Self-excited full-vehicle oscillations in dynamic packaging examination

Abstract

Dynamic clearance studies in test drives for vehicle approval include starting-off manoeuvres for ascertaining the maximum space required by the engine/gearbox unit in the longitudinal direction of the engine. Under certain circumstances, sharp moving-off procedures can result in what is referred to as the power hop phenomenon. This is an oscillation of the chassis, suspension and powertrain boosted by the tyres, which not only increases the amount of space required but also reduces driving comfort. In this paper, the Institute of Automotive and Power- train Engineering (IFAS) of the Helmut Schmidt University (Federal Armed Forces University) Hamburg and Volkswagen AG not only discuss the measuring technology used and offer an interpretation of the effect, but also provide an outlook as to reproducibility and treatment of the phenomenon.