Abstract
In this study, a double-wheel self balanced unicycle is proposed. Because of the shortage of energy resource and parking space in city, the idea of this light-weight electrical aid personal unicycle can hopefully be used in future transportation system. The unicycle has the features of small longitudinal length, with two coaxial wheels and pedal by human with electric control system to balance the unicycle. It is known that when the rider rides the unicycle, the paddle force disturbs the balance of the vehicle. This unbalance force comes from the gravity center is not at the point of the ground contact points of the vehicle. To balance the unbalance force, two servo-motors to drive the two wheels are used. The unbalance condition is detected by sensors. A transmission mechanism to combine human power and electric power is designed. Planetary gear set is considerable to be the basic concept of transmission mechanism design. The sequence of study processes would be helpful to design the layout of the transmission about chassis, bike frame, and wheels. The mechanism design could link up the mechanical system with the motors and electro-control system.