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An experimental study on photovoltaic module with optimum power point tracking method

INTERNATIONAL TRANSACTIONS ON ELECTRICAL ENERGY SYSTEMS 2020年第1期30卷

作者： Thangamani, Kaliraja Manickam, Martin Leo Chellaiah, Chellaswamy SV Engn Coll Women Dept ECE Tirupati Andrapradesh India St Joseph Coll Engn Dept ECE Chennai Tamil Nadu India Lords Inst Engn & Technol Dept ECE Hyderabad India Sathyabama Inst Sci & Technol Dept Elect Chennai Tamil Nadu India

With the latest development in the area of power electronics, the photovoltaic (PV) cell can be made to operate at the optimum peak point with increased system efficiency. To maximize the power on photovoltaic cells under various conditions, optimum power point tracking (OPPT) methods such as conventional and soft computing methods are used. But it is not providing accurate and efficient output due to its randomness, fixed step size, and poor convergence. In this paper, the adaptive differential evolution (ADE) algorithm is introduced in the solar module to obtain the maximum power, and it has the ability to reach the optimum peak with the shorter time period. An Apriori method is used in the proposed ADE algorithm, wherein mutation factor and crossover are used as control parameters to increase the speed. The ruggedness of the ADE algorithm is tested under different shading condition such as no shading, 30% shading, and 50% shading condition. Extensive simulation has been carried out using PV solar module, and the analysis has been tabulated and compared with the existing results. Various statistical metrics such as root mean square error, the relative error, tracking efficiency, standard deviation, and efficiency are used to evaluate the effectiveness and validate the feasibility of the proposed method. Further, hardware has been implemented and tested with this algorithm.

关键词： differential evolution algorithm optimum power point tracking photovoltaic cell shading condition

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An optimization approach to design deformation patterns in perforated mechanical metamaterials using distributions of Poisson's ratio-based unit cells

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COMPOSITE STRUCTURES 2022年 281卷

作者： Yao, Jianfei Su, Yongfei Scarpa, Fabrizio Li, Yan Beijing Univ Chem Technol Coll Mech & Elect Engn Beijing 100029 Peoples R China Beijing Univ Chem Technol Beijing Key Lab Hlth Monitoring & Self Recovering Beijing 100029 Peoples R China Univ Bristol Bristol Composites Inst Bristol BS8 1TR Avon England Univ Bristol Dynam & Control Res Grp DCRG Bristol BS8 1TR Avon England

Two-dimensional metamaterials with patterns of perforations producing auxetic effects can exhibit variable and tailorable deformation mechanisms by varying the distributions of cells with different geometry parameters. The local homogenized Poisson's ratio can be used as a way to establish as a link between local unit cell parameters and global deformations. We propose here a Poisson's ratio-based unit cell distribution optimization method to design deformation patterns in a perforated structure. A plate-like structure with centresymmetric perforations is here divided into different regions with dissimilar unit cell topologies that possess different homogenized Poisson's ratio values. All the unit cells belonging to the same region have equal geometry. A differential evolution (DE) algorithm is used to optimize the permutation and combination of the homogenized local Poisson's ratios of the unit cells regions. A two-dimensional perforated structure that satisfies the required deformation pattern can be obtained by using the proposed method. Simulations and experiments show that the proposed approach can provide controllable shape changes of 2D perforated mechanical metamaterials under uniaxial tensile loading.

关键词： Mechanical metamaterials Perforations Designable deformation differential evolution algorithm Controllable shape

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Dimensional synthesis for a Rec4 parallel mechanism with maximum transmission workspace

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MECHANISM AND MACHINE THEORY 2020年 153卷 104008-104008页

作者： Che, Linxian Chen, Guowang Jiang, Haiyi Du, Li Wen, Shikun Chongqing Vocat Inst Engn Sch Intelligence Mfg & Traff 1 Nanbei Ave Chongqing 402260 Peoples R China Chongqing Technol & Business Univ Chongqing Municipal Key Lab Mech Design & Control Chongqing 400067 Peoples R China Chongqing Univ Technol Sch Mech Engn Chongqing 400054 Peoples R China

