检索结果-内蒙古大学图书馆

A class of anomalous diffusion epidemic models based on CTRW and distributed delay

International Journal of Biomathematics 2023年第7期16卷 249-281页

作者： Zhenzhen Lu Guojian Ren Yangquan Chen Xiangyun Meng Yongguang Yu Department of Mathematics Beijing Jiaotong University Beijing 100044 P.R.China Mechatronics Embedded Systems and Automation LabUniversity of California Merced5200 North Lake Road MercedCA 95343USA

In recent years,the epidemic model with anomalous diffusion has gained popularity in the ***,when introducing anomalous diffusion into epidemic models,they frequently lack physical explanation,in contrast to the traditional reaction-diffusion epidemic *** point of this paper is to guarantee that anomalous diffusion systems on infectious disease spreading remain physically ***,based on the continuous-time random walk(CTRW),starting from two stochastic processes of the waiting time and the step length,time-fractional space-fractional diffusion,timefractional reaction-diffusion and fractional-order diffusion can all be naturally introduced into the SIR(S:susceptible,I:infectious and R:recovered)epidemic models,*** three models mentioned above can also be applied to create SIR epidemic models with generalized distributed time *** time delay systems can also be reduced to existing models,such as the standard SIR model,the fractional infectivity model and others,within the proper ***,as an application of the above stochastic modeling method,the physical meaning of anomalous diffusion is also considered by taking the SEIR(E:exposed)epidemic model as an *** methods can be used to build other types of epidemic models,including SIVRS(V:vaccine),SIQRS(Q:quarantined)and ***,this paper describes the transmission of infectious disease in space using the real data of COVID-19.

关键词： Continuous-time random walk time-fractional space-fractional diffusion time-fractional reaction-diffusion fractional-order diffusion distributed time delay

来源：评论

学校读者我要写书评

暂无评论

Self-Optimizing Control: An Old Idea Towards Digital Twins and Parallel Intelligence (DTPI)

Self-Optimizing Control: An Old Idea Towards Digital Twins a...

引用

Digital Twins and Parallel Intelligence (DTPI), IEEE International Conference on

作者： Justus Nwoke Jairo Viola YangQuan Chen Mechatronics Embedded Systems and Automation (MESA) Lab University of California Merced CA USA

ISBN: (数字)9798350349252

ISBN: (纸本)9798350349269

The concept of self-optimizing control (SOC) can be classified as a type of learning control (LC) where a system is designed to adjust itself automatically to control an arbitrary dynamic process. Classic feedback control techniques and traditional optimal control techniques are also capable of automatically adjusting a system to a desired target but only if all the a priori information about the controlled process (plant environment) is known and can be described deterministically. Hence, learning control techniques becomes essential for systems where the a priori knowledge is unknown or incompletely known. Given this challenge, researchers through out the years and across discipline have developed and refined two possible approaches to address this challenge. One approach which is more conservative involves using the available known information to design the controller with an acceptable margin of error based on the designer’s experience. The other approach which is akin to learning control involves designing a controller which is capable of estimating the unknown information during its operation and determining an optimal control action based on the estimated information. In this work, we present the different classes of learning control which inspired the concept of self-optimizing control and the trend towards digital twin and parallel intelligence to improve system knowledge acquisition for better control.

关键词： Uncertainty Perturbation methods Process control Optimal control Stochastic processes Real-time systems Digital twins Reliability Optimization Monitoring

来源：评论

学校读者我要写书评

暂无评论

Fractional-order non-ideal isolation transformer modeling and parameter estimation for flyback power converters

引用

IFAC-PapersOnLine 2024年第12期58卷 203-208页

作者： Justus Nwoke Jairo Viola YangQuan Chen Mechatronics Embedded Systems and Automation (MESA) Lab Dept. of Mechanical Engineering University of California Merced CA 95343 USA

An accurate component modeling of power electronics converters is crucial to understanding their real performance. Thus, a fractional-order representation of energy storage components like inductors and capacitors could be helpful to refect the hidden dynamics of a power converter in voltage regulation tasks. This paper presents the fractional-order non-ideal modeling and behavioral matching of an isolation transformer used on a flyback converter. A multiphysics simulation model is built to replicate the flyback converter non-ideal dynamics. It is optimized to precisely refect the real converter response by testing various transformer configurations, including ideal, non-ideal, integer and fractional-order. The transformer parameters are adjusted using raw data from the physical power converter. Likewise, the fractional-order energy storage elements are represented using discrete circuit elements for its realization. The results obtained reveal that using a non-ideal fractional-order transformer on the flyback converter with a non-integer inductance provides the maximum ft for the power converter operation.

