Analysis of a Dual Occupant Ejection Scenario Utilising Design of Experiments and Multi-objective Optimisation Techniques

摘要

Collision reconstruction aims to represent the physics of vehicle dynamics and structures, alongwith driver input and occupant biomechanics, using a range of tools from simple physics calculationsthrough to complex mathematical models. While vehicle design is increasingly Computer AidedEngineering (CAE) driven, the advanced modelling methods developed for CAE are not necessarilystraightforward to employ in general collision reconstruction. CAE models are often dedicated tospecific (laboratory) test conditions for pre-impact driving or purely for impact, while collision reconstructionoften addresses complex real world cases requiring integrated simulation of pre-crash andcrash events. Furthermore vehicle and restraint models developed for design may not be accessible tocollision investigators.The paper describes the recent development in our CAE simulation methodology: the use of DOE(Design of Experiments) and Multi-Objective Optimisation techniques together with MADYMO modellingin order to generate an understanding of a complex real world collision scenario. This case studyinvolves a dual ejection single vehicle incident which was investigated by Advanced Simtech in theUK for Avon and Somerset Police during 2007. There was insufficient data to allow the case to besolved using other well-established police methods but our methodology and toolsets allowed the incidentto be successfully reconstructed, securing a conviction as a direct result of our analysis. Thereconstruction was conducted in two separate phases. The purpose of the first phase was to obtain anaccurate motion for the vehicle during the event, using a vehicle dynamics reconstruction simulationthat was correlated to the physical evidence and tyre markings left at the scene. This was followedby an occupant analysis phase which focussed on the opportunity of ejection for the people involved.Both phases incorporate DOE techniques allowing us to fully understand the effect and influence ofeach of the input parameters involved.