Optimal Design of a Stable Fuzzy Controller for Beyond Pull-In Stabilization of Electrostatically Actuated Circular Microplates

The current paper aims to provide an optimal stable fuzzy controller to extend the travel range of a pair of flexible electrostatically actuated circular microplates beyond their pull-in limit. The single mode assumption is utilized to derive the equation of motion of the system based on a Lagrangian approach. The static behavior of the system is studied using the proposed model, and the utilized assumption and the relevant results are closely verified by nonlinear finite element simulations. The open-loop dynamic analysis is also performed to derive the linguistic rules governing the voltage-deflection behavior of the system. The mentioned rules are then employed for designing a fuzzy controller, which controls the deflection of the microplates. The controller is then optimized to provide better response specifications. The performance of the optimal fuzzy controller is compared with that of the optimal proportional–integral–derivative (PID) controller and obvious superiorities in terms of noise suppression and stability enhancement are observed. To guarantee the stability of the closed-loop system, another higher level controller is designed to oversee the behavior of the fuzzy controller. Simulation results reveal that the superintended fuzzy controller can prevent instability, while fairly extending the travel range of system and providing it with a better transient response. The suggested design approach proposed in this paper may be used to improve the performance of many nano/micro devices and nano/micro positioning systems.

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A Two-Level Adaptive Fuzzy Control Algorithm for Beyond Pull-In Stabilization of Electrostatically Actuated Microplates

Volume 2: Mechatronics; Mechatronics and Controls in Advanced Manufacturing; Modeling and Control of Automotive Systems and Combustion Engines; Modeling and Validation; Motion and Vibration Control Applications; Multi-Agent and Networked Systems; Path Planning and Motion Control; Robot Manipulators; Sensors and Actuators; Tracking Control Systems; Uncertain Systems and Robustness; Unmanned, Ground and Surface Robotics; Vehicle Dynamic Controls; Vehicle Dynamics and Traffic Control ◽

10.1115/dscc2016-9841 ◽

2016 ◽

Cited By ~ 1

Author(s):

Moeen Radgolchin ◽

Hamid Moeenfard ◽

Amir H. Ghasemi

Keyword(s):

Fuzzy Controller ◽

Adaptive Fuzzy Control ◽

Single Mode ◽

Lagrange Equations ◽

Dynamic Simulations ◽

Positioning Systems ◽

Electrostatically Actuated ◽

Performance Specifications ◽

Control Objective ◽

Fuzzy Control Algorithm

The objective of this paper is to present an adaptive multi-level fuzzy controller to stabilize the deflection of an electrostatically actuated microplate beyond its pull-in range. Using a single mode approximation along with utilizing the Lagrange equations, the dynamic behavior of the microplate is described in modal space by an ordinary differential equation. By different static and dynamic simulations, the system and the dependence of the deflection to the input applied voltage is identified linguistically. Then, based on the linguistic description of the system, a fuzzy controller is designed to stabilize the microplate at the desired deflections. To improve the performance specifications of the closed-loop system, another fuzzy controller at a higher level is designed to adjust the parameters of the main controller in real time. The simulation results reveal that by using the proposed single level and adaptive two level controllers, the control objective is met effectively with good performance specifications. It is also observed that adding a supervisory level to the main controller can reduce the overshoot and the settling time in beyond pull-in stabilization of electrostatically actuated microplates. The qualitative knowledge resulting from this research can be generalized and used for development of efficient controllers for N/MEMS actuators and electrostatically actuated nano/micro positioning systems.

