Crawling gait design for a caterpillar-inspired robot with tendon-driven flexible bending segments

Soft crawling robots can potentially access locations that are unreachable by humans and traditional rigid robots, playing a crucial role in conducting missions like environmental monitoring or search and rescue. Due to their flexible body structures, soft robots can adapt to uncertain environments and operate safely in contact with humans. We present a new design for a caterpillar-inspired soft robot in the form of a series of 3D printed flexible tendon-driven bending segments with individual motor control. A constant-curvature quasi-static kinematic model of the robot locomotion is developed, and we describe periodic gait inputs that coordinate bending in multiple segments to lift the prolegs and move forward in a traveling-wave motion. We present simulations and experimental results for locomotion in a straight line, along with experimental demonstration of a modified segment design with an additional degree of freedom for steering navigation.