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Model predictive control with fractional-order delay compensation for fast sampling systems

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Science China(Information Sciences) 2021年第7期64卷 165-180页

作者： ze zhou Zhitao LIU Hongye SU Liyan ZHANG State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang University School of Automation Wuhan University of Technology

Model predictive control(MPC) is widely used in fast sampling systems owing to its fast regulating ability. However, the sampling delay is a key issue and tends to be a fractional multiple of the sampling period. If the fractional-order delay is not accurately offset, the controller output will exhibit errors, thus resulting in oscillations in controlled system. Moreover, the MPC delay compensation algorithm is limited to the computation time. To address the problems of fractional delay and computational burden in fast sampling systems, we propose a new method to compensate for the fractional-order sampling ***, we use a finite-impulse-response fractional delay filter based on a Lagrange interpolation polynomial to approximate the fractional portion. Moreover, we prove that high accuracy and simplicity can be ensured when the polynomial order is one. Then, we estimate the current state variable using the delayed sampling signal and control signals of past moments. Further, we obtain the current control signal according to the estimated state variable. By considering the simultaneous existence of computational and sampling delays,a full compensation strategy is proposed. Computational simulation results validate the proposed MPC algorithm with fractional-order delay compensation and demonstrate its advantages.

关键词： model predictive control fast sampling systems sampling delay fractional-order Lagrange interpolation polynomial

Vertical Vibration Isolation Using Displacement Feedback Control

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Chinese Physics Letters 1997年第10期14卷 748-751页

作者： LUO Jun zhou ze-bing Department of Physics Huazhong University of Science and TechnologyWuhan 430074

A vertical active vibration isolation system using the displacement feedback force,a method widely used in gravitational and other experiments,is reanalyzed in *** find that more effective vibration isolation could be obtained if the feedback variable is proportional to the relative displacement between the platform and the foundation other than the absolute displacement of the platform itself The physical meaning is first recognized by introducing the concept of quasi-fixed reference system,this is significant for improving the isolation ratio of an active isolation system.

关键词： system Vibration Vertical

On the Significance of Electrical Damping in Torsion Balance

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Chinese Physics Letters 1997年第8期14卷 565-568页

作者： zhou ze-bing LUO Jun Department of Physics Huazhong University of Science and TechnologyWuhan 430074

A typical electrical damping circuit for increasing the damping coefficient of a torsion balance system in high vacuum is discussed in *** analysis and numerical estimation performed with typical experimental parameters show that the signal-noise ratio can be improved by partial cooling of the electrical damping *** is significant for the torsion balance experiments.

关键词： torsion electrical estimation

Interpreting random fields through the U-Net architecture for failure mechanism and deformation predictions of geosystems

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Geoscience Frontiers 2024年第1期15卷 209-224页

作者： ze zhou Wang Jinzhang Zhang Hongwei Huang Department of Civil and Environmental Engineering National University of SingaporeSingapore 117576Singapore Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education and Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

The representation of spatial variation of soil properties in the form of random fields permits advanced probabilistic assessment of slope *** many studies,the safety margin of the system is typically characterized by the term“probability of failure(Pfailure)”.As the intensity and spatial distribution of soil properties vary in different random field realizations,the failure mechanism and deformation field of a slope can vary as *** only can the location of the failure surfaces vary,but the mode of failure also *** information is equally valuable to engineering *** this paper,two slope examples that are modified from a real case study are *** first example pertains to the stability analysis of a multi-layer-slope while the second example deals with the serviceability analysis of a multi-layer c-φ*** addition,due to the large number of simulations needed to reveal the full picture of the failure mechanism,Convolutional Neural Networks(CNNs)that adopt a U-Net architecture is proposed to offer a soft computing strategy to facilitate the *** spatial distribution of the failure surfaces,the statistics of the sliding volume,and the statistics of the deformation field are *** results also show that the proposed deep-learning model is effective in predicting the failure mechanism and deformation field of slopes in spatially variable soils;therefore encouraging probabilistic study of slopes in practical scenarios.

关键词： Deep-learning Spatial variability Slope stability Failure mechanism Sliding volume

Multi-objective optimization for 10-kW rated power dynamic wireless charging systems of electric vehicles

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Science China(Information Sciences) 2022年第10期65卷 178-195页

作者： ze zhou Zhitao LIU Hongye SU Liyan ZHANG State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and Control Zhejiang University School of Automation Wuhan University of Technology

In this paper, we propose a method to optimize the output power, efficiency, and cost of the dynamic wireless charging(DWC) system of electric vehicles by using the transmitting coil spacing as the decision variable. In a set of transmitting equipment, we adopt a structure with two transmitting networks in parallel and derive loss models. The expressions of the output power and efficiency of the DWC system are obtained by data fitting. In addition, combined with the proposed cost function, we construct a multiobjective optimization problem on output power, efficiency, and cost. Due to the complexity of the objective function, it is difficult to solve the problem by the analytic method, and thus we propose a constrained adaptive particle swarm optimization(CAPSO) algorithm with high accuracy to solve the problem. Finally,the simulation results verify the feasibility of the proposed model. The advantages of the proposed CAPSO algorithm and the optimization results under different weight combinations are presented.