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Stability and Bifurcation Analysis of an Asymmetrically Electrostatically Actuated Microbeam

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4028537 ◽

2015 ◽

Vol 10 (2) ◽

Cited By ~ 9

Author(s):

Hadi Madinei ◽

Ghader Rezazadeh ◽

Saber Azizi

Keyword(s):

Applied Voltage ◽

Equilibrium Points ◽

Pitchfork Bifurcation ◽

Spring Model ◽

Electrostatically Actuated ◽

Proposed Model ◽

Mass Spring Model ◽

The Stability ◽

Mass Spring ◽

Two Degree Of Freedom

This paper deals with the study of bifurcational behavior of a capacitive microbeam actuated by asymmetrically located electrodes in the upper and lower sides of the microbeam. A distributed and a modified two degree of freedom (DOF) mass–spring model have been implemented for the analysis of the microbeam behavior. Fixed or equilibrium points of the microbeam have been obtained and have been shown that with variation of the applied voltage as a control parameter the number of equilibrium points is changed. The stability of the fixed points has been investigated by Jacobian matrix of system in the two DOF mass–spring model. Pull-in or critical values of the applied voltage leading to qualitative changes in the microbeam behavior have been obtained and has been shown that the proposed model has a tendency to a static instability by undergoing a pitchfork bifurcation whereas classic capacitive microbeams cease to have stability by undergoing to a saddle node bifurcation.

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Deflection Control of Electrostatically Actuated Micro Cantilevers via Fuzzy Controller

Volume 1: Advances in Control Design Methods, Nonlinear and Optimal Control, Robotics, and Wind Energy Systems; Aerospace Applications; Assistive and Rehabilitation Robotics; Assistive Robotics; Battery and Oil and Gas Systems; Bioengineering Applications; Biomedical and Neural Systems Modeling, Diagnostics and Healthcare; Control and Monitoring of Vibratory Systems; Diagnostics and Detection; Energy Harvesting; Estimation and Identification; Fuel Cells/Energy Storage; Intelligent Transportation ◽

10.1115/dscc2016-9838 ◽

2016 ◽

Cited By ~ 1

Author(s):

Mohammad Khadembashi ◽

Hamid Moeenfard ◽

Amir H. Ghasemi

Keyword(s):

Passive Control ◽

Fuzzy Controller ◽

Open Loop ◽

Beam Deflection ◽

The Novel ◽

Lagrange Equations ◽

Controlled System ◽

Single Level ◽

Electrostatically Actuated ◽

Micro Structures

The objective of this paper is to develop a novel two-level supervised fuzzy controller to stabilize the response of electrostatically actuated microbeams beyond their pull-in range. To this end, Lagrange equations are utilized to derive the differential equations governing the dynamic behavior of the system. To investigate the possibility of using a passive control strategy, the static behavior of the system is studied in detail. Through some open loop simulations, the qualitative and quantitative dependence of the beam deflection to the applied voltage and system parameters are studied. Based on the understanding obtained from these studies, a single level fuzzy controller is designed to control the response of the microstructure. In order to enhance the performance of the closed-loop system, another higher level supervisory fuzzy controller is designed to tune the maximum allowable voltage the lower level controller can apply. Simulation results reveal that both single level and multi-level fuzzy controllers can extend the travel range of the microbeams beyond its pull-in range. However the rise time, overshoot and settling time in the multilevel controlled system is far better than that of a simple single level fuzzy controller. The novel controller presented in this paper can be applied in most intrinsically nonlinear nano/micro structures to help them to have more efficient regulations and command tracking maneuvers.

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Effect of fiber and solenoid variation parameters on the elements of a corrector PID for electromagnetic fiber squeezer based polarization controller

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v10i3.pp2441-2451 ◽

2020 ◽

Vol 10 (3) ◽

pp. 2441 ◽

Cited By ~ 2

Author(s):

Abdallah Zahidi ◽

Amrane Said ◽

Nawfel Azami ◽

Naoual Nasser

Keyword(s):

Detection System ◽

Light Output ◽

Single Mode ◽

Single Mode Fiber ◽

Open Loop ◽

Polarization Controller ◽

Heterodyne Detection ◽

System Parameters ◽

Stability Performance ◽

The Stability

Controlling the polarization of the light output from single-mode fiber systems is very important for connecting it to polarization-dependent integrated optical circuits, while applications using a heterodyne detection system. Polarization controller using fiber squeezer is attractive for a low-loss, low-penalty coherent optical fiber trunk system. However, for polarization controllers using electromagnetic fiber squeezer, the stability problem due to the saturation of their magnetic circuit must be studied. In fact, in their conventional configuration, open-loop stability affects performance and limits applications. First at all, this effect has been analyzed and a feedback circuit with correctors has been proposed to improve stability performance. Then a simulation study is proposed to examine the influence of the system parameters on the corrector constants. The results of the simulation show that if the system parameters change the constants Kp, Ki and Kd of the PID corrector must be adjusted to keep an optimized dynamic response.

