Torque Vectoring AWD Driveline: Design, Simulation, Capabilities and Control

Abstract

<div class="htmlview paragraph">This paper reports interim developments and findings prior to completion of an extensive R&D program that encompasses novel driveline hardware including an electrical modulation element to bias front and rear propeller shaft torque, and the control of this type of active driveline in respect of traction and vehicle dynamics. The AWD hardware has been fitted to a BMW X5 vehicle, with a winter test planned for January 2004 prior to wider demonstration.</div> <div class="htmlview paragraph">Specifically, the following are discussed:</div> <div class="htmlview paragraph"> <ul class="list disc"> <li class="list-item"><div class="htmlview paragraph">The AWD market.</div></li> <li class="list-item"><div class="htmlview paragraph">Functional description of the novel torque biasing hardware including EASY5™ simulation results of the device and its influence upon the relative slip of the front and rear axles.</div></li> <li class="list-item"><div class="htmlview paragraph">Hardware elements of the variable torque bias coupling.</div></li> <li class="list-item"><div class="htmlview paragraph">Electrical system.</div></li> <li class="list-item"><div class="htmlview paragraph">Novel features such as a dual-drive lubrication system, a practical design for driveline torque sensing, and the hybrid vehicle potential of the device with additional connectivity for the e-machine.</div></li> <li class="list-item"><div class="htmlview paragraph">Simulation environment for vehicle dynamics applied with IPG™ CarMaker™ and Simulink™ RTW™. Software Implementation using ASCET-SD™.</div></li> <li class="list-item"><div class="htmlview paragraph">Traction control strategy and simulation results.</div></li> <li class="list-item"><div class="htmlview paragraph">Yaw velocity control and simulation results.</div></li> <li class="list-item"><div class="htmlview paragraph">Calibration of vehicle handling characteristics.</div></li> <li class="list-item"><div class="htmlview paragraph">Review of benchmarking data for a BMW X5.</div></li> <li class="list-item"><div class="htmlview paragraph">Novel actuation and driveline devices: MRF actuator and modulation devices for driveline.</div></li> <li class="list-item"><div class="htmlview paragraph">Conclusions to date.</div></li> </ul> </div> <div class="htmlview paragraph">On completion of this project further publications will provide validated results and further analysis. The reader will appreciate that extensive description of all project facets cannot be accommodated within the confines of a single paper.</div>