Ultrasonic Transmitters Research Articles

Design of transmitting and receiving circuit of ultrasonic transducer based on STM32

In order to meet the needs of ultrasonic in industrial detection, an ultrasonic transmitter and receiver circuit based on STM32 is designed. The transmitting circuit is controlled by the optocoupler control isolation circuit and the MOSFET drive circuit to generate high-voltage excitation pulses to drive the ultrasonic transducer; the receiving circuit which achieves Processing of ultrasonic echo signals includes a limiter circuit, a preamplifier circuit, a Butterworth band-pass filter circuit and an automatic gain circuit, etc The actual test shows that the ultrasonic excitation signal generated by the system has the characteristics of low noise and steep waveform. The processed echo signal is clear, the system performance is good and the structure is simple, stable and reliable.

Leakage estimation in water networks based on the BABE and MNF analyses: a case study in Gavankola village, Iran

Abstract Calculating the water loss and leakage in the water distribution networks (WDNs) is performed for various reasons such as monitoring and optimizing, active control, estimating economical damage, and predicting the demand in the network development plans. In this research, two leakage calculation methods including Background and Bursts Estimates (BABE) and minimum night flow (MNF) have been evaluated for a rural network in the north of Iran with a high non-revenue water (NRW) percentage of 47%. Initially, the data related to the inlet flow rate of the network and the average pressure at zone was measured using ultrasonic flow meters and pressure transmitter, respectively. Then, remote data loggers collected these data. With the water loss analyses based on the BABE method (annually) and based on the MNF technique (every 10 minutes), the average leak was found to be 1.45 and 1.105 Lit/s, respectively. Also, according to hydraulic and consumption conditions, the highest frequency of MNF occurrence was observed at 00:00 and 05:00. Moreover, the effects of legitimate night-time consumption (LNC) and leakage exponent (N) were evaluated. The results indicate that determining the LNC, especially in the networks in which the domestic customers use private tanks, is significantly important.

Characterization of an Ultrasonic Local Positioning System for 3D Measurements.

Indoor location and positioning systems (ILPS) are used to locate and track people, as well as mobile and/or connected targets, such as robots or smartphones, not only inside buildings with a lack of global navigation satellite systems (GNSS) signals but also in constrained outdoor situations with reduced coverage. Indoor positioning applications and their interest are growing in certain environments, such as commercial centers, airports, hospitals or factories. Several sensory technologies have already been applied to indoor positioning systems, where ultrasounds are a common solution due to its low cost and simplicity. This work proposes a 3D ultrasonic local positioning system (ULPS), based on a set of three asynchronous ultrasonic beacon units, capable of transmitting coded signals independently, and on a 3D mobile receiver prototype. The proposal is based on the aforementioned beacon unit, which consists of five ultrasonic transmitters oriented towards the same coverage area and has already been proven in 2D positioning by applying hyperbolic trilateration. Since there are three beacon units available, the final position is obtained by merging the partial results from each unit, implementing a minimum likelihood estimation (MLE) fusion algorithm. The approach has been characterized, and experimentally verified, trying to maximize the coverage zone, at least for typical sizes in most common public rooms and halls. The proposal has achieved a positioning accuracy below decimeters for 90% of the cases in the zone where the three ultrasonic beacon units are available, whereas these accuracies can degrade above decimeters according to whether the coverage from one or more beacon units is missing. The experimental workspace covers a large volume, where tests have been carried out at points placed in two different horizontal planes.

Direction and distance sensors and sensing system for elderly people

Elderly people need either a caretaker or a cart to carry their belongings in and around their house or to/from nearby places, like a shopping mall, bus stop etc. This paper reports the development of a direction-cum-distance sensing system (DDSS) using ultrasonic sensors for a cart to assist elderly people. The DDSS can convert an ordinary assistive cart into a person-following assistive robot cart that would follow its user/target. Instead of using infrared or vision-based tracking systems for sensing direction and distance, as reported by other researchers, the DDSS reported here uses ultrasonic beam/pulses. The DDSS integrates the two tasks of finding the direction and measuring the distance in a single unit. For finding the direction of the target (user), an ultrasonic transmitter is placed on the back of the target, whereas two ultrasonic sensors are placed on the front of the cart. The distance of the target from the cart is measured using the classical technique of measuring the time taken by ultrasonic pulses to travel from the cart up to the target and back from the target to the cart after its reflection from the target. Performance of the DDSS in direction mode has been evaluated experimentally, which is very gratifying. Since the DDSS works with ultrasonic beam/pulses, the assistive robot cart can work not only indoor but also outdoor (where infrared emissions from the sun and other sources may cause mal-operation of infrared-based tracking systems) and in low-visibility areas (where camera-based tracking systems may fail to work). The new DDSS has additional advantages of simplicity, ready availability of components and low cost. Some suggestions for further work are included in the last section of the paper.

A Miniature Robotic Turtle With Target Tracking and Wireless Charging Systems Based on IPMCs

State-of-the-art autonomous micro-robotic turtles suffer from various limitations, such as power restrictions that minimize their deployment times. In this paper, an Ionic Polymer Metal Composite (IPMC) actuator-based centimeter-level biomimetic underwater robot was designed and developed as a robotic turtle with self-charging capabilities to overcome such limitations. It could move forward and make turns driven by five IPMCs on the water. The underwater charging station was able to transmit wideband ultrasonic and electromagnetic fields for electromagnetic induction charging. An ultrasonic communication system with one ultrasonic transmitter and two ultrasonic receivers was first fabricated to implement communication between the underwater station and the biomimetic underwater robot for autonomous tracking and rechargeable capabilities. Experiments were carried out to confirm the operation of the biomimetic underwater robot, which verified the centimeter-level rechargeable capabilities and autonomous target tracking features. The micro-robot demonstrated a self-tracking radial displacement error of approximately 6 mm and a charging reliability rate of more than 73%.

Air-writing via Receiver Array Based Ultrasonic Source Localization

Air-writing systems have recently been proposed as tools for human-machine interaction where instructions can be represented using letters or digits written in the air. Different technologies have been used to realize air-writing systems. In this article, we propose an air-writing system using acoustic waves. The proposed system consists of two components: a motion-tracking component and a text recognition component. For motion tracking, we utilize direction-of-arrival (DOA) information. An ultrasonic receiver array tracks the motion of a wearable ultrasonic transmitter by observing the change in the DOA of the signals. We propose a novel 2-D DOA estimation algorithm that can track the change in the direction of the transmitter using measured phase differences between the receiver array elements. The proposed phase-difference projection (PDP) algorithm can provide accurate tracking with a three-sensor receiver array. The motion-tracking information is passed next for text recognition. To this end, and in order to strike the desired balance between flexibility, processing speed, and accuracy, a training-free order-restricted matching (ORM) classifier is designed. The proposed air-writing system, which combines the proposed DOA estimation and text recognition algorithms, achieves a letter classification accuracy of 96.31%. The utility, processing time, and classification accuracy are compared with four training-free classifiers and two machine learning classifiers to demonstrate the efficiency of the proposed system.

A lab-on-chip ultrasonic platform for real-time and nondestructive assessment of extracellular matrix stiffness.

Extracellular matrix (ECM) mechanical stiffness and its dynamic change is one of the main cues that directly affects the differentiation and proliferation of normal cells as well as the progression of disease processes such as fibrosis and cancer. Recent advancements in biomaterials have enabled a wide range of polymer matrices that could mimic the ECM of different tissues for a wide range of in vitro basic research and drug discovery. However, most of the technologies utilized to quantify the stiffness of such ECM are either destructive or expensive, and therefore are unsuitable for the in situ, long-term monitoring of variations in ECM stiffness for on-chip cell culture applications. This work demonstrates a novel noninvasive on-chip platform for characterization of ECM stiffness in vitro, by monitoring ultrasonic wave attenuation through the targeted material. The device is composed of a pair of millimeter scale ultrasonic transmitter and receiver transducers with the test medium placed in between them. The transmitter generates an ultrasonic wave that propagates through the material, triggers the piezoelectric receiver and generates a corresponding electrical signal. The characterization reveals a linear (r2 = 0.86) decrease in the output voltage of the piezoelectric receiver with an average sensitivity of -15.86 μV kPa-1 by increasing the stiffnesses of hydrogels (from 4.3 kPa to 308 kPa made with various dry-weight concentrations of agarose and gelatin). The ultrasonic stiffness sensing is also demonstrated to successfully monitor dynamic changes in a simulated in vitro tissue by gradually changing the polymerization density of an agarose gel, as a proof-of-concept towards future use for 3D cell culture and drug screening. In situ long-term ultrasonic signal stability and thermal assessment of the device demonstrates its high robust performance even after two days of continuous operation, with negligible (<0.5 °C) heating of the hydrogel in contact with the piezoelectric transducers. In vitro biocompatibility assessment of the device with mammary fibroblasts further assures that the materials used in the platform did not produce a toxic response and cells remained viable under the applied ultrasound signals in the device.

Automation using Plc and IIOT Monitoring in Jaggery Preparation

Jaggery is a natural sugar which a sweetening agent and is also called as gur or panela. It is first made into a semisolid paste by evaporating the sugarcane juice. The aim of this paper is to develop an automated process for Jaggery preparation using PLC and monitored by IIOT (Industrial Internet Of Things). The process consists of pushbuttons, Temperature sensor (LM35), Level sensor (Ultrasonic level transmitter), IR sensor as input devices which are interfaced with the Siemens PLC(CPU314-2C). The PLC controls the following output devices such as crusher motor, conveyor motor, scum motor and valves (pneumatic actuator control valve).The process parameters are uploaded into the cloud for monitoring using IIOT. The trend graphs are generated using MindSphere software (MindConnect Nano). The system also provides fault detection through alert messages and e-mails. The protocol used for IIOT is Transmission Control Protocol (TCP). All the five stages such as crushing, filtering, heating, cooling and molding of the Jaggery preparation process are automated. Thus, a hygienic and fully automatic PLC based Jaggery production system with fault detection capability is developed through this project

Klasifikasi Tingkat Kemurnian Bahan Bakar Minyak Berdasarkan Cepat Rambat Gelombang Menggunakan Algoritma K-Nearest Neighbor

The need for fuel oil has increased along with the increase of population, the number of vehicles and industries. An increase in demand for fuel oil is used by some people to make a profit by selling mixed fuel oil at the same price as the price set by the government. The purpose of this study is to create a prototype device that can characterize the type of fuel oil and create a classification system to determine the level of fuel purity with 40 kHz ultrasonic waves based on the parameters of wave velocity using the K-Nearest Neighbor (KNN) algorithm.This device works by using a 40 kHz ultrasonic wave that is connected to an ultrasonic transmitter. The propagated wave will be received by the ultrasonic receiver. The wave received by the receiver will be amplified and connected to the comparator circuit so that it can be processed by a microcontroller. Data obtained using this tool are wave travel time, wave velocity, density, and attenuation. The data used for classification systems using the KNN algorithm is wave velocity.Classification using the KNN algorithm can identify the level of fuel purity based on the parameters of the wave velocity obtained from ultrasonic wave gauges with an accuracy of 72.50%. Wave velocity which is measured using ultrasonic waves is directly proportional to the actual speed with the largest percentage of deviations that is 0.34%.

Truncated Conical PVDF Film Transducer for Air Ultrasound

In this paper, a truncated conical polyvinylidene fluoride (PVDF) film transducer for air ultrasound is investigated. The transducer was designed and fabricated using two identical pieces of fan-shaped PVDF film that makes the curve direction as consistent as possible with the molecular orientation direction of the film. The transducer has a truncated conical geometry, which provides a wide bandwidth with wide vertical beam angle. Measurements of the frequency response of transmitter output, angular performance, and pulse response are presented. The results show that the radiation directivity pattern of the transducer is in the axial direction of the conical film and the beam width is 140° at −6dB level, which is more than that of the commercial 40-kHz ceramic transducers and cylindrical PVDF transducers. Therefore, this ultrasonic transducer is well-suited for three-dimensional (3D) ultrasonic positioning systems, and in particular for mounting at the conical head of electronic pens as an ultrasonic position transmitter.

A simple levitated-drop tensiometer.

A reliable, simple, and affordable liquid tensiometer is presented in this paper. The instrument consists of 72 ultrasonic transmitters in a tractor beam configuration that levitates small liquid samples (droplets) in air. Under operation, the instrument imparts a pressure instability that causes the droplet to vibrate while still levitating. Droplet oscillations are then detected by a photodiode, and the signal is recorded by an oscilloscope. The frequency of these oscillations is obtained and then used to obtain the effective surface tension of the sample. The instrument operates at the millisecond scale time (t < 12.5 ms), with very small liquid volumes (∼0.5 μl), and the sample is recoverable after testing. The instrument has been experimentally validated with acetone, ethanol, Fluorinert FC-40, water, and whole milk.

Ultrasound Sensor-Based Wireless Power Transfer for Low-Power Medical Devices

Ultrasonic power transfer (UPT) is a promising method for wireless power transfer technology for low-power medical applications. Most portable or wearable medical devices are battery-powered. Batteries cannot be used for a long time and require periodic charging or replacement. UPT is a candidate technology for solving this problem. In this work, a 40-KHz ultrasound transducer was used to design a new prototype for supplying power to a wearable heart rate sensor for medical application. The implemented system consists of a power unit and heart rate measurement unit. The power unit includes an ultrasonic transmitter and receiver, rectifier, boost converter and super-capacitors. The heart rate measurement unit comprises measurement and monitoring circuits. UPT-based transfer power and efficiency were achieved using 1-, 4- and 8-Farad (F) super-capacitors. At 4 F, the system achieved 69.4% transfer efficiency and 0.318 mW power at 4 cm. In addition, 97% heart rate measurement accuracy was achieved relative to the benchmark device. The heart rate measurements were validated with statistical analysis. Our results show that this work outperforms previous works in terms of transfer power and efficiency with a 4-cm gap between the ultrasound transmitter and receiver.

Multi-Ring Ultrasonic Transducer on a Single Piezoelectric Disk For Powering Biomedical Implants.

This paper presents a novel ultrasonic transmitter with the ability of focusing ultrasonic waves for maximum power transmission at different depths for brain neurostimula-tor implants. The most important advantages of the proposed multi-ring ultrasonic transducer (MRUT) is its simplicity and no requirement of any lens or air cavity for focusing the ultrasonic waves. Furthermore, adjusting the focal point compared to the conventional transducers is significantly easier, especially as the location of implants may vary due to, for example, head movement or the need of using these implants at different depths. By the use of multiple rings on a single piezoelectric disk in our transducer, not only more focused ultrasound beams can be achieved, but also the side lobes can be diminished by exciting each rings with different electrical signal. The proposed transmitter is envisioned to be used for optogenetic stimulation of neurons in freely-moving animals.

IMPROVEMENT OF OIL EXTRACTION PROCESS USING ULTRASONIC TECHNIQUE AS A SECOND-GENERATION BIOFUEL SOURCE

The aim of this study was to optimize machine efficiency and the energy content of safflower oil by the ultrasonic technique. The developed machine has an improved effective technique using ultrasonic transmitter system that provide different frequency levels with a regulated power supply. Ultrasonic transmitter system can be described starting from a regulated power supply circuit where a transformer is used to step-down the voltage from 230 to 12 VAC while the voltage is rectified using the full wave bridge rectifier where the rectifier converts the sine waves into a series of positive peaks. The rectified AC voltage is then smoothed or filtered by a capacitor C1, C2 and C3. Finally, the voltage is passed through a regulator LM7809 to create a fixed 9VDC output with less ripple in the voltage. Circuit of the ultrasonic transmitter runs by using a 9VDC regulated power supply. Design of the ultrasonic generator is essentially built a SA555 stable oscillator. This oscillator generates a frequency from 10 to 70 kHz which is used by the transmitting transducer to generate the ultrasonic wave. The performance of the developed machine was studied under four levels of ultrasonic frequency (20, 30, 40 and 50 kHz) and four different feed rates (125, 145, 160, and 170 kg.h-1) and estimate of its effect on the oil yield, machine efficiency and the energy content of safflower oil. The extracted oil was subjected to determine properties of them like: the specific gravity, viscosity, heating value, flash point, carbon residue, and sulphur content. The ultrasonic assisted extraction improves the oil yield by 29.33, % and the highest energy content value was achieved 2034 MJ.h-1 measured at frequency level of 40 kHz and feed rate of 160 kg.h-1. This will be useful to the extraction machine to recover higher amount of the oil yield from same amount of the safflower seeds throughout the operational period. Also, the oil extraction machine has been developed with a machine efficiency of 94.60% as well as decreasing energy consumption by 22.94%.

Using Ultrasonic Telemetry to Evaluate Paddlefish Spawning Behavior in Harry S. Truman Reservoir, Missouri

AbstractLarge‐river fishes (e.g., sturgeons [Acipenseridae] and Paddlefish Polyodon spathula) that inhabit reservoir systems are potentially unable to sense environmental cues that elicit typical life history behaviors. These cues can be masked by altered hydrology and temperature regimes. In many reservoirs throughout North America, Paddlefish populations are potentially affected by these unnatural conditions. In an attempt to understand and identify the potential mechanisms that limit Paddlefish reproduction in reservoir systems, we selected Harry S. Truman Reservoir (Truman Lake), Missouri, as our study area of focus. This population is supplemented by stocking, and although anecdotal evidence of potential natural reproduction exists, spawning has never been documented. We implanted ultrasonic transmitters into 113 reproductively mature Paddlefish, and the movements of these fish were tracked over 2 years. Paddlefish migratory behavior was significantly related to water temperature and gauge height, and differences in movement behaviors existed between sexes. Spring aggregations were located in the riverine portion of the Osage River, and embryos and larvae were sampled in 2015 and 2016 near said aggregations. Using acoustic telemetry and egg mats, we acquired evidence suggesting that the Truman Lake Paddlefish are spawning. Our technique can likely be applied to determine spawning locations for Paddlefish inhabiting other large reservoirs.

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.

End-to-End Design of Efficient Ultrasonic Power Links for Scaling Towards Submillimeter Implantable Receivers.

We present an analytical framework for optimizing the efficiency of ultrasonic wireless power links for implantable devices scaled down to sub-mm dimensions. Key design insights and tradeoffs are considered for various parameters including the operating frequency, the transmission depth, the size of the transmitter, the impedance and the aperture efficiency of the miniaturized receiver, and the interface between the receiver and the power recovery chain on the implant. The performance of spherically focused transducers as ultrasonic transmitters is analyzed to study the limits and the tradeoffs. Two optimization methods are presented: "Focal Peak" sets the focus of transducers at target depths, and "Global Maximum" maximizes the efficiency globally with off-focus operation. The results are also compared to phased array implementations. To investigate the efficiency of implants, miniaturized receivers made from single crystalline piezoelectric material, PMN-PT, are used as they have resonances in the derived optimal carrier frequency range (∼1-2 MHz). A methodology to achieve an efficient interface to the power electronics is then provided using an optogenetic stimulator as an example platform. The analytical results are verified through both simulations and measurements. Finally, an example ultrasonic link using a spherical transmitter with a radius of 2cm is demonstrated; link efficiencies of 1.93-0.23% are obtained at 6-10cm depths with sub-mm receivers for the optogenetic application.

Pilot acoustic tracking study on young of the year scalloped hammerhead sharks, Sphyrna lewini, within a coastal nursery area in Jalisco, Mexico.

A preliminary experience to study, on a small scale, the movements of the young of the year (YOY) Sphyrna lewini (Griffith & Smith, 1834), in the Mexican Central Pacific, using acoustic telemetry within a nursery area. From October to December 2014 seven sharks were tagged with ultrasonic transmitters and tracked for 68 days within a 14 km2 area associated to a river mouth. The quick shark handling allowed their release in less than two minutes and excellent health condition. Although recaptured sharks up to 105 days after tagging did not show symptoms of scar infection, a slight abrasion in the shark skin was observed after 51 days. The ultrasonic transmitter retention was 75%, and the site fidelity was complete (F = 1) during the first ninety days. For the 135-day period, fidelity was 0.63 (0.40-0.80), and the estimated attrition rate was 0.73 (0.34-1). Ninety-seven percent of detections occurred on soft bottoms and less than 30 m depth. The YOY S. lewini stayed active 24 h a day and performed estimated movements of 11.96 km during that time. The home range for all tagged sharks was estimated to be 4.82 km 2 using the minimum convex polygon method (MCP) and 4.89 km 2 using the kernel utilization distribution method (95% KUD). The KUD estimation showed two core areas within the study area, is the one located in front of the river mouth the most used.

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.

Association of early juvenile yellowfin tuna &lt;i&gt;Thunnus albacares&lt;/i&gt; with a network of payaos in the Philippines

To understand how early juvenile yellowfin tuna use the habitat and environment provided by fish aggregating devices (FADs), fish (19–31 cm FL) implanted with ultrasonic transmitters into their abdominal cavities were released in a network of payaos in Panay Gulf, the Philippines. Self-recording receivers were attached to the anchor ropes of the payaos to detect the presence of the fish. Some aspects of the behavior of juveniles were similar to those reported in adults. One juvenile showed a diurnal vertical swimming pattern, swam within a limited shallow range during the nighttime, and dived to deeper waters during the daytime. Two juveniles performed deep dives over 100 m during payao-to-payao excursion. Three juveniles showed a diurnal horizontal swimming pattern that was synchronized. In contrast, juveniles stayed <6 days in the network, shorter than adults. No juveniles returned to the same payao after an interruption of over 24 h. It is suggested that juveniles in this area are just starting to migrate and are temporarily staying around a payao for a few days to forage before continuing their migration.