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.

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<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>

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The advent of Information and Communications Technology (ICT) in power systems has revolutionized the monitoring, operation, and control mechanisms through advanced control and communication functions. However, this integration significantly elevates the vulnerability of modern power systems to cyber intrusions, posing severe risks to the integrity and reliability of the power grid. This dissertation presents the results of a comprehensive study into the detection of cyber intrusions and restoration of cyber-power systems post-attack with a focus on IEC 61850 based substations and recovery methodologies in the cyber-physical system framework. The first step of this study is to develop a novel Intrusion Detection System (IDS) specifically designed for deployment in automated substations. The proposed IDS effectively identifies falsified measurements within Manufacturing Messaging Specification (MMS) messages by verifying the consistency of electric circuit laws. This distributed approach helps avoid the transfer of contaminated measurements from substations to the control center, ensuring the integrity of SCADA systems. Utilizing a cyber-physical system testbed and the IEEE 39-bus test system, the IDS demonstrates high detection accuracy and validates its efficacy in real-time operational environments. Building upon the intrusion detection methodology, this dissertation advances into cyber system recovery strategies, which are designed to meet the challenges of restoring a power grid as a cyber-physical system following catastrophic cyberattacks. A novel restoration strategy is proposed, emphasizing the self-recovery of a substation automation system (SAS) within the substation through dynamic network reconfiguration and collaborative efforts among Intelligent Electronic Devices (IEDs). This strategy, validated through a cyber-power system testbed incorporating SDN technology and IEC 61850 protocol, highlights the critical role of cyber recovery in maintaining grid resilience. Further, this research extends its methodology to include a cyber-physical system restoration strategy that integrates an optimization-based multi-system restoration approach with cyber-power system simulation for constraint checking. This innovative strategy developed and validated using an Software Defined Networking (SDN) network for the IEEE 39-bus system, demonstrates the capability to efficiently restore the cyber-power system and maximize restoration capability following a large-scale cyberattack. Overall, this dissertation makes original contributions to the field of power system security by developing and validating effective mechanisms for the detection of and recovery from cyber intrusions in the cyber-power system. Here are the main contributions of this dissertation: 1) This work develops a distributed IDS, specifically designed for the substation automation environment, capable of pinpointing the targets of cyberattacks, including sophisticated attacks involving multiple substations. The effectiveness of this IDS in a real-time operational context is validated to demonstrate its efficiency and potential for widespread deployment. 2) A novel recovery strategy is proposed to restore the critical functions of substations following cyberattacks. This strategy emphasizes local recovery procedures that leverage the collaboration of devices within the substation network, circumventing the need for external control during the initial recovery phase. The implementation and validation of this method through a cyber-physical system testbed—specifically, within an IEC 61850 based Substation Automation System (SAS)—underscores its practicality and effectiveness in real-world scenarios. 3) The dissertation results in a new co-restoration strategy that integrates mixed integer linear programming to sequentially optimize the restoration of generators, power components, and communication nodes. This approach ensures optimal restoration decisions within a limited time horizon, enhancing the recovery capabilities of the cyber-power system. The application of an SDN based network simulator facilitates accurate modeling of cyber-power system interactions, including communication constraints and dynamic restoration scenarios. The strategy's adaptability is further improved by real-time assessment of the feasibility of the restoration sequence incorporating power flow and communication network constraints to ensure an effective recovery process. / Doctor of Philosophy / Electricity is a critical service that supports the society and economy. Today, electric power systems are becoming smarter, using advanced Information and Communications Technology to manage and distribute electricity more efficiently. This new technology creates a smart grid, a network that not only delivers power but also uses computers and other tools to remotely monitor electricity flows and address any issues that may arise. However, these smart systems with high connectivity utilizing information and communication systems can be vulnerable to cyberattacks, which could disrupt the electricity supply. To protect against these threats, this study is focused on creating systems that can detect when an abnormal condition is taking place in the cyber-power grid. These detection systems are designed to detect and identify signs of cyberattacks at key points in the power network, particularly at substations, which play a vital role in the delivery of electricity. Substations control the power grid operating conditions to make sure that electricity service is reliable and efficient for the consumers Just like traffic lights help manage the flow of vehicles, substations manage the flow of electricity to make sure electric energy is delivered