Amplitude Of Output Signal Research Articles

Utilizing Photovoltaic Solar Panels for Real‐Time Localization and Speed Detection of Approaching Illuminated Objects in Humanoid Robots

ABSTRACTIn the field of humanoid robotics, this paper showcases a promising method of integrating the photovoltaic (PV) solar panels into the “GUCnoid 1.0” humanoid robot model. Instead of the conventional power generation, solar cells are used to supply electrical energy to various sensors to create a system capable of real‐time sensing and perception. The main focus of the study will be the use of PV panels as receptors that are capable of detecting the light, enabling an adaptive system which perceives environmental changes. The behavior of the PV cell is superbly studied when various light sources are approached or depart. They finally reveal unique patterns in the voltage output signal amplitude. Interestingly, these patterns figure out the same symmetric structure, which reflects on a vertical axis by their mirroring. Using this simplicity, the method involves using an artificial neural network that is able to distinguish the light sources coming towards the detector and the ones running away and the rate at which they approach/recede. Outdoor experiment was organized for verification of methods. GUCnoid 1.0— humanoid robot was placed in front of a moving vehicle with different speeds of approach. To be able to identify the vehicle's position and velocity, a PV sensing technique has to be applied. This innovative technology will have wide applications, with much attention paid to improving the speed of finding nearby objects or vehicles in the scenarios where quick detection is a serious life safety issue. Through the process of PV solar panels' smart sensing, we directly connect the areas of high‐tech robotics and renewable energy. This discovery creates an opportunity for companies to build more responsive and flexible humanoid robots that can effectively collaborate with humans to achieve greater outcomes through more secure and efficient interactions between humans and robots.

Size effect in CoFeB-based anomalous Hall sensor and its applications in pulse detection

Anomalous Hall effect (AHE) sensor has attracted significant attention in recent years due to its simpler structure and better sensitivity as compared to semiconductor-based Hall sensors. However, up to now, most of the work has been focused on its basic functionalities, with very little attention given to optimizing its performance for practical applications. In this work, we systematically investigated how the lateral dimension affects the performance of CoFeB-based AHE sensors. By adjusting the sensor width while keeping the length and other parameters constant, it is found that although the output signal amplitude decreases with increasing the sensor width, the noise and power consumption also decrease simultaneously, leading to an overall enhancement of the sensor performances with a sensitivity, detectivity, and power efficiency of 8960 Ω/T, 205nT/Hz@1Hz, and 2009 V/WT, respectively. To illustrate the potential applications of AHE sensors, we demonstrate a proof-of-concept experiment to showcase the potential AHE sensor in pulse detection.

A single-IC realizable, electronically tunable, OTA-based full-wave rectifier with simultaneous positive and negative outputs

A new voltage-mode full-wave rectifier (FWR) is proposed in this study. The proposed FWR employs two single-output operational transconductance amplifiers (OTAs), four diodes, and two grounded resistors. It has high input impedance and does not need any extra bias current or voltage sources. It simultaneously provides positive and negative rectified output signals over separate output terminals. The amplitudes of both output signals can be adjusted by varying the resistor values or the transconductance (gm) values of the OTAs. It does not include any floating passive elements, so it is suitable for integrated circuit (IC) implementations. The proposed FWR can be implemented by using a single commercially available IC such as LM13700. However, the proposed FWR has a single matching condition for gm values of the OTAs. Several simulation and experimental test results are added to confirm the theory and show the operability of the proposed circuit.

A modified Astable multi-vibrator-driven 3D chaotic circuit with Dual LC band stop filters

This work describes a proposed circuit design with three essential parts: an Astable Multi-vibrator (ASMV) source producing a square wave as the driving signal, a two-stage LC band stop filter selectively attenuating frequencies with a focus on suppressing high-frequency components, and an integrator combining outputs from the second and third stages. Using two extra feedback channels, a standard ASMV gains the ability to change the duty cycle of the square wave, effectively altering the amplitude and duty cycle of the ASMV output signal. The LC band stop filter is vital for reducing or blocking frequencies close to 650 Hz and allowing other frequencies to predominate in the signal. The output frequency of the proposed circuit is governed by its specific parameters and frequency response characteristics. The suggested three-dimensional chaotic circuit produces dynamic, complex chaotic attractors with a simple circuit complexity. The differential equations describing the circuit’s functioning were checked using MATLAB. Circuit working was verified using Keysight ADS simulation and validated by experimental measurement. The randomness of the state variables are verified using the NIST test.