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Study of the stability of fuzzy controllers by an estimation of the attraction regions: A Vector Norm approach

Mathematical Problems in Engineering ◽

10.1080/10241230215288 ◽

2002 ◽

Vol 8 (3) ◽

pp. 221-231 ◽

Cited By ~ 2

Author(s):

J.-Y. Dieulot ◽

A. El Kamel ◽

P. Borne

Keyword(s):

Fuzzy Controller ◽

Domain Of Attraction ◽

Constant Term ◽

Open Loop ◽

Region Of Attraction ◽

Open Loop System ◽

Controlled System ◽

Disjoint Sets ◽

The Stability ◽

Vector Norms

A fuzzy controller with singleton defuzzification can be considered as the association of a regionwise constant term and of a regionwise non linear term, the latter being bounded by a linear controller. Based on the regionwise structure of fuzzy controller, the state space is partitioned into a series of disjoint sets. The fuzzy controller parameters are tuned in order to ensure that theith set is included into the domain of attraction of the preceding sets of the series. If the first set of the series is included into the region of attraction of the equilibrium point, the overall fuzzy controlled system is stable. The attractors are estimated with the help of the comparison principle, using Vector Norms, which ensures the robustness with respect to uncertainties and perturbations of the open loop system.

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Development of a multi-level adaptive fuzzy controller for beyond pull-in stabilization of electrostatically actuated microplates

Journal of Vibration and Control ◽

10.1177/1077546316653040 ◽

2016 ◽

Vol 24 (5) ◽

pp. 860-878 ◽

Cited By ~ 20

Author(s):

Moeen Radgolchin ◽

Hamid Moeenfard

Keyword(s):

Closed Loop ◽

Fuzzy Controller ◽

Loop System ◽

Mode Shapes ◽

Closed Loop System ◽

Positioning Systems ◽

Electrostatically Actuated ◽

System A ◽

Performance Specifications ◽

Multi Level

The objective of this paper is to present a supervised multi-level fuzzy controller to control the deflection of an electrostatically actuated microplate within and beyond its pull-in range. The mode shapes of the microplate are derived using Extended Kantorovich Method (EKM) which are shown to be in great agreement with finite element results. Using open loop simulations, it is shown that the first mode shape is effectively the dominant one. Then by utilizing a single mode approximation along with employing the Lagrange equation, the dynamic behavior of the microplate is described in modal space by an ordinary differential equation. By static and dynamic simulations, dependence of the plate deflection on the applied voltage is identified linguistically. Then based on the linguistic description of the system, a fuzzy controller is designed to stabilize the microplate at desired deflections. To improve the performance specifications of the closed-loop system, another fuzzy controller at a higher level is proposed to adjust the parameters of the main controller in real time. To guarantee the stability of the closed-loop system, a non-fuzzy supervisory unit is attached to the control architecture. The simulations results reveal that by using the presented single level and supervised adaptive controllers, the control objective is met effectively with good performance specifications. It is also observed that adding a second level and a supervisory unit to the main controller can reduce the overshoot and the settling time for within and beyond pull-in stabilization of electrostatically actuated microplates in following the step commands. Excellent performance of the system in the presence of the proposed controller is further demonstrated using multiple step and also sinusoidal commands. The qualitative knowledge resulting from this research can be generalized and used for development of efficient controllers for N/MEMS actuators and electrostatically actuated nano/micro positioning systems.

