Pedestrian kinematics:​ a detailed study from the AsPeCSS project

Rodarius, Carmen; de Hair, Stefanie; Mottola, Ernesto; Schaub, Swen

Affiliations

Abstract

This study aims at providing insight on pedestrian kinematics during vehicle impact for the following variables: pedestrian size, position and posture as well as vehicle related variables like shape, speed and pre-crash braking. It is part of the work conducted within work package 3 “Injury assessment: data for construction of injury risk curves” of the European project “Assessment methodologies for forward looking Integrated Pedestrian and further extension to Cyclists Safety Systems” (AsPeCSS). The results of this subtask are used within the project to adapt current testing procedures towards more realistic approaches based on changes introduced into accident circumstances by todays smarter car designs.

First, a trend study was carried out using simplified vehicle models based on “Advanced PROtection SYStems” (APROSYS) work in MADYMO using the MADYMO ellipsoid human body models. In a second step, different detailed finite element (FE) and multi body (MB) vehicle models of recent cars were investigated using MADYMO and the MADYMO facet pedestrian model as well as LSDyna and the “Total Human Model for Safety” (THUMS) human body models.

Approximately 1700 different simulations were done to study the general effect on head impact speed, angle and wrap around distance (WAD) when varying input parameters like vehicle shape and speed but also pedestrian size, postures and orientations towards the car.

The second study confirmed the trends found with the simplified car models and provided more detailed information on the head and upper leg impact conditions. Moreover, some general effects introduced by simplified models were evaluated and corrected using the results of the detailed vehicle studies. Additional parameter variations as pitching and braking of the car for different initial speeds or lateral impact position provide a complete picture of pedestrian impact kinematics. It was found, that not only vehicle speed and pedestrian size determined how and where the head of the pedestrian hits the car but also differences in posture or vehicle pitching due to pre-crash braking are influencing the kinematics, the impact conditions as well as the potential injury risk significantly. A running child can hence for example hit a car differently than a walking one. Also, significant differences were found depending on whether the head impact occurs on a bonnet top or the windscreen area.

Combining all three simulation studies the influence of active safety systems on the pedestrian kinematics during car to pedestrian impacts has been estimated. The combined use of generic and actual car models leads to results that are valid for the current and future vehicle fleet. Information on pedestrian kinematics is needed to propose updates to current pedestrian regulations and consumer tests in line with the development of integrated safety systems.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv23/23ESV-000410.pdf

Cited Works (7)

Year	Entry
2009	Kerrigan J, Arregui C, Crandall J. Pedestrian head impact dynamics: comparison of dummy and PMHS in small sedan and large SUV impacts. In: Proceedings of the 21st International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 15-18, 2009; Stuttgart, Germany.
2012	Meijer R, van Hassel E, Broos J, Elrofai H, van Rooij L, van Hooijdonk P. Development of a multi‐body human model that predicts active and passive human behaviour. In: Proceedings of the 2012 International IRCOBI Conference on the Biomechanics of Injury. September 12-14, 2012; Dublin, Ireland.622-636.
2005	Snedeker JG, Walz FH, Muser MH, Lanz C, Schroeder G. Assessing femur and pelvis injury risk in car‐pedestrian collisions: comparison of full body PMTO impacts, and a human body finite element model. In: Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 6-9, 2005; Washington, DC.
2003	Van Hoof J, De Lange R, Wismans JSHM. Improving pedestrian safety using numerical human models. Stapp Car Crash J. 2003;47:401-436. SAE 2003-22-0018.
2007	Masson C, Serre T, Cesari D. Pedestrian-vehicle accident: analysis of 4 full scale tests with PMHS. In: Proceedings of the 20th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 18-21, 2007; Lyon, France.
2008	Kerrigan JR, Crandall JR, Deng B. A comparative analysis of the pedestrian injury risk predicted by mechanical impactors and post mortem human surrogates. Stapp Car Crash J. 2008;52:527-567. SAE 2008-22-0020.
2012	Watanabe R, Katsuhara T, Miyazaki H, Kitagawa Y, Yasuki T. Research of the relationship of pedestrian injury to collision speed, car-type, impact location and pedestrian sizes using human FE model (THUMS Version 4). Stapp Car Crash J. October 2012;56:269-321.