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Distributed Secondary Control of AC Microgrids With External Disturbances and Directed Communication Topologies:A Full-Order Sliding-Mode Approach

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IEEE/CAA Journal of Automatica Sinica 2021年第3期8卷 554-564页

作者： Boda Ning Qing-Long Han lei ding Center for Smart Infrastructure and Digital Construction Swinburne University of TechnologyMelbourneVIC 3122Australia School of Software and Electrical Engineering Swinburne University of TechnologyMelbourneVIC 3122Australia Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing 210023China

This paper addresses the problem of distributed secondary control for islanded AC microgrids with external *** using a full-order sliding-mode(FOSM)approach,voltage regulation and frequency restoration are achieved in finite *** voltage regulation,a distributed observer is proposed for each distributed generator(DG)to estimate a reference voltage *** from some conventional observers,the reference voltage level in this paper is accurately estimated under directed communication *** on the observer,a new nonlinear controller is designed in a backstepping manner such that an FOSM surface is reached in finite *** the surface,the voltages of DGs are regulated to the reference level in finite *** frequency restoration,a distributed controller is further proposed such that a constructed FOSM surface is reached in finite time,on which the frequencies of DGs are restored to a reference level in finite time under directed communication ***,case studies on a modified IEEE 37-bus test system are conducted to demonstrate the effectiveness,the robustness against load changes,and the plug-and-play capability of the proposed controllers.

关键词： Directed communication topologies distributed secondary control external disturbances full-order sliding-mode control microgrids

Dynamic motion of quadrupedal robots on challenging terrain:a kinodynamic optimization approach

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Frontiers of Mechanical Engineering 2024年第3期19卷 23-40页

作者： Qi LI lei ding Xin LUO Engineering Research Center of Hubei Province for Clothing Information Wuhan 430200China School of Computer Science and Artificial Intelligence Wuhan Textile UniversityWuhan 430200China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The dynamic motion of quadrupedal robots on challenging terrain generally requires elaborate spatial–temporal kinodynamic motion planning and accurate control at higher refresh rate in comparison with regular ***,conventional quadrupedal robots usually generate relatively coarse planning and employ motion replanning or reactive strategies to handle terrain *** resultant complex and computation-intensive controller may lead to nonoptimal motions or the breaking of locomotion *** this paper,a kinodynamic optimization approach is *** generate long-horizon optimal predictions of the kinematic and dynamic behavior of the quadruped robot on challenging terrain,we formulate motion planning as an optimization problem;jointly treat the foot’s locations,contact forces,and torso motions as decision variables;combine smooth motion and minimal energy consumption as the objective function;and explicitly represent feasible foothold region and friction constraints based on terrain *** track the generated motions accurately and stably,we employ a whole-body controller to compute reference position and velocity commands,which are fed forward to joint controllers of the robot’s *** verify the effectiveness of the developed approach through simulation and on a physical quadruped robot *** show that the quadruped robot can successfully traverse a 30°slope and 43% of nominal leg length high step while maintaining the rhythm of dynamic trot gait.

关键词： quadrupedal robot kinodynamic planning nonlinear optimization challenging terrain whole-body control

Improved stability of superelasticity and elastocaloric effect in Ti-Ni alloys by suppressing Lüders-like deformation under tensile load

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Journal of Materials Science & Technology 2023年第15期146卷 154-167页

作者： Pengfei Dang Jianbo Pang Yumei Zhou lei ding lei Zhang Xiangdong ding Turab Lookman Jun Sun Dezhen Xue State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China AiMaterials Research LLC Santa FeNM 87501USA

