Plataforma de Integración Hardware-Software para Testbed de Redes de Sensores Inalámbricas

El campo de las redes de sensores inalámbricas ha cobrado gran importancia en esta última década ya que se han abierto diversas líneas de investigación con el fin de poder llevar a la práctica los conceptos y definiciones que envuelven el potencial de esta tecnología, y que está llamada a ser el futuro en la adquisición de datos de cualquier entorno físico de aplicación, mediante una herramienta basada en la autogestión y desatención durante largos periodos de tiempo, capacidad de tomar muestras cuando sea necesario a través de nodos sensores que se caractericen por el ahorro de energía y que puedan ser capaces de trabajar de forma autónoma durante meses, y que el carácter inalámbrico de la red a desplegar facilite las tareas de instalación y mantenimiento. Ello requiere que las condiciones para que una red de sensores inalámbrica sea la forma más viable de monitorizar un determinado entorno se base en ciertos requisitos de diseño, como lo es la baja tasa de transferencia de datos por parte de los nodos (estos deben ser capaces de transmitir la información recolectada desde los sensores y luego permanecer dormidos hasta una nueva adquisición), hardware enfocado al bajo consumo de energía con el fin de evitar cambios en la fuente de energía (baterías) durante largos periodos de tiempo, adaptabilidad al entorno de aplicación, flexibilidad y escalabilidad de la red si la aplicación hace necesario la inclusión de nuevos nodos o la modificación de los ya existentes, sin que ello suponga mayores dificultades en su desarrollo e implementación. El Centro de Electrónica industrial de la Universidad Politécnica de Madrid se incluye dentro de este último grupo, donde se ha diseñado una completa plataforma hardware para redes de sensores inalámbricas, con el fin de investigar las potencialidades, dificultades y retos que supone el realizar un despliegue de nodos inalámbricos en cumplimiento de características primordiales como autonomía, flexibilidad y escalabilidad de la red, además de la autogestión de los dispositivos que forman parte de ella. El presente trabajo de investigación se centra en cubrir estas necesidades, por lo que su principal objetivo es la creación de una plataforma de integración hardware-software que permita explotar todas las potencialidades de la arquitectura Cookies a través de una herramienta que facilite el despliegue, control y mantenimiento de una red de sensores inalámbrica, con el fin último de contar con un sistema total para el prototipado rápido de aplicaciones, soporte de pruebas de nuevos desarrollos y la posibilidad de implementación de dicha plataforma en cualquier entorno real, siendo sólo necesario realizar pequeños ajustes desde el más alto nivel de abstracción para que el sistema sea capaz de adaptarse por sí solo. Para cumplir tales propósitos y lograr una completa integración del sistema conjunto, ha sido necesario fijar principalmente tres líneas de trabajo que se enmarcan dentro de los objetivos específicos del presente proyecto, las cuales se detallan a continuación: Bibliotecas Software modulares: Basada en la filosofía de modularidad y flexibilidad de la plataforma hardware, se hace imprescindible primeramente contar con una plataforma software para el control de todos y cada uno de los elementos que componen al nodo Cookie, a partir de bloques funcionales que permitan gestionar desde el núcleo de procesamiento principal todas las características de la plataforma. Esto permitirá asegurar el control de los recursos hardware y facilitar la utilización de la plataforma desde un nivel más alto de abstracción, sólo con la configuración de parámetros estandarizados para el funcionamiento de la misma. Perfil de aplicación Cookies: Después de contar con bloques software que permitan controlar las características de bajo nivel del nodo inalámbrico, es necesario crear una herramienta para la estandarización de la forma en la que se comunican los dispositivos a nivel de aplicación, con el fin de gestionar las características y atributos de los nodos sensores de forma remota y facilitar el entendimiento entre ellos. Para ello, es necesario fijar ciertas directivas y reglas que permitan homogeneizar la gestión de tareas asociadas a los nodos Cookies, a través del diseño de un perfil de aplicación. Testbed para redes de sensores: Como resultado de las dos líneas anteriores de trabajo, la idea es contar con un instrumento que permita realizar pruebas reales haciendo uso de la plataforma de integración HW-SW, a partir de la gestión de todas las características y potencialidades que ofrece el perfil de aplicación creado y así facilitar el desarrollo de prototipos para aplicaciones basadas en redes de sensores inalámbricas, de forma rápida y eficiente. En este sentido, la idea es contar con un banco de pruebas basado en un despliegue de nodos Cookies que pueda ser controlado desde un ordenador central a través de una interfaz de usuario, desde el cual se lleva a cabo la monitorización y actuación sobre la red inalámbrica. Con el fin de lograr todos los objetivos planteados, ha sido necesario realizar un exhaustivo estudio de la plataforma hardware descrita anteriormente con el fin de conocer la forma en la que interactúan cada uno de los elementos incluidos en los nodos, así como la arquitectura y filosofía de los mismos, para poder llevar a cabo la integración con el software y, como se verá más adelante, realizar ajustes en el hardware para poder implementar correctamente las funcionalidades diseñadas. Por otro lado, ha sido necesario analizar las características de la especificación ZigBee y, sobre todo, las propiedades que posee el módulo de comunicaciones que incluye la plataforma hardware, el ETRX2, con el fin de poder realizar una configuración y gestión adecuada de los nodos a través de la red inalámbrica, aprovechando las posibilidades y recursos que ofrece dicho módulo

