Search results for "Instrumentation"
showing 10 items of 4914 documents
3D image acquisition system based on shape from focus technique
2013
agent Agrosup Dijon de l'UMREcolDurGEAPSI; This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed of randomly distributed objects with spatial discontinuities. In agronomic sciences, the 3D acquisition of natural scene is difficult due to the complex nature of the scenes. Our system is based on the Shape from Focus technique initially used in the microscopic domain. We propose to adapt this technique to the macroscopic domain and we detail the system as well as the image processing used to perform such technique. The Shape from Focus technique is a monocular and passive 3D acquisition method that resolves the occlusion problem affecting…
A Multi-Position Calibration Method for Consumer-Grade Accelerometers, Gyroscopes, and Magnetometers to Field Conditions
2017
This paper presents a calibration method for consumer-grade accelerometers, gyroscopes, and magnetometers. Considering the calibration of consumer-grade sensors, it is essential that no specialized equipment is required to create reference signals. In addition, the less is required from the reference signals, the more suitable the method is on the field. In the proposed method, the novelty in the calibration of the gyroscopes lies in the exploitation of only the known net rotations between the positions in a multi-position calibration. For accelerometers and magnetometers, the innovation is that the direction of reference signals, the gravity and the magnetic field of the Earth, are estimat…
A Novel Method of Distance Measurement Based on Pulse Position Modulation and Synchronization of Chaotic Signals Using Ultrasonic Radar Systems
2009
This paper deals with a novel method of transmission and receipt of a signal based on both the property of two chaotic systems generating the same chaotic signal when they are synchronized and the property of pulse position modulation (PPM) to be insensitive to the distortions of the transmission channel. The method is discussed in the context of ultrasonic radar systems, in which the transmitter and receiver, which consist of ultrasonic sensors, are near each other, and the received signal consists of the transmitted signal reflected by an obstacle. A reference sinusoidal signal is superimposed to a chaotic signal generated by a master chaotic system, and the whole signal is modulated acco…
Arc Fault Detection Method Based on CZT Low-Frequency Harmonic Current Analysis
2017
This paper presents a method for the detection of series arc faults in electrical circuits, which has been developed starting from an experimental characterization of the arc fault phenomenon and an arcing current study in several test conditions. Starting from this, the authors have found that is it possible to suitably detect arc faults by means of a high-resolution low-frequency harmonic analysis of current signal, based on chirp zeta transform, and a proper set of indicators. The proposed method effectiveness is shown by means of experimental tests, which were carried in both arcing and nonarcing conditions and in the presence of different loads, chosen according to the UL 1699 standard…
A Wireless Acoustic Array System for Binaural Loudness Evaluation in Cities
2017
Networks of acoustic sensors are being deployed in smart cities to continuously monitor noise levels. In this paper, a novel acoustic sensor device is designed for binaural loudness evaluation, in a standalone platform. The audio is acquired from an array of microphones and a binaural signal is synthesized by a direction-of-arrival algorithm and a head-related transfer function. Hardware setup and software algorithms are presented and the results are discussed. Finally, the tests conducted in an early deployment show the feasibility of using the device to carry out large temporal and spatial sampling for the evaluation of binaural loudness.
Design and experimental verification of a smart sensor to measure the energy and power consumption in a one-phase AC line
2009
Abstract A mixed electronic system has been designed to measure the active, apparent and reactive energies delivered to a load in a single-phase AC voltage line. For this purpose a smart sensor (ADE7753 from Analog Devices) was used. A magnetoresistance sensor is used as a current transducer and it is constant current biased by a generalized impedance converter. The magnetoresistance sensor technology provides direct isolation from the mains voltage and ferrite cores are not needed like Hall counterparts. All the measurements provided by the ADE7753 are read through the parallel port of the computer using a LabView application, which will process and present the readings to the user.
Charge measurement using an array of Faraday’s Cups on a printed circuit board
2014
Abstract An absolute method of measuring charge is to use a Faraday Cup (FC) principle. This study relates to a novel method of measuring charge on a flat substrate, which is coated with charged powder particles. The substrate consists of an array of FC with different dimensions. The sensor is manufactured using flame-retardant printed circuit board (PCB) technology. The objective of this work is to reduce the charge sharing by developing a grounded shield cup around each conductive cup in the array and accordingly increase cup-to-ground capacitance. The results have confirmed that the improved well shielding would provide a more accurate quantitative charge measurement.
A PC-based instrument for harmonics and interharmonics measurement in power supply systems
2004
Abstract Growing interest on power quality has led international working groups to define new standards for testing and measurement techniques to apply to power systems. Special attention has been paid to harmonic and interharmonic measurements. Here, the authors introduce a PC-based instrument capable of synchronising sampling frequency with fundamental frequency in order to perform on-line voltage or current distortion analysis. The instrument has been developed in accordance with currently available standards and international documents, IEC 61000-4-7 Ed. 2002, IEC 61000-4-30 Ed. 2003, Draft Guide IEEE P1159.1 Ed. 2003 and limits given by IEC 61000 Part. 3. A detailed description of the …
Instrumentation und Nachweisvermögen oberwellenpolarographischer Analysenverfahren
1978
Der Einflus der Instrumentation der einzelnen Baugruppen eines Oberwellenpolarographen auf das Nachweisvermogen der Gesamtmeseinrichtung wird untersucht. Der Gesamtaufbau eines solchen Polarographen wird beschrieben.
VISUALIZATION IN ASTRONOMY AT GENERAL SCHOOL
2009
This is an International Year of Astronomy (IYA 2009) when we pay great attention to astronomy education. The International Year of Astronomy is a year-long celebration of astronomy, taking place in 2009 to coincide with the 400th anniversary of the first recorded astronomical observations with a telescope by Galileo Galilei. Author presents a modern approach to teaching astronomy and planetary sciences, centered on visual images and simulations of planetary objects. The basic idea is to take the students to other celestial objects as tourists, and to teach science through the observations of various natural phenomena in these new environments. The power of scientific visualization, through…