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Dual Two-Level Voltage Source Inverter Virtual Inertia Emulation: A Comparative Study

Energies ◽

10.3390/en14041160 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1160

Author(s):

Mohammad Ali Dashtaki ◽

Hamed Nafisi ◽

Amir Khorsandi ◽

Mojgan Hojabri ◽

Edris Pouresmaeil

Keyword(s):

Harmonic Distortion ◽

Synchronous Generator ◽

Voltage Source ◽

Small Signal ◽

Voltage Source Inverter ◽

Nonlinear Loads ◽

Virtual Inertia ◽

The Stability ◽

Stability Enhancement ◽

Oscillation Damping

In this paper, the virtual synchronous generator (VSG) concept is utilized in the controller of the grid-connected dual two-level voltage source inverter (DTL VSI). First, the topology of the VSG and the DTL VSI are presented. Then, the state-space equations of the DTL VSI and the grid-connected two-level voltage source inverter (TL VSI), regarding the presence of the phase-locked loop (PLL) and the VSG, are given. Next, the small-signal modeling of the DTL VSI and the TL VSI is realized. Eventually, the stability enhancement in the DTL VSI compared with the TL VSI is demonstrated. In the TL VSI, large values of virtual inertia could result in oscillations in the power system. However, the ability of the DTL VSI in damping oscillations is deduced. Furthermore, in the presence of nonlinear loads, the potentiality of the DTL VSI in reducing grid current Total Harmonic Distortion (THD) is evaluated. Finally, by using a proper reference current command signal, the abilities of the DTL VSI and the TL VSI in supplying nonlinear loads and providing virtual inertia are assessed simultaneously. The simulation results prove the advantages of the DTL VSI compared with the TL VSI in virtual inertia emulation and oscillation damping, which are realized by small-signal analysis.

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Convergence and stability analysis of the half thresholding based few-view CT reconstruction

Journal of Inverse and Ill-Posed Problems ◽

10.1515/jiip-2020-0003 ◽

2020 ◽

Vol 28 (6) ◽

pp. 829-847

Author(s):

Hua Huang ◽

Chengwu Lu ◽

Lingli Zhang ◽

Weiwei Wang

Keyword(s):

Noise Suppression ◽

Reconstructed Image ◽

Reference Image ◽

Projection Data ◽

Ct Reconstruction ◽

Reconstruction Algorithms ◽

Ill Posed ◽

Thresholding Algorithm ◽

The Stability ◽

Well Posed

AbstractThe projection data obtained using the computed tomography (CT) technique are often incomplete and inconsistent owing to the radiation exposure and practical environment of the CT process, which may lead to a few-view reconstruction problem. Reconstructing an object from few projection views is often an ill-posed inverse problem. To solve such problems, regularization is an effective technique, in which the ill-posed problem is approximated considering a family of neighboring well-posed problems. In this study, we considered the {\ell_{1/2}} regularization to solve such ill-posed problems. Subsequently, the half thresholding algorithm was employed to solve the {\ell_{1/2}} regularization-based problem. The convergence analysis of the proposed method was performed, and the error bound between the reference image and reconstructed image was clarified. Finally, the stability of the proposed method was analyzed. The result of numerical experiments demonstrated that the proposed method can outperform the classical reconstruction algorithms in terms of noise suppression and preserving the details of the reconstructed image.

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Attention Theory and Training Research

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128703100608 ◽

1987 ◽

Vol 31 (6) ◽

pp. 648-651 ◽

Cited By ~ 2

Author(s):

James G. Connelly ◽

Christopher D. Wickens ◽

Gavan Lintern ◽

Kelly Harwood

Keyword(s):

Mental Workload ◽

Open Loop ◽

Flight Simulation ◽

Complex Task ◽

Time Sharing ◽

Attention Theory ◽

Stimulus Response ◽

Training Research ◽

Complex Training ◽

The Stability

This study used elements of attention theory as a methodological basis to decompose a complex training task in order to improve training efficiency. The complex task was a microcomputer flight simulation where subjects were required to control the stability of their own helicopter while acquiring and engaging enemy helicopters in a threat environment. Subjects were divided into whole-task, part-task, and part/open loop adaptive task groups in a transfer of training paradigm. The effect of reducing mental workload at the early stages of learning was examined with respect to the degree that subordinate elements of the complex task could be automated through practice of consistent, learnable stimulus-response relationships. Results revealed trends suggesting the benefit of isolating consistently mapped sub-tasks for part-task training and the presence of a time-sharing skill over and above the skill required for the separate subtasks.

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