Obstacle Avoidance of Snake Robot Moving with A Novel Gait Using Two-Level PID Controller

In this paper, we introduce a novel locomotion mode (gait) for 2D snake robots. The idea behind this new gait is to control orientation of snake robot by head link and use other links as a means of driving the robot. When snake robot moves using this gait, head link always looks at direction of motion and can therefore receive much better information of target and obstacles in the direction of motion. This will significantly improve the ease of robot control which is critical in the case of search and rescue operations. Finding the proposed gait parameters is an optimization problem that we solve it using genetic algorithm (GA). We then propose a two-level PID controller to guide snake robot to target while avoiding obstacles. The lower level PID controller controls actuators input torque while the higher level PID controller controls orientation of the head link. Simulation results confirm the effectiveness of the proposed method.