A Scalable and Secure System Architecture for Smart Buildings THÈSE NO 7905 (2017) PRÉSENTÉE LE 20 OCTOBRE 2017 À LA FACULTÉ DES SCIENCES ET TECHNIQUES DE L'INGÉNIEUR GROUPE KAYAL PROGRAMME DOCTORAL EN MICROSYSTÈMES ET MICROÉLECTRONIQUE ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR Georgios LILIS acceptée sur proposition du jury: Dr A. Schmid, président du jury Prof. M. Kayal, directeur de thèse Dr A. Sanfilippo, rapporteur Dr F. Lo Conte, rapporteur Dr S.-R. Cherkaoui, rapporteur Suisse 2017 What does not kill me, makes me stronger. — Friedrich Nietzsche Acknowledgements The execution of any major project is a considerable undertaking which necessitates collaboration and support. This research work is certainly not an exemption. There are remarkable people behind this work to whom I am grateful, and that deserve to be acknowledged. It was a pleasure to work with, discuss, and receive their support during the past four years. First of all, I would like to thank my thesis supervisor Prof. Maher Kayal for the excellent opportunity to conduct my research under his guidance and support. His trust and the research freedom throughout this process have been imperative for the success of this multidisciplinary engineering thesis. Moreover, I would like to acknowledge Dr. Fabrizio Lo Conte and Dr. Laurent Fabre from eSMART Technologies SA for their practical ideas, insights, and expertise that greatly assisted my research. As a member of electronics laboratory, I greatly enjoyed the collaboration and brainstorming with my fellow colleagues. Firstly, I would like to thank my long-term officemates for the many moments we shared together while working closely on the Smart Building project, Gilbert Conus and Nastaran Asadi Zanjani. Secondly, I am especially grateful to Dr. Theodoros Kyriakidis and Dr. Guillaume Lanz with whom I have had the pleasure to work with; their advice, support, and the open-ended discussions we shared together are deeply appreciated. I would also like to mention and thank Olivier Van Cutsem, his research contributions, motivation, and feedback have been invaluable for the success of my research work. I would like finally to thank my good friends and former officemates who helped me get a great start in the postgraduate life: Dr. Lucian Barbut, Dr. Maria-Anna Chalkiadaki, Dr. Farzan Jazaeri, and Dr. Anurag Mangla. This thesis would not have been possible without the Greek, Swiss, and international friends who contributed, each on their own way, to this work. I would like to say to all of you, a strong "thank you"! I would also like to thank my partner Evangelia for her constant encouragement and support to address my concerns, anxieties, and frustration that a Ph.D. journey brings. Thank you for making this thesis possible. Finally, I would like to express my deepest gratitude to my family, my sister Anastasia and my parents Konstantinos and Chrysoula who have supported me, despite the distance. Their love and guidance are with me in whatever I pursue. Lausanne, 28 July 2017 G.L. i Abstract Recent years has seen profound changes in building technologies both in Europe and worldwide. With the emergence of Smart Grid and Smart City concepts, the Smart Building has attracted considerable attention and rapid development. The introduction of novel information and communication technologies (ICT) enables an optimized resource utilization while improving the building performance and occupants’ satisfaction over a broad spectrum of operations. However, literature and industry have drawn attention to certain barriers and challenges that inhibit its universal adoption. The Smart Building is a cyber-physical system, which as a whole is more than the sum of its parts. The heterogeneous combination of systems, processes, and practices requires a multidisciplinary research. This work proposes and validates a systems engineering approach to the investigation of the identified challenges and the development of a viable architecture for the future Smart Building. Firstly, a data model for the building management system (BMS) enables a semantic abstraction of both the ICT and the building construction. A high-level application programming interface (API) facilitates the creation of generic management algorithms and external applications, independent from each Smart Building instance, promoting the intelligence portability and lowering the cost. Moreover, the proposed architecture ensures the scalability regardless of the occupant activities and the complexity of the optimization algorithms. Secondly, a real-time message-oriented middleware, as a distributed embedded architecture within the building, empowers the interoperability of the ICT devices and networks and their integration into the BMS. The middleware scales to any building construction regardless of the devices’ performance and connectivity limitations, while a secure architecture ensures the integrity of data and operations. An extensive performance and energy efficiency study validates the proposed design. A "building-in-the-loop" emulation system, based on discrete-event simulation, virtualizes the Smart Building elements (e.g., loads, storage, generation, sensors, actuators, users, etc.). The high integration with the message-oriented middleware keeps the BMS agnostic to the virtual nature of the emulated instances. Its cooperative multitasking and immerse parallelism allow the concurrent emulation of hundreds of elements in real time. The virtualization facilitates the development of energy management strategies and financial viability studies on the exact building and occupant activities without a prior investment in the necessary infrastructure. iii Abstract This work concludes with a holistic system evaluation using a case study of a university building as a practical retrofitting estimation. It illustrates the system deployment, and highlights how a currently under development energy management system utilizes the BMS and its data analytics for demand-side management applications. Key words: smart building, intelligent building, systems thinking, scalable architectures, energy management, building management systems, building data model, real-time architectures, distributed computing, message-oriented middleware, ICT interoperability architectures, discrete event system, parallel architectures, building emulation iv Résumé Ces dernières années ont connu d’importants changements dans les domaines liés aux bâtiments, aussi bien en Europe que dans le monde entier. L’émergence des concepts tels que le réseau électrique intelligent, de la ville intelligente et du bâtiment intelligent a attiré une attention considérable et, par conséquent, a mené à un développement rapide. Le développement des nouvelles technologies de l’information et de la communication (TIC) permet progressivement une utilisation optimisée des ressources tout en améliorant le rendement énergétique du bâtiment et la satisfaction des occupants sur un large éventail d’opérations. Cependant, la littérature et l’industrie ont mis en évidence certains obstacles et défis, qui empêchent leur adoption universelle. Le bâtiment intelligent est un système cyber-physique qui, dans son ensemble, représente une entité plus vaste que la somme de ses parties. La combinaison hétérogène de systèmes, d’algorithmes et d’interactions le constituant nécessite une recherche multidisciplinaire approfondie. Ce travail propose et valide une approche d’ingénierie des systèmes visant à répondre aux défis identifiés ainsi que le développement d’une architecture viable pour le bâtiment intelligent du futur. Tout d’abord, un modèle de données pour le système de gestion de bâtiments (BMS) a été développé afin d’abstraire la sémantique des TIC et la structure géométrique du bâtiment. Une interface de programmation d’applications de haut niveau (API) facilite la création d’algorithmes génériques de gestion de ressources et d’applications externes. Ces dernières sont ainsi indépendantes de toute instance du bâtiment intelligent, favorisant la portabilité de l’intelligence et réduisant de surcroît le coût. En outre, la répartition de charge et la virtualisation assurent l’élasticité du système, indépendamment des activités des occupants et de la complexité des algorithmes d’optimisation. Ensuite, un middleware temps-réel et orienté message assure l’interopérabilité des périphériques, des réseaux TIC et leur intégration après du BMS. Son architecture embarquée et distribuée au sein du bâtiment lui confère de nombreuses propriétés indispensables au bâtiment intelligent du futur. Le middleware s’adapte à n’importe quelle structure de bâtiment, indépendamment des performances des périphériques et des limitations de connectivité, tandis qu’une architecture sécurisée garantit l’intégrité des données et des opérations. Une étude approfondie de l’efficacité énergétique et la performance du BMS valide la conception proposée. v Résumé Un système d’émulation de « bâtiment-dans-la-boucle » virtualise les éléments dominants du bâtiment intelligent (par exemple, charges, stockage, génération, capteurs, actionneurs, utilisateurs, etc.). L’émulateur, basé sur une simulation d’événements discrets, est directement intégré dans le middleware, garantissant de la sorte une abstraction de la nature virtuelle des instances émulées vis-à-vis du BMS. Les entités virtuelles évoluent dans un environnement multitâche coopératif et son important parallélisme permet l’émulation simultanée de centaines d’éléments en temps réel.