볼 밸런싱 로봇의 경로 추종 및 자세제어를 위한 외란 관측기 기반 비선형 제어

Abstract

This paper proposes a disturbance observer based nonlinear control method to realize the trajectory tracking and balancing of a ball balancing robot with external disturbances. As a ball balancing robot is underactuated and involves nonlinear couplings, it is difficult to design a controller that can simultaneously realize trajectory tracking and balancing. To address this problem, we introduce a virtual angle as a the reference angle for the trajectory tracking of the robot. In this manner, simultaneous trajectory tracking and balancing of the ball balancing robot can be realized using a single loop controller. In addition, we develop a disturbance observer to estimate the external disturbances and design the controller using the dynamic surface control method. According to the Lyapunov stability theory, all the errors are noted to be uniformly ultimately bounded. The simulation results demonstrate the performance of the proposed control system.