to where it needed. Once a cyberattack is detected, the next step is to stop the attack and mitigate the impact it may have made to ensure that the power grid returns to normal operations as quickly as possible. This dissertation is concerned with the development and validation of analytical and computational methods to quickly identify the cyberattacks and prevent the disruptions to the electricity service. Also, the focus of this work is also on a coordinated recovery of both the cyber system ( digital controls and monitoring) and power system (physical infrastructure including transformers and transmission and distribution lines). This co-restoration approach is key to sustain the critical electricity service and ensures that the grid is resilient against the cyber threats. By developing strategies that address both the cyber and physical aspects, the proposed methodology aims to minimize downtime and reduce the impact of large-scale cyberattacks on the electrical infrastructure. The impact of the results of this dissertation is the enhancement of security and resilience of the electric energy supply in an era where the risks of cyber threats are increasingly significantly. Overall, by developing new methodologies to detect and respond to cyberattacks, the cyber-power system's capability to withstand and recover from cyberattacks is enhanced in the increasingly technology-dependent power grid environment.

A Cyber-Physical System (CPS) is a large-scale, distributed, embedded system, consisting of various components that are glued together to realize control, computation and communication functions. Although these systems are complex, they are ubiquitous in the Internet of Things (IoT) era of autonomous vehicles/drones, smart homes, smart grids, etc. where everything is connected. These systems are vulnerable to unauthorized penetration due to the absence of proper security features and safeguards to protect important information. Examples such as the typewriter hack involving subversive chips resulting in leakage of keystroke data and hardware backdoors crippling anti-aircraft guns during an attack demonstrate the need to protect all system functions. With more focus on securing a system, trust in untrusted components at the integration stage is of a higher priority. This work builds on a red-black security system, where an architecture testbed is developed with critical and non-critical IP cores and subjected to a variety of Hardware Trojan Threats (HTTs). These attacks defeat the classic trusted hardware model assumptions and demonstrate the ability of Trojans to evade detection methods based on physical characteristics. A novel metric is defined for hardware Trojan detection, termed as HTT Detectability Metric (HDM) that leverages a weighted combination of normalized physical parameters. Security analysis results show that using HDM, 86% of the implemented Trojans were detected as compared to using power consumption, timing variation and resource utilization alone. This led to the formulation of the security requirements for the development of a novel, distributed and secure methodology for enhancing trust in systems developed under untrusted environments called FIDelity Enhancing Security (FIDES). FIDES employs a decentralized information flow control (DIFC) model that enables safe and distributed information flows between various elements of the system such as IP cores, physical memory and registers. The DIFC approach annotates/tags each data item with its sensitivity level and the identity of the participating entities during the communication. Trust enhanced FIDES (TE-FIDES) is proposed to address the vulnerabilities arising from the declassification process during communication between third-party soft IP cores. TE-FIDES employs a secure enclave approach for preserving the confidentiality of the sensitive information in the system. TE-FIDES is evaluated by targeting an IoT-based smart grid CPS application, where malicious third-party soft IP cores are prevented from causing a system blackout. The resulting hardware implementation using TE-FIDES is found to be resilient to multiple hardware Trojan attacks. / Ph. D. / The Internet-of-Things (IoT) has emerged as one of the most innovative multidisciplinary paradigms combining heterogeneous sensors, software architectures, embedded hardware systems, and data analytics. With the growth in deployment of IoT systems, security of the sensors and trustworthiness of the data exchanged is of paramount significance. IoT security approaches are derived from the vulnerabilities existing in cyber-physical systems (CPS) and the countermeasures designed against them. An unauthorized penetration due to the absence of safeguards can cripple the system and leak sensitive data. This dissertation studies the vulnerabilities posed due to the presence of hardware Trojans in such IoT-based CPS. FIDelity Enhancing Security (FIDES), named after the Greek Goddess of Trust, is a novel, distributed and secure methodology proposed to address the security requirements and enhance trust of systems developed in untrusted environments. FIDES utilizes a distributed scheme that monitors the communication between the Intellectual Property (IP) cores using tags. Trust Enhanced FIDES (TE-FIDES) is proposed to reduce the vulnerabilities arising from the declassification process of the third-party soft IP cores. TE-FIDES employs a secure enclave approach for preserving the integrity of the sensitive information in the system. In addition, TE-FIDES also uses a trust metric to record snapshots of each IP core’s state during the declassification process. TE-FIDES is evaluated by mapping an IoT-based CPS application and subjecting it to a variety of hardware Trojan attacks. The performance costs for resilient and trustworthy operation of the TE-FIDES implementation are evaluated and TE-FIDES proves to be resilient to the attacks with acceptable cyber costs.

