<p>Sampled-data supervisory control deals with timed discrete event systems (TDES) where the supervisors are to be implemented as sampled-data controllers. A sampled-data controller views the system as a series of inputs and outputs and is controlled by a periodic clock. It samples its inputs, changes state, and updates its outputs on each clock edge (the tick event). The sampled-data supervisory control framework provides a set of conditions that the TDES system must satisfy to ensure its correct behaviour in order to be implemented as sampled data controllers. A serious limitation for automatic verification of systems is the size of the system's synchronous product. To overcome this limitation, we propose the use of a compositional approach to the verification of sampled-data supervisory control. In this approach, first we recast the required conditions for sampled-data supervisory control in terms of other properties such as language inclusion, nonblocking or controllability, which already have existing compositional methods and algorithms. This makes the sampled-data properties suitable for compositional verification, considerably increasing the size of systems that can be handled using sampled-data supervisory control. We also develop and implement a set of algorithms for the compositional verification of these sampled-data properties. We provide an example of the SD Controlled Flexible Manufacturing System to test our algorithms.</p> / Master of Science (MSc)

Ce travail traite de l'évitement d'obstacles pour les robots mobiles à roues. D’abord, deux solutions sont proposées dans le cas d’un seul robot autonome. La première est une amélioration de la technique des champs de potentiel afin de contraster l’apparition de minima locaux. Le résultat se base sur l’application de la définition de l’ «Input-to-State Stability» pour des ensembles décomposables. Chaque fois que le robot mobile approche un minimum local l’introduction d’un contrôle dédié lui permet de l’éviter et de terminer la tâche. La deuxième solution se base sur l’utilisation de la technique du «Supervisory Control» qui permet de diviser la tâche principale en deux sous tâches : un algorithme de supervision gère deux signaux de commande, le premier en charge de faire atteindre la destination, le deuxième d’éviter les obstacles. Les deux signaux de commande permettent de compléter la mission en temps fini en assurant la robustesse par rapport aux perturbations représentant certaines dynamiques négligées. Les deux solutions ont été mises en service sur un robot mobile «Turtlebot 2». Pour contrôler une formation de type leader-follower qui puisse éviter collisions et obstacles, une modification de l’algorithme de supervision précédent a été proposée ; elle divise la tâche principale en trois sous-problèmes gérés par trois lois de commande. Le rôle du leader est adapté pour être la référence du groupe avec un rôle actif : ralentir la formation en cas de manœuvre d'évitement pour certains robots. La méthode proposée permet au groupe de se déplacer et à chaque agent d’éviter les obstacles, ou les collisions, de manière décentralisée / This dissertation work addresses the obstacle avoidance for wheeled mobile robots. The supervisory control framework coupled with the output regulation technique allowed to solve the obstacle avoidance problem and to formally prove the existence of an effective solution: two outputs for two objectives, reaching the goal and avoiding the obstacles. To have fast, reliable and robust results the designed control laws are finite-time, a particular class very appropriate to the purpose. The novelty of the approach lies in the easiness of the geometric approach to avoid the obstacle and on the formal proof provided under some assumptions. The solution have been thus extended to control a leader follower formation which, sustained from the previous result, uses two outputs but three controls to nail the problem. The Leader role is redesigned to be the reference of the group and not just the most advanced agent, moreover it has a active role slowing down the formation in case of collision avoidance manoeuvre for some robots. The proposed method, formally proven, makes the group move together and allow each agent to avoid obstacles or collision in a decentralized way. In addition, a further contribution of this dissertation, it is represented by a modification of the well known potential field method to avoid one of the common drawback of the method: the appearance of local minima. Control theory tools helps again to propose a solution that can be formally proven: the application of the definition of Input-to-State Stability (ISS) for decomposable sets allows to treat separate obstacles adding a perturbation which is able to move the trajectory away from a critic point

