Each OEM has a distinguishing drivability character that defines its image in the market to achieve brand differentiation. Drivability is one of the important factors along with fuel economy that determines the success of a vehicle vis-à-vis its competitors. It can be said that the need for good drivability among customers is increasing day by day similar to the need for high fuel economy.
Drivability is the response that a vehicle delivers to the inputs of the driver which are mainly accelerator, brake, clutch, gear and steering. The dynamic response of the vehicle is mainly in terms of velocity and acceleration. The way the response is delivered will characterize the drivability of a vehicle.
The drivability event discussed in this paper is throttle tip-in response which is one of the critical evaluation factors for defining the character of a Sports Utility Vehicle. Objective methodology tool AVL Drive is used for the study since it can evaluate on an extensive basis as well as provide micro level analysis.
Longitudinal acceleration is measured using an accelerometer and other parameters like engine speed, velocity, accelerator pedal position are logged from CAN bus. Tip-in events at different gears and engine speeds are performed and data is captured real time using Drive Main Unit. This data is further processed using Drive software and a rating is obtained.
Tip-in response character is optimized using a closed loop optimization strategy and response delay time reduced and over all response of vehicle is improved from base level after optimization.