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STATE-FEEDBACK ADAPTIVE STABILIZING control DESIGN FOR A CLASS OF HIGH-ORDER NONLINEAR SYSTEMS WITH UNKNOWN control COEFFICIENTS

第二十七届中国控制会议

作者： sun zongyao,liu yungang school of control science and engineering,shandong university,jinan 250061,P.R.China

The problem of global adaptive stabilization by state-feedback is investigated for a class of high-order nonlinear systems with uncertain control coefficients and unmeasurable zero ***,some appropriate unknown parameters are introduced to obtain the updating laws which are necessary parts in adaptive ***,by the flexible way of combing adding a power integrator with adaptive technique and the idea of changing supply functions,the requirement on the unknown control coefficients is relaxed,and a recursive design procedure is successfully developed to achieve a continuous adaptive stabilizing controller.

关键词： Adding a power integrator Unknown control coefficients Zero dynamics Adaptive stabilization

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Journal of Systems science & Complexity 2007年第3期20卷 350-361页

作者： zongyao sun yungang liu school of control science and engineering Shandong University Jinan 250061 China.

In this paper, a new approach is successfully addressed to design the state-feedback adaptive stabilizing control law for a class of high-order nonlinear systems in triangular form and with unknown and nonidentical control coefficients, whose stabilizing control has been investigated recently under the knowledge that the lower bounds of the control coefficients are exactly known. In the present paper, without any knowledge of the lower bounds of the control coefficients, based on the adaptive technique and appropriately choosing design parameters, we give the recursive design procedure of the stabilizing control law by utilizing the approach of adding a power integrator together with tuning functions. The state-feedback adaptive control law designed not only preserves the equilibrium at the origin, but also guarantees the global asymptotic stability of the closed-loop states and the uniform boundedness of all the other closed-loop signals.

关键词： Adaptive stabilizing control adding a power integrator high-order nonlinear systems,state-feedback unknown control coefficients.

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Global adaptive output-feedback tracking with prescribed performance for uncertain nonlinear systems

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science China(Information sciences) 2024年第5期67卷 150-164页

作者： Yuan WANG yungang liu school of control science and engineering Shandong University

At present, one typical control strategy for guaranteeing transient and steady-state performance is funnel control and prescribed performance control. The strategy features completely discarding the system nonlinearities, even if they are completely known and available. Such an intrinsic feature requires the controller to produce a larger control effect to eliminate the negative impact caused by the high nonlinearities, leading to a conservative controller. In this paper, we fully take advantage of known information on nonlinearities in control design, instead of completely discarding it as done in funnel control. Particularly, we leverage adaptive techniques(i.e., high-gain dynamic compensation) to deal with unknown system nonlinearities. Meanwhile, we integrate the tools of output feedback, tracking control, and the performance *** such, an adaptive output-feedback scheme is developed for global tracking with spatiotemporal performance specifications: arbitrarily given tracking accuracy and accuracy-ensured time. A simulation example supports the developed approach.

关键词： uncertain nonlinear systems output feedback prescribed performance unknown control direction dynamic high gain global tracking

A new approach to adaptive control design without overparametrization for a class of uncertain nonlinear systems

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science China(Information sciences) 2011年第7期54卷 1419-1429页

作者： ZHANG Jian & liu yungang school of control science and engineering,shandong university,jinan 250061,China school of control science and engineering Shandong University

This paper considers the globally stabilizing adaptive controller design for a class of more general uncertain high-order nonlinear systems with unknown control *** the existing literature has solved the problem,for n-dimensional systems,the existing methods need at least n + 1 dynamic updating laws for the unknown parameters to construct the stabilizing adaptive controller;that is,the dimension of the dynamic compensator is not less than n + 1,and therefore,there exists serious *** this paper,by defining some new unknown parameters which need dynamic updating,also by using adding a power integrator and related adaptive technique,the overparametrization is successfully solved and a new approach is given to design stabilizing adaptive controller based on only one parameter updating law.A simulation example is finally provided to demonstrate the validness of the proposed approach.

关键词： high-order nonlinear systems unknown control coefficients overparametrization stabilizing con- trol design adding a power integrator adaptive technique

Global practical tracking by output-feedback for nonlinear systems with unknown growth rate

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science China(Information sciences) 2011年第10期54卷 2079-2090页

作者： YAN XueHua & liu yungang school of control science and engineering,shandong university,jinan 250061,China school of control science and engineering Shandong University

This paper is devoted to the global practical tracking by output-feedback for a class of uncertain nonlinear systems with only the tracking error *** from the closely related works,the systems have unmeasured states dependent growth with unknown constant rate,and the reference signal,as well as its first order derivative,has unknown *** because of these,the tracking problem can hardly be solved by straightforwardly extending the existing *** the paper,motivated by the related stabilization results,and flexibly using the ideas of universal control and dead zone,an adaptive output-feedback controller is designed to make the tracking error prescribed arbitrarily small after a finite time while keeping all the states of the closed-loop system bounded.A numerical example demonstrates the effectiveness of the theoretical results.

关键词： uncertain nonlinear systems global practical tracking adaptive control output-feedback dynamic high-gain

H∞ control of a class of nonlinear Hamiltonian descriptor systems

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science China(Information sciences) 2010年第11期53卷 2195-2204页

作者： sun LiYing1,2 & WANG YuZhen1 1school of control science and engineering, shandong university, jinan 250061, China 2school of science, university of jinan, jinan 250022, China school of control science and engineering Shandong University school of science University of Jinan

This paper studies the stabilization and H∞ control of a class of nonlinear Hamiltonian descriptor systems. Firstly, based on the structural characteristic of the nonlinear Hamiltonian descriptor system, an equivalent nonlinear dissipative Hamiltonian differential-algebraic system is obtained by using restricted system equivalent theory. With the dissipative form, the stabilization problem is then discussed for the nonlinear Hamiltonian descriptor systems, and an H∞ controller is designed. Finally, simulations on a nonlinear circuit system are given.

