scholarly journals Suboptimal Disturbance Observer Design Using All Stabilizing Q Filter for Precise Tracking Control

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1434 ◽  
Author(s):  
Wonhee Kim ◽  
Sangmin Suh
Keyword(s):  
Design Method ◽  
Industrial Applications ◽  
Point Of View ◽  
Observer Design ◽  
Linear Matrix ◽  
External Disturbances ◽  
Closed Loop Systems ◽  
Control Target ◽  
The Stability ◽  
Unified Index

For several decades, disturbance observers (DOs) have been widely utilized to enhance tracking performance by reducing external disturbances in different industrial applications. However, although a DO is a verified control structure, a conventional DO does not guarantee stability. This paper proposes a stability-guaranteed design method, while maintaining the DO structure. The proposed design method uses a linear matrix inequality (LMI)-based H∞ control because the LMI-based control guarantees the stability of closed loop systems. However, applying the DO design to the LMI framework is not trivial because there are two control targets, whereas the standard LMI stabilizes a single control target. In this study, the problem is first resolved by building a single fictitious model because the two models are serial and can be considered as a single model from the Q-filter point of view. Using the proposed design framework, all-stabilizing Q filters are calculated. In addition, for the stability and robustness of the DO, two metrics are proposed to quantify the stability and robustness and combined into a single unified index to satisfy both metrics. Based on an application example, it is verified that the proposed method is effective, with a performance improvement of 10.8%.

scholarly journals Secure Load Frequency Control of Smart Grids under Deception Attack: A Piecewise Delay Approach

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2266 ◽  
Author(s):  
Fei Zhao ◽  
Jinsha Yuan ◽  
Ning Wang ◽  
Zhang Zhang ◽  
Helong Wen
Keyword(s):  
Smart Grids ◽  
Controller Design ◽  
Design Method ◽  
Frequency Control ◽  
Functional Method ◽  
Load Frequency Control ◽  
Linear Matrix ◽  
Load Frequency ◽  
The Stability

The problem of secure load frequency control of smart grids is investigated in this paper. The networked data transmission within the smart grid is corrupted by stochastic deception attacks. First, a unified Load frequency control model is constructed to account for both network-induced effects and deception attacks. Second, with the Lyapunov functional method, a piecewise delay analysis is conducted to study the stability of the established model, which is of less conservativeness. Third, based on the stability analysis, a controller design method is provided in terms of linear matrix inequalities. Finally, a case study is carried out to demonstrate the derived results.

scholarly journals Optimal Disturbance Observer Design for High Tracking Performance in Motion Control Systems

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1633
Author(s):  
Wonhee Kim ◽  
Sangmin Suh
Keyword(s):  
Disturbance Observer ◽  
Closed Loop ◽  
Inverse Dynamics ◽  
Hard Disk Drives ◽  
Observer Design ◽  
Disk Drives ◽  
Closed Loop Systems ◽  
Baseline Weight ◽  
The Stability ◽  
Target Plant

In this paper, a stability-driven optimal disturbance observer (DO) is proposed. The proposed method does not require any plant inverse dynamics to detect introduced disturbances or a stabilizing Q filter. It does not require additional compensators to resolve causality problems, due to the relative degree, or filters to solve instability problems of non-minimum phase plants. Using this method enables wideband and narrowband disturbances to be attenuated by simply multiplying the corresponding peak filters by the baseline weight function. Furthermore, the proposed DO guarantees the stability of closed-loop systems because the already designed outer-loop systems are considered as a target plant to be stabilized and because of the Lyapunov stability-based H∞ control. In the application example, it was confirmed that the proposed method is effective, and the position error signals were improved by 20.9% in commercial hard disk drives and 36.6% in optical image stabilization systems.

