Novel methods of object recognition and fault detection applied to non-destructive testing of rail’s surface during production

A series of rail image inspection algorithms have been developed for Tata Steels Scunthorpe rail production line. The following thesis describes the contributions made by the author in the design and application of these algorithms. A fully automated rail inspection system that has never been implemented before in any such company or setup has been developed. An industrial computer vision system (JLI) already exists for the image acquisition of rails during production at a rail manufacturing plant in Scunthorpe. An automated inspection system using the same JLI vision system has been developed for the detection of rail‟s surface defects during manufacturing process. This is to complement the human factor by developing a fully automated image processing based system to recognize the faults with an improved efficiency and to allow an exhaustive detection on the entire rail in production. A set of bespoke algorithms has been developed from a plethora of available image processing techniques to extract and identify components in an image of rail in order to detect abnormalities. This has been achieved through offline processing of the rail images using the blended use of different object recognition and image processing techniques, in particular, variation of standard image processing techniques. Several edge detection methods as well as adapted well known Artificial Neural Network and Principal Component Analysis techniques for fault detection on rail have been developed. A combination of customised existing image algorithms and newly developed algorithms have been put together to perform the efficient defect detection. The developed system is fast, reliable and efficient for detection of unique artefacts occurring on the rail surface during production followed by fault classification on the rail imaging system. Extensive testing shows that the defect detection techniques developed for automated rail inspection is capable of detecting more than 90% of the defects present in the available data set of rail images, which has more than 100,000 images under investigation. This demonstrates the efficiency and accuracy of the algorithms developed in this work

The development of an autonomous robotic inspection system to detect and characterise rolling contact fatigue cracks in railway track

At present, high speed dual purpose rail/road vehicles employing fixed non-destructive testing (NDT) sensors are used to inspect rails. Due to the uncertainties in characterisation of the defects when they are detected at high speed, manual re-visiting of the defects by expert operators is required before any decision regarding track maintenance is made. This research has been driven by a desire from the rail industry for a robotic system performing faster than human operators and being capable to both detect and characterise rolling contact fatigue (RCF) cracks in rails with the aim of automating the existing manual inspection and enhancing its accuracy and reliability. This thesis combines expert systems technologies with robotic NDT to fulfil this aspiration. A great deal of effort has been spent to develop a robotic inspection trolley which can automatically detect and characterise the RCF cracks in rails using an alternating current field measurement (ACFM) sensor. It uses a rule based expert system (RBES) proposed to control the robotic trolley and more importantly process ACFM data for both detecting and sizing defects. The developed system can detect the possible presence of defects in railway tracks at high speed pass (5-20 km/h) and can automatically return to an identified defect location to perform a slower and more detailed scan (up to 20 mm/s) across a rail section to determine the size, depth and number of cracks present in that section

Image processing techniques for the detection and characterisation of features and defects in railway tracks

This thesis describes the research that led to the development of a machine vision system in collaboration with TATA, UK and Sheffield Supertram. This was part of a European initiative for Predictive Maintenance employing non-intrusive inspection and data analysis known as PM’n’Idea. The hardware and software design, construction, and evaluation of a prototype for predictive maintenance are presented. The prototype was tested on Sheffield and Warsaw’s tram systems. The prototype has been designed with due account of a specified set of environmental constraints such as a high level of vibrations and space restrictions of the target trams. Special computer vision techniques have been specifically developed to be used with the prototype. Various image processing techniques and algorithms have been evaluated for the purpose of detection and characterisation of a series of rail abnormalities and faults. The system described in this thesis makes use of a number of standard and modified image processing techniques, not only to alleviate the requirements for manual inspections, but also to allow continuous monitoring and tracking of any defects or abnormalities in a rail track. Currently, detecting defects in their earlier stages can only be achieved by using close visual inspection i.e. line walking. Extensive testing and evaluation of the performance of the prototype inspection system at Sheffield Supertram indicated that the system was able to detect abnormalities with a resolution down to 0.1 mm. Evidence of the classification rates for the standard and modified algorithms that are implemented in the system are presented in this thesis. The algorithms developed show an average success rate of 88.9% in detecting surface bound abnormalities

Time Localization of Abrupt Changes in Cutting Process using Hilbert Huang Transform

Cutting process is extremely dynamical process influenced by different phenomena such as chip formation, dynamical responses and condition of machining system elements. Different phenomena in cutting zone have signatures in different frequency bands in signal acquired during process monitoring. The time localization of signal’s frequency content is very important. An emerging technique for simultaneous analysis of the signal in time and frequency domain that can be used for time localization of frequency is Hilbert Huang Transform (HHT). It is based on empirical mode decomposition (EMD) of the signal into intrinsic mode functions (IMFs) as simple oscillatory modes. IMFs obtained using EMD can be processed using Hilbert Transform and instantaneous frequency of the signal can be computed. This paper gives a methodology for time localization of cutting process stop during intermittent turning. Cutting process stop leads to abrupt changes in acquired signal correlated to certain frequency band. The frequency band related to abrupt changes is localized in time using HHT. The potentials and limitations of HHT application in machining process monitoring are shown

