A Mechanism of Single Actuator Snakeboard Robot and its Curving Motion Generation

This paper reports a new mechanism of a wheeled robot moving by the single actuator. This mechanism is inspired by the two-wheeled skateboard, or snakeboard. There, the control inputs are usually considered as the following three: the steering angles of the front and the rear wheels, and the torque for the rotor rotation. To propel a snakeboard with the smaller number of actuators, two steering orientations of the wheels are coupled each other at first so as to rotate in the same amount to the opposite direction synchronously. Next, the rotation of the steering orientations are connected to the rotor via the torque limiter. In addition, the stoppers are introduced to restrict and to maintain the steering orientation of the wheels. Curving the path of the robot with this mechanism to the side, the position-based control of the rotor with a drifting sine wave reference is newly proposed. The behaviors according to the control law as well as the effect of this mechanism are confirmed by a robot we construct. Consequently, some curving motion with different curvature are demonstrated. Finally, a principle of the curving motion is discussed based on the theoretical and experimental insights.