A Scalable Multitasking Wireless Sensor Network Testbed for Monitoring Indoor Human Comfort

Achieving occupants comfort in built environments is a major goal of modern building automation systems. Nonetheless, even a quantification of human comfort represents a significant challenge because of the number of physical quantities affecting it which, therefore, have to be tracked at suitable spatial and temporal resolution. Wireless sensor and actuator networks are increasingly considered an enabling technology for many monitoring and remote control tasks. Indeed, their reduced intrusiveness, low cost, and low power requirements represent attractive features for the design of monitoring and control infrastructures. In this paper we present a wireless sensor network testbed aimed at monitoring human comfort in a two-century-old building used as university campus. The proposed solution is based on sensor nodes with multitasking capabilities allowing concurrent execution of multiple tasks. Experimental evaluations highlight the flexibility and scalability of the adopted design which allows monitoring of heterogeneous parameters at different rates also permitting the coexistence of event driven and asynchronous operating modes

an open and modular hardware node for wireless sensor and body area networks

Health monitoring is nowadays one of the hottest markets due to the increasing interest in prevention and treatment of physical problems. In this context the development of wearable, wireless, open-source, and nonintrusive sensing solutions is still an open problem. Indeed, most of the existing commercial architectures are closed and provide little flexibility. In this paper, an open hardware architecture for designing a modular wireless sensor node for health monitoring is proposed. By separating the connection and sensing functions in two separate boards, compliant with the IEEE1451 standard, we add plug and play capabilities to analog transducers, while granting at the same time a high level of customization. As an additional contribution of the work, we developed a cosimulation tool which simplifies the physical connection with the hardware devices and provides support for complex systems. Finally, a wireless body area network for fall detection and health monitoring, based on wireless node prototypes realized according to the proposed architecture, is presented as an application scenario

Automation of garment assembly processes

Robotic automation in apparel manufacturing is reviewed and investigated. Gripper design for separation and de-stacking of batch cut fabric components is identified as an important factor in implementing such automation and a study of existing gripper mechanisms is presented. New de-stacking gripper designs and processes are described together with experimental results. Single fabric component handling, alignment and registration techniques are investigated. Some of these techniques are integrated within a demonstrator robotic garment assembly cell automating the common edge binding process. Performance results are reported

Leçons apprises via l'implémentation et la comparaison des performances de deux protocoles MAC / RDC sur différents systèmes d'exploitation pour réseaux de capteurs sans-fil

Implementing new, high-performance MAC/RDC protocols on WSN/IoT motes is a complex and requiring task; to do it efficiently, one has to encounter many challenges that need to be overcome using the best trade-off between various and often contradictory objectives.A first key point is the software platform used for implementation: many specialized OSes for WSN motes are available, each one with its own set of features. What are the most important features an OS can offer when trying to implement a new protocol into its network stack? What software platform did we choose according to these requirements?A second point is the availability of development tools facilitating implementation and debugging. Emulators and simulators are such tools. They dramatically help to develop and debug WSN/IoT software. Are they also adequate for performance evaluation of MAC/RDC protocols?Finally, what is the impact of implementation choices on the performance of the final software? To what extent does optimization influence actual results during evaluation?We propose, in this report, our answers to these questions; answers we had to give while building and testing an implementation of our own MAC/RDC protocol.L'implémentation de nouveaux protocoles MAC / RDC à hautes performances pour les noeuds de réseaux de capteurs sans-fil (WSN) et de l'Internet des Objets (IoT) est une tâche complexe et exigeante ; pour la réaliser efficacement, il est nécessaire de faire face à de nombreux défis à surmonter en trouvant le meilleur compromis entre des objectifs souvent contradictoires.Un premier point-clé est la plate-forme logicielle utilisée pour l'implémentation : de nombreux OS spécialisés pour les WSN sont disponibles, chacun ayant son propre ensemble de fonctionnalités. Quelles sont les fonctionnalités les plus importantes qu'un OS doit offrir pour faciliter l'implémentation d'un nouveau protocole dans sa pile réseau ? Quelle plate-forme logicielle avons nous choisie en fonction de ces besoins ?Un deuxième point-clé est la disponibilité d'outils de développement facilitant l'implémentation et le déboguage. Les émulateurs et simulateurs font partie de cette catégorie d'outils. Ils aident grandement au développement et au déboguage de logiciels pour les WSN et l'IoT. Sont-ils également adéquats pour l'évaluation des performances des protocoles MAC / RDC ?Enfin, quel est l'impact des choix d'implémentation sur les performances du logiciel terminé ? Jusqu'à quel point l'optimisation influence-t-elle les résultats réels obtenus durant l'évaluation ?Nous proposons, dans ce rapport, nos réponses à ces questions ; réponses que nous avons dû donner durant l'implémentation et les tests de notre propre protocole MAC / RDC