Testbed infrastructure for debugging, analyzing and optimizing WSN nodes based on a modular HW-SW architecture

The Internet of Things has emerged as one of the key aspects to the future of the Wireless Sensor Networ ks and their impact in new applications in real environments. This concept poses new challenges in the implementation, testing and assessment of efficient, robust and reliable technologies and prototypes under this paradigm. In this way, the run-time remote interaction with the deployment of hundreds of in-f ield nodes in which developers have to be able to control and manage the wireless network anywhere at any time also implies new objectives to be achieved in order to adapt or even create new HW-SW platforms. In this work, the design and implementation of a complete testbed infrastructure as a support tool for improving the effectiveness and the applicability of sensor nodes to real applications is presented, focused on the m odular architecture of the Cookie hardware platform and aiming to help developers to integrate and optimize the whole WSN system to the final applications in the real world

A reliable support tool for monitoring, testing and debugging wireless sensor cookie nodes

In this work a WSN Support Tool for developing, testing, monitoring and debugging new application prototypes in a reliable and robust way is proposed, by combining a Hardware -Software Integration Platform with the implementation of a parallel communication channel that helps users to interact to the experiments in runtime without interfering in the operation of the wireless network. As a pre-deployment tool, prototypes can be validated in a real environment before implementing them in the final application, aiming to increase the effectiveness and efficiency of the technology. This infrastructure is the support of CookieLab: a WSN testbed based on the Cookie Nodes Platform

Testbed architecture and framework for debugging wireless sensor networks

The Internet of Things has emerged as one of the key aspects for the future of the Wireless Sensor Networks and their impact on new applications in real environments. This concept poses new challenges in the implementation, testing and debugging of efficient, robust and reliable technologies under this paradigm, specially in a pre-deployment stage where HW-SW platform prototypes are to be optimized prior to their inclusion in actual deployments. In this work, the design and implementation of a complete testbed infrastructure as a support tool for improving the effectiveness and the applicability of sensor nodes to real systems is presented, focused on the modular architecture of the Cookie platform and aiming to help developers to integrate and improve the whole WSN operation to final real-world scenarios

3D-LIDAR Based Object Detection and Tracking on the Edge of IoT for Railway Level Crossing

Object detection is an essential technology for surveillance systems, particularly in areas with a high risk of accidents such as railway level crossings. To prevent future collisions, the system must detect and track any object that passes through the monitored area with high accuracy, and this process must be performed fulfilling real-time specifications. In this work, an edge IoT HW platform implementation capable of detecting and tracking objects in a railway level crossing scenario is proposed. The response of the system has to be calculated and sent from the proposed IoT platform to the train, so as to trigger a warning action to avoid a possible collision. The system uses a low-resolution 3D 16-channel LIDAR as a sensor that provides an accurate point cloud map with a large amount of data. The element used to process the information is a custom embedded edge platform with low computing resources and low-power consumption. This processing element is located as close as possible to the sensor, where data is generated to improve latency, privacy, and avoid bandwidth limitations, compared to performing processing in the cloud. Additionally, lightweight object detection and tracking algorithm is proposed in this work to process a large amount of information provided by the LIDAR, allowing to reach real-time specifications. The proposed method is validated quantitatively by carrying out implementation on a car road, emulating a railway level crossing

Modelling and planning reliable wireless sensor networks based on multi-objective optimization genetic algorithm with changeable length

