Influence of Reversible, Variable Safety-regarding Parameters on Injury Severity

With the advent of more computational power in motor vehicles innovative vehicle-functions like the autonomous driving function get close to find use. Besides a higher degree of freedom for the occupant that arises from autonomous driving functions, also the occupant safety might be addressed by future innovative and adaptive vehicle functions. In this context the posture of the occupant and the adjustment of the seat are identified to influence the injury severity level in case of a motor vehicle crash. However, the field of research on the influence of these reversible and variable safety-regarding parameters leaves untapped potential for further investigations. Therefore, the present work investigates the influence of the seating posture and seat adjustment on the injury severity outcome in case of a crash by means of a hybrid data base approach. Thereby, the conducted analyses on the influence of reversible and variable safety regarding parameters are performed in at least three (HFN: Head/ Face/ Neck, Thorax, PHL: Pelvis/ Hip/ Lower Extremities) up to five (Abdomen, Upper Extremities) body regions. Thus, on the one hand the present work is among the first to evidence the respective influence based on real-world crash data. Using data from the German In Depth Accident Study (GIDAS) the calculated odds ratios reveal a high influence of the seat recline on the injury outcome on whole body level as well as in in all five investigated body regions. On the other hand, simulation-based data is analyzed to illustrate relative risks with reference to a normal posture and seat adjustment. These range from factors of almost 0 to factors of about 50 (KTH fracture risk in an oblique crash constellation after [RFK10]). In addition, based on the simulation-based data, models for an injury severity estimation on occupant level in dependence on the investigated parameters are generated. With the aid of these models it can be shown, that the investigated frontal crash constellations lead to different model behaviours and thus must be considered. Furthermore, it becomes clear, that the complexity of the model behaviours in the investigated parameter space pose a challenge for the application in a real-world vehicle function. An overall view on the conducted analyses allows for a comprehensive overview on the basis of different data types. In general the most affected body region is the PHL region, followed by the HFN and finally the Thorax body region. The interdisciplinary analyses performed in the present work lead to results that give a fundamental understanding of the influences of seat adjustment and seating posture of the occupant in case of a motor vehicle crash. Besides the danger of worsening the injury severity outcome by an alteration of the seat adjustment and seating posture it also offers a huge potential for mitigation of the injury severity in single body regions. Furthermore, the consideration of the occupant within crash-relevant innovative vehicle functions is shown to be crucial which for the development of future innovative and adaptive safety systems is highly recommended to be taken into account.