Solar-blind ultraviolet emission-detection monolithic integration of AlGaN multiple-quantum-well diodes via concentric ring-circle configuration

AlGaN multiple-quantum-well diode-based solar-blind ultraviolet emission-detection monolithic integration system shows great application value due to its advantages of multifunctionality, secure communication, and anti-interference ability. To reduce the lateral optical propagation loss and improve the emitting light detection efficiency, we have proposed a concentric ring-circle configuration for the system, where the out-ring light-emitting diode is the emitter at 253 and 267 nm, and the inner-circle detector is the receiver. The out-ring light-emitting diode exhibits about twice the injection current at the same bias and slightly higher light output power at the same current due to better current spreading and sidewall light extraction compared to the conventional square–square configuration. Simultaneously, the concentric inner-circle detector maximizes the collection of the emitted light flux. Under the emission-detection mode for the monolithic integration system, compared to the conventional square–square configuration, the concentric ring-circle design presents an improvement in the ratio of emitter injection current to detector output photocurrent and higher output signal amplitude under the same transmission work mode, demonstrating the improved system energy and coupling efficiency. This design provides a potential approach to achieve low power consumption and high bandwidth in the monolithic integrated optoelectronic chips.

Development of Second Order High Frequency Filter for Partial Discharge Measurement

Partial discharge (PD) can occur on any high-voltage equipment. This study is particularly concerned with the PD that occurs on underground cables. Researchers frequently struggle to isolate interference noise from the PD signal when doing PD measurements. Therefore, to reduce the interference noise during PD measurements, Sallen-Key high-pass filters with a 500 kHz, or a little bit higher cut-off frequency are designed. This filter is designed with a designated cut-off frequency value because the frequency range of the PD signal is between 1 MHz to 1 GHz. Based on the results of experimental testing for actual filters, the designed filter is a high-pass filter with a cut-off frequency of 500KHz. When the generator function's input frequency values are set between 500 kHz and 2.4 MHz, the signal will pass the filter and provide output values for both frequencies and amplitude. However, at frequencies lower than 500 kHz, the signal is beginning to be filtered and the output signal's amplitude is getting close to zero. Based on the PD testing results, there is interference on the PD signal shown on the oscilloscope when a 1kV supply is applied to an underground cable without using a filter. But, when the proposed filter is used in PD testing, the ripple voltage is reduced from 123 mV to 67 mV. This proves that when the designed filter is used in PD testing, it can reduce interference noise on the PD signal.

Phase noise of signal generators with multichannel digital synthesizers

Wide use of a direct digital synthesizer (DDS) and digital to analog converters (DAC) in digital antenna arrays permits for fast modulation parameters variations and beam positioning, and also improves the quality of beam forming due to high accuracy of signal generation. However, any systematic and random phase deviations of array channels not only lead to distortion of radiation pattern but also cause deterioration of signal processing at receiver end. Phase noise is one of critical parameters of such systems. Traditional theory and empirical methods assumes small or zero phase deviation of phase of channel output signal when combining these signals. We have proposed the model in which coupling of AM and PM noise persists for any arbitrary phase deviation of channels in multistage circuits comprising multichannel digital synthesizers. Absolute phase noise measurements of combined DACs outputs for zero phase offset and antiphase modes with two values of DAC output signal amplitude difference permit for estimation of residual phase noise of DAC and clock receiving and distribution circuitry and demonstrate good compliance of results of calculation.

