Fuzzy sliding mode control of a riderless bicycle with a gyroscopic balancer

In this paper, we developed a riderless bicycle with a gyroscopic balancer controlled by fuzzy sliding mode control (FSMC). The riderless bicycle with the gyroscopic balancer and FSMC controller has the advantages of fast system response and relatively high robustness to disturbances. Even if hit by a bottle, filled with two liters of water, suspended 50 cm away from a pivot like a pendulum, and swung 90 degrees from its equilibrium position, the bicycle is still highly stabilized. The gyroscopic balancer is the balancer with the least mass ratio of balancer to bicycle among various bicycle balancers, and it can effectively produce a moment to prevent the bicycle from falling down. Moreover, the bicycle with the gyroscopic balancer controlled by FSMC can outperform the one with PID under highly uncertain environment. The FSMC intuitively comprehended by human operators is suitable for bicycle manipulation. It can significantly reduce the design complexity of a controller for the riderless bicycle. The design idea of FSMC is creating a sliding surface served as a balancing index which incorporates three factors, the lean angle of the bicycle, the rate of lean angle of the bicycle, and the rotation angle of the gyroscopic balancer. The bicycle dynamics model with the gyroscopic balancer is proposed to simulate and validate the design concept on the balancing performance of the bicycle with FSMC. Finally, experiments are designed to demonstrate that the riderless bicycle system remains upright and stationary under impact disturbances even when the bicycle doesn´t move forward. Furthermore, since the results of experiments are consistent with the ones of the simulation, it validates the derived bicycle dynamics model with the gyroscopic balancer and proves its robustness.