Cloud manufacturing system for sheet metal processing

Cloud computing is changing the way industries and enterprises run their businesses. Cloud manufacturing is emerging as an approach to transform the traditional manufacturing business model, while helping the manufacturer to align production efficiency with its business strategy, and creating intelligent factory networks that enable collaboration across the whole enterprise. Many production planning and control (PPC) problems are essentially optimisation problems, where the objective is to develop a plan that meets the demand at minimum cost or maximum profit. Because the underlying optimisation problem will vary in the different business and operation phases, it is important to think about optimisation in a dynamic mechanism and in a number of interlinked sub-problems at the same time. Cloud manufacturing has the potential to offer decision support as a service and medium of communication in PPC. To solve these problems and produce collaboration across the supply chain, this paper provides an overview of the state of the art in cloud manufacturing and presents a model of cloud-based production planning and production system for sheet metal processing.fi=vertaisarvioitu|en=peerReviewed

Robotic workcell analysis and object level programming

For many years robots have been programmed at manipulator or joint level without any real thought to the implementation of sensing until errors occur during program execution. For the control of complex, or multiple robot workcells, programming must be carried out at a higher level, taking into account the possibility of error occurrence. This requires the integration of decision information based on sensory data.Aspects of robotic workcell control are explored during this work with the object of integrating the results of sensor outputs to facilitate error recovery for the purposes of achieving completely autonomous operation.Network theory is used for the development of analysis techniques based on stochastic data. Object level programming is implemented using Markov chain theory to provide fully sensor integrated robot workcell control

Ubiquitous Integration and Temporal Synchronisation (UbilTS) framework : a solution for building complex multimodal data capture and interactive systems

Contemporary Data Capture and Interactive Systems (DCIS) systems are tied in with various technical complexities such as multimodal data types, diverse hardware and software components, time synchronisation issues and distributed deployment configurations. Building these systems is inherently difficult and requires addressing of these complexities before the intended and purposeful functionalities can be attained. The technical issues are often common and similar among diverse applications. This thesis presents the Ubiquitous Integration and Temporal Synchronisation (UbiITS) framework, a generic solution to address the technical complexities in building DCISs. The proposed solution is an abstract software framework that can be extended and customised to any application requirements. UbiITS includes all fundamental software components, techniques, system level layer abstractions and reference architecture as a collection to enable the systematic construction of complex DCISs. This work details four case studies to showcase the versatility and extensibility of UbiITS framework’s functionalities and demonstrate how it was employed to successfully solve a range of technical requirements. In each case UbiITS operated as the core element of each application. Additionally, these case studies are novel systems by themselves in each of their domains. Longstanding technical issues such as flexibly integrating and interoperating multimodal tools, precise time synchronisation, etc., were resolved in each application by employing UbiITS. The framework enabled establishing a functional system infrastructure in these cases, essentially opening up new lines of research in each discipline where these research approaches would not have been possible without the infrastructure provided by the framework. The thesis further presents a sample implementation of the framework on a device firmware exhibiting its capability to be directly implemented on a hardware platform. Summary metrics are also produced to establish the complexity, reusability, extendibility, implementation and maintainability characteristics of the framework.Engineering and Physical Sciences Research Council (EPSRC) grants - EP/F02553X/1, 114433 and 11394

On delay stable communications in asynchronous networks

This dissertation defines a frame forwarding technique offering a fixed delay to a subclass of traffic in closed industrial control networks. In these networks bandwidth is dedicated to periodic traffic supporting tight inter-process control and control loop communication. Ideally periodic traffic arrival will have minimal delay-jitter with constant realized delays. This simplifies the implementation of connected control devices. Furthermore networks are simplified with asynchronous node and switch operation. Switch designs are simplified as there is no dependence on adjacent switch clock operation. Correct network function only relies on switches directly traversed by each flow and is not dependent on complex clock synchronization mechanisms. Existing packet scheduling schemes that attempt to minimize delay-jitter, suffer from either requiring inter-switch clock coordination (i.e. RCSP-DJ), or maintain a fixed priority so that the highest priority flows must contend without regard to past frame arrival treatment (i.e. RCSP-RJ). In this dissertation the FlexTDMA protocol is defined which supports closed network communication. FlexTDMA will be enhanced to accommodate real-world networking conditions (FlexTDMA+) and will be enhanced to support simultaneous multicast (FlexTDMA++). The FlexTDMA scheduling algorithm delivers frame data on each flow nearly at the maximal delay bound with minimal delay-jitter in an asynchronous network. Industrial control switching network systems will benefit from FlexTDMA when the complexity of system level synchronization is unacceptable, but the component switches must operate independently. FlexTDMA does not require synchronous network clock coordination and preserves the data content of frames. FlexTDMA+ includes three improvements: baseline preemption, partial baselining and baseline deadline density control, which are used to support real-world conditions of node periodic on-off transmission, clock drift, frame loss and bandwidth load. FlexTDMA++ supports simultaneous multicast under real-world conditions of switch failures, node periodic on-off transmission, clock drift, frame loss and bandwidth load

Compilation de systèmes temps réel

I introduce and advocate for the concept of Real-Time Systems Compilation. By analogy with classical compilation, real-time systems compilation consists in the fully automatic construction of running, correct-by-construction implementations from functional and non-functional specifications of embedded control systems. Like in a classical compiler, the whole process must be fast (thus enabling a trial-and-error design style) and produce reasonably efficient code. This requires the use of fast heuristics, and the use of fine-grain platform and application models. Unlike a classical compiler, a real-time systems compiler must take into account non-functional properties of a system and ensure the respect of non-functional requirements (in addition to functional correctness). I also present Lopht, a real-time systems compiler for statically-scheduled real-time systems we built by combining techniques and concepts from real-time scheduling, compilation, and synchronous languages

