Wireless Communication Unit Research Articles

State Evaluation of Self-Powered Wireless Sensors Based on a Fuzzy Comprehensive Evaluation Model.

The energy harvesters used in self-powered wireless sensing technology, which has the potential to completely solve the power supply problem of the sensing nodes from the source, usually require mechanical movement or operate in harsh environments, resulting in a significant reduction in device lifespan and reliability. Therefore, the influencing factors and failure mechanisms of the operating status of self-powered wireless sensors were analyzed, and an innovative evaluation index system was proposed, which includes 4 primary indexes and 13 secondary indexes, including energy harvesters, energy management circuits, wireless communication units, and sensors. Next, the weights obtained from the subjective analytic hierarchy process (AHP) and objective CRITIC weight method were fused to obtain the weights of each index. A self-powered sensor evaluation scheme (FE-SPS) based on fuzzy comprehensive evaluation was implemented by constructing a fuzzy evaluation model. The advantage of this scheme is that it can determine the current health status of the system based on its output characteristics. Finally, taking vibration energy as an example, the operational status of the self-powered wireless sensors after 200 h of operation was comprehensively evaluated. The experimental results show that the test self-powered wireless sensor had the highest score of "normal", which is 0.4847, so the evaluation result was "normal". In this article, a reliability evaluation strategy for self-powered wireless sensor was constructed to ensure the reliable operation of self-powered wireless sensors.

Sweet-Tooth: Resonators on Sugar

The development of biodegradable electronics enables environmentally friendly devices for environment monitoring and healthcare. An important component of many such systems is a wireless communication unit which needs a resonator. In this work, we investigate the design of LC resonators on isomalt, a form of beet-sugar, used as the base substrate or scaffold. Isomalt is widely used in sugar-art and can be sculpted into mechanically stable various forms. We take advantage of this feature to explore four inductor geometries, namely, planar, sculpted helix, Fe doped core and toroidal. The isomalt substrate is also used to design parallel plate capacitors. Based on these design LC resonators are characterized. Keeping in mind potential applications for edible electronics, the work finally discusses the overall performance of resonators keeping in mind the toxicity limit of the constituents.

Free-Space Optical Communication with an Optimized Lipschitz Exponent for Biosignal Telemetry

Abstract Healthcare monitoring is a rapidly developing network in the field of advanced medical treatment. The network combines the ideology of wireless communication, signal processing, medical information and real-time processing units to support the medical monitoring system. The proposed work focuses on the development of a Free-Space Optical (FSO) system to transmit the biosignals from a remote distance to the physician. Generally, the data transmitted over the FSO system is affected by various atmospheric conditions such as air medium, O2, and H2O molecules. To tackle these problems, the Biosignals Electrocardiogram (ECG) and Electroencephalogram (EEG) are processed in the Optimized Lipschitz Exponent (OLE) function before transmission over the FSO medium. In this novel technique, the OLE function measures the informative data from the biosignals by calculating the local regularities and singularity. This collects the most informative signals and transmits them in the signal over the FSO medium. This particular hybridization helps to transmit the required data without distortion. The Bit Error Rate (BER) of 10−9 is obtained, which satisfies the healthcare monitoring condition. The result section shows that the proposed model has minimum losses compared to the original signal.

Research and Application of Energy-Efficient Management Approach for Wireless Sensor Networks.

Wireless sensor networks (WSNs) are widely used in industrial applications. However, many of them have limited lifetimes, which has been a considerable constraint on their widespread use. As a typical application of WSNs, distributed measurement of the electric field under high-voltage direct-current (HVDC) transmission lines also suffers from this issue. This paper first introduces the composition of the electric-field measurement system (EFMS) and its working principle. Considering the actual power supply of the system, this paper mainly introduces the composition of the wireless sensor node (WSND) and analyzes the power consumption and potential working state transformation of the WSND, together with a comprehensive study on parameters affecting the power consumption of the wireless communication unit. Moreover, an energy-efficient scheduling approach is proposed after specially designing a working sequence and the study on system parameters. The proposed approach is verified by experiments on not only the experimental line of the national HVDC test base, but also a commercial operation HVDC transmission line with the challenge of long endurance, which is considered in this paper with a new strategy. The results show that the proposed method can greatly extend the lifetime of the WSND.

