Fractional Order Filter Enhanced LQR for Seismic Protection of Civil Structures

2008 ◽  
Vol 3 (2) ◽  
Author(s):  
Abdollah Shafieezadeh ◽  
Keri Ryan ◽  
YangQuan Chen
Keyword(s):  
Fractional Order ◽  
Ground Motions ◽  
Linear Quadratic Regulator ◽  
Performance Criterion ◽  
Seismic Protection ◽  
State Variables ◽  
Linear Quadratic ◽  
Civil Structures ◽  
Order Filter ◽  
Earthquake Data

This study presents fractional order filters to enhance the performance of the conventional linear quadratic regulator (LQR) method for optimal robust control of a simple civil structure. The introduced filters modify the state variables fed back to the constant gain controller. Four combinations of fractional order filter and LQR are considered and optimized based on a new performance criterion defined in the paper. Introducing fractional order filters is shown to considerably improve the results for both the artificially generated ground motions and previously recorded earthquake data.

Fractional Order LQR for Optimal Robust Control of a Simple Structure

2007 ◽  
Author(s):  
Abdollah Shafieezadeh ◽  
Keri Ryan ◽  
YangQuan Chen
Keyword(s):  
Robust Control ◽  
Control Problem ◽  
Fractional Order ◽  
Simple Structure ◽  
Control Method ◽  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
Fractional Damping ◽  
Fractional Order Control

This study combines fractional order control with linear quadratic regulator (LQR) for optimal robust control of a simple civil structure. As a first attempt, the purpose of this paper is to demonstrate that, when fractional damping is introduced, additional benefits can be obtained over the best traditional control method. The control problem of this paper can be used as a simple benchmark example to test new control ideas before applying to more complicated models.

scholarly journals Fractional-Order Fuzzy Control Approach for Photovoltaic/Battery Systems under Unknown Dynamics, Variable Irradiation and Temperature

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1455
Author(s):  
Amirhosein Mosavi ◽  
Sultan Noman Qasem ◽  
Manouchehr Shokri ◽  
Shahab S. Band ◽  
Ardashir Mohammadzadeh
Keyword(s):  
Fractional Order ◽  
Sliding Mode ◽  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
Fuzzy Logic Systems ◽  
Control Approach ◽  
Operation Conditions ◽  
Battery Systems ◽  
Temperature Variable ◽  
Voltage Management

For this paper, the problem of energy/voltage management in photovoltaic (PV)/battery systems was studied, and a new fractional-order control system on basis of type-3 (T3) fuzzy logic systems (FLSs) was developed. New fractional-order learning rules are derived for tuning of T3-FLSs such that the stability is ensured. In addition, using fractional-order calculus, the robustness was studied versus dynamic uncertainties, perturbation of irradiation, and temperature and abruptly faults in output loads, and, subsequently, new compensators were proposed. In several examinations under difficult operation conditions, such as random temperature, variable irradiation, and abrupt changes in output load, the capability of the schemed controller was verified. In addition, in comparison with other methods, such as proportional-derivative-integral (PID), sliding mode controller (SMC), passivity-based control systems (PBC), and linear quadratic regulator (LQR), the superiority of the suggested method was demonstrated.

scholarly journals Fractional-Order LQR and State Observer for a Fractional-Order Vibratory System

2021 ◽  
Vol 11 (7) ◽  
pp. 3252
Author(s):  
Akihiro Takeshita ◽  
Tomohiro Yamashita ◽  
Natsuki Kawaguchi ◽  
Masaharu Kuroda
Keyword(s):  
Fractional Order ◽  
Linear Quadratic Regulator ◽  
State Observer ◽  
State Equation ◽  
Algebraic Riccati Equation ◽  
Linear Quadratic ◽  
Vibratory System ◽  
Derivative Term ◽  
Numerical Calculation Method ◽  
Order State

The present study uses linear quadratic regulator (LQR) theory to control a vibratory system modeled by a fractional-order differential equation. First, as an example of such a vibratory system, a viscoelastically damped structure is selected. Second, a fractional-order LQR is designed for a system in which fractional-order differential terms are contained in the equation of motion. An iteration-based method for solving the algebraic Riccati equation is proposed in order to obtain the feedback gains for the fractional-order LQR. Third, a fractional-order state observer is constructed in order to estimate the states originating from the fractional-order derivative term. Fourth, numerical simulations are presented using a numerical calculation method corresponding to a fractional-order state equation. Finally, the numerical simulation results demonstrate that the fractional-order LQR control can suppress vibrations occurring in the vibratory system with viscoelastic damping.

COMPARISON OF HYSTERESIS CONTROL AND REDUCED ORDER LINEAR QUADRATIC REGULATOR CONTROL FOR POWER FACTOR CORRECTION USING DC–DC CUK CONVERTERS

2012 ◽  
Vol 21 (01) ◽  
pp. 1250002 ◽  
Author(s):  
M. G. UMAMAHESWARI ◽  
G. UMA ◽  
S. REDLINE VIJITHA
Keyword(s):  
Power Factor ◽  
Power Factor Correction ◽  
Linear Quadratic Regulator ◽  
Voltage Regulation ◽  
Experimental Results ◽  
Linear Quadratic ◽  
Reduced Order ◽  
Order Linear ◽  
Hysteresis Controller ◽  
Set Up

This paper focuses on a comparative study of a reduced order linear quadratic regulator control (ROLQR) and conventional variable frequency hysteresis controller (HC) for power factor correction, and their performances are compared. A prototype of front-end AC–DC converter followed by DC–DC Cuk converter controlled by a dSPACE signal processor was set up for 60 watts. Experimental results are presented to validate the simulation results. Simulation and experimental results reveal that ROLQR control can achieve good output voltage regulation and also provide improved robustness in shaping the input current in the presence of load variations when compared to conventional HC.

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