1,111 research outputs found
An Ultrasonic Sensor for Distance Measurement in Automotive Applications
This paper describes an ultrasonic sensor that is able to measure the distance from the ground of selected points of a motor vehicle. The sensor is based on the measurement of the time of flight of an ultrasonic pulse, which is reflected by the ground. A constrained optimization technique is employed to obtain reflected pulses that are easily detectable by means of a threshold comparator. Such a technique, which takes the frequency response of the ultrasonic transducers into account, allows a sub-wavelength detection to be obtained. Experimental tests, performed with a 40 kHz piezoelectric-transducer based sensor, showed a standard uncertainty of 1 mm at rest or at low speeds; the sensor still works at speeds of up to 30 m/s, although at higher uncertainty. The sensor is composed of only low cost components, thus being apt for first car equipment in many cases, and is able to self-adapt to different conditions in order to give the best result
Contactless and absolute linear displacement detection based upon 3D printed magnets combined with passive radio-frequency identification
Within this work a passive and wireless magnetic sensor, to monitor linear
displacements is proposed. We exploit recent advances in 3D printing and
fabricate a polymer bonded magnet with a spatially linear magnetic field
component corresponding to the length of the magnet. Regulating the magnetic
compound fraction during printing allows specific shaping of the magnetic field
distribution. A giant magnetoresistance magnetic field sensor is combined with
a radio-frequency identification tag in order to passively monitor the exerted
magnetic field of the printed magnet. Due to the tailored magnetic field, a
displacement of the magnet with respect to the sensor can be detected within
the sub-mm regime. The sensor design provides good flexibility by controlling
the 3D printing process according to application needs. Absolute displacement
detection using low cost components and providing passive operation, long term
stability and longevity renders the proposed sensor system ideal for structural
health monitoring applications.Comment: 4 pages, 5 figures, 1 tabl
Eddy current based, contactless position transducer for a gas handle
In electric vehicles, it is normal to have an electronic set value for 'gas' and for 'brake'. Traditional potentiometers with sliding contacts are not reliable. Magnetoresistive sensors or hall effect sensors need a magnet on the moving part. The proposed sensor just needs iron on the moving part. It uses an oscillator circuit where the absorbed current is an indication of damping, so how close the iron is to the sensor. The component cost is low and the output has a soft gradual change with the displacement
Special asynchronous dynamometer designed for fast transient phenomena
This paper is focused on measurement of output of the rotary electromechanic machines, i.e. torque and speed.
Special attention is paid to the torque measurement under transient phenomena. The paper is also concentrated on the
optimization and interference of the designed asynchronous dynamometer. Thanks to the dynamometer it is possible to
measure very fast transient phenomena with a very high precision. The mathematical model of the asynchronous machine
completed with the mathematical description of the mechanical elements has also been added. Part of this work is focused on
parameters identification of the modeled mechanical elements. Selected transient states were simulated with the help of
MATLAB and SIMULINK language
Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: Demonstrations with a passive wireless acoustic delay line probe and vision
International audienceVibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates
An investigation of planar array system artefacts generated within an electrical impedance mammography system developed for breast cancer detection
An Electrical Impedance Mammography (EIM) planar array imaging system is being developed at the University of Sussex for the detection of breast cancers. Investigations have shown that during data collection, systematic errors and patient artefacts are frequently introduced during signal acquisition from different electrodes pairs. This is caused, in particular, by the large variations in the electrode-skin contact interface conditions occurring between separate electrode positions both with the same and different patients. As a result, the EIM image quality is seriously affected by these errors. Hence, this research aims to experimentally identify, analyse and propose effective methods to reduce the systematic errors at the electrode-skin interface. Experimental studies and subsequent analysis is presented to determine what ratio of electrode blockage seriously affects the acquired raw data which may in turn compromise the reconstruction. This leads to techniques for the fast and accurate detection of any such occurrences. These methodologies can be applied to any planar array based EIM system
A Review of Implementing ADC in RFID Sensor
The general considerations to design a sensor interface for passive RFID tags are discussed. This way, power and timing constraints imposed by ISO/IEC 15693 and ISO/IEC 14443 standards to HF RFID tags are explored. A generic multisensor interface is proposed and a survey analysis on the most suitable analog-to-digital converters for passive RFID sensing applications is reported. The most appropriate converter type and architecture are suggested. At the end, a specific sensor interface for carbon nanotube gas sensors is proposed and a brief discussion about its implemented circuits and preliminary results is made
A Review Of Implementing Adc In Rfid Sensor
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The general considerations to design a sensor interface for passive RFID tags are discussed. This way, power and timing constraints imposed by ISO/IEC 15693 and ISO/IEC 14443 standards to HF RFID tags are explored. A generic multisensor interface is proposed and a survey analysis on the most suitable analog-to-digital converters for passive RFID sensing applications is reported. The most appropriate converter type and architecture are suggested. At the end, a specific sensor interface for carbon nanotube gas sensors is proposed and a brief discussion about its implemented circuits and preliminary results is made.Region Rhone-Alpes (France)CNPq (Brazil)INCT/NAMITEC (Brazil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
A Review Of Implementing Adc In Rfid Sensor
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The general considerations to design a sensor interface for passive RFID tags are discussed. This way, power and timing constraints imposed by ISO/IEC 15693 and ISO/IEC 14443 standards to HF RFID tags are explored. A generic multisensor interface is proposed and a survey analysis on the most suitable analog-to-digital converters for passive RFID sensing applications is reported. The most appropriate converter type and architecture are suggested. At the end, a specific sensor interface for carbon nanotube gas sensors is proposed and a brief discussion about its implemented circuits and preliminary results is made.Region Rhone-Alpes (France)CNPq (Brazil)INCT/NAMITEC (Brazil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
An alternative to the band saw wheel wear measurement
There exist various methods how to measure the band saw wheel wear. Our article describes an alternative to the existing ones. To give an idea about that problem, we first describe the band saw components in general, and we are also summing up nowadays measurement methods. In contrast to them, we present our alternative solution based on laser sensors. The article contains the design realization example and the functional description of related application software. The testing measurement data illustrates our solution achievement. Our design benefits highlights are formulated as well. © 2018, World Scientific and Engineering Academy and Society. All rights reserved
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