scholarly journals Research of Jiles-Atherton Dynamic Model in Giant Magnetostrictive Actuator

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yongguang Liu ◽  
Xiaohui Gao ◽  
Chunxu Chen
Keyword(s):  
Mathematical Model ◽  
Dynamic Model ◽  
Control Strategies ◽  
Structural Parameters ◽  
Hysteresis Loops ◽  
Structural Dynamic ◽  
Magnetostrictive Actuator ◽  
Output Characteristics ◽  
And Control ◽  
Minor Hysteresis Loops

Due to the existence of multicoupled nonlinear factors in the giant magnetostrictive actuator (GMA), building precise mathematical model is highly important to study GMA’s characteristics and control strategies. Minor hysteresis loops near the bias magnetic field would be often applied because of its relatively good linearity. Load, friction, and disc spring stiffness seriously affect the output characteristics of the GMA in high frequency. Therefore, the current-displacement dynamic minor loops mathematical model coupling of electric-magnetic-machine is established according to Jiles-Atherton (J-A) dynamic model of hysteresis material, GMA structural dynamic equation, Ampere loop circuit law, and nonlinear piezomagnetic equation and demonstrates its correctness and effectiveness in the experiments. Finally, some laws are achieved between key structural parameters and output characteristics of GMA, which provides important theoretical foundation for structural design.

scholarly journals A Mathematical Model of COVID-19 Using Fractional Derivative: Outbreak in India with Dynamics of Transmission and Control

2020 ◽  
Author(s):  
Amjad S. Shaikh ◽  
Iqbal N. Shaikh ◽  
Kottakkaran Sooppy Nisar
Keyword(s):  
Mathematical Model ◽  
Fixed Point Theory ◽  
Control Strategies ◽  
Real Data ◽  
Control Measures ◽  
Approximation Technique ◽  
Transform Method ◽  
First Case ◽  
The Government ◽  
And Control

Since the first case of 2019 novel coronavirus disease (COVID-19) detected on Jan 30, 2020, in India, the number of cases rapidly increased to 3819 cases including 106 deaths as of 5 April 2020. Taking this into account, in the present work, we are studying a Bats-Hosts-Reservoir-People transmission fractional-order COVID-19 model for simulating the potential transmission with the thought of individual social response and control measures by the government. The real data available about infectious cases from $14^{th}$ March to $26^{th}$ March 2020 is analysed and accordingly various parameters of the model are estimated or fitted. The Picard successive approximation technique and Banach's fixed point theory have been used for verification of the existence and stability criteria of the model. Numerical computations are done utilizing the iterative Laplace transform method. In the end, we illustrate the obtained results graphically. The purpose of this study is to estimate the effectiveness of preventive measures, predicting future outbreaks and potential control strategies using the mathematical model.

Chatter stability of the constrained layer damping composite boring bar in cutting process

2019 ◽  
Vol 25 (16) ◽  
pp. 2204-2214 ◽  
Author(s):  
Zhang Yuhuan ◽  
Ren Yongsheng ◽  
Tian jishuang ◽  
Ma jingmin
Keyword(s):  
Dynamic Model ◽  
Time Domain ◽  
Structural Parameters ◽  
Frequency Domain Method ◽  
Constrained Layer Damping ◽  
Chatter Stability ◽  
Analysis Model ◽  
Structural Dynamic ◽  
Boring Bar ◽  
Cutting System

Traditional boring bars are generally made up of isotropic metallic materials and exhibit extremely poor chatter suppression ability. For enhancing the chatter stability, using anisotropic composite materials in the preparation of boring bars proves to be an effective method so as to enhance the boring bar’s natural frequency and damping. Additionally, the addition of constrained layer damping (CLD) technology on the composite boring bar can further improve the damping performance. This study aims to develop a theoretical analysis model for the prediction of the chatter stability of the CLD composite boring bar and explore the effectiveness and practicability of the CLD technology in suppressing the chatter of composite boring bar. Based on Euler–Bernoulli beam theory and the complex stiffness method of CLD, the structural dynamic model of the CLD composite boring bar was derived, and some structural parameters of the bar mainly including the ply angle of the composite material, the thicknesses of both damping layer, and constrained layer were also optimized. By combining the linear model of cutting force with a regenerative delay effect and the established dynamic model, the chatter analysis model of the CLD composite boring bar was constructed and the lobe diagram of the chatter stability of the cutting system was plotted by means of frequency domain method. The effects of the ply angle of the composite boring bar, the thicknesses of damping layer, and constrained layer on the chatter stability were examined. By performing time integral of the delay equation of motion, the time-domain response curves of the cutting system are obtained. The chatter stability prediction results based on the lobe diagram fit well with the prediction results on the basis of dynamic stiffness calculation and time-domain numerical integral results.

scholarly journals Some findings of Hybrid Sustainable Energy System for Standalone and Grid Connected Operation: Types, Storage Options, Trends for Research and Control Strategies

