Torque control strategy for off-road vehicle mobility.

Multi-wheeled off-road vehicles behavior depend not only on the total provided power by the engine but also on the power distribution among the drive axles/wheels. In turn, this distribution is primarily regulated by the drivetrain layout and the torque distribution devices. At the output of the drivetrain system, the torque is constrained by the interaction between the wheels and the soft terrain. For off-road automotive applications, the construction of drivetrain system has usually been largely dominated by the mobility requirements. With the growing demand to have a multi-purpose on/off road vehicle with improved maneuverability over soft soil particularly at higher speed, the challenges confronting car designers have become more sophisticated. A number of simulation studies, during longitudinal and cornering maneuvers, are conducted to investigate the contribution of typical significant parameters. In addition, the influences of different drivetrain arrangements are presented. The obtained results defined that both traction and cornering response of multi-wheeled off-road vehicles are highly affected by the driving torque distributed between axles/wheels. In this thesis, the main challenge is to develop an effective torque distribution control strategy to improve both directional dynamics and safety of the vehicle. The developed torque vectoring control strategy can be widely applied to vehicles of two or more axles. In this research work, the application to multi-wheeled combat vehicles is extensively investigated. An advanced fuzzy slip control and a yaw moment control systems designed, and both performance and effectiveness of the developed controllers evaluated using different standard test maneuvers. Finally, the integrated control systems investigated to verify the proposed control strategy effectiveness on the vehicle direction stability and mobility based on some predefined standard test maneuvers