1,720,976 research outputs found
Differentiation and Localization of Ground RF Transmitters Through RSSI Measures From a UAV
No full textLow-altitude Unmanned Aerial Vehicles (UAVs) are a valuable solution for data gathering, surveillance, warfare, and mapping. In these applications, differentiating and estimating the position of ground Radio Frequency (RF) emitters is pivotal. In order to achieve this, we define an experimental setup based on Received Signal Strength Indicator (RSSI) collected by a single UAV at different points of a predefined trajectory. The experimental setup is evaluated for the two unlicensed frequency bands of 2.4GHz and 865MHz with and without interference, respectively. We show that the application of the maximum likelihood algorithm to the RSSI measures collected in experiments conducted in rural areas gives a mean absolute localization error of about 5m and 4m for a single transmitter with and without interference, respectively. A threshold-based technique is proposed to improve the accuracy in the presence of interference. For multiple transmitters, the RSSI data are divided into clusters and fed into a localization algorithm. A k-means clustering algorithm eliminates user intervention and identifies the number of RF emitters in the area. As a further contribution of the paper, we performed a validation phase where the UAV flight path and data collection are simulated using the QuaDRiGa realistic radio impulse channel model
Experimental Jamming Detection Using Machine Learning in IEEE 802.11 Enterprise Networks
No full textExperimental UAV-Aided RSSI Localization of a Ground RF Emitter in 865 MHz and 2.4 GHz Bands
Full text linkUnmanned Aerial Vehicles (UAVs) can be used as low altitude platforms in several applications. In this paper, we propose their use to localize a ground Radio Frequency (RF) emitter by collecting measures of the Received Signal Strength Indicator (RSSI) at different positions. The main contribution of the work consists in the definition of an experimental setup for the simultaneous measures of RSSI and receiver position. The RSSI is measured by an actual transceiver, the Adalm Pluto Software Defined Radio (SDR) development board, programmed with the open-source software GNU Radio. The position is provided by GPS and Inertial Measuring Unit (IMU) sensors on the drone. The measures are acquired in the 865MHz Short Range Device (SRD) and 2.4 GHz Industrial Scientific Medical (ISM) unlicensed frequency bands. Since the ISM measures can be affected by interference generated by different sources (e.g. Wi-Fi access points and UAV controller), the SRD band is exploited for collecting the RSSI measures with less interference. A maximum likelihood (ML) algorithm is applied to the collected data for estimating the transmitter location. For the considered setup we show that the mean absolute localization error is around 4m without interference and 5m with interference. A threshold-based technique is proposed to improve the accuracy in presence of interference
Redundancy and Synchronisation Management in Mission- and Time-Critical Wireless Sensor Networks
Full text linkFault Recovery in Time-Synchronized Mission Critical ZigBee-Based Wireless Sensor Networks
Full text linkA redundant gateway prototype for wireless avionic sensor networks
No full textWireless Sensor Network (WSN) technologies provide advantages that allow them to replace traditional wired systems in an ever growing number of applications. This paper describes the design of a WSN for mission critical applications such as the case of avionics, in which data collected from the sensors can be delivered to a cloud application through multiple independent gateways, thereby increasing data availability in presence of failures. Since the same data might be distributed along multiple paths, system-wide synchronization must be provided in order to guarantee data consistency. A heartbeat protocol is introduced along each path in order to guarantee timely detection of any single failure. We present a solution that can be implemented using open source software and commercial off-the-shelf hardware, which makes this approach viable for networks with a large number of heterogeneous sensors. Results reported in this paper show some sample measurements as well as the performance evaluation for our heartbeat algorithm in terms of latency between a failure and a full recovery of the system
A novel technique for ZigBee coordinator failure recovery and its impact on timing synchronization
No full textIn mission critical wireless sensor networks (WSNs) accurate timestamping of the occurrence of events measured by the sensor nodes is often required together with a high degree of reliability. While precise timestamping requires synchronization of the sensor nodes, reliability is obtained by adding redundancy in all potential single point of failure nodes. In this paper, we focus on a ZigBee-based WSN using two personal area network (PAN) coordinators with different PAN identifiers (IDs) and, for this configuration, we propose a solution where if the primary PAN coordinator goes down, connections are transferred to the other by changing the PAN ID of the nodes. Our proposed solution provides significant gains in terms of recovery speed and timing synchronization accuracy in comparison to a solution that is proposed in the literature
A Communication Protocol Design aimed at a Multi-Agent System Framework for Miniaturized Satellite Systems