关键词： Flyback converter non-ideal transformer Fractional-order modeling power electronics

来源：评论

学校读者我要写书评

暂无评论

Will Fractional Order Model Based MPC Save Control Energy?

引用

IFAC-PapersOnLine 2024年第12期58卷 490-495页

作者： Shiang Cao YangQuan Chen Mechatronics Embedded Systems and Automation Lab (MESA) Dept. of Mechanical Engineering University of California Merced CA 95343 USA

In real-world situations, many complex processes exhibit fractional order dynamic characteristics. In this context, the common integer order modeling methods may not appropriately capture the physics of these processes, leading to a less satisfactory controller design. This paper conducts a comparative analysis between the First order plus time delay (FOPTD) model and the Time Delay with Single Fractional Pole (TDWFP) model. These two modeling methods are employed to characterize a one-dimensional heat propagation process and two model predictive controllers are developed based on the models. The results demonstrate a better fitting performance in both time and frequency response with the TDWFP model. Furthermore, the TDWFP model-based Model Predictive Control exhibits reduced sensitivity to the prediction horizon and requires low control input energy. This indicates the potential of using fractional order model in MPC for improved control energy efficiency in practical applications.

关键词： Fractional Order Modeling Model Predictive Control Energy Efficiency

来源：评论

学校读者我要写书评

暂无评论

Gradient-Free High-Order Accelerated Self Optimizing Control of Processes with Time Delay

Gradient-Free High-Order Accelerated Self Optimizing Control...

引用

International Conference on Industrial Artificial Intelligence (IAI)

作者： Justus Nwoke Jairo Viola YangQuan Chen Mechatronics Embedded Systems and Automation (MESA) Lab University of California Merced Merced CA USA

ISBN: (数字)9798350356618

ISBN: (纸本)9798350356625

A self-optimizing controller (SOC) adds an upper optimization layer to closed-loop systems, enhancing self-awareness and improving performance during repetitive tasks. However, most SOC optimization algorithms use only the current and previous cost function evaluations to determine the next optimal parameters (first-order optimization methods). This paper introduces a high-order self-optimizing controller (HOSOC) that accelerates the optimization algorithm's convergence by utilizing the history of optimal parameters within a sliding window. A modified version of the Globalized Constrained Nelder Mead optimization method is implemented to account for the past centroids within a memory window to compute the upcoming solution. The algorithm is tested on a general delay-aware First-Order plus Dead Time (FOPDT) system with varying lag, balanced, and delay time dynamics. Results show that the high-order SOC controller speeds up convergence and meets the desired performance specifications effectively.

关键词： Heuristic algorithms Delay effects Optimization methods Process control Cost function Delays History Closed loop systems Artificial intelligence Convergence

来源：评论

学校读者我要写书评

暂无评论

FPGA-Based Digital Twin Implementation for Mechatronic System Monitoring

FPGA-Based Digital Twin Implementation for Mechatronic Syste...

引用

International Conference on Industrial Artificial Intelligence (IAI)

作者： Justus Nwoke Marco Milanesi Jairo Viola Yang Quan Chen Mechatronics Embedded Systems and Automation (MESA) Lab University of California Merced Merced CA USA

Digital Twin is a driving technology for Industry 4.0 that enables novel capabilities like smart process control, fault detection, or remaining useful life estimation. Since a Digital Twin is an up-to-date representation of an actual physical process, building this model requires exchanging many datasets from the physical assets. Usually, it is performed on external servers within a cloud-computig architecture that communicates physical assets with the digital twin model. However, the cloud exchange introduces transmission delays and security and data privacy issues that hamper digital asset updates and create safety concerns. Hence, we propose an FPGA-based digital twin implementation where the datasets are taken directly from the physical asset running parallel to the digital asset. This setup eliminates the need for big data and cloud upload, ensuring data privacy and faster, efficient digital twin implementation and update. A case study is implemented to demonstrate embedded Digital Twin capabilities for monitoring mechatronic systems under fault events.

关键词：

来源：评论

学校读者我要写书评

暂无评论

FPGA-Based Digital Twin Implementation for Power Converter System Monitoring

FPGA-Based Digital Twin Implementation for Power Converter S...

