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A Review on Modeling of Bionic Flow Control Methods for Large-Scale Wind Turbine Blades

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Journal of Thermal Science 2021年第3期30卷 743-757页

作者： zhang Mingming zhang yi’nan CAI Chang CAO Huijing zhang Ziliang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China Key Laboratory of Wind Energy Utilization Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory For Clean energy Chinese Academy of SciencesDalian 116023China Institute of Science and Technology China Three Gorges CorporationBeijing 100038China

Due to complicated working conditions,the normal operating large-scale wind turbine blades are often suffering from some inevitable problems,i.e.,friction adhesion,flow separation and acoustic noise,which may significantly affect the aerodynamic performance of the blades and thus the wind turbine ***,effective measurements must be taken to solve these ***,several novel bionic flow control methods by mimicking shark skin,whale fin and owl wing,i.e.,riblet,leading-edge protuberance and trailing-edge serration,have been recently studied,and good progresses have been made in terms of effectiveness,analysis and ***,these potential techniques are unable to be widely applied within wind energy community due to the lack of reasonable modeling methods,clearly reflecting the effect of bionic structures on the flow field around,which results in incapability to carry out further optimal design of bionic *** this end,this review paper first concentrated on a summary of the control mechanisms of three bionic *** on this,some feasible ideas of model buildup were ***,the flow analyses around the typical blade airfoils were chosen as case studies to verify the feasibility and accuracy of these simulation methods.

关键词： riblets leading-edge protuberances trailing-edge serrations modeling method

Optimal Combinations and Variable Departure Intervals for Micro Bus System

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Tsinghua Science and Technology 2017年第3期22卷 282-292页

作者： Jiaoyang Li Jianming Hu yi zhang Department of Automation Tsinghua UniversityBeijing 100084China

It is becoming increasingly difficult for Chinese citizens to access traditional public transport because of overcrowded community structures. Therefore, novel ideas are required to improve the transport system. In this respect, this study considers the design of a public transport scheduling model for a micro system. The model aims to minimize passenger waiting time and maximize number of passengers one bus carries, by simultaneously optimizing departure intervals and use of traditional and rapid buses. The model is superior to traditional models, as it analyzes the phenomena of vehicle overtaking, vehicle capacity limit, and passenger determination uncertainty. In addition, the model is a sophisticated nonlinear multi-objective optimization problem and contains more than one type of decision variable, therefore two composite algorithms, HPSO and GAPSO, are proposed, which are improvements of the Genetic Algorithm （GA） and Particle Swarm Optimization （PSO）. These two algorithms are compared to the classical GA with respect to stability and effect, and the results show them to be strong in both respects. In addition, the simultaneous optimization method has evident advantages compared to single-method optimizations.

关键词： bus scheduling optimization model rapid bus Particle Swarm Optimization (PSO) Genetic Algorithm(GA)

Robust dissipative control for time-delay stochastic jump systems

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Journal of Systems Engineering and Electronics 2011年第2期22卷 314-321页

作者： Lijuan Xu Tianping zhang Yang yi College of Information Engineering Yangzhou University Yangzhou 225009 P. R. China

A robust dissipative control problem for a class of It-type stochastic systems is discussed with Markovian jumping parameters and time-varying delay. A memoryless state feedback dissipative controller is developed based on Lyapunov-Krasovskii functional approach such that the closed-loop system is robustly stochastically stable and weakly delay-dependent （RSSWDD） and strictly （Q, S, R）-dissipative. The sufficient condition on the existence of state feedback dissipative controller is presented by linear matrix inequality （LMI）. And the desired controller can be concluded as solving a set of LMI. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach.

关键词： Ito-type stochastic system time-varying delay Markovprocess dissipative control robustly stochastically stable andweakly delay-dependent (RSSWDD) linear matrix inequality.

QSobel:A novel quantum image edge extraction algorithm

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Science China(Information Sciences) 2015年第1期58卷 107-119页

作者： zhang yi LU Kai GAO yingHui Science and Technology on Parallel and Distributed Processing Laboratory National University of Defense Technology College of Computer National University of Defense Technology College of Electronic Science and Engineering National University of Defense Technology

Edge extraction is an indispensable task in digital image processing. With the sharp increase in the image data, real-time problem has become a limitation of the state of the art of edge extraction *** this paper, QSobel, a novel quantum image edge extraction algorithm is designed based on the flexible representation of quantum image(FRQI) and the famous edge extraction algorithm Sobel. Because FRQI utilizes the superposition state of qubit sequence to store all the pixels of an image, QSobel can calculate the Sobel gradients of the image intensity of all the pixels simultaneously. It is the main reason that QSobel can extract edges quite fast. Through designing and analyzing the quantum circuit of QSobel, we demonstrate that QSobel can extract edges in the computational complexity of O(n2) for a FRQI quantum image with a size of2 n × 2n. Compared with all the classical edge extraction algorithms and the existing quantum edge extraction algorithms, QSobel can utilize quantum parallel computation to reach a significant and exponential ***, QSobel would resolve the real-time problem of image edge extraction.

