Mechatronics-Based Analysis of a 4x4 Vehicle Lateral Dynamics With Passive and Active Drivelines

This paper presents a mechatronic modeling analysis of a 4×4 hybrid-electric vehicle (HEV) which uses an active driveline system connected to the hybrid powertrain. This active driveline uses a power-splitting device, named a Hybrid-Electric Power-Transmitting Unit (HE-PTU) to control the power split between the front and rear axles. The mathematical model of the active driveline along with two passive drivelines demonstrates the coupling of driveline-steering-system influenced lateral dynamics of the vehicle. Thus, a more flexible, active driveline is able to effectively decouple the driveline and steering systems by producing a compensating torque that influences the tire lateral forces and thus vehicle lateral dynamics. Because of the multiple domains involved in modeling the HE-PTU, a mechatronics-based modeling solution is required to demonstrate the advantage of the active driveline. The mechatronics-based simulation results show how use of the active driveline with a hybrid-electric power transmitting unit can improve the vehicle’s turnability and stability characteristics.