One way to tackle the climate change society is facing today is through the change to renewable energy sources, such as wind power. Today, a trend when it comes to technology is that products are evolving into becoming more cyber-physical systems (CPS) by integrating functions realized with mechanics, control and communication. One challenge for CPS is to find cost-effective and reliable sensor solutions.  The purpose of this project is to lay the foundations for an intelligent CPS with the help of sensors and condition monitoring methods that, with further development, can reduce the downtime of a wind turbine. Thus, the reliability of the wind turbine and the profitability of its investors increase. The aim of the work is to develop an overall concept for a sensor package with analysis methods that enable real-time diagnosis in the gearbox of a wind turbine. This sensor package should be able to monitor the most common problems that arise in the gearbox and it should also be able to be used as a basis for a possible development of a CPS in the future.  The work is based on an information search that enables the creation of a list of requirements. This then forms the basis for concept generation through the use of a function/means tree and concept evaluation through the use of elimination matrix, weight determination matrix and weighted criteria matrix.  The work concludes that there are four main types of failures that occur in the gearbox and that should be monitored. These are scuffing, micropitting, propagation of cracks and bearing failure. The final concept uses vibration analysis for monitoring of micropitting, crack propagation and bearing failure, oil analysis for monitoring of scuffing and micropitting and temperature measurement for monitoring of scuffing and bearing failure. For vibration analysis, piezoelectric sensors are used, for oil analysis electromagnetic sensors and for temperature measurement resistance thermometers are used.  The work finds that it is appropriate in this day and age to use well-established methods for condition monitoring in the gearbox of wind turbines. / Ett sätt att tackla de klimatförändringar samhället står inför idag är genom omställningen till förnybara energikällor, såsom vindkraft. Idag är en trend när det kommer till teknik att produkter utvecklas till att allt mer bli cyberfysiska system (CPS) genom att de integrerar funktioner som realiseras med mekanik, reglering och kommunikation. En utmaning för CPS är att hitta kostnadseffektiva och tillförlitliga sensorlösningar.  Syftet med detta projekt är att lägga grunden till ett intelligent CPS med hjälp av sensorer och tillståndsövervakningsmetoder som med vidare utveckling ska kunna minska stilleståndstiden hos ett vindkraftverk. Således ökar tillförlitligheten hos vindkraftverket samt räntabiliteten för investerarna av dessa. Arbetets mål är att utveckla ett övergripande koncept för ett sensorpaket med analysmetoder som möjliggör realtidsdiagnos i växellådan hos ett vindkraftverk. Detta sensorpaket ska kunna övervaka de vanligaste problemen som uppstår i växellådan och ska kunna användas som grund för eventuell utveckling av ett CPS i framtiden.  Arbetet grundas i en informationssökning som möjliggör skapandet av en kravspecifikation. Denna ligger sedan till grund för konceptgenerering genom användandet av funktions/medelträd samt konceptutvärdering genom användandet av elimineringsmatris, viktbestämningsmatris samt kriterieviktsmetoden.  I arbetet framkommer att det finns fyra huvudsakliga skador som uppkommer i växellådan och som bör övervakas. Dessa är scuffing, mikropitting, sprickpropagering och lagerhaveri. Det slutgiltiga konceptet använder vibrationsanalys för övervakning av mikropitting, sprickpropagering och lagerhaveri, oljeanalys för övervakning av scuffing och mikropitting samt temperaturmätning för övervakning av scuffing och lagerhaveri. Vid vibrationsanalys används piezoelektriska sensorer, vid oljeanalys elektromagnetiska sensorer och för temperaturmätning resistanstermometrar.  Arbetet konstaterar att det i dagsläget är lämpligt att använda väletablerade metoder för tillståndsövervakning i växellådan hos vindkraftverk.