A 4-RUPaR parallel mechanism (named as Rec4) with Schoenflies motion has been taken as the research object, and its dimensional synthesis problem has been solved by intelligence algorithms. Using screw theory as a mathematical tool, this paper establishes two indices (i.e., the input transmission index and the output transmission index) to evaluate motion and force transmission performance of mechanism, and presents the definition and numerical calculation method of effective transmission positional workspace (ETPW). A constrained optimization model is constructed to formulate the design problem of dimensional parameters on the maximizing volume of ETPW, and differential evolution (DE) algorithm is employed to solve this problem. A real case of dimensional optimization design is given, and the results show that the proposed model and algorithm are feasible and effective. Furthermore, a comparative test on global optimization capability to solve the dimensional design case is carried out with genetic algorithm (GA), particle swarm optimization (PSO), and DE algorithm, and the numerical experiments demonstrate that DE outperforms GA and PSO in terms of performance indices. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Parallel mechanism Transmission performance index Effective transmission workspace Dimensional optimization design differential evolution algorithm

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Detection of Abnormal Human Behavior in Video Images based on a Hybrid Approach

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INTERNATIONAL JOURNAL OF ADVANCED COMPUTER SCIENCE AND APPLICATIONS 2022年第11期13卷 346-356页

作者： Bai Ya-meng Wang Yang Wu Shen-shen Jiaozuo Univ Sch Informat Engn Jiaozuo 412000 Henan Peoples R China

The analysis of human movement has attracted the attention of many scholars of various disciplines today. The purpose of such systems is to perceive human behavior from a sequence of video images. They monitor the population to find common properties among pedestrians on the scene. In video surveillance, the main purpose of detecting specific or malicious events is to help security personnel. Different methods have been used to detect human behavior from images. This paper has used an efficient computational algorithm for detecting anomalies in video images based on the combined approach of the differential evolution algorithm and cellular neural network. In this method, the input image's gray-level image is first generated. Because it may be possible to identify several large areas in the image after the threshold, the largest white area is selected as the target area. The images are then used to remove noise, smooth the image, and fade the morphology. The results showed that the proposed method has higher speed and accuracy than other methods. The advantage of the algorithm is that it has a runtime of three seconds on a home computer, and the average sensitivity criterion is 98.6% (97.2%).

关键词： Cellular neural network detection of abnormalities differential evolution algorithm video images

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Study on the Modeling and Compensation Method of Pose Error Analysis for the Fracture Reduction Robot

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MICROMACHINES 2022年第8期13卷 1186-1186页

作者： Liu, Minghe Li, Jian Sun, Hao Guo, Xin Xuan, Bokai Ma, Lifang Xu, Yuexuan Ma, Tianyi Ding, Qingsong An, Baichuan Hebei Univ Technol Sch Artificial Intelligence & Data Sci & Engn Res Minist Educ Tianjin 300130 Peoples R China Beijing Univ Posts & Telecommun Sch Automat Beijing 100876 Peoples R China Natl Res Ctr Rehabil Tech Aids Beijing Key Lab Rehabil Tech Aids Old Age Disabil Beijing 100176 Peoples R China Natl Res Ctr Rehabil Tech Aids Key Lab Neurofunct Informat & Rehabil Engn Minist Civil Affairs Beijing 100176 Peoples R China

Background: In the process of fracture reduction, there are some errors between the actual trajectory and the ideal trajectory due to mechanism errors, which would affect the smooth operation of fracture reduction. To this end, based on self-developed parallel mechanism fracture reduction robot (FRR), a novel method to reduce the pose errors of FRR is proposed. Methods: Firstly, this paper analyzed the pose errors, and built the model of the robot pose errors. Secondly, mechanism errors of FRR were converted into drive bar parameter's errors, and the influence of each drive bar parameter on the robot pose error were analyzed. Thirdly, combining with Cauchy opposition-based learning and differential evolution algorithm (DE), an improved whale optimization algorithm (CRLWOA-DE) is proposed to compensate the end-effector's pose errors, which could improve the speed and accuracy of fracture reduction, respectively. Results: The iterative accuracy of CRLWOA-DE is improved by 50.74%, and the optimization speed is improved by 22.62% compared with the whale optimization algorithm (WOA). Meanwhile, compared with particle swarm optimization (PSO) and ant colony optimization (ACO), CRLWOA-DE is proved to be more accurate. Furthermore, SimMechanics in the software of MATLAB was used to reconstruct the fracture reduction robot, and it was verified that the actual motion trajectory of the CRLWOA-DE optimized kinematic stage showed a significant reduction in error in both the x-axis and z-axis directions compared to the desired motion trajectory. Conclusions: This study revealed that the error compensation in FRR reset process had been realized, and the CRLWOA-DE method could be used for reducing the pose error of the fracture reduction robot, which has some significance for the bone fracture and deformity correction.

