Fuzzy Semi-Active Control of Multi-Degree-of-Freedom Structure Using Magnetorheological Elastomers

2017 ◽  
Author(s):  
Nguyen Xuan Bao ◽  
Toshihiko Komatsuzaki ◽  
Yoshio Iwata ◽  
Haruhiko Asanuma
Keyword(s):  
Active Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Effective Control ◽  
Magnetic Flux Density ◽  
Model Parameters ◽  
Structural Vibrations ◽  
Standard Linear Solid

Magnetorheological elastomer (MRE), used in semi-active control, has recently emerged as a smart material that could potentially improve traditional systems in controlling structural vibrations. This study considers two main issues concerning the application of an MRE. The first issue is the modelling and identification of the viscoelastic property, and the second is the formulation of an effective control strategy based on the fuzzy logic system. Firstly, a nonlinear dynamic MRE model was developed to simulate the dynamic behavior of MRE. In this model, the viscoelastic force of the material as an output was calculated from displacement, frequency, and magnetic flux density as inputs. The MRE model consisted of three components including the viscoelasticity of host elastomer, magnetic field-induced property, and interfacial slippage that were modeled by analogy with a standard linear solid model (Zener model), a stiffness variable spring, and a smooth Coulomb friction, respectively. The model parameters were identified by manipulating two sets of data that were measured by changing applied electric current and harmonic excitation frequency. A good agreement was obtained between numerical and experimental results. The proposed model offers a beneficial solution to numerically investigate vibration control strategies. Secondly, a fuzzy semi-active controller was designed for seismic protection of building with an MRE-based isolator. The control strategy was designed to determine the command applied current. The proposed strategy is fully adequate to the nonlinearity of the isolator and works independently with the building structure. The efficiency of the proposed fuzzy semi-active controller was investigated numerically by MATLAB simulations, whose performance was compared with that of passive systems and a system with traditional semi-active controller. Numerical results show that the developed fuzzy semi-active controller not only mitigates the responses of both the base floor and the superstructure, but also has an ability to control structural vibrations adaptively to the different intensity ground motions.

scholarly journals A reward–punishment feedback control strategy based on energy information for wrist rehabilitation

2020 ◽  
Vol 17 (5) ◽  
pp. 172988142094065
Author(s):  
Jiajin Wang ◽  
Jiaji Zhang ◽  
Guokun Zuo ◽  
Changcheng Shi ◽  
Shuai Guo
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Adaptive Controller ◽  
Feedback Mechanism ◽  
Coefficient Of Determination ◽  
Effective Control ◽  
Rehabilitation Robot ◽  
Feedback Control Strategy ◽  
Energy Information

Based on evidence from the previous research in rehabilitation robot control strategies, we found that the common feature of the effective control strategies to promote subjects’ engagement is creating a reward–punishment feedback mechanism. This article proposes a reward–punishment feedback control strategy based on energy information. Firstly, an engagement estimated approach based on energy information is developed to evaluate subjects’ performance. Secondly, the estimated result forms a reward–punishment term, which is introduced into a standard model-based adaptive controller. This modified adaptive controller is capable of giving the reward–punishment feedback to subjects according to their engagement. Finally, several experiments are implemented using a wrist rehabilitation robot to evaluate the proposed control strategy with 10 healthy subjects who have not cardiovascular and cerebrovascular diseases. The results of these experiments show that the mean coefficient of determination ( R 2) of the data obtained by the proposed approach and the classical approach is 0.7988, which illustrate the reliability of the engagement estimated approach based on energy information. And the results also demonstrate that the proposed controller has great potential to promote patients’ engagement for wrist rehabilitation.

scholarly journals A Simplified Minimum DC-Link Voltage Control Strategy for Shunt Active Power Filters

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2407 ◽  
Author(s):  
Yu Wang ◽  
Yuewu Wang ◽  
Si-Zhe Chen ◽  
Guidong Zhang ◽  
Yun Zhang
Keyword(s):  
Power Systems ◽  
Control Strategy ◽  
Rational Design ◽  
Control Strategies ◽  
Voltage Control ◽  
Active Power ◽  
Effective Control ◽  
Voltage Control Strategy ◽  
Grid Voltage ◽  
Modulation Ratio

