This paper focuses on the exploitation of linear-frequency-modulated continuous-wave (LFMCW) radars for noncontact range tracking vital signs, e.g., respiration. Such short-range system combines hardware simplicity and precision, thus outperforming other remote-sensing approaches in addressed biomedical scenario. A rigorous mathematical analysis operating principle LFMCW radar context vital-sign monitoring, which includes explanation key aspects maintenance coherence, is detailed. precise...

This paper presents a hybrid radar system that incorporates linear frequency-modulated continuous-wave (FMCW) mode and an interferometry for indoor human localization life activity monitoring applications. The unique operating principle signal processing method allow the to work at two different modes purposes. FMCW is responsible range detection while activities (respiration, heart beat, body motion, gesture) monitoring. Such cooperation built on each mode's own strength. Beam scanning...

This paper presents a Doppler radar vital sign detection system with random body movement cancellation (RBMC) technique based on adaptive phase compensation. An ordinary camera was integrated the to measure subject's (RBM) that is fed back as information for RBMC. The linearity of system, which strictly related circuit saturation problem in noncontact detection, has been thoroughly analyzed and discussed. It shows larger does not necessarily mean baseband output. High gain configuration at...

This paper presents a Doppler radar sensor system with camera-aided random body movement cancellation (RBMC) techniques for noncontact vital sign detection. The camera measures the subject's motion that is provided to perform RBMC and extract uniform signals of respiration heartbeat. Three strategies are proposed: 1) phase compensation at RF front-end, 2) baseband complex signals, 3) demodulated signals. Both theoretical analysis simulation have been carried out validate proposed techniques....

A hybrid FMCW-interferometry radar sensor is presented. The proposed measurement system incorporates the linear frequency-modulated continuous-wave (FMCW) mode and continuous wave (CW) interferometry mode. works in 5.8 GHz ISM band with a bandwidth of 160 MHz. Equipped special signal processing method, capable detecting absolute distance as well slow motion. Experiments show that position detection has an average accuracy 1.65 cm, relative motion tracking better than 2 mm.

Continuous wave (CW) radar sensors are a promising technology for structural displacement measurement. However, the commonly employed passive backscattering measurement configuration has some limitations low-power applications of CW radar. To improve performance using radar, an active transponder is introduced. Compared with backscattering, capable increasing radar's signal power, thereby to noise ratio more accurate A series laboratory experiments demonstrate was conducted, and experimental...

This paper introduces a homogenisation technique for dry-stacking interlocking masonry structures to improve the modelling and computational efficiency when such brick walls are subjected blast loading. Based on periodic construction pattern, representative volume element (RVE) is derived, whose equivalent material properties determined through numerical under different stress states. Nonlinear strain rate effects both considered in simulations of RVE. The hardening softening behaviour RVE...

Radars are among the best exponents of radio-frequency (RF)/microwave devices for remote sensing [1], [2]. Long-range radars have demonstrated outstanding potential not only defense/security environments, such as detection, location, and tracking targets, but also on a plurality civilian scenarios, meteorological/weather measurement tasks, imaging Earth's surface through synthetic aperture radar (SAR) techniques, monitoring animal migrations, many others [3]-[7].

Doppler radar has been used for small-scale displacement detection, e.g. respiration and heartbeat. The motion amplitude is less than half a carrier wavelength. In this letter, novel technique presented accurate tracking of large-scale several wavelengths, e.g., the water level variation. DC-coupled architecture to ensure precise measurement slow motions even with stationary moment. A signal processing approach proposed increase demodulation linearity deal inconstant amplitude, dynamic dc...

The application of radar sensors to monitor vital signs is currently receiving much attention. Several architectures have been proposed in the technical literature for this task, although with some limitations. Here, a linear-frequency-modulated continuous-wave (LFMCW) approach analyzed. By extracting phase particular range bins, precise tracking (e.g., breathing) could be accomplished, outperforming other approaches. A prototype has built and experimental data coming from...

Abstract In this study, the substitution behavior of Ag atoms in Ti 2 AlC ceramic was investigated using high‐angle annular dark field scanning transmission electron microscopy (HAADF‐STEM). The TEM sample Ag/Ti interaction area prepared following wetting experiment, which carried out at 1030°C for 5 minute sessile drop method. “single atoms” or “nanoclusters” were found crystal lattice substrate. characterizations along two typical crystallographic orientations suggest that both and Al...

Stationary clutter can seriously degrade the performance of radar sensors. In specific context vital‐sign monitoring, this deterioration lead to impossibility tracking desired motions. Pure linear‐frequency‐modulated continuous‐wave (LFMCW) radars have arisen as an interesting solution monitor vital signs, featuring both increased phase‐based range precision and advantageous range‐isolation capability. study, impact on healthcare LFMCW is mathematically analysed a Doppler high‐pass filtering...

