The University of Tokyo and Mitsubishi Motors jointly developed a system that controls the distribution of driving power between the front and rear wheels automatically for smaller power consumption and longer travel distance of a vehicle. The system automatically calculates the driving power and the optimal power distribution using speed, currency, and voltage while a vehicle is running. It calculates the distribution four times in every 1.5 seconds. The research team used a PX-MiEV, a Mitsubishi Motors’ sports utility vehicle, that has motors for each of the front and rear wheels for the development. When compared with a conventional electric vehicle with a 50:50 power distribution of a motor, the newly developed system realized a decrease of about 1 kW in power consumption and an increase of about 20% travel distance for constant speed running of 50 km/h.
The University of Tokyo has been developing a system to increase the travel distance by changing the distribution of motor’s driving power, but the problem with the inability to maintain the optimal distribution because of the heat generated while a vehicle is running remains unsolved. The research team will work on increasing the efficiency in case of frequent acceleration and decreasing the search time to put the technology into practical use. Mitsubishi Motors plans to launch a plug-in-hybrid (PHV) based on the vehicle used in the experiment toward 2013.
Test drive of Mitsubishi Motors’ MiEV on the road