2019 ◽  
Vol 8 (10) ◽  
pp. 575-580
Keyword(s):  
Mathematical Model ◽  
Energy Flow ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Short Review ◽  
Energy Sources ◽  
Flow Management ◽  
Sustainable Energy System ◽  
And Control

This article presents some critical findings of various issue concerning to HSES like types, storage, trends for research and control strategies of HSES. Various interconnection techniques for HSES are presented. It has been made a short review of Mathematical model for renewable energy sources. Conclusion and result of control strategies work of HSES, Storage techniques of HSES for energy flow management is presented. Finally, it has been made a summary of the future analysis, challenges in techniques and improvements of HSES based power generation techniques for Isolated and grid connected applications

scholarly journals Analysis of COVID-19 Prevention and Control Effects Based on the SEITRD Dynamic Model and Wuhan Epidemic Statistics

2020 ◽  
Vol 17 (24) ◽  
pp. 9309
Author(s):  
Yusheng Zhang ◽  
Liang Li ◽  
Yuewen Jiang ◽  
Biqing Huang
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Control Strategies ◽  
Dynamical Behavior ◽  
Model Parameters ◽  
Time Control ◽  
Intervention Measures ◽  
Travel Restrictions ◽  
And Control ◽  
The Impact

Since December 2019, millions of people worldwide have been diagnosed with COVID-19, which has caused enormous losses. Given that there are currently no effective treatment or prevention drugs, most countries and regions mainly rely on quarantine and travel restrictions to prevent the spread of the epidemic. How to find proper prevention and treatment methods has been a hot topic of discussion. The key to the problem is to understand when these intervention measures are the best strategies for disease control and how they might affect disease dynamics. In this paper, we build a transmission dynamic model in combination with the transmission characteristics of COVID-19. We thoroughly study the dynamical behavior of the model and analyze how to determine the relevant parameters, and how the parameters influence the transmission process. Furthermore, we subsequently compare the impact of different control strategies on the epidemic, the variables include intervention time, control duration, control intensity, and other model parameters. Finally, we can find a better control method by comparing the results under different schemes and choose the proper preventive control strategy according to the actual epidemic stage and control objectives.

scholarly journals Analysis of Dynamic Characteristics and Control Strategies of a Solvent Dehydration Distillation Column in a Purified Terephthalic Acid Plant

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 125
Author(s):  
Xiuhui Huang ◽  
Jun Wang ◽  
Zeqiu Li
Keyword(s):  
Sensitivity Analysis ◽  
Dynamic Model ◽  
Control Strategy ◽  
Terephthalic Acid ◽  
Control Strategies ◽  
Plate Temperature ◽  
Dynamic Sensitivity ◽  
Purified Terephthalic Acid ◽  
And Control ◽  
Dynamic Sensitivity Analysis

In this study, a solvent dehydration column of purified terephthalic acid (PTA) plant was used as the research object. Based on a dynamic model of the solvent dehydration column, a dynamic sensitivity analysis of the key parameters was carried out using Aspen Dynamics. After the dynamic model reached stability, the reflux rate, methyl acetate concentration, and reflux temperature of the solvent dehydration column were adjusted and the changes of the key separation indexes under the corresponding disturbance were analyzed. According to the analysis results, a sensitive plate temperature controller was added to carry out the dynamic sensitivity analysis. In addition, the acetic acid (HAc) concentration of the bottom of the column was found to be unstable in the dynamic sensitivity analysis. Considering the HAc concentration controller of the column bottom, two control strategies were designed. By analyzing the dynamic response of the feed flow disturbance under different control strategies, a more suitable control strategy under different conditions was obtained. From this, a reasonable method could be derived to design the control strategy, thereby providing a theoretical basis for further real-time optimization and advanced control of solvent dehydration in a PTA plant.

Development of a Hybrid Dynamic Model and Experimental Identification of Robotic Bulldozing

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Scott G. Olsen ◽  
Gary M. Bone
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Control Strategies ◽  
Nonlinear Differential Equations ◽  
Model Framework ◽  
Modeling And Control ◽  
Low Level ◽  
Proposed Model ◽  
The Individual ◽  
And Control

The low-level modeling and control of mobile robots that interact forcibly with their environment, such as robotic excavation machinery, is a challenging problem that has not been adequately addressed in prior research. This paper investigates the low-level modeling of robotic bulldozing. The proposed model characterizes the three primary degrees-of-freedom (DOF) of the bulldozer, the blade position, the material accumulation on the blade, and the material distribution in the environment. It includes discrete operation modes contained within a hybrid dynamic model framework. The dynamics of the individual modes are represented by a set of linear and nonlinear differential equations. An instrumented scaled-down bulldozer and environment are developed to emulate the full scale operation. Model parameter estimation and validation are completed using experimental data from this system. The model is refined based on a global sensitivity analysis. The refined model is suitable for simulation and design of robotic bulldozing control strategies.

