Lee, H., Tesar, D., and Ashok, P., "Expanded Human Choice based on Duty/Demand Cycles for In-Wheel Motors in Electric Vehicles," SAE Int. J. Passeng. Cars - Mech. Syst. 10(1):2017, doi:10.4271/2016-01-9114.
In order to design the in-wheel motor (IWM) for Electric Vehicles (EV), it is necessary to analyze the desired (expected) duty cycle at a higher performance level in order that the IWM becomes commercially relevant. The duty cycle may be representative of different segments of the customer base. Or, the individual customer may wish to have a set of IWMs that uniquely meet his/her measured “demand” cycle for a balance of drivability and efficiency. Questions then arise: How to measure the demand cycle of an individual? What 2 or 3 standard duty cycles should be offered as customer choices for their vehicle? Should the IWM represent multiple speed domains to enhance efficiency and drivability? Can the vehicle be updated rapidly 2 to 3 years after purchase? Etc. In this paper, we lay the groundwork to answer these types of customer questions for an EV with four independent IWMs. In addition, we propose the customer-oriented duty cycle analysis in order to obtain not only how to maximize efficiency (efficiency-priority driver) but also how to maximize drivability (aggressive driver), based on the existing driving cycles: Urban Dynamometer Driving Schedule (UDDS) and Aggressive Driver (US06). Given the individual demand cycle, the EV can be tailored to meet the particular customer, which leads to expanded human choice which can be characterized in terms of two basic operating regimes: efficiency and drivability.