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SSRN 2023年

作者： Gao, Haishu Zhang, Feng State Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan250061 China

Traditionally virtual inertia is the control strategy of wind turbines when participating in frequency regulation. However, it has inherent defects in measurement error amplification, due to the frequency differential, and it may incur large response power deviation or even inverse response. Also, when control delay of wind turbines is taken into consideration, virtual inertia is essentially a kind of fast power response, just the same as droop control of wind turbines. Hence, considering the reliability of droop control, it’s valuable to explorer a novel droop control method without virtual inertia, as the frequency response model of wind turbines. For this reason, a multi-segment droop control strategy was proposed to provide a reliable frequency regulation model for wind turbines, which can be broadly applied in other inverter-based power sources. Firstly, based on the extended system frequency response (SFR) model, a differential equation including piecewise time-varying coefficient was established to analyze the frequency response of the presented strategy. To deal with impulse function emerged during the deduction, the impulse function balancing principle and the integration by parts algorithm were adopted. Then the analytical expression of the frequency response with multi-segment droop control strategy can be obtained. Subsequently, based on analytical expression, the performance of multi-segment droop control strategy was theoretically analyzed via comparison with traditional virtual inertia control, and meanwhile the conclusion that the presented multi-segment droop control has better frequency regulation performance can be got. Furthermore, to achieve optimal frequency regulation performance, a Lagrangian function was established to get the optimal parameters of the proposed control strategy, according to the relationship between the frequency nadir and frequency regulation parameters. During its solution, the exponential homotopy algorithm was adopted. F

关键词： Wind turbines

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Forming Circle Formations of Multi-agent systems Under Actuator Faults 5th

Forming Circle Formations of Multi-agent Systems Under Actu...

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5th Chinese Conference on Swarm Intelligence and Cooperative control, CCSICC 2021

作者： Liu, Jiajun Ru, Xinfeng Xia, Weiguo Wang, Chen China National Aeronautical Radio Electronic Research Institute and National Key Laboratory of Science and Technology on Avionics System Integration Shanghai China Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education and School of Control Science and Engineering Dalian University of Technology Dalian China National Engineering Research Center of Software Engineering and the State Key Laboratory of Turbulence and Complex Systems Intelligent Biomimetic Design Lab College of Engineering Peking University Beijing China

ISBN: (纸本)9789811939976

A distributed fault-tolerant formation control law is designed in this paper for multi-agent systems under external disturbances and actuator faults including time-varying loss of effectiveness faults. The initial position of each agent is already on a circle and the control purpose is to form a desired formation on this circle. Based on this local information, a distributed adaptive formation control law is designed by employing the congelation of variables method to deal with time-varying actuator faults. Finally, a simulation example is given to verify the effectiveness of the adaptive fault-tolerant control design method. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Multi agent systems

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Bearing-Based Target Entrapping control of Multiple Uncertain Agents With Arbitrary Maneuvers

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IFAC-PapersOnLine 2023年第2期56卷 8821-8826页

作者： Haifan Su Ziwen Yang Shanying Zhu Cailian Chen Wenbin Yu Department of Automation Shanghai Jiao Tong University China Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai Engineering Research Center of Intelligent Control and Management

This paper is concerned with bearing-based cooperative target entrapping control of multiple uncertain agents with arbitrary maneuvers including shape deformation, rotations, scalings, etc. A leader-follower structure is used, where the leaders move with the predesigned trajectories, and the followers are steered by an estimation-based control method, integrating a distance estimator using bearing measurements and a stress matrix-based formation controller. The signum functions are used to compensate for the uncertainties so that the agents’ accelerations can be piecewise continuous and bounded to track the desired dynamics. With proper design of the leaders’ trajectories and a geometric configuration, an affine matrix is determined so that the inter-agent relative bearings can be persistently exciting since the bearing rates are related to different weighted combinations of the affine matrix vectors. The asymptotic convergence of the estimation and control error is proved using Filipov properties and cascaded system theories. A sufficient condition for inter-agent collision avoidance is also proposed. Finally, simulation results are given to validate the effectiveness of the method.

