Design and control of an electrically assisted kick scooter

Traffic congestion, energy efficiency and environmental issues are fueling the interest in Light Electric Vehicles (LEV's). Electric Human-Powered Hybrid vehicles show a great potential: they are cost effective, safe, easy to use and have a small footprint. In this paper, we discuss an electrically assisted kick scooter. Electric scooters are common on the market but, being throttle-controlled, they sit in a legislative gray area between human powered vehicles and electric vehicles. The proposed design solves this issue by designing a genuine electrically assisted scooter. The proposed design does not have any human machine interface but controls the electric assistance in a transparent way. The user only needs to kick the scooter as she would do with a normal scooter and the control system smoothly delivers the assistance. The proposed solution is based on a kick detection algorithm and a closed-loop control of the vehicle velocity. The details of the control system are discussed in the paper and an extensive experimental validation shows that the electric assistance cuts in half the effort necessary to operate the vehicle with a battery consumption of 4 Wh/km (half that of an electrically assisted bicycle).