Electric Scooter Dynamics – From a Vehicle Safety Perspective

Preliminary results of a comprehensive study on the dynamic behaviour of e-scooters are presented, referring to straight-line stability and emergency braking. Both scenarios are of particular interest from a vehicle safety perspective. Simulation studies and on-road tests are performed. Model parameters are obtained from laboratory measurements as well as from on-road measurement data. Stability analyses based on the benchmark bicycle model reveal a self-stable behaviour for a range of usual forward speeds. Extensions of the model w.r.t. rider body lean and a linear tyre model are discussed. Braking strategies for effective emergency braking manoeuvres are shown to essentially involve the body position of the rider. Due to limited braking forces generated by the front regenerative braking system, riders should be encouraged to shift their body position further to the rear and rely on rear brake as well, which is shown to be an effective strategy to reduce stopping distances.