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Non-singular fast terminal sliding mode control of robotic manipulator with prescribed performance

Journal of engineering and Applied Science 2024年第1期71卷 217页

作者： Zhang, Xin Wang, Ruikang School of Automation and Electrical Engineering of Lanzhou Jiaotong University Lanzhou Jiaotong University Lanzhou China

Considering the improvement of transient response when tracking the trajectory of the robotic manipulator, a novel prescribed performance non-singular fast terminal sliding mode (PPNFTSM) controller is designed. The method performs the controller design by introducing performance functions with constraint effects, and, at the same time, transforms the trajectory tracking deviation using the hyperbolic tangent function, and a new error performance index function is designed accordingly to solve the dilemma that the prescribed performance control (PPC) depends on the first constrained value of the system;the error obtained from the transformation is then combined with the non-singular fast terminal sliding mode (NFTSM) for controller design. The proof of the stability is established based on Lyapunov functions. The proposed method does not require an initial tracking condition. This is verified by simulation and ensures that the tracking deviation approaches a delimited region near the equilibrium point with a prescribed transient performance and strong robust performance. © The Author(s) 2024.

关键词： Hyperbolic functions

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FDNet:Fourier transform guided dual-channel underwater image enhancement diffusion network

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Science China(Technological Sciences) 2025年第1期68卷 58-74页

作者： Zhen ZHU Xiaobo LI Qianwen MA Jingsheng ZHAI Haofeng HU School of Marine Science and Technology Tianjin UniversityTianjin 300072China College of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China

Due to the scattering and absorption of light,underwater imaging yields suboptimal results characterized by low brightness,diminished image contrast,and the loss of *** learning-based underwater image enhancement(UIE)methods mainly focus on addressing these issues in the spatial domain,with limited attention to the Fourier frequency *** propose the Fourier transform guided dual-channel underwater image enhancement diffusion network(FDNet),aiming to fully leverage frequency domain information and the characteristics of a diffusion-based generation *** amplitude-phase dualchannel not only effectively provides feedback on the energy distribution of the image but also incorporates crucial image structure and texture *** on these advantages,we first introduce a Fourier transform-based amplitude-phase dualchannel enhancement front-end network for *** network significantly improves the quality of the network's image input,including brightness and contrast,by incorporating phase congruency edge enhancement and prior-driven amplitude mapping *** preceding network mitigates the overall training challenges caused by poor input image ***,the application of denoising networks based on lightweight transformers effectively improves the computational time required for each iteration during model *** results indicate that FDNet outperforms many current learning-based UIE algorithms in restoring images across multiple real underwater image datasets,demonstrating more robust generalization capabilities in degraded underwater *** competitive performance advantage achieved in enhancing visual quality underscores the effectiveness of our method.

关键词： underwater image enhancement Fourier transform deep neural network phase congruency diffusion model

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New technology for pipeline defect detection

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Science China(Technological Sciences) 2024年第4期67卷 1294-1296页

作者： NIU YanXia SUN LongXiang WANG YiXuan SHEN GuoLang SHI Yan Engineering Training Center Beihang UniversityBeijing 102206China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Mechanical and Electronic Engineering Jingdezhen Ceramic UniversityJingdezhen 333403China

Rupture and leakage of urban sewer pipes will seriously affect the daily life of urban *** detection is one of the most important segments in the assessment of pipeline health *** the continuous extension of pipeline ... 详细信息

关键词： corrosion defect pipeline

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A Novel Direct Instantaneous Torque Control Strategy of Permanent Magnet-Assisted Switched Reluctance Motor with Zero Voltage Modulation

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Progress In Electromagnetics Research C 2024年 148卷 71-82页

作者： Huang, Chaozhi Xiao, Renquan Gong, Chengyi Xiao, Yong School of Electrical Engineering and Automation Jiangxi University of Science and Technology Jiangxi Ganzhou341000 China