Wearable patterned single electrode-based triboelectric nanogenerator for peak-encoded interface

Advancement in human-machine interface (HMI) is indispensable for development of virtual/augmented reality, robotics control, and artificial intelligence (AI). However, there lack a simple facile electronics to achieve accurate finger motion recognition and remote robot control through simple signal processing. Herein, a wearable patterned single electrode-based triboelectric nanogenerator (PS-TENG) based on regenerated silk film (rSF) is developed for peak-encoded interface, which can accurately identify the handwritten numbers or letters. The patterned single electrode, composed of nine units with five different patterns, is successfully constructed by ink-jet printing Ag inks on the rSF. When handwriting on the PS-TENG, the generated output voltage with different peak amplitude can be transformed into a peak spectrum with spatial information. Handwriting numbers or letters can be accurately identified through simple digitization data processing of the peak-encoded spectrum without complex algorithms. Furthermore, the PS-TENG as peak-encoded interface enables precise game play, accurate pattern lock, and wireless robot control. Importantly, based on relative amplitude of output signals, the peak-encoded code is regardless of factors including absolute amplitude of output signals, sliding speed and environmental humidity. Consequently, the PS-TENG, characterized by self-powered feature, simple structure and straightforward signal processing, demonstrates remarkable identification accuracy of handwritten numbers and letters through decoding unique and stable peak spectrum, which would have great potential in the field of virtual control panels, HMI and AI.

Unveiling the principles of stochastic resonance and complex potential functions for bearing fault diagnosis

This paper introduces a novel and complex Unsaturated Piecewise Linear Quad-Stable Stochastic Resonance System (UPLQSR) to address the issue of output saturation in the Classical Quad-Stable Stochastic Resonance (CQSR) system. By linearizing the structure of the potential function, the constraints imposed by high-order terms are effectively eliminated, allowing Brownian particles to move more freely. Numerical simulations demonstrate that UPLQSR achieves significantly higher output signal amplitudes compared to CQSR, highlighting its remarkable signal amplification capability. By analyzing the structure of the potential function, the relationship between the height of the potential barrier and the aggressiveness of the particles jumping is determined. Utilizing adiabatic approximation theory, the paper derives the Steady-state Probability Density (SPD), Mean First Passage Time (MFPT), and Spectral Amplification (SA), revealing the specific process of the particle jumping, as well as the influence of the parameters on the performance of the UPLQSR. After optimizing parameters using the Adaptive Genetic Algorithm (GA), UPLQSR is applied to the early fault diagnosis of various bearing models under Gaussian white noise, demonstrating superior fault detection capabilities. In summary, this study pioneered the theory of non-saturation of quad-stable systems, optimized the weak signal detection technique, and provided a more accurate means of signal identification and analysis, highlighting its great value of application in engineering.

Research on discharge process of Bi2Te3 module under different thermal stimulation conditions

In the actual working process, the working environment temperature of the thermoelectric device is constantly changing, and rarely remains stable, a thermoelectric device is composed of more than one thermoelectric module monomer (PN junction), each of which can be used as an independent research object. To address this issue, the thermoelectric properties of thermoelectric modules (p, n-type Bi2Te3) are measured under different temperature environments. A self-constructed thermoelectric performance test platform, an infrared thermal imager, and a voltage acquisition system are used to monitor different temperature difference conditions in real-time. A transient discharge evaluation model was established to calculate the real-time discharge amplitude of the thermoelectric module based on its temperature gradient distribution. The results show that the error of the transient discharge evaluation model is about 5%, which is reliable. For large-sized thermoelectric modules, the maximum discharge amplitude under open circuit voltage can be obtained solely based on the overall temperature gradient of the thermoelectric module; the amplitude of the electrical output signals increases uniformly when the temperature difference between the two ends of the module is increasing uniformly; and the stable electrical output signals are also produced at both ends of the module when the temperature difference is stabilized. After stabilization, when the temperature drops uniformly, the amplitude of the electrical output signal decreases uniformly. In the range of T = 298–573 K, the greater the temperature difference between the two ends of the thermoelectric module is, the greater the amplitude of the stabilized electrical output signal is; and vice versa. The greater the rate of thermal loading, the faster the increase in the amplitude of the electrical output signal at both ends of the thermoelectric module. This also reduces the time needed to reach steady state equilibrium, enabling the thermoelectric module to produce a stable electrical output earlier than individual p and n-type Bi2Te3 modules.