Reduction Methods of Structure Models for Control System Purposes

2016 ◽  
Vol 248 ◽  
pp. 119-126 ◽  
Author(s):  
Andrzej Koszewnik ◽  
Zdzisław Gosiewski
Keyword(s):  
Control System ◽  
High Frequency ◽  
Closed Loop ◽  
Flexible Structures ◽  
Low Frequency ◽  
Point Of View ◽  
Closed Loop Systems ◽  
System A ◽  
Reduction Methods ◽  
The Stability

To design vibration control system for flexible structures their mathematical model should be reduced. In the paper we consider the influence of the model reduction on the dynamics of the real closed-loop system. A simply cantilever beam is an object of consideration since we are able to formulate the exact analytical model of such structure. As a result of reduction the model with low frequency resonances is usually separated from the high frequency dynamics because high frequency part of the model is naturally strong damped. In order to estimate dynamical system for control purposes in the paper we applied a few orthogonal methods such as: modal, Rayleigh-Ritz and Schur decompositions. As it is shown all methods well calculate resonances frequencies but generate different anti-resonances frequencies. From control strategy in point of view of the flexible structures these anti-resonances have significantly influence on the stability and dynamics of the closed-loop systems.

Multiobjective Robust Regulating and Protecting Control for Aeroengines

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Daren Yu ◽  
Xiaofeng Liu ◽  
Wen Bao ◽  
Zhiqiang Xu
Keyword(s):  
Control Method ◽  
Design Method ◽  
Dynamic Performance ◽  
Switching Control ◽  
Linear Matrix ◽  
Matrix Inequality ◽  
Proportional Integral Derivative ◽  
Engine Control System ◽  
Switching Performance ◽  
The Stability

The multiobjective regulating and protecting control method presented here will enable improved control of multiloop switching control of an aeroengine. The approach is based on switching control theory, the switching performance objectives and the strategy are given, and a family of H∞ proportional-integral-derivative controllers was designed by using linear matrix inequality optimization algorithm. The simulation shows that using the switching control design method not only can improve the dynamic performance of the engine control system but also can guarantee the stability in some peculiar occasions.

scholarly journals A comparative study of nonlinear circle criterion based observer and H∞ observer for induction motor drive

2019 ◽  
Vol 10 (3) ◽  
pp. 1229
Author(s):  
Farid Berrezzek ◽  
Wafa Bourbia ◽  
Bachir Bensaker
Keyword(s):  
Comparative Study ◽  
Induction Motor ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Linear Matrix ◽  
Optimization Approach ◽  
Lmi Optimization ◽  
Circle Criterion ◽  
True State ◽  
The Stability

<span lang="EN-US">This paper deals with a comparative study of circle criterion based nonlinear observer<em> </em>and <em>H<sub>∞</sub></em> observer for induction motor (IM) drive. The  advantage of the circle criterion approach for nonlinear observer design is that it directly handles the nonlinearities of the system with less restriction  conditions in contrast of the other methods which attempt to eliminate them. However the <em>H<sub>∞</sub></em> observer guaranteed the stability taking into account disturbance and noise attenuation. Linear matrix inequality (LMI) optimization approach is used to compute the gains matrices for the two observers. The simulation results show the superiority of <em>H<sub>∞</sub></em> observer in the sense that it can achieve convergence to the true state, despite the nonlinearity of model and the presence of disturbance.</span>

scholarly journals Estimation Error Based Disturbance Observer Design for Flexible Loop Shaping

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 358 ◽  
Author(s):  
Sangmin Suh
Keyword(s):  
Disturbance Observer ◽  
Closed Loop ◽  
Control Structure ◽  
Storage Systems ◽  
Estimation Error ◽  
Observer Design ◽  
Experimental Results ◽  
External Disturbances ◽  
Flexible Loop ◽  
Closed Loop Systems

This note presents an estimation error based disturbance observer (EEDOB) to reduce the effects of external disturbances. In the proposed control structure, a difference between an estimator output and a plant output is considered as an equivalent disturbance. Therefore, when a disturbance appears, the proposed disturbance observer (DOB) is activated. Unlike conventional DOB, this method does not require the plant inverse model or additional stabilizing filters. In addition, the proposed method always satisfies closed loop systems stability, which is definitely different from conventional DOB. To verify the effectiveness, this method was applied to commercial storage systems. From the experimental results, it is confirmed that tracking performance is improved by 23.5%.

