Abstract
Dicycle is a two-wheeled unicycle with two wheels axially aligned. The effect of interaction between a self-balanced dicycle and a rider has been investigated experimentally by measurements of state of motion. Dicycle can be seen as an inverted pendulum, which is an unstable system. The controller of the self-balanced dicycle and the rider control the balance of dicycle simultaneously. The controller controls the motor to afford torque, which keeps balance of the rider-dicycle system by moving dicycle forward and backward. At the same time, the state of stabilization changes when rider changes its posture or applies force on dicycle. The interaction between rider and controller can cause resonance of human-machine combined system. A method to investigate the resonance frequency under human operation is present. The resonance frequency is estimated from a mathematical modal combining rider and inverted pendulum. The dicycle is composed of seat, handlebars, and pedals installing on a Segway. The position of seat, handlebars, and pedals can be adjusted to suit different center of gravities of riders in order to keep controllability of Segway. Subjects rode under different conditions, which is riding forward and backward on level ground, crossing speed bump, and stopping abruptly after accelerating. The state of motion is measured through combined gyro sensor and accelerometer. A discussion of the design property of the self-balancing controller is made according to the reaction of riders.