Master of Science / Department of Electrical and Computer Engineering / Caterina M. Scoglio / The need for reliable and quick communication in the power grid is growing and becoming more critical. With the Smart Grid initiative, an increasing number of intelligent devices, such as smart meters and new sensors, are being added to the grid. The traffic demand on the communications network increases as these new devices are being added. This can cause issues such as longer delay, dropped packets, and equipment failure. The power grid relies on this data to function properly. The power grid will lose reliability and will not be able to provide customers with power unless it has correct and timely data. The current communications network architecture needs to be evaluated and improved. In this thesis, a simulator program is developed to study the communications network. The simulation model is written in C++ and models the components of the communications network. The simulation results provide insight on how to design the communications network in order for the system to be robust from failures. We are using the simulator to study different topologies of the communications network. The communications network often has a simular topology to the power grid. This is because of right-a-ways and ownership of equipment. Modifying the topology of the communications network slightly can improve the performance of the network. Security of the communications network is a very important aspect. There is a risk of successful attacks on the communications network without the implementation of security protocols. Attacks can come from malicious users of the communications network or from entities outside the network. These attacks may lead to damaged equipment, loss of power to consumers, network overload, loss of data, and loss of privacy. This thesis presents a short overview of the major issues related to the security of the communications network. The department of Electrical and Computer Engineering (ECE) at Kansas State University (K-State) is working on developing a Smart Grid lab. Burns and McDonnell has collaborated with the ECE department at K-State to develop the Smart Grid Lab. This lab will be located inside of the ECE department. The lab will consist of both power grid equipment and network communication equipment. This thesis describes similar labs. It then describes the initial plan for the lab, which is currently in the planning stage.

Energy services companies (ESCOs) typically implement energy management systems (EMSs) as part of Demand-Side Management (DSM) projects on South African mines. After DSM project completion, the mine becomes responsible for maintaining the performance of the EMS. Due to a lack of experience in using specialised EMSs, mines typically contract ESCOs for EMS maintenance. However, maintaining a large number of EMSs remotely is a resource-intensive task because of time wasted on daily monitoring and travelling to perform on-site maintenance. For the same reason, remote maintenance technologies have become widely used to maintain cellular devices, vehicles and industrial equipment. Mine EMSs typically control production-critical systems that in turn ensure safe working conditions underground. EMSs execute highly specialised control philosophies to achieve electrical energy management, while ensuring safe and productive system operation. None of the work done on remote maintenance, however, provides an integrated solution to maintain the performance of a growing number of these specialised EMSs. As part of this study, a supervisory system was developed to optimise remote maintenance of different EMS technologies. The supervisory system builds on the fundamentals of existing remote maintenance technologies, complemented by comprehensive diagnostics of specialised EMS technologies. This is possible through automated diagnostics of EMS components, the control philosophy and overall EMS performance. Maintenance management forms part of the supervisory system to ensure that maintenance is performed with optimal efficiency. A system implementation was executed to prove the feasibility of the supervisory system. The functional operation of the system was verified with pre-set scenarios that simulated day-to-day operation and common fault diagnostic events. As part of the case studies conducted for this thesis, the supervisory system was integrated with three distinct EMS technologies implemented on South African mines. To support the results of these case studies, the system validation was extended through integrations with seven additional EMSs. For the first time, a supervisory assessed the condition of the EMS components, the control philosophy and DSM performance comprehensively. The results (obtained over a period of more than six months) indicated that the average operational availability of EMS components improved from 90% to 97%. The average EMS performance improved from 1.8 MW to 2.5 MW, an improvement of 39%. The resulting electricity cost reduction achieved on the case studies accumulated to approximately R6 million during the respective assessment periods. The supervisory system facilitated efficient EMS maintenance, thus reducing the risk of unsafe working conditions and production interruptions. The system also allowed maintenance personnel to improve the diagnostic process continually, thus aligning with the standards documented in ISO 50001:2011 (ISO, 2011) regarding continual improvement of electrical energy management initiatives. The new supervisory system is scalable, thus an ESCO can maintain the performance of a growing number of EMSs remotely. Results of this study support further supervisory system integration with compatible EMS technologies, and expansion to new EMS technologies. The modular design of the supervisory system provides a basis for the development of a cross-industry platform for maintaining EMS performance. / PhD (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2014

