Centipede Inspired Modular Robot for Obstacle Terrain Locomotion

Abstract

In the field of mobile robotics, more diverse tasks in unstructured environments are being assigned to today’s robots as the advancement of technology is bringing more robust characteristics to their autonomous operation capabilities. In unstructured environments such as outdoors where uneven terrains are present, the obstacle traversability of mobile robot takes highly influential role in deciding its autonomous capability. Terrains in the nature have obstacles with varying levels of required traversability. Hence, three main locomotion system types being used in mobile robots for traversing diverse terrains include wheeled, tracked, and bio-inspired legged designs. Previous portable legged robots attained fast and incredibly mobile locomotion result over rough terrains by utilizing simple-to-control low degree of freedom legs with open loop control scheme where legs form statically stable posture and passively respond like a spring to incoming terrain perturbations. However, most of the previous legged robots for rough terrain locomotion have mostly adapted single rigid body structures (SRBS). Such design inherently lacks body adaptation characteristic over uneven terrains especially with legs having low degree of freedom. This problem makes stable body orientation harder to maintain and results in less terrain traversability of the robot. In this work, we took the biomimetic design approach from centipedes with the idea of modular body structure that can flex for better adaptation over uneven terrains. The centipede inspired robot prototype, ZineDyn is proposed with spring inserted joints for passive adaptation of body over uneven terrains. Also, by taking advantage of one distinct gait pattern found in centipedes; wave gait, we designed a simple multi-leg actuation method using a single motor powered flexible drive shaft that runs along the length of the robot. The locomotion of the prototype was experimented over several obstacle courses and speed equal...