The active power filter (APF) is a popular electrical device to eliminate harmonics in power systems. The rational design and effective control of DC-link capacitor voltage are important for implementing APF functions. In this study, the influences from the DC-link voltage on the APF compensating current characteristic and compensation performance are analyzed, and the reason to maintain DC-link voltage at a minimum value is investigated. On this basis, a simplified minimum DC-link voltage control strategy for APF is proposed. Compared with the existing DC-link voltage control strategies, the minimum DC-link voltage value in proposed strategy is only determined by the grid voltage and modulation ratio, reducing the calculation burden and the implementation difficulty in application, avoiding the interference from external parameters on the compensation effect. Additionally, the reference DC-link voltage varies at different values according to the grid voltage and modulation ratio. A shunt APF prototype is established and the experimental results verify the correctness and effectiveness of the analysis and proposed strategy.

scholarly journals Dynamics of Salmonella transmission on a British pig grower-finisher farm: a stochastic model

2007 ◽  
Vol 136 (3) ◽  
pp. 320-333 ◽  
Author(s):  
A. A. HILL ◽  
E. L. SNARY ◽  
M. E. ARNOLD ◽  
L. ALBAN ◽  
A. J. C. COOK
Keyword(s):  
Control Strategies ◽  
Meat Consumption ◽  
Monitoring Programme ◽  
Transmission Model ◽  
Effective Control ◽  
Model Parameters ◽  
Salmonella Infections ◽  
Food Standards ◽  
Modelling Studies ◽  
Slaughter Age

SUMMARYPrevious modelling studies have estimated that between 1% and 10% of human salmonella infections are attributable to pig meat consumption. In response to this food safety threat the British pig industry have initiated a salmonella monitoring programme. It is anticipated that this programme will contribute to achieving a UK Food Standards Agency target for reducing salmonella levels in pigs at slaughter by 50% within 5 years. In order to better inform the monitoring programme, we have developed a stochastic transmission model for salmonella in a specialist grower-finisher pig herd, where data from a Danish longitudinal study have been used to estimate some of the key model parameters. The model estimates that about 17% of slaughter-age pigs will be infected with salmonella, and that of these infected pigs about 4% will be excreting the organism. In addition, the model shows that the most effective control strategies will be those that reduce between-pen transmission.

scholarly journals Estimating the Optimal Control of Zoonotic Visceral Leishmaniasis by the Use of a Mathematical Model

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Laila Massad Ribas ◽  
Vera Lucia Zaher ◽  
Helio Junji Shimozako ◽  
Eduardo Massad
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Visceral Leishmaniasis ◽  
Vector Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Effective Control ◽  
Alternative Control ◽  
Alternative Strategies ◽  
Zoonotic Visceral Leishmaniasis

We argue that the strategy of culling infected dogs is not the most efficient way to control zoonotic visceral leishmaniasis (ZVL) and that, in the presence of alternative control strategies with better potential results, official programs of compulsory culling adopted by some countries are inefficient and unethical. We base our arguments on a mathematical model for the study of control strategies against ZVL, which allows the comparison of the efficacies of 5, alternative strategies. We demonstrate that the culling program, previously questioned on both theoretical and practical grounds is the less effective control strategy. In addition, we show that vector control and the use of insecticide-impregnated dog collars are, by far, more efficient at reducing the prevalence of ZVL in humans.

Discussion on the Garbage Disposal Control System Based on DCS

2012 ◽  
Vol 229-231 ◽  
pp. 2188-2191
Author(s):  
Mei Xu
Keyword(s):  
Complex System ◽  
Control System ◽  
Control Problem ◽  
Intelligent Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Effective Control ◽  
Control Methods ◽  
Paper Briefly ◽  
Garbage Disposal

The garbage disposal system is not a very large system,but it is a complex system..You need to take different control strategies according to different control objects, belonging to the control problem of the complexity of the uncertainty of the object (or process). Conventional control methods (such as PID, etc.) is difficult to implement effective control of such object.It is necessary to explore more effective control strategy. The paper briefly discusses the problem of intelligent control of the garbage disposal systems based on DCS.