<p>Precision livestock farming (PLF) has emerged as a solution to address global challenges related to food scarcity, increasing demand for animal products, slim profit margins in livestock production, and growing societal concerns regarding farm animal welfare. By offering individualized care for animals, PLF aims to provide labor savings, enhanced monitoring, and improved control capabilities within complex farming systems, enabled by digital technologies. The adoption of an individual-centric approach to farming through PLF is anticipated to enhance farm productivity and ensure ethical treatment of animals while mitigating concerns associated with labor shortages in modern intensive farming operations. Real-time continuous monitoring of each animal enables precise and accurate health and well-being management. However, to achieve these benefits, large-scale animal farms require commercially viable technological solutions for individualized care and welfare. Cyber-physical systems (CPSs) offer precise monitoring and control and present a promising avenue for PLF but pose significant implementation challenges.</p> <p>  In this work, a generalizable CPS architecture was formalized with active robotic nodes that can realize adaptive continuous real-time animal health monitoring to maximize productivity, animal welfare, and sustainability. Taking the example of dairy farming, a resource- and criticality-aware CPS was developed that enables real-time resource-aware sensing, adaptive control, and agile networking with an emphasis on handling emergencies autonomously. Using a decentralized approach, each node was made capable of optimizing its operation to be resource conscious, while also being able to identify emergency conditions in real-time. In this novel design, we accommodate the social dynamics of the herd and effectively address the various types of emergencies possible in PLF. Moreover, the communication was customized for the unique needs of animal agriculture, wherein it reduced latency and power consumption while ensuring collision-free two-way synchronization with adaptive range extension for emergency conditions. Further, since the CPS was centered around animals, a special robust security layer was also developed and implemented to protect the active embodied nodes against known and unknown malicious attacks. The proposed CPS reference architecture provides a foundation for implementing individualized care and welfare, ultimately improving the efficiency and sustainability of livestock operations.</p>

No description available.

In today's modern world, Cyber-Physical Systems (CPS) have gained widespread prevalence, offering tremendous benefits while also increasing society's dependence on them. Given the direct interaction of CPS with the physical environment, their malfunction or compromise can pose significant risks to human life, property, and the environment. However, as the complexity of CPS rises due to heightened expectations and expanded functional requirements, ensuring their trustworthy operation solely during the development process becomes increasingly challenging. This thesis introduces and delves into the novel concept of the 'Protective Shell' – a real-time safeguard actively monitoring CPS during their operational phases. The protective shell serves as a last line of defence, designed to detect abnormal behaviour, conduct thorough analyses, and initiate countermeasures promptly, thereby mitigating unforeseen risks in real-time. The primary objective of this research is to enhance the overall safety and security of CPS by refining, partly implementing, and evaluating the innovative protective shell concept. To provide context for collaborative systems working towards higher objectives — common within CPS as system-of-systems (SoS) — the thesis introduces the 'Emergence Matrix'. This matrix categorises outcomes of such collaboration into four quadrants based on their anticipated nature and desirability. Particularly concerning are outcomes that are both unexpected and undesirable, which frequently serve as the root cause of safety accidents and security incidents in CPS scenarios. The protective shell plays a critical role in mitigating these unfavourable outcomes, as conventional vulnerability elimination procedures during the CPS design phase prove insufficient due to their inability to proactively anticipate and address these unforeseen situations. Employing the design science research methodology, the thesis is structured around its iterative cycles and the research questions imposed, offering a systematic exploration of the topic. A detailed analysis of various safety accidents and security incidents involving CPS was conducted to retrieve vulnerabilities that led to dangerous outcomes. By developing specific protective shells for each affected CPS and assessing their effectiveness during these hazardous scenarios, a generic core for the protective shell concept could be retrieved, indicating general characteristics and its overall applicability. Furthermore, the research presents a generic protective shell architecture, integrating advanced anomaly detection techniques rooted in explainable artificial intelligence (XAI) and human machine teaming. While the implementation of protective shells demonstrate substantial positive impacts in ensuring CPS safety and security, the thesis also articulates potential risks associated with their deployment that require careful consideration. In conclusion, this thesis makes a significant contribution towards the safer and more secure integration of complex CPS into daily routines, critical infrastructures and other sectors by leveraging the capabilities of the generic protective shell framework.:1 Introduction 1.1 Background and Context 1.2 Research Problem 1.3 Purpose and Objectives 1.3.1 Thesis Vision 1.3.2 Thesis Mission 1.4 Thesis Outline and Structure 2 Design Science Research Methodology 2.1 Relevance-, Rigor- and Design Cycle 2.2 Research Questions 3 Cyber-Physical Systems 3.1 Explanation 3.2 Safety- and Security-Critical Aspects 3.3 Risk 3.3.1 Quantitative Risk Assessment 3.3.2 Qualitative Risk Assessment 3.3.3 Risk Reduction Mechanisms 3.3.4 Acceptable Residual Risk 3.4 Engineering Principles 3.4.1 Safety Principles 3.4.2 Security Principles 3.5 Cyber-Physical System of Systems (CPSoS) 3.5.1 Emergence 4 Protective Shell 4.1 Explanation 4.2 System Architecture 4.3 Run-Time Monitoring 4.4 Definition 4.5 Expectations / Goals 5 Specific Protective Shells 5.1 Boeing 737 Max MCAS 5.1.1 Introduction 5.1.2 Vulnerabilities within CPS 5.1.3 Specific Protective Shell Mitigation Mechanisms 5.1.4 Protective Shell Evaluation 5.2 Therac-25 5.2.1 Introduction 5.2.2 Vulnerabilities within CPS 5.2.3 Specific Protective Shell Mitigation Mechanisms 5.2.4 Protective Shell Evaluation 5.3 Stuxnet 5.3.1 Introduction 5.3.2 Exploited Vulnerabilities 5.3.3 Specific Protective Shell Mitigation Mechanisms 5.3.4 Protective Shell Evaluation 5.4 Toyota 'Unintended Acceleration' ETCS 5.4.1 Introduction 5.4.2 Vulnerabilities within CPS 5.4.3 Specific Protective Shell Mitigation Mechanisms 5.4.4 Protective Shell Evaluation 5.5 Jeep Cherokee Hack 5.5.1 Introduction 5.5.2 Vulnerabilities within CPS 5.5.3 Specific Protective Shell Mitigation Mechanisms 5.5.4 Protective Shell Evaluation 5.6 Ukrainian Power Grid Cyber-Attack 5.6.1 Introduction 5.6.2 Vulnerabilities in the critical Infrastructure 5.6.3 Specific Protective Shell Mitigation Mechanisms 5.6.4 Protective Shell Evaluation 5.7 Airbus A400M FADEC 5.7.1 Introduction 5.7.2 Vulnerabilities within CPS 5.7.3 Specific Protective Shell Mitigation Mechanisms 5.7.4 Protective Shell Evaluation 5.8 Similarities between Specific Protective Shells 5.8.1 Mitigation Mechanisms Categories 5.8.2 Explanation 5.8.3 Conclusion 6 AI 6.1 Explainable AI (XAI) for Anomaly Detection 6.1.1 Anomaly Detection 6.1.2 Explainable Artificial Intelligence 6.2 Intrinsic Explainable ML Models 6.2.1 Linear Regression 6.2.2 Decision Trees 6.2.3 K-Nearest Neighbours 6.3 Example Use Case - Predictive Maintenance 7 Generic Protective Shell 7.1 Architecture 7.1.1 MAPE-K 7.1.2 Human Machine Teaming 7.1.3 Protective Shell Plugin Catalogue 7.1.4 Architecture and Design Principles 7.1.5 Conclusion Architecture 7.2 Implementation Details 7.3 Evaluation 7.3.1 Additional Vulnerabilities introduced by the Protective Shell 7.3.2 Summary 8 Conclusion 8.1 Summary 8.2 Research Questions Evaluation 8.3 Contribution 8.4 Future Work 8.5 Recommendation

