H. Nishii et al., VIBRATION CONTROL OF A WHEELED MOBILE ROBOT BASED ON DISTURBANCE OBSERVER, JSME international journal. Series C, dynamics, control, robotics, design and manufacturing, 36(4), 1993, pp. 442-447
The 2-wheel mobile robot features the ability to easily perform spin t
urns and transverse motion. The problem, however, is that the robot is
prone to slow damping vibration in the turning direction. Usually, a
guiding algorithm controls the position and heading only. Without cons
idering dynamics, it is difficult to suppress vibration. We propose a
method to prevent vibration by taking the dynamics of the robot into c
onsideration. A mathematical model of the robot demonstrates that the
turning accelerative and elastic torques act reactively on the motors
of the left and right drive wheels. Although these two torques act on
each motor with equal magnitude, they have different signs. A differen
ce in the reactive torques occurs, and this is thought to be the main
cause of vibration. Our proposed method is to suppress vibration by im
posing feedback of the difference of the reactive torques. Experiments
have shown significant results in suppressing vibration by means of t
his technique.