Review of the Latest Research on Snake Robots Focusing on the Structure, Motion and Control Method

Unlike other types of robots, the snake robot performs unique motions and can move on various terrains such as gravel, stairs, and pipes. Therefore, snake robots are used as exploration robots, rescue robots, and disaster robots. However, the snake robot requires to choose actuators, sensors, and controllers appropriately for overcoming the real environment by using various types of gait. In this paper, we summarized research trends of snake robots for understanding the state of the art technologies of snake robots. We focused on the various development of the snake robots based on previous snake robots’ literature. To look more closely at these research trends, we introduced trends of motion, actuators, sensors, kinematic structure design, control method and application that are related with the snake robots. Snake robots can conduct several motions such as sine wave, side winding, rolling, and so on. These motions are generated by servo motors, DC motors, pneumatic actuators, and smart materials like SMA, IPMC, etc. Also, snake robots require certain data from sensors and proper kinematic structure design to achieve their purposes of operation. Sensors such as camera, force sensor, distance sensor, and kinematic structure design such as passive wheel and motorized wheel can be applied in snake robot for implementing the function or increasing the driving performance. Based on these physical components, the control method is important for operating the snake robot. Navigating algorithms and overcoming terrains with restrictions on movement have been studied with a various control methods.