No description available.

Linear repetitive projects, which are resource-driven in nature, are characterized by a series of repetitive activities in which the resources share the same space either in sequential or parallel manner. The frequent movement of resources over limited shared space needs to be well-planned to avoid potential issues during the execution of linear projects. As such, schedules developed for these projects needs not only to take into account all the logical, project-dependent and precedence constraints of activities but also to incorporate the space and time constraints that co-exist for the movement of thei8r resources. Negligence in incorporating spatial and temporal constraints in developing and improving schedules of linear projects increases the risk of delays and workspace congestions that can substantially hinder the performance of the activity resources. The study presented here proposes and develops an uncertainty-aware scheduling and control framework for linear projects to address the needs mentioned above. For this purpose, first, a new type of float was introduced as the Space-Time Float. The Space-Time Float is an envelope for all possible movement patterns that a linear activity or its associated resources can take considering the time and space constraints of that activity. The next endeavor in the development of the uncertainty-aware linear scheduling and control framework was to augment the current linear scheduling methods by presenting an uncertainty-aware optimization method to optimize the duration of linear projects while minimizing their potential congestions. A constraint satisfaction approach was used for the two-tier optimization of duration and congestion, and a fuzzy inference system was incorporated to assess the inherent uncertainty in linear activities. A new type of buffer, Uncertainty-Aware Productivity Buffer is also introduced to account for the uncertainties inherent in project activities. Spatial progress of activities needs not only to be considered in the planning phase but also to be closely monitored during construction. The framework presented in this study also applies to the monitoring and control of linear projects. While most of the current methods still do not accommodate real-time bi-directional control of linear projects, this framework is based on the Cyber-Physical Systems (CPS) architecture and bi-directional communication of data. To this end, a CPS-based application for Earned Value (EV) monitoring and control of road and highway projects is presented. Different steps of the generated framework are validated through various literature and field-based case studies. The results demonstrate the effectiveness of the presented method in planning and control of unforeseen variations from the planned schedules of linear projects. As such, the present study contributes and adds to the current body of knowledge of linear projects by presenting an efficient scheduling and control framework that takes into account logical, spatio-temporal and project-based constraints of linear activities. / Thesis / Doctor of Philosophy (PhD)