U-WeAr: User Recognition on Wearable Devices through Arm Gesture

The use of wearable devices equipped with inertial sensors has become increasingly pervasive. It has been widely demonstrated in the literature that inertial signals acquired by these sensors can be used by machine learning algorithms to predict actions performed and/or to recognize the identities of the person wearing the sensors. In this article, we present a hardware/software system for arm gesture recognition, identity recognition, and verification of a person based on inertial sensors. The hardware part is a custom wristband that consists of a computing unit, a wireless communication unit, and an inertial sensor. The software part is an algorithm based on recurrent neural networks that is able to process the signals coming from the sensor and to return a prediction. To validate the system, a dataset consisting of 25 symbols drawn with the arm is collected. These symbols are performed by 33 subjects. We conduct two evaluations: 1) performance evaluation for arm gesture recognition, user recognition and verification; and 2) usability assessment of the system. The performance of the three recognition tasks indicate that this system can be reliably applied in real environments with an accuracy above 96% for gesture recognition, an accuracy of about 85% for user identification, and an equal error rate of about 13% for user verification. The outcome of the usability test proves a great satisfaction from the users in terms of high simplicity in the use of the wristband and goodness of the machine learning predictions.

Self-powered pumping switched TENG enabled real-time wireless metal tin height and position recognition and counting for production line management

Harvesting high entropy energy using triboelectric nanogenerator (TENG) has attracted more and more attentions. For normal self-powered wireless sensing applications, a significant portion of harvested energy will be consumed by the subsequent power management and wireless communication units, leading to the incapability of real-time wireless sensing. In this paper, we proposed a pumping switched TENG (PSW-TENG) for real-time wireless sensing. An inductor magnetic sensor coil integrated with the TENG forms a LC resonant circuit, converts the pulsed output of TENG into resonant signal with the encoded sensing information，which is significantly boosted using an integrated microswitch and a charge pump, and then transmitted via a laser diode up to 2 m. The sensor system has been utilized to detect metallic components passing through. The self-powered metal component monitoring system has a height recognition sensitivity of 11.7 kHz/mm and a horizontal position recognition sensitivity of 5.6 kHz/mm with the largest error of 8.5 kHz, showing good sensitivity and stability. Based on the sensing system, the types and passing number of tins on a conveyor can be simultaneously identified and counted. All the results have demonstrated the great potential of the real-time self-powered wireless sensing system for production line management.

Fully integrated flexible long-term electrocardiogram recording patch with gel-less adhesive electrodes for arrhythmia detection

A mechanically flexible and fully integrated electrocardiogram (ECG) recording patch (ERP) that simultaneously monitors the ECG signals and detects the arrhythmia is presented. A simplified two-step process is applied to fabricate the acetylene carbon black (AB)/ polydimethylsiloxane (PDMS) electrodes. The soft and adhesive nature of polymer composite electrodes allows conformal contact to the skin. The ERP integrates ECG front end circuits, microcontroller chip and wireless communication unit on a flexible printed circuit boards (FPCB) with electrodes attached on its back, which bridges the technological gap among the signal acquisition, processing, and wireless transmission in the wearable electronics. The ERP can be deformed easily under stretching and bending actions by a special connection of two squares through serpentine traces. With the concentration of 7 wt% AB, the average signal-to-noise ratio (SNR) of the built electrodes at different postures (sit, stand and walk) during electrocardiography are assessed as 17.4 dB, 16.1 dB and 5.6 dB, respectively. Similarly, the SNR of the ERP with Ag/AgCl electrodes are 22.1 dB, 20.6 dB and 10.3 dB, respectively. The performance of the AB/PDMS electrodes are very close to the standard Ag/AgCl electrodes. In addition, the ERP have the ability of anti-interference from environmental noise and motion artifacts (MA). Benefited from implemented microcontroller unit (MCU) platform, the ERP allows sophisticated signal processing with the introduction of discrete wavelet transform (DWT) and support vector machine (SVM) algorithms, which achieves high classification accuracy of 98.7% for online arrhythmia detection. The designed platform provides a wide range of applications for other personalized physiological monitoring and diagnosis.

