Vehicle driveability evolves more and more as a key decisive factor for marketability and competitiveness of passenger cars, since the final decision of customers to buy a car is usually taken after a more or less intensive test drive. Car manufacturers currently evaluate vehicle driveability with subjective assessments and by having their experienced test drivers fill out form sheets. These assessments are time and cost intensive, limited in repeatability and not objective. The real customer requirements cannot be recognized in detail with this method.
This paper describes a completely new approach for an objective and real time evaluation of relevant driveability criteria, for use in a vehicle and on a high dynamic test bed. The vehicle application enables an objective comparison between vehicles and an application as a development tool in many development and calibration phases, where ever fast and objective driveability results are required. The application of the driveability evaluation tool AVL - DRIVE™ on the high dynamic test bed facilities, enables for the first time a prediction of vehicle driveability without using the vehicle.
Engine and engine management system optimizations on a high dynamic test bed can be done very effectively by simultaneously considering performance, fuel consumption, emissions and driveability. This approach is a very important step towards a “road to rig” development philosophy and enables the reduction of test vehicle numbers by up to 50 %. The duration of common driveability tests can be dramatically reduced by a factor of 5, from 1 - 5 weeks to 1 - 5 days. Calibration time can be reduced by 40 % while a customer oriented calibration is possible. Driveability quality can be increased, which leads to a higher customer acceptance.