A novel water level monitoring technique using continuous-wave (CW) Doppler radar is presented. The CW works with a DC-coupled baseband that allows accurate of the slow-varying level. Ray tracing model has been used to simulate and validate feasibility in presence ripple. proposed robust against clutter interference fluctuation ripples by properly choosing carrier frequency. Experiment was carried out monitor rain barrel when draining out. Both simulation experiment shows can accurately high...

Vibration-based monitoring is one approach used to perform structural condition assessment. By measuring response, such as displacement, dynamic characteristics of a structure may be estimated. Often, the primary responses in civil structures are below 5 Hz, making accurate low frequency measurement critical for successful characterization. In addition, static deflection measurements useful capacity and load rating assessments. This paper presents DC coupled continuous wave radar accurately...

Ocean economy plays a crucial role in the strengthening maritime safety industry and welfare of human beings. Electric Submersible Pumps (ESP) have been widely used floating platforms on sea to provide oil for machines. However, ESP fault may lead ocean environment pollution, other hand, timely diagnosis can improve economy. In order meet strict regulations environmental protection, system has become more popular many countries. The vibration mechanical models typical faults able...

A continuous wave (CW) radar sensor system with active transponders is designed for Structural Health Monitoring (SHM) to accurately measure the structures' vibration while rejecting clutters reflected from surrounding environment. The sensor, a coherent heterodyne architecture, transmits single-tone 2.4 GHz signal and receives returning at 3.3 GHz, thus backscattered GHz. transponder was convert received up 900 MHz reference synchronize sensor. proposed tested in lab environment...

Frequency modulated continuous wave (FMCW) radar is moving from long range detection to indoor short distance target monitoring and has already demonstrated its unique advantages over other approaches. The state-of-the-art coherent FMCW radar, especially, can provide very accurate result in small motion signal detection. However, the performance sensitive clutters that surround target. In this paper, a clutter reduction technique developed further enhance robustness of for physiological Both...

The ability to accurately measure bridge deflections is an important aspect of monitoring and maintenance, both in the US internationally. Static deck are used provide load ratings while dynamic deflection measurements may be track changes behavior due environmental, loading, condition changes. Directly measuring has proven challenging, requiring either a fixed reference point or use non-contact laser sensors. This presentation introduces wireless, continuous wave radar sensors developed for...

Doppler radar has the capability to remotely monitor human respiration. However, in real applications random body movements during measurement will cause drift of "DC" level experiment results. Also, dc shift slowly with temperature change circuit. Those DC drifts inaccurate To solve issue experiments, an automatic DC-correction algorithm is developed. Experiment results show that this eliminates undesirable and offset while recovering useful information original respiration signal. It able...

A novel imaging method based on temporal-spatial stochastic radiation field is a super-resolution technique without the limitation of relative motion between target and radar. For microwave staring coincidence moving target, in addition to distribution scattering coefficient, we also need estimate velocity. When movement information ignored or failing estimate, result will appear serious defocusing affect resolution performance. Inspired by dictionary learning, use sparse...

Abstract Modal property is the crucial factor that can influence vibration characteristics of planetary gear system. Previous studies used time invariant mesh stiffness (TIMS) to study natural characteristics. However, with rotation gear, meshing will change periodically which lead changes modal properties. Based on these properties are ignored in previous studies, a translational-torsional free model base time-varying (TVMS) rather than established this paper system, effects TVMS...

In this paper, the Doppler radar non-contact sensing technology is extended from measurement of one dimensional movement to a practical application in measuring rotational movement. Both simulation and experiment show that can detect speed angular such as electric fans or motor rotation. It has been shown based measurement, baseband output will have dominant fundamental frequency multiple rotation depends on structure reflectors target.

Polarization gradient cooling (PGC) plays an important role in many cold atom applications including the formation of Bose-Einstein condensates (BECs) and single atom. Traditional parameter optimization PGC usually relies on subjective expertise, faces challenges fine manipulation, exhibits low efficiency. Here, we propose a segmented control method that differs from traditional process by expanding experiment parameters 3 to 30. Subsequently, conventional timing problem is reformulated as...

Polarization gradient cooling (PGC) plays an important role in many cold atom applications including the formation of Bose-Einstein condensates (BECs) and single atom. Traditional parameter optimization PGC usually relies on subjective expertise, faces challenges fine manipulation, exhibits low efficiency. Here, we propose a segmented control method that differs from traditional process by expanding experiment parameters 3 to 30. Subsequently, conventional timing problem is reformulated as...