Research on a Tubular Climbing Robot Induced by Tri-tube Soft Actuators

In this paper, a pipe robot consisted of iris expansion mechanism and tri-tube soft actuators, which simulates insect crawling mode, is proposed. We used 3D-printing technology to fabricate the main structure of the robot. For displaying the detail working mechanism, the movement process diagram has been proposed. In order to identify the working ability, we investigated the operation space of the guiding mechanism based on equal continuous hypothesis and the adhesive output of the iris mechanism. The related performance experiments have been carried out to verify the analysis as well. Our results showed that the robot fixed by iris mechanism to the pipe could adapt to pipes with various diameters ranging from 80 to 120 mm (about 1.5 times as its original size). The guiding mechanism composed of three hoses driven by motors was easy to bend 90 degrees, which satisfied the curved pipe environments. The biggest characteristic of our robot is the flexible structure and adhesive methods, which gets rid of the limitation of air source and air pipe to the robot.