Control Port Research Articles

Simulation analysis and experimental research on static performance of water-hydraulic pressure difference control valve

Many hydraulic tools, like hydraulic cylinders and hydraulic artificial muscle joints are operated by adjusting pressure differences between different zones. Typically, the method employed to change the pressure difference is establishing hydraulic bridges and adjusting liquid resistance. While effective, this method's drawback is complex structures. To address this issue, a water-hydraulic pressure difference control valve, integrating two hydraulic bridges, was designed. The static performances including the output pressure difference, the flow rate and the force acting on the valve core were analyzed using AMESim and computational fluid dynamics simulations. Based on the simulation results, a prototype of voice coil motor direct drive pressure difference control valve was manufactured and the corresponding experiments were carried out. The computational fluid dynamics simulation results show that the internal leakage and the through-flow capacity difference between throttling grooves affect the flow field characteristics of the valve. When the pump pressure is 3 MPa and the valve opening is at the middle position, the internal leakage increases the flow rate from 2.25 L/min to 2.38 L/min, and the through-flow capacity difference reduces the control port pressure from the theoretical analysis of 1.5 MPa–1.41 MPa. Furthermore, combined with the analysis of the external liquid resistance, the AMESim model of the pressure difference control valve is modified. When the pump pressure is 3 MPa, the pressure difference and flow rate average deviations between the modified AMESim model and the experiment are 0.021 MPa and 0.048 L/min. Finally, a rotational angle experiment for a water hydraulic artificial muscle joints showed satisfactory control effects, suggesting the valve's application in controlling hydraulic tools and actuators.

Investigation of metal-insulator-metal waveguides with elliptical-nanodisk resonator for high contrast ratio all-optical logic gates

Abstract This research focuses on the design and analysis of all-optical Exclusive OR(XOR), NOT, and OR logic gates based on metal-insulator-metal waveguides with elliptical-nanodisk resonators. The functionality of the proposed optical logic gates is determined by constructive and deconstructive signals which are applied to the input ports and control ports. To show the logic 0 (low) and logic 1 (high) output states, the limit of threshold transmission is 1.775 × 10−13 ∼0. The transmission (T) and contrast ratio (CR) are obtained to present the performance of the optical logic gates via the method of finite-difference time-domain. The maximum transmission is reached for the OR gate as 1.38 and the highest contrast ratio is 124.75 dB for the XOR and NOT logic gates. The designed logic devices are promising for improving more efficient optical signal information processing devices.

A Design Proposal Using Coherently Radiating Periodic Structures (CORPSs) for 2-D Phased Arrays of Limited Scanning

New configurations of 2-D phased arrays are proposed in this paper for reducing the number of phase shifters. This design methodology is based on the use of a novel coherently radiating periodic structures (CORPSs) block for 2-D phased arrays. Two new antenna systems for 2-D phased arrays are studied and analyzed utilizing the CORPSs blocks of four inputs and nine outputs. These CORPSs feeding blocks are applied in a smart way to feed the planar antenna arrays by generating the required phase plane and reducing the number of control ports. Interesting results are provided based on the experimental measurements and full-wave simulations. These results illustrate a great reduction of the active devices (phase shifters), providing a good design compromise in terms of the scanning range and side lobe level performance. Furthermore, the provided results illustrate a maximum reduction capability in the number of phase shifters of 81%, considering a scanning range of ±30° in azimuth and ±30° in elevation. A raised cosine distribution is applied to reach side lobe levels of −19 dB for ±18° and −17 dB for ±30° in elevation. These benefits could be of interest to designers of phased antenna systems.

Smooth control strategy for emergency switching of multi-port flexible interconnected distribution system modes

IntroductionWith the rise of distributed energy resources, the interconnection of distribution networks and Flexible Multi-State Switch (FMSS) has become a key technology in the construction of new distribution networks. FMSS plays a significant role in enhancing the reliability and flexibility of the system.MethodsThis paper investigates the impact of mode-switching in FMSSs on voltage shocks, current shocks, and power fluctuations in the event of a feeder fault in a multi-port flexible interconnected distribution system. Firstly, an improved state-tracking control method is proposed to effectively mitigate these impacts. Secondly, for feeder faults connected to the fixed DC bus voltage (Udc-Q) control port, a reselection method for the Udc-Q control port at the main station is introduced, aiming to select the optimal port to maintain the stability of the DC bus voltage.ResultsSimulation experiments have validated the effectiveness of the proposed control method in reducing voltage and current shocks as well as power fluctuations. Additionally, the proposed control strategy has demonstrated an enhancement in the safe and stable operation of the system under emergency fault conditions.DiscussionThe control strategy presented in this paper is capable of addressing the challenges posed by feeder faults and ensuring the stability of the DC bus voltage and reliable power supply to feeder loads, thereby enhancing the overall performance and reliability of the flexible interconnected distribution system. The research findings have been verified on the MATLAB/Simulink simulation platform.