To reduce large torque ripple in permanent magnet-assisted switched reluctance motors (PMa-SRMs), a novel direct instantaneous torque control (DITC) strategy with zero-voltage modulation is proposed in this paper, where a fixed-frequency pulse width modulation (PWM) is replaced by the conventional DITC hysteresis controller to optimize zero-voltage insertion time through zero-voltage decentralized modulation to minimize switching losses. Control intervals are then divided based on inductance and torque-to-current ratio (TCR) characteristics, with adaptive duty cycle adjustments to enhance torque tracking and reduce ripple. Additionally, the optimal turn-on and turn-off angles are determined by the dung-beetle-optimized back propagation (BP) neural network (DBO-BP) algorithm, which suppresses the torque ripple, lowers phase current peaks, and improves motor efficiency. The feasibility and effectiveness of the proposed method are validated by simulations and experiments with a three-phase 6/20 PMa-SRM. © 2024, Electromagnetics Academy. All rights reserved.

关键词： Permanent magnets

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Study on plasma expansion model of primary discharge on spacecraft solar array

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Plasma Science and Technology 2024年第11期26卷 87-95页

作者： Dejie WEI Jianwen WU Liying ZHU School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191People’s Republic of China Institute of Spacecraft System Engineering CAST Beijing 100094People’s Republic of China

In the space plasma environment, primary discharge may occur on the solar array and evolve into a destructive sustained arc, which threatens the safe operation of the spacecraft. Based on the plasma expansion fluid theory, a new multicomponent plasma expansion model is proposed in this study, which takes into account the effects of ion species, ion number, initial discharge current, and Low Earth Orbit(LEO) plasma environment. The expansion simulation of single-component and multicomponent ions is carried out respectively, and the variations of plasma number density, expansion distance, and speed during the expansion process are *** with the experimental results, the evolution of propagation distance and speed is closed and the error is within a reasonable range, which verifies the validity and rationality of the model. The propagation characteristics of the primary discharge on the solar array surface and the influence of the initial value on the maximum propagation distance and the propagation current peaks are investigated. This study can provide important theoretical support for the propagation and evolution of the primary discharge and the key behavior of the transition to secondary discharge on spacecraft solar array.

关键词： primary discharge plasma expansion propagation characteristics spacecraft solar array

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On-ramp mixed traffic flow merging model with connected and autonomous vehicles

Advances in Transportation Studies

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Advances in Transportation Studies 2024年 63卷 159-176页

作者： Kuang, X.Y. Xiao, H.B. Huan, X.L. School of Electrical Engineering and Automation Jiangxi University of Science and Technology Jiangxi Ganzhou341000 China

The impacts of merging on mixed traffic flow in the highway on-ramp zone are numerically investigated in this paper. An on-ramp mixed traffic flow merging model is proposed. Our model focuses on the on-ramp merging zone and considers a mixed traffic flow comprising of connected and automated vehicles (CAVs) and human-driven vehicles (HDVs). Firstly, we establish the Velocity-Modified Comfortable Driving (V-MCD) model for HDVs, which incorporates a velocity estimation module into the base Modified Comfortable Driving (MCD) model. The Cooperative Adaptive Cruise Control (CACC) model developed by PATH Labs is used for CAVs. A cooperative merging model has been developed to capture the interaction behavior of vehicles in various driving scenarios. Merging rules are established based on vehicle type and merging order. The merging rules for HDV-HDV are based on safety gap. Meanwhile, those for CAV-HDV are based on velocity difference, and for CAV-CAV are based on first-come-first-served. We conduct numerical simulation experiments to derive the fundamental diagram of the mixed flow and analyze the interaction between vehicles on the on-ramp and mainline. The simulation results indicate that the V-MCD model can effectively reflect on the hysteresis effect caused by on-ramp merging vehicles in real traffic scenarios. The increase in CAV penetration improves road traffic efficiency in terms of both traffic velocity and capacity. However, as the penetration of CAVs continues to rise, their positive impact will diminish. The sensitivity analysis of the hysteresis effect at both micro and macro levels can enhance our understanding of the impacts on traffic flow. As the hysteresis effect increases, merging has a greater impact on mainline upstream traffic, leading to reduce headway and more erratic velocity changes. © 2024, Aracne Editrice. All rights reserved.

