Rollover prevention control using integrated rollover index based on model prediction

Abstract

The purpose of this study is to estimate the vehicle parameters for rollover control, present an integrated rollover index and rollover control scheme to mitigate the vehicle rollover. Vehicle mass is considered to be a constant parameter for other vehicle safety controls, but it changes according to the number of the passengers or the load weight the vehicle carries. The roll inertia and C.G. height are also variable parameters according to the vehicle mass or the other factors. A rollover index which indicates an impending rollover possibility is developed from an energy index and a phase plane index using the model prediction of the vehicle states. The integrated rollover index takes the advantages of the energy method and the phase plane method for the early but accurate control. The tire force estimators calculate the present vertical, longitudinal and lateral tire forces to determine the maximum available tire force using the tire friction circle to prevent the excessive braking forces. The rollover control scheme is designed to use differential braking forces considering the vehicle side slip angle, yaw rate, roll rate and roll angle. The proposed rollover control algorithm is evaluated via simulation using CarSim and Simulink and via experimentation using a test vehicle. Simulation and experiment results demonstrate the proposed algorithm detects and controls the vehicle rollover efficiently with significantly reduced false activation of the brake.