Propagation of electrical signals by fungi

Living fungal mycelium networks are proven to have properties of memristors, capacitors and various sensors. To further progress our designs in fungal electronics we need to evaluate how electrical signals can be propagated through mycelium networks. We investigate the ability of mycelium-bound composites to convey electrical signals, thereby enabling the transmission of frequency-modulated information. Mycelium networks were found to reliably transfer signals with a recoverable frequency comparable to the input, in the 100Hz to 10 000Hz frequency range. Mycelial adaptive responses, such as tissue repair, may result in fragile connections, however. While the mean amplitude of output signals was not reproducible among replicate experiments exposed to the same input frequency, the variance across groups was highly consistent. Our work is supported by NARX modelling through which an approximate transfer function was derived. These findings advance the state of the art of using mycelium-bound composites in analogue electronics and unconventional computing.

A non-invasive method of glucose monitoring using FR4 material based microwave antenna sensor

Abstract This work presents a unique non-invasive method for monitoring glucose levels in blood using a planar Yagi–Uda antenna as a microwave sensor. The proposed antenna, operating at 5.5 GHz, exhibits a directional radiation pattern with a peak gain of 6.74 dBi. A low-cost FR4 material of size 30 mm × 40 mm × 1.6 mm is used as a dielectric substrate. A human finger phantom, comprising layers of skin, fat, blood, and bone, is created at 5.5 GHz in EM simulation tool for mimicking a real human finger. The finger phantom is positioned at different locations around the antenna and corresponding frequency shifts are remarked to a variation in glucose concentration from 0–500 mg/dL. An exemplary frequency shift of maximum 26 MHz is recorded when the phantom is placed at the bottom of the antenna. Time domain analysis is also carried out to understand the effect of glucose concentration variation on the output signal amplitude and delay. Simulated antenna results are found to be in stupendous agreement with the measured results. An experiment of placing a real human finger around the fabricated antenna also presents a splendid correspondence with the simulated results. Hence, this mechanism can be expedient for monitoring glucose levels in blood.

A novel oven structure for improving temperature uniformity of vapor cell in atomic sensors

Alkali-metal vapor cells are key elements of atomic sensors. The temperature uniformity in the vapor cell is important for the sensitivity of the atomic sensors especially highly-sensitive SERF atomic magnetometers. This study proposes a novel double-layer cylindrical oven to improve the heating performance and the temperature uniformity of the vapor cell. We use the finite element method to build the thermal simulation models of the conventional square oven and the novel double-layer cylindrical oven. The performances of two ovens are compared. Then we build the experimental system to carry out the measurement experiment of heating temperature of the conventional and novel ovens and the in-situ measurement experiment of temperature distribution of the vapor cell using different ovens. We also measure the change of output signal amplitude of the SERF atomic magnetometer with frequency, i.e. the frequency response R(f) using the conventional and novel ovens respectively to evaluate the performance of the SERF atomic magnetometer using different ovens. The experimental results demonstrate that the proposed oven structure can improve the temperature uniformity of the alkali-metal vapor cell by 63.63% and the amplitude of R(f) using the novel oven increases by 24.7% on average. The novel double-layer cylindrical oven improves the temperature uniformity in the alkali-metal vapor cell and increases amplitude of the output signal of the SERF atomic magnetometer. The study is of great significance for improving the sensitivity of the atomic sensors especially SERF atomic magnetometers.

Numerical and experimental study on monitoring coal cracks with PZT sensor

The rupture of coal pillar can lead to spontaneous combustion or collapse of goaf, which endangers the safety of workers. To explore the relationship between the crack depth of the coal structure and the signal received by the piezoelectric ceramic sensor, the output data of coal samples were analyzed by using the piezoelectric effect, combined with the experiment and ABAQUS simulation. Based on the signal amplitude, the output signal characteristics of the coal model with different crack depths were analyzed, and the evaluation index of coal crack cracking degree (Dc) was defined. The results show that the piezoelectric fluctuation method can effectively identify the local cracks of coal. When the distance between the lead Piezoelectric Transducer (PZT) patch and crack position is constant, the amplitude of the PZT patch output signal will decay with the deepening of the crack depth, while the value of increases with the increase of crack depth. This study provides a theoretical basis for mine disaster prevention and control.