scholarly journals Modeling the COVID-19 Epidemic With Multi-Population and Control Strategies in the United States

2022 ◽  
Vol 9 ◽  
Author(s):  
Deshun Sun ◽  
Xiaojun Long ◽  
Jingxiang Liu
Keyword(s):  
United States ◽  
Mathematical Model ◽  
Control Strategies ◽  
The United States ◽  
Basic Reproductive Number ◽  
Effective Control ◽  
Model Parameters ◽  
Cumulative Number ◽  
And Control ◽  
Sensitive Parameters

As of January 19, 2021, the cumulative number of people infected with coronavirus disease-2019 (COVID-19) in the United States has reached 24,433,486, and the number is still rising. The outbreak of the COVID-19 epidemic has not only affected the development of the global economy but also seriously threatened the lives and health of human beings around the world. According to the transmission characteristics of COVID-19 in the population, this study established a theoretical differential equation mathematical model, estimated model parameters through epidemiological data, obtained accurate mathematical models, and adopted global sensitivity analysis methods to screen sensitive parameters that significantly affect the development of the epidemic. Based on the established precise mathematical model, we calculate the basic reproductive number of the epidemic, evaluate the transmission capacity of the COVID-19 epidemic, and predict the development trend of the epidemic. By analyzing the sensitivity of parameters and finding sensitive parameters, we can provide effective control strategies for epidemic prevention and control. After appropriate modifications, the model can also be used for mathematical modeling of epidemics in other countries or other infectious diseases.

scholarly journals Cost-Effective Analysis of Control Strategies to Reduce the Prevalence of Cutaneous Leishmaniasis, Based on a Mathematical Model

2018 ◽  
Vol 23 (3) ◽  
pp. 38
Author(s):  
Dibyendu Biswas ◽  
Suman Dolai ◽  
Jahangir Chowdhury ◽  
Priti Roy ◽  
Ellina Grigorieva
Keyword(s):  
Mathematical Model ◽  
Cutaneous Leishmaniasis ◽  
Control Strategies ◽  
Cost Effective ◽  
Sand Fly ◽  
Effective Control ◽  
Theoretic Approach ◽  
Epidemic Disease ◽  
And Control

Leishmaniasis is a neglected tropical vector-borne epidemic disease, and its transmission is a complex process. Zoonotic transmission to humans or animals occurs through the bites of female Phlebotominae sand flies. Here, reservoir is considered as a major source of endemic pathogen pool for disease outbreak, and the role of more than one reservoir animal becomes indispensable. To study the role of the reservoir animals on disease dynamics, a mathematical model was constructed consisting of susceptible and infected populations of humans and two types of reservoir (animal) and vector populations, respectively. Our aim is to prevent the disease by applying a control theoretic approach, when more than one type of reservoir animal exists in the region. We use drugs like sodium stibogluconate and meglumine antimoniate to control the disease for humans and spray insecticide to control the sand fly population. Similarly, drugs are applied for infected reservoir animals of Types A and B. We calculated the cost-effectiveness of all possible combinations of the intervention and control policies. One of our findings is that the most cost-effective case for Leishmania control is the spray of insecticides for infected sand fly vector. Alternate strategic cases were compared to address the critical shortcomings of single strategic cases, and a range of control strategies were estimated for effective control and economical benefit of the overall control strategy. Our findings provide the most innovative techniques available for application to the successful eradication of cutaneous leishmaniasis in the future.

Modeling and Control of a Morphing Airfoil

2003 ◽  
Author(s):  
Christopher E. Whitmer ◽  
Atul G. Kelkar ◽  
Phuc Vu ◽  
Frank R. Chavez
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Structural Model ◽  
Linear Time ◽  
Mode Shapes ◽  
Morphing Wing ◽  
Structural Dynamic ◽  
Finite Dimensional ◽  
Aeroelastic Model ◽  
And Control

This paper presents aeroelastic modelling and robust control design for a morphing airfoil concept. A finite dimensional linear time invariant aeroelastic model is developed for a multi-input multi-output morphing airfoil structure. The shape of the airfoil (NACA airfoil series 2415) is controlled by actuators distributed along the top airfoil surface that produce vertical deflections of the top surface at several locations. This results in an airfoil shape change (i.e., “morphing” of the wing), which causes changes in the aerodynamic loading on the wing. The objective is to control the deformation of the airfoil in realtime so as to achieve the desirable aerodynamic forces on the wing. The structural model is developed using the finite element approach. A finite element toolbox in Matlab, namely FEMLAB, is used to obtain eigenfrequencies and mode shapes. A finite dimensional dynamic model of the structure is obtained by the assumed modes method. A static aerodynamic model is developed with a vortex lattice method and coupled with the structural dynamic model to yield a linear aeroelastic model of the morphing wing. A robust LQG design is presented for tracking the commanded lift and roll moment. Some parametric studies are also presented for the choice of different materials. Simulation results are given to demonstrate the viability of the proposed modelling and control methodology for morphing wing concept.

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