Roll Damping and Anti-Capsizing System for Ships Using Fuzzy-Extension Control Strategy

2011 ◽  
Vol 84-85 ◽  
pp. 144-154
Author(s):  
Ming Hui Wang ◽  
Yong Quan Yu ◽  
Bi Zeng
Keyword(s):  
Control Strategy ◽  
Effective Control ◽  
Model Parameters ◽  
Gradual Change ◽  
Classical Domain ◽  
Roll Damping ◽  
Loss Of Life ◽  
Extension Domain ◽  
Ship Roll ◽  
Fuzzy Control Strategy

Rolling is an undesirable motion for ships. Large amplitude rolling can easily lead to capsize which will cause the loss of life and property. This paper proposes a fuzzy-extension control strategy for ship roll damping and anti-capsizing system. Fuzzy control strategy is studied in the classical domain for rudder roll stabilization to solve uncertainties in quantitative change and gradual change resulting from the change of ship model parameters so as to improve control performance. Moreover, the real-time tuning algorithm is presented to tune the fuzzy rules. Extension control strategy is studied in extension domain to solve the uncertainties in non-gradual change arising from the wave so as to extend anti-capsizing control sphere. Every control strategy can realize effective control within the scope of control.The two intelligence control methods are combined to increase the level of intelligence of system. This paper carries out the simulation under various situations such as different navigation speed, sea conditions, encounter angle and ship parameter perturbation, to test the roll reduction and robustness of the roll controller designed.

Integrated Control of Rotating Stall and Surge in High-Speed Multi-Stage Compression Systems

1997 ◽  
Author(s):  
K. M. Eveker ◽  
D. L. Gysling ◽  
C. N. Nett ◽  
O. P. Sharma
Keyword(s):  
Active Control ◽  
Control Strategy ◽  
High Speed ◽  
Control Strategies ◽  
Integrated Control ◽  
Axial Flow ◽  
Rotating Stall ◽  
Low Flow ◽  
Multi Stage ◽  
Simultaneous Control

Aeroengines operate in regimes for which both rotating stall and surge impose low flow operability limits. Thus, active control strategies designed to enhance operability of aeroengines must address both rotating stall and surge as well as their interaction. In this paper, a previously developed nonlinear control strategy that achieves simultaneous active control of rotating stall and surge is applied to a high-speed 3-stage axial flow compression system with operating parameters representative of modern aeroengines. The controller is experimentally validated for 2 compressor builds and its robustness to radial distortion assessed. For actuation, the control strategy utilizes an annulus-averaged bleed valve with bandwidth on the order of the rotor frequency. For sensing, measurements of the circumferential asymmetry and annulus-averaged unsteadiness of the flow through the compressor are used. Experimental validation of simultaneous control of rotating stall and surge in a high-speed environment with minimal sensing and actuation requirements is viewed as another important step towards applying active control to enhance operability of compression systems in modem aeroengines.

scholarly journals Comparison between two types of control strategies for the coronavirus disease 2019 pandemic

2020 ◽  
Vol 14 (07) ◽  
pp. 696-698
Author(s):  
Xiaoyan Zhang ◽  
Yuxuan Wang
Keyword(s):  
Comparative Analysis ◽  
Severe Acute Respiratory Syndrome ◽  
Control Strategy ◽  
Prevention And Control ◽  
Control Strategies ◽  
Influenza Pandemic ◽  
Control Measures ◽  
Effective Control ◽  
Epidemic Control ◽  
And Control

Different countries have employed various strategies for controlling the coronavirus disease (COVID-19) pandemic because there is no consensus regarding effective control measures in the literature. Epidemic control strategies can be classified into two types based on their characteristics. The first type is the “severe acute respiratory syndrome (SARS)-like epidemic control strategy,” i.e., containment. The second type is the “influenza pandemic-like epidemic control strategy” (flu pandemic-like strategy), i.e., mitigation. This paper presents a comparative analysis on the prevention and control strategies for COVID-19 in different countries to provide a reference to control the further spread of the pandemic.

Influence of closed loop control on microbial diversity in a nitrification process

2006 ◽  
Vol 53 (4-5) ◽  
pp. 85-93 ◽  
Author(s):  
D. Bougard ◽  
N. Bernet ◽  
P. Dabert ◽  
J.P. Delgenes ◽  
J.P. Steyer
Keyword(s):  
Microbial Diversity ◽  
Active Control ◽  
Control Strategy ◽  
Closed Loop ◽  
Control Strategies ◽  
Closed Loop Control ◽  
Loop Control ◽  
Nitrification Process ◽  
Term Evaluation

This paper compares two control strategies for a nitrification process. The objective is to achieve partial nitrification and thus to accumulate nitrite instead of nitrate. To this end, change in temperature setpoint and active control of oxygen and ammonia concentrations are evaluated in the long term. Evaluation is made on the control performances that are obtained, but also – and more importantly – on the microbial diversity. In particular, it is shown that the combined oxygen and ammonia control strategy is more appropriate since shift in the temperature setpoint strongly affects the composition of the microbial ecosystem present in the reactor whereas active control of oxygen and ammonia does not.

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.

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