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Uncoupled PID Control of Coupled Multi-Agent Nonlinear Uncertain Systems

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Journal of Systems Science & Complexity 2018年第1期31卷 4-21页

作者： YUAN Shuo zhao cheng GUO Lei LSC Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China. School of Mathematical Sciences University of Chinese Academy of Sciences Beijing 100049 China LSC Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

In this paper, PID（proportional-integral-derivative） controllers will be designed to solve the tracking problem for a class of coupled multi-agent systems, where each agent is described by a second-order high-dimensional nonlinear uncertain dynamical system, which only has access to its own tracking error information and does not need to communicate with others. This paper will show that a 3-dimensional manifold can be constructed based on the information about the Lipschitz constants of the system nonlinear dynamics, such that whenever the three parameters of each PID controller are chosen from the manifold, the whole multi-agent system can be stabilized globally and the tracking error of each agent approaches to zero asymptotically. For a class of coupled first-order multi-agent nonlinear uncertain systems, a PI controller will be designed to stabilize the whole system.

关键词： Coupled multi-agent system global stability Lipschitz condition nonlinear uncertain dynamics PID controller

Quantificational indexes for design and evaluation of copper staves for blast furnaces

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Journal of University of Science and Technology Beijing 2008年第1期15卷 10-16页

作者： Liang Qian Susen cheng Hongbo zhao School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Continuous Casting Technology Engineering Co. Ltd. MCC Group Beijing 100081 China

The quantificational and normative design is the precondition of improving the design of copper staves for blast furnaces. Based on a 3-dimensional temperature field calculation model, from the view point of heat transfer and long campaigns note with the core of forming accretion, the forming-accretion-ability （FAA） and the rib hot surface maximum temperature difference （ATmax） as quantificational indexes to direct and evaluate the design of copper staves for blast furnaces were presented. The application of the two indexes in design essentially embodies the new long campaigns in the stage of design. With the application of the two indexes, good results can be obtained. Firstly, it was suggested that the rib height of a copper stave can be reduced to 15 mm, which is a new method and theory for the reduction of copper staves. Secondly, the influence of insert on FAA and ATmax, is decided by the volume of insert. According to this, the principle of design for the hot surface geometry of copper staves was put forward that the ratio of the rib hot surface to the copper stave hot surface （abbreviated as the ratio of rib to stave） must be maintained in the range of 45% to 55%; for the present copper stave with a 35-40 mm thick rib, the ratio of rib to stave in the range of 50% to 55% can optimize the design of copper staves; for the copper stave with a smaller rib thickness, for example 15 ram, the ratio of rib to stave in the range of 45% to 50% can optimize the design of copper staves. It can be summarized that the thicker the rib thickness, the larger is the ratio of rib to stave. 2008 University of Science and Technology Beijing. All rights reserved.

关键词： blast furnace (BF) copper stave quantificational index forming-accretion-ability

High-throughput experimental tools for the materials genome initiative

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Chinese Science Bulletin 2014年第15期59卷 1652-1661页

作者： Ji-cheng zhao Department of Materials Science and Engineering The Ohio State University State Key Laboratory of Powder Metallurgy Central South University

The materials innovation infrastructure in the materials genome initiative(MGI)consists of three major components:computational tools,experimental tools,and digital *** article will review experimental tools for high-throughput,high spatial resolution measurements of several materials properties such as elastic modulus,thermal conductivity,specific heat capacity,and thermal *** of these tools on compositionvarying samples such as diffusion multiples can be used to quickly and efficiently obtain composition–phase–structure–property relationships for materials property database *** can also be used in conjunction with theoretical modeling to find and explain unusual effects to improve the predictability of *** micron scale resolution experimental tools are in *** high-throughput tools will be an essential part of MGI.

关键词：计算工具材料性能基因组计划高通量实验高空间分辨率属性数据库组成部分

Discussion on the extensions of the entransy theory

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Science China(Technological Sciences) 2017年第3期60卷 363-373页

作者： cheng XueTao zhao JianMing LIANG XinGang Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of Aerospace Tsinghua University Beijing 100084 China The Administrative Committee of the Modern Industrial Park New District of Zhengpu Port Maanshan 238261 China PBC School of Finance Tsinghua University Beijing 100084 China

In this paper,the preconditions forthe extensions of the entransy theory are summarized and *** the physical meaning of

关键词： entransy potential energy similarity extension microeconomics

A formal structure for symbolic reachability analysis of rectangular hybrid systems

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Science China(Technological Sciences) 2016年第2期59卷 347-356页

作者： ZHANG HaiBin zhao cheng LI Rong School of Cyber Engineering Xidian University

For symbolic reachability analysis of rectangular hybrid systems, the basic issue is finding a formal structure to represent and manipulate its infinite state spaces. Firstly, this structure must be closed to the reachability operation which means that reachable states from states expressed by this structure can be presented by it too. Secondly, the operation of finding reachable states with this structure should take as less computation as possible. To this end, a constraint system called rectangular zone is formalized, which is a conjunction of fixed amount of inequalities that compare fixed types of linear expressions with two variables to rational numbers. It is proved that the rectangular zone is closed to those reachability operations-intersection, elapsing of time and edge transition. Since the number of inequalities and the linear expression of each inequality is fixed in rectangular zones, so to obtain reachable rectangular zones, it just needs to change the rational numbers to which these linear expressions need to compare. To represent rectangular zones and unions of rectangular zones, a data structure called three dimensional constraint matrix(TDCM) and a BDD-like structure rectangular hybrid diagram(RHD) are introduced.

