Cyber-physical systems (CPS) integrate sensing, computing, communication and actuation capabilities to monitor and control operations in the physical environment. A key requirement of such systems is the need to provide predictable real-time performance: the timing correctness of the system should be analyzable at design time with a quantitative metric and guaranteed at runtime with high assurance. This requirement of predictability is particularly important for safety-critical domains such as automobiles, aerospace, defense, manufacturing and medical devices. The work in this dissertation focuses on the challenges arising from the use of modern multi-core platforms in CPS. Even as of today, multi-core platforms are rarely used in safety-critical applications primarily due to the temporal interference caused by contention on various resources shared among processor cores, such as caches, memory buses, and I/O devices. Such interference is hard to predict and can significantly increase task execution time, e.g., up to 12 commodity quad-core platforms. To address the problem of ensuring timing predictability on multi-core platforms, we develop novel analytical and systems techniques in this dissertation. Our proposed techniques theoretically bound temporal interference that tasks may suffer from when accessing shared resources. Our techniques also involve software primitives and algorithms for real-time operating systems and hypervisors, which significantly reduce the degree of the temporal interference. Specifically, we tackle the issues of cache and memory contention, locking and synchronization, interrupt handling, and access control for computational accelerators such as general-purpose graphics processing units (GPGPUs), all of which are crucial to achieving predictable real-time performance on a modern multi-core platform. Our solutions are readily applicable to commodity multi-core platforms, and can be used not only for developing new systems but also migrating existing applications from single-core to multi-core platforms.

Doctor of Philosophy / Department of Computing and Information Sciences / Gurdip Singh / In this dissertation, we propose a cyber-physical system model, and based on this model, present algorithms for a set of distributed computing problems. Our model specifies a cyber-physical system as a combination of cyber-infrastructure, physical-infrastructure, and user behavior specification. The cyber-infrastructure is superimposed on the physical-infrastructure and continuously monitors its (physical-infrastructure's) changing state. Users operate in the physical-infrastructure and interact with the cyber-infrastructure using hand-held devices and sensors; and their behavior is specified in terms of actions they can perform (e.g., move, observe). While in traditional distributed systems, users interact solely via the underlying cyber-infrastructure, users in a cyber-physical system may interact directly with one another, access sensor data directly, and perform actions asynchronously with respect to the underlying cyber-infrastructure. These additional types of interactions have an impact on how distributed algorithms for cyber-physical systems are designed. We augment distributed mutual exclusion and predicate detection algorithms so that they can accommodate user behavior, interactions among them and the physical-infrastructure. The new algorithms have two components - one describing the behavior of the users in the physical-infrastructure and the other describing the algorithms in the cyber-infrastructure. Each combination of users' behavior and an algorithm in the cyber-infrastructure yields a different cyber-physical system algorithm. We have performed extensive simulation study of our algorithms using OMNeT++ simulation engine and Uppaal model checker. We also propose Cyber-Physical System Modeling Language (CPSML) to specify cyber-physical systems, and a centralized global state recording algorithm.