Wideband 2×2 antenna-in-package based on magneto-electric dipole array antenna for 5G mmWave applications

This paper presents an antenna-in-package (AiP) design realised with the conventional multi-layer printed circuit board manufacturing method. The design consists of a wideband 2×2 magneto-electric dipole array antenna operating from 24.25−29.5 GHz and a wideband transition from the analogue beamformer integrated into the proposed MED array antenna (IMED). The IMED array antenna has been fabricated with two distinct NXP analogue beamformer chips, i.e., MMW 9004 KC and MMW 9002 KC covering the N257 and the N258 band, respectively. The measured effective isotropic radiated power at P1dB was 35.3 dBm and 35.1 dBm for the IMED with the MMW 9004 KC and the MMW 9002 KC analogue beamformer chip, respectively. Our proposed antenna demonstrates the feasibility of designing a single wideband AiP that can be integrated with different analogue beamformers operating within the frequency band of the proposed antenna. This is true, provided the RFIC used for integration has the same footprint for RF ports, serial peripheral interface control ports, and DC power supply ports. The primary benefit of the proposed technique is the design antenna can adapt the operating frequency to different frequency standards by incorporating additional analogue chips without increasing the design complexity. This feature enables the antenna manufacturer to tailor the antenna products to different frequency standardisations depending on where the antenna will be employed. The AiP operates at 5G millimeter-wave (mmWave) frequencies, with the potential for Internet of Things applications. Furthermore, from our simulation results, the proposed IMED can potentially be extended as a phased array antenna with 2D scanning.

Realization of all-optical logic gates using MIM waveguides and a rectangular ring resonator

In this study, all-optical OR, exclusive OR (XOR), NOR, XNOR, AND, NAND, and NOT logic gates using metal-insulator-metal (MIM) waveguides with a rectangular ring resonator are designed and analyzed. The structure has a silver plate with three input waveguides, one output waveguide, and a rectangular ring resonator. One of the input ports is used as a control port. The finite-difference time-domain (FDTD) method is utilized to obtain the optical spectrum of the proposed structures. To realize all-optical logic gate properties of the designed structures, optical signals with the same phase or different phases are passed through the waveguides. Transmission spectrum (T), contrast ratio (CR), and modulation depth (MD) parameters are obtained to determine the performances of all-optical logic gates. To determine the logic 1 (ON) and logic 0 (OFF) states of the output ports, the threshold transmission value is accepted as 0.23 for all-optical logic gates. For the proposed designs, the highest transmission, contrast ratio, and modulation depth values are 217%, 6.75 dB, and 100%, respectively. The structure also supports a data rate of 24 Tb/s. The designed optical logic gates have valuable features for developing high-performance optical devices.

Design of a nano-scale optical 2-bit analog to digital converter based on artificial intelligence

A novel, to our knowledge, optical 2-bit analog to digital converter (ADC) plasmonic waveguide was proposed using a metal–insulator–metal (MIM) with a circular disk resonator. A mutual cooperation between the finite element method of COMSOL software and MATLAB with the aid of artificial intelligence (AI) presented by the multi-layer perceptron (MLP) has been proposed for implementing the main structure. The phase shift difference between the input and the control ports is the basic principle used to select the outcomes on the output port. The transmission threshold (Tthreshold) is selected to be 0.5, resonance wavelength is 1040 nm, and the footprint of the design is 1200×2500nm. Several criteria like full width at half maximum (FWHM), contrast ratio (CR), modulation depth (MD), insertion loss (IL), and curves covering a complete wavelength range from 800 to 2000 nm versus transmission value (Tv) are simulated to evaluate the plasmonic system performance. The FWHM is 17 nm, CR is equal to 10.8 dB, MD and IL are 98.17% and −1dB, respectively, and the quality factor (Q-factor) for a single segment of the design reached 61.17.

