Design and simulation of control systems for electric-assist bikes

Control design plays a key role in electric-assist bikes. This paper has established dynamic models of electrically assisted biking systems, and then, designed proportion-assisted power controllers (PAPC) in accordance with Taiwan government rules. In the PAPC controllers, current bike speed and pedal torque are used as inputs to determine the assisted torque generated from a motor. On the other hand, a fuzzy logic controller (FLC) has been also designed, using the current bike speed and pedal frequency as inputs to determine the assisted torque. In order to compare these two controllers, simulations of riding bikes on a flat ground and different slopes have been performed. Simulation results show that the FLC outperforms PAPC in a more stable bike speed.