No abstract

In the case of damp and wet pipes, pipe inspection robots using pneumatic actuators offer advantages such as no electrical leakage and short circuit. In the previous study, a robot consisting of sliding/bending mechanisms using parallel arranged three extension type flexible pneumatic actuators and two holding mechanisms was successfully developed. In order to use the robot in thinner pipe, a novel and simpler propulsion mechanism utilising the difference of frictional force moving forward and backward are proposed and tested in this work. There are two mechanisms, which are “wriggling type” and “cilia type”. The “wriggling type” mechanism moves forward by wriggling its body while the “cilia type” mechanism moves by using plate type cilia that covered on the mechanism. Both mechanisms have been tested in the pipeline. As a result, it can be confirmed that the cilia type propulsion mechanism can travel in the pipe with accumulated water. It can be found that the mechanism can easily travel through corners while twisting its body by giving bending motion toward any direction.

To reduce the inspection cost of water supply pipe, various pipe inspection robots have been developed. In the previous study, a novel pipe inspection robot using a flexible pneumatic cylinder and pipe holding mechanism that could move forward along to the pipe by changing the robot's body naturally was proposed and tested. In this paper, to improve its mobility and responsibility, a pipe holding mechanism using an extension type flexible pneumatic actuator whose volume change is smaller than the previous one using a balloon is proposed and tested. In addition, to change the travelling direction of the robot, a compact bending unit using shorter extension type flexible actuators is proposed and tested. As a result of its driving test, the tested thin holding mechanism can hold a pipe without increasing its longitudinal length.  The tested bending unit can bend 90 deg. toward every radial direction with the length of the unit becomes two-third short from the previous one.

No abstract