Abstract
The heavy-duty commercial vehicles, which have wide range of applications, call for better ride comfort and driving stability more and more urgently in recent years. Because heavyduty vehicles are more prone to rollover compared with passenger cars for their higher gravity center, it is important to prevent the commercial vehicles from rolling over during cornering or high-speed evasive directional maneuvers. In order to improve the roll stability of a 3-axle straight truck, a rollover prevention system based on independent brake force control is proposed. The differential braking is calculated by solving a robust stabilization problem in consideration of the variation of vehicle speed and tire cornering stiffness. The model errors are calculated through simulations. When vehicle is in sharp cornering and vehicle speed is high, applying sudden brake (normal brake without distribution) is dangerous for vehicle stability and make tires work in a combined cornering and braking condition. We simulate such a maneuver and use the simulation results to calculate the time-variant tire cornering stiffness and vehicle speed. The criterion of rollover risk is also analyzed, and a logic combination of lateral acceleration and roll motion is used to judge rollover risk. Finally the proposed rollover prevention system is tested on a truck simulation model constructed by TruckSim. Simulation results of J-turn maneuver and lane change maneuver show that the proposed system can prevent rollover effectively.
Keywords: Truck, Rollover Prevention, Vehicle dynamics, Roll Stability, Robust Control