Control of a Snake Robot for Ascending and Descending Steps

This paper proposes control method for a snake robot to ascend and descend steps. In a multiplane step environment, it is necessary for locomotion to transfer from one plane to another. When a snake robot moves, it touches several planes as its body is long and thin. In this paper, we propose a control method to track the trajectory of a snake robot in a step environment. We decomposed the 3-D motion of the robot into two simple models by introducing an assumption that simplifies the model and controller, and derive a model of the robot as a hybrid system with switching. The control method consists of a tracking controller, a method for shifting the robot's part connecting the planes, and active lifting to control the shape of the robot. Ascent and descent experiments confirm the effectiveness of the proposed controller and the method for shifting the connecting part of the robot's body.