Design of Dual Ultra–Wideband Band–Pass Filter Using Stepped Impedance Resonator λg/4 Short Stubs and T–Shaped Band-Stop Filter

Portable wireless communication systems are increasingly in demand in small sizes for human convenience. In wireless communication systems, the performance, size, and unit cost are very important. A band−pass filter is important to sharp cut–off frequency characteristics, size, and frequency selectivity in wireless communication systems. The band−pass filter has three types of techniques in the transmission−zero method, stub−loaded resonator, and stepped impedance resonator for the sharp cut−off frequency characteristic, adjustable bandwidth, and excellent frequency response characteristics. To obtain these characteristics, the impedance ratio and length of a stub are mainly adjusted. It also utilizes a multi–mode technique to increase bandwidth. However, it is analyzed that the problem of reducing the size of the device still remains. To solve these problems, the paper is applied to a stub−loaded resonator and a stepped impedance resonator to control the impedance ratio and the length of the stub to obtain the results of the transmission−zero method, bandwidth control, and size reduction through the folded structure. Dual−band bandwidth was secured by integrating a T−shaped band−stop filter. The designed band–pass filter has center frequencies of 243 GHz and 7.49 GHz, and the insertion loss of a proposed band−pass filter is 0.102 dB and 0.103 dB. Additionally, the return loss of a proposed band−pass filter is 19.13 dB and 19.96 dB, respectively. The bandwidth of a filter is 120% and 105%, respectively. The size of the filter is 0.0708 λg × 0.0533 λg. The designed filter has a good skirt phenomenon, small size, low insertion loss, and dual−band characteristics.

Design and implementation of a smart elderly positioning management system based on wireless communication network

Wireless communication refers to long-distance transmission communication between multiple nodes without propagation through conductors or cables, and wireless communication can be carried out by radio and electromagnetic waves, etc. Judging from the current situation, the home space positioning design of the medical and elderly care communities is not perfect, which affects the traditional home care. Wireless communication can give wisdom, coordination, and development space in the smart elderly care space positioning design, allowing the elderly to interact, contact, and know their precise location and behavior. This article mainly studies the design and implementation of smart pension space positioning under BIM technology. This paper introduces the frontier of Internet-of-things technology and the theory of sensor network topology control. It uses basic IoT technology to implement the "point, line, and surface" combination of personnel placement algorithms, sensor network communication protocols, topology checks, security models, sensor network wireless communication units, and wireless communication technology. The basic technology and communication technology of personnel deployment based on BIM technology are introduced, the development strategy of wireless communications node is studied, the installation of equipment radio personnel and communication equipment is designed, and the system management platform for the design and development of staff placement in pension institutions is provided. The Web site's information service management, standardized procedures, optimized services, provision of information, intelligent management, and pension services. The experimental results of this paper show that the smart pension space positioning under the BIM technology solves the management loopholes in nursing homes, shortage of nursing staff, inefficiency, lack of services, and family conflicts. It improves the efficiency of the elderly by 25% and the safety index by 23–27%. The development of wireless communication technology promotes the development of intelligent pension space. It will be an important future development direction for the smart community pension.