引用

Digital Twins and Parallel Intelligence (DTPI), IEEE International Conference on

作者： Justus Nwoke Marco Milanesi Jairo Viola YangQuan Chen Mechatronics Embedded Systems and Automation (MESA) Lab University of California Merced Merced CA USA

Implementing closed-loop control requires ensuring a robust system response against undesired disturbances and random fault events. To overcome these challenges, the controllers must be able to detect and adapt the process behavior against undesired events by adjusting its parameters accordingly. Developers have utilized the concept of a digital twin—a real-time representation of the physical process—to design and update the physical controller effectively. However, traditional digital twin implementations often involve significant data exchange between the digital system and the real asset through cloud platforms, leading to data latency and privacy issues. To mitigate these concerns, we propose an FPGA-based digital twin implementation where the information is directly sourced into the Digital Twin from the physical asset, which runs in parallel with the real system. This setup eliminates the need for big data transfers and cloud uploads, ensuring enhanced data privacy and facilitating a faster and more efficient digital twin implementation and update process. To demonstrate the capabilities of embedded Digital Twin, we present a case study involving monitoring a power converter system during a sensor fault scenario.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Decentralized Model-Free Prescribed Performance Control for Interconnected systems

Decentralized Model-Free Prescribed Performance Control for ...

引用

第35届中国控制与决策会议

作者： Jinxi Zhang Tianyou Chai Yangquan Chen State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Mechatronics Embedded Systems and Automation Lab University of CaliforniaMerced

This paper is dealt with the problem of decentralized prescribed performance control(PPC) for the interconnected systems composed of feedback linearizable *** the restrictive conditions in the related studies,the interconnections need merely to be continuous in this ***,this study is focused on the model-free control design,i.e.,no prior knowledge of the system model is used for the controller,except for the most fundamentally structural *** solve the problem,a novel decentralized model-free PPC approach is *** skilful combination of the orientation function and the barrier function yields a model-free PPC,without approximation,identification,adaptation,*** adopting the dialectic by contradiction to establish the control performance,instead of the Lyapunov stability theory,it is revealed that the proposed control is inherently robust against the *** simulation results on the inverted double pendulums demonstrate the effectiveness of our approach.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Parallel self optimizing control framework for digital twin enabled smart control engineering 1

Parallel self optimizing control framework for digital twin ...

引用

1st IEEE International Conference on Digital Twins and Parallel Intelligence, DTPI 2021

作者： Viola, Jairo Chen, Yangquan University of California Merced Mechatronics Embedded Systems and Automation Lab MercedCA95343 United States

ISBN: (纸本)9781665433372

This paper presents a parallel Self Optimizing Control (SOC) framework that combines parallel intelligence, Digital Twin, and derivative-free optimization to enable smart capabilities in classic process control. The parallel SOC framework supports the interaction between the physical system and its Digital Twin via Simultaneous Perturbation Stochastic Approximation (SPSA) derivative-free optimization algorithm. The framework is tested using the Digital Twin of a thermoelectric heating system. Obtained results show that using parallel intelligence with Digital Twin and SPSA optimization method, the SOC can improve the system performance by introducing a developmental behavior on the classic process control system. © 2021 IEEE.

关键词： Process control

来源：评论

学校读者我要写书评

暂无评论

Fractional-order VRFT Reference Model and Controller Synthesis for Uniformity Temperature Control Applications

引用

IFAC-PapersOnLine 2024年第12期58卷 341-346页

作者： Juan Gabriel Araque Luis Angel Jairo Viola YangQuan Chen Dept. of Electronic Engineering Pontifical Bolivarian University Bucaramanga Colombia Mechatronics Embedded Systems and Automation (MESA) Lab Dept. of Mechanical Engineering University of California Merced CA 95343 USA

Data-driven controller synthesis methods allow finding controller parameters based only on the system input-output response. Among these methods, Virtual Reference Feedback Tuning (VRFT) is accepted thanks to its reference-model based direct parameters synthesis, including robustness and noise rejection considerations for integer and fractional-order controller design. However, for fractional-order VRFT controller synthesis, a direct solution is harder to reach involving a complex optimization problem to solve. This paper presents a recursive VRFT method for synthesizing arbitrary degree fractional-order controllers with feedforward based on a integer or fractional-order reference model. This methodology leverages existing optimization tools for fractional-order systems identification to obtain integer and fractional-order controller gains when integer and fractional-order reference models are used for the virtual error computation. The proposed method synthesizes a set of feedforward VRFT controllers implemented to control a uniform temperature control system. The results show that combining a fractional-order model or compensator improves the energy consumption of the controller and the transient temperature response in tracking and regulation tasks.

关键词： Feedforward VRFT Uniformity Temperature Control Fractional-Order VRFT Controller

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：