La vérification à l'exécution est une technique prometteuse pour améliorer la sûreté des systèmes complexes. Ces systèmes peuvent être instrumentés afin qu'ils produisent des traces d'exécution permettant d'observer leur utilisation dans des conditions réelles. Un défi important est de fournir aux ingénieurs logiciel un langage formel simple adapté à l'expression des exigences les plus importantes. Dans cette thèse, nous nous intéressons à la vérification de dispositifs médicaux. Nous avons effectué l'analyse approfondie d'un dispositif médical utilisé mondialement afin d'identifier les exigences les plus importantes, ainsi que la nature précise des traces d'exécution qu'il produit. À partir de cette analyse, nous proposons ParTraP, un langage défini formellement et dédié à la spécification de propriétés sur des traces finies. Il a été conçu pour être accessible à des ingénieurs logiciels non qualifiés en méthodes formelles grâce à sa simplicité et son style déclaratif. Le langage étend les patrons de spécification initialement proposé par Dwyer et. al. avec des opérateurs paramétriques et temps-réel, des portées emboîtable, et des quantificateurs de premier ordre. Nous proposons également une technique de mesure de couverture pour ParTraP, et que le niveau de couverture d'une propriété temporelle permet de mieux la comprendre, ainsi que le jeu de traces sur lequel elle est évaluée. Finalement, nous décrivons l'implémentation d'un environnement de développement intégré pour ParTraP, qui est disponible sous une licence libre. / Runtime verification is a promising technique to improve the safety of complex systems. These systems can be instrumented to produce execution traces enabling us to observe their usage in the field. A significant challenge is to provide software engineers with a simple formal language adapted to the expression of their most important requirements. In this thesis, we focus on the verification of medical devices. We performed a thorough analysis of a worldwide-used medical device in order to identify those requirements, as well as the precise nature of its execution traces. In the light of this study, we propose ParTraP, a formally defined language dedicated to property specification for finite traces. It is designed to be accessible to software engineers with no training in formal methods thanks to its simplicity and declarative style. The language extends the specification patterns originally proposed by Dwyer et al. with parametrized constructs, nested scopes, real-time and first-order quantification. We also propose a coverage measurement technique for ParTraP, and we show that coverage information provides insights on a corpus of traces as well as a deeper understanding of temporal properties. Finally, we describe the implementation of an Integrated Development Environment for ParTraP, which is available under a free and open-source license.

Les systèmes industriels recouvrent de nombreuses formes. Aujourd'hui, ils sont le plus souvent organisés en réseaux. Les nouvelles technologies de l'information et de la communication apportent un ensemble de moyens supplémentaires pour réaliser des applications ayant un intérêt majeur pour renforcer l'exploitation sûre de ces systèmes et la sécurité des personnes.Parmi ces systèmes industriels, on peut citer les systèmes cyber-physiques (CPS) caractérisés par un grand nombre de variables, des non linéarités et des incertitudes. Leur décomposition en sous-systèmes, permet de les rendre plus facilement gérables et organisés de façon hiérarchique, est fondamentale. Chacun des sous-systèmes est constitué de différents composants remplaçables interconnectés qui réalisent différentes fonctions.Dans cette optique, nous proposons une approche de diagnostic basée sur quatre types de connaissances : fonctionnelle, structurelle, topologique et comportementale.Cette approche qui inclut la détection et la localisation, exploite la représentation des différentes connaissances pour détecter et isoler la source de défaillance. Afin de lever toute ambigüité de localisation, l’adjonction d’un automate temporisé permet, grâce à une analyse temporelle, d’identifier efficacement le ou les composants défectueux. L’approche multimodèle proposée est agencée autour de trois algorithmes.La modélisation et d’analyse des défaillances est illustrée sur un système cyber-physique : le robot de téléprésence "RobAIR". Les différents modèles de connaissances ont été établis avec une démarche d’analyse ainsi que la construction du diagnostiqueur basée sur des signatures préalablement définies.L‘implémentation des algorithmes de détection, d’isolation sous Simulink/ Stateflow de Matlab a permis de construire le diagnostiqueur selon la méthodologie proposée et valider ainsi notre approche par simulation du fonctionnement avec injection de