Full text linkIn recent years space-science and exploration have become more accessible due to the popularization of the concept of CubeSats. CubeSats are being used as a result of their convenient size and weight requirements, allowing for target missions to be designed, developed, and launched with a significant reduction of costs compared to traditional space missions. Furthermore, the development of target missions has become more intricate, forcing a shift in the traditional notion of using a centralized control architecture to a distributed architecture. A distributed architecture tackles the problem of a possible functionality loss over the control unit. This paper describes the extension of capabilities of the Multi-Agent Systems Framework for Embedded Systems (MAES). This extension provides MAES framework with the ability to perform inter-platform communication, so now the control unit architecture can be broadened allowing agents from different platforms to interact and perform cooperatively different routines designed by the developer, so it is not limited to the capabilities of just one platform. Moreover, this paper shows the results of the experimental setup showing the precision of inter-platform message exchange and the relationship between the delay of the exchange of inter-platform messages and the number of agents that are simultaneously running on each platform.En los últimos años, la ciencia espacial y la exploración se han vuelto más accesibles debido a la popularización del concepto de CubeSats. Los CubeSats se está utilizando debido a sus convenientes requisitos de tamaño y peso, lo que permite que misiones especificas se diseñen, desarrollen y lancen con una reducción significativa de los costos en comparación con las misiones espaciales tradicionales. Además, el desarrollo de misiones específicas se ha vuelto más complejo, forzando un cambio en la noción tradicional de usar una arquitectura de control centralizada para una arquitectura distribuida. Una arquitectura distribuida resuelve el problema de una posible pérdida de funcionalidad en la unidad de control. Este documento describe la extensión de las capacidades del frameworkde sistemas multiagentes para sistemas embebidos (MAES). Esta extensión proporciona al framework MAES la capacidad de realizar comunicaciones entre plataformas, de modo que ahora la arquitectura de la unidad de control puede ampliarse, permitiendo a los agentes de diferentes plataformas interactuar y realizar de forma cooperativa diferentes rutinas diseñadas por el desarrollador, por lo que no se está limitado a las capacidades de solo una plataforma. Asimismo, este documento muestra los resultados de la configuración experimental que muestra la precisión del intercambio de mensajes entre plataformas y la relación entre el retraso del intercambio de mensajes entre plataformas y la cantidad de agentes que se ejecutan simultáneamente en cada plataforma
Addressing food waste through technology: deploying Raspberry Pi for local database solutions
No full textLAUREA MAGISTRALELo spreco alimentare rappresenta una significativa sfida globale, che coinvolge milioni di individui in tutto il mondo in ogni fase della catena di approvvigionamento alimentare, dalla produzione al consumo. Recenti dati provenienti dall'Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura (FAO) rivelano statistiche allarmanti: oltre 800 milioni di persone soffrono di fame e malnutrizione a livello globale, mentre circa un terzo della produzione alimentare mondiale viene perso o sprecato annualmente, per un totale di 2,5 miliardi di tonnellate. Nonostante vari fattori ambientali, politici ed economici influenzino i processi di produzione alimentare, lo spreco alimentare persiste come una questione critica con profonde implicazioni per la distribuzione e la conservazione del cibo. Questo squilibrio sottolinea l'urgente necessità di ideare soluzioni efficaci per garantire una corretta allocazione delle risorse alimentari e affrontare il problema dello spreco alimentare.
In questo contesto, la ricerca si propone di adattare e integrare il codice di due progetti già esistenti: uno basato su HTML per il tracciamento della ridistribuzione degli alimenti e l'altro un'applicazione Android per monitorare le fasi di donazione e distribuzione degli alimenti in eccesso. Entrambi i progetti fanno uso del database MongoDB Atlas per la gestione dei dati. Tuttavia, l'obiettivo è quello di migrare l'archiviazione dei dati su un database locale ospitato sul Raspberry Pi, presentando un'alternativa più economica e versatile per affrontare tale questione.
L'utilizzo del Raspberry Pi come server per un database locale richiede la configurazione e l'ottimizzazione del sistema, nonché la modifica del codice delle applicazioni esistenti per consentire loro di interagire direttamente con il database locale. Sarà necessario esaminare le migliori pratiche e le sfide note nell'ambito dell'hosting di database e dello sviluppo di applicazioni web su piattaforme embedded come il Raspberry Pi. Questo approccio non solo si propone di ridurre lo spreco alimentare, ma mira anche a fornire una soluzione tecnologicamente innovativa e sostenibile per migliorare la gestione e la distribuzione degli alimenti.Food waste is a major international problem that affects millions of people around the globe. It occurs throughout the whole production chain, from farm to harvest to retailer to consumer. According to recent statistics released by the Food and Agriculture Organization (FAO) of the United Nations, more than 800 million people worldwide suffer from hunger and malnutrition, and around one-third of the world's food supply is wasted or lost, amounting to 2.5 billion tonnes of food wasted yearly. Though environmental, political and economic problems affect the process of food production, food waste remains a critical aspect that heavily impacts the food distribution and preservation chain. This imbalance underscores the urgent need to devise effective solutions to ensure proper allocation of food resources and address the issue of food waste.
In this context, the research aims to adapt and integrate the code of two existing projects: one based on HTML for tracking food redistribution and the other an Android application for monitoring the phases of food donation and distribution. Both projects make use of the MongoDB Atlas database for data management. However, the objective is to migrate the data storage to a local database hosted on the Raspberry Pi, presenting a more economical and versatile alternative to address this issue.
Using the Raspberry Pi as a server for a local database requires system configuration and optimization, as well as modifying the code of existing applications to allow them to interact directly with the local database. It will be necessary to examine best practices and known challenges in the hosting of databases and the development of web applications on embedded platforms such as the Raspberry Pi. This approach not only aims to reduce food waste but also seeks to provide a technologically innovative and sustainable solution to improve food management and distribution
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