Mathematical Modelling and Analysis of Vehicle Frontal Crash using Lumped Parameters Models

A full-scale crash test is conventionally used for vehicle crashworthiness analysis. However, this approach is expensive and time-consuming. Vehicle crash reconstructions using different numerical modelling approaches can predict vehicle behavior and reduce the need for multiple full-scale crash tests, thus research on the crash reconstruction has received a great attention in the last few decades. Among modelling approaches, lumped parameters models (LPM) and finite element models (FEM) are commonly used in the vehicle crash reconstruction. This thesis focuses on developing and improving the LPM for vehicle frontal crash analysis. The study aims at reconstructing crash scenarios for vehicle-to-barrier (VTB), vehicleoccupant (V-Occ), and vehicle-to-vehicle (VTV), respectively. In this study, a single mass-spring-damper (MSD) is used to simulate a vehicle to-barrier or a wall. A double MSD is used to model the response of the chassis and passenger compartment in a frontal crash, a vehicle-occupant, and a vehicle-tovehicle, respectively. A curve fitting, state-space, and genetic algorithm are used to estimate parameters of the model for reconstructing the vehicle crash kinematics. Further, the piecewise LPM is developed to mimic the crash characteristics for VTB, VO, and VTV crash scenarios, and its predictive capability is compared with the explicit FEM. Within the framework, the advantages of the proposed methods are explained in detail, and suggested solutions are presented to address the limitations in the study.publishedVersio

Systems modelling and ethical decision algorithms for autonomous vehicle collisions

A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of Philosophy.There has been an increasing interest in autonomous vehicles (AVs) in recent years. Through the use of advanced safety systems (ASS), it is expected that driverless AVs will result in a reduced number of road traffic accidents (RTAs) and fatalities on the roads. However, until the technology matures, collisions involving AVs will inevitably take place. Herein lies the hub of the problem: if AVs are to be programmed to deal with a collision scenario, which set of ethically acceptable rules should be applied? The two main philosophical doctrines are the utilitarian and deontological approaches of Bentham and Kant, with the two competing societal actions being altruistic and selfish as defined by Hamilton. It is shown in simulation, that the utilitarian approach is likely to be the most favourable candidate to succeed as a serious contender for developments in the programming and decision making for control of AV technologies in the future. At the heart of the proposed approach is the development of an ethical decision-maker (EDM), with this forming part of a model-to-decision (M2D) approach. Lumped parameter models (LPMs) are developed that capture the key features of AV collisions into an immovable rigid wall (IRW) or another AV, i.e. peak deformation and peak acceleration. The peak acceleration of the AV is then related to the accelerations experienced by the occupant(s) on-board the AV, e.g. peak head acceleration. Such information allows the M2D approach to decide on the collision target depending on the selected algorithm, e.g. utilitarian or altruistic. Alongside the EDM is an active collision system (ACS) which is able to change the AV structural stiffness properties. The ACS is able to compensate for situations when AVs are predicted to experience potentially severe and fatal injury severity levels