A Bicycle Electric Assist Unit

Abstract

The BEAU is an electric-assist bicycle system that is completely self-contained within the rear wheel. The purpose of approaching a electric-assist bicycle in this manner is two-fold: simplifying the device and opening the method of implementation to more creative uses. The project requires a large amount of knowledge from many fields. Based on the limits of research, the project will show the aspects of the BEAU's design and how they meet the overall design goals of the project. The BEAU is made up of several parts, none of which include a bicycle. The design of the BEAU takes the bicycle and rider into account only for aesthetic and control reasons. Inside the BEAU reside a custom motor, closed loop controller with power electronic drive elements for the motor, battery pack with custom battery management circuitry, and torque and rotary position encoders. The simplification of both the device required to electrify a bicycle and the user input required to control such a device is intended to make the BEAU a very attractive electric bicycle conversion alternative that can be used not only for consumer uses, but also in situations of mass utilization, such as a bike sharing program. This research was completed entirely within the Smart Cities group by the author. The original concept of the BEAU was arrived at during a meeting with the late William J. Mitchell as the "GreenWheel" and the project was begun as a team effort with Michael T. Lin, also of Smart Cities. The BEAU manifestation is entirely of the authors design with the purpose of investigating some of the more theoretical aspects of the GreenWheel concept.