Development of an evaluation method for quantitative driveability in heavy-duty vehicles

Subjective evaluations by experienced test drivers are primarily used to assess the driveability of vehicles in automotive companies. However, these evaluations are limited in terms of repeatability, incur costs, and require much time. Therefore, this study introduces a method of quantitatively evaluating the driveability of heavy-duty vehicles to circumvent these limitations. A vehicle experiment is conducted to measure data from an electronic control unit and an accelerometer to assess the driveability of heavy-duty vehicles. The evaluation indices for driveability are selected from previous studies on the objective and subjective methods of evaluating driveability according to various driving conditions. The indices include engine start, idle, acceleration, deceleration, constant speed, and start-up driving conditions. This research presents a quantitative evaluation method using the calculated values of each index and the correlated weighting factors of indices obtained from the regression analysis of the subjective evaluations. The driveability of heavy-duty vehicles is quantitatively evaluated under various driving conditions based on the proposed method. Results of the quantitative evaluation are similar to those of the subjective evaluations, and the proposed method is determined applicable in evaluating the driveability of heavy-duty vehicles.