Parallel Platform-Based Robot for Operation in Active Water Pipes

This thesis presents a novel design for a pipe inspection robot. The main aim of the design has been to allow the robot to operate in a water pipe while it is still in service. Water pipes form a very crucial part of the infrastructure of the world we live in today. Despite their importance, water leakage is a major problem suffered by water companies worldwide, costing them billions of dollars every year. There are a wide variety of different techniques used for leak detection and localisation, but no one method is capable of accurately pinpointing the leak location and severity in all pipe conditions with minimal labour. A survey of existing pipe inspection robots showed that there have been many designs implemented that are capable of navigating the pipeline environment. However, none of these were capable of fully autonomous control in a live water pipe. It was concluded that an autonomous pipe inspection robot capable of working in active pipelines would be of great industrial benefit as it would be able to carry a wide range of sensors directly to the source of the leak with minimal, if any, human intervention. An inchworm robot prototype was constructed based on a Gough-Stewart parallel platform. The robot’s inverse kinematics equations were derived and a simulation model of the robot was constructed. These were verified using a motion capture suite, confirming that they are valid representations of the robot. The simulation was used to determine the robot’s movement limitations and minimum bend radius it could navigate. Several CFD simulations were carried out in order to estimate the maximum fluid force exerted on the robot. It was found that the robot’s design successfully minimised the fluid force such that off-the-shelf actuators had the capability to overcome it. The prototype was successfully tested in both a straight and bent pipe, demonstrating its ability to navigate a dry pipe environment. Overall, the robot prototype served as a successful proof of concept for a design of pipe inspection robot that would be capable of operating in active pipelines