Stability Analysis of Bicycles and Motorcycles

The early motivation for this work came from reports of oscillatory vehicular instabilities from motorcycle racers, as well as reports from a respected motorcycle manufacturer. The racers were having difficulty setting up their machines so that they would not be troubled by either wobble or weave. Fixing one appeared to undermine the other. Manufacturing reports indicated that these problems have a significant non-steady- state speed dimension; under some circumstances their racing machines would oscillate under acceleration. These difficulties have been addressed in earlier work under the somewhat restrictive constant-speed assumption, with a solution coming from linear time-invariant models. The non-steady-speed case has not been addressed, but the advantages of a time-invariant analysis and design framework for studying these problems should not be surrendered lightly. This book firstly presents a time-invariant framework within which an accelerating/braking vehicle can be studied. Key ideas in the context of a bicycle are developed, which are then implemented on a modern sports motorcycle model. Close agreement with experimental results is found.