車輪型倒立振子ロボットの速度追従制御

―非最小位相系に対するバックステッピング法の適用―

抄録

This paper proposes a velocity tracking control strategy based on the backstepping method for a Wheeled Inverted Pendulum Robot (WIPR). However, it is difficult to apply the high-gain feedback control to WIPR because of an unstable zero. Proposed strategy comes up with following solutions. First, a linearized model is created using the coordinate transformation to separate the unstable zero property from the WIPR model. Next, a velocity tracking controller based on the backstepping method is applied to the linearized model to follow the reference velocity trajectory while stabilizing the attitude. In addition, the proposed controller can design pre-specified transient characteristics to stabilize the upright position. On the other hand, the solution to the tracking error caused for non-minimum phase systems is to design a pre-compensator that compensates for effects of unstable zeros. To verify the effectiveness of proposed control strategy, simulations for WIPR were performed using two types of reference velocity trajectories: sigmoid-step and sine wave. As a result, the effectiveness of the proposed strategy was confirmed.