Overlay virtualized wireless sensor networks for application in industrial internet of things : a review

Abstract: In recent times, Wireless Sensor Networks (WSNs) are broadly applied in the Industrial Internet of Things (IIoT) in order to enhance the productivity and efficiency of existing and prospective manufacturing industries. In particular, an area of interest that concerns the use of WSNs in IIoT is the concept of sensor network virtualization and overlay networks. Both network virtualization and overlay networks are considered contemporary because they provide the capacity to create services and applications at the edge of existing virtual networks without changing the underlying infrastructure. This capability makes both network virtualization and overlay network services highly beneficial, particularly for the dynamic needs of IIoT based applications such as in smart industry applications, smart city, and smart home applications. Consequently, the study of both WSN virtualization and overlay networks has become highly patronized in the literature, leading to the growth and maturity of the research area. In line with this growth, this paper provides a review of the development made thus far concerning virtualized sensor networks, with emphasis on the application of overlay networks in IIoT. Principally, the process of virtualization in WSN is discussed along with its importance in IIoT applications. Different challenges in WSN are also presented along with possible solutions given by the use of virtualized WSNs. Further details are also presented concerning the use of overlay networks as the next step to supporting virtualization in shared sensor networks. Our discussion closes with an exposition of the existing challenges in the use of virtualized WSN for IIoT applications. In general, because overlay networks will be contributory to the future development and advancement of smart industrial and smart city applications, this review may be considered by researchers as a reference point for those particularly interested in the study of this growing field

An architecture for intelligent health assessment enabled IEEE 1451 compliant smart sensors

As systems become increasingly complex and costly, potential failure mechanisms and indicators are numerous and difficult to identify, while the cost of loss is very expensive - human lives, replacement units, and impacts to national security. In order to ensure the safety and long-term reliability of vehicles, structures, and devices attention must be directed toward the assessment and management of system health. System health is the key component that links data, information, and knowledge to action. Integrated Systems Health Management (ISHM) doctrine calls for comprehensive real-time health assessment and management of systems where the distillation of raw data into information takes place within sensors and actuators. This thesis develops novel field programmable health assessment capability for sensors and actuators in ISHM. Health assessment and feature extraction algorithms are implemented on a sensor or actuator through the Embedded Routine Manager (ERM) API. Algorithms are described using Health Electronic Datasheets (HEDS) to provide more flexible run-time operation. Interfacing is accomplished through IEEE Standard 1451 for Smart Sensors and Actuators, connecting ISHM with the instrumentation network of the future. These key elements are validated using exemplar algorithms to detect noise, spike, and flat-line events onboard the ISHM enabled Methane Thruster Testbed Project (MTTP) at NASA Stennis Space Center in Mississippi

Abstracting Application Development for Resource Constrained Wireless Sensor Networks