关键词： Sensitivity analysis

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Simulation and analysis of soil homogenization drills based on discrete element method and response surface methodology

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Particuology 2024年第5期88卷 128-148页

作者： Zhipeng Wang Tong Zhu Youzhao Wang Song Yang Feng Ma Xu Li Institute of Process Equipment and Environmental Engineering School of Mechanical Engineering and AutomationNortheastern UniversityShenyang110819China Liaoning Coning Testing Co. Ltd.Shenyang110170 China

Currently,rotary drilling is one of the main pieces of equipment used for in-situ remediation of contaminated ***,this equipment has problems such as uneven mixing and low utilization efficiency,which affect the efficiency of in-situ soil *** improve the efficiency of in-situ soil remediation,this paper takes contaminated black soil as the research object,and the structural design of the new three-stage soil remediation auger is carried out based on *** mixing process of soil and heavy metal passivator under different motion and structural parameters was investigated by the discrete element method(DEM)and response surface *** experimental design was based on rotational speed,homogenizing mixing time,crushing section pitch,and homogenizing section pitch as factors,and soil fragmentation ratio,the coefficient of dispersion,and torque as optimization *** kinematic and structural parameters of the three-stage auger drill bit were then optimized using the one-factor method,the orthogonal test,and the response surface methodology,*** test method uses a one-way test to determine the central level value of the orthogonal test and a comprehensive balance method to determine the best combination of parameters for the orthogonal test,which is then used as the central value of the response surface test for parameter *** optimal combinations of kinematic and structural parameters of the three-stage auger drill bit are determined and validated using response surface *** optimum combination of parameters was found to be a speed of 129 rpm,a homogenizing mixing time of 24 s,a pitch of 165 mm in the crushing section,and a pitch of 132 mm in the homogenizing *** error between the optimal value of the predicted model using the response surface method and the actual simulated value under the optimal parameters is 4.2%,4.9%,and 5.3%,*** optimized factor parameters provide a refe

关键词： Black soil Mixing homogeneity Orthogonal method Response surface methodology Discrete element method Soil remediation

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Evaluating transient behaviour of large-scale photovoltaic systems during lightning events using enhanced finite difference time domain method with variable cell size approach

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High Voltage 2024年第3期9卷 636-647页

作者： Ibrahim Hetita Diaa-Eldin A.Mansour Yang Han Ping Yang Congling Wang Mohamed M.F.Darwish Matti Lehtonen Amr S.Zalhaf School of Mechanical and Electrical Engineering University of Electronic Science and Technology of China(UESTC)ChengduChina Electrical Power and Machines Engineering Department Faculty of EngineeringHelwan UniversityCairoEgypt Electrical Power and Machines Engineering Department Faculty of EngineeringTanta UniversityTantaEgypt Department of Electrical Power Engineering Faculty of EngineeringEgypt-Japan University of Science and TechnologyAlexandriaEgypt Department of Electrical Engineering Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of Electrical Engineering and Automation School of Electrical EngineeringAalto UniversityEspooFinland

Photovoltaic(PV)arrays are usually installed in open areas;hence,they are vulnerable to lightning strikes that can result in cell degradation,complete damage,service disruption,and increased maintenance *** a result,it is imperative to develop an effective and efficient lightning protection system by evaluating the transient behaviour of PV arrays during lightning *** aim is to evaluate the transient analysis of large-scale PV systems when subjected to lightning strikes using the finite difference time domain(FDTD)*** overvoltages are calculated at various points within the mounting *** optimise the FDTD method's execution time and make it more suitable for less powerful hardware,a variable cell size approach is ***,larger cell dimensions are used in the earthing system and smaller cell dimensions are used in the mounting *** FDTD method is utilised to calculate the temporal variation of transient overvoltages for large-scale PV systems under different scenarios,including variations in the striking point,soil resistivity,and the presence of a metal *** results indicate that the highest transient overvoltages occur at the striking point,and these values increase with the presence of a PV metal frame as well as with higher soil ***,a comparison is performed between the overvoltage results obtained from the FDTD approach and the partial element equivalent circuit(PEEC)method at the four corner points of the mounting systems to demonstrate the superior accuracy of the FDTD ***,a laboratory experiment is conducted on a small-scale PV system to validate the simulation *** calculated overvoltages obtained from the FDTD and PEEC methods are compared with the measured values,yielding a mean absolute error of 5%and 11%for the FDTD and PEEC methods,respectively,thereby confirming the accuracy of the FDTD simulation model.

