Among the great number of possible drive train configurations, the application of visco coupling elements combines an improved distribution of tractive forces with a driver independent performance. To investigate the straight ahead accelerating and kinematic cornering of a vehicle with such visco elements a simulation with a four wheel vehicle model is employed. The drive train thereby comprises engine characteristics, central distribution gear and rear differential, each with a different visco coupling. For comparison, a completely locked drive train is considered as well. The longitudinal transient tyre characteristics approximation is valid for arbitrary slip values on high and low friction surfaces. The results compare the performance of 8 different drive train configurations for the following cases: straight ahead acceleration on mu- split surface; kinematic cornering on a high friction surface; and the unilateral crossing of a low friction patch extending the wheel base 1.5 Times with a medium acceleration. A configuration of a central distribution gear with a parallel visco coupling and a soft visco coupling at the rear differential can be found to be a good compromise for all the driving duties.
Abstract