LIZARD-INSPIRED STANDING WAVE QUADRUPEDAL LOCOMOTION FOR SOFT IN-PIPE NAVIGATION ROBOT

Numerous studies have been conducted for in-pipe navigation robots with the sole purpose of navigating through and inspecting pipelines. Most in-pipe navigation robots are of the rigid type. There is an increasing trend to incorporate soft-robotic technology into in-pipe navigation robots. However, most of the soft in-pipe navigation robots’ design and locomotion are inspired by inchworm and earthworm, leaving other potential methods of locomotion largely untapped. This paper describes the design and development of a lizard-inspired soft robot to investigate the feasibility of using the lizard-inspired standing wave quadrupedal Locomotion and head stabilization to steadily navigate inside a pipeline. This soft robot is designed and simulated in Solidworks 3D modelling software and fabricated using SORTA-Clear 40 soft silicone rubber using a moulding technique. The soft robot is actuated using pressurized air. A series of experiments are conducted to evaluate the performance of the robot’s navigation inside straight pipes of different diameters as well as through pipe corners of different angles. Based on the experiment, the robot achieves a speed of 2.02, 2.77, and 2.33 mms⁻¹ inside straight pipes of 50 mm, 60 mm, and 70 mm in diameter, respectively. For navigation through 45° and 90° pipe corners, a navigation speed of 2.94 and 0.73 mms⁻¹ has been achieved, respectively. The robot has also demonstrated good head stability with an average side-to-side movement of 3.6 mm from the centre of the pipe and an average head rotation of 6.1° during the locomotion. The results demonstrated the potential of using lizard-inspired locomotion for in-pipe navigation, which has been reported in the literature before.