Ultrasonic Receiver Research Articles

A new approach in physical modeling for velocity anisotropy study

Special automated equipment is constructed for ultrasonic velocity measurements at various incidence angles of waves that is necessary for estimation of anisotropy parameters of rocks. The equipment includes hydraulic press for simulation of vertical pressure in the Earth, at a range up to 40 MPa and computer controlled positioning system that provides precise independent positioning of ultrasonic source and receiver. This setup enables us to perform reliable velocity measurements at the angle interval from 15° to 90° and additional single measurement at 0°. The minimum step of a transducer position in 15°-90° range is 8.1'. As an example on anisotropy study, we perform physical modeling of wave propagation in artificial sample of transversely isotropic (TI) symmetry, which represents a model of fractured rock. Using experimental setup, we acquire P-wave velocity data for plate-stack model with vertical axis of symmetry formed by acrylic 1 mm thick sheet plates. Using measured velocities, we estimate Thomsen’s anisotropy parameters e and δ, and get dependence between the velocity of P-waves and symmetry axis of the model. . In our oncoming research, the upgraded Ultrasonic Measuring System will be supplemented by multicomponent transducers similar to those described in Chichinina et al. (2009), which allow simultaneous recording of P, SV and SH waves at each data point.

Non-Contact Ultrasonic Inspection of Impact Damage in Composite Laminates by Visualization of Lamb wave Propagation

This study demonstrates a rapid non-contact ultrasonic inspection technique by visualization of Lamb wave propagation for detecting impact damage in carbon fiber reinforced polymer (CFRP) laminates. We have developed an optimized laser ultrasonic imaging system, which consists of a rapid pulsed laser scanning unit for ultrasonic generation and a laser Doppler vibrometer (LDV) unit for ultrasonic reception. CFRP laminates were subjected to low-velocity impact to introduce barely visible impact damage. In order to improve the signal-to-noise ratio of the detected ultrasonic signal, retroreflective tape and a signal averaging process were used. We thus successfully visualized the propagation of the pulsed Lamb A0 mode in the CFRP laminates without contact. Interactions between the Lamb waves and impact damage were clearly observed and the damage was easily detected through the change in wave propagation. Furthermore, we demonstrated that the damage could be rapidly detected without signal averaging. This method has significant advantages in detecting damage compared to the conventional method using a contact resonant ultrasonic transducer due to the absence of the ringing phenomenon when using the LDV.

초음파 센서의 혼 가이드에 의한 음향 수신 특성

This study addresses the acoustic reception characteristics of a horn guide applied to an ultrasonic sensor for distance measurement. In order to design a horn guide to improve the acoustic directivity of ultrasonic sensors for both transmission and reception, identifying the reception performance as well as the transmission directivity of the ultrasound is necessary. The purpose of this study was to find the horn guide angle maximizing the ultrasonic reception performance by comparing it according to the angle of the cone-shaped horn guide. Acoustic finite element analysis was performed to identify the ultrasonic reception performance depending on the horn guide angle. For the horn guide with a cone shape, acoustic analysis was performed after modeling horns of various angles in the range from 0° to 40° of the wall angle of the horn. Horn guides made using a 3D printer were attached to an ultrasonic sensor to measure the received sound pressure. From the experimental results, the validity of the finite element analysis results was verified. Analysis and experiment consistently showed that the maximum reception was observed at horn angles in the range from 20° to 25°.

Effect of Amplitude on Wave Propagation

It is common to use ultrasonic techniques to measure elastic properties of the porous media. However, conventional methods are unable to measure local strain in ultrasonic wave. This is not clear how the velocity of wave depends on its amplitude. In this work we, 1) measured the particle displacement in the ultrasonic wave using a Laser Doppler Interferometry (LDI) and 2) measured changes of P-wave velocities with wave amplitude for elastic (Aluminium), viscoelastic (Polymethylmethacrylate), and granular media (dried Gosford sandstone). We checked this phenomena using a conventional ultrasonic receiver and linked this changes to a local strain in wave. The study indicated that for a sandstone sample by increasing of local strain produced by an ultrasonic wave from 7*10-6 to 2*10-5 the P wave velocity increase by 0.7%. We also analysed the accuracy of velocity measured using LDI as a receiver and compare the results with that using conventional transducers. Moreover, the effect of proper couplant of the sample and the transducer was investigated in details.

A 6-bit digital CMOS variable gain attenuator with large dynamic range and high linearity-in-dB for ultrasound imaging applications

A 6-bit digital CMOS variable gain attenuator (VGAT) with 42 dB dynamic range (DR) and high linearity-in-dB was presented. CMOS transistors were used as the shunt devices and attenuation gains with different distribution rules of the shunt transistors (W/L)s were analyzed and simulated in detail. A geometric series with a length of 42 and a ratio of 1.122 was finally adopted for the (W/L)s to achieve the 42 dB DR and 1 dB attenuation step size. Fabricated in a 0.18-μm CMOS technology, the proposed VGAT had been integrated in a 4-channel ultrasonic imaging receiver chip and occupied an area of about 0.5 mm × 0.37 mm. The gain errors were limited in the range from −1 dB to −1.3 dB at 27 °C and the DR of the VGAT at different temperatures was retained above 40 dB. The –3 dB bandwidth was about 1.9 GHz at the maximum attenuation and the S11 was better than −11 dB with a 30 MHz input.

Ultrasonic localization method based on receiver array optimization schemes

Ultrasonic localization system using trilateration has been adopted in various types of full-enclosed and semi-enclosed space. For small-scale or enclosed scenarios, there is an important phenomenon, that is, the ultrasonic wave may rapidly reflect back and forth between the walls to form different normal waves during the process of propagation, which may break the inverse square law of sound intensity (the sound intensity in free space is inversely proportional to the square of the distance). The other problem is that the sound intensity of some local corner points are obviously stronger than those points near the acoustic source, which may confuse the ultrasonic receivers and bring significant differences in measurement errors. To avoid excessive errors influence for the positioning accuracy, in this article, a novel ultrasonic localization method based on receiver array optimization schemes is reported. The main purpose is to activate the ultrasonic receiver in the area as well as shield the ultrasonic receiver outside the area. The system error will be reduced based on this method, and most of the redundant data will be eliminated. The simulation results are visualized and compared with the existing methods. The positioning accuracy measured by our method is increased significantly.

Perancangan Alat Ukur Massa Jenis Zat Cair Menggunakan Cepat Rambat Gelombang Ultrasonik

Density is a measure of the mass of volume unity. How to measure density in general by measuring the weight and dividing it by the volume of liquid, so in this way the measurement is not. Measurement of the density of the liquid based on the ultrasonic velocity becomes an alternative so that the measurement can be done directly, accurately, practically, and easily.Ultrasonic velocity becomes the variable to determine the density of the liquid. Time synchronization begins when the ultrasonic transmitter emits ultrasonic and is terminated when the receiver receives ultrasonic. The discrete ultrasonic wave transmission method is performed when the ultrasonic receiver receives transmittance from the ultrasonic transmitter then the 40KHz signal pulse is stopped and ultrasonic transmission is repeated up to 10 times the measurement data.From this study obtained some conclusions. Ultrasonic velocity is influenced by the viscosity of the liquid, ultrasonic velocity through 1394m / s aquades, ultrasonic velocity through cooking oil 1387m / s, ultrasonic velocity through liquid soap 1175m / s, ultrasonic velocity through liquid soap solution 40% 1317m / s , Ultrasonic velocity through liquid soap solution 70% 1257m / s, velocity measurement deviation of 0.43% and 0.01% density calculation type.

텅스텐의 열충격 손상에 대한 초음파 특성 평가"

Tungsten is used as a high temperature component because it does not change its mechanical and physical properties even at high temperatures, and it is manufactured by sintering. However, it is hard to produce tungsten because of the high sintering temperature. One of objectives of this study is to lower the sintering temperature by using additives and pressure. The damage characteristics due to thermal shock on the tungsten produced by this liquid phase sintering method were evaluated using a nondestructive technique. By using the ultrasonic pulse receiver technique, the amplitude and attenuation coefficient of the ultrasonic wave were measured as the thermal shock cycle of the material was increased, and the relationship between the thermal shock cycle and the attenuation coefficient was analyzed. It has been found that the tungsten surface crack increases as the thermal shock cycle increases, and the attenuation coefficient increases linearly due to scattering of wave by increasing cracks.

Lossless and lossy modeling of ultrasonic imaging system for immersion applications: Simulation and experimentation

The design, modeling, optimization, and development of the entire ultrasonic imaging system is a complex task which involves an understanding of acoustic physics of transducer, acoustic properties of propagating medium, transmission cables and analog front-end electronics for generating and receiving of ultrasonic signals. Such immersion systems are extensively utilized in non-destructive testing (NDT) application for flaw detection, dimensional measurements, material characterization and many more. This paper presents the one-dimensional simulation modeling of the entire ultrasonic imaging system. For validation purpose, a single channel real-time ultrasonic imaging system has been designed and developed for laboratory application which contains high voltage ultrasonic spike pulser, high voltage protection circuits, ultrasonic receiver amplifiers, co-axial cables and an ultrasonic transducer. Lossless and lossy (low-loss) simulations have been performed for ultrasonic transducer and propagation medium using the transmission line model. Effects of non-ideal, frequency-dependent and non-linear components in high voltage excitation circuit (pulser), the receiver circuit and the effects of cables are also considered for modeling and simulation. Validation results of the entire ultrasonic imaging system provide very close agreement with lossy simulated results.

Design of Low-power Ultrasonic Anemometer Based on STM32L476

The power consumption of ultrasonic anemometers in engineering application has always been too high, which could limit their application in the long-time field measurement for wind speed. To solve the above problem, an ultrasonic anemometer with low power consumption, which employs the time-difference method to measure wind speed, has been designed in this paper. The ultra-low-power microprocessor STM32L476 is adopted as the core processor and low-power chips are used extensively in peripheral circuits. The whole circuit consists of power circuit, ultrasonic wave transmitter, signal receiver and memory chip. Besides, it can work in both online mode and self-contained mode. Simultaneously, Kalman filter algorithms have been employed to reduce data errors. It has been indicated in many experiments that the anemometer has lower power consumption, as well as higher precision.

Ultrasonic stent motor

The purpose of this study is to develop a stent motor for medical blood vessel treatment. The stent motor is a movable stent. It has functions of removing plaque and expanding blood vessels. It consists of two parts; ultrasonic receivers and vibration transmitting coil (stator). In this study, the authors have focused to the vibration analysis of the receiver. In the first design stage, the authors have evaluated resonant phenomenon using finite element method. When driving it in water, the resonant frequency of the air use is shifted due to mass effect of water around the receiver. The frequency analysis of the receiver shows that extremely high precision of dimensions is required because the resonant frequency in water depends not only the size but also the amplitude of the vibration. It is very difficult to design an optimal receiver resonating in water. In order to solve this problem, the authors have tried a new receiver with wide plate receiving ultrasound effectively and requiring no resonant. The authors have succeeded in driving this type of motor in water.

Accuracy on the Time-of-Flight Estimation for Ultrasonic Waves Applied to Non-Destructive Evaluation of Standing Trees: A Comparative Experimental Study

Time-of-flight measurement is a critical step to perform ultrasonic non-destructive testing of standing trees, with direct influence on the precision of defect detection. Aiming to increase the accuracy on the estimation, the characteristics of the ultrasonic measurement chain should be adapted to the constraints of wood testing in living condition. This study focused on the excitation signal parameters, such as shape, temporal duration, and frequency response, and then the selection of a suitable time-of-flight determination technique. A standing plane tree was tested, placing ultrasonic receivers at four different positions, with five different excitation signals and three time-of-flight detection methods. The proposed ultrasonic chain of measurement resulted in high signal-to-noise ratios in received signals for all configurations. A time-frequency analysis was used to determine the power distribution in the frequency domain, showing that only chirp signal could concentrate the power around the resonant frequency of the sensor. Threshold and Akaike information criterion method performed similar for impulsive signals with decreasing uncertainty as sensor position approached to the radial direction. Those two methods failed to accurate determine time-of-flight for Gaussian pulse and chirp signals. Cross-correlation was only suitable for the chirp signal, presenting the lower uncertainty values among all configurations.

Perancangan Flowmeter Ultrasonik untuk Mengukur Debit Air Pada Pipa

Measurement of water discharge using ultrasonic wave properties ensures the stability of measured water profile because of its non-intrusive nature. In this study, a water discharge measuring device has been developed by utilizing ultrasonic wave properties to determine its speed. The device is designed using two pairs of ultrasonic transmitters and receivers at upstream and downstream positions toward the direction of the water flow. 40 kHz ultrasonic waves are generated with AD9850 DDS sinusoidal pulse generating module. The sensor data processor uses an Arduino Due microcontroller module by calculating the measured ultrasonic wave travel time difference. Measurements were made on a 57 mm diameter pipe with flow rates varied using 25%, 50%, 75%, and 100% tap openings. The measurement resulte shows the lowest water debit calculation value of 4.42×10-4 m3/s at 25% faucet opening and highest discharge of 2.15×10-3 m3/s at 100% faucet opening with the values of coefficient of correlation and coefficient of determination on 25%, 50%, 75% and 100% faucet openings respectively 0.9715, 0.9669, 0.9604 and 0.9647 and 94.37%, 93.49%, 92 , 24%, and 93.07%.

Measurement of Pipe Strain Using an Ultrasonic System

Ultrasonic sensors can be used to measure strain occurring on an object. In this investigation, an ultrasonic signal utilized the reflected signal as a means of monitoring the condition of a pipe. This is an alternative to the strain gage which is commonly used but has a limited life span. The ultrasonic signal was transmitted to a specific location on the pipe, and then reflected by the pipe surface which experienced strain towards the ultrasonic receiver. Collimation of the transmitted and received signals is performed by aluminum probe cones attached to both ultrasonic transducers. Changes in the strain due to the pipe bending will result in changes in the electric signal due to the changes in the sound intensity. The received electric signal was processed by a signal conditioning circuit consisting of preamplifier, amplifier, band-pass filter and rectifier before being displayed. Two experiments were conducted to establish the relationship between strain on the pipe and the ultrasonic intensity. In order to verify the results, an experiment was conducted using a strain gage and the results were identical. The results show that the system is able to measure strain when the pipe bends.

공기 접촉식 초음파 수신을 통한 알루미늄 소재의 상대 비선형 측정

비선형 초음파는 재료의 손상 상태나 특성을 평가하기 위해 사용되고 있으며, 정량적인 측정 지표로서 절대비선형 파라미터(β)가 자주 사용되고 있다. 비선형 파라미터 측정값에 영향을 미치는 여러 가지 인자가운데서 수신탐촉자와 시편 사이에 접촉 압력을 일정하게 유지하는 일은 검사의 신뢰성과 반복성을 위해 중요하다. 기존의 접촉식 초음파 수신 과정을 개선하기 위한 방법으로서 공기접촉식 탐촉자의 사용이 대안이 될 수 있다. 본 연구에서는 먼저 회절 및 감쇠 보정을 적용한 상대비선형 파라미터(β′)를 정의하고, 참조시편에 대한 목표시편의 상대비선형 파라미터 비(β′/β′SUBref/SUB)는 절대비선형 파라미터 비(β′/β′SUBref/SUB)와 동일함을 입증하였다. 이렇게 함으로써 참조시편의 종류와 두께에 대한 제한이 완전히 없어지며, βref를 아는 경우 상대비선형 측정으로부터 목표시편의 β 측정이 가능하다. 시편과 공기로 이루어진 이중매질의 회절 및 감쇠 보정 식을 유도하고, 재료의 비선형 특성이 잘 알려진 세 가지 종류의 알루미늄 시편에 대하여 공기접촉식 탐촉자를 이용하여 β′을 각각 측정하였다. 임의의 참조시편을 사용하여 각 알루미늄 종류에 대해 측정한 β′/β′SUBref/SUB는 β/βSUBref/SUB와 7% 이내로 잘 일치하였다.

Improvement of distance measurement error by attenuation of ultrasonic transmitter and receiver signal for the ultrasonic positioning system

Improvement of distance measurement error by attenuation of ultrasonic transmitter and receiver signal for the ultrasonic positioning system

Cacna1c haploinsufficiency leads to pro-social 50-kHz ultrasonic communication deficits in rats.

ABSTRACTThe cross-disorder risk gene CACNA1C is strongly implicated in multiple neuropsychiatric disorders, including autism spectrum disorder (ASD), bipolar disorder (BPD) and schizophrenia (SCZ), with deficits in social functioning being common for all major neuropsychiatric disorders. In the present study, we explored the role of Cacna1c in regulating disorder-relevant behavioral phenotypes, focusing on socio-affective communication after weaning during the critical developmental period of adolescence in rats. To this aim, we used a newly developed genetic Cacna1c rat model and applied a truly reciprocal approach for studying communication through ultrasonic vocalizations, including both sender and receiver. Our results show that a deletion of Cacna1c leads to deficits in social behavior and pro-social 50-kHz ultrasonic communication in rats. Reduced levels of 50-kHz ultrasonic vocalizations emitted during rough-and-tumble play may suggest that Cacna1c haploinsufficient rats derive less reward from playful social interactions. Besides the emission of fewer 50-kHz ultrasonic vocalizations in the sender, Cacna1c deletion reduced social approach behavior elicited by playback of 50-kHz ultrasonic vocalizations. This indicates that Cacna1c haploinsufficiency has detrimental effects on 50-kHz ultrasonic communication in both sender and receiver. Together, these data suggest that Cacna1c plays a prominent role in regulating socio-affective communication in rats with relevance for ASD, BPD and SCZ.This article has an associated First Person interview with the first author of the paper.

Phased Array Focusing for Acoustic Wireless Power Transfer.

Wireless power transfer (WPT) through acoustic waves can achieve higher efficiencies than inductive coupling when the distance is above several times the transducer size. This paper demonstrates the use of ultrasonic phased arrays to focus power to receivers at arbitrary locations to increase the power transfer efficiency. Using a phased array consisting of 37 elements at a distance nearly 5 times the receiver transducer diameter, a factor of 2.6 increase in efficiency was achieved when compared to a case equivalent to a single large transducer with the same peak efficiency distance. The array has a total diameter of 7 cm, and transmits through air at 40 kHz to a 1.1-cm diameter receiver, achieving a peak overall efficiency of 4% at a distance of 5 cm. By adjusting the focal distance, the efficiency can also be maintained relatively constant at distances up to 9 cm. Numerical models were developed and shown to closely match the experimental energy transfer behavior; modeling results indicate that the efficiency can be further doubled by increasing the number of elements. For comparison, an inductive WPT system was also built with the diameters of the transmitting and receiving coils equivalent to the dimensions of the transmitting ultrasonic phased array and receiver transducer, and the acoustic WPT system achieved higher efficiencies than the inductive WPT system when the transmit-to-receive distance is above 5 cm. In addition, beam angle steering was demonstrated by using a simplified seven-element 1-D array, achieving power transfer less dependent on receiver placement.

Smart Piezo-ceramic Coating for Multifunctional Applications

Piezo-ceramic PZT coating was developed with unique combination of the high electro-active properties of ceramics and the mechanical conformability of polymers. The other advantages of the PZT coating is improved electro-mechanical coupling properties, large area coverage, ease of coating on intricate shapes, etc. The developed PZT coating is efficiently used for both sensors and actuators by electrically isolating them from each other or using them in an array for cumulative effects by linking the distributed electrodes. Because of the improved electro-mechanical coupling of insitu PZT layer, the vibration responses of host structures is monitored very effectively by measuring the output voltage from the piezoelectric coating. The developed coating is used for multifunctional applications towards ultrasonic transmitter and receivers for structural health monitoring, strain gauge sensors for natural frequency estimation, actuators for insect scale flapping wing and energy harvesting.

Air-Coupled Ultrasonic Receivers with High Electromechanical Coupling PMN-32%PT Strip-Like Piezoelectric Elements.

For improvement of the efficiency of air-coupled ultrasonic transducers PMN-32%PT piezoelectric crystals which possess very high piezoelectric properties may be used. The electromechanical coupling factor of such crystals for all main vibration modes such as the thickness extension and transverse extension modes is more than 0.9. Operation of ultrasonic transducers with such piezoelectric elements in transmitting and receiving modes is rather different. Therefore, for transmission and reception of ultrasonic signals, separate piezoelectric elements with different dimensions must be used. The objective of this research was development of novel air-coupled ultrasonic receivers with PMN-32%PT strip-like piezoelectric elements vibrating in a transverse-extension mode with electromechanically controlled operation and suitable for applications in ultrasonic arrays. Performance of piezoelectric receivers made of the PMN-32%PT strip-like elements vibrating in this mode may be efficiently controlled by selecting geometry of the electrodes covering side surfaces of the piezoelectric element. It is equivalent to introduction of electromechanical damping which does not require any additional backing element. For this purpose; we have proposed the continuous electrodes to divide into two pairs of electrodes. The one pair is used to pick up the electric signal; another one is exploited for electromechanical damping. Two types of electrodes may be used—rectangular or non-rectangular—with a gap between them directed at some angle, usually 45°. The frequency bandwidth is wider (up to 9 kHz) in the case of non-rectangular electrodes. The strip-like acoustic matching element bonded to the tip of the PMN-32%PT crystal may significantly enhance the performance of the ultrasonic receiver. It was proposed to use for this purpose AIREX T10.110 rigid polymer foam, the acoustic impedance of which is close to the optimal value necessary for matching with air. It was found that in order to get a wide bandwidth the length of the matching strip should be selected not a quarter wavelength λ/4 at the antiresonance frequency but at lower frequency. It allowed achieving the frequency bandwidth (14–18)% with respect to the central frequency at −3 dB level.