Numerical Study of Acoustic‐Electric Signal Conversion for GIS Discharge Detection and Structure Optimization for pMUT

With the development of microelectromechanical technology, the piezoelectric micromechanical ultrasonic transducer (pMUT) for ultrasonic detection of gas‐insulated switchgear (GIS) breakdown discharge has become possible. In this article, the ultrasonic‐solid‐pMUT coupling simulation model was established to investigate the propagation process of ultrasonic waves in GIS enclosure and the conversion between ultrasonic and electric signals through pMUT. The output electric signals for the unsimplified top electrode and simplified top electrode model were compared, and the structure of receiving pMUT was optimized according to the main ultrasonic frequency range of GIS breakdown discharge and the key performance parameters of pMUT. First, it is found that the simulation results of the ultrasonic‐solid‐pMUT coupling model are reliable, and the frequency of the output electric signal of receiving pMUT is consistent with the input signal, while the amplitude of output signal attenuates greatly. Second, simplifying the top electrode of pMUT may lead to relatively large errors in simulation results. The output response of simplified pMUT is obviously weakened, and the inherent frequency is higher. Furthermore, it is noted that the pMUT inherent frequency (f0) is inversely proportional to the radius (R) of the piezoelectric layer and directly proportional to the substrate thickness (dsi). When the coverage rate of the top electrode is between 30% and 80%, the pMUT effective electromechanical coupling coefficient () is high and has a maximum value. Finally, it is indicated that the pMUT with the optimum structure is suitable for the detection of GIS breakdown discharge ultrasonic signals, and the can be improved by 106.7%.

Low-Voltage Intrinsically Stretchable Organic Transistor Amplifiers for Ultrasensitive Electrophysiological Signal Detection.

Stretchability is a prerequisite for electronic skin devices. However, state-of-the-art stretchable thin-film transistors do not possess sufficiently low operating voltages and good stability, significantly limiting their use in real-world biomedical applications. Herein, a van der Waals-controlling elastomer/carbon quantum dot interfacial polarization methodology is proposed to form a hybrid polymer dielectric with 620% tensile strain and large-area film uniformity (>A4 paper size). Using the hybrid polymer dielectrics, the prepared intrinsically stretchable organic thin-film transistors demonstrate a low operating voltage below 5V, 100% strain tolerance, and excellent operational stability, as well as a high on-current/off-current ratio of 105 and a steep subthreshold slope of 500mV dec-1 . Based on this device technology, an amplifier with a high gain of 90V V-1 among the highest values of reported stretchable transistors is realized. This amplifier is at the first time applied to detect human electrophysical signals with an output signal amplitude of over 0.2V, which even outperforms other types of the state-of-the-art organic amplifiers for human electrophysiology monitoring. This stretchable device technology sufficiently meets the safety and portability requirements of wearable biomedical applications, opening a new opportunity to e-skin with signal control and amplification capabilities.

Novel Neuron-like Procedure of Weak Signal Detection against the Non-Stationary Noise Background with Application to Underwater Sound

The well-known method of detecting a useful signal in the presence of noise during underwater remote sensing, based on the matched filtering of the received signal with the test signal, provides the maximum signal-to-noise ratio (SNR) at the receiver output. To do this, a correlation-type criterion function (CF) is constructed for the received and test signals. In the case of large volumes of processed data, this method requires the use of large computing resources. The search for a data processing method with lower computational costs, as well as the effective application of artificial neural networks to array signal processing, motivates the authors to propose an alternative approach to the CF construction based on the McCulloch–Pitts neuron model. Such a neuron-like CF is based on a specific nonlinear transformation of the input and test signals and uses only logical operations, which require much less computational resources. The ratio of the output signal amplitude to the input noise level is indeed the maximum with matched filtering. Studies have shown that it is not this parameter that should be considered, but statistical characteristics, on the basis of which the thresholds for detecting a signal in the presence of noise are determined. Such characteristics include the probability density distributions of correlation and neuron-like CFs in the presence and absence of noise. In this case, the signal detection thresholds will be lower for the neuron-like CF than for the conventional correlation CF. The aim of this research is to increase the accuracy of the selection of a useful signal against the intense noise background when using a processor based on the neuron-like CF and to determine the conditions when the input SNR, at which signal detection is possible, is lower compared to the correlation CF. The comparative results of stochastic modeling show the effectiveness of using a new neuron-like approach to reduce the detection threshold when a chirp signal is received against a background of unsteady Gaussian noise. The advantages of the neuron-like method become significant when the statistical distribution of the additive noise does not change, but its variance increases or decreases. In order to confirm the presence of non-stationarity in real noises, experimental data obtained from the remote sounding of bottom sediments in the Black Sea are presented. The results obtained are considered to be applicable in a wide range of practical situations related to remote sensing in non-stationary environments, long-range sonar and sea bottom exploration.

