112,258 research outputs found
IEEE 1451: Communication among smart sensors using MQTT protocol
No full textSmart sensors, transducers, and sensor networks are undergoing, in recent years, a profound transformation thanks to the spread of new communication protocols based on the Producer-Consumer paradigm rather than on the Request-Response paradigm of Server-Client architectures. In this context, the substandard IEEE 1451.1.6 has been introduced in the IEEE 1451 standard, which aims to standardize the Producer-Consumer based communication protocols, particularly MQTT. The role of this standard is fundamental for the realization of sensor networks with nodes produced by different manufacturers and integrated in a fully automatic way according to the paradigm 'Plug and Play'. This work aims to verify the progress of this sub-standard by testing its reliability with the development and testing of a prototype wireless sensor network based on MQTT with low-cost hardware. The prototype will consist of a Network Capable Application Processor (NCAP) node and a Transducer Interface Module (TIM) node, while the role of MQTT Broker and Wi-Fi Access Point for the physical layer of the Wireless Sensor Network will be covered by the NCAP itself
Designing low-cost modified cladding sensors: A structured approach
No full textIn this paper, a novel solution for signal conditioning, fiber illumination, and measurement is proposed for an optical fiber sensor based on a modified cladding sensing element. The presented technique has properties of compactness and low cost, due to the use of very common optoelectronic components, and flexibility, since it could be employed for different kinds of optical fiber sensors. In particular, a prototype has been realized and characterized for the measurement of liquid temperature
Preliminary Study on the Quality of Distributed Calibration Procedures for WSN
No full textNowadays, Wireless Sensor Networks are being used more and more widely. These are used to monitor various parameters, providing spatial and temporal information that cannot be obtained by using a single sensor node. Given the complexity of measurement, it is difficult to perform a spatially and temporally accurate calibration. One of the most widely used solutions is to include in WSNs some reference sensors with excellent metrological performance, which, however, has as its downside a high cost. The distributed calibration procedure, on the other hand, is based on periodic recalibration of sensor nodes with a single reference sensor. This paper will present a preliminary study on the inaccuracies and sources of uncertainty of this method and possible strategies for improving the quality of this technique by optimizing the placement of the reference sensor and the measurement time for calibration
Development of a new speed measurement technique based on deep learning
No full textThe more pervasive use of Artificial Intelligence (AI) has enabled feature extraction enhancement in several fields, particularly in image processing applications. Thanks to AI, it is possible to use low-cost devices (e.g., webcams and surveillance cameras in complex scenarios) like vehicle speed measurement, obtaining a significant reduction of instrument costs and a great spread of their use. The paper presents a new industrial measurement instrument for vehicle speed based on non-dedicated hardware devices and innovative image processing methods like Regional CNN (Convolutional Neural Network). The proposed hardware is based on a generic surveillance camera or even a simple webcam and an R-CNN to transform it into an intelligent tool capable of estimating the speed of a vehicle and tracking its movement under controlled conditions. One of the essential aspects of the work concerns the metrological characterization of the proposed method. Measurement uncertainty has been evaluated. The metrological characterization of approaches using artificial intelligence can be fundamental for spreading such technologies in practical scenarios and impulse the industrial development of enhanced tools that can comply with legal regulations for speed measurement. The measured velocities of a car under test have been compared with a reference constituted by the vehicle speed retrieved by the ABS ECU
Smart Sensor Efficient Signal Processing for Earthquake Early Detection
No full textThis paper presents a new method for earthquake early warning alert that uses a smart sampling technique that expose the signal information in a way that it is simpler to infer knowledge. The objective is to estimate, from the first few seconds of the P wave, if the incoming earthquake is destructive or not. The proposed method is described and compared to conventional approaches. Performance results for real seismic data are shown highlighting the results for earthquakes of different magnitudes. Preliminary results are excellent for inferring damage based on the approach of a single seismic station
High-resolution geological model of the gravitational deformation affecting the western slope of Mt. Epomeo (Ischia)
No full textThe recent geological history of Ischia Island is characterized by slope-scale gravitational deformations closely related to volcano-tectonic dynamics of the Mt. Epomeo resurgent caldera. This study focuses on the gravitational deformation that involves alkali-trachytic lava and trachytic ignimbrite flow-units of Mt. Nuovo, located in the western portion of Mt. Epomeo. A preliminary, high-resolution engineering-geological model was obtained through geological, geomorphological and geophysical surveys and reveals a complex morpho-structure with geomorphological evidence of gravitational instability. The complexity of the ongoing slope deformations is confirmed by field geo-structural evidences that led to the identification of a multiple compound mechanism with a main rupture surface which is about 200 m deep. This geometry was better constrained by passive seismic investigations consisting in noise measurements, focused on resonance frequencies of the soil (i.e. based on H/V Nakamura approach). In addition, a close relationship between the outcrop of Mt. Epomeo Green Tuff breccia layers and the distribution of hydrothermal emissions and gas vent can be inferred, as it is related to the higher permeability of the breccia layers with respect to the main Mt. Epomeo Green Tuff flow unit, where the ascent path of deep hydrothermal fluids developed along faults and fracture networks. © Società Geologica Italiana, Roma 2015
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