关键词： nonlinear Hamiltonian descriptor systems stabilization H∞ control

L_2 DISTURBANCE ATTENUATION FOR A CLASS OF TIME-DELAY HAMILTONIAN SYSTEMS

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Journal of Systems science & Complexity 2011年第4期24卷 672-682页

作者： Weiwei sun Yuzhen WANG Renming YANG Institute of Automation Qufu Normal University Qufu 273165 China. school of control science and engineering Shandong University Jinan 250061 China.

This paper considers the problem of L2-disturbance attenuation for a class of time-delay port-controlled Hamiltonian systems. A v-dissipative inequality is established by using a proper control law and a storage function. Then based on the Razumikhin stability theorem, a sufficient condition is proposed for the asymptotically stability of the closed-loop system. Finally, the authors investigate the case that there are time-invariant uncertainties belonging to some convex bounded polytypic domain and an L2 disturbance attenuation control law is proposed. Study of illustrative example with simulation shows that the presented method in this paper works very well in the disturbance attenuation of time-delay Hamiltonian systems.

关键词： Hamiltonian systems L2 disturbance attenuation stability time-delay.

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Hydroxyl radical production by abiotic oxidation of pyrite under estuarine conditions:The effects of aging,seawater anions and illumination

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Journal of Environmental sciences 2024年第1期135卷 715-727页

作者： Ruixue liu Yinshun Dai Yucheng Feng Shiwen sun Xiaodong Zhang Chunjiang An Shan Zhao shandong Key Laboratory of Water Pollution control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityQingdao 266237China Department of Building Civil and Environmental EngineeringConcordia UniversityMontrealQC H3G 1M8Canada

Pyrite is widely distributed in estuarine sediments as an inexpensive natural Fenton-like reagent,however,the mechanism on the hydroxyl radical(HO^(·))production by pyrite under estuarine environmental conditions is still poorly *** batch experiments were performed to investigate the effects of estuarine conditions including aging(in air,in water),seawater anions(Cl^(-),Br^(-)and HCO_(3)^(-))and light on the HO^(·)production by pyrite *** one-electron transfer dominated the process from O_(2) to HO^(·)induced by oxidation of *** Fe(oxyhydr)oxide coatings on the surface of pyrite aged in air and water consumed hydrogen peroxide while mediating the electron transfer,and the combined effect of the two resulted in a suppression of HO^(·)production in the early stage of aging and a promotion of HO^(·)production in the later stage of *** of the surface oxide layers by aggressive anions was the main reason for the inhibition of HO^(·)production by Cl^(-)and Br^(-),and the generation of Cl^(·)and Br^(·)may also play a role in the scavenging of HO^(·).HCO_(3)^(-)increased the average rate of HO^(·)production through surface-CO_(2) complexes formed by adsorption on the surface of *** significant enhancement of HO^(·)production under light was attributed to the formation of photoelectrons induced by photochemical reactions on pyrite and its surface oxide *** findings provide new insights into the environmental chemical behavior of pyrite in the estuary and enrich the understanding of natural remediation of estuarine environments.

关键词： Hydroxyl radical Pyrite oxidation Aging Anions Irradiation

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Fe-doped Co_(3)O_(4) nanowire strutted 3D pinewood-derived carbon: A highly selective electrocatalyst for ammonia production via nitrate reduction

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Nano Research 2024年第4期17卷 2276-2282页

作者： Xuwei liu Chaozhen liu Xun He Zhengwei Cai Kai Dong Jun Li Xiaoya Fan Ting Xie Xiya Yang Yonglan Luo Dongdong Zheng Shengjun sun Sulaiman Alfaifi Feng Gong Xuping sun Institute of Fundamental and Frontier sciences University of Electronic Science and Technology of ChinaChengdu 610054China Key Laboratory of Energy Thermal Conversion and control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 211189China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinan 250014China Chemistry Department Frontier of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

Nitrate(NO_(3)^(-)),a nitrogen-containing pollutant,is prevalent in aqueous solutions,contributing to a range of environmental and health-related *** electrocatalytic reduction of NO_(3)^(-)holds promise as a sustainable approach to both eliminating NO_(3)^(-)and generating valuable ammonia(NH_(3)).Nevertheless,the reduction reaction of NO_(3)^(-)(NO_(3)^(-)RR),involving 8-electron transfer process,is intricate,necessitating highly efficient electrocatalysts to facilitate the conversion of NO_(3)^(-)to NH_(3).In this study,Fe-doped Co_(3)O_(4) nanowire strutted three-dimensional(3D)pinewood-derived carbon(Fe-Co_(3)O_(4)/PC)is proposed as a high-efficiency NO_(3)^(-)RR electrocatalyst for NH_(3) *** within 0.1 M NaOH containing NO_(3)^(-),Fe-Co_(3)O_(4)/PC demonstrates exceptional performance,obtain an impressively large NH_(3) yield of 0.55 mmol·h^(-1)·cm^(-2) and an exceptionally high Faradaic efficiency of 96.5%at-0.5 V,superior to its Co_(3)O_(4)/PC counterpart(0.2 mmol·h^(-1)·cm^(-2),73.3%).Furthermore,the study delves into the reaction mechanism of Fe-Co_(3)O_(4) for NO_(3)^(-)RR through theoretical calculations.

关键词： Fe-doped Co_(3)O_(4) nanowire pinewood-derived carbon electrocatalytic NO_(3)-reduction NH_(3) synthesis density functional theory