Snake robots with more joints move better through obstacles
Dense-Joint-Based Obstacle-Aided Locomotion with a Joint-Repositionable Snake Robot
Robotics
Summary
Robots that move like snakes often get stuck when trying to squeeze through complicated spaces because they don’t have enough joints along their bodies. The researchers built a new kind of snake robot that can change where its joints are along its body, allowing it to have more joints packed closely together. They found that having many joints helps the robot stay in smooth contact with obstacles, so it moves more steadily and uses less power. This approach makes snake robots better at moving through tricky environments, like cluttered rooms or rough outdoor terrain.
What this means in practice
- •For search and rescue teams: Use high-joint-density snake robots to navigate through debris-filled disaster sites with more reliable movement and less risk of getting stuck.
- •For inspection robot developers: Design snake robots with adjustable joint density to improve movement through pipes and cramped industrial environments for frequent inspections.
Authors
Kyosuke Minomo, Ryo Takahashi, Kotaro Yasui, Yasutaka Nakashima, Motoji Yamamoto, Ayato Kanada
Abstract
Obstacle-aided locomotion is a fundamental capability for snake robots to traverse complex environments. However, conventional rigid-link snake robots often suffer from stagnation or jamming caused by their low joint density (i.e., the number of joints per unit length). This results in discontinuous contact with obstacles, unlike the continuous adaptation of biological snakes. To investigate the effect of joint density on obstacle-aided locomotion performance, we utilized a joint-repositionable snake robot mechanism that decouples actuators from joints, enabling a high-density architecture. We developed two experimental models with identical total lengths but different joint densities (high-density and low-density) and conducted comparative propulsion experiments in obstacle environments with varying obstacle diameters. The experimental results demonstrate that the high-density model substantially suppresses the abrupt shifts in reaction forces that cause stagnation in the low-density model. By maintaining smooth contact points, the high-density configuration reduces power consumption and achieves stable, continuous propulsion. These results highlight high joint density as a key factor in improving the environmental adaptability of snake robots in complex terrains.