RESUMO
Objective: Vehicle collisions are described with the help of collision severity parameters such as energy equivalent speed (EES) and the collision-based change of velocity (delta-v). These serve as an input for injury outcome estimations through injury risk functions (IRF) or for the virtual assessment of active safety systems in case of a modified collision. A novel method was developed with the aim of simulating various vehicle collisions within a short time frame while ensuring the accuracy of the collision severity parameters.Methods: Previously developed three-dimensional EES models were used in this study. They were used to compute 2 D vehicle substitute models, which are deformed during a new, time-discrete method. By using fundamentals of mechanical impact calculation and vehicle kinematics, relevant collision severity parameters are calculated. These steps are executed in an own developed standalone tool named impactEES. The results obtained were verified against measured crash test data from the European New Car Assessment Programme (Euro NCAP) and the Technical Center of Allgemeiner-Deutscher-Automobil-Club (ADAC).Results: The novel method enables the automated computation of various car-to-car and car-to-object collisions. The output of impactEES includes the deformation area, EES, and delta-v. Furthermore, it includes the following time-discrete data for each vehicle: translational and angular accelerations, translational and angular velocities, and the position of the center of gravity in addition to the heading of the vehicle. Finally, without the need of highly sophisticated hardware, a single simulation of a collision between two vehicles can be calculated within only a few seconds including collision severity parameters. Based on the comparison of measured crash test data and results obtained from impactEES the mean percentage error (MPE) and its standard deviation (SD) were calculated for EES (MPE= - 2.0%, SD = 8.4%, n = 14) and delta-v (MPE= - 1.2%, SD = 14.2%, n = 18).Conclusions: The novel method allows for the 2 D computation of various car-to-car and car-to-object collisions. Using predefined IRF allows the assessment of injury probabilities relative to the change of collision severity parameters. Both can be used for the virtual assessment of injury mitigation capabilities of active safety systems and thus represent an important contribution to its targeted development.
Assuntos
Acidentes de Trânsito , Ferimentos e Lesões , Humanos , Acidentes de Trânsito/prevenção & controle , Simulação por Computador , Aceleração , Fenômenos Biomecânicos , ProbabilidadeRESUMO
BACKGROUND: Due to a constantly increasing life expectancy and the need to stay mobile at a high age, the proportion of over 65-year-olds in traffic accidents is increasing from year to year. METHOD: In order to identify potentials for increasing the safety of seniors in road traffic, accident data were analyzed with respect to the categories of road users and accident types of this age group. Based on the accident data analysis, active and passive safety systems are described that could increase the road safety particular for senior citizens. RESULTS: It was found that older road users are frequently involved in accidents as car occupants, cyclists and pedestrians. In addition, car drivers and cyclists aged 65 years and older are frequently involved in driving, turning and crossing accidents. Lane departure warning and emergency braking assistants have a high potential for accident avoidance as they can defuse critical situations at the last moment. Restraint systems (airbags, seat belts) adapted to physical characteristics could minimize the severity of injuries to older car occupants.