关键词： Target entrapping control bearing measurement persistent excitation uncertainty

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Image Segmentation Based on Improved Wavelet Transform

Image Segmentation Based on Improved Wavelet Transform

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第35届中国控制与决策会议

作者： Guowu Zhu Lixiang Ma Bingyou Liu Pan Yang College of Electrical Engineering Anhui Polytechnic University Key Laboratory of Advanced Perception and Intelligent Control of High-End Equipment Ministry of Education Anhui Institute of Information Technology College of Electrical Engineering Anhui Polytechnic University Key Laboratory of Advanced Perception and Intelligent Control of High-End EquipmentMinistry of Education Anhui Dar Intelligent Control System Stock Co. Ltd

In order to preserve the effective information of the image and segment it better,an image segmentation method based on improved wavelet transform is ***,the image is decomposed based on wavelet transform to obtain the horizontal,vertical and diagonal information of the ***,the peak and valley points are determined by the decomposed wavelet coefficients,and the segmentation threshold is ***,the experimental results show that the improved wavelet transform segmentation method proposed in this paper has better segmentation effect than the traditional segmentation method.

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Comprehensive study of the ultrafast photoexcited carrier dynamics in Sb_(2)Te_(3)–GeTe superlattices

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Chinese Physics B 2024年第7期33卷 381-387页

作者：叶之江金钻明蒋叶昕卢琦贾梦辉钱冬黄夏敏李舟彭滟朱亦鸣 Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation CenterShanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 200092China Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) Shenyang National Laboratory for Materials ScienceSchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China GBA Branch of Aerospace Information Research Institute Chinese Academy of SciencesGuangzhou 510700China Guangdong Provincial Key Laboratory of Terahertz Quantum Electromagnetics Guangzhou 510700China University of Chinese Academy of Sciences Beijing 100039China

Chalcogenide superlattices Sb_(2)Te_(3)-GeTe is a candidate for interfacial phase-change memory(iPCM) data storage *** employing terahertz emission spectroscopy and the transient reflectance spectroscopy together,we investigate the ultrafast photoexcited carrier dynamics and current transients in Sb_(2)Te_(3)-GeTe *** orientation and excitation polarization dependences of the THz emission confirm that ultrafast thermo-electric,shift and injection currents contribute to the THz generation in Sb_(2)Te_(3)-GeTe *** decreasing the thickness and increasing the number of GeTe and Sb_(2)Te_(3) layer,the interlayer coupling can be enhanced,which significantly reduces the contribution from circular photo-galvanic effect(CPGE).A photo-induced bleaching in the transient reflectance spectroscopy probed in the range of~1100 nm to~1400 nm further demonstrates a gapped state resulting from the interlayer *** demonstrates play an important role in the development of iPCM-based high-speed optoelectronic devices.

关键词： Sb_(2)Te_(3)/GeTe superlattices ultrafast carrier dynamics interfacial phase change memory THz emission spectroscopy transient reflectance spectroscopy

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HIGH-PRECISION AND SYNCHRONIZED WIDEBAND MEASUREMENT TECHNOLOGY AND ITS APPLICATIONS 10

HIGH-PRECISION AND SYNCHRONIZED WIDEBAND MEASUREMENT TECHNOL...

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10th Renewable Power Generation Conference, RPG 2021

作者： Jin, Zongshuai Zhang, Hengxu Shi, Fang Sun, Yuanyuan Wei, Mingjie Key Laboratory of Power System Intelligent Dispatch and Control of the Ministry of Education Shandong University Jinan250061 China

ISBN: (纸本)9781839536069

To enhance the monitoring capability of the operation situation in wide frequency band of power systems integrated with large-scale power electronic devices, the wideband synchronized measurement unit (WMU) has been developed using the embedded DSP-FPGA computing module based on fast noise filter and fast tuning TFT wideband measurement algorithm. The WMU has been integrated with 5G communication technology, which can meet the communication needs of multi scenarios. The high-speed transmission of wideband measurement data is realized using the optical fiber communication and 5G/4G wireless communication. The potential applications of WMU mainly include the wideband oscillation monitoring, the wideband parameter identification, the wideband disturbance localization, the high-precision power quality assessment, the wideband feature driven fault identification, the post-mortem wideband disturbance analysis, and the wideband transfer characteristics testing of electrical devices. © The Institution of Engineering and Technology.

关键词： Optical fiber communication

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Calculation method of steady-state fault current for offshore wind farm 7

Calculation method of steady-state fault current for offshor...

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2021 7th International Conference on Manufacturing Technology and Applied Materials, ICAMMT 2021

作者： Miao, Weiying Gao, Houlei Xu, Bin Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan250061 China

In order to improve the efficiency of solving the steady-state fault current of the offshore wind farm current collection system, In this method, the equivalent model of the PMSG and the VF control converter is established by taking into account the low-voltage ride-through in the case of failure. The Newton-Raphson method is used to iteratively calculate the fault equivalent network. By establishing a simulation model under PSCAD, the symmetric and asymmetrical faults in the collector system of a grid-connected permanent magnet wind turbine connected to the VSC-HVDC are simulated. Simulation results verify the effectiveness and accuracy of the calculation method. © Published under licence by IOP Publishing Ltd.