Detection and quantification of wave trends in the Mediterranean basin

A study of a 42-year (1979–2020) long wave time series was performed for the Mediterranean Sea to detect and quantify trends in two relevant wave parameters adopted for coastal and offshore engineering purposes: significant wave height, Hs and peak period, Tp. The high resolution MeteOcean Re-Analysis database by the Department of Civil, Chemical and Environmental Engineering (DICCA) was used. At yearly and seasonal scales, the trends of the mean and maximum values were detected by the Mann–Kendall test, choosing a significance level equal to 90%. The slope or increase/decrease trends in Hs and Tp were assessed by the Theil–Sen estimator. For the mean values of Hs and Tp, increasing trends were detected for the Libyan, Levantine and Aegean seas, while for the maximum values this increasing trend was observed in a large part of the Mediterranean Sea. Finally, for the different marginal seas of the Mediterranean basin, a running trend analysis was applied in order to quantify the effect of the time window in the trend detection. The obtained results can be significant for flooding and erosion control strategies, ship and port operations, design and verification of structures, installations of Wave Energy Converters, in a hot spot for climate change such as the Mediterranean basin.

Design of Ultrasmall Plasmonic Logic Gates Based on Single Nanoring Dielectric-Metal-Dielectric Waveguide

This paper proposes a new configuration of dielectric-metal-dielectric (DMD) waveguides to design optical logic gates. Seven plasmonic logic gates, including NOT, OR, AND, NAND, NOR, XOR, and XNOR, are realized by one nanoring and four DMD plasmonic waveguides. To realize the logic gates, an ultrasmall size of 300 nm × 300 nm device is designed. The performance of the plasmonic logic gates is based on constructive and deconstructive interference between input and control ports. To evaluate the logic state of the output port, the threshold transmission limit is assumed to be 0.35. The transmission ratio, T, contrast ratio, CR, modulation depth, MD, insertion loss, IL, and contrast loss, CL, parameters measure the seven logic gates’ performance. A maximum T of 232% is obtained for AND, OR, and XNOR logic gates. Simulation results show that the dimensional parameters are optimized because of very high MD for all seven logic gates. Maximum values of CR and CL are obtained for the NOT gate. For the AND gate, a minimum IL value is achieved. The studied plasmonic logic gates can be employed in building blocks of all-optical signal-processing nanocircuits and nanophotonics devices. The finite element method (FEM) simulates the structure with COMSOL Multiphysics 5.4 software.

Low-cost Wireless Lamp Socket and Power Plug for Smart Homes and Its Comparison with Available Commercial Competitors

Smart home manufacturers widely produce Wireless Lamp Socket and Power Plug devices, which offer various features ranging from basic on/off control to more complex functionalities such as monitoring energy consumption, power losses, and harmonics. However, these devices tend to be expensive, as indicated by market surveys. To address this issue, the current study aimed to develop low-cost wireless control nodes for smart homes that operate using relays. The two nodes consisted of lamp socket and power plug built with lowcost electronic components, including a Wi-Fi built-in Microcontroller ESP8266 (Wemos D1 mini model) as the backbone to create ESP-Mesh wireless network and to provide control ports for high/low logic, a relay module, an AC-to-DC converter module, and terminals (E27 screw for lamp socket node and C-type plug for the power plug node). This paper primarily focuses on the hardware aspects. In order to evaluate the effectiveness of the nodes, the following tests are conducted: (1) product demonstration to assess the product functions, (2) power measurement in idle and active conditions, (3) ESP-Mesh connection testing, and (4) RSSI measurement. Functional testing is done using a smartphone with the UPISmartHome version 2.0 Android application, which successfully controlled the nodes wirelessly. In idle conditions, power plug and lamp socket nodes consume 426.36 mWatt and 418.275 mWatt of power, respectively. Further, in active conditions, power plug and lamp socket nodes consume 435.704 mWatt and 440.583 mWatt of power, respectively. RSSI testing results show that both nodes can be controlled within an optimal range of 60 meters (with reference to RSSI below –85 dBm) without the Internet, utilizing the ESP-Mesh feature of ESP8266. This range is deemed reasonable for smart homes of 21, 36, or 45 square meters. Both nodes could be controlled under the ESP-Mesh network that gets build. We also present the comparison with other products of competitors in this paper.

An Optimization Scheme and Circuit for Driving a Stepper Motor with the Index Control Mode

An optimized control scheme for driving a stepper motor with the index control mode is proposed and analyzed in this paper to control the stepper motor more accurately and effectively. Based on the built-in five-digit digital-to-analog signal converter (DAC), six stepper motor operating modes, namely 1/32 micro steps, 1/16 micro steps, 1/8 micro steps, 1/4 step, 1/2 step, and full step, can be selected. Only four control ports are required for switching of operating mode and motor steering. The simulation results show the optimized circuit can output accurate current signals to control the stepper motor.

