Study on the postural and driving control of a coaxial bicycle.

The postural and driving control of a coaxial bicycle which has a twin wheel and an upper structure on its driving axis has been studied. The bicycle is modeled as an inverted pendulum pivoted on the wheel axis. In this study, a controlling moment, that is, a restoring torque on thee inverted pendulum is applied by controlling the rotation of the wheels. A control system of the model has been designed according to the proportional feedback control method, in which feedback gains can be determined by Routh-Hurwitz's stability criteria. Experiments were carried out using these feedback gains and we have succeeded for postural control together with driving control of the coaxial bicycle. It is confirmed experimentally that the feedback gains derived from the analysis are available in the postural control and the vehicle can be driven in an arbitrary direction by altering two proportional gains corresponding to its inclination.