Wireless sensor networks (WSN) have shown their potentials in various applications, which bring a lot of benefits to users from different working areas. However, due to the diversity of the deployed environments and resource constraints, it is difficult to predict the performance of a topology. Besides the connectivity, coverage, cost, network longevity and service quality should all be considered during the planning procedure. Therefore, efficiently planning a reliable WSN is a challenging task, which requires designers coping with comprehensive and interdisciplinary knowledge. A WSN planning method is proposed in this work to tackle the above mentioned challenges and efficiently deploying reliable WSNs. First of all, the above mentioned metrics are modeled more comprehensively and practically compared with other works. Especially 3D ray tracing method is used to model the radio link and sensing signal, which are sensitive to the obstruction of obstacles; network routing is constructed by using AODV protocol; the network longevity, packet delay and packet drop rate are obtained via simulating practical events in WSNet simulator, which to the best of our knowledge, is the first time that network simulator is involved in a planning algorithm. Moreover, a multi-objective optimization algorithm is developed to cater for the characteristics of WSNs. Network size is changeable during evolution, meanwhile the crossovers and mutations are limited by certain constraints to eliminate invalid modifications and improve the computation efficiency. The capability of providing multiple optimized solutions simultaneously allows users making their own decisions, and the results are more comprehensive optimized compared with other state-of-the-art algorithms. Practical WSN deployments are also realized for both indoor and outdoor environments and the measurements coincident well with the generated optimized topologies, which prove the efficiency and reliability of the proposed algorithm

Novel cluster-based routing protocol optimization approach for wireless sensor mesh networking

In this work, a novel and powerful mechanism for optimizing dynamic routing protocols in wireless se nsor mesh networking is deeply proposed and studied, by taking advantage and the benefits of flat-based routing techniques in combination with hierarchical strategies, so that a more efficient and energy/processing aware multi-path dissemination protocol is fully implemented. The communication and routing capabilities of W SN-based smart applications are key issues to be tackled in order to assure the reliability, scalability and long-term operability of the whole system. In order to accomplish such a challenging approach and targeting the on-site perf ormance analysis of routing protocols in real scenarios, a new intelligent, mobile and adaptable routing protocol simulator is also proposed, so that users are provided with a complete comparative study of different multi-hop mesh-based network deployments based on the design constraints and application requirements

Simulation-Based Virtual Cycle for Multi-Level Airport Analysis

The aeronautical industry is expanding after a period of economic turmoil. For this reason, a growing number of airports are facing capacity problems that can sometimes only be resolved by expanding infrastructure, with the inherent risks that such decisions create. In order to deal with uncertainty at different levels, it is necessary to have relevant tools during an expansion project or during the planning phases of new infrastructure. This article presents a methodology that combines simulation approaches with different description levels that complement each other when applied to the development of a new airport. The methodology is illustrated with an example that uses two models for an expansion project of an airport in The Netherlands. One model focuses on the operation of the airport from a high-level position, while the second focuses on other technical aspects of the operation that challenge the feasibility of the proposed configuration of the apron. The results show that by applying the methodology, analytical power is enhanced and the risk of making the wrong decisions is reduced. We identified the limitations that the future facility will have and the impact of the physical characteristics of the traffic that will operate in the airport. The methodology can be used for tackling different problems and studying particular performance indicators to help decision-makers take more informed decisions.Grupo de Transporte Aéreo - Grupo de Ingeniería Aplicada a la Industri

Simulation-Based Virtual Cycle for Multi-Level Airport Analysis

The aeronautical industry is expanding after a period of economic turmoil. For this reason, a growing number of airports are facing capacity problems that can sometimes only be resolved by expanding infrastructure, with the inherent risks that such decisions create. In order to deal with uncertainty at different levels, it is necessary to have relevant tools during an expansion project or during the planning phases of new infrastructure. This article presents a methodology that combines simulation approaches with different description levels that complement each other when applied to the development of a new airport. The methodology is illustrated with an example that uses two models for an expansion project of an airport in The Netherlands. One model focuses on the operation of the airport from a high-level position, while the second focuses on other technical aspects of the operation that challenge the feasibility of the proposed configuration of the apron. The results show that by applying the methodology, analytical power is enhanced and the risk of making the wrong decisions is reduced. We identified the limitations that the future facility will have and the impact of the physical characteristics of the traffic that will operate in the airport. The methodology can be used for tackling different problems and studying particular performance indicators to help decision-makers take more informed decisions.Grupo de Transporte Aéreo - Grupo de Ingeniería Aplicada a la Industri

A novel on-site deployment, commissioning and debugging technique to assess and validate WSN based smart systems

In this work a novel on-site toolset-based architecture for tackling the main challenges of deploying and commissioning large scale WSN-based systems is proposed. This is one of the first implementations that addresses a complete set of runtime algorithms to efficiently deploy sensor platforms in the target scenarios based on the inclusion of the real behavior of the nodes within the in-situ simulation chain, combined with the integration of runtime diagnosis and reprogramming strategies to analyze the performance of the deployment in-field