Development of Tendon-Driven Compliant Snake Robot with Global Bending and Twisting Actuation

Snake robots have been studied for decades with the aim of achieving biological snakes' fluent locomotion. Yet, as of today, their locomotion remains far from that of the biological snakes. Our recent study suggested that snake locomotion utilizing partial ground contacts can be achieved with robots by using body compliance and lengthwise-globally applied body tensions. In this paper, we present the first hardware implementation of this locomotion principle. Our snake robot comprises serial tendon-driven continuum sections and is bent and twisted globally using tendons. We demonstrate how the tendons are actuated to achieve the ground contacts for forward and backward locomotion and sidewinding. The robot's capability to generate snake locomotion in various directions and its steerability were validated in a series of indoor experiments.