Search results for " Sensor."
showing 10 items of 1700 documents
Magnetic Tunnel Junction (MTJ) Sensors for Integrated Circuits (IC) Electric Current Measurement
2013
We report on MgO Magnetic Tunnel Junction (MTJ) devices focusing on their potential application in the measurement of electrical current at the integrated circuit level. Single devices and full bridges have been specifically developed for this purpose. A sort of different designs regarding their geometry arrangement as well as the number of constitutive elements have been tested. Experimental characterization has been performed and results including impedance and sensitivity measurements are given.
Automated single ring infiltrometer with a low-cost microcontroller circuit
2015
Automation of a new single ring infiltrometer.Data acquisition system based on the open source microcontroller platform Arduino.New method to minimize the disturbance of the soil surface.New approach to process transducer output. A method to automate data collection with a compact infiltrometer under constant head conditions was developed. The infiltrometer consists of a containment ring with a small quasi-constant head of water (i.e., 2-3mm) that is controlled by a Mariotte reservoir and a data acquisition system based on the open source microcontroller platform Arduino and a differential pressure transducer. The presented design can be easily reproduced and operated.The infiltrometer was …
Laser-air hybrid ultrasonic technique for dynamic railroad inspection applications
2005
The Laser-Air Hybrid Ultrasonic Technique (LAHUT) combines laser generation with air-coupled detection of ultrasound. The technique is non-contact and has the characteristic of operating from remote distances. Acoustic wave laser-generation apparatus can be metres away from the interrogated surface, while air-coupled detection stand-off can be on the order of several centimetres. The technique has the unique capability of interrogating structural materials in their true industrial environment. Dynamic tests are performed on parts with complex geometry, limited accessibility and curved surfaces. Also, dark and rough finish surfaces, which significantly reduce the efficiency of optical detect…
Proof of concept of wayside railroad wheel inspection using a laser-air hybrid ultrasonic technique
2003
Non-destructive inspection of railroad wheels is performed in maintenance shops, where wheels are removed and inspected individually. No technique is yet available to the railroad industry to perform wayside inspections of wheels on a moving train. The characteristics of laser and air-coupled ultrasound are discussed to justify the use of a laser-air hybrid ultrasonic technique. Laser generation of ultrasound is combined with air-coupled detection to provide a flexible non-contact and remote technique that would enable the railroad industry to perform wayside inspections of moving railroad wheels. The present paper describes Proof of Concept set-up and results of the experiments performed a…
Implementation of a Drosophila-inspired orientation model on the Eye-Ris platform
2010
A behavioral model, recently derived from experiments on fruit-flies, was implemented, with successful comparative experiments on orientation control in real robots. This model has been firstly implemented in a standard CNN structure, using an algorithm based on classical, space-invariant templates. Subsequently, the Eye-Ris platform was utilised for the implementation of the whole strategy, at the aim to constitute a stand alone smart sensor for orientation control in bio-inspired robotic platforms. The Eye-Ris vl.2 is a visual system, made by Anafocus, that employs a fully-parallel mixed-signal array sensor-processor chip. Some experiments are reported using a commercial roving platform, …
Designing an open source maintenance-free Environmental Monitoring Application for Wireless Sensor Networks
2015
We discuss the analysis and design of an Environmental Monitoring Application.The application is reliable and maintenance-free, runs in multihop wireless network.We analyze the different alternatives and tradeoffs, using open source software.The application is validated in long-term outdoor deployments with good results.Related work does not analyze the software design with open source. We discuss the entire process for the analysis and design of an Environmental Monitoring Application for Wireless Sensor Networks, using existing open source components to create the application. We provide a thorough study of the different alternatives, from the selection of the embedded operating system to…
Fuzzy Data Fusion for Real-World Mapping Using 360° Rotating Ultrasonic Sensor
1997
Abstract Mobile robot perception of the external environment is limited by the features of the used sensor. An useful technique used to improve robot perception is data fusion. This paper presents an approach to build a map of an unknown environment applying fuzzy data fusion methods to data acquired through an ultrasonic sensor. Conditioning of these data and motion control of the mobil robot by fuzzy data fusion are also described. The resulting two dimensional map is used for path planning and navigation. The proposed approach is exrperimentally tested using real distance measures acquired by a 360° rotating sensor.
Integration and application of emerging RF systems formed by wireless sensor networks: exhaustive experiment to their implantation in different envir…
2007
This paper shows the possibility to use Bluetooth for wireless short range communication in an industrial environment. Traditionally many types of devices have been delivered as mechanical devices and more or less all or the intelligence and control has been added. Nowadays there is a growing trend towards a higher level of built-in intelligence in the devices, constituting the intelligent nodes. This type of systems allows the implementation of highly flexible control systems capable of adapting themselves to different situations. With the introduction of RF systems, another dimension is aggregated, the possibility to wirelessly connect to the devices. The technology makes it possible to e…
Low-Cost Alternatives for Urban Noise Nuisance Monitoring Using Wireless Sensor Networks
2015
Noise pollution caused by vehicular traffic is a common problem in urban environments that has been shown to affect people's health and children's cognition. In the last decade, several studies have been conducted to assess this noise, by measuring the equivalent noise pressure level (called L eq ) to acquire an accurate sound map using wireless networks with acoustic sensors. However, even with similar values of L eq , people can feel the noise differently according to its frequency characteristics. Thus, indexes, which can express people's feelings by subjective measures, are required. In this paper, we analyze the suitability of using the psychoacoustic metrics given by the Zwicker's mod…
Decentralized Synchronization for Zigbee wireless sensor networks in Multi-Hop Topology
2010
Abstract The most effective solution for energy saving in low-rate wireless sensor networks is maintaining each node in a doze state as long as possible. In order to guarantee network connectivity, the intervals at which the network sensors are turned on and off have to be coordinated. We analyze the Zigbee MAC performance in sensor networks deployed in multi-hop topologies. For this networks, critical inefficiencies can arise due to transmissions performed by hidden nodes. We evaluate the impact of different synchronization schemes on the network performance, both in terms of network capacity and in terms of energy consumption. We show how the synchronization function can be opportunistica…