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Changes of Precipitation Infiltration Recharge in the Circumstances of Coal Mining Subsidence in the shen-dong Coal Field,China

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Acta Geologica Sinica(English Edition) 2012年第4期86卷 993-1003页

作者： ZHANG Fawang SONG Yaxin ZHAO Hongmei HAN Zhantao WANG dong Institute of Hydrogeology and Environmental Geology CAGS Institute of Karst Geology CAGS/Karst Dynamics LaboratoryMinistry of Land and Resources Non-ferrous Metal Geological Survey Center

Coal mining subsidence is a universal environmental-geological problem in mining areas. By selecting the shen-dong coal mining subsidence area as the research field, this paper studies the changes in precipitation infiltration recharge in the circumstances of coal mining subsidence by means of field geological investigation and laboratory simulation experiments, which is expected to provide a scientific basis for eco-environmental restoration in the mining area. The results indicate that at the unstable stage of subsidence, three types of subsidence in the shen-dong mining area have positive effects on the precipitation infiltration recharge, and the type of full-thickness bedrock subsidence has the greatest influence. In the stable stage of subsidence, the precipitation infiltration process after long- term drought and the moisture migration in the aeration zone undergo three different stages： evaporation-infiltration before precipitation, infiltration-upward infiltration-infiltration during precipitation and evaporation-infiltration after precipitation. During a heavy rainfall infiltration process, the wetting front movement in fine sand, coarse sand and dualistic structure of fine-coarse sand consists of two stages： the stage of wetting front movement during precipitation, in which the wetting front movement distance has linear relationship with the depth, and the stage of wetting front movement after precipitation, in which the wetting front movement distance has the power function relationship with the depth. The wetting front movement velocity is influenced by the rainfall amount and the lithology in the aeration zone. However, as the depth increases, the movement velocity will decay exponentially.

关键词： precipitation infiltration simulation coal mining subsidence shen-dong mining area

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Stochastic Iterative Learning Control With Faded Signals

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1196-1208页

作者： Ganggui Qu dong shen the College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China

Stochastic iterative learning control(ILC) is designed for solving the tracking problem of stochastic linear systems through fading channels. Consequently, the signals used in learning control algorithms are faded in the sense that a random variable is multiplied by the original signal. To achieve the tracking objective, a two-dimensional Kalman filtering method is used in this study to derive a learning gain matrix varying along both time and iteration axes. The learning gain matrix minimizes the trace of input error covariance. The asymptotic convergence of the generated input sequence to the desired input value is strictly proved in the mean-square sense. Both output and input fading are accounted for separately in turn, followed by a general formulation that both input and output fading *** examples are provided to verify the effectiveness of the proposed schemes.

关键词： Fading channels iterative learning control (ILC) Kalman filtering, mean-square convergence stochastic systems

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Enhancing Iterative Learning Control With Fractional Power Update Law

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1137-1149页

作者： Zihan Li dong shen Xinghuo Yu the School of Mathematics Renmin University of ChinaBeijing 100872China the School of Engineering RMIT UniversityMelbourne VIC 3001Australia

The P-type update law has been the mainstream technique used in iterative learning control(ILC)systems,which resembles linear feedback control with asymptotical *** recent years,finite-time control strategies such as terminal sliding mode control have been shown to be effective in ramping up convergence speed by introducing fractional power with *** this paper,we show that such mechanism can equally ramp up the learning speed in ILC *** first propose a fractional power update rule for ILC of single-input-single-output linear systems.A nonlinear error dynamics is constructed along the iteration axis to illustrate the evolutionary converging *** the nonlinear mapping approach,fast convergence towards the limit cycles of tracking errors inherently existing in ILC systems is *** limit cycles are shown to be tunable to determine the steady *** simulations are provided to verify the theoretical results.

关键词： Asymptotic convergence convergence rate finiteiteration tracking fractional power learning rule limit cycles

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A Two-Dimensional Approach to Iterative Learning Control with Randomly Varying Trial Lengths

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Journal of Systems Science & Complexity 2020年第3期33卷 685-705页

作者： LIU Chen shen dong WANG Jinrong College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China School of Mathematics Renmin University of ChinaBeijing 100872China Department of Mathematics Guizhou UniversityGuiyang 550025China School of Mathematical Sciences Qufu Normal UniversityQufu 273165China

In this paper,iterative learning control(ILC)is considered to solve the tracking problem of time-varying linear stochastic systems with randomly varying trial *** the two-dimensional Kalman filtering technique,the authors can establish a recursive framework for designing the learning gain matrix along both time and iteration axes by optimizing the trace of input error covariance *** is strictly proved that the input error converges to zero asymptotically in mean square sense and thus the tracking error covariance *** extensions to that prior distribution of nonuniform trial lengths is unknown are also investigated with an asymptotical estimation *** simulations are provided to verify the effectiveness of the proposed framework.

