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PID control of uncertain nonlinear stochastic systems with state observer

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Science China(Information Sciences) 2021年第9期64卷 139-150页

作者： Xinrong CONG cheng zhao School of Mathematics and Statistics Beijing Technology and Business University Research Center for Mathematics and Interdisciplinary Sciences Shandong University

The classical proportional-integral-derivative(PID) controller is ubiquitous in engineering systems that are typically nonlinear with various uncertainties, including random noise. However, most of the literature on PID control focused on linear deterministic systems. Thus, a theory that explains the rationale of the linear PID when dealing with nonlinear uncertain stochastic systems and a concrete design method that can provide explicit formulas for PID parameters are required. Recently, we have demonstrated that the PID controller can globally stabilize a class of second-order nonlinear uncertain stochastic systems, where the derivative of the system output is assumed to be obtainable, which is generally unrealistic in practical applications. This has motivated us to present some theoretical results on PID control with a state observer for nonlinear uncertain stochastic systems. Specifically, a five-dimensional parameter manifold can be explicitly constructed, within which the three PID parameters and two observer gain parameters can be arbitrarily selected to globally stabilize nonlinear uncertain stochastic systems, as long as some knowledge about the unknown nonlinear drift and diffusion terms is available.

关键词： PID controller system uncertainty nonlinear stochastic systems global stability state observer

On PID Control Theory for Nonaffine Uncertain Stochastic Systems

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Journal of Systems Science & Complexity 2023年第1期36卷 165-186页

作者： ZHANG Jinke zhao cheng GUO Lei Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Science University of Chinese Academy of SciencesBeijing 100049China

PID(proportional-integral-derivative)control is recognized to be the most widely and successfully employed control strategy by ***,there are limited theoretical investigations explaining the rationale why PID can work so well when dealing with nonlinear uncertain *** paper continues the previous researches towards establishing a theoretical foundation of PID control,by studying the regulation problem of PID control for nonaffine uncertain nonlinear stochastic *** be specific,a three dimensional parameter set will be constructed explicitly based on some prior knowledge on bounds of partial derivatives of both the drift and diffusion *** will be shown that the closed-loop control system will achieve exponential stability in the mean square sense under PID control,whenever the controller parameters are chosen from the constructed parameter ***,similar results can also be obtained for PD(PI)control in some special cases.A numerical example will be provided to illustrate the theoretical results.

关键词： Asymptotically regulation global stability nonaffine PID control stochastic systems uncertain structure

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Optimization for the structure of BF hearth bottom and the arrangement of thermal couples

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Journal of University of Science and Technology Beijing 2006年第6期13卷 497-503页

作者： Hongbo zhao Shusen cheng Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China

The hearth of ＂heat transfer method＂ and the ceramic cup synthetic hearth bottom of ＂heart isolation method＂ are two most popular designs for blast furnace （BF）. Although there are successful real examples, some disadvantages, for instance large heat loss and high cost, still exist for these designs. According to the theory of heat transfer, based on the calculation of temperature distribution of the hearth bottom, it is elucidated that all brick layers at the hearth bottom may not be considered as the only reason why different structures exhibited different temperature distributions although total heat resistance is the same, and then based on the effect of hot metal and cold water on different temperature distribution ranges, the concepts of ＂heat resistance＂ and ＂cooling enhancement＂ are put forth. Based on this, the disadvantages and the factors affecting temperature distribution, of the two types of hearth bottoms were illustrated. On the basis of these analyses, a novel structure for BF hearth bottom designing that can easily form ＂self-protecting＂ slag layer stably, called ＂the method of gradient brick layout that has an optimum combination of cooling enhancement and heat resistance＂ was proposed; it can not only prolong the hearth bottom longevity but also reduce the cost and heat loss. Also, the optimum arrangement of thermal couples in hearth bottom was suggested based on the previous studies on erosion prediction carried out by the author.

关键词： blast furnace hearth bottom longevity design erosion

PID controller design for second order nonlinear uncertain systems

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Science China(Information Sciences) 2017年第2期60卷 5-17页

作者： cheng zhao Lei GUO Institute of Systems Science Academy of Mathematics and Systems Science (AMSS)Chinese Academy of Sciences

Although the classical PID(proportional-integral-derivative) controller is most widely and successfully used in engineering systems which are typically nonlinear with various uncertainties, almost all the existing investigations on PID controller focus on linear systems. The aim of this paper is to present a theory on PID controller for nonlinear uncertain systems, by giving a simple and analytic design method for the PID parameters together with a mathematic proof for the global stability and asymptotic regulation of the closed-loop control systems. To be specific, we will construct a 3-dimensional manifold within which the three PID parameters can be chosen arbitrarily to globally stabilize a wide class of second order nonlinear uncertain dynamical systems, as long as some knowledge on the upper bound of the derivatives of the nonlinear uncertain function is *** will also try to make the feedback gains as small as possible by investigating the necessity of the manifold from which the PID parameters are chosen, and to establish some necessary and sufficient conditions for global stabilization of several special classes of nonlinear uncertain systems.

