Study of a mobile robot which can shift from one horizontal bar to another using vibratory excitation

Abstract

A double-pendulum-type mobile robot, which can shift laterally from one horizontal bar to an adjacent bar, has been studied. The robot is equipped with pivoted double-link arms and grippers installed on the free ends of the arms. First, one arm of the robot grasps one of several bars arranged horizontally at regular intervals with its gripper, and the second arm is immobile, hanging from its upper pivoted end. When the latter is swung by an actuator following the control path, vibratory excitation is induced in the robot. As a result of this excitation, the gripper end of the second arm is swung up to the neighboring bar, at which point the gripper grasps the bar, and the first arm's gripper releases the original bar. Then the robot moves laterally by one pitch of the bars, and shifts continuously through the bars by repeating the sequerice. It is confirmed by experiments as well as by computer simulation that the robot can shift through the horizontal bar array using excitation of the system. The concept of control paths, proposed here, is very useful. Furthermore, this mobile robot provides a unique example of dynamic interference problems between arms with and without an actuator in order to indute excitation in the entire system.