Functional stability of superelasticity is crucial for practical applications of shape memory *** is degraded by a Lüders-like deformation with elevated local stress concentration under tensile *** increasing the degree of solute supersaturation and applying appropriate thermomechanical treatments,a Ti-Ni alloy with nanocrystallinity and dispersed nanoprecipitates is *** contrast to conventional Ti-Ni alloys,the superelasticity in the target alloy is accompanied by homogeneous deformation due to the sluggish stress-induced martensitic *** alloy thus shows a fully recoverable strain of 6%under tensile stress over 1 GPa and a large adiabatic temperature decrease of 13.1 K under tensile strain of 4.5%at room ***,both superelasticity and elastocaloric effect exhibit negligible degradation in response to applied strain of 4%during *** attribute the improved functional stability to low dislocation activity resulting from the suppression of localized deformation and the combined strengthening effect of nanocrystalline structure and ***,the design of such a microstructure enabling homogeneous deformation provides a recipe for stable superelasticity and elastocaloric effect.

关键词： Ti-Ni alloys Superelasticity Elastocaloric effect Martensite band Functional stability

Role of Catalysts in the Surface Synthesis of Single-Walled Carbon Nanotubes

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Nano Research 2009年第8期2卷 593-598页

作者： Weiwei Zhou lei ding Jie Liu Department of Chemistry Duke UniversityDurhamNC 27708USA

We demonstrate the role of catalysts in the surface growth of single-walled carbon nanotubes(SWNTs)by reviewing recent progress in the surface synthesis of *** effects of catalysts on surface synthesis are studied:type of catalyst,the relationship between the size of catalyst particles and carbon feeding rates,and interactions between catalysts and *** of the role of catalysts will contribute to our ability to control the synthesis of SWNTs on various substrates and facilitate the fabrication of nanotube-based devices.

关键词： single-walled carbon nanotubes(CVD) surface growth catalysts chemical vapor deposition(CVD)

Cathode Formed by Thermal Evaporation of Ba:Al Alloy and Estimations of Barrier Height in an Organic LED

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Chinese Physics Letters 2011年第6期28卷 287-290页

作者： ding lei ZHANG Fang-Hui School of Electrical and Information Engineering Shaanxi University of Science and TechnologyXi'an 710021 Shaanxi Panel Display Engineering Center Xi'an 710021

It is demonstrated that barium and aluminum alloy synthesized by melting in a glass tube under low vacuum is applicable for organic laser emitting diodes(LEDs)as a thin film *** alloy film obtained by the thermal evaporation of pre-synthesized alloy is used in a single-boat organic LED device with the structure:indium tin oxide(ITO)/4,4'-bis[N−(1-naphthyl)-N−phenylamino]biphenyl(NPB)/tris-(8-hydroxyquinoline)aluminum(Alq3)/barium:aluminum *** experimental results show that devices with this alloy film cathode exhibit better current density-voltage-luminance characteristics than those with a conventional pure Al cathode,and more weight of barium in aluminum leads to better performance of the *** of current density versus voltage for the electron-only devices are fitted by the Richardson–Schottky emission model,indicating that the electron injection barrier has a decrease of about 0.3 eV by this alloy cathode.

关键词： alloy film Cathode

Effects of Y2O3 on the microstructure and mechanical properties ofspark plasma sintered fine-grained W-Ni-Mn alloy

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Journal of Rare Earths 2017年第11期35卷 1149-1155页

作者： Yanlin Pan lei ding Hui Li Daoping Xiang State Key Laboratory of Marine Resource Utilization in South China Sea Hainan University Haikou 570228 China Key Laboratory for Advanced Materials in Tropical Island Resources Ministry of Education Hainan University Haikou 570228 China

Fine-grained W-Ni-Mn-YOalloys were fabricated by mechanical alloying-assisted spark plasma sintering(SPS), and the effects of YOcontent on the microstructure and mechanical properties of the alloys were studied. Fine-grained 90 W-6 Ni-4 Mn-YOalloys with uniform microstructure and excellent properties were prepared by SPS at 1150 ℃. The addition of trace YOinhibited the sintering densification process and refined the W grain size. The average W grain size decreased from 5.5 μm to 2.1 μ*** fracture mode changed from W grain transgranular fracture and W-W interface fracture to W-W and W-Matrix phase interface fracture. The Rockwell hardness and bending strength of alloys initially increased and then decreased with increasing YOcontent. The optimum comprehensive mechanical properties(Rockwell hardness and bending strength) of the alloys were obtained at the same time when the mass fraction of YOwas 0.4%.