O recente surgimento de um novo conceito que propõe a integração do mundo físico com sistemas computacionais leva as redes de sensores a serem unicamente parte de um processo colaborativo para fins de integração, com um objetivo maior do que só observar o ambiente. Este novo conceito é conhecido como Sistema Ciber-Físico (tradução do inglês Cyber Physical System - CPS), e consiste numa rede de elementos que atuam entre o meio físico e as aplicações computacionais (Sensoriamento - Atuação - Controle - Aplicação), concluindo num sistema de gestão capaz de agrupar diversas aplicações com capacidade de funcionamento autônomo, assim como distribuído. Entretanto, para que esta tecnologia se torne viável para os diversos contextos do mundo físico, é necessário considerar as limitações dos elementos computacionais que a integram e, para o caso, essas limitações passam a ser maiores quando se trata de uma rede de sensores. Este trabalho de tese tem foco na camada de sensoriamento, discute inicialmente alguns dos pressupostos supracitados e define algumas características e requisitos dos CPS necessárias para a padronização de alguns processos. Propõe também o desenvolvimento de uma Plataforma para redes de sensores em Sistemas Ciber-Físicos, um middleware, capaz de se adaptar às limitações e necessidades, que serão apresentadas posteriormente numa aplicação exemplo. Como primeiro ponto: i) O trabalho apresenta as necessidades para estes tipos de sistemas e aborda definições relevantes; ii) Discute-se a definição em camadas do middleware CiberSens iii) Aplicação da proposta numa aplicação-exemplo. Do primeiro ponto: Os CPS constituem uma pesquisa relativamente nova, como resultado, muitos aspectos precisam ser definidos com o intuito de facilitar o entendimento da arquitetura e implementçã. Do segundo ponto: Os dispositivos transdutores representam um papel de relevante importância nas diversas aplicações, na área de automação residencial e nas aplicações biomédicas, esta última com exponencial crescimento de aplicações que procuram melhorar a qualidade de vida dos pacientes. Nesse contexto, se faz necessário um minucioso estudo dos conceitos e características que dever~ao ser consideradas no desenho em camadas da plataforma de gerenciamento para redes de sensores em CPS. No desenho a flexibilidade do sistema dever´a estar sujeita ao fácil domínio e controle por parte de usuário final, que será o verdadeiro responsável pelo funcionamento do Sistema Ciber-Físico e da aplicação em curso. Do terceiro ponto: Com o intuito de eliminar possíveis erros e identificar limitações no uso do sistema por parte dos atores do sistema (usuário e administrador), além de demonstrar a viabilidade da proposta, é levado o modelamento e definição de conceitos para sua aplicação num caso real. Nesta etapa é realizada simultaneamente a implementação de um módulo integrador encarregado da captura e abstração de protocolos na camada de comunicação e conexão com o módulo de armazenamento, e a camada de serviços. Uma avaliação é necessária não só para validar a técnica e o modelo utilizado na implementação da arquitetura do CiberSens e sim também para determinar a confiabilidade da comunicação e eficácia ante um evento critico, a validação acontece através da formalização de processos de controle, sensoriamento e atuação com a ferramenta SysML. / Recently, the emergence of a new concept that proposes the integration of the physical world with computing systems, is taking sensor networks to be only part of a collaborative process with a larger goal than just observing the environment. This new paradigm is known as Cyber-Physical Systems, and consists of a network of elements that act between the physical environment and computational applications (Sensing - Actuation - Control - Application), ending in a management system able to group several applications with standalone and distributed operation capabilities. However, to this technology become viable for the diverse contexts of the physical world, it is necessary to consider the limitations of computational elements that compose it, and in this case, these limitations increase when it comes to sensor networks. This thesis focuses on the sensing layer, discusses some of the assumptions aforementioned and defines some characteristics and requirements of the CPS necessary