关键词： fracture reduction robot error model whale optimization algorithm differential evolution algorithm opposition-based learning error compensation

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Handwritten Recognition Based on Extreme Learning Machine Optimized by Difference evolutionary algorithm

World Scientific Research Journal

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World Scientific Research Journal 2021年第1期7卷 302-312页

作者： Yuhang Zhang Yuan Chang Chenwen Dong Zai Cai

With the development of science and technology, the phenomenon of paperless has gradually become common in daily life, and people's requirements for the accuracy of handwritten font recognition have gradually increased. MNIST is the most basic and important data set for studying handwritten font recognition. In this paper, a finite difference evolutionary algorithm is proposed to optimize the extreme learning machine (ELM) model, which referred as DE-ELM hereafter. The DE-ELM model is applied to handwritten numeral recognition. Extreme learning machine is one of the single hidden layer feedforward neural (SLFN) network, its superior performance as the neural network and the rise of artificial intelligence, compared with other traditional neural network such as deep learning, extreme learning machine has higher precision and shorter training time. However, since in the extreme learning machine, the number of hidden nodes is allocated a priori, the hidden node parameters are randomly selected in the initial stage of the model and remain unchanged during the training process, so there may be many non-optimal nodes in the model, and the minimization function contributes less. differential evolution algorithm is a simple but powerful group-based random direct search technology. This article uses differential evolution algorithm to select the hidden node parameters in the extreme learning machine model to make the extreme learning machine achieve better results. The optimized model is classified on the handwritten data set MNIST, and compared with other neural network classification effects, the accuracy of DE-ELM model classification has been improved.

关键词： differential evolution algorithm Estimate learning machine Handwritten recognition

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Identification of the critical depth-of-cut through a 2D image of the cutting region resulting from taper cutting of brittle materials

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MEASUREMENT SCIENCE AND TECHNOLOGY 2018年第5期29卷 055003-055003页

作者： Gu, Wen Zhu, Zhiwei Zhu, Wu-Le Lu, Leyao To, Suet Xiao, Gaobo Nanjing Univ Sci & Technol Sch Mech Engn Nanjing 210094 Jiangsu Peoples R China Hong Kong Polytech Univ Dept Ind & Syst Engn State Key Lab Ultra Precis Machining Technol Kowloon Hong Kong Peoples R China Kyoto Univ Dept Microengn Nishikyo Ku Kyoto 6158540 Japan

An automatic identification method for obtaining the critical depth-of-cut (DoC) of brittle materials with nanometric accuracy and sub-nanometric uncertainty is proposed in this paper. With this method, a two-dimensional (2D) microscopic image of the taper cutting region is captured and further processed by image analysis to extract the margin of generated micro-cracks in the imaging plane. Meanwhile, an analytical model is formulated to describe the theoretical curve of the projected cutting points on the imaging plane with respect to a specified DoC during the whole cutting process. By adopting differential evolution algorithm-based minimization, the critical DoC can be identified by minimizing the deviation between the extracted margin and the theoretical curve. The proposed method is demonstrated through both numerical simulation and experimental analysis. Compared with conventional 2D- and 3D-microscopic-image-based methods, determination of the critical DoC in this study uses the envelope profile rather than the onset point of the generated cracks, providing a more objective approach with smaller uncertainty.

关键词： diamond cutting brittle material critical depth-of-cut differential evolution algorithm

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Design and analysis of a novel piezoelectrically actuated vibration assisted rotation cutting system

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SMART MATERIALS AND STRUCTURES 2018年第9期27卷 095020-095020页

作者： Lu, Mingming Zhao, Dongpo Lin, Jieqiong Zhou, Xiaoqin Zhou, Jiakang Chen, Bin Wang, Hao Changchun Univ Technol Sch Mechatron Engn Key Lab Micronano & Ultraprecis Mfg Jilin Prov Changchun 130012 Jilin Peoples R China Jilin Univ Sch Mech Sci & Engn Changchun 130022 Jilin Peoples R China

