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arXiv 2020年

作者： Lu, Zhenzhen Yu, Yongguang Chen, YangQuan Ren, Guojian Xu, Conghui Wang, Shuhui Yin, Zhe Department of Mathematics Beijing Jiaotong University Beijing100044 China Mechatronics Embedded Systems and Automation Lab University of California MercedCA95343 United States

A novel coronavirus, designated as COVID-19, emerged in Wuhan, China, at the end of 2019. In this paper, a mathematical model is proposed to analyze the dynamic behavior of COVID-19. Based on inter-city networked coupling effects, a fractional-order SEIHDR system with the real-data from 23 January to 18 March, 2020 of COVID-19 is discussed. Meanwhile, hospitalized individuals and the mortality rates of three types of individuals (exposed, infected and hospitalized) are firstly taken into account in the proposed model. And infectivity of individuals during incubation is also considered in this paper. By applying least squares method and predictor-correctors scheme, the numerical solutions of the proposed system in the absence of the inter-city network and with the inter-city network are stimulated by using the real-data from 23 January to 18 − m March, 2020 where m is equal to the number of prediction days. Compared with integer-order system (α = 0), the fractional-order model without network is validated to have a better fitting of the data on Beijing, Shanghai, Wuhan, Huanggang and other cities. In contrast to the case without network, the results indicate that the inter-city network system may be not a significant case to virus spreading for China because of the lock down and quarantine measures, however, it may have an impact on cities that have not adopted city closure. Meanwhile, the proposed model better fits the data from 24 February to 31, March in Italy, and the peak number of confirmed people is also predicted by this fraction-order model. Furthermore, the existence and uniqueness of a bounded solution under the initial condition are considered in the proposed system. Afterwards, the basic reproduction number R0 is analyzed and it is found to hold a threshold: the disease-free equilibrium point is locally asymptotically stable when R0 ≤ 1, which provides a theoretical basis for whether COVID-19 will become a pandemic in the future. Copyright © 2020, The Au

关键词： Least squares approximations

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Forecast analysis of the epidemics trend of COVID-19 in the United States by a generalized fractional-order SEIR model

arXiv

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arXiv 2020年

作者： Xu, Conghui Yu, Yongguang Chen, YangQuan Lu, Zhenzhen Department of Mathematics School of Science Beijing Jiaotong University Beijing100044 Mechatronics Embedded Systems and Automation Lab University of California MercedCA95343 United States

In this paper, a generalized fractional-order SEIR model is proposed, denoted by SEIQRP model, which has a basic guiding significance for the prediction of the possi-ble outbreak of infectious diseases like COVID-19 and other insect diseases in the future. Firstly, some qualitative proper-ties of the model are analyzed. The basic reproduction num-ber R0is derived. When R00> 1, the endemic equilibrium point is also unique. Fur-thermore,some conditions are established to ensure the local asymptotic stability of disease-free and endemic equilibrium points. The trend of COVID-19 spread in the United States is predicted. Considering the influence of the individual be-havior and government mitigation measurement, a modified SEIQRP model is proposed, defined as SEIQRPD model. According to the real data of the United States, it is found that our improved model has a better prediction ability for the epidemic trend in the next two weeks. Hence, the epi-demic trend of the United States in the next two weeks is in-vestigated, and the peak of isolated cases are predicted. The modified SEIQRP model successfully capture the development process of COVID-19, which provides an important reference for understanding the trend of the outbreak. Copyright © 2020, The Authors. All rights reserved.

关键词： Forecasting

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Evacuation Control of Crowds of Pedestrians: Distributed or Decentralized? ⁎

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IFAC-PapersOnLine 2020年第5期53卷 318-323页

作者： Kecai Cao YangQuan Chen Chenglin Liu Nanjing Institute of Technology Nanjing 211167 China Mechatronics Embedded Systems and Automation Lab School of Engineering University of California Merced CA USA 95343 Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education) Institute of Automation Jiangnan University Wuxi 214122 China

Evacuation of crowds in a corridor with only one exit has been considered in this paper where distributed controllers have been constructed to regulate the crowd’s evacuation speed so that stampede tragedy can be avoided. Macroscopic model for crowds of pedestrians has been firstly derived based on inspiration of LWR (Lighthill-Whitham and Richards) model and Greenshields model from traffic system where finite volume method has been introduced to simplify the obtained PDEs into finite ODEs. Distributed evacuation controllers have been constructed based on inspiration of multi-agent system and stability analysis of obtained closed-loop system has been simplified to linear system with the delicate controllers proposed. Comparisons between distributed evacuation controllers and previous evacuation controllers have also been presented to show the advantages and disadvantages of different controllers under different initial density of crowds so that tragedy of crowd stampede can be effectively avoided with appropriate selection of different controllers.

关键词： Distributed evacuation controller Decentralized evacuation controller Stampede

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Control Performance Assessment with Fractional Lower Order Moments

Control Performance Assessment with Fractional Lower Order M...