to standardize some processes. It also proposes the development of a platform for sensor networks on Cyber-Physical Systems, a service-oriented middleware capable of adapting the limitations and needs presented later in a use case. As first item: i) The document presents the requirements for these types of systems and approaches relevant definitions. Secondly: ii) It is discussed the layered definition of the CiberSens service-oriented middleware. And third: iii) It is presented the proposal implementation in application-example. From the first item: The CPS are a relatively new field of research, as a result, many aspects need to be defined in order to simplify the understanding of the architecture and implementation. From the second item: The transducer devices have a relevant role on diverse applications used on the fields of home automation and in biomedical applications, the latter with an exponential growth of applications that try to improve the quality of life of patients. In this context, it is necessary a detailed study of the concepts and characteristics that should be considered during the layered design of the management platform for sensor networks in CPS. In the design, the system flexibility should be subject to an easy control and domain by the end user, who will be responsible for the actual functioning of the Cyber-Physical System and the ongoing application. From the third item: In order to eliminate possible errors, identify limitations in the system use by the system actors (user and administrator), and demonstrate the feasibility of the proposal, the modeling and concepts definition are applied in a real case. On this step is performed simultaneously an efficiency evaluation of the protocols capture and abstraction methods in the communication layer, the storage modulus, and the services layer. The evaluation is needed not only to validate the technique and the model used in the CiberSens architecture implementation, but also to determine the reliability the of communication and the effectiveness facing a critical event, validation occurs through the control process formalization, sensing and actuation, with SysML tool.

O recente surgimento de um novo conceito que propõe a integração do mundo físico com sistemas computacionais leva as redes de sensores a serem unicamente parte de um processo colaborativo para fins de integração, com um objetivo maior do que só observar o ambiente. Este novo conceito é conhecido como Sistema Ciber-Físico (tradução do inglês Cyber Physical System - CPS), e consiste numa rede de elementos que atuam entre o meio físico e as aplicações computacionais (Sensoriamento - Atuação - Controle - Aplicação), concluindo num sistema de gestão capaz de agrupar diversas aplicações com capacidade de funcionamento autônomo, assim como distribuído. Entretanto, para que esta tecnologia se torne viável para os diversos contextos do mundo físico, é necessário considerar as limitações dos elementos computacionais que a integram e, para o caso, essas limitações passam a ser maiores quando se trata de uma rede de sensores. Este trabalho de tese tem foco na camada de sensoriamento, discute inicialmente alguns dos pressupostos supracitados e define algumas características e requisitos dos CPS necessárias para a padronização de alguns processos. Propõe também o desenvolvimento de uma Plataforma para redes de sensores em Sistemas Ciber-Físicos, um middleware, capaz de se adaptar às limitações e necessidades, que serão apresentadas posteriormente numa aplicação exemplo. Como primeiro ponto: i) O trabalho apresenta as necessidades para estes tipos de sistemas e aborda definições relevantes; ii) Discute-se a definição em camadas do middleware CiberSens iii) Aplicação da proposta numa aplicação-exemplo. Do primeiro ponto: Os CPS constituem uma pesquisa relativamente nova, como resultado, muitos aspectos precisam ser definidos com o intuito de facilitar o entendimento da arquitetura e implementçã. Do segundo ponto: Os dispositivos transdutores representam um papel de relevante importância nas diversas aplicações, na área de automação residencial e nas aplicações biomédicas, esta última com exponencial crescimento de aplicações que procuram melhorar a qualidade de vida dos pacientes. Nesse contexto, se faz necessário um minucioso estudo dos conceitos e