Sovereignty Through Security? Canada's Arctic Defence in the Surveillance Age

This project considers how materials, practices and semiotics align and structure the development and use of security technologies in the Canadian Arctic. The dissertation asks: does the development of new technologies geared towards surveillance of the Canadian Arctic represent a new approach to security in the North? It is argued that current technological developments are grounded in a particular sociotechnical imaginary that is at once predicated on historical state practices while drawing from a more comprehensive assemblage of modern state strategies that are refracted through a lens of futurity. Notably, how the Arctic is understood and rationalized as a space of social and political life is dependent on a uniquely securitized image of the future. Within this imaginary, the Canadian state's rhetorical claims to sovereignty are threatened by the potential for competing expressions of power enabled by climate change, technological diffusion, and other trends at the international scale. Consequently, technologies developed for surveillance, intelligence, and Arctic security more broadly are designed to support practices of pre-emption as techniques of state power. Canada is prioritizing technological innovation as a governance strategy designed to rationalize and consolidate its power over its Arctic territory. Broadly, this strategy is predicated on illuminating the Arctic using the visible and non-visible spectrums, which contributes to sovereignty as a rhetorical, material, and symbolic signifier of state power and control. In order to demonstrate the interplay between this imaginary and material expressions of state sovereignty, the concept of full-spectral dominance is deployed as a technique of power that captures the state's security ambitions through the joint practices of surveillance and intelligence (sensing). This concept is illustrated through an examination of current technological developments being pursued by the Canadian state through the All Domain Situational Awareness (ADSA) Program led by National Defence along with related programs and developments. In sum, these developments exhibit how increasingly imaginative views of the Arctic’s future contour state-led practices in the present

Prognostics and health management of power electronics

Prognostics and health management (PHM) is a major tool enabling systems to evaluate their reliability in real-time operation. Despite ground-breaking advances in most engineering and scientific disciplines during the past decades, reliability engineering has not seen significant breakthroughs or noticeable advances. Therefore, self-awareness of the embedded system is also often required in the sense that the system should be able to assess its own health state and failure records, and those of its main components, and take action appropriately. This thesis presents a radically new prognostics approach to reliable system design that will revolutionise complex power electronic systems with robust prognostics capability enhanced Insulated Gate Bipolar Transistors (IGBT) in applications where reliability is significantly challenging and critical. The IGBT is considered as one of the components that is mainly damaged in converters and experiences a number of failure mechanisms, such as bond wire lift off, die attached solder crack, loose gate control voltage, etc. The resulting effects mentioned are complex. For instance, solder crack growth results in increasing the IGBT’s thermal junction which becomes a source of heat turns to wire bond lift off. As a result, the indication of this failure can be seen often in increasing on-state resistance relating to the voltage drop between on-state collector-emitter. On the other hand, hot carrier injection is increased due to electrical stress. Additionally, IGBTs are components that mainly work under high stress, temperature and power consumptions due to the higher range of load that these devices need to switch. This accelerates the degradation mechanism in the power switches in discrete fashion till reaches failure state which fail after several hundred cycles. To this end, exploiting failure mechanism knowledge of IGBTs and identifying failure parameter indication are background information of developing failure model and prognostics algorithm to calculate remaining useful life (RUL) along with ±10% confidence bounds. A number of various prognostics models have been developed for forecasting time to failure of IGBTs and the performance of the presented estimation models has been evaluated based on two different evaluation metrics. The results show significant improvement in health monitoring capability for power switches.Furthermore, the reliability of the power switch was calculated and conducted to fully describe health state of the converter and reconfigure the control parameter using adaptive algorithm under degradation and load mission limitation. As a result, the life expectancy of devices has been increased. These all allow condition-monitoring facilities to minimise stress levels and predict future failure which greatly reduces the likelihood of power switch failures in the first place

Emerging risks identification on food and feed - EFSA

The European Food Safety Authority's has established procedures for the identification of emerging risk in food and feed. The main objectives are to: (i) to carry out activities aiming at identifying, assessing and disseminating information on emerging issues and ensure coordination with relevant networks and international organisations; (ii) promote the identification of data sources and data collection and /or data generation in prioritised emerging issues; and the (iii) evaluate of the collected information and identify of emerging risks. The objective(s) of the Standing Working Group on Emerging Risks (SWG‐ER) is to collaborate with EFSA on the emerging risks identification (ERI) procedure and provide strategic direction for EFSA work building on past and ongoing projects related to EFSA ERI procedure. The SWG‐ER considered the ERI methodologies in place and results obtained by EFSA. It was concluded that a systematic approach to the identification of emerging issues based on experts’ networks is the major strength of the procedure but at present, it is mainly focused on single issues, over short to medium time horizons, no consistent weighting or ranking is applied and clear governance of emerging risks with follow‐up actions is missing. The analysis highlighted weaknesses with respect to data collection, analysis and integration. No methodology is in place to estimate the value of the procedure outputs in terms of avoided risk and there is urgent need for a communication strategy that addresses the lack of data and knowledge uncertainty and addresses risk perception issues. Recommendations were given in three areas: (i) Further develop a food system‐based approach including the integration of social sciences to improve understanding of interactions and dynamics between actors and drivers and the development of horizon scanning protocols; (ii) Improve data processing pipelines to prepare big data analytics, implement a data validation system and develop data sharing agreements to explore mutual benefits; and (iii) Revise the EFSA procedure for emerging risk identification to increase transparency and improve communication