Self-moving pneumatic unit for ducts inspection tasks

The paper shows the results of a theoretical and experimental research activity oriented to the design and the realization of a of a low cost pneumatronic prototype, proposed for tasks of pipes and ducts inspection. The prototype consists on a self-moving pneumatic unit conceived to emulate the grub's motion: variable geometry components are deformed under the action of pneumatic power supply, following a programmable logic actuation. A fluidic muscle is used to generate the motion and two deformable air chambers are arranged at the ends of the muscle in order to assure the anchorage to the internal pipe wall. The motion of the pneumatic robot is related to the pneumatic sequence involving inflating and deflating of the air-chambers and to the actuation to the muscle. It is required that the user can actuate in any moment the robot and manage the advancing and withdrawal, with flexible dwells. Aspects related to design procedure followed to optimize the geometry of the head, the solution of problems related to anomalous deformation of the fluidic muscle and the implementation of flexible motion laws, the comparison with other self-moving prototypes are discussed.