Numerical simulation and experimental research on oscillation performance of disc-type jet oscillator

Based on active flow control technology, the two wall jets attached to a standard cylindrical surface due to the Coanda effect will output a detached jet when they collide. The direction of the output jets produced by this collision is very sensitive to small changes in the two wall jets. Therefore, a new type of curved-wall supersonic compressible disc-type jet oscillator is proposed by using the oscillating feedback jet as the source of wall separation. Through monitoring the internal flow field, the jet core’s pressure attenuation, the jet’s amplitude, and the wall pressure are analyzed. The results show that the disc-type jet oscillator model with a double-bend inlet has the best performance. After adding a multi-pipe outlet structure to the model, the oscillators with various disc diameters were simulated at different inlet pressures and air inlet frequencies to the wall-off control port. The oscillation performance of the disc jet oscillator is better when the diameter of the disc is 32 mm and 20 mm, and the included angle between the wall-off control port and the horizontal direction is 45°. Two kinds of oscillators of the same diameter as the model are experimentally studied, and the results prove the feasibility of the disc-type jet oscillator.

Nanoscale plasmonic combinational logic circuits based on an elliptical resonator.

The half-adder (HA) and half-subtractor (HS) plasmonic combinational logic circuits are explained using a finite element method with a COMSOL software package. The combinational circuits are created using insulator-metal-insulator technology with nanoscale plasmonic structures. In order to achieve an excellent transmission value, the phase angle of optical waves and the position of the control and input ports are the more crucial elements. In this design, the nanoscale combinational circuits are realized at a 35% transmission threshold to distinguish between the logic "0" and logic "1" stand on the interference between the input and control ports with 540n m×250n m dimensions and an 850nm resonant wavelength. The modulation depth, contrast ratio, and insertion loss have 97.38%, and 11.84 and 3.3dB for the HA, and they have 92.38%, and 7.12 and -1.41d B for the HS, respectively.

Geometric and non-geometric impact on Coanda effect propulsion device for UUV application

The present study investigated the effect of geometrical and non-geometrical parameters on the thrust performance of a pump-valve propulsion device consisting of a Coanda effect valve (CEV) and a pump. A more accurate theoretical model was also developed to predict the thrust of the pump-valve device. Firstly, a rough thrust model was developed based on existing theory to predict the thrust and energy loss generated by the pump-valve device under different exit and nozzle areas. Considering the limitations of the theoretical analysis, numerical simulations were carried out to evaluate the effect of various geometrical and non-geometrical parameters, including nozzle shape, nozzle area, control port width, exit area, inlet flow rate, etc., on the thrust performance of the CEV and the pump-valve device. Due to the margin between simulation thrusts and theoretical thrusts, we built an experimental platform and carried out relevant experiments. The experimental data verified the simulation results, and on this basis, the original thrust prediction model was corrected.

Nanoscale plasmonic logic gates design by using an elliptical resonator.

This study implemented AND, NAND, OR, XOR, NOR, XNOR, and NOT plasmonic logic gates using the finite element method. The all-optical nanoscale logic gates were designed using a single structure based on the technology of insulator-metal-insulator nanoscale plasmonic waveguides. The phase of optical waves and the position of the control and input ports are the most important factors for attaining the optimal transmission value based on interference between the input and control ports. The transmission threshold is 35%, and 850 nm is the operating wavelength. This design creates nanoscale logic gates with a structure dimension of 250nm×250nm. The transmission threshold, modulation depth, contrast ratio, and insertion loss criteria were proposed to evaluate the efficacy of the all-optical gates.

Prediction System for Overhead Cranes Based on Digital Twin Technology

To solve the problems of inaccurate quality inspection and poor safety maintenance of traditional overhead cranes, this study has developed a prediction system for overhead cranes based on digital twin technology. First, interworking of the data flow between the control port of the overhead crane and the digital twin system is realized. Then, finite element technology is exploited to calculate the stress of the crane bridge, thereby performing stress rendering of the digital twin system. Next, the life of bridge cranes is predicted by the stress and strain of their main girders. Finally, synchronous overhead-crane communication combines the virtual twin system and the actual control system of the crane. The study results provide a reference for developing crane software based on digital twins.

Performance evaluation of a time-division multiplexed fiber Bragg grating sensor based onheterodyne detection.