关键词： Iterative learning control Kalman filtering recursive estimation varying trial lengths

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Iterative Learning Control With Incomplete Information： A Survey

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IEEE/CAA Journal of Automatica Sinica 2018年第5期5卷 885-901页

作者： dong shen Senior Member IEEE ieee beijing university of chemical technology

Abstract--This paper conducts a survey on iterative learn- ing control （ILC） with incomplete information and associated control system design, which is a frontier of the ILC field. The incomplete information, including passive and active types, can cause data loss or fragment due to various factors. Passive incomplete information refers to incomplete data and information caused by practical system limitations during data collection, storage, transmission, and processing, such as data dropouts, delays, disordering, and limited transmission bandwidth. Active incomplete information refers to incomplete data and information caused by man-made reduction of data quantity and quality on the premise that the given objective is satisfied, such as sampling and quantization. This survey emphasizes two aspects： the first one is how to guarantee good learning performance and tracking performance with passive incomplete data, and the second is how to balance the control performance index and data demand by active means. The promising research directions along this topic are also addressed, where data robustness is highly emphasized. This survey is expected to improve understanding of the restrictive relationship and trade-off between incomplete data and tracking performance, quantitatively, and promote further developments of ILC theory. Index Terms--Data dropout, data robustness, incomplete in- formation, iterative learning controi（ILC）, quantized control, sampled control, varying lengths.

关键词： Data dropout data robustness incomplete information iterative learning control(ILC) quantized control sampled control varying lengths

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Manufacture and Performance of Ionic Polymer-Metal Composites

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Journal of Bionic Engineering 2007年第3期4卷 143-149页

作者： Min Yu Hui shen Zhen-dong Dai Institute of Bio-inspired Structure and Surface Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China

Ion-exchange Polymer Metal Composites （IPMC） are a new class of intelligent material that can be used effectively as actuators and artificial muscles. IPMC was fabricated and its displacement and force characteristics were investigated with respect to voltage, frequency and waveform of the controlling signal. A square waveform input generated slightly larger displacement and force than sinusoidal or triangular waveform. When the voltage was increased and the frequency was decreased, displacement and force were both increased. However, although the bending deformation of IPMC was large, the output force was much lower than we expected. Improvement of the force output is key and is the main obstacle to be overcome in order to make IPMC of practical use.

关键词： IPMC artificial muscle

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Iterative Learning Control for Discrete-time Stochastic Systems with Quantized Information

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IEEE/CAA Journal of Automatica Sinica 2016年第1期3卷 59-67页

作者： dong shen Yun Xu IEEE College of Information Science and Technology Beijing University of Chemical Technology

An iterative learning control (ILC) algorithm using quantized error information is given in this paper for both linear and nonlinear discrete-time systems with stochastic noises. A logarithmic quantizer is used to guarantee an adaptive improvement in tracking performance. A decreasing learning gain is introduced into the algorithm to suppress the effects of stochastic noises and quantization errors. The input sequence is proved to converge strictly to the optimal input under the given index. Illustrative simulations are given to verify the theoretical analysis. © 2014 Chinese Association of Automation.

关键词： Algorithms Digital control systems Discrete time control systems Iterative methods Learning algorithms Stochastic control systems Stochastic systems

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Convergence analysis of ILC input sequence for underdetermined linear systems

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Science China(Information Sciences) 2017年第9期60卷 305-307页

作者： dong shen Jian HAN Youqing WANG College of Information Science and Technology Beijing University of Chemical Technology

Dear editor,Iterative learning control(ILC)is a kind of intelligent control strategy,applied to those systems that could complete a given task over a finite time interval and repeat it again and *** introduced in 1984,it has gained fast developments during the past three decades[1].In order to analyze the tracking performance of ILC,it is conventional to prove that the actual input sequence converges to the desired input along the iteration axis in most

关键词： In Convergence analysis of ILC input sequence for underdetermined linear systems ILC

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Zero-Error Convergence of Iterative Learning Control Using Uniform Quantizer with Encoding and Decoding Method 36

Zero-Error Convergence of Iterative Learning Control Using U...

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第36届中国控制会议

作者： Chao Zhang dong shen College of Information Science and Technology Beijing University of Chemical Technology

ISBN: (纸本)9781538629185

In this paper,the iterative learning control problem using uniform quantizer with encoding and decoding scheme is considered,in which the system output is transformed and encoded firstly,and then transmitted back to the controller and decoded for input ***-error convergence of the output to the desired reference is realized by utilizing this updating *** results are extended to affine nonlinear systems and a numerical example is provided to demonstrate the effectiveness of the proposed scheme.

关键词： Iterative Learning Control Uniform Quantizer Encoding and Decoding

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Simulation and analysis of co-phasing errors of the segmented primary mirror tiled by hexagonal segments in LOT

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Research in Astronomy and Astrophysics 2021年第10期21卷 37-45页

作者： Shi-dong shen Xiang-Qun Cui Yong Zhang National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China University of the Chinese Academy of Sciences Beijing 100049China

In this paper,co-phasing errors of a segmented primary mirror tiled by hexagonal segments are successfully calculated for the 12-meter Large aperture Optical/infrared Telescope(LOT).Co-phasing errors including out-of-plane errors are simulated separately and comprehensively based on several software simulation *** simulation results show that the Strehl Ratio(SR)of LOT is larger than 0.8 when the RMS value of tip-tilt obeying a normal distribution is less than 0.018 arcsec,and the SR of LOT is larger than 0.8 when the RMS value of piston obeying a normal distribution is less than 40 ***,simulation results of Zemax show that the SR of LOT is larger than 0.8 when the RMS value of tip-tilt obeying a normal distribution is less than 0.02 arcsec,and the SR of LOT is larger than 0.8 when the RMS value of piston obeying a normal distribution is less than 40 *** simulation results successfully lay a solid foundation for LOT(especially the segmented primary mirror with active optics).

关键词： methods:analytical techniques:miscellaneous telescopes

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