características que dever~ao ser consideradas no desenho em camadas da plataforma de gerenciamento para redes de sensores em CPS. No desenho a flexibilidade do sistema dever´a estar sujeita ao fácil domínio e controle por parte de usuário final, que será o verdadeiro responsável pelo funcionamento do Sistema Ciber-Físico e da aplicação em curso. Do terceiro ponto: Com o intuito de eliminar possíveis erros e identificar limitações no uso do sistema por parte dos atores do sistema (usuário e administrador), além de demonstrar a viabilidade da proposta, é levado o modelamento e definição de conceitos para sua aplicação num caso real. Nesta etapa é realizada simultaneamente a implementação de um módulo integrador encarregado da captura e abstração de protocolos na camada de comunicação e conexão com o módulo de armazenamento, e a camada de serviços. Uma avaliação é necessária não só para validar a técnica e o modelo utilizado na implementação da arquitetura do CiberSens e sim também para determinar a confiabilidade da comunicação e eficácia ante um evento critico, a validação acontece através da formalização de processos de controle, sensoriamento e atuação com a ferramenta SysML. / Recently, the emergence of a new concept that proposes the integration of the physical world with computing systems, is taking sensor networks to be only part of a collaborative process with a larger goal than just observing the environment. This new paradigm is known as Cyber-Physical Systems, and consists of a network of elements that act between the physical environment and computational applications (Sensing - Actuation - Control - Application), ending in a management system able to group several applications with standalone and distributed operation capabilities. However, to this technology become viable for the diverse contexts of the physical world, it is necessary to consider the limitations of computational elements that compose it, and in this case, these limitations increase when it comes to sensor networks. This thesis focuses on the sensing layer, discusses some of the assumptions aforementioned and defines some characteristics and requirements of the CPS necessary to standardize some processes. It also proposes the development of a platform for sensor networks on Cyber-Physical Systems, a service-oriented middleware capable of adapting the limitations and needs presented later in a use case. As first item: i) The document presents the requirements for these types of systems and approaches relevant definitions. Secondly: ii) It is discussed the layered definition of the CiberSens service-oriented middleware. And third: iii) It is presented the proposal implementation in application-example. From the first item: The CPS are a relatively new field of research, as a result, many aspects need to be defined in order to simplify the understanding of the architecture and implementation. From the second item: The transducer devices have a relevant role on diverse applications used on the fields of home automation and in biomedical applications, the latter with an exponential growth of applications that try to improve the quality of life of patients. In this context, it is necessary a detailed study of the concepts and characteristics that should be considered during the layered design of the management platform for sensor networks in CPS. In the design, the system flexibility should be subject to an easy control and domain by the end user, who will be responsible for the actual functioning of the Cyber-Physical System and the ongoing application. From the third item: In order to eliminate possible errors, identify limitations in the system use by the system actors (user and administrator), and demonstrate the feasibility of the proposal, the modeling and concepts definition are applied in a real case. On this step is performed simultaneously an efficiency evaluation of the protocols capture and abstraction methods in the communication layer, the storage modulus, and the services layer. The evaluation is needed not only to validate the technique and the model used in the CiberSens architecture implementation, but also to determine the reliability the of communication and the effectiveness facing a critical event, validation occurs through the control process formalization, sensing and actuation, with SysML tool.