façon aléatoire de différentes défaillances.La méthode d’analyse proposée a été appliquée aux tests de démarrage du robot RobAIR avec une attention particulière sur la partie déplacement. Le test de l’ensemble des fonctionnalités du robot est réalisé par la programmation de la carte Arduino. Pour cette application, les algorithmes de détection et d’isolation ont été complétés par la détection d’obstacle et l’identification du mode défaillance. / Industrial systems cover many forms. Today, they are most often organized in networks. The new information and communication technologies provide a set of additional means to realize applications of major interest to strengthen the safe operation of these systems and the safety of people.Among these industrial systems, we can cite cyber-physical systems (CPS) characterized by a large number of variables, nonlinearities and uncertainties. Their decomposition into subsystems, making them more manageable and hierarchically organized, is fundamental. Each of the subsystems consists of different interconnected replaceable components that perform different functions.With this in mind, we propose a diagnostic approach based on four types of knowledge: functional, structural, topological and behavioral.This approach, which includes detection and localization, exploits the representation of different knowledge to detect and isolate the source of failure. In order to eliminate any ambiguity of location, the addition of a timed automat allows, thanks to a temporal analysis, to efficiently identify the defective component(s). The proposed multimodel approach is organized around three algorithms.Modeling and failure analysis is illustrated on a cyber-physical system: the "RobAIR" telepresence robot. The different knowledge models were established with an analysis approach as well as the construction of the diagnostician based on previously defined signaturesThe implementation of Matlab's Simulink / Stateflow isolation and detection algorithms made it possible to build the diagnoser according to the proposed methodology and thus validate our approach by simulating the operation with random injection of various failures.The proposed analysis method was applied to the RobaIR robot's start-up tests with particular attention to the displacement part. The testing of all the robot's functionalities is done by programming the Arduino board. For this application, the detection and isolation algorithms have been supplemented by obstacle detection and failure mode identification.

The integration between the computing world and the physical world in a single system is called Cyber-Physical Systems (CPS). CPS systems aim to improve understanding and influence in physical phenomena and environmental behaviors by computing means. The interaction of the computing world with the physical world, through the use of sensors, actuators and network communication often leads to the accomplishment of highly complex and multidisciplinary projects. Project management is a practice that enhances the success probability of a project, monitoring and controlling relevant aspects to the project execution. Project Management Body of Knowledge (PMBOK) is a set of best practices regarding project management which addresses ten knowledge areas aiming to support project managers from any application domain. Although PMBOK proposes a generic approach, some specialized practices for a particular application domain may benefit highly challenging projects. In this context, this research work aims to propose a set of best practices specific for CPS systems development projects. The proposed approach is called CPS-PMBOK (junction of terms cyber-physical systems and project management body of knowledge) and is based on PMBOK\'s three knowledge areas: scope, human resource and stakeholder. CPS-PMBOK includes: \\textit a CPS characterization model which supports the understanding of the system to be developed; and \\textit specializations of these three PMBOK\'s knowledge areas, which provide a whole new process for the project scope management as well as specific improvements of well-known techniques for both the human resource management and the stakeholders management. The goal of CPS-PMBOK is to enhance project effectiveness and CPS quality, embracing both project manager and developers. To evaluate CPS-PMBOK effectiveness and adherence, the practices were presented for project managers and developers in a R\\&D company. The practices: pre-elaborated list of requirements, specialized team division and technical trust showed as more relevant for each respective knowledge area, according to managers. For developers, the review requirements process, cross training and technical trust seems to contribute more for its respective knowledge areas / A integração entre o mundo computacional