This paper describes a system to remotely monitor and control complex stand-alone photovoltaic plants. In normal conditions the developed system registers and reports the overall performances; in case of incorrect behaviors it seasonably informs the operators. Moreover through appropriate instructions sent by users it allows to change the configurations of the plant and the settings of the measurement system as well. Several means of communications are available due to the need to adapt the system to the different operative conditions. However for a more general and flexible implementation,...
In our paper we present a laboratory temperature measuring system that can be remotely accessed by Internet. The system is based on the DS18B20 and DS1822 digital temperature sensors controlled with the aid of a microcontroller board PCB80c552. The system is used to measure and monitor the temperature in different places inside a computer. Using a web browser we can remotely configure the operating mode of each temperature sensor as well as we can read measured temperature in each measuring point. Using this system student can learn: use of integrated temperature sensors, software...
In this paper we describe the design of digital architectures suitable for the implementation of measurement data classification based on Support Vector Machines (SVMs). The performance of such architectures are then analyzed. The proposed approach can be applied for solving identification and inverse modelling problems, and for processing complex measurement data. Two very different case studies where real-time processing is of paramount importance are discussed: a nonlinear channel equalization and a high energy physics classification task.
The paper deals with the problem of pointing out and then measuring the manufacturing defects (scratches and halos) of handmade satin glasses by an accurate, real-time and cheap method. A wavelet-based de-noising technique is used to obtain surface information about glasses under inspection. The proposed algorithm first obtains a two-dimensional wavelet transform of a high resolution image of the glass under inspection which, according to multi-resolution analysis, produces a suitable number of decomposition levels of the image, and then it carries out a thresholding operation on details....
Measuring procedures in some cases require connection of two measuring objects or parts of equipment which terminals should not have common potential. Achievement of these requirements is inappropriate by using the transformer coupling because of its non-linear transfer function. Optical transfer of digital signals by using optocoupler provides the precision and stability needed to accurately signal monitoring.
Presented paper describes design, implementation and first results of the fully digital fluxgate magnetometer. The magnetometer operates in feedback configuration and uses fully digital signal detection realized in the digital signal processor (DSP). The magnetometer has measuring range ±100 μT, the linearity error is less than 40 ppm of FSR, noise 1.08 nT RMS /√Hz@1Hz and the frequency range of measured magnetic field is 15 Hz.
Symbolic Sensors can answer a query by a qualitative answer, using linguistic symbols instead of the usual numerical representation. Because there are no sensors with a built-in symbolic behaviour, the solution is to develop add-on modules for enhancing common sensors with such a set of features. These add-ons can be built either in software or in hardware. This paper focuses on the hardware solution and it aims to solve the lack of flexibility issue by using reconfigurable devices such as FPGAs. These devices allow dynamic reconfiguration and they provide the required flexibility for the...
In the following a device for automated polarity reversal and acquisition of the environmental parameters that affect the output voltage of a zener reference standard is described. The reversal is made with a mechanical switch whose thermal emfs are a few nanovolt. The alignment of the switch is supervised by a microprocessor that controls an electrical motor and identifies the switch position by means of angular and axial sensors. The microprocessor is also connected to ADCs and humidity and temperature sensor, and is capable of communicating with a PC, providing thorough information about...
Paper deals with measurement of polarization properties of fibers in variable thermal field. Study of polarization is important from the polarization dispersion point of view for communication systems and also in the area of interferometric and polarization sensors or general interferometric measurements. Our contribution solves a temperature dependence of polarization in a relatively short part of different types of fibers, where additionally fluctuation of power between both polarization modes could affect. These results can be interesting in the application of fibers in distributed...