Process Monitoring of a Vibration Dampening CFRP Drill Tube in BTA deep hole drilling using Fibre-Bragg-Grating Sensors

The large tool length in BTA deep hole drilling often leads to strong torsional vibrations of the tool system, leading to a reduced bore hole quality failures. When substituting steel drill tubes with tubes from composite material, the laminate structure dampens these vibrations. Secondly, the integration of sensors allow to monitor process vibrations. This contribution introduces a new sensor platform to measure process vibrations, feed force and drilling torque using Fibre-Bragg Grating Sensors. The presented experimental results focus on characteristic frequency spectra with natural torsional and compression frequencies of the CFRP drill tube, which show variations due to changed feed

Landslide monitoring using mobile device and cloud-based photogrammetry

PhD ThesisLandslides are one of the most commonly occurring natural disasters that can cause a serious threat to human life and society, in addition to significant economic loss. Investigation and monitoring of landslides are important tasks in geotechnical engineering in order to mitigate the hazards created by such phenomena. However, current geomatics approaches used for precise landslide monitoring are largely inappropriate for initial assessment by an engineer over small areas due to the labourintensive and costly methods often adopted. Therefore, the development of a costeffective landslide monitoring system for real-time on-site investigation is essential to aid initial geotechnical interpretation and assessment. In this research, close-range photogrammetric techniques using imagery from a mobile device camera (e.g. a modern smartphone) were investigated as a low-cost, non-contact monitoring approach to on-site landslide investigation. The developed system was implemented on a mobile platform with cloud computing technology to enable the potential for real-time processing. The system comprised the front-end service of a mobile application controlled by the operator and a back-end service employed for photogrammetric measurement and landslide monitoring analysis. In terms of the backend service, Structure-from-Motion (SfM) photogrammetry was implemented to provide fully-automated processing to offer user-friendliness to non-experts. This was integrated with developed functions that were used to enhance the processing performance and deliver appropriate photogrammetric results for assessing landslide deformations. In order to implement this system with a real-time response, the cloud-based system required data transfer using Internet services via a modern 4G/5G network. Furthermore, the relationship between the number of images and image size was investigated to optimize data processing. The potential of the developed system for monitoring landslides was investigated at two different real-world UK sites, comprising a natural earth-flow landslide and coastal cliff erosion. These investigations demonstrated that the cloud-based photogrammetric measurement system was capable of providing three-dimensional results to subdecimeter-level accuracy. The results of the initial assessments for on-site investigation could be effectively presented on the mobile device through visualisation and/or statistical quantification of the landslide changes at a local-scale.Royal Thai Government and Naresuan University for the scholarship and financial suppor

Noise in Marine Seismic Data

Marine seismic is a well established method to search for subsurface hydrocarbon deposits. However, the method is often limited by various sources of noise, of which flow and swell noise are the dominating types. This study takes advantage of 3-D direct numerical simulations of fluid flow combined with real life, and full scale measurements of flow and swell noise acquired on purpose built seismic streamer cables in the ocean, to study the mechanisms responsible for flow noise generation. The combined knowledge obtained by the simulations and the measurements are then put to use in order to come up with practical methods to reduce noise in seismic data. Two different paths are followed: The first is in the form of a software de-noising algorithm developed and implemented as a module in a commercial seismic processing software package. It works in the frequency domain by statistically comparing neighboring traces, and attenuates amplitudes that are found to be abnormal. The module is in daily use, and has successfully been applied to attenuate various types of noise found in both land, and marine seismic data. The second path followed to reduce the amount of noise in seismic data is to use so-called superhydrophobic surfaces. This is in the form of a coating material that can be applied to seismic streamers to reduce both drag and flow noise. The flow noise reduction capabilities of superhydrophobic surfaces is a new discovery, which holds great promise

Multi-categories tool wear classification in micro-milling

Ph.DDOCTOR OF PHILOSOPH

Probability of detection analysis for infrared nondestructive testing and evaluation with applications including a comparison with ultrasonic testing