Thermoelectric Response Characteristics of Bi2Te3 Based Semiconductor Materials

Abstract In actual operation, the operating environment temperature of thermoelectric devices are constantly changing and rarely remain stable, and the electrical output characteristics of thermoelectric devices are largely determined by thermoelectric materials. In response to this question, the thermoelectric properties of thermoelectric materials (p and n type Bi 2 Te 3 {\mathrm{Bi}_{2}}{\mathrm{Te}_{3}} ) are measured under different temperature difference environments. The Seebeck coefficient, resistivity, and thermal conductivity of the specimens at T = 300 – 600 K T=300\text{--}600\hspace{0.1667em}\text{K} were measured by CTA-4 and CLA1000 (laser flash method), respectively; the thermal and electrical output responses of the thermoelectric materials under different temperature difference conditions were collected in real time by using a self-built thermoelectric performance test platform, thermal/electrical test system with infrared thermal imager, and voltage acquisition system, respectively. The experimental results show that when the temperature difference between the two ends of the specimen increases uniformly, the electrical output signal amplitude also increases uniformly; when the temperature difference is stable, the two ends of the specimen also produce a stable electrical output signal. After stabilization, the electrical output signal amplitude also decreases uniformly when the temperature decreases at a uniform rate. In the temperature range of 298 ∼ 573 K 298\sim 573\hspace{0.1667em}\text{K} , the larger the temperature difference between the two ends of the specimen was, the larger the amplitude of the electrical output signal was after stabilization; and vice versa. The greater the loading rate of the thermal load was, the greater the rate of increase of the electrical output signal amplitude at both ends of the specimen was, and the steady-state equilibrium time required was less.

SIMULATION CHAOTIC DYNAMICS OF RELATIVISTIC BACKWARD-WAVE OSCILLATOR WITH USING CHAOS THEORY AND QUANTUM NEURAL NETWORKS

Nonlinear simulation and forecasting chaotic evolutionary dynamics of such complex system as relativistic backward-wave oscillator is treated using the new combined method, based on the chaos theory algorithms, concept of geometric attractors, and algorithms for quantum neural network simulation. It has been performed modelling the dynamics of multilayer photon echo neural network for the case of noisy input sequence. It has been performed analysis, modelling and processing the temporal dependence of the output amplitude for the backward-wave oscillator, described by system of the nonstationary nonlinear theory equations for the amplitude of electromagnetic field and motion of a beam. The data on the Lyapunov’s exponents, Kolmogorov entropy, correlation coefficient between the actual and neural networks prognostic rows, referred to a temporal dependence of the output signal amplitude of the nonrelativistic (relativistic) backward-wave oscillator are listed. The combining the advanced algorithms of the modern chaos theory, concept of a compact geometric attractors and one of the effective neural network algorithms, or, in a more general using an effective model of artificial intelligence etc, could provide very adequate and quantitatively correct description of temporal evolutionary dynamics of most complicated systems, in particular, in the field of modern ultrahigh-frequency electronics

Partial Discharge Detection and Sensitivity Improvement for Bushing Based on Optical Interference Technique

Bushing plays a significant role in insulation and mechanical support for power transformers. Its working state is closely related to the reliable operation of power transformers. To overcome the electromagnetic interference and security risks during sensor installation, a Sagnac interference optical technique for partial discharge (PD) detection is proposed in this paper. By establishing a simulation model of the sensing structure, it is verified that output signal amplitude varies periodically with the length of sensing and delay fibers. Moreover, the output value decreases with increasing probe radius. The results show that a delay fiber of 1.5 km, a sensing fiber of 3 m, and a bending radius of 5 mm are optimal parameter combinations to detect PD in a 72.5 kV defective bushing. In addition, consistent detection waveforms induced by both internal and external defects are obtained by the optical sensor and high frequency current transformer (HFCT) simultaneously, then the effectiveness of the optical sensor on detecting PD signals for bushing is verified. It is of great help to carry out online monitoring of bushing insulation defects through optical non-destructive installation.