Details about our projects related to bicycle dynamics, handling and control.<\/p>\n
The bicycle with a human rider comprises a human-vehicle system whose dynamic behavior is poorly understood. The reasons for this are varied, but include complex kinematic vehicle constraints, tire-roadway interactions, and difficulty in realistically modeling relevant human behavior. In contrast with an automobile or aircraft, the pilot of a bicycle comprises 80%-90% of the overall system mass and thus the motion of the human rider is not negligible. For these reasons, the voluminous research addressing modeling the bicycle over the last century has resulted in few useful design guidelines for the construction of bicycles with desired handling qualities. We believe the key to developing these guidelines lies in understanding the control strategies of the human rider.<\/p>\n
The goal of our research is to development of experimentally validated models of both the bicycle and rider with the latter element building upon the established discipline of manual control theory. The bicycle and rider models will be used to establish design methodologies for bicycles that exhibit desirable handling qualities for safe operation. The four elements of our research are the (1) development of dynamic models of the bicycle with rider, (2) development of control-theoretic models of the human bicycle rider, (3) experimental validation of both the bicycle and human operator models, and (4) development of a methodology for prediction of\u00a0 bicycle handling qualities.<\/p>\n
<\/a><\/p>\n The bicycle can help reduce energy use, improve health, and decrease the environmental impact of personal transportation. For example, studies (Bassett et al., 2008<\/a>) show inverse correlations between active transportation (including bicycling and walking) and obesity rates in European nations, the United States, Canada, and Australia. In the Netherlands and Denmark, respectively, 18% and 27% of local trips are by bicycle, whereas in the\u00a0 United States bicycles are used for less than 1% (Bassett et al., 2008<\/a>). Bicycle usage might increase if designers had more insight into their design choices for different populations (e.g. elderly, children, disabled, average adult) and different tasks (e.g. cargo transportation, commuting, recreation). This added insight requires a much greater understanding of rider-bicycle dynamics, interaction, and control.<\/p>\n The bicycle also provides a framework for introducing engineering students to a variety of complex problems in system dynamics and control. These include multi-body dynamics, nonlinear and linear system descriptions, holonomic and nonholonomic constraints, biomechanics, human control, and system simulation and instrumentation. The bicycle is also a vehicle with which the average student is intimately familiar and makes it an ideal educational tool at many levels. For example,\u00a0Fajans (2000)<\/a>discusses the concept of steering in bicycles and motorcycles in a journal devoted to the instructional and cultural aspects of physical science. Our research will provide the technical information for educators to introduce the bicycle as a useful and instructive classroom example.<\/p>\nBroader impacts<\/h3>\n