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An Adaptive Local Grid Nesting-based Genetic Algorithm for Multi-earth Observation Satellites' Area Target Observation

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Journal of Systems Science and Systems Engineering 2024年第2期33卷 232-258页

作者： ligang Xing Wei Xia Xiaoxuan Hu Waiming Zhu Yi wu School of Management Hefei University of TechnologyHefei 230009China Key Laboratory of Process Optimization and Inteligent Decision-making Ministry of EducationHefei 230009China Intelligent Interconnected Systems Laboratory of Anhui Province Hefei 230009China

The Scheduling of the Multi-EOSs Area Target Observation(SMEATO)is an EOS resource schedul-ing problem highly coupled with computational geometry.The advances in EOS technology and the ex-pansion of wide-area remote sensing applications have increased the practical significance of SMEATO.In this paper,an adaptive local grid nesting-based genetic algorithm(ALGN-GA)is proposed for developing SMEATO solutions.First,a local grid nesting(LGN)strategy is designed to discretize the target area into parts,so as to avoid the explosive growth of calculations.A genetic algorithm(GA)framework is then used to share reserve information for the population during iterative evolution,which can generate high-quality solutions with low computational costs.On this basis,an adaptive technique is introduced to determine whether a local region requires nesting and whether the grid scale is sufficient.The effectiveness of the proposed model is assessed experimentally with nine randomly generated tests at different scales.The results show that the ALGN-GA offers advantages over several conventional algorithms in 88.9%of instances,especially in large-scale instances.These fully demonstrate the high efficiency and stability of the ALGN-GA.

关键词： Multi-EOSs scheduling area target observation adaptive genetic algorithm local grid nesting

The reformation of catalyst:From a trial-and-error synthesis to rational design

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Nano Research 2024年第4期17卷 3261-3301页

作者： ligang Wang Jiabin wu Shunwu Wang Huan Liu Yao Wang Dingsheng Wang Department of Chemistry Tsinghua UniversityBeijing 100084China

The appropriate catalysts can accelerate the reaction rate and effectively boost the efficient conversion of various molecules,which is of great importance in the study of chemistry,chemical industry,energy,materials and environmental science.Therefore,efficient,environmentally friendly,and easy to operate synthesis methods have been used to prepare various types of catalysts.Although previous studies have reported the synthesis and characterization of the aforementioned catalysts,more still remain in trial and error methods,without in-depth consideration and improvement of traditional synthesis methods.Here,we comprehensively summarize and compare the preparation methods of the trial-and-error synthesis strategy,structure–activity relationships and density functional theory(DFT)guided catalysts rational design for nanomaterials and atomically dispersed catalysts.We also discuss in detail the utilization of the nanomaterials and single atom catalysts for converting small molecules(H_(2)O,O_(2),CO_(2),N_(2),etc.)into value-added products driven by electrocatalysis,photocatalysis,and thermocatalysis.Finally,the challenges and outlooks of mass preparation and production of efficient and green catalysts through conventional trial and error synthesis and DFT theory are featured in accordance with its current development.

关键词： trial-and-error synthesis structure–activity relationships density functional theory(DFT)guidance nanomaterials atomically dispersed catalysts

Sliding Mode Control in Power Converters and Drives: A Review

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IEEE/CAA Journal of Automatica Sinica 2022年第3期9卷 392-406页

作者： ligang wu Jianxing Liu Sergio Vazquez Sudip K.Mazumder IEEE Department of Control Science and Engineering Harbin Institute of TechnologyHarbin 150001China Electronic Engineering Department Universidad de Sevilla41092 SevillaSpain Electrical and Computer Engineering Department University of Illinois ChicagoChicagoIL 60607 USA

Sliding mode control(SMC)has been studied since the 1950s and widely used in practical applications due to its insensitivity to matched disturbances.The aim of this paper is to present a review of SMC describing the key developments and examining the new trends and challenges for its application to power electronic systems.The fundamental theory of SMC is briefly reviewed and the key technical problems associated with the implementation of SMC to power converters and drives,such chattering phenomenon and variable switching frequency,are discussed and analyzed.The recent developments in SMC systems,future challenges and perspectives of SMC for power converters are discussed.

