Riding a bicycle without hands, while being pleasant and sometimes challenging, exposes the self stabilizing properties of the bicycle. While human balancing techniques are widely understood, balancing on a bicycle is predominantly done by turning the handle bars and not many det
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Riding a bicycle without hands, while being pleasant and sometimes challenging, exposes the self stabilizing properties of the bicycle. While human balancing techniques are widely understood, balancing on a bicycle is predominantly done by turning the handle bars and not many details about body motion control strategies are understood yet. Therefore, creating a rider model that controls the bicycle solely by lateral body motion enables these strategies to be amplified and better appreciated. Only controlling the bicycle by lateral body motion also gives more insight into the relation between roll and steering dynamics as the steering control is non-existent. Further inspiration for the model is obtained by analyzing motion capture data of a rider on a bicycle. This thesis describes the process of creating such a hands-free rider models and the development of simulation tasks to examine this control behavior. These tasks involve performing a double lane switch maneuver, a 90◦ turn and riding through perturbations. The model is created using the BRiM software package, and simulations are performed by optimal control program Opty, which allows for the symbolic equations of the Whipple bicycle model to be used for multi-body-dynamics calculations. After analyzing the control strategies employed by the rider, new insights are obtained on the lateral mechanics of bicycle control, paired with improved joint mechanics that have not been used before in bicycle-rider models. Such new joint mechanism modelling the seat connection between bicycle and rider, that couples lateral translations to body lean proves to be moreeffective than only rider body lean. Also, in terms of optimal control, using a multi-link pendulum model for the rider does not increase the control performance of the rider compared to a single pendulum rider lean model. Furthermore, novel evidence is presented that disproves the assumed need for counter-steering when attempting to make a turn. The rider can make a steady turning motion without having to initially steer in the opposite direction of the turn. Moreover, the effects of placing a spring between the front- and rear frame of the bicycle, both in stabilizing the bicycle as making the bicycle more responsive are investigated. From this it is found that adding a spring will increase the self-aligning properties of the front wheel but that it hampers maneuverability. Finally, the results of this thesis are put in perspective, and recommendations and improvements for future work are shared.