e o mundo físico em um único sistema é chamada de Sistemas Ciberfísicos (CPS - do inglês \"Cyber-Physical Systems\'\'). Sistemas CPS visam melhorar o entendimento e a influência nos fenômenos físicos por meios computacionais. A interação do mundo computacional com o mundo físico, por meio de sensores, atuadores e redes de comunicação, frequentemente leva à realização de projetos de alta complexidade e multidisciplinares. Gestão de projetos é uma prática que aumenta as chances de sucesso de um projeto, monitorando e controlando aspectos relevantes da realização do projeto. PMBOK (Project Management Body of Knowledge) é uma combinação de boas práticas relacionadas à gestão de projetos que trata dez áreas de conhecimento visando auxiliar gerentes de projeto de qualquer área de aplicação. Embora PMBOK proponha uma abordagem genérica, algumas práticas especializadas para determinadas áreas de aplicação particulares podem beneficiar projetos altamente desafiadores. Neste contexto, este projeto de pesquisa visa propor um conjunto de boas práticas para projetos de desenvolvimento de sistemas CPS. Essa abordagem é chamada de CPS-PMBOK (junção dos termos em inglês: cyber-physical systems e project management body of knowledge) e é baseada em três áreas de conhecimento do PMBOK: escopo, recursos humanos e partes interessadas. CPS-PMBOK inclui: (i) um modelo de caracterização de sistemas CPS que auxilia o entendimento do sistema a ser desenvolvido e (ii) especializações dessas três áreas de conhecimento do PMBOK, que fornecem um inteiramente novo processo para a gestão de escopo do projeto assim como melhorias específicas de técnicas conhecidas do PMBOK para os processos de gestão de recursos humanos e de gestão de partes interessadas. O objetivo da CPS-PMBOK é melhorar a eficácia do projeto e a qualidade do sistema CPS desenvolvido, abrangendo tanto o gerente de projeto quanto os desenvolvedores. Para avaliar a efetividade e aderência da CPS-PMBOK, as práticas foram apresentadas para gerentes de projeto e desenvolvedores em uma empresa de P&D. As práticas: listas pré-elaboradas de requisitos, divisão de equipes especializadas e confiança técnica mostraram-se mais relevantes para cada respectiva área do conhecimento, segundo os gerentes. Para os desenvolvedores, o processo de revisar requisitos, treinamento cruzado e confiança técnica pareceram contribuir mais para suas respectivas áreas do conhecimento

A digital twin facilitates the means to monitor, understand, and optimize the functions of the physical entity and provides continuous feedback to improve quality of life, and Medical Cyber-Physical Systems (MCPS) is an integral part of this vision. Many studies focus on human motion to digitize data for further analysis. The literature review presented here emphasizes on gait analysis and gait events detection using wearable devices, which compare results by testing on different groups of individuals. Amongst those, there is a focus on digitizing activities for athletes and sports activities. However, there is a lack of research that address configurability for this type of MCPS. Adding new physical devices to an established MCPS requires manual configuration. Recent studies either solve the issue of users’ mobility by providing a wireless solution with local storage, or sacrifice mobility in order to provide real-time information through wired communication. However, group physical activity applications, such as sports coaching and group physiotherapy, use customized devices that need to be automatically configured in the system. In addition, these systems need to support mobility and real-time data presentation. To solve this problem, a framework is proposed to design a wellbeing Cyber-Physical System (CPS) that focuses on system configurability, providing real-time data of body sensor networks while supporting wireless and mobile communication. A communication protocol is proposed to allow seamless integration and communication of system components, and to enable bandwidth-conscious data transmission. As a proof of concept, a configurable CPS for gait activities monitoring is designed to read, visualize, and backup spatiotemporal data from one or more multi-sensory physical devices over conventional Wi-Fi and in real-time. Two experiments were performed using the implemented CPS. The first experiment was performed outdoors and tested if the CPS components would recognize each other and work seamlessly over foreign networks while providing usable information. The second experiment was performed in collaboration with the Health Sciences Department using our system and the Tekscan Strideway gait mat simultaneously to compare results and to ensure accuracy. In addition, this experiment tested configurability of the system by using different measurement devices for different users.

