Improving vehicle performance in terms of both torque and power is a strong customer need in both conventional and electric vehicles. In this work, different two speed automatic transmission (AT) concepts are developed to improve the energy efficiency and performance of battery electric two wheelers. Developed transmission systems are simple, compact and cost effective and results in relatively high energy efficiency of an electric motor. The unique shift control strategy ensures motor to operate at higher efficiency zones to minimize the overall energy consumption. Virtual simulations of electric vehicle were carried out for different driving conditions and optimal transmission ratios were determined.
Mechanical behaviors such as gear shift characteristics, linear and angular velocities, inertial forces of each components are analyzed by using Multi body dynamics simulation. Forces predicted here are further used for durability studies of these components. The developed system combines superior shifting accuracy, high transmission efficiency with increased grade ability and results in substantial improvement in acceleration while retaining top vehicle speed without much compromise.