关键词： PID controller nonlinear uncertain systems global stability Lyapunov function asymptotic regulation

Combining SVM and CHMM classifiers for porno video recognition

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The Journal of China Universities of Posts and Telecommunications 2012年第3期19卷 100-106页

作者： zhao Zhi-cheng School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China Beijing Key Laboratory of Network System and Network Culture Beijing University of Posts and Telecommunications Beijing 100876 China

Pomo video recognition is important for Intemet content monitoring. In this paper, a novel pomo video recognition method by fusing the audio and video cues is proposed. Firstly, global color and texture features and local scale-invariant feature transform （SIFT） are extracted to train multiple support vector machine （SVM） classifiers for different erotic categories of image frames. And then, two continuous density hidden Markov models （CHMM） are built to recognize porno sounds. Finally, a fusion method based on Bayes rule is employed to combine the classification results by video and audio cues. The experimental results show that our model is better than six state-of-the-art methods.

关键词： pomo video recognition SVM keyframe CHMM audio

Multi-resonator coupled metamaterials for broadband vibration suppression

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Applied Mathematics and Mechanics(English Edition) 2021年第1期42卷 53-64页

作者： Pengcheng zhao Kai ZHANG cheng zhao Zichen DENG School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an 710072China

In this study,multi-resonator coupled metamaterials(MRCMs)with local resonators are proposed to obtain the multiple and wide band *** models of the MRCMs are established,and the boundary conditions of the unit cell are obtained with Bloch's *** effects of structural parameters,including the mass of the resonator and the spring stiffness,on the distributions of the band gaps are ***,the frequency domain responses and the time domain responses are calculated for analyzing the structural vibration characteristics and the effects of damping on structural *** results show that the frequency domain response can accurately express the distributions of the band gaps of the MRCMs,and we can increase the number and the width of the band gaps by using the MRCMs for the superior vibration suppression capability.

关键词： multi-resonator coupled metamaterial(MRCM) band gap broadband vibration suppression

Trusted Attestation Architecture on an Infrastructure-as-a-Service

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Tsinghua Science and Technology 2017年第5期22卷 469-477页

作者： Xin Jin Xingshu Chen cheng zhao Dandan zhao the College of Computer Science Sichuan University

Trusted attestation is the main obstruction preventing large-scale promotion of cloud computing. How to extend a trusted relationship from a single physical node to an Infrastructure-as-a-Service （laaS） platform is a problem that must be solved. The laaS platform provides the Virtual Machine （VM）, and the Trusted VM, equipped with a virtual Trusted Platform Module （vTPM）, is the foundation of the trusted laaS platform. We propose a multi-dimensional trusted attestation architecture that can collect and verify trusted attestation information from the computing nodes, and manage the information centrally on a cloud management platform. The architecture verifies the laaS＇s trusted attestation by apprising the VM, Hypervisor, and host Operating System＇s （OS） trusted status. The theory and the technology roadmap were introduced, and the key technologies were analyzed. The key technologies include dynamic measurement of the Hypervisor at the process level, the protection of vTPM instances, the reinforcement of Hypervisor security, and the verification of the laaS trusted attestation. A prototype was deployed to verify the feasibility of the system. The advantages of the prototype system were compared with the Open CIT （Intel Cloud attestation solution）. A performance analysis experiment was performed on computing nodes and the results show that the performance loss is within an acceptable range.

关键词： dynamic measurement trusted cloud vTPM trusted attestation

Controlled rocking pile foundation system with replaceable bar fuses for seismic resilience

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 683-696页

作者： cheng zhao Li Shuai Wang Jingquan Bridge Engineering Research Center of Southeast University School of Civil EngineeringSoutheast UniversityNanjing 210096China

Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake *** new seismic design philosophy requires bridges to maintain functionality even after severe *** this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic *** CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and *** the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its *** analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual *** contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar *** damaged fuses can be rapidly replaced to recover bridge seismic resistance following an ***,the CRPF system helps to achieve the desired postearthquake performance objectives.

关键词： seismic resilience bridges pier controlled rocking pile foundation repairable bar fuse

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