The integration between the computing world and the physical world in a single system is called Cyber-Physical Systems (CPS). CPS systems aim to improve understanding and influence in physical phenomena and environmental behaviors by computing means. The interaction of the computing world with the physical world, through the use of sensors, actuators and network communication often leads to the accomplishment of highly complex and multidisciplinary projects. Project management is a practice that enhances the success probability of a project, monitoring and controlling relevant aspects to the project execution. Project Management Body of Knowledge (PMBOK) is a set of best practices regarding project management which addresses ten knowledge areas aiming to support project managers from any application domain. Although PMBOK proposes a generic approach, some specialized practices for a particular application domain may benefit highly challenging projects. In this context, this research work aims to propose a set of best practices specific for CPS systems development projects. The proposed approach is called CPS-PMBOK (junction of terms cyber-physical systems and project management body of knowledge) and is based on PMBOK\'s three knowledge areas: scope, human resource and stakeholder. CPS-PMBOK includes: \\textit a CPS characterization model which supports the understanding of the system to be developed; and \\textit specializations of these three PMBOK\'s knowledge areas, which provide a whole new process for the project scope management as well as specific improvements of well-known techniques for both the human resource management and the stakeholders management. The goal of CPS-PMBOK is to enhance project effectiveness and CPS quality, embracing both project manager and developers. To evaluate CPS-PMBOK effectiveness and adherence, the practices were presented for project managers and developers in a R\\&D company. The practices: pre-elaborated list of requirements, specialized team division and technical trust showed as more relevant for each respective knowledge area, according to managers. For developers, the review requirements process, cross training and technical trust seems to contribute more for its respective knowledge areas / A integração entre o mundo computacional e o mundo físico em um único sistema é chamada de Sistemas Ciberfísicos (CPS - do inglês \"Cyber-Physical Systems\'\'). Sistemas CPS visam melhorar o entendimento e a influência nos fenômenos físicos por meios computacionais. A interação do mundo computacional com o mundo físico, por meio de sensores, atuadores e redes de comunicação, frequentemente leva à realização de projetos de alta complexidade e multidisciplinares. Gestão de projetos é uma prática que aumenta as chances de sucesso de um projeto, monitorando e controlando aspectos relevantes da realização do projeto. PMBOK (Project Management Body of Knowledge) é uma combinação de boas práticas relacionadas à gestão de projetos que trata dez áreas de conhecimento visando auxiliar gerentes de projeto de qualquer área de aplicação. Embora PMBOK proponha uma abordagem genérica, algumas práticas especializadas para determinadas áreas de aplicação particulares podem beneficiar projetos altamente desafiadores. Neste contexto, este projeto de pesquisa visa propor um conjunto de boas práticas para projetos de desenvolvimento de sistemas CPS. Essa abordagem é chamada de CPS-PMBOK (junção dos termos em inglês: cyber-physical systems e project management body of knowledge) e é baseada em três áreas de conhecimento do PMBOK: escopo, recursos humanos e partes interessadas. CPS-PMBOK inclui: (i) um modelo de caracterização de sistemas CPS que auxilia o entendimento do sistema a ser desenvolvido e (ii) especializações dessas três áreas de conhecimento do PMBOK, que fornecem um inteiramente novo processo para a gestão de escopo do projeto assim como melhorias específicas de técnicas conhecidas do PMBOK para os processos de gestão de recursos humanos e de gestão de partes interessadas. O objetivo da CPS-PMBOK é melhorar a eficácia do projeto e a qualidade do sistema CPS desenvolvido, abrangendo tanto o gerente de projeto quanto os desenvolvedores. Para avaliar a efetividade e aderência da CPS-PMBOK, as práticas foram apresentadas para gerentes de projeto e desenvolvedores em uma empresa de P&D. As práticas: listas pré-elaboradas de requisitos, divisão de equipes especializadas e confiança técnica mostraram-se mais relevantes para cada respectiva área do conhecimento, segundo os gerentes. Para os desenvolvedores, o processo de revisar requisitos, treinamento cruzado e confiança técnica pareceram contribuir mais para suas respectivas áreas do conhecimento

