24 research outputs found

    Test platform for electronic control units of high-performance safety-critical multi actuator systems

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    In this paper we are mostly concerned with the problem of testing electronic control units of synchronized electric power actuators. This task is particularly complex for safety critical applications, where it is crucial that the control system properly reacts in response to the faults, that are hard to reproduce and verify. A cost-effective flexible and reconfigurable test platform is proposed, discussing its architecture and implementation. The proposed system facilitates the phase of definition and development of the electronic control unit, allowing the interfacing towards both hydraulic and electromechanical actuators, and having a high flexibility as regards the I/O signals. Some results, obtained during the laboratory test activity, are also presented

    A Web Service Interface for a Distributed Measurement System Based on Decentralized Sharing Network 1

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    Abstract: The Web Service technology has increased in importance in these years. Accessing to remote resources without knowledge about physical implementation and with a reduced hardware requirement is the main goal of new portable device. The use of Web Service technology allows clients to create a standard interface to access to the measurement service published by the server. In low cost multipoint distributed measurement systems, the measurement services are provided by Smart Web Sensors. A new concept of distributed measurement system arises from the possibility to fuse all services with the same functionality in a single user-transparent service: the response of distributed services network to a user request gives a complete vision of the service by collecting results from any Smart Web Sensor in the network. So, in this paper the development of a multipoint distributed measurement system, based on the peer-to-peer Gnutella network with Web Service interface, is presented. Copyright © 2013 IFSA

    Measurements for non-intrusive load monitoring through machine learning approaches

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    The topic of non-intrusive load monitoring (NILM) has seen a significant increase in research interest over the past decade, which has led to a significant increase in the performance of these systems. Nowadays, NILM systems are used in numerous applications, in particular by energy companies that provide users with an advanced management service of different consumption. These systems are mainly based on artificial intelligence algorithms that allow the disaggregation of energy by processing the absorbed power signal over more or less long time intervals (generally from fractions of an hour up to 24 h). Less attention was paid to the search for solutions that allow non-intrusive monitoring of the load in (almost) real time, that is, systems that make it possible to determine the variations in loads in extremely short times (seconds or fractions of a second). This paper proposes possible approaches for non-intrusive load monitoring systems operating in real time, analysing them from the point of view of measurement. The measurement and post-processing techniques used are illustrated and the results discussed. In addition, the work discusses the use of the results obtained to train machine learning algorithms that allow you to convert the measurement results into useful information for the user

    Conjugates between minor groove binders and Zn(II)-tach complexes: Synthesis, characterization, and interaction with plasmid DNA

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    A new family of conjugates between a Zn(II)-tach complex and (indole)(2) or benzofuran-indole amide minor groove binders connected through alkyl or oxyethyl linkers of different lengths has been prepared. The conjugates bind strongly to DNA. However, the complexation to DNA to promote the Zn(II) catalyzed hydrolytic cleavage of the DNA results instead in its inhibition. This inhibition effect has been confirmed also using Cu(II). Modeling studies suggest that in the most stable complex conformation, the minor groove binder and the linker lie in the minor groove hampering the interaction between the metal complex and the phosphate backbone of DNA. Therefore, the linear arrangement of minor groove binder-linker-metal complex appears to be effective to ensure tight binding but unproductive from a hydrolytic point of view. (C) 2017 Elsevier Ltd. All rights reserved

    Measuring system for microelectric power

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    In this paper, we are mostly concerned with the measurement of electric micropower and energy. This parameter is essential to evaluate the energy efficiency of low power devices, such as wireless operated monitoring and control systems. It is also important to measure the standby power consumed by appliances and equipment while switched off. The measurement of power generated by the harvesting systems is another field of application. Thus, it is important to implement the power meters to accurately measure power . The common commercially available wattmeters are inaccurate for these low-power measurements for two main reasons: a limitation on the instrument dynamic range and the intermittent operating mode of some devices. Particularly critical is the current measurement, for the high gains required in most applications. In this paper, a measuring system for microelectric power and energy is proposed. It operates for voltage up to 3 Vpp and current from 1 pA to 5 mA, corresponding to an electric power down to around a fraction of microwatt. In the following, the system architecture is described, also discussing some experimental results obtained during the characterization test

    Survey about Classical and Innovative Definitions of the Power Quantities Under Nonsinusoidal Conditions

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    AbstractToday, electric power and energy measurements are widely required, practically in all the research, industrial and consumer applications. Power measurements are of importance primarily for the test, monitoring and maintenance of energy supply networks and electric equipment. The measurement of both electric power and energy is a still open research problem in the electrical engineering community. Phenomena like harmonic distortion, noise, transients, over-voltages and voltage dips have increased the difficulty in achieving accurate measurements, compared with the case of sinusoidal signals. Many of the non-active power component definitions that have been proposed cannot be implemented in the traditional electro-mechanical or solid-state meters, but require the adoption of more expensive and time-consuming digital techniques; recently, some new approaches for the definition of power quantities have been investigated. In this paper, a survey of the classical and innovative definitions is proposed, with the aim of summarize the different points of view outlined by the researchers. A case study of power factor correction in nonsinusoidal conditions is also presented, to give a numerical comparison about the power quantities measured according to the various approaches

    Thermographic and electrical characterization of a photovoltaic panel under partial shading conditions: a case study

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    Shading is one of the most critical factors that produces a reduction in power in photovoltaic (PV) modules. The main causes of shading are related to cloud cover; local specificity; natural characteristics; building and other civil works; and the presence of the PV system itself. A reduction in overall radiation produces a consequent reduction in electric power. Another more problematic effect is associated with the partial shading of the PV modules. The shaded cell behaves as a load, dissipating energy and increasing its temperature. This effect can involve irreversible changes to the PV module, with a decrease in performance that can even cause the destruction of the shaded cell.The main aim of this work is the development of a testing procedure for the performance evaluation of commercial PV modules in the presence of partial shading on one cell. Tests were carried out using thermographic and electric measurements and by varying the shading levels according to IEC standards. Shading up to total darkening is achieved by means of a number of filters that reduce the direct solar irradiance.As a case study, a complete characterisation of a 180 Wp polycrystalline PV module was performed according to the proposed testing procedure, showing that high temperatures can be measured on the shaded PV module surface even if only 50 % of the surface of one cell of the PV module is darkened.</p
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