Decoupled Dynamic Control for Pitch and.pdf

3814 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 60, NO. 9, SEPTEMBER 2013 Decoupled Dynamic Control for Pitch and Roll Axes of the Unicycle Robot Jaeoh Lee, Seongik Han, and Jangmyung Lee Abstract—This paper proposes a decoupled control algorithm obtained the dynamics based upon the Lagrangian of the system for a single-wheel (unicycle) balanced robot. A unicycle robot is and implemented the gain-scheduling algorithm for robustness controlled by two independent control laws: the method involving [3]. The roll axis control of the unicycle robot has recently been mobile inverted pendulum control for the pitch axis and the method involving reaction-wheel pendulum control for the roll altered and studied by using two flying pans at both sides of the axis. We assume that both roll dynamics and pitch dynamics are robot, where the PD and PID controllers have been adopted [4]. decoupled from each other. As a result, the roll and pitch dynamics However, while there has been a lot of research focusing on are obtained independently and all interactions between them are the roll axis control of the robot, no research results have been considered disturbances. Each control law is implemented by an reported for its velocity tracking control. individual controller, i.e., fuzzy-sliding mode control for roll and linear quadratic regulator control for pitch. Fuzzy logic is utilized Over the last four years, several unicycle robots have been to compensate for the interactions between the pitch and roll implemented in the Intelligent Robot Laboratory at Pusan Na- dynamics in real time. The unicycle robot has two dc motors: