Ultrasonic Radar Research Articles

Highly Linear Phase-Canceling Self-Injection-Locked Ultrasonic Radar for Non-Contact Monitoring of Respiration and Heartbeat.

A novel phase-canceling demodulation scheme to improve the linearity of a self-injection-locked (SIL) ultrasonic radar is proposed with the goal of solving the null detection problem and accurately sensing large displacements of a moving target. A proportional-integral (PI) controller regulates the phase of the injection signal and cancels the Doppler phase shift by tuning a delay in the received echo signal, and this tunable delay serves as the radar output, which is linearly proportional to the displacement of the target. Without assuming weak injection, the frequency and phase equations for an SIL oscillator are derived, supporting the construction of a plant model and the design of a PI controller. Also, a new ultrasonic radar equation is presented for estimating the radar detection range. The SIL radar with phase regulation is operated in its anti-phase injection mode for better performance. The proposed design is implemented on an FPGA to make a 40kHz continuous-wave ultrasonic radar. The maximum detectable peak-to-peak motion is up to 120 mm (approximately 14 wavelengths of displacement), with a total harmonic distortion as low as 2.3% for the detection of 1Hz harmonic motion. The radar is used to detect the human chest movement for non-contact monitoring of the respiratory rate and heart rate. Due to the high linearity and sensitivity, the radar is capable of faithfully detecting the relatively large involuntary body movements and lung movements while still preserving the weak heartbeat rhythm buried in them, with the average error of measured heart rates less than 1 BPM.

A System for Monitoring Breathing Activity Using an Ultrasonic Radar Detection with Low Power Consumption

Continuous monitoring of breathing activity plays a major role in detecting and classifying a breathing abnormality. This work aims to facilitate detection of abnormal breathing syndromes, including tachypnea, bradypnea, central apnea, and irregular breathing by tracking of thorax movement resulting from respiratory rhythms based on ultrasonic radar detection. This paper proposes a non-contact, non-invasive, low cost, low power consumption, portable, and precise system for simultaneous monitoring of normal and abnormal breathing activity in real-time using an ultrasonic PING sensor and microcontroller PIC18F452. Moreover, the obtained abnormal breathing syndrome is reported to the concerned physician’s mobile telephone through a global system for mobile communication (GSM) modem to handle the case depending on the patient’s emergency condition. In addition, the power consumption of the proposed monitoring system is reduced via a duty cycle using an energy-efficient sleep/wake scheme. Experiments were conducted on 12 participants without any physical contact at different distances of 0.5, 1, 2, and 3 m and the breathing rates measured with the proposed system were then compared with those measured by a piezo respiratory belt transducer. The experimental results illustrate the feasibility of the proposed system to extract breathing rate and detect the related abnormal breathing syndromes with a high degree of agreement, strong correlation coefficient, and low error ratio. The results also showed that the total current consumption of the proposed monitoring system based on the sleep/wake scheme was 6.936 mA compared to 321.75 mA when the traditional operation was used instead. Consequently, this led to a 97.8% of power savings and extended the battery life time from 8 h to approximately 370 h. The proposed monitoring system could be used in both clinical and home settings.

Safe sailing: GSM and GPS controlled autonomous boat with overweight detection and obstacle avoidance

<span>This paper aims to save thousands of lives by proposing a novel technique of ensuring the complete safety of medium-sized aquatic vehicles using innovative ideas as well as augmented adaptations of myriad existing technologies. The proposed system incorporates a warning and danger level detection circuit using transistors for switching purposes when the vehicles are overloaded, and a Global System for Mobile (GSM) based module so that the control room can receive alerts and control the engines of such vehicles centrally. A system for detecting and avoiding obstacles is made using ultrasonic radar with ultrasonic transducer JSN SR04t mounted on top of SG90 servo arm which rotates to detect any obstacles. When an obstacle is detected, two other ultrasonic sensors SR-04 gets activated which are placed on two sides of the aquatic vehicle and the ultrasonic transducer becomes fixed on the exact centre. All the three sensors work together to find a free path for the boat to travel. If there is no free path, the boat will stop and wait for the paths to get cleared. The location of the vehicle is tracked by the Global Positioning System (GPS) and a Proportional-Integral-Derivative (PID) controller has been included along with a system which uses values from the GPS module to come back to its original path if it deviates from the original path when avoiding obstacles. A barcode system has been added where it keeps a count on the passengers. The tickets for the vehicle will have barcodes on them which will let the passengers in only if the barcode matches. This is used mainly to keep track of how many people are boarding the vehicle and to prevent those without tickets from boarding.</span>

Application of linear frequency modulated laser ultrasonic radar in reflective thickness and defect non-destructive testing

Radar technology plays an important role in modern aviation and navigation. Radar systems use pulse-compression and match-filtering to detect large moving objects in the sky or in water, or small defects hidden inside industrial components, the object of this paper. We introduce a nondestructive testing (NDT) modality based on frequency-domain laser ultrasound (FDLU) by means of implementing radar principles: Linear-frequency-modulated (LFM chirp) excitation CW laser-beam intensity to perform, ultrasonic signal cross-correlation with the reference signal using pulse-compression and match-filtering, leading to reconstruction of time-domain sequences through inverse Fourier transformation at acceptable signal-to-noise ratios. Theoretically, the laser ultrasound radar (LUR) signal was modelled with both one- and three-dimensional thermoelastic equations, a combination of which was used to simultaneously predict the correct location and relative amplitude of experimental targets with relatively simple mathematical expressions that could not be used either in the 1-D (too simplistic) or in the 3-D (too complicated) approach alone. This methodology was further used to detect buried defects inside a metal alloy. The results demonstrated that the LUR system is capable of determining the thickness of the alloy material and quantitatively estimate the subsurface depth of defects in a signal generation process akin to echolocation.

Transmission Line Unmanned Aerial Vehicle Obstacle Avoidance System Incorporating Multiple Sensing Technologies

UAVs have been used in a large number of applications in transmission line inspections and job monitoring. Infrared detection perception, ultrasonic radar, visual recognition and other perception technologies are integrated into the obstacle perception of UAVs, adding a variety of obstacle detection methods to the UAV, enabling inductive transmission line equipment without dead angles to be detected early. Line equipment and devices in front of man-machine, and can reasonably perform obstacle avoidance operations, effectively reduce the collision accident between UAVs and lines, and improve the safety and reliability of unmanned aerial vehicles on transmission line inspection work, and ensure transmission lines operational safety has a very important role.

Ultrasonic RAdar System (URAS): Arduino and Virtual Reality for a Light-Free Mapping of Indoor Environments

Recently, academia and industry have focused on the creation of new systems for mapping and exploration of unknown spaces in order to create advanced guide systems for robots and people affected by disabilities. In particular, the most common applications are related to the exploration of unknown and/or dangerous spaces that are not accessible to people by exploiting the advantages offered by ultrasonic technology. This work aims at designing a new low-cost system, namely, ultrasonic radar system, to blindly map environments by using ultrasonic sensors, then displaying the acquired information through an Android-based device.

Sistem Penentuan Lokasi dan Penyimpanan Barang Menggunakan LabVIEW dan Sensor Ultrasonik

One of the important aspects in industrial field is a good material handling in logistics. Automated Guided Vehicle (AGV) can be an alternative to making an optimal logistics system. A widely used type of AGV based on its navigation system is line follower robot. This paper explains about applying the line follower robot integrated with LabVIEW to implement ultrasonic sensor as a radar to determine an empty space in logistic storage. The utilization of ultrasonic radar makes the searching process of empty space in the storage faster. Meanwhile, LabVIEW interface is used to help the operator to monitor material handling process. The result of the testing showed that ultrasonic sensor reading in Virtual Instrument LabVIEW has a good precision level when the line follower robot moves in a straight path. The error rate was 6,19% compared to the real situation.Salah satu aspek penting dalam dunia industri adalah penanganan material yang baik pada bagian logistik. Automated Guided Vehicle (AGV) dapat menjadi alternatif untuk mengoptimalkan sistem logistik tersebut. Jenis AGV yang banyak digunakan berdasarkan jenis navigasinya adalah robot pengikut garis. Pada artikel ini, dipaparkan penggunaan robot pengikut garis yang diintegrasikan dengan LabVIEW untuk mengimplementasikan sensor ultrasonik sebagai radar yang berfungsi menentukan lokasi kosong pada tempat penyimpanan barang. Penggunaan radar ultrasonik membuat pencarian ruang kosong pada tempat penyimpanan menjadi lebih cepat, sedangkan untuk membantu operator dalam memonitor proses penanganan material digunakan antarmuka LabVIEW. Berdasarkan hasil beberapa kali pengujian, pembacaan sensor ultrasonik pada Virtual Instrument LabVIEW memiliki tingkat presisi pembacaan cukup baik pada saat pengikut garis bergerak di lintasan lurus. Adapun kesalahan dalam pembacaan sebesar 6,19% dibandingkan dengan kondisi sebenarnya.

Development of control system of robotic platform with ultrasonic radar HC-SR04

Analytical review of known methods of using the ultrasonic radars to detect and round the obstacles is proposed. There are researches of precision distance measurement to the object. It is shown that for distances uncertainty 4-150 cm the distance value is less than 2%. The method of authentication such obstacles, which compares the calculated value and the value is obtained experimentally by using radar. It uses the distance measurement to the object for 3 angles of ultrasonic module rotation. The specified maximum angle of ultrasonic radar platform rotation with fixed signal is reflected from the obstacle. The level of the reflected signal depends on the angle of reflection signal from obstacles, receiver sensitivity, reflectance signal and other parameters. The algorithms based on the data for the platform movement changing and performing round the obstacles are proposed. In the algorithms all possible options for receiving the reflected signal from obstacles are comprised.

<b>Vibration levels on rear and front axles of a tractor in agricultural operations</b> - doi: 10.4025/actascitechnol.v36i1.18170

Excessive vibrations in agricultural tractors can contribute with mechanical failures and subject the operator to discomfort. This work evaluated the vibration levels on rear and front axles of an agricultural tractor working at different forward speeds and wheel drive conditions in plowing and harrowing operations. Field tests were carried out in a completely randomized design in a factorial arrangement 3 x 2 (forward travel speeds x front-wheel-assist enable or disable), with three replications. Tractor vibration was measured using two single axis accelerometers fixed above the rear and front axles. The actual forward speed of the tractor was obtained by means of ultrasonic radar and the angular velocity of the wheels was measured with magnetic transducers. The drawbar force to pull the disc harrow was obtained by a load cell. The results showed that the vibration levels observed for the plowing operation were higher than observed for the harrowing operation. When the front-wheel-assist (FWA) was enabled there was a reduction in vertical vibration levels of the tractor axles. The highest vibration levels were observed in the frequency range of 2 to 4Hz for the both soil tillage operations evaluated

<b>Vibration levels on rear and front axles of a tractor in agricultural operations</b> - doi: 10.4025/actascitechnol.v36i1.18170

Excessive vibrations in agricultural tractors can contribute with mechanical failures and subject the operator to discomfort. This work evaluated the vibration levels on rear and front axles of an agricultural tractor working at different forward speeds and wheel drive conditions in plowing and harrowing operations. Field tests were carried out in a completely randomized design in a factorial arrangement 3 x 2 (forward travel speeds x front-wheel-assist enable or disable), with three replications. Tractor vibration was measured using two single axis accelerometers fixed above the rear and front axles. The actual forward speed of the tractor was obtained by means of ultrasonic radar and the angular velocity of the wheels was measured with magnetic transducers. The drawbar force to pull the disc harrow was obtained by a load cell. The results showed that the vibration levels observed for the plowing operation were higher than observed for the harrowing operation. When the front-wheel-assist (FWA) was enabled there was a reduction in vertical vibration levels of the tractor axles. The highest vibration levels were observed in the frequency range of 2 to 4Hz for the both soil tillage operations evaluated

Joint evaluation of fracture azimuth by electromagnetic wave and elastic wave

Abstract With the multi-wave, multi-component seismic wave exploration, one can apply the anisotropy of fracture media to analyze the attributes of the fracture media, including the fracture azimuth. In the meantime, the techniques of full-polarimetric electromagnetic wave, including full-polarimetric borehole radar, can also be used to analyze the attributes of the fracture. However, the analysis precision of both the multi-component elastic wave exploration and full-polarimetric electromagnetic wave exploration is prone to the influence of noise and other factors. So far, some researchers have conducted studies on the joint inversion of electromagnetic waves and seismic waves. This paper develops evaluation techniques of fracture azimuth by electromagnetic wave, elastic wave, and joint analysis of coincident elastic reflection and electromagnetic data. Firstly, based on the shear wave splitting of elastic waves, this paper develops a statistical analysis technique which applies Pearson correlation coefficient to count and analyze the azimuth angle of fracture. Secondly, based on the information of electromagnetic polarization rotated by fracture, this paper develops a statistical analysis method of full-polarimetric electromagnetic waves which applies the maximum amplitude ratio between the co-polarization and cross-polarization to analyze the azimuth angle of fracture. Furthermore, based on the analysis result of the elastic wave and full-polarimetric electromagnetic wave, this paper develops a joint analysis technique which adopts the standard deviation. At last, authors in this study conduct joint detection experiments on the coincident fracture medium by using the ultrasonic and full-polarimetric ground penetrating radar. The experimental result indicates that both single geophysical methods are capable of analyzing the fracture azimuth angle, but the joint analysis is more accurate.

UIR-Scanner Potential to Defect Detection in Concrete

In the research three NDT methods: indirect Ultrasonic Pulse Velocity, Impact-Echo (IE) and Ground Penetrating Radar (GPR) were used for investigation of concrete slabs with well-defined reinforcement and artificial defects. The obtained results shows the big potential of combination of UPE, IE and GPR methods for detection of wide range of defects in concrete structures. These methods were implemented for UIR scanner development – NDT system which accelerate assessment of concrete structure. Moreover, when the result of one method is not clear and individually the method seems to be not effective, the data from the other one allows for proper interpretation of concrete integrity.

Study on Grouting Effect Evaluation of F4 Weathered Slot in Xiamen Xiang’an Submarine Tunnel

Measurement of water inflow from borehole, drilling and coring, ultrasonic inspection, ground-penetrating radar and field excavation are all used to test effect of grouting water shutoff and reinforcement in F4 weathered slot of Xiamen Xiang’an submarine tunnel. The five test ways are inter-validated to determine the grouting effect accurately and reasonably. It can provide a reliable basis for grouting design, construction and grouting effect test in similar strata. The application and development of grouting in submarine tunnel can be promoted.

Elderly People Behavior Detection System Using Several Ultrasonic Radars

Elderly People Behavior Detection System Using Several Ultrasonic Radars

Safety Confirmation System Using Ultrasonic Radar for Elderly People Living Alone

In Japan, the number of elderly people living alone has increased in recent years. Therefore, we propose a safety confirmation system that includes an ultrasonic radar for confirming the safety of elderly people living alone. This system consists of an ultrasonic radar, a power line communication unit, and an information processing communication unit. The safety confirmation method performs the human body detection in the restroom using ultrasonic radar. In addition, the proposed system contains a self-checking function. The effectiveness of the proposed system has been confirmed by the results of a field experiment.

送信信号デューティ比変更法による超音波レーダ型離床検知装置の非干渉化

The decline in the quality of patient's safety control is a problem, because the number of caretakers is reduced by the acceleration of demographic aging in an elder care facility. Especially, the detection of getting up from the bed is very important for preventing patients from falling and wandering unbreakable. In our previous study, we have developed the getting up detection device with an ultrasonic radar, which is safe, cheap, and break-proof. However, if there are many patients in a ward, it is difficult to use some ultrasonic radars. The reason is that if some ultrasonic radars, which have the same frequency, are used in same ward, the ultrasonic signals are coherent with each other. To solve this problem, we propose a novel incoherent method. This method is achieved by improving the software in the device at a low cost.

A Novel Method of Distance Measurement Based on Pulse Position Modulation and Synchronization of Chaotic Signals Using Ultrasonic Radar Systems

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 according to the PPM method and transmitted by the sensor. The received signal is demodulated, and the demodulated signal forces a slave chaotic system to generate the chaotic signal embedded in it, which allows recovery of the sinusoidal signal by subtracting this chaotic signal from the demodulated echo. The difference of the phases of the reference sinusoidal signal and the recovered sinusoidal signal allows computation of the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">time</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">of</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">flight</i> of the signal and, consequently, the distance of the radar system from the obstacle. The novel method is illustrated and tested by both simulation and experiments. The interference problem between the considered radar system and other radar systems ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">crosstalk</i> ) is also addressed, and a solution is proposed to avoid it.

Sophisticated Ultrasonic Radar System Adopted by Flying Bats

Small bats (microchiroptera) get various types of information about their targeted objects by comparing returning echoes to emitted ultrasonic pulses, which is called “Biosonar”. This paper introduces the outline of biosonar, and then explains consistency and plasticity of vocalization, changes in vocalization due to relationships between targets and the bat. This paper also describes how they vocalize for the real-time time-sharing signal processing based upon data obtained with an onboard telemetry microphone system and data recorded with reversible focal inactivation of neural activities. Amazing real-time time-sharing signal processing performed by a brain as small as the tip of our little finger will be explained.

Movement Confirmation System using Ultrasonic Radar and Power Line Communications for senior citizens

Movement Confirmation System using Ultrasonic Radar and Power Line Communications for senior citizens

1A1-N-095 低プライバシ侵害性の行動観察システム : 超音波タグ・レーダ統合システムによる人とモノの位置計測(デジタルヒューマン1,生活を支援するロボメカ技術のメガインテグレーション)

1A1-N-095 低プライバシ侵害性の行動観察システム : 超音波タグ・レーダ統合システムによる人とモノの位置計測(デジタルヒューマン1,生活を支援するロボメカ技術のメガインテグレーション)