Zhuo, G., Zhang, S., and Xiong, K., "Design and Research of Micro EV Driven by In-Wheel Motors on Rear Axle," SAE Technical Paper 2016-01-1950, 2016, doi:10.4271/2016-01-1950.
As is known to all, the structure of the chassis has been greatly simplified as the application of in-wheel motor in electric vehicle (EV) and distributed control is allowed. The micro EV can alleviate traffic jams, reduce the demand for motor and battery capacity due to its small size and light weight and accordingly solve the problem that in-wheel motor is limited by inner space of the wheel hub. As a result, this type of micro EV is easier to be recognized by the market.In the micro EV above, two seats are side by side and the battery is placed in the middle of the chassis. Besides, in-wheel motors are mounted on the rear axle and only front axle retains traditional hydraulic braking system. Based on this driving/braking system, distribution of braking torque, system reliability and braking intensity is analyzed in this paper. In order to coordinate with traditional hydraulic ABS control to ensure the braking stability of the vehicle, model following control (MFC) is adopted to fully utilize the fast and accurate torque response of motor for slip prevention and control effect influenced by characteristics of motor is analyzed. In conclusion, only simple and minor changes have been made to the braking system of traditional vehicle which makes the micro EV cost less and easier to popularize.