The original FlexiChain and its descendants are a revolutionary distributed ledger technology (DLT) for cyber-physical systems (CPS) and their embedded systems (ES). FlexiChain, a DLT implementation, uses cryptography, distributed ledgers, peer-to-peer communications, scalable networks, and consensus. FlexiChain facilitates data structure agreements. This thesis offers a Block Directed Acyclic Graph (BDAG) architecture to link blocks to their forerunners to speed up validation. These data blocks are securely linked. This dissertation introduces Proof of Rapid Authentication, a novel consensus algorithm. This innovative method uses a distributed file to safely store a unique identifier (UID) based on node attributes to verify two blocks faster. This study also addresses CPS hardware security. A system of interconnected, user-unique identifiers allows each block's history to be monitored. This maintains each transaction and the validators who checked the block to ensure trustworthiness and honesty. We constructed a digital version that stays in sync with the distributed ledger as all nodes are linked by a NodeChain. The ledger is distributed without compromising node autonomy. Moreover, FlexiChain Layer 0 distributed ledger is also introduced and can connect and validate Layer 1 blockchains. This project produced a DAG-based blockchain integration platform with hardware security. The results illustrate a practical technique for creating a system depending on diverse applications' needs. This research's design and execution showed faster authentication, less cost, less complexity, greater scalability, higher interoperability, and reduced power consumption.

<p dir="ltr">The world is increasingly dependent on cyber-physical systems (CPSs), e.g., robotic vehicles (RVs) and industrial control systems (ICSs). CPSs operate autonomously by processing data coming from both “cyberspace”—such as user commands—and “physical space”—such as sensors that measure the physical environment in which they operate. However, even after decades of research, CPSs remain susceptible to threats from attackers, primarily due to the increased complexity created by interaction with cyber and physical space (e.g., the cascading effects that changes in one space can impact on the other). In particular, the complexity causes two primary threats that increase the risk of causing physical damage to RVs: (1) logic bugs causing undesired physical behavior from the developers expectations; and (2) physical sensor attacks—such as GPS or acoustic noise spoofing—that disturb an RV’s sensor readings. Dealing with these threats requires addressing the interplay between cyber and physical space. In this dissertation, we systematically analyze the interplay between cyber and physical space, thereby tackling security problems created by such complexity. We present novel algorithms to detect logic bugs (PGFuzz in Chapter 2), help developers fix them (PGPatch in Chapter 3), and test the correctness of the patches attempting to address them (PatchVerif in Chapter 4). Further, we explain algorithms to discover the root causes and formulate countermeasures against physical sensor attacks that target RVs in Chapter 5.</p>

Background: The manufacturing industry is diverting away from the one-size-fits-all mass manufacture towards more customized processes. With increasingly individualized consumer preferences and an intense competitive environment, food manufacturers are required to meet specific consumer demands with similar efficiency to those produced massively. Such market requirements are feasible with the technological advancements envisioned by Industry 4.0. The consequences of such are increased flexibility and mass customization in manufacturing which forces the food manufacturer towards its realization. The integration process, however, involves a comprehensive transformation that affects every aspect of the organization. This consequently imposes significant challenges upon the food manufacturing company. Purpose: The study aims to investigate the transformation process ensued by the food manufacturer for Industry 4.0. Consequently, a conceptual framework is developed detailing the application of Industry 4.0 in the food manufacturing industry. Method: An inductive qualitative approach, in combination with a multiple-case study, is pursued to address the formulated questions of research. Based on such, semi-structured interviews were conducted with individuals representing three multinational food manufacturers. Further, a thematic analytical technique was adopted as means to identify similarities and patterns within the obtained data. The collected data was analyzed using thematic analysis through which the researchers came up with the conceptual framework. Conclusion: The results of the research reveal internal and external factors such as labor policies and IT infrastructure to influence the transformation process for Industry 4.0. In due to this, the implementation of the phenomenon occurs phase-wise, globally coordinated and regionally concentrated. This enables the organization to overcome the obstacles faced and, subsequently, ensure the successful deployment of Industry 4.0.

