This work is focused on the modeling and experimental validation of a steer-by-wire system for bicycles. The purpose for this system is to modify and enhance the lateral stability of a bicycle at low forward speeds. Case studies show additional capabilities of a steer-by-wire system on bicycles to influence its dynamic behavior, by providing a dynamic response comparable to a bicycle with a virtually different geometry or even the ability to stabilize an inherently unstable bicycle. A steer-by-wire bicycle prototype was designed and build by replacement of the mechanical connection between handlebar- and steering-assembly by electronic actuators and a custom digital controller. The steer-by-wire bicycle prototype equipped with sensors, measuring the forward speed and roll-rate was subsequently used to experimentally evaluate the proposed control algorithms. Preliminary rider tests showed a perceived near-to-identical behaviour of the steer-by-wire system to a mechanical connection. Adding lateral stability enhancement at low speed by active steer-torque control was perceived as beneficial by the rider. (Author/publisher)
Abstract