abstract: Automated driving systems are in an intensive research and development stage, and the companies developing these systems are targeting to deploy them on public roads in a very near future. Guaranteeing safe operation of these systems is crucial as they are planned to carry passengers and share the road with other vehicles and pedestrians. Yet, there is no agreed-upon approach on how and in what detail those systems should be tested. Different organizations have different testing approaches, and one common approach is to combine simulation-based testing with real-world driving. One of the expectations from fully-automated vehicles is never to cause an accident. However, an automated vehicle may not be able to avoid all collisions, e.g., the collisions caused by other road occupants. Hence, it is important for the system designers to understand the boundary case scenarios where an autonomous vehicle can no longer avoid a collision. Besides safety, there are other expectations from automated vehicles such as comfortable driving and minimal fuel consumption. All safety and functional expectations from an automated driving system should be captured with a set of system requirements. It is challenging to create requirements that are unambiguous and usable for the design, testing, and evaluation of automated driving systems. Another challenge is to define useful metrics for assessing the testing quality because in general, it is impossible to test every possible scenario. The goal of this dissertation is to formalize the theory for testing automated vehicles. Various methods for automatic test generation for automated-driving systems in simulation environments are presented and compared. The contributions presented in this dissertation include (i) new metrics that can be used to discover the boundary cases between safe and unsafe driving conditions, (ii) a new approach that combines combinatorial testing and optimization-guided test generation methods, (iii) approaches that utilize global optimization methods and random exploration to generate critical vehicle and pedestrian trajectories for testing purposes, (iv) a publicly-available simulation-based automated vehicle testing framework that enables application of the existing testing approaches in the literature, including the new approaches presented in this dissertation. / Dissertation/Thesis / Doctoral Dissertation Computer Engineering 2019

In the coming 20 years, unmanned aerial data collection will be of great importance to many sectors of civilian life. Of these systems, Personal Remote Sensing (PRS) Small Unmanned Aerial Systems (sUASs), which are designed for scientic data collection, will need special attention due to their low cost and high value for farming, scientic, and search-andrescue uses, among countless others. Cyber-Physical Systems (CPSs: large-scale, pervasive automated systems that tightly couple sensing and actuation through technology and the environment) can use sUASs as sensors and actuators, leading to even greater possibilities for benet from sUASs. However, this nascent robotic technology presents as many problems as possibilities due to the challenges surrounding the abilities of these systems to perform safely and eectively for personal, academic, and business use. For these systems, whose missions are dened by the data they are sent to collect, safe and reliable mission quality is of highest importance. Much like the dawning of civil manned aviation, civilian sUAS ights demand privacy, accountability, and other ethical factors for societal integration, while safety of the civilian National Airspace (NAS) is always of utmost importance. While the growing popularity of this technology will drive a great effort to integrate sUASs into the NAS, the only long-term solution to this integration problem is one of proper architecture. In this research, a set of architectural requirements for this integration is presented: the Architecture for Ethical Aerial Information Sensing or AERIS. AERIS provides a cohesive set of requirements for any architecture or set of architectures designed for safe, ethical, accurate aerial data collection. In addition to an overview and showcase of possibilities for sUAS-enabled CPSs, specific examples of AERIS-compatible sUAS architectures using various aerospace design methods are shown. Technical contributions include specic improvements to sUAS payload architecture and control software, inertial navigation and complementary lters, and online energy and health state estimation for lithium-polymer batteries in sUAS missions. Several existing sUASs are proled for their ability to comply with AERIS, and the possibilities of AERIS data-driven missions overall is addressed.

Building Automation System (BAS) is a complex distributed control system that is widely deployed in commercial, residential, industrial buildings for monitoring and controlling mechanical/electrical equipment. Through increasing industrial and technological advances, the control components of BAS are becoming increasingly interconnected. Along with potential benefits, integration also introduces new attack vectors, which tremendous increases safety and security risks in the control system. Historically, BAS lacks security design and relies on physical isolation and "security through obscurity". These methods are unacceptable with the "smart building" technologies. The industry needs to reevaluate the safety and security of the current building automation system, and design a comprehensive solution to provide integrity, reliability, and confidentiality on both system and network levels. This dissertation focuses on the system level in the effort to provide a reliable computing foundation for the devices and controllers. Leveraged on the preferred security features such as, robust modular design, small privilege code, and formal verifiability of microkernel architecture, this work describes a security enhanced operating system with built-in mandatory access control and a proxy-based communication framework for building automation controllers. This solution ensures policy-enforced communication and isolation between critical applications and non-critical applications in a potentially hostile cyber environment.