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International Conference on Control, Decision and Information Technologies (CoDIT)

作者： Kai Liu Paweł D. Domański YangQuan Chen Mechatronics Embedded Systems & Automation (MESA) Lab University of California Merced CA USA Warsaw University of Technology Institute of Control and Computation Engineering Warsaw Poland University of California Merced CA USA

ISBN: (数字)9781728159539

ISBN: (纸本)9781728159546

Non-Gaussian statistical signal processing is be-coming increasingly significant in the current complex world. However, the variance of a non-Gaussian distribution may not exist, therefore many conventional methods will be considerably weakened, meaningless or even misleading. For example, the least-squares criterion may not be robust in the non-Gaussian environment, owing to the impulsive behaviors and outliers. In the paper, the statistical measures with fractional lower order moments (FLOM) are used instead of second-order moments to assess the control performance for non-Gaussian processes. The results show that FLOM is robust against outliers for the non-Gaussian signals. In the end, Hurst exponent fitting with FLOM and multifractal detrended fluctuation analysis (MFDFA) with FLOM are applied to the real data.

关键词： Dispersion Next generation networking Information technology Gaussian distribution Fitting Time series analysis Robustness

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Probabilistic Consensus of Multi-agent System under Joint Control of SMC and Minimum Entropy Compensation

Probabilistic Consensus of Multi-agent System under Joint Co...

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International Conference on Industrial Artificial Intelligence (IAI)

作者： Xuerou Zhang Jing Wang Jinglin Zhou Yangquan Chen Cunwu Han College of Information Science and Technology Beijing University of Chemical Technology Beijing China Key Laboratory of Beijing for Fieldbus Technology and Automation North China University of Technology Beijing China Mechatronics Embedded Systems and Automation Lab University of California Merced USA

ISBN: (数字)9781728182162

ISBN: (纸本)9781728182179

Due to the stochastic of multi-agent systems, it is difficult to achieve strict consensus. In this paper, consensus in the sense of probability is achieved by reducing the output error entropy of multi-agent system. Sliding mode controller is the core to keep the system stability and probability density function(PDF) compensator is used to reduce the chattering effect of sliding mode and compensate the random part of the system. Radial basis function neural network combined with the minimum entropy criterion is used to model the PDF compensator, and the output error entropy of the system is minimized through the training of weights, so as to optimize the control effect. Finally, the simulation results verify the effectiveness of the method.

关键词： Training Simulation Stochastic processes Probability density function Control systems Entropy Multi-agent systems

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Boundary stabilization and disturbance rejection for a time fractional order diffusion-wave equation ⁎

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IFAC-PapersOnLine 2020年第2期53卷 3695-3700页

作者： Hua-Cheng Zhou Ze-Hao Wu Bao-Zhu Guo Yangquan Chen School of Mathematics and Statistics Central South University Changsha 410075 PR China School of Mathematics and Big Data Foshan University Foshan 528000 PR China Academy of Mathematics and Systems Science Academia Sinica Beijing 100190 China Mechatronics Embedded Systems and Automation Lab University of California Merced 95343 CA USA

In this paper, we study the boundary stabilization and disturbance rejection for an unstable time fractional diffusion-wave equation involving Caputo time fractional derivative. When there is no boundary external disturbance, both state feedback control and output feedback control via boundary actuation are proposed by the classical backstepping method. It is proved that the state feedback makes the closed-loop system Mittag-Leffler stable while the output feedback makes the closed-loop system asymptotically stable. When there is boundary external disturbance, we propose a disturbance estimator which is constructed by two infinite dimensional auxiliary systems to recover the external disturbance. The resulting closed-loop system is Mittag-Leffler stable and the states of all subsystem involved are uniformly bounded. As a byproduct, we solve rigorously completely the two longtime unsolved problems raised in [Nonlinear Dynam., 38(2004), 339-354] where all the results are only verified by simulations.

关键词： Disturbance rejection fractional diffusion-wave equation Mittag-Leffler stability

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Fractional order [Proportional Integral Derivative] Controller Design with Specification Constraints: More Flat Phase Idea

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IFAC-PapersOnLine 2020年第2期53卷 3650-3656页

作者： Zhenlong Wu Yuquan Chen Jairo Viola Ying Luo YangQuan Chen Donghai Li State Key Lab of Power System Department of Energy and Power Engineering Tsinghua University Beijing 100084 China Department of Automation University of Science and Technology of China Hefei 230026 China Mechatronics Embedded Systems and Automation (MESA) Lab School of Engineering University of California Merced CA 95343 US A. School of Mechanical Science & Engineering Huazhong University of Science and Technology Wuhan 430074 China

The fractional order proportional integral derivative controller is attracting more and more attention. To design a controller with some specification constraints for the first order plus time delay (FOPTD) system, the idea of the “more flat phase” and the structure of the fractional order [proportional integral derivative] (FO[PID]) controller are proposed in this paper. Firstly, the stability region of the FO[PID] controller and the controller design with the “more flat phase” are introduced. Then the design procedure is presented by a simulation, and the pseudo code of the design procedure to obtain the parameter pairs and the achievable region is offered. The effectiveness of the proposed design method for the FO[PID] controller is verified by the experiment on the Peltier temperature control platform and the experiment results show a great potential in industrial applications.

