Design and evaluation of a continuum robot with extendable balloons

In this thesis, a novel continuum robot actuated with extendable balloons is presented. The robot is composed of two parts; the tip and the flexible shaft. The balloons are attached to the tip from their slack sections. The utilized balloons are able to extend much in length without having a significant change in diameter. Employing two balloons in an axially extendable, radially rigid flexible shaft, radial strain becomes constricted; allowing free elongation. As inflated, the balloons apply a force on the wall of the tip, on which they are attached. This force pushes the tip forward, enabling the robot to elongate in longitudinal direction and take some of the slack back. The air is supplied to the balloons by an air compressor and its flow rate to each balloon can be independently controlled by solenoid valves via Pulse Width Modulation (PWM) signals. Changing the air volumes differently in each balloon orients the robot, allowing navigation in substantially long and narrow environments. Mechanical properties of different balloons are analyzed during inflation. Afterwards, the robot is subjected to open field and maze-like environment navigation tests. The proposed type of robots can be used in many applications such as exploratory or medical purposes by having necessary tools attached to the tip.