Obstacle-Aided Locomotion of a Snake Robot Using Piecewise Helixes

A non-wheeled snake robot can propel itself by pushing against obstacles. This is called obstacle-aided locomotion. To expand the exploration range of a snake robot using this method, it is preferable to utilize obstacles that are both on the ground and by the side or above. To achieve these goals, we propose an obstacle-aided locomotion using piecewise helixes. This target shape comprises grounding and obstacle-contacting parts. The length and shape of the grounding part can be changed from a straight line to a circular arc. The height of the obstacle-contacting part can be changed or its direction can be reversed. The robot can adapt to various obstacles by appropriately changing its body shape. In addition, we propose a snake robot locomotion in a flat ground using the same shape as that used for obstacle-aided locomotion. This involves a combination of shift control and rolling motion. The robot can move in a straight line in the forward or lateral direction or can turn in a circular arc using the proposed method. Finally, experiments that confirm the effectiveness of the proposed method are presented

Hoop-Passing Motion for a Snake Robot to Realize Motion Transition Across Different Environments

A snake robot performs diverse motions. To realize a wide range functions in a complex environment, it is necessary to transition between various motions suited to each environment. In this article, we propose a method of transitioning the motion of a snake robot across different environments to expand the application environment of the robot. We first find that the motion at the connection point between two motions must coincide with the tangential movement during motion transition across different environments. We then design a gait called the circular pedal wave. This circular pedal wave allows a hoop-passing motion in which the whole body moves as if it is passing through a virtual hoop fixed in space in sequence from its head through combination with a proposed shift part. The hoop-passing motion allows motion transition across different environments. We propose three application examples of this hoop-passing motion, namely passing through a hole in a wall, entering an underfloor, and attaching to a ladder. We report on experiments conducted to verify the effectiveness of the proposed method and to realize the described motions