关键词： edge extraction quantum image processing FRQI Sobel computational complexity

A Hazard Analysis-based Approach to Improve the Landing Safety of a BWB Remotely Piloted Vehicle

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Chinese Journal of Aeronautics 2012年第6期25卷 846-853页

作者： LU yi zhang Shuguang LI Xueqing Airworthiness Technologies Research Center Beihang University Beijing 100191 China

The BUAA-BWB remotely piloted vehicle （RPV） designed by our research team encountered an unexpected landing safety problem in flight tests. It has obviously affected further research project for blended-wing-body （BWB） aircraft configuration characteristics. Searching for a safety improvement is an urgent requirement in the development work of the RPV. In view of the vehicle characteristics, a new systemic method called system-theoretic process analysis （STPA） has been tentatively applied to the hazardous factor analysis of the RPV flight test. An uncontrolled system behavior ＂path sagging phenomenon＂ is identified by implementing a three degrees of freedom simulation based on wind tunnel test data and establishing landing safety system dynamics archetype. To obtain higher safety design effectiveness and considering safety design precedence, a longitudinal ＂belly-flap＂ control surface is innovatively introduced and designed to eliminate hazards in landing. Finally, flight tests show that the unsafe factor has been correctly identified and the landing safety has been efficiently improved.

关键词： BWB RPV landing safety STPA system dynamics safety design precedence sagging phenomenon belly-flap

Obstacle avoidance method of three-dimensional obstacle spherical cap

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Journal of Systems Engineering and Electronics 2018年第5期29卷 1058-1068页

作者： YANG Xiuxia zhang yi ZHOU Weiwei Naval Aviation University Yantai 264001China

Focusing on obstacle avoidance in three-dimensional space for unmanned aerial vehicle(UAV), the direct obstacle avoidance method in dynamic space based on three-dimensional velocity obstacle spherical cap is proposed, which quantifies the influence of threatening obstacles through velocity obstacle spherical cap parameters. In addition, the obstacle avoidance schemes of any point on the critical curve during the multi-obstacles avoidance are given. Through prediction, the insertion point for the obstacle avoidance can be obtained and the flight path can be replanned. Taking the Pythagorean Hodograph(PH) curve trajectory re-planning as an example, the three-dimensional direct obstacle avoidance method in dynamic space is tested. Simulation results show that the proposed method can realize the online obstacle avoidance trajectory re-planning, which increases the flexibility of obstacle avoidance greatly.

关键词： three-dimensional direct space obstacle avoidance velocity obstacle cone velocity obstacle spherical cap

Dual loop feedback pre-distortion in satellite communication

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Journal of Systems Engineering and Electronics 2013年第4期24卷 586-591页

作者： Chengkai Tang Baowang Lian yi zhang School of Electronics and Information Northwestern Polytechnical University

Since the satellite communication goes in the trend of high-frequency and fast speed, the coefficients updating and the precision of the traditional pre-distortion feedback methods need to be further improved. On this basis, this paper proposes dual loop feedback pre-distortion, which uses two first-order Volterra filter models to reduce the computing complexity and a dynamic error adjustment model to construct a revised feedback to ensure a better pre-distortion performance. The computation complexity, iterative convergence speed and precision of the proposed method are theoretically analyzed. Simulation results show that this dual loop feedback pre-distortion can speed the updating of coefficients and ensure the linearity of the amplifier output.

关键词： satellite communication pre-distortion Volterra filter dual loop feedback mean square error.

Distributed Model Predictive Load Frequency Control of Multi-area Power System with DFIGs

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IEEE/CAA Journal of Automatica Sinica 2017年第1期4卷 125-135页

作者： yi zhang Xiangjie Liu Bin Qu Department of Electrical Engineering North China University of Science and Technology State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University

Reliable load frequency control LFC is crucial to the operation and design of modern electric power systems. Considering the LFC problem of a four-Area interconnected power system with wind turbines, this paper presents a distributed model predictive control DMPC based on coordination scheme. The proposed algorithm solves a series of local optimization problems to minimize a performance objective for each control area. The generation rate constraints GRCs, load disturbance changes, and the wind speed constraints are considered. Furthermore, the DMPC algorithm may reduce the impact of the randomness and intermittence of wind turbine effectively. A performance comparison between the proposed controller with and without the participation of the wind turbines is carried out. Analysis and simulation results show possible improvements on closed-loop performance, and computational burden with the physical constraints. © 2014 Chinese Association of Automation.

关键词： Asynchronous generators Electric control equipment Electric fault currents Electric frequency control Electric load management Electric power systems Model predictive control Optimization Press load control Wind Wind turbines

General moving objects recognition method based on graph embedding dimension reduction algorithm

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 976-984页

作者： yi zhang Jie YANG Kun LIU Institute of Image Processing and Pattern Recognition Shanghai Jiao Tong University Shanghai 200240 China

Effective and robust recognition and tracking of objects are the key problems in visual surveillance systems. Most existing object recognition methods were designed with particular objects in mind. This study presents a general moving objects recognition method using global features of targets. Targets are extracted with an adaptive Gaussian mixture model and their silhouette images are captured and unified. A new objects silhouette database is built to provide abundant samples to train the subspace feature. This database is more convincing than the previous ones. A more effective dimension reduction method based on graph embedding is used to obtain the projection eigenvector. In our experiments, we show the effective performance of our method in addressing the moving objects recognition problem and its superiority compared with the previous methods.

关键词： Moving objects recognition Adaptive Gaussian mixture model Principal component analysis Linear discriminant analysis Marginal Fisher analysis