关键词： 90W-6Ni-4Mn alloys Y_2O_3 Spark plasma sintering Bending strength Fracture morphology

Fully Distributed Resilient Cooperative Control of Vehicular Platoon Systems Under DoS Attacks

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IEEE/CAA Journal of Automatica Sinica 2022年第5期9卷 937-940页

作者： lei ding Jie Li Maojiao Ye Yuan Zhao Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Automation Nanjing University of Science and TechnologyNanjing 210094China College of Information Engineering Dalian UniversityDalian 116622China IEEE

Dear Editor,This letter is concerned with distributed resilient platoon control of multiple vehicles subject to denial-of-service(DoS)*** order to accommodate the effects of DoS attacks,a fully resilient distributed control strategy is presented by designing an adaptive control gain,where any global information of communication topology is no longer ***,the conditions of time duration rates and frequency of DoS attacks on stability of vehicular platoons can be ***,a numerical simulation example is given to validate the obtained results.

关键词： DoS service designing

Distributed Nash Equilibrium Seeking for General Networked Games With Bounded Disturbances

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 376-387页

作者： Maojiao Ye Danhu Li Qing-Long Han lei ding IEEE the School of Automation Nanjing University of Science and TechnologyNanjing 210094China the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia the Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing 210023China

This paper is concerned with anti-disturbance Nash equilibrium seeking for games with partial ***,reduced-order disturbance observer-based algorithms are proposed to achieve Nash equilibrium seeking for games with firstorder and second-order players,*** the developed algorithms,the observed disturbance values are included in control signals to eliminate the influence of disturbances,based on which a gradient-like optimization method is implemented for each ***,a signum function based distributed algorithm is proposed to attenuate disturbances for games with secondorder integrator-type *** be more specific,a signum function is involved in the proposed seeking strategy to dominate disturbances,based on which the feedback of the velocity-like states and the gradients of the functions associated with players achieves stabilization of system dynamics and optimization of players'objective *** Lyapunov stability analysis,it is proven that the players'actions can approach a small region around the Nash equilibrium by utilizing disturbance observerbased strategies with appropriate control ***,exponential(asymptotic)convergence can be achieved when the signum function based control strategy(with an adaptive control gain)is *** performance of the proposed algorithms is tested by utilizing an integrated simulation platform of virtual robot experimentation platform(V-REP)and MATLAB.

关键词： Distributed networks disturbance rejection Nash equilibrium networked games

Fully Distributed Nash Equilibrium Seeking for High-Order Players With Actuator Limitations

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IEEE/CAA Journal of Automatica Sinica 2023年第6期10卷 1434-1444页

作者： Maojiao Ye Qing-Long Han lei ding Shengyuan Xu the School of Automation Nanjing University of Science and TechnologyNanjing 210094China the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia the Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing 210023China

This paper explores the problem of distributed Nash equilibrium seeking in games, where players have limited knowledge on other players' actions. In particular, the involved players are considered to be high-order integrators with their control inputs constrained within a pre-specified region. A linear transformation for players' dynamics is firstly utilized to facilitate the design of bounded control inputs incorporating multiple saturation functions. By introducing consensus protocols with adaptive and time-varying gains, the unknown actions for players are distributively estimated. Then, a fully distributed Nash equilibrium seeking strategy is exploited, showcasing its remarkable properties: (1) ensuring the boundedness of control inputs;(2) avoiding any global information/parameters;and (3) allowing the graph to be directed. Based on Lyapunov stability analysis, it is theoretically proved that the proposed distributed control strategy can lead all the players' actions to the Nash equilibrium. Finally, an illustrative example is given to validate effectiveness of the proposed method.

关键词： Actuator limitation directed networks games Nash equilibrium