Using a technique to observe reflection spectra, the signal-to-noise ratio can be improved for time-division multiplexed interrogation of three fiber Bragg gratings (FBGs) based on heterodyne detection methods. To calculate peak reflection wavelengths of the FBG reflections, absorption lines of 12 C 2 H 2 are used as wavelength markers, and temperature dependence of the peak wavelength is measured for one FBG. Positioning the FBGs at a distance of 20km from the control port demonstrates the applicability of this method to a long sensor network.

Some effects of detection dogs on passenger behavior at border control ports.

Detection dogs are used at border controls as an antecedent intervention to deter the smuggling of contraband. However, there is little research that has explored how the presence of dogs might affect passenger behavior. We observed passengers' behavior at a port when there was an officer alone, an officer with a dog, and an officer with a dog wearing a florescent yellow jacket with "police" written on it for increased salience. We measured eye contact, vocal-verbal interactions, facial expressions, and nonvocal verbal gestures toward the officer and dog, and changes in passenger direction. Passengers looked, talked, and had the highest frequencies of positive facial expressions when the dog was not wearing a jacket. However, passengers looked toward the dog the quickest and had the highest frequency of negative facial expressions and gestures when the dog was wearing a jacket. We discuss how these findings might inform antecedent interventions to address undesirable behavior such as smuggling.

Multiple-input hybrid plasmonic OR logic gate with a nanostructure.

A multiple-input hybrid plasmonic OR logic gate has been constructed, analyzed, and simulated utilizing the finite element method by using the COMSOL software package version 5.5. To realize the suggested three- and four-input hybrid plasmonic OR gate, constructive and destructive interference has been standard among the input ports and control port. The factors used to evaluate the functionality of the nanoscale gate are the contrast ratio, modulation depth (MD), and insertion losses (ILs). In contrast, the optical power ratio at the output port, known as the transmission value (T value), has been measured and used to distinguish between logic 1 (ON-state) and logic 0 (OFF-state). The transmission threshold value in this article was 25%, and the wavelength range considered to display the result was from 1000 to 2000nm. The three-input hybrid OR gate occupied a size of 500n m×400n m with transmission amplification results from the best T value of 216.5 % with 98.85% as a MD. In comparison, the four-input OR gate comes with a size of 600n m×400n m at the best T value of 301.5%, supported by a 99.33% as the MD. The IL values for the three-input and four-input designs are -4.07 and -5.4d B, respectively. The system resonance wavelength is 1310nm.

Broadband acoustic triggers based on multiport waveguide structures

The study of acoustic information processing has attracted great attention owing to its advantages of anti-electromagnetic interference and low energy consumption. Acoustic logic device, as a fundamental component, plays an important role in designing integrated acoustic systems. In the past few years, with the rapid development of sonic crystals, acoustic metamaterials and metasurfaces, researchers have demonstrated a variety of acoustic logic gates based on different mechanisms, and have devoted their efforts to the promotion of the practical applications. The more complex acoustic triggers with broad bandwidth and subwavelength size are very important for developing integrated sound devices, but it is difficult to realize them. In this work, we design two types of acoustic triggers based on the mechanisms of linear interference and phase modulation. The acoustic trigger with a width of 0.32<i>λ</i> and length of 0.82<i>λ</i> is composed of phased unit cells and multi-port waveguide structures, showing a subwavelength structure. Based on the phase modulation of the phased unit cells and the mechanism of linear interferences, the acoustic T-type trigger and D-type trigger with the same threshold are designed and demonstrated experimentally. The corresponding working bands of the T-type and D-type triggers are 3.293–4.069 kHz and 3.400–4.138 kHz, and their fractional bandwidths (the ratio of the bandwidth to the center frequency) can reach about 0.23 and 0.22, respectively, showing a broadband characteristic of both triggers. The mechanism of the T-type trigger is attributed to the linear interference caused by two phased unit cells with a phase difference of π. However, the realization of the D-type trigger is closely related to the incident sound energy and the phase modulation caused by the phased unit cell in the control port. The measured results and simulated results agree well with each other. Compared with other types of acoustic logic devices, the designed acoustic triggers have the advantages of broad bandwidth, subwavelength size, same threshold, and passive structure, as well as being easy to integrate, thus providing great potential applications in acoustic computing, acoustic communication, acoustic information processing and integrated acoustics. Our experimental demonstration of acoustic triggers can further promote the theoretical and experimental investigations of basic acoustic components.