This paper introduces the kinematical and dynamical model as well as a quasi-static trajectory control of a self-balancing two-wheeled vehicle. The mobile robot is about 60cm tall, autonomous, unstable and driven by two wheels. Hence, it can be used for transport purposes. Due to the nonholonomic constraints only few modeling techniques are feasible. In this case, the modeling is based on the Projection Equation, followed by the derivation of various control strategies.

In order to allow a desired velocity and to stabilize the inclination angle of the robot a partial feedback linearization in combination with a LQR controller is applied. The quasi-static trajectory controller, which is based on the kinematical model, uses a flatness based approach in order to remain on the desired path. Continuous curvature paths, composed by clothoids, enable good performance results in simulation and experiment. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)