Driving force distribution based on tyre energy for independent wheel-drive vehicle on rough ground

The driving force of a wheel is an important factor to determine the travelling performance of vehicles on rough grounds. An excessive driving force induces a large slip, whereas insufficient driving force prevents vehicles from overcoming obstacles. Hence, an optimum driving force distribution is necessary to improve the travelling performance of off-road vehicles on rough grounds. In this study, the driving force distribution method of four independent wheel-drive vehicles based on the energy-loss ratios of the wheels is proposed. The squared sum of the energy-loss ratios is minimized in the proposed method. To validate the proposed method, travelling tests were conducted using a model vehicle on a rough and rigid ground and a soft ground. Moreover, simulation tests were performed on a rough and rigid ground. The results obtained using the proposed method were compared with those of the distributions based on the tyre workload, even force, and wheel-velocity control. The experimental and simulation results confirm that the proposed method is the most efficient for vehicles moving on a rigid ground. The movement of the vehicle on the soft ground was the most stable when the proposed method was employed.