be concluded that an applied upper body mass will contribute to a more biofidelic overall behavior of the legform and subsequently an improved injury assessment ability of all lower extremity injuries addressed by the FlexPLI. Nevertheless, the validity of the original as well as the modified legform for tests against vehicles with extraordinary high bumpers as well as flat front vehicles still needs to be evaluated in detail. A first clue is given by the application of an additional accelerometer to the legform.
Am 01.03.2004 wurde auf europäischer Ebene das Expertennetzwerk HUMANIST (HUMAN centred design for Information Society Technologies) eingerichtet, das sich mit Fragen der Implementierung, Gestaltung und Evaluation von Fahrerassistenz- und -informationssystemen aus einer sicherheits- und nutzerorientierten Perspektive befasst. Insgesamt sind 26 Partnerorganisationen aus 15 europäischen Ländern beteiligt. Nach bisher zwei Jahren Laufzeit kann das Netzwerk eine Vielzahl von erfolgreich durchgeführten Veranstaltungen vorweisen (verschiedene werden im Einzelnen aufgeführt). Darüber hinaus wurde ein Post-Graduierten- beziehungsweise ein Post-Doc-Programm ins Leben gerufen. Eine weitere wichtige Initiative bestand in der Beschaffung von Grundlagen für eine gemeinsame Nutzung der bei den beteiligten Partnern vorhandenen Forschungs-Infrastruktur und einer gemeinsam genutzten Datenbasis und virtuellen Arbeitsumgebung. Weiterhin konnten auch wissenschaftliche Ergebnisse erarbeitet werden, die in einigen wesentlichen Ausschnitten dargestellt werden. Dabei handelt es sich um folgende Themen: Nutzerbedürfnisse und Potenziale von Fahrerassistenz- und -informationssystemen; Auswirkung der Nutzung von Fahrerassistenz- und -informationssystemen auf das Fahrverhalten und ihre methodische Erfassung; Fahrerausbildung für die Nutzung von Fahrerassistenz- und -informationssystemen. Abschließend wird auf die im Jahr 2006 geplanten Aktivitäten hingewiesen.