关键词： rectangular hybrid systems symbolic methods reachability analysis

Experimental and numerical investigation of failure mode in geometrically imperfect DP590 steel

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Science China(Technological Sciences) 2015年第3期58卷 476-484页

作者： ZHUANG XinCun XU cheng zhao Zhen Institute of Forming Technology & Equipment School of Materials Science and Engineering Shanghai Jiaotong University

Various microstructure-level finite element models were generated according to the real microstructure of DP590 steel to capture the mechanical behavior and fracture *** failure mode of the dual-phase(DP)steels,mainly resulting from microstructure-level inhomogeneity and initial geometrical imperfection,was predicted using the plastic strain localization *** addition,dog-bone-type tensile test specimens with different edge qualities were prepared and the deformation processes were recorded using a digital image correlation *** the steel exhibited no initial geometrical imperfection,void initiation was triggered by decohesion between martensite and ferrite which was predicted based on the severe strain concentration,or tensile stress in areas where stress triaxiality and strain values were *** failure was caused by shear localization in the ***,the initial geometrical imperfections severely affected the overall ductility and failure mode of the *** initial geometrical imperfections were deeply ingrained,an incipient crack began at the site of initial geometrical imperfection,and then caused progressive damage throughout the microstructure,from the area of shear localization to the final ***,the depth of the geometrical imperfection was the critical factor in determining whether internal decohesion or a local crack plays a dominant role.

关键词： representative volume element dual-phase(DP) steel geometrical imperfection failure mode

Main factors influencing the expulsion of oil derived from coal

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Chinese Science Bulletin 1997年第22期42卷 1905-1908页

作者： zhao, CY cheng, KM China Natl Petr Corp Res Inst Petr Explorat & Dev Beijing 100083 Peoples R China

THE expulsion of hydrocarbons from coal is controlled by two main factors. The first is theproperties inherited from coal itself and contains two implications. One is original potential ofhydrocarbon generation from c... 详细信息

关键词： oil derived from coal expulsion pore surface chemistry.

Facile measurement of single-crystal elastic constants from polycrystalline samples

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npj Computational Materials 2017年第1期3卷 325-332页

作者： Xinpeng Du Ji-cheng zhao Department of Materials Science and Engineering The Ohio State UniversityColumbusOHUSA

Elastic constants are among the most fundamental properties of *** of microstructural evolution and constitutive/micro-mechanistic modeling of materials properties require elastic constants that are predominately measured from single crystals that are labor intensive to grow.A facile technique is developed to measure elastic constants from polycrystalline *** technique is based upon measurements of the surface acoustic wave velocities with the help of a polydimethylsiloxane film grating that is placed on a polished surface of a polycrystalline sample to confine surface acoustic waves that are induced by a femtosecond laser and measured using pump-probe time-domain *** backscatter diffraction is employed to measure the crystallographic orientation along which the surface acoustic wave propagates in each grain(perpendicular to the polydimethylsiloxane grating).Such measurements are performed on several grains.A robust mathematical solution was developed to compute the surface acoustic wave velocity along any crystallographic orientation of any crystal structure with given elastic constants and *** inputting various starting values of elastic constants to compute the surface acoustic wave velocities to match experimental measurements in several distinct crystallographic orientations using an optimization algorithm,accurate elastic constant values have been obtained from seven polycrystalline metal samples to be within 6.8% of single-crystal *** new technique can help change the current scenario that experimentally measured elastic constants are available for only about 1% of the estimated 160,000 distinct solid compounds,not to mention the significant need for elastic constants of various solid solution compositions that are the base of structural materials.

关键词： materials. density. constants

Potential energy surface and formation of superheavy nuclei with the Skyrme energy-density functional

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Communications in Theoretical Physics 2022年第5期74卷 97-105页

作者： cheng Peng zhao-Qing Feng School of Physics and Optoelectronics South China University of TechnologyGangzhou 510640 China

With the Skyrme energy-density functional theory,the nucleus–nucleus potential is calculated and the potential energy surface is obtained with different effective forces for accurately estimating the formation cross sections of superheavy nuclei in massive fusion *** width and height of the potential pocket are influenced by the Skyrme effective forces SkM,SkM^(*),SkP,SIII,Ska,and SLy4,which correspond to the different equations of state for the isospin symmetry nuclear *** is found that the nucleus–nucleus potential is associated with the collision orientation and Skyrme forces.A more repulsive nuclear potential is pronounced with increasing the incompressible modulus of nuclear matter,which hinders the formation of superheavy *** available data in the fusion-evaporation reaction of ^(48)Ca+^(238)U are nicely reproduced with the SkM^(*) parameter by implementing the potential into the dinuclear system model.

关键词： Skyrme force nucleus-nucleus potential energy density functional DNS model