Swing up control of inverted pendulum

A bang-bang-type state feedback control algorithm which can swing up a pendulum from a pendant position to an upright position is proposed. In the control system a conventional LQ control method is also employed around the upright position to maintain the pendulum in the upright position after the pendulum has been swung up to this position by the bang-bang control. The control system was constructed and the validity of the control method was examined experimentally. Since the pendulum is attached by a hinge to a rotating arm fixed to a direct drive motorshaft, it contains fewer uncertainties introduced by transmission mechanisms, e.g., a belt and gears in a linear-type inverted pendulum. The advantages of the designed pendulum are that it is small and saves experimental space, and that the robustness of control algorithms can be easily tested with it since known parasitics can be added as uncertainties in the control loops, e.g., a flexible arm can be used instead of a rigid arm