An intelligent face mask integrated with high density conductive nanowire array for directly exhaled coronavirus aerosols screening

The current ongoing outbreak of Coronavirus Disease 2019 (COVID-19) has globally affected the lives of more than one hundred million people. RT-PCR based molecular test is recommended as the gold standard method for diagnosing current infections. However, transportation and processing of the clinical sample for detecting virus require an expert operator and long processing time. Testing device enables on-site virus detection could reduce the sample-to-answer time, which plays a central role in containing the pandemic. In this work, we proposed an intelligent face mask, where a flexible immunosensor based on high density conductive nanowire array, a miniaturized impedance circuit, and wireless communication units were embedded. The sub-100 nm size and the gap between the neighbored nanowires facilitate the locking of nanoscale virus particles by the nanowire arrays and greatly improve the detection efficiency. Such a point-of-care (POC) system was demonstrated for coronavirus ‘spike’ protein and whole virus aerosol detection in simulated human breath. Detection of viral concentration as low as 7 pfu/mL from the atomized sample of coronavirus aerosol mimic was achieved in only 5 min. The POC systems can be readily applied for preliminary screening of coronavirus infections on-site and may help to understand the COVID-19 progression while a patient is under prescribed therapy.

Smart contact lens and eyelid patch

Materials Science Although chronic ocular surface inflammatory diseases are prevalent, appropriate devices to monitor the disease condition quantitatively in daily life have not yet been developed. Point-of-care devices for controlled therapy in response to biosensing are also not available. Jang et al. report wearable devices for the monitoring and treatment of ocular surface inflammation. A smart contact lens using graphene biosensors integrated with wireless communication units monitors a biomarker of ocular inflammation and sends data wirelessly to a mobile device. A transparent skin patch mounted on the eyelid provides feedback thermotherapy, which is controlled by the mobile device through wireless communication. In vivo applications to animal and human subjects confirmed the potential of this wearable health care platform. Sci. Adv. 10.1126/sciadv.abf7194 (2021).

Rainfall Induced Landslide Monitoring System

Landslides are one of the natural or construction-triggered events that often occur throughout the world. These events cannot be eliminated but the effects like deaths or injuries, monetary losses, economic disruption, and so on, can be minimized. Early warning systems for landslide majorly rely on sensor nodes that evaluate geological and geotechnical soil characterization. In order to monitor the changes, smart sensors, fast computing units are required but nowadays merging with the internet of things technology, the system will store useful data in the cloud. Internet of things is already recognized as the next revolutionary technology that connects devices and makes the system smarter. Physical quality generating data and these systems are designed to monitor and send further to the cloud to make an adequate application. Accelerometers are used to monitor mass movements, moreover low cost, and low power customized AVR microcontroller with a Wi-Fi board designed to store data in the cloud. Internet of Things based customized board does not require much space for installation. This paper presents a novel design equipped with four tri-axial sensors, a power supply, and a wireless communication unit.

Multi-layer multi-rate model predictive control for vehicle platooning under IEEE 802.11p

Vehicle platooning has gained attention for its potential to increase road capacity and safety, and higher fuel efficiency. Platoon controls are implemented over Vehicle-to-Vehicle (V2V) wireless communication, in-vehicle networks and Electronic Control Units (ECUs). V2V communication has a low message rate imposed by the V2V standard compared to the rate of modern in-vehicle networks and ECUs. The platoon control strategy should take into account such multi-rate nature of the implementation architecture for higher performance. Current literature does not explicitly consider such real-life constraints. We propose a two-layered control framework for vehicle platoons wirelessly communicating complying with the industrial standard IEEE 802.11p. In the upper-layer, vehicles receive state information from the immediate preceding vehicle over a control channel at 10 Hz under the IEEE 802.11p standard with occasional packet drops. Using such information and the vehicle state information, the engine control system, i.e.the lower-layer, realizes the desired vehicle state (e.g., acceleration) over the fast and reliable in-vehicle networks (e.g., FlexRay, Ethernet). In this work, a distributed model predictive control framework is proposed for the upper-layer targeting a Predecessor-Follower (PF) topology. A state-feedback control scheme is proposed for realizing the desired vehicle states for the lower-layer. Our framework minimizes the inter-vehicle distance and the tracking error enforcing collision avoidance and robustness against packet drops at the upper-layer. We validate our algorithm in simulation using our co-simulation framework CReTS and on an embedded platform, developed by Cohda Wireless and NXP, running in real time and communicating through the IEEE 802.11p standard. With extensive simulations and experiments, we evaluate the performance and feasibility of the proposed framework under a number of practical constraints. Our approach is a step towards the implementation of platoon control in reality.