关键词： Fractional order [proportional integral derivative] controller specification constraints first order plus time delay system more flat phase the achievable region Peltier temperature control platform

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System identification of time-delay with single fractional pole heating process considering rate limit effect

System identification of time-delay with single fractional p...

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第三十八届中国控制会议

作者： Jie Yuan YangQuan Chen Shumin Fei School of Automation Southeast University Mechatronics Embedded Systems and Automation Lab University of California Key Laboratory of Measurement and Control of CSE Ministry of Education School of Automation Southeast University

The heat transfer dynamic is extremely common in industry process. The time-delay with single fractional pole(TDSFP) model gives higher accuracy than first-order plus time-delay(FOPTD) model for the ideal heat transfer process. Actuator rate limit is a common and important phenomenon in heating process control and is becoming a stumbling block in precision process control. The actuator will get saturated for a certain duration when the identification test signal is a step function. The time duration when actuator rate is saturated can be misidentified as the delay of the process model, which misleads the controller design and generates unsatisfactory performance. This paper proposes a new model structure in identifying a TDSFP process under the step test signal and this model structure considers actuator rate limit. Parameters sensitivity is analyzed to access the effect of identification accuracy resulting from parameters estimation mismatch. An illustrative example is given to show the effectiveness of the proposed identification method and the sensitivity of system parameters.

关键词： Process control fractional-order heat transfer actuator rate limit parameter estimation parameter sensitivity

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Frequency-domain Analysis of A Modified Active Disturbance Rejection Control With Application to Superheated Steam Temperature Control

Frequency-domain Analysis of A Modified Active Disturbance R...

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International Conference on Control, automation and systems ( ICCAS)

作者： Zhenlong Wu Fan Zhang Gengjin Shi Ting He Donghai Li YangQuan Chen State Key Lab of Power Systems Tsinghua University Beijing PR China Mechatronics Embedded Systems and Automation (MESA) Lab School of Engineering University of California Merced CA USA

Superheated steam temperature (SST) systems face many control difficulties caused by unknown disturbances and high order dynamics. This is becoming more and more severe due to the rapid growing of intermittent renewable generation. To improve the tracking and disturbance rejection performance of SST systems, a modified active disturbance rejection control (ADRC) is proposed. Based on its equivalent structure, this paper develops the frequency-domain analysis of the modified ADRC to present the influence of parameters on the control performance. Then the modified ADRC based on the frequency-domain analysis is applied to the SST control to verify the superiority of the modified ADRC. Based on the results of the simulation and the field application on a power plant simulator, the modified ADRC can obtain the best tracking performance with a small overshoot and short settling time compared with other comparative controllers. Besides, the modified ADRC has the smallest fluctuation range of SST under the input disturbance and load varying conditions. The superiority of the modified ADRC ensures the satisfactory control performance and shows a great potential in industrial applications.

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Analysis of Actuator Rate Limit Effects on First-Order Plus Time-Delay systems under Fractional-Order Proportional-Integral Control

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IFAC-PapersOnLine 2018年第4期51卷 37-42页

作者： Yuan, Jie Chen, YangQuan Fei, Shumin School of Automation Southeast University Nanjing210096 China Mechatronics Embedded Systems and Automation Lab University of California MercedCA95343 United States Key Laboratory of Measurement and Control of CSE Ministry of Education School of Automation Southeast University Nanjing210096 China

Actuator rate limit deteriorates control performance, and may even lead to system instability in precision process control. In this paper, a first-order plus time-delay (FOPTD) system class with actuator rate limit is considered. The describing function (DF) of the rate limiter is derived to obtain the describing functions of the closed-loop and open-loop systems, and the onset frequency in the Nichols chart is used to analyze the rate limit effects in frequency domain. A fractional-order proportional-integral (FOPI) controller is first designed based on the flat phase constraint, crossover frequency, and phase margin specifications. Then a traditional integer-order PID (IOPID) controller is designed based on the same specifications to compare with the FOPI controller in the presence of actuator rate saturation. A careful simulation study is presented to validate all the conclusions. © 2018

关键词： Process control Actuators Controllers Delay control systems Describing functions Frequency domain analysis Proportional control systems Specifications System stability Time delay Timing circuits Two term control systems Control performance Cross over frequencies First order plus time delay First order plus time delay systems Fractional Order Proportional Integral (FOPI) Controller onset frequency Proportional integral control Rate saturation

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