关键词： Offshore wind farms

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Efficient Reinforcement Learning for 3D LiDAR Navigation of Mobile Robot 41

Efficient Reinforcement Learning for 3D LiDAR Navigation of ...

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第41届中国控制会议

作者： Yu Zhai Zhe Liu Yanzi Miao Hesheng Wang China University of Mining and Technology MoE Key Lab of Artificial Intelligence Shanghai Jiao Tong University Department of Automation Key Laboratory of System Control and Information Processing of Ministry of EducationShanghai Engineering Research Center of Intelligent Control and ManagementShanghai Jiao Tong University

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

Developing an efficient automatic navigation system for mobile robots is challenging in the strange scenarios where robots can only observe the environment of the surrounding limited *** other distributed automatic navigation systems exist,they often require extracting semantic information to calculate navigation action,which requires extra modules to provide perceptual information and is not *** propose an end-to-end automatic navigation system based on the reinforcement learning *** particular,the raw 3 D LiDAR data is used to directly map an efficient navigation *** design a novel dense reward function to handle the reward sparsity issue and provide a graphical representation method to enable the efficient feature learning from the raw 3 D LiDAR data in our navigation *** addition,an imitation learning based policy initialization is introduced before the subsequent reinforcement learning,which increases the learning efficiency and,in the meantime,still encouraging the robot to explore all the potential states to achieve advanced performance than the imitated *** navigation model is trained in the Webots environment and the experimental results show that our model has efficient and flexible navigation performance in complex *** importantly,trained model can be easily extended to unfamiliar environments.

关键词： End-to-end Navigation Mobile robot Reinforcement Learning 3D LiDAR

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Digital-Twin-Based Clock Synchronization in Industrial IoT systems 13

Digital-Twin-Based Clock Synchronization in Industrial IoT S...

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13th IEEE International Conference on CYBER Technology in Automation, control, and intelligent systems, CYBER 2023

作者： Cheng, Ting Liu, Shuai Xu, Qimin Zhu, Shanying Department of Automation Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai200240 China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240 China School of Control Science and Engineering Shandong University Jinan250061 China

ISBN: (纸本)9798350315196

Close and efficient cooperation between devices in the Industrial Internet of Things (IIoT) requires precise clock synchronization as a prerequisite. The uncertainty of IIoT networks and the complexity of industrial environments have led to less precise clock synchronization achieved by traditional algorithms and higher network resource consumption. This paper proposes a digital-twin-based clock synchronization scheme for IIoT systems. By building the digital model for each local clock to predict their clock skew, the information interaction required to achieve synchronization is reduced. In order to model the clock accurately, this paper proposes to use the extended state Kalman filter to handle uncertain dynamics and unknown measurement bias to improve the estimation accuracy of clock skew further. The simulation results show that the proposed algorithm can achieve high- precision clock synchronization while reducing the consumption of network resources. © 2023 IEEE.

关键词： Internet of things

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Recent patents on overflow valve for pressure control

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Recent Patents on Mechanical Engineering 2021年第4期14卷 481-492页

作者： Xie, Baocheng Wang, Yi Zeng, Zhaoqi Gou, Haoliang Zhang, Bing Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin150080 China Beijing Institute of Control Engineering Beijing200085 China

Background: The overflow valve, as an essential pressure control element, is widely applied in various hydraulic transmission systems because of its characteristics of constant pressure overflow, stable pressure, system’s unloading and safety protection. The research on the structure and working principle of the overflow valve is beneficial to improve the working efficiency and operating stability of pressure control of the hydraulic transmission. Therefore, the development trend of the overflow valve for pressure control has been paid more and more attention. Objective: To meet the growing demands for the working efficiency and operating stability of hydraulic transmission, the structure of the overflow valve for pressure control such as direct-acting overflow valve and pilot-operated overflow valve is being improved continuously. Methods: This paper retraces various current representative patents relative to the structural device of direct-acting overflow valve and pilot-operated overflow valve for pressure control. Results: Through investigating a large number of patents on the overflow valve for pressure control, the main existing problems, such as low working efficiency and poor operating stability are summarized and analyzed. Moreover, the development tendency of the overflow valve for pressure control in the future is also discussed. Conclusion: The optimization of the structure of the overflow valve for pressure control is conducive to improve working efficiency and operating stability. More correlative patents will be invented in the future. © 2021 Bentham Science Publishers.

关键词： Efficiency

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