关键词： transient behaviour finite

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Lightweight Rice Planthopper Identification Method Based on YOLOv5

IAENG International Journal of Computer Science

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IAENG International Journal of Computer Science 2024年第8期51卷 1079-1085页

作者： Li, Siquan Wang, Yi Shi, Teng Chen, Xi Tang, Zhen Zeng, Ziyu Wen, Xin Shang, Yanling School of Automation Nanjing Institute of Technology Nanjing211167 China School of Mechanical Engineering Nanjing Institute of Technology Nanjing211167 China School of Automation Nanjing Institute of Technology Nanjing211167 China School of Computer engineering Nanjing Institute of Technology Nanjing211167 China School of Automation Nanjing Institute of Technology Nanjing211167 China

The identification and classification of pests in rice field are the prerequisites of early warning systems for pest disasters. Among these pests, the rice planthoppers cause the most serious damage. However, the existing deep learning models for rice planthopper recognition are characterized by large size and numerous parameters, which makes them unsuitable for the deployment on embedded devices with limited computational resources. To address this issue, a lightweight rice planthopper recognition model based on YOLOv5 is proposed in this paper. In the model, a lightweight convolutional network named GhostNet is employed as the backbone to reduce the operational parameters. Additionally, a convolutional attention module (CBAM) is integrated into the backbone network to effectively enhance the transmission of deep information, so as to improve the model’s ability of recognizing rice planthopper images. The original CIoU loss function is replaced by the SIoU loss function to expedite model convergence. Experimental results demonstrate that the modified model achieves the mAP@0.5 as 82.8%, with the parameter count of 3.12×106 and the model size of 7.2MB. Compared to the original model, it is a reduction of 46.7% in size and 43.3% in parameters, with a minor accuracy loss of 0.1%. Clearly, the improved model can achieve lightweight characteristics and robust performance, and thus it provides a theoretical and practical foundation for early warning systems against rice planthopper infestations in rice fields. © (2024), (International Association of Engineers). All Rights Reserved.

关键词： Convolution

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Investigation of Stator/Rotor Pole Number Combinations and PM Numbers on Variable Flux Leakage PM Machine

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Progress In Electromagnetics Research C 2024年 148卷 61-70页

作者： Liu, Xiping Lu, Ruipan Liu, Yuxin Wang, Wenrui School of Electrical Engineering and Automation Jiangxi University of Science and Technology Jiangxi Ganzhou341000 China

This paper proposes a variable flux leakage permanent magnet (PM) machine and investigates the impact of slot and pole number combinations on the electromagnetic performance of a variable flux leakage permanent magnet machine (VFL-PMM). The stator armature winding dq-axis magnetic circuit is designed to couple with the PM leakage magnetic circuit by the deliberate establishment of a leakage-guided magnetic barrier and a poly-magnetic barrier on the rotor side. The VFL-PMM with 12s10p-DL (double layers) fractional slot centralized winding (FSCW) serves as an illustrative example of global parametric modelling of the machine. The objective is to optimize the split ratio, average torque, torque ripple, and PM utilization of the machine to obtain the optimum amount of the machine. The relationship between the no-load, on-load characteristics, and variable flux leakage characteristics of 12s8p, 12s10p, 12s14p with double-layer FSCW and 12s10p with single-layer FSCW are studied comparatively. The machines are analyzed and optimized using 2D finite element analysis. © 2024, Electromagnetics Academy. All rights reserved.

关键词： Stators

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