In-wheel and on-board motors in BEV: lateral and vertical performance comparison

Following the electrification trends in the automotive sector, many powertrain architectures are being studied, and among them a very interesting possibility – not yet fully developed – regards the use of in-wheel motors. This kind of electric machine positioned inside the wheel rims grants the vehicles great design freedom and opens numerous possibilities in terms of vehicle control, however some issues regarding handling and comfort are raised with the increase of the unsprung mass. This paper proposes a comprehensive study, combining the electric modelling of the motors, inverter, and battery using Simulink and its co-simulation with multibody simulation in Adams/CAR, in such a way that a full electromechanical coupling is achieved, and a full range of dynamic phenomena can be inquired both for an in-wheel and an onboard EV setup. The paper focuses on lateral and vertical performance, since they represent the main controversies in the adoption of in-wheel motors, and promising results are obtained.