Global navigation satellite systems (GNSS) have radically changed business, industry, and society, shaping the way we transport, navigate, and generally live every day. After all these years, however, GNSS location information remains only valuable outdoors, leaving indoor environments where people dwell most of the time without proper localization support. Many technologies and systems have approached this problem including optical, inertial, ultrasonic, and radio-frequency (RF), to name a few; yet the problem remains. In this thesis, inspired by the indisputable success of GNSS and the re-emergence of ultra-wideband (UWB) radios to the forefront of technology, we aim to change the state of affairs in RF localization by proposing novel clean-slate UWB ranging and localization schemes based on concurrent transmissions. These are generally considered harmful for communication but become a rich source of localization information when combined with knowledge of the channel impulse response (CIR). Our first novel contribution lies in the concept of concurrent ranging, which allows mobile nodes to simultaneously measure the distance to multiple devices—hereafter, called responders—removing the need for the wasteful long packet exchanges traditionally used for ranging and localization. Different from conventional schemes, which spread responder transmissions over time, we force responders to transmit concurrently and let their signals “fuse” in the wireless channel; the resulting impulse response, as measured by commercial UWB radios, contains all the necessary timing information to extract the desired distance to all responders. This first contribution, however, also serves us to realize the many challenges ahead to unlock the real power of concurrent transmissions for localization. We address these challenges along the way, starting with Chorus, our second contribution. Chorus exploits an anchor infrastructure that transmits packets concurrently. Mobile nodes listen for these transmissions and measure from the CIR the time difference of arrival (TDoA) of the concurrent signals, privately computing their own position at a high rate using hyperbolic localization. This reverse TDoA scheme, although simple in concept, is extremely powerful in that it enables passive self-localization of infinitely many targets at once, a feature largely missing in the RF literature. In Chorus, we address the difficult challenges to reliably detect and identify the signal from the different responders. Yet, the limited transmission precision of commercial UWB transceivers constrains the many benefits of Chorus. In this context, we i) contribute a model to ascertain the impact of the transmission uncertainty on concurrent transmissions, and ii) address the issue with a compensation mechanism that fine-tunes the local oscillator frequency of responders while they prepare to transmit, allowing us to simultaneously tackle the impact of clock drift on distance estimation. We demonstrate in our evaluation that with this compensation mechanism we can schedule transmissions with &lt; 1 ns error, removing the need to share timestamps to precisely measure distance. We rebuild concurrent ranging around this mechanism, obtaining decimeter-level ranging and localization at a fraction of the cost of conventional schemes. These results turn concurrent ranging into an immediately applicable technique that new systems can now exploit, benefiting from a different set of trade-offs hitherto unavailable. Further, the TX compensation mechanism can be directly applied to Chorus, similarly making fast and accurate passive self-localization a tangible reality. We continue our endeavor with a systematic characterization of the conditions under which UWB concurrent transmissions succeed to provide reliable ranging and communication across different complex channels. The results we put forth empower developers to fully exploit concurrent transmissions in their designs, potentially inspiring a new wave of ranging, and also communication, primitives that can bring to UWB the same striking benefits found in low-power narrowband radios. The thesis is completed by looking at other challenges preventing the wide adoption of UWB localization systems, namely, large-scale operation, energy efficiency, and the complexity to install anchor deployments. We tackle these aspects in the last part of the thesis with three additional contributions. First, we propose Talla, a TDoA system that provides seamless large-scale localization for many tags across cells of time-synchronized anchors. Secondly, we fuse UWB ranging with odometry information and build an uncertainty model that only triggers new UWB estimates if and when needed, reducing consumption and channel utilization while satisfying the application-specific demands in terms of accuracy. And thirdly, we build state-of-the-art mechanisms to automatically compute the positions of all anchors deployed across large areas based on ranging information, facilitating anchor network deployment for the many UWB-based real-time location systems (RTLS) to come. Overall, this thesis changes the landscape of UWB localization with a new set of potentially disruptive schemes and systems that exploit the peculiar benefits of concurrent transmissions and that consequently redefine the trade-offs of the technology.