scholarly journals A Robust Controller for Multivariable Model Matching System Utilizing a Quantitative Feedback Theory: Application to Magnetic Levitation

2019 ◽  
Vol 9 (9) ◽  
pp. 1753 ◽  
Author(s):  
Ramamurthy Jeyasenthil ◽  
Seung-Bok Choi
Keyword(s):  
Controller Design ◽  
Magnetic Levitation ◽  
Design Method ◽  
External Disturbance ◽  
Uncertain System ◽  
Disturbance Attenuation ◽  
Model Matching ◽  
Quantitative Feedback Theory ◽  
Matching Problem ◽  
And Control

This paper proposes a systematic feedback controller design methodology for multi-input multi-output (MIMO) uncertain systems using the quantitative feedback theory (QFT). To achieve this goal, the model matching problem was considered and the inversion feedforward controller was designed to improve control performance while reducing the demand on feedback control alone. The proposed method is formulated based on the concept of equivalent disturbance attenuation (EDA) approach in which the uncertain system problem is converted into an external disturbance rejection problem based on a nominal system. This proposed approach exhibiting non-sequential design method result in the suboptimal solution showing design simplicity and computational efficiency compared to the existing method. In order to validate the effectiveness of the proposed control methodology, the MIMO magnetic levitation system as adopted and control performances such as time response were presented in both time and frequency domains.

A Simplified Multi-Input Multi-Output Formulation for the Quantitative Feedback Theory

1992 ◽  
Vol 114 (2) ◽  
pp. 179-185 ◽  
Author(s):  
O. Yaniv ◽  
Y. Chait
Keyword(s):  
Linear Functions ◽  
Model Matching ◽  
Quantitative Feedback Theory ◽  
Matching Problem ◽  
Performance Constraints ◽  
Robust Model ◽  
Traditional Procedure ◽  
Step Procedure ◽  
Loop Transfer Function ◽  
And Control

A simplified multi input/output formulation is developed for the quantitative feedback theory (QFT) for the 2 × 2 (n = 2) case. This formulation is consistent with traditional QFT philosophy where performance is specified for each individual closed-loop transfer function and control bandwidths are minimized. The simplified formulation turns the solution of a simultaneous robust stability and robust model matching problem into a two (n in general) step procedure of solving quadratic inequalities (whose coefficients are linear functions of the plants and the performance constraints); the traditional procedure requires six (n + n2 in general) steps for a similar problem. A numerical example illustrates the simplified formulation and demonstrates its ability to offer useful insight in a control design.

Multi Mode Vibration Control and Broder Band Motion Control of Three Dimensional Shaking Table

2005 ◽  
Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
Mode Vibration ◽  
And Control

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.

scholarly journals The discrete-time tracking problem with H∞ model matching approach plus integral control

2019 ◽  
Vol 292 ◽  
pp. 01018
Author(s):  
Murat Akın ◽  
Tankut Acarman
Keyword(s):  
Discrete Time ◽  
Closed Loop ◽  
Controller Design ◽  
Model Matching ◽  
Matching Problem ◽  
Design Algorithm ◽  
Integral Control ◽  
Loop Transfer Function ◽  
Model Transfer ◽  
Static Output

In this study, the discrete-time H∞ model matching problem with integral control by using 2 DOF static output feedback is presented. First, the motivation and the problem is stated. After presenting the notation, the two lemmas toward the discrete-time H∞ model matching problem with integral control are proven. The controller synthesis theorem and the controller design algorithm is elaborated in order to minimize the H∞ norm of the closed-loop transfer function and to maximize the closed-loop performance by introducing the model transfer matrix. In following, the discrete-time H∞ MMP via LMI approach is derived as the main result. The controller construction procedure is implemented by using a well-known toolbox to improve the usability of the presented results. Finally, some conclusions are given.

