Kalman Observer based Optimal Torque Distribution Control for the Range Extension of Electric Vehicles with In-Wheel motors

Even though Electric Vehicles (EV) are the accepted alternative for the conventional IC engine driven vehicles, the major limitations of the transportation revolution based on Electric Vehicles are the modest range provided by the electric vehicles. This boil down the energy efficiency and fuel efficiency of the comparatively costlier EVs. Many methods for driving range extension like using range extenders requires reconfiguration of the vehicle power train and are not energy efficient. The paper proposes range extension by improving the energy efficiency of the vehicle with an optimal driving force and torque distribution control law. By using optimal distribution law, the energy utilized for achieving any desired speed can be minimized; thereby saving the fuel which can be used to go an extra mile. The driving force distribution law is formulated with the knowledge of the vehicle and wheel dynamics and the optimal law, realizing minimum energy consumption is obtained by applying particle swarm optimization. The optimal torque distribution is realized with the help of Kalman filter based observer for force estimation. The design of optimal law and optimal torque distribution with minimal energy consumption is verified with the help of a simulation study on a test vehicle. The method proposed countenance on-line estimation of the optimal distribution ratio, never discussed before, leading to energy efficient operation of the vehicle.