Modeling of rollover sequences

摘要

Safety restraint systems greatly reduce the potential injury risk during vehicle accidents. One major type of accident still remains without adequate occupant protection: Vehicle Rollover. Since rollover experiments are difficult to perform, rollover models can help to understand this type of accident. It will be shown, that already quite simple models reveal important properties of vehicle rollover. The influence of various parameter variations can be investigated. Based on a simplified modeling approach, it is possible to develop an analytic stability boundary, which helps to detect an imminent rollover. This is the base for future occupant protection systems. A more complete and complex approach of modeling, covering e.g. half and full turns, requires different strategies. To include detailed suspension systems a multi body approach becomes necessary. As an arbitrary rollover is a fully spatial movement, special assumptions like wheel-road contact do not hold for the regarded time interval. To cope with these difficulties, the simulation requires a state space machine to cover the different vehicle conditions (road contact, free flight, one side lift off). The simulation can then switch between the different model structures. With this approach, classical multi-body vehicle models can be extended by special rollover models to gain insight in the mechanisms causing vehicle rollover.