关键词： Motor drive power electronics systems sliding mode control

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Event-based sliding mode control under denial-of-service attacks

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Science China(Information Sciences) 2022年第6期65卷 125-141页

作者： Yingxin TIAN Xiang LI Bo DONG Yabin GAO ligang wu Department of Control Science and Engineering Harbin Institute of Technology School of Software Harbin Institute of Technology

This paper deals with the problem of estimator-based sliding mode control against denial-of-service(DoS) attacks and discrete events via a time-delay approach. A networked system is considered an uncertain dynamical system with matched and mismatched perturbations and exogenous disturbance in the network environment. A network-resource-aware event-triggering mechanism is designed with aperiodically releasing system measurements. Furthermore, to describe the DoS attack duration and inter-event time, a time-delay modeling approach considers the DOS attack duration and inter-event time as a “time delay” of the measurements between the sensor and controller over the network is proposed. Consequently, an intervaltime-delay system with uncertainties is formulated. A state-observer-based sliding mode controller, by which the ideal sliding mode can be achieved, is proposed against the DoS attacks. The resulting sliding motion is proved to be robust and stable with an Lgain performance. Finally, the effectiveness and applicability of the present sliding mode control are validated in a simulated pendulum system.

关键词： sliding mode control time delay uncertain system state observer event trigger

Phase and chemical state tuning of FeNi oxides for oxygen evolution reaction

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Science China Chemistry 2024年第8期 2755-2766页

作者： Jiawei wu Zhouyang Ma Lice Yu Shuli Wang Fulin Yang ligang Feng School of Chemistry and Chemical Engineering Yangzhou University

Advancing and deploying the Fe Ni-based catalyst, the state-of-the-art pre-electrocatalysts, for oxygen evolution reactions（OER）still suffer from unclear chemical state correlation to the catalytic ability, as evidenced by the variedly reported performance for the different Fe Ni structures. Herein, we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor. Driven by the complicated and compromised atmosphere, namely, the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe2O3and FeNi3alloy, and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples. The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states, and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier. The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.

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Multi-UAV Synchronous Approaching Using Homotopy-Based Trajectory Planning

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Guidance, Navigation and Control 2022年第2期2卷 99-124页

作者： Weiran Yao Yang Chen Haoyu Tian Chengwei wu ligang wu School of Astronautics Harbin Institute of Technology Harbin 150001P.R.China College of Intelligent Systems Science and Engineering Harbin Engineering University Harbin 150001P.R.China

Synchronous approaching is an important capability for autonomous cooperation of multiple unmanned aerial vehicles(UAVs).In this paper,a homotopy-based trajectory planning method is presented for the multi-UAV synchronous approaching problem.A homotopic trajectory description is employed to construct the trajectory solution space of the UAVs.A novel onionlike homotopy structure is proposed to decouple the performance indexes of the trajectory planning problem.Local trajectory homotopy structures are designed based on the detouring model and the hovering model of UAV.The optimal trajectories for synchronous approaching are searched within the homotopy structures.Simulation results show how synchronous the UAVs are,by using the proposed homotopy-based trajectory planning method.

关键词： Multi-UAV synchronous approaching homotopic method trajectory planning

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基于轻量化神经网络的石窟壁画破损检测方法

信息与控制 2024年第1期53卷 108-119页

作者：吴利刚张梁山西大同大学机电工程学院山西大同037003 山西大同大学煤炭工程学院山西大同037003 大连海事大学信息科学与技术学院辽宁大连116026

针对石窟壁画脱落与破损检测过程中存在检测精度低、实时性差的问题,提出了基于轻量化神经网络和多重注意力机制的石窟壁画破损检测方法。首先,引入Ghost Conv完成轻量化特征提取,降低模型复杂度;其次,加入双重注意力机制增加特征提取... 详细信息