La fiabilité d'une technique d’Évaluation Non-Destructive (END) est l'un des aspects les plus importants dans la procédure globale de contrôle industriel. La courbe de la Probabilité de Détection (PdD) est la mesure quantitative de la fiabilité acceptée en END. Celle-ci est habituellement exprimée en fonction de la taille du défaut. Chaque expérience de fiabilité en END devrait être bien conçue pour obtenir l'ensemble de données avec une source valide, y compris la technique de Thermographie Infrarouge (TI). La gamme des valeurs du rapport de l'aspect de défaut (Dimension / profondeur) est conçue selon nos expériences expérimentales afin d’assurer qu’elle vient du rapport d’aspect non détectable jusqu’à celui-ci soit détectable au minimum et plus large ensuite. Un test préliminaire est mis en œuvre pour choisir les meilleurs paramètres de contrôle, telles que l'énergie de chauffage, le temps d'acquisition et la fréquence. Pendant le processus de traitement des images et des données, plusieurs paramètres importants influent les résultats obtenus et sont également décrits. Pour la TI active, il existe diverses sources de chauffage (optique ou ultrason), des formes différentes de chauffage (pulsé ou modulé, ainsi que des méthodes différentes de traitement des données. Diverses approches de chauffage et de traitement des données produisent des résultats d'inspection divers. Dans cette recherche, les techniques de Thermographie Pulsée (TP) et Thermographie Modulée(TM) seront impliquées dans l'analyse de PdD. Pour la TP, des courbes PdD selon différentes méthodes de traitement de données sont comparées, y compris la Transformation de Fourier, la Reconstruction du Signal thermique, la Transformation en Ondelettes, le Contraste Absolu Différentiel et les Composantes Principales en Thermographie. Des études systématiques sur l'analyse PdD pour la technique de TI sont effectuées. Par ailleurs, les courbes de PdD en TI sont comparées avec celles obtenues par d'autres approches traditionnelles d’END.The reliability of a Non-Destructive Testing and Evaluation (NDT& E) technique is one of the most important aspects of the overall industrial inspection procedure. The Probability of Detection (PoD) curve is the accepted quantitative measure of the NDT& E reliability, which is usually expressed as a function of flaw size. Every reliability experiment of the NDT& E system must be well designed to obtain a valid source data set, including the infrared thermography (IRT) technique. The range of defect aspect ratio (Dimension / depth) values is designed according to our experimental experiences to make sure it is from non-detectable to minimum detectable aspect ratio and larger. A preliminary test will be implemented to choose the best inspection parameters, such as heating energy, the acquisition time and frequency. In the data and image processing procedure, several important parameters which influence the results obtained are also described. For active IRT, there are different heating sources (optical or ultrasound), heating forms (pulsed or lock-in) and also data processing methods. Distinct heating and data processing manipulations produce different inspection results. In this research, both optical Pulsed Thermography (PT) and Lock-in Thermography (LT) techniques will be involved in the PoD analysis. For PT, PoD curves of different data processing methods are compared, including Fourier Transform (FT), 1st Derivative (1st D) after Thermal Signal Reconstruction (TSR), Wavelet Transform (WT), Differential Absolute Contrast (DAC), and Principal Component Thermography (PCT). Systematic studies on PoD analysis for IRT technique are carried out. Additionally, constructed PoD curves of IRT technique are compared with those obtained by other traditional NDT& E approaches

Establishment of a novel predictive reliability assessment strategy for ship machinery

There is no doubt that recent years, maritime industry is moving forward to novel and sophisticated inspection and maintenance practices. Nowadays maintenance is encountered as an operational method, which can be employed both as a profit generating process and a cost reduction budget centre through an enhanced Operation and Maintenance (O&M) strategy. In the first place, a flexible framework to be applicable on complex system level of machinery can be introduced towards ship maintenance scheduling of systems, subsystems and components.;This holistic inspection and maintenance notion should be implemented by integrating different strategies, methodologies, technologies and tools, suitably selected by fulfilling the requirements of the selected ship systems. In this thesis, an innovative maintenance strategy for ship machinery is proposed, namely the Probabilistic Machinery Reliability Assessment (PMRA) strategy focusing towards the reliability and safety enhancement of main systems, subsystems and maintainable units and components.;In this respect, the combination of a data mining method (k-means), the manufacturer safety aspects, the dynamic state modelling (Markov Chains), the probabilistic predictive reliability assessment (Bayesian Belief Networks) and the qualitative decision making (Failure Modes and Effects Analysis) is employed encompassing the benefits of qualitative and quantitative reliability assessment. PMRA has been clearly demonstrated in two case studies applied on offshore platform oil and gas and selected ship machinery.;The results are used to identify the most unreliability systems, subsystems and components, while advising suitable practical inspection and maintenance activities. The proposed PMRA strategy is also tested in a flexible sensitivity analysis scheme.There is no doubt that recent years, maritime industry is moving forward to novel and sophisticated inspection and maintenance practices. Nowadays maintenance is encountered as an operational method, which can be employed both as a profit generating process and a cost reduction budget centre through an enhanced Operation and Maintenance (O&M) strategy. In the first place, a flexible framework to be applicable on complex system level of machinery can be introduced towards ship maintenance scheduling of systems, subsystems and components.;This holistic inspection and maintenance notion should be implemented by integrating different strategies, methodologies, technologies and tools, suitably selected by fulfilling the requirements of the selected ship systems. In this thesis, an innovative maintenance strategy for ship machinery is proposed, namely the Probabilistic Machinery Reliability Assessment (PMRA) strategy focusing towards the reliability and safety enhancement of main systems, subsystems and maintainable units and components.;In this respect, the combination of a data mining method (k-means), the manufacturer safety aspects, the dynamic state modelling (Markov Chains), the probabilistic predictive reliability assessment (Bayesian Belief Networks) and the qualitative decision making (Failure Modes and Effects Analysis) is employed encompassing the benefits of qualitative and quantitative reliability assessment. PMRA has been clearly demonstrated in two case studies applied on offshore platform oil and gas and selected ship machinery.;The results are used to identify the most unreliability systems, subsystems and components, while advising suitable practical inspection and maintenance activities. The proposed PMRA strategy is also tested in a flexible sensitivity analysis scheme

30th International Conference on Condition Monitoring and Diagnostic Engineering Management (COMADEM 2017)

Proceedings of COMADEM 201

Intelligent Systems

This book is dedicated to intelligent systems of broad-spectrum application, such as personal and social biosafety or use of intelligent sensory micro-nanosystems such as "e-nose", "e-tongue" and "e-eye". In addition to that, effective acquiring information, knowledge management and improved knowledge transfer in any media, as well as modeling its information content using meta-and hyper heuristics and semantic reasoning all benefit from the systems covered in this book. Intelligent systems can also be applied in education and generating the intelligent distributed eLearning architecture, as well as in a large number of technical fields, such as industrial design, manufacturing and utilization, e.g., in precision agriculture, cartography, electric power distribution systems, intelligent building management systems, drilling operations etc. Furthermore, decision making using fuzzy logic models, computational recognition of comprehension uncertainty and the joint synthesis of goals and means of intelligent behavior biosystems, as well as diagnostic and human support in the healthcare environment have also been made easier