Ubiquitous computing is a concept whereby computing is distributed across smart objects surrounding users, creating ambient intelligence. Ubiquitous applications use technologies such as the Internet, sensors, actuators, embedded computers, wireless communication, and new user interfaces. The Internet-of-Things (IoT) is one of the key concepts in the realization of ubiquitous computing, whereby smart objects communicate with each other and the Internet. Further, Wireless Sensor Networks (WSNs) are a sub-group of IoT technologies that consist of geographically distributed devices or nodes, capable of sensing and actuating the environment.WSNs typically contain tens to thousands of nodes that organize and operate autonomously to perform application-dependent sensing and sensor data processing tasks. The projected applications require nodes to be small in physical size and low-cost, and have a long lifetime with limited energy resources, while performing complex computing and communications tasks. As a result, WSNs are complex distributed systems that are constrained by communications, computing and energy resources. WSN functionality is dynamic according to the environment and application requirements. Dynamic multitasking, task distribution, task injection, and software updates are required in field experiments for possibly thousands of nodes functioning in harsh environments.The development of WSN application software requires the abstraction of computing, communication, data access, and heterogeneous sensor data sources to reduce the complexities. Abstractions enable the faster development of new applications with a better reuse of existing software, as applications are composed of high-level tasks that use the services provided by the devices to execute the application logic.The main research question of this thesis is: What abstractions are needed for application development for resource constrained WSNs? This thesis models WSN abstractions with three levels that build on top of each other: 1) node abstraction, 2) network abstraction, and 3) infrastructure abstraction. The node abstraction hides the details in the use of the sensing, communication, and processing hardware. The network abstraction specifies methods of discovering and accessing services, and distributing processing in the network. The infrastructure abstraction unifies different sensing technologies and infrastructure computing platforms.As a contribution, this thesis presents the abstraction model with a review of each abstraction level. Several designs for each of the levels are tested and verified with proofs of concept and analyses of field experiments. The resulting designs consist of an operating system kernel, a software update method, a data unification interface, and all abstraction levels combining abstraction called an embedded cloud.The presented operating system kernel has a scalable overhead and provides a programming approach similar to a desktop computer operating system with threads and processes. An over-the-air update method combines low overhead and robust software updating with application task dissemination. The data unification interface homogenizes the access to the data of heterogeneous sensor networks. A unification model is used for various use cases by mapping everything as measurements. The embedded cloud allows resource constrained WSNs to share services and data, and expand resources with other technologies. The embedded cloud allows the distributed processing of applications according to the available services. The applications are implemented as processes using a hardware independent description language that can be executed on resource constrained WSNs. The lessons of practical field experimenting are analyzed to study the importance of the abstractions. Software complexities encountered in the field experiments highlight the need for suitable abstractions.The results of this thesis are tested using proof of concept implementations on real WSN hardware which is constrained by computing power in the order of a few MIPS, memory sizes of a few kilobytes, and small sized batteries. The results will remain usable in the future, as the vast amount, tight integration, and low-cost of future IoT devices require the combination of complex computation with resource constrained platforms

Multitasking on Wireless Sensor Networks

A Wireless Sensor Network (WSN) is a loose interconnection among distributed embedded devices called motes. Motes have constrained sensing, computing, and communicating resources and operate for a long period of time on a small energy supply. Although envisioned as a platform for facilitating and inspiring a new spectrum of applications, after a decade of research the WSN is limited to collecting data and sporadically updating system parameters. Programming other applications, including those that have real-time constraints, or designing WSNs operating with multiple applications require enhanced system architectures, new abstractions, and design methodologies. This dissertation introduces a system design methodology for multitasking on WSNs. It allows programmers to create an abstraction of a single, integrated system running with multiple tasks. Every task has a dedicated protocol stack. Thus, different tasks can have different computation logics and operate with different communication protocols. This facilitates the execution of heterogeneous applications on the same WSN and allows programmers to implement a variety of system services. The services that have been implemented provide energy-monitoring, tasks scheduling, and communication between the tasks. The experimental section evaluates implementations of the WSN software designed with the presented methodology. A new set of tools for testbed deployments is introduced and used to test examples of WSNs running with applications interacting with the physical world. Using remote testbeds with over 100 motes, the results show the feasibility of the proposed methodology in constructing a robust and scalable WSN system abstraction, which can improve the run-time performance of applications, such as data collection and point-to-point streaming