针对石窟壁画脱落与破损检测过程中存在检测精度低、实时性差的问题,提出了基于轻量化神经网络和多重注意力机制的石窟壁画破损检测方法。首先,引入Ghost Conv完成轻量化特征提取,降低模型复杂度;其次,加入双重注意力机制增加特征提取的倾向性,加快模型收敛速度;最后,使用加权双向特征金字塔拼接方式高效融合特征信息,通过复合缩放完成预测。实验结果表明:改进后的算法网络层数减少了34.40%。参数量和浮点运算量分别降低了62.98%和68.77%,模型体积压缩了62.78%。检测精度高达64.7%,实时检测速度从63.60帧/s提升至97.56帧/s,提高了约53.39%。

关键词：深度学习神经网络轻量化模型注意力机制壁画破损检测

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Integral sliding mode control design for nonlinear stochastic systems under imperfect quantization

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Science China(Information Sciences) 2017年第12期60卷 71-81页

作者： Yabin GAO Wensheng LUO Jianxing LIU ligang wu Research Institute of Intelligent Control and Systems Harbin Institute of Technology

This paper presents a sliding mode control(SMC) scheme via output-feedback approach for It?o stochastic systems under a quantization mechanism. The quantization process is formulated with the imperfection that random packet loss occurs at the logarithmic quantizer. A Luenberger observer is designed, based on the packet loss rate and the imperfect quantized measurement. A novel SMC law is synthesized by utilization of an integral sliding surface. The stochastic stability of the resulting closed-loop system is analyzed in terms of Lyapunov stability, and a set of solvable matrix inequalities are established for practical application requirements. Finally, a simulation example is employed for the illustration of the effectiveness of the presented control scheme.

关键词： stochastic systems quantized control sliding mode control observer design packet loss

基于改进YOLOv7-seg的黄花菜检测与分割方法

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农业工程学报 2024年第9期40卷 146-153页

作者：姚涛谈志鹏程娥吴利刚山西大同大学机电工程学院大同037003 河北工业大学机械工程学院天津300130

目标检测与分割是实现黄花菜智能化采摘的关键技术,原始目标检测算法容易出现漏检、误检等问题,无法满足自然环境下生长的黄花菜采摘要求。该研究提出一种基于改进YOLOv7-seg的黄花菜目标检测与实例分割算法模型(YOLO-Daylily)。通过在Y... 详细信息

目标检测与分割是实现黄花菜智能化采摘的关键技术,原始目标检测算法容易出现漏检、误检等问题,无法满足自然环境下生长的黄花菜采摘要求。该研究提出一种基于改进YOLOv7-seg的黄花菜目标检测与实例分割算法模型(YOLO-Daylily)。通过在YOLOv7-seg骨干网络(backbone)中引入CBAM(convolutional block attention module)注意力机制模块,降低背景等干扰因素的影响;在ELAN(efficient layer aggregation networks)模块中采用PConv(partial convolution)替换原有的3×3卷积层,减少冗余计算和内存访问,提升对目标黄花菜特征提取的能力。颈部网络(neck)采用坐标卷积(CoordConv)替换PA-FPN(path aggregation-feature pyramid networks)中1×1卷积层,增强模型对位置的感知,提高掩膜(mask)鲁棒性。在改进的PA-FPN结构中采用残差连接方法将浅层特征图几何信息与深层特征图语义信息特征相结合,提高模型对目标黄花菜的检测分割性能。消融试验表明:改进后的模型检测准确率、召回率和平均精度分别达到92%、86.5%、93%,相比YOLOv7-seg基线模型分别提升2.5、2.3、2.7个百分点;分割准确率、召回率和平均精度分别达到92%、86.7%、93.5%,比基线模型分别提升0.2、3.5、3个百分点。与Mask R-CNN、SOLOv2、YOLOV5-seg、YOLOv5x-seg算法相比,平均精度分别提升8.4、12.7、4.8、5.4个百分点。改进后的模型减少了漏检、误检等情况,对目标定位更加精准,为后续黄花菜智能化采摘实际应用提供理论支持。

关键词：图像处理机器视觉目标检测深度学习 YOLOv7 实例分割黄花菜

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