Elliptical vibration cutting (EVC) technology has been paid much attention as the unique characteristics of the intermittent cutting and friction reversal, but the residual-height between adjacent trajectories can not be eliminated. In order to solve the problem, we developed a new vibration assisted rotation cutting (VARC) system in this paper. The system has the characteristics of the pseudo-intermittent cutting and friction reversal, which greatly extends the tool-life, reduces cutting forces, and improves the accuracy of the work-piece. The mechanical system based on the parallel kinematic configuration of the two-axis, where the positioning of the tool position has ensured by the rotary motion platform (RMP). The L-shaped flexure hinges are used as the guidance flexure mechanism, to rotate of the RMP. Flexures hinge structure and piezoelectrically actuated are employed positioning in the design. The kinematic analysis of the pseudo-rigid-body model, the matrix-based compliance modeling method is applied for the compliance modeling, and the dynamics characteristic is modeled by using the Lagrangian principle of VARC system. The structural parameters are optimized by the improved differential evolution algorithm, and the theoretical modeling is validated by finite element analysis. Off-machine performance examinations were conducted to evaluate the parasitic motions, resolution, hysteresis, stroke, and frequency of the developed system. The results showed that the motion stroke of the piezoelectric actuator input end could reach up to 26.34 mu m with a resolution of 8 nm, moreover, the coupling ration could be effectively decreased within 0.64%. The superior performances and easily achievable structure well facilitate practical applications of the proposed system in micro/nano-machining.

关键词： vibration assisted rotation cutting pseudo-rigid-body model compliant manufacturing systems Lagrangian principle differential evolution algorithm

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Simulation and Experiment of Active Vibration Control Based on Flexible Piezoelectric MFC Composed of PZT and PI Layer

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POLYMERS 2023年第8期15卷 1819-1819页

作者： Li, Chong Shen, Liang Shao, Jiang Fang, Jiwen Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212100 Peoples R China

In order to improve the vibration suppression effect of the flexible beam system, active control based on soft piezoelectric macro-fiber composites (MFCs) consisting of polyimide (PI) sheet and lead zirconate titanate (PZT) is used to reduce the vibration. The vibration control system is composed of a flexible beam, a sensing piezoelectric MFC plate, and an actuated piezoelectric MFC plate. The dynamic coupling model of the flexible beam system is established according to the theory of structural mechanics and the piezoelectric stress equation. A linear quadratic optimal controller (LQR) is designed based on the optimal control theory. An optimization method, designed based on a differential evolution algorithm, is utilized for the selection of weighted matrix Q. Additionally, according to theoretical research, an experimental platform is built, and vibration active control experiments are carried out on piezoelectric flexible beams under conditions of instantaneous disturbance and continuous disturbance. The results show that the vibration of flexible beams is effectively suppressed under different disturbances. The amplitudes of the piezoelectric flexible beams are reduced by 94.4% and 65.4% under the conditions of instantaneous and continuous disturbances with LQR control.

关键词： piezoelectric polymer flexible beam LQR differential evolution algorithm vibration control

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OPTIMUM DESIGN OF FIBER ANGLE AND HOLE ORIENTATION OF AN ORTHOTROPIC PLATE

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JOURNAL OF THEORETICAL AND APPLIED MECHANICS 2018年第1期56卷 297-311页

作者： Zhang, Xiaoli Lu, Aizhong Wang, Shaojie Zhang, Ning North China Elect Power Univ Inst Hydroelect & Geotech Engn Beijing Peoples R China

With the goal of decreasing the stress concentration along the hole boundary in an orthotropic plate under inequi-biaxial loadings, an optimum design of the fiber angle and hole orientation is presented. The maximum absolute tangential stress along the hole boundary is taken as the objective function, and the fiber orientation angle and the hole orientation angle are considered as design variables. The conformal transformation method of a complex function and the differential evolution (DE) algorithm are used. Two non-circular shapes, ellipse and hexagon are taken as examples to analyze the problem. Based on the results, we can conclude that the major axis of elliptical holes should be designed in the direction of the maximum external loading for a perforated structure in an orthotropic plate. However, the principal direction that has the larger Young's modulus should be inclined to the direction of the minimum loading, especially for a significantly orthotropic plate.

关键词： orthotropic plate fiber orientation angle hole orientation angle conformal transformation method differential evolution algorithm

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