Use this URL to cite or link to this record in EThOS:
Title: Robotic pipe inspection : system design, locomotion and control
Author: Blyth, William Alexander
ISNI:       0000 0004 7427 7301
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
The structural integrity of an industrial plant is a key safety and economic consideration for operators in many sectors including: power generation, oil and gas and petrochemical. To ensure safe operation, the plant often undergoes scheduled inspection using Non-Destructive Testing (NDT) methods to detect, size and locate defects such as cracks in welds or corrosion, with the accuracy and repeatability of inspections being critical to monitoring defect growth. Considering the significant cost of plant downtime for inspection, there is an economic benefit to be gained by increasing the speed of inspections, alongside reducing access requirements. Robotic NDT aims to address some of these issues, with an increase in inspection speed, repeatability and accuracy, and the added potential to remove human operators from hazardous environments. Conventional mobile climbing robots are limited by their manoeuvrability, with lateral drift, gravitational effects and continuous motion being particular issues that remain challenging in the context of complex geometries. This thesis aims to investigate the potential for enhanced mobility in mobile climbing robots to precisely follow inspection paths on cylindrical surfaces in various orientations, without drift. This has been done through the development of a reduced actuation mecanum wheel platform, using magnetic adhesion and external position encoding, allowing full translational motion whilst using kinematic and geometric constraints to prevent rotation. Through dynamic modelling of the platform, a model based control structure has been synthesised, allowing for improved consistency of performance in all orientations. The platform has been applied to representative inspection paths and used to conduct ultrasonic inspection of test samples, with the capability to correct for lateral drift and cover large inspection areas, improving the inspection accuracy and area coverage over conventional systems, without requiring operator intervention.
Supervisor: Rodriguez y Baena, Ferdinando ; Cegla, Frederic Sponsor: Phoenix Inspection Systems Limited ; Engineering and Physical Sciences Research Council
Qualification Name: Thesis (D.Eng.) Qualification Level: Doctoral