Automatic bicycle balance assistance reduces probability of falling at low speeds when subjected to handlebar perturbations version 5

Abstract

Uncontrolled bicycles are generally unstable at low speeds. We add an automatically controlled steering motor to a consumer electric bicycle that stabilizes the riderless bicycle down to just below 4 km h⁻¹ to assist a rider in balancing the vehicle. We hypothesize that a such a stabilized bicycle will reduce the probability of falling. To test the system's possible assistance during falls, we applied varying magnitude external handlebar perturbations to twenty-six participants who rode on a treadmill with the balance assist system both activated and deactivated. We show that the probability of recovering from a handlebar perturbation significantly increases when the balance assist is activated at a travel speed of 6 km h⁻¹. This positive effect is most prominent at and around the individual riders’ perturbation resistance threshold. We conclude that use of a balance assist system in real world bicycling can reduce the number of falls that occur near riders’ control authority limits.