Fast and Accurate Road Interference Compensation for Objective Drivetrain Evaluation

In cooperation with the Institute of Automotive Engineering of the Technische Universität Braunschweig and AVL List GmbH, a system to compensate the influence of the road surface on the objective driveability assessment is developed. Based on an existing simple function in AVL-DRIVE^TM (The Objective Tool for Driveability Assessment and Development) a system with two vertical-longitudinal axis wheel sensors is created. By this, road surface interferences on the left and right side as well as on the front and rear axle of the vehicle are considered, and the influence on the longitudinal acceleration signal, which is the main input for driveability evaluation, can be effectively compensated. In this work the influence of different road interferences on the longitudinal acceleration is measured and investigated in different driveability maneuvers like accelerator pedal tip-in or gearshifts. The principle of the road interference compensation based on multiple wheel acceleration input signals is shown, and a performance optimized algorithm is developed. While four sensors would be required to acquire the inputs of all four wheels a way to effectively compensate all wheels with only two sensors is integrated in a real time capable environment. The aim of this cooperation was to take a further step towards public road driveability assessment. Usually, this is done on test tracks with consistently good road surface conditions and exactly reproduced driving maneuvers. In contrast, during public road driving, all kinds of road surface conditions are found, significantly complicating the objective driveability assessment. With the road interference compensation, the influence of the road surface is decisively reduced.