关键词： dynamic wireless charging electric vehicles multi-objective optimization constrained adaptive particle swarm optimization

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Responses of a New Active Vibration Isolation System to Random Vibrations

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Chinese Physics Letters 1998年第6期15卷 429-431页

作者： zhou ze-bing LUO Jun Department of Physics Huazhong University of Science and TechnologyWuhan 430074

The responses of the test mass of the new active vibration isolation system incorporating a quasi-fixed reference system to two typical random vibrations such as Gaussian white noise and seismic noise in gravitational experiments are presented.A conclusion is obtained that the isolation performance of the new active vibration isolation system from random vibrations is better than that of the traditional one.

关键词： gravitational seismic system

Numerical investigation on the drag force of a single bubble and bubble swarm Authors

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Journal of Hydrodynamics 2020年第6期32卷 1043-1049页

作者： Ling-xin Zhang ze-cai zhou Xue-ming Shao Department of Engineering Mechanics Zhejiang UniversityHangzhou310027China

The bubble drag force correlation plays an important role in the numerical simulation accuracy of gas/liquid *** order to systematically investigate the interphase drag force of non-buoyancy driven bubbly flows,a dynamic-positioning body force(DPBF)method is developed in this *** is proved that this method has an enough computation *** this method,a series of direct numerical simulation(DNS)cases of a single bubble with low-intermediate Re(1≤Re≤200)and a bubble swarm with low Re(5.6≤Re≤45)are carried out and the bubble drag coefficients are *** on all the DNS data,the drag correlations with dimensionless parameters(Re,We for a single bubble and Re,We,gas fraction for bubble swarm)are systematically investigated and reported in this paper,which can provide a reference to the development of drag force closure model for non-buoyancy driven bubbly flows.

关键词： Gas/liquid flow bubble direct numerical simulation drag force

Composition Operators on Dirichlet Spaces and Bloch Space

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Acta Mathematica Sinica,English Series 2014年第10期30卷 1775-1784页

作者： Yuan CHENG Sanjay KUMAR ze Hua zhou Institute of Mathematics School of Science Tianjin University of Technology and Education Department of Mathematics University of Jammu Department of Mathematics Tianjin University Center for Applied Mathematics of Tianjin University

In this paper we give a Carleson measure characterization for the compact composition operators between Dirichlet type spaces. We use this characterization to show that every compact composition operator on Dirichlet ... 详细信息

关键词： Bergman spaces Bloch space Carleson measure composition operators Dirichlet typespaces

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Influence of Lithium Oxide Addition on the Sintering Behavior and Electrical Conductivity of Gadolinia Doped Ceria

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Journal of Materials Science & Technology 2011年第5期27卷 460-464页

作者： Minfang Han ze Liu Su zhou Lian Yu Union Research Center of Fuel Cell School of Chemical & Environment Engineering University of Mining & Technology(CUMTB) Beijing 100083 China

Ceria-based electrolytes have been widely researched in intermediate-temperature solid oxide fuel cell （SOFC）, which might be operated at 500-600℃. Sintering behavior with lithium oxide as sintering additive and electrical conductivity of gadolinia doped ceria （GdonCe0.902-σ, GDC10） electrolyte was studied in this paper by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical impedance spectroscopy （EIS）. As the results,, the fully dense GDC10 electrolytes are obtained at a low temperature of 800℃ with 2.5 mol% Li20 as sintering additive （called 5LiGDCS00）. During sintering process, lithium oxides adsorbed by around GDC10 surface help to sinter at 800~C and are kept at the grain boundary of GDC10 in the end. The fine grains of 100-400 nm and high electrical conductivity of 0.014 S/cm at 600~C in 5LiGDC800 were achieved, which contributed to the lower sintering temperature and enhanced grain boundary conductivity, respectively. Lithium, staying at grain boundary, reduces the depletion of oxygen vacancies in the space charge layers and increases the oxygen vacancy concentration in the grain boundary, which leads to improve the total electrical conductivity of 5LiGDC800.

关键词： Gadolinia doped ceria Sintering additive Electrical conductivity

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