An experimental study for drivability improvements in vehicle acceleration mode

Abstract

Modern vehicles require a high degree of refinement, including good drivability. Vehicle drivability, which becomes a key decisive factor for marketability, is affected by many parameters such as engine control and the dynamic characteristics in the drivelines. Therefore, engine and drivetrain characteristics should be analysed to achieve a well-balanced vehicle response simultaneously. This paper describes experimental procedures that have been developed to measure engine torque and investigate shuffle characteristics. A simplified powertrain model is presented for vehicle dynamic response analysis. Submodels within the model are the engine and drivetrain. Using this model, the friction and inertial moment for each submodel were measured, and effects of parameters were analysed. To analyse vehicle dynamics behaviour, frictional torques and the rotational inertia moment of the engine and the drivetrain were measured. Shuffle characteristics at the tip-in condition were investigated in an experimental vehicle at the second and third gear stages. It was found that shuffle characteristics are caused by sudden changes in engine torque and have a different vibration frequency with gear stage variation. The rotational inertia moment of the engine, including flywheel rotation, is a key factor influencing the shuffle characteristics.