Identification of vehicle rollover conditions and active roll control strategies

Abstract

This research presents the development of active roll control strategies to prevent vehicle rollover. The dynamic model representing the vehicle behaviour was first developed and then modelled in Matlab/SIMULINK environment. The tire model integrated to the vehicle model was represented using look up table method. The validity of the vehicle model was verified using CarSim software for double lane change and fishhook manoeuvres. The validation results show strong agreement between the vehicle model and CarSim software. Parametric study was done to investigate the effect of the driver inputs and vehicle parameters on the roll behavior of the vehicle. The effect of the variation of these properties on the vehicle roll angle and load transfer ratio was discussed. Two fuzzy logic based active roll control schemes were developed using active suspension and active front steering. For active roll control using active suspension, the effectiveness of feedforward fuzzy and combination of feedback and feedforward fuzzy in reducing the rollover propensity were evaluated. For active front steering, feedback fuzzy control was incorporated with the vehicle model to assess the performance of the active front steering in reducing vehicle rollover propensity for fishhook and step steer manoeuvres. Both of the proposed control strategies had shown significant enhancement in avoiding vehicle rollover and hence improving the safety of vehicle occupants.