Design and experimental study of the remote control for a novel patient transfer apparatus

This paper introduces the design of the remote control for a novel patient transfer apparatus. First, the overall design of the control system is put forward based on the working principle, and design requirements of the apparatus. Second, voltage regulator circuit of the remote control based on the MC34063 is designed to fit for the OLED displayer, parameters such as the filter capacitor have been determined. Next, wireless communication unit adopted CC1110 and the communication instruction code is introduced. Then, the interaction interface of the remote control is finished to facilitate the implementation of the adjustment functions. finally, a simulation and a real experiment has been completed, it indicates the correctness of the voltage regulator circuit and the effectiveness of the remote control respectively.

A testability allocation method suitable for engineering application

Firstly introduces the commonly used distribution methods of testability in engineering, and points out that the existing distribution methods have poor operability and inconvenience.A new method of assigning testability index according to failure rate is proposed. This method uses the undetectable rate and the unisolated rate to distribute the primary testability index. Then according to the data obtained in the designer’s design, the secondary distribution is carried out in combination with the reliability index and data. This method not only improves the implementability of testability allocation, but also harmonizes the relationship between testability allocation and reliability allocation. Finally, an airborne wireless communication unit is taken as an example to verify the feasibility and effectiveness of this method.

Hybrid PDMS-TiO2-stainless steel textiles for triboelectric nanogenerators

• Electrophoretic deposition is employed to prepare hybrid textiles for tTENGs. • The tTENG possesses V oc ~ 110 V, I sc ~ 30 μA, Q ~ 9nC and P ~ 1.05 W m −2 . • Real-time biomechanical energy harvesting is realized on the worn tTENG. • A wireless communication via infrared rays is achieved by the wearable tTENG. Electrophoretic deposition is employed to deposit flower-like TiO 2 (F-TiO 2 ) particles onto stainless steel textiles to obtain a Fe@F-TiO 2 /PDMS hybrid textile as the negative tribo-material. The electrophoresis process enables adjustable deposit amounts and three-dimensional and uniform deposits of flower TiO 2 . The textile triboelectric nanogenerators (tTENGs) fabricated from the Fe@F-TiO 2 /PDMS hybrid textile working in conjunction with cotton and silk exhibit excellent performances. The tTENG generates a voltage of 120 V, a current of 25 μA and an output power of 0.85 W m −2 with the cotton and 110 V, 30 μA and 1.05 W m −2 with the silk. The flower-like TiO 2 is significant for the high performance of the tTENG, being attributed to the tailored surface and improved permittivity. Wearable tTENGs exhibit good durability after 8,000 cycles and power 58 light emitting diodes. By utilizing the worn tTENG, real-time biomechanical energy harvesting is realized; furthermore, a wireless communication via infrared rays is achieved, confirmed by the successfully receiving of the wireless signal and lighting up of the indicator LED. This work demonstrates high-performance hybrid textiles prepared by electrophoretic deposition and tTENGs for applications in wearable real-time energy harvesters and wireless communication units.