A New Iterative Identification and Control Method of Closed-Loop Power System Based on Ambient Signals

2015 ◽  
Vol 798 ◽  
pp. 261-265
Author(s):  
Miao Yu ◽  
Chao Lu
Keyword(s):  
Power System ◽  
Closed Loop ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Stability Margin ◽  
System Stability ◽  
Iterative Identification ◽  
Effective Performance ◽  
And Control

Identification and control are important problems of power system based on ambient signals. In order to avoid the model error influence of the controller design, a new iterative identification and control method is proposed in this paper. This method can solve model set and controller design of closed-loop power system. First, an uncertain model of power system is established. Then, according to the stability margin of power system, stability theorem is put forward. And then controller design method and the whole algorithm procedure are given. Simulation results show the effective performance of the proposed method based on the four-machine-two-region system.

scholarly journals Robust Control for Autonomous Spacecraft Evacuation with Model Uncertainty and Upper Bound of Performance with Constraints

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Dian Sheng ◽  
Xuebo Yang ◽  
Hamid Reza Karimi
Keyword(s):  
Upper Bound ◽  
Controller Design ◽  
Design Method ◽  
Disturbance Attenuation ◽  
Linear Matrix ◽  
Fuel Cost ◽  
Convex Optimization Problem ◽  
Output Tracking ◽  
Guaranteed Cost ◽  
Initial States

This paper studies the problem of guaranteed cost control for spacecraft evacuation. The relative dynamic model is established based on Clohessy-Wiltshire (C-W) equations. The paper has taken parameter uncertainty, output tracking, disturbance attenuation, and fuel cost into consideration. The paper introduces a new Lyapunov approach, so the controller design problem can be transferred into a convex optimization problem subject to linear matrix inequality (LMI) constraints. By using the controller, the spacecraft evacuation can be completed in a safe extent. Meanwhile, the fuel cost also has an upper bound. Then the paper analyzes the approach of evacuation and discusses possible initial states of the spacecraft for the controller design. An illustrative example is applied to show the effectiveness of the proposed control design method, and different performances caused by different initial states of spacecraft (-V-bar, -R-bar, and +H-bar) are simulated.

scholarly journals Design of a Preview Controller for Discrete-Time Systems Based on LMI

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Li Li ◽  
Fucheng Liao
Keyword(s):  
Steady State ◽  
Discrete Time ◽  
Controller Design ◽  
Design Method ◽  
Reference Signal ◽  
Original System ◽  
Disturbance Attenuation ◽  
Linear Matrix ◽  
Discrete Time Systems ◽  
Time Systems

A preview controller design method for discrete-time systems based on LMI is proposed. First, we use the difference between a system state and its steady-state value, instead of the usual difference between system states, to transform the tracking problem into a regulator problem. Then, based on the Lyapunov stability theory and linear matrix inequality (LMI) approach, the preview controller ensuring asymptotic stability of the closed-loop system for the derived augmented error system is found. And an extended functional observer is designed in this paper which can achieve disturbance attenuation in the estimation process; as a result, the state of the system can be reconstructed rapidly and accurately. The controller gain matrix is obtained by solving an LMI problem. By incorporating the controller obtained into the original system, we obtain the preview controller of the system under consideration. To make sure that the output tracks the reference signal without steady-state error, an integrator is introduced. The numerical simulation example also illustrates the effectiveness of the results in the paper.

Decentralized Robust Vibration Control of Smart Structures with Parameter Uncertainties

2011 ◽  
Vol 22 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Jian-Ping Jiang ◽  
Dong-Xu Li
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Damping Ratio ◽  
External Disturbance ◽  
Composite Panel ◽  
Linear Matrix ◽  
Control Input ◽  
Parameter Uncertainties ◽  
Modal Damping ◽  
And Control

This study deals with decentralized robust vibration control of a smart composite panel with parameter uncertainties. The composite panel with four collocated piezoelectric actuators and velocity sensors is modeled using finite element method, and then the size of the model is reduced in the state space using Modal Hankel Singular Value. The parameter uncertainties presented by natural frequencies and modal damping ratios are considered in controller design process. To suppress the vibration induced by external disturbance, a decentralized robust H∞ controller is developed using linear matrix inequality techniques. Numerical simulation for the smart panel is performed in order to investigate the effectiveness of decentralized vibration control (DVC). When the system is subjected to an initial displacement field or distributed white noise disturbance, numerical results show that the DVC system is very effective. Although there are 20% parameter uncertainties for modal frequencies, damping ratio, and control input, the decentralized controller can effectively suppress the vibration excited by the external disturbance. Furthermore, the decentralized controller composed of four three-order systems can be practically implemented well.

scholarly journals Diagonally dominant backstepping autopilot for aircraft with unknown actuator failures and severe winds

2014 ◽  
Vol 118 (1207) ◽  
pp. 1009-1038 ◽  
Author(s):  
