Stabilization of a Riderless Bicycle [Applications of Control]

The bicycle provides transportation for leisure, recreation, and travel between home and work, throughout the world, in big cities as well as in small villages, supporting human mobility for more than a century. Modeling, analysis, and control of bicycle dynamics has been an attractive area of research in the last century as well as in recent years. Bicycle dynamics has attracted the attention of the automatic control research community because of its peculiar features, such as, for example, the fact that it depends strongly on the bicycle speed and that, under certain conditions, it exhibits both open right-half plane poles and zeros, making the design of feedback controllers for either balancing the bicycle in the upright position or moving it along a predefined path a challenging problem. In this article, the LPV nature of the bicycle dynamics is exploited to design a control system that automatically balances a riderless bicycle in the upright position. More precisely, the problem is formulated as the design of an LPV state-feedback controller that guarantees stability of this two-wheeled vehicle when the speed varies within a given range and its derivative is bounded.