Remote control device to control the contact uniformity of the brush strippers on the spindle’s surface of the cotton picking apparatus

In this paper, the question of implementation remote control of contact uniformity of brush strippers on a spindles surface of the harvest device of the mechanical cotton picker is considered. A brief analysis of known works is carried out and the urgency of the development of a specialized remote control system for the rotation speed of brush strippers and the uniformity of touching the brush strips on the surface of the spindles is substantiated. As a sensing element, it is proposed to use a strain gauge that changes its ohmic resistance when the stripper brush touches the spindle surface. A wireless GSM communication unit is used for remote transmission and reception of information.

Autonomous Detection for Traffic Flow Parameters of a Vehicle-Mounted Sensing Device Based on Symmetrical Difference

Based on the research and analysis of traffic detectors, it is found that the existing vehicle detection equipment is generally vulnerable to environmental interference and the detection effect cannot meet the current traffic demand. Therefore, an automatic detection method of traffic flow parameters based on symmetrical difference was put forward. This method collects the traffic flow parameters through wireless sensor nodes. Since the safety transmission protocol of VANET (Vehicular Ad Hoc Networks) can maximize the safety channel capacity, it transmits the traffic flow parameters to the data acquisition and control equipment of the upper computer through the cross layer pre-balanced safety transmission protocol of VANET in the wireless communication unit. The data acquisition and control equipment of the upper computer uses the traffic flow detection method based on the symmetrical difference to obtain the details of the moving objects in the traffic flow so as to realize the independent detection of the traffic flow parameters of the vehicle-borne sensor equipment. Experimental results show that the designed method has anti-interference abilities for the noise and light changes. Meanwhile, this method can completely extract moving objects from the traffic flow and can improve the detection effect of the moving objects in the traffic flow. Thus, the effectiveness of the proposed method can be fully verified.

Kisműholdak fejlesztése a sokoldalúság és a könnyű reprodukálhatóság tükrében

A világűr mára már nem csak a gazdasági nagyhatalmak kiváltsága. A társuló technológia fejlődésének hatására bekövetkező költségcsökkenés eredményeképpen napjainkban akár egy kis cég, alacsony költségvetéssel is megmérettetheti magát a 21. század űrversenyében. Ehhez biztosítanak tökéletes platformot a nano- és mikroműholdak, amelyek alkalmazási lehetőségei folyamatosan bővülnek. Az egyre változatosabb hasznos terhek azonban értéktelenek a sokoldalú platformok és azok alapvető alrendszerei nélkül, mint például a fedélzeti számítógép, tápegység, kommunikációs egység vagy a műhold térbeli orientációjáért felelős alrendszer (Attitude Determination and Control System – ADCS). Így felmerül az igény egy olyan univerzális műholdplatform fejlesztésére, amelyben a létfontosságú alrendszerek biztosítva vannak különböző, harmadik fél által fejlesztett hasznos terhek, illetve tudományos kísérleti eszközök számára. Ezzel létrehozhatunk egy standardizált, költséghatékony és rugalmasan bővíthető, ezáltal még szélesebb körben elérhető kisműholdas platformot. A cikkben részletesen bemutatunk egy, a fentiekben leírt követelményeknek megfelelő univerzális CubeSatplatformot, kitérünk az egyedi mérnöki módszereket és megoldásokat igénylő fejlesztési folyamatokra, a nagy megbízhatóságú szoftvertechnológia előnyeire és a platform nyújtotta új lehetőségekre.

무선전력 전송효율 음영영역 제거와 최대효율 전송을 위한 3D 스캐닝 MR-WPT 시스템

This paper proposes a 3D scanning magnetic resonance wireless power transfer system to eliminate dead-zones and improve transmission efficiency. This system consists of an oscillator, power amplifier, microcontroller unit, personal computer, pan-tilt motor, transceiver coil, rectifier, and wireless communication units. This system provides the maximum voltage to the receiver within a short timeframe using the zone-based maximal transmission efficiency searching process algorithm. From the measurement results, it can be observed that the time to find the maximum transmission efficiency with this algorithm is 11 times faster than that of the full scan by 5° and that the position error of maximum transmission efficiency is less significant.