Adaptive Observer Design for Sensor Fault Detection and Reconstruction

2019 ◽  
Vol 20 (9) ◽  
pp. 515-523
Author(s):  
N. Bedioui ◽  
R. Houimli ◽  
M. Besbes
Keyword(s):  
Fault Detection ◽  
Sufficient Conditions ◽  
Main Idea ◽  
Observer Design ◽  
Adaptive Observer ◽  
Linear Matrix ◽  
Sensor Fault ◽  
Sensor Fault Detection ◽  
Robust Adaptive ◽  
The Stability

A new approach is presented for sensor fault detection reconstruction and state estimation. The system considered is linear polytopic parameter-vary ing (LPV) system. The main idea is the design of a novel robust adaptive observer based on and polyquadratic formulation with a new set of relaxation. Sufficient conditions are given by a set of Linear Matrix Inequalities (LMI) in order to guarantee the stability of the system and the asymptotic convergence of the fault error. A simulation example has been studied to illustrate the proposed methods by detecting constant and variable sensor fault.

Continuous-Time PDC-LMI Fuzzy Applied to 3SSC Boost Converter

2020 ◽  
Author(s):  
Jozias R. L. Neto ◽  
Luis Carvalho ◽  
Jefferson C. Rezende ◽  
Marcus V. S. Costa ◽  
Elenilson De Vargas Fortes
Keyword(s):  
Continuous Time ◽  
Output Voltage ◽  
Input Voltage ◽  
Boost Converter ◽  
Linear Matrix ◽  
External Disturbances ◽  
State Switching ◽  
Integral Action ◽  
Design Characteristics ◽  
The Stability

The application of DC-DC converters is widely approached in several studies to ensure its performance and robustness. This paper proposes the voltage control of a three-state switching cell (3SSC) boost converter in the continuous time. On this occasion, the output voltage is controlled by a Tagaki-Sugeno-Kang (TSK) Fuzzy with integral action, which thegains are obtained using Parallel Distributed Compensation via Linear Matrix Inequalities (PDC-LMI) combined through linear membership functions and activated by the duty cycle and inductor current. This approach aims to reject problems originated by load and input voltage variations and improve the stability response of the converter output voltage. The obtained results of this paper evidences the effectiveness of the proposed controller in the continuoustime, reducing the effects of external disturbances and maintaining the stability of the output voltage conforming to the control design characteristics.

scholarly journals Design of IIR Digital Filters with Arbitrary Flatness Using Iterative Quadratic Programming

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Yasunori Sugita
Keyword(s):  
Transfer Function ◽  
Digital Filters ◽  
Design Method ◽  
Infinite Impulse Response ◽  
Linear Matrix ◽  
Linear Phase ◽  
Iir Filters ◽  
Matrix Equality ◽  
Iir Digital Filters ◽  
The Stability

This paper presents a design method of Chebyshev-type and inverse-Chebyshev-type infinite impulse response (IIR) filters with an approximately linear phase response. In the design of Chebyshev-type filters, the flatness condition in the stopband is preincorporated into a transfer function, and an equiripple characteristic in the passband is achieved by iteratively solving the QP problem using the transfer function. In the design of inverse-Chebyshev-type filters, the flatness condition in the passband is added to the constraint of the QP problem as the linear matrix equality, and an equiripple characteristic in the stopband is realized by iteratively solving the QP problem. To guarantee the stability of the obtained filters, we apply the extended positive realness to the QP problem. As a result, the proposed method can design the filters with more high precision than the conventional methods. The effectiveness of the proposed design method is illustrated with some examples.

scholarly journals Feedback Gain Design Method for the Full-Order Flux Observer in Sensorless Control of Induction Motor

2008 ◽  
Vol 3 (2) ◽  
pp. 135 ◽  
Author(s):  
Abderrahmane Bouhenna ◽  
Abdellah Mansouri ◽  
Mohammed Chenafa ◽  
Abdelkader Belaidi
Keyword(s):  
Design Method ◽  
Observer Design ◽  
Necessary Condition ◽  
Feedback Gain ◽  
Unstable Region ◽  
Model Simulations ◽  
Flux Observer ◽  
The Stability ◽  
Linearized Model ◽  
Regenerating Mode

This paper deals with a feedback gain design method for the full-order flux observer with adaptive speed loop, which enables the minimizing the unstable operation region of this observer to a line in the torque-speed plane. The stability in regenerating mode is studied using necessary condition of stability based on determinant of matrix and a linearized model. Simulations results where the proposed observer is compared with an exiting solution (where the unstable region is not totally removed) are presented to validate the proposed observer design.

Sign in / Sign up

Export Citation Format

Share Document