A New Bio-Inspired Hybrid Cable-Driven Robot (HCDR) to Design More Realistic Snakebots

Bioinspired robots are useful tools to study complex biomechanical processes of animal locomotion. Key movements and kinematic parameters are under the control of experimenters, which is impossible to perform when experimenting with living animals. The primary challenge to test biological hypotheses is designing realistic robots taking inspiration from swimming snakes. Yet, underlying biomechanics of undulatory swimming i.e., anguilliform swimming, remains poorly understood. Many of underwater snakebots are made of rigid segments that form a broken-line system, unlike the skeleto-muscular systems of living snakes include more than 200 vertebrae, conferring an extreme fluidity. This paper introduces a novel design based on hybrid continuum cable driven robot (HCDR) developed through interaction with biologists and roboticists. This Biology-Push design significantly increases the fluidity and freedom of the robot's motion. Thus, improved mimic snake's locomotion is given using cable-driven to represent linkages between muscles and vertebrae providing good fluidity. In addition, the association of rigid and flexible parts allows a homogeneous distribution of actuators and masses to design autonomous swimming snake robot. Combining literature data and kinematic of swimming snakes’ analyses, we implemented a kinematic model to control prototype’ motion in both a plane and a volume. Finally, a comparative study between the device kinematics and the snake's movements is carried out.