Vehicle Drift Investigation during Straight Line Accelerating and Braking

A vehicle drifts due to several reasons from its intended straight path even in the case of no steering input. The multibody dynamic analysis of vehicle drift during accelerating and braking are performed. This paper focuses on modeling and evaluating effects of suspension parameters, differential friction, engine mounting and C.G. location of the vehicle under multibody dynamic simulation environment.

Asymmetry of geometry and compliance between left and right side is considered cause of drift. The sensitivities of the suspension parameters are presented for each driving condition. In case of acceleration, the interaction of differential friction and driveshaft stiffness and their influence on drift are also studied. For braking condition, suspension parameters such as initial toe variation of rear coupled torsion beam axle type suspension and kingpin inclination deviation of front suspension are studied including the braking force difference.

The significant factors of drift are ordered and compared for straight line accelerating, driving and braking condition. Using a co-simulation model, it is shown that significant parameters for accelerating condition are driveshaft angle and its stiffness difference between left and right side. It is shown that the location of center of gravity altered by passenger seating position has a great influence on drifting under braking condition.