Integrating BIM and GIS for design collaboration in railway projects

Collaboration is essential to achieve project targets and minimising rework in any project including railway projects. The railway project is considered as a megaproject that requires effective collaboration in order to achieve efficiency and effectiveness. To ensure that the railway continues to provide safe, reliable, cost-effective services, and remains environmentally friendly while driving economic growth, engaging new technologies and new types of work models are required. Among these technologies, Building Information Modelling (BIM) and Geographic Information Systems (GIS) are recent technologies that support collaboration. However, using these technologies to achieve effective collaboration is challenging, especially in railway projects as they are amongst the most complicated projects and often numerous parties are involved in making important decisions. Currently, there is a lack of evidence-based guidelines or processes for effective collaboration in railway projects throughout their design stage. Therefore, this thesis has focused on developing a process model to improve collaboration in the design stage of railway projects using BIM and GIS. This research adopted a mixed-methods approach to examine and identify the issues that hinder collaboration in railway projects to assist in developing theBIM and GIS-enabled collaboration process model. An online questionnaire was designed and distributed to professionals to assess the state-of-the-art in BIM and GIS followed by two rounds of in-depth interviews with experts. The first round aimed to identify collaboration issues and consisted of 15 in-depth, face to face and videoconference/telephone interviews; while the second round consisted of 10 in-depth interviews to identify the process model components of the collaborative process using IDEF technique.The questionnaire data were analysed using descriptive statistics and statistical tests (for example, Regression analysis, Wilcoxon Signed Ranks and Kruskal-Wallis Test). The results showed a lack of training in BIM and GIS and identified collaboration as a significant factor for railway projects, but there were many challenges to achieve effective collaboration. These challenges have been further investigated during the first round of interviews using content and thematic analysis. The results revealed that the most common challenges were getting the right information at the right time for the right purposes followed by resistance to change. Furthermore, the findings indicated that developing a process model, based on a clear plan of work demonstrating the collaboration process, is a potential solution to tackle these challenges. Thus, a Collaborative Plan of Work (CPW) has been developed through combining the RIBA (Royal Institute of British Architects) Plan of Work and the GRIP (Governance for Railway Investment Projects) stages. This CPW will be the basis to develop a process model for BIM and GIS-enabled collaboration. The results from the second round of the interviews identified the process model components which are: key players’ roles and responsibilities, tasks (BIM and GIS Uses), BIM and GIS-based deliverables, and critical decision points for collaborative process design. Moreover, this process model was formulated utilising Integrated DEFinition (IDEF) structured diagramming techniques (IDEF0 and IDEF3).In conclusion, the process model of the collaboration process and the integrated implementation of BIM and GIS sets out role and responsibilities, deliverables, and key decision points. Finally, the research outcomes have been validated through a focus group and interviews with professionals in the biggest Railway company where the proposed process model was operationalised using a commercial Common Data Environment platform (viewpoint 4project). From their discussion, feedback and recommendations the IDEF processes model have been refined. It is concluded that such a process is crucial for effective collaboration in railway projects as it enables the management of the design process in terms of technologies used, activities, deliverables, and decision points. Therefore, the research findings support the notion that BIM and GIS can help to achieve effective collaboration by delivering the right information at the right time for the right purposes. As a result, they help to achieve the projects’ objectives efficiently in terms of time, cost and effort.</div

Stability and change in large technical systems: the privatisation of Great Britain's railways

Established infrastructure systems, such as telecommunications, energy and transportation, play an important economic and social role in the societies they support. Recent infrastructure privatisations and restructurings provide opportunities for improving our understanding of how change occurs in well-established mature systems. Some outcomes, including accidents and failures, have taken system-builders and policy-makers alike by surprise. This research seeks to improve understanding of infrastructure system change by studying a momentum changing event: the privatisation and restructuring of Great Britain’s railway system. The Multi-Level Perspective (MLP) and Large Technical Systems (LTS) theory are used together to examine system development before, during and after restructuring. A novel method is developed using LTS theory to structure data generation from contemporarily written archive sources. Two empirical studies are conducted. The first study analyses the gradual development of this mature system; it highlights the importance of the installed system in development and identifies several system-builders. The second study considers changes in system development that occurred across system privatisation and restructuring; it finds that changes emerged in actors and in activity within the socio-technical regime and it highlights some critical changes linked to later system failure. This work provides three contributions to existing research. (1)The method developed provides a systematic approach to studying established LTS across the broad scope and long periods necessary to capture change; it has the potential to be applied in other studies and could facilitate cross-sector and cross-study comparisons. (2)An extension of LTS theory is proposed that improves its application to the cases of established infrastructure systems and can enhance understanding of the way they change. (3)In considering potential system transformation of the system privatisation, the use of LTS and MLP framework is advocated. LTS theory is used to operationalise the socio-technical regime concept to address some of the limitations of the MLP framework.Open Acces

Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version