Energy services companies (ESCOs) typically implement energy management systems (EMSs) as part of Demand-Side Management (DSM) projects on South African mines. After DSM project completion, the mine becomes responsible for maintaining the performance of the EMS. Due to a lack of experience in using specialised EMSs, mines typically contract ESCOs for EMS maintenance. However, maintaining a large number of EMSs remotely is a resource-intensive task because of time wasted on daily monitoring and travelling to perform on-site maintenance. For the same reason, remote maintenance technologies have become widely used to maintain cellular devices, vehicles and industrial equipment. Mine EMSs typically control production-critical systems that in turn ensure safe working conditions underground. EMSs execute highly specialised control philosophies to achieve electrical energy management, while ensuring safe and productive system operation. None of the work done on remote maintenance, however, provides an integrated solution to maintain the performance of a growing number of these specialised EMSs. As part of this study, a supervisory system was developed to optimise remote maintenance of different EMS technologies. The supervisory system builds on the fundamentals of existing remote maintenance technologies, complemented by comprehensive diagnostics of specialised EMS technologies. This is possible through automated diagnostics of EMS components, the control philosophy and overall EMS performance. Maintenance management forms part of the supervisory system to ensure that maintenance is performed with optimal efficiency. A system implementation was executed to prove the feasibility of the supervisory system. The functional operation of the system was verified with pre-set scenarios that simulated day-to-day operation and common fault diagnostic events. As part of the case studies conducted for this thesis, the supervisory system was integrated with three distinct EMS technologies implemented on South African mines. To support the results of these case studies, the system validation was extended through integrations with seven additional EMSs. For the first time, a supervisory assessed the condition of the EMS components, the control philosophy and DSM performance comprehensively. The results (obtained over a period of more than six months) indicated that the average operational availability of EMS components improved from 90% to 97%. The average EMS performance improved from 1.8 MW to 2.5 MW, an improvement of 39%. The resulting electricity cost reduction achieved on the case studies accumulated to approximately R6 million during the respective assessment periods. The supervisory system facilitated efficient EMS maintenance, thus reducing the risk of unsafe working conditions and production interruptions. The system also allowed maintenance personnel to improve the diagnostic process continually, thus aligning with the standards documented in ISO 50001:2011 (ISO, 2011) regarding continual improvement of electrical energy management initiatives. The new supervisory system is scalable, thus an ESCO can maintain the performance of a growing number of EMSs remotely. Results of this study support further supervisory system integration with compatible EMS technologies, and expansion to new EMS technologies. The modular design of the supervisory system provides a basis for the development of a cross-industry platform for maintaining EMS performance. / PhD (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2014

Submitted in fulfillment of the academic requirements for the Degree Master of Engineering (Electronic), Department of Electronic Engineering, Durban University of Technology, Durban, South Africa, 2016. / The proposed supervisory control and data acquisition solution is intended to gather data from all sub-systems and provide control commands related to the Indlebe Radio Telescope. Currently the control commands are executed from the command line prompt of the Skypipe software. These control commands are used to change the elevation angle of the antenna. The supervisory control and data acquisition system will be interfaced to sub-systems namely; a programmable logic controller, a weather station, an uninterruptible power supply and a camera. It will be used to manually or automatically control the elevation angle of the antenna, includes a menu structure that allows for easy navigation to the sub-systems and allows for trending, alarming, logging and monitoring of all system parameters. The proposed system will mitigate the lack of information on the existing system. A global system for mobile communication unit has also been installed to monitor the temperature within the Indlebe control room, detect a power failure and communicate this information to supervisors, using its short message service option. Implementing a solution of this nature means that all data from the various sub-systems are brought together, giving a single platform to monitor data and provide manual and automatic control functionality. Problem solving, understanding and maintenance of the system will also become easier. / D

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The Coal to Liquid facility, Sasol, Secunda operates as a train of processes. Disturbances and capacity restrictions can occur throughout the plant and the throughput fluctuates whenever disturbances occur. When capacity restrictions occur in a subplant and more substances enter the sub-plant than can be processed, the extra substances are flared or dumped and therefore lost. To reduce losses and extra costs and to maximise the throughput of the whole plant, supervisory control is implemented over the whole plant system. Each process in the process train is controlled with regulatory controllers and the overall process is then controlled with a supervisory controller. These two sets of controllers operate in two different layers of control, with the regulatory controllers the faster inner layer. The supervisory control is the outer layer of the two control layers. The supervisory controller takes over the work of the human operator by deciding on the changes in total throughput as well as the set points for each individual process. These set points for each process are then followed with the regulatory controllers. For the regulatory control of the system, different control methods are investigated and compared. The different control methods that are looked at are PI control, Linearised State Feedback control, Fuzzy Logic control and Model Reference Adaptive Control. After an investigation into the various control methods Fuzzy Logic control was chosen for the regulatory as well as the supervisory control levels. Fuzzy Logic control is a rule based control method. Fuzzy variables are everyday terms such as very slow or nearly full. These terms are easy to understand by the operator and multi-variable control is possible with Fuzzy Logic control without an accurate mathematical representation of the system. These facts made Fuzzy Logic control ideal for this implementation. To improve the profit of the Coal to Liquid facility the throughput was maximised. The combination of regulatory and supervisory controllers minimised losses and rejected disturbances. This resulted in a smoother output with maximum profit. / AFRIKAANSE OPSOMMING: Die Steenkool-na-Olie fasiliteit, Sasol, Secunda funksioneer as ’n trein van prosesse. Versteurings en kapasiteit beperkings kan deur die hele aanleg voorkom en die deurset wissel voortdurend wanneer versteurings voorkom. Wanneer kapasiteit beperkings voorkom in ’n aanleg en meer stowwe word in die aanleg ingestuur as wat dit kan verwerk, word die ekstra stowwe gestort en dit gaan verlore. Om verliese en kostes te verminder en om die deurset van die hele aanleg te vergroot, is oorhoofse beheer geïmplementeer oor die hele stelsel. Elke proses in die trein van chemiese prosesse word beheer met regulerende beheerders. Die totale proses word dan beheer met ’n oorhoofse beheerder. Hierdie twee tipes beheerders funksioneer in twee lae van beheer met die regulerende beheerders die vinniger binneste laag. Die oorhoofse beheerder vorm die buitenste laag van die twee beheer lae en neem die werk van die menslike operateur oor deur die veranderinge in die totale deurset, sowel as die stelpunte vir elke afsonderlike proses, te bepaal. Hierdie stelpunte vir elke proses word dan met die regulerende beheerders gevolg. Verskillende beheer metodes is ondersoek vir die regulerende beheer van die stelsel. Die verskillende beheer metodes waarna gekyk word, is PI beheer, Geliniariseerde Toestands Terugvoer beheer, Wasige Logiese beheer en Model Verwysing Aanpassende beheer. Na ’n ondersoek na die verskillende beheer metodes is Wasige Logiese beheer gekies vir die regulerende asook die oorhoofse beheer. Wasige Logiese beheer is ’n reël gebasseerde beheer metode. Wasige Logika veranderlikes is alledaagse terme soos baie stadig of byna vol. Hierdie terme is maklik om te verstaan deur die operateur. Meervoudige-veranderlike beheer is moontlik met Wasige Logiese beheer sonder ’n akkurate wiskundige voorstelling van die stelsel. Hierdie feite maak Wasige Logiese beheer ideaal vir hierdie doel. Om die wins van die Steenkool-na-Olie fasiliteit te verbeter, is die deurset gemaksimeer. Die kombinasie van regulerende- en toesighoudende beheerders beperk verliese en verwerp versteurings. Dit lei tot ’n gladder uitset en ’n maksimum wins.

This study examined the supervisory interactions of past and present residence life staff members, specifically, the implications of race on the residence life professional (HD)/residence life student staff member (RA) supervisory relationship. College and university residence halls provide some of the most diverse environments that individuals will encounter as they move through life (Amada, 1994; Jaeger & Caison, 2005). It is in these spaces that individuals learn the most about themselves and others. Thus, learning to navigate multicultural interactions is critical. Facilitated by residence life staff, this knowledge serves as preparation for the actual experiences and situations students will face once they are in the "real world." Although some areas of the higher education literature were limited, the literature review supported the role that residence life staff members have in preparing student staff members (whom are also residents) for the workplace. Learning how to handle situations in the workplace where there are differences such as language, race/ethnicity, culture, or values and beliefs will aid in positive interactions with others and ultimately contribute to a better working environment--inside and outside of the residence halls. Qualitative methods were used for this study because of their attention to vivid and layered descriptions. These descriptions give voice to a person's experiences and interactions and help them make meaning of their own worlds. As a result of residence life staff members living where they work, the most appropriate way to further examine their life experiences was through a phenomenological lens. In addition to the aforementioned qualitative methods, modified versions of quantitative instruments from an earlier study (Ladany, Brittan-Powell, & Pannu, 1997) and two other scales (Helms & Carter; 1990; Helms & Parham, 1996) were used to measure the racial identity development of the participants. These inventories relied on participants to self-report their perceptions. After these assessments were completed, interviews were conducted with 10 randomly selected participants (five RAs and five HDs). Five themes emerged from these participant interviews: prestige, protection, privilege, proximity, and preparedness. / text

Approved for public release; distribution is unlimited / Two recent trends have raised concerns about the security and stability of Supervisory Control and Data Acquisition (SCADA) systems. The first is a move to define standard interfaces and communications protocols in support of cross-vendor compatibility and modularity. The second is a move to connect nodes in a SCADA system to open networks such as the Internet. Recent failures of critical infrastructure SCADA systems highlight these concerns. To ensure continued operations in times of crisis, SCADA systems, particularly those operating in our critical infrastructure, must be secured. Developing an abstract generic framework for defining and understanding SCADA systems is a necessary first step. A framework can provide the tools to understand the system's functions and capabilities, and how components in the system relate and interface with each other. This thesis examines and describes SCADA systems, their components, and commonly used communications protocols. It presents a matrix approach to describing and defining the features, functions and capabilities of a SCADA system. Two small SCADA systems, using industry standard components and simulating real world applications, were designed and constructed for this thesis to provide context for applying the matrix approach. / Captain, United States Marine Corps

Attachment theory has established itself as applicable to many types of relationships, encompassing caregiver-child, romantic, interpersonal, and psychotherapeutic interactions. This project sought to investigate the application of attachment theory to clinical supervision. Using suggestions put forth in previous work by Watkins and Riggs, this study examined the dyadic interactions inherent in both supervision and attachment. Using the working alliance as determination of the quality of supervision, attachment styles, leader-follower attachment, and attachment-based expectations were explored as predictors for supervisor-trainee dyad outcome in a training clinic for doctoral psychology students. The study design is longitudinal and prospective. Findings indicate the necessity of measurement of supervisory-specific attachment rather than general attachment, the stability of working alliance over time, and the large contribution of the leader-member attachment framework to the understanding of supervisory attachment. Implications include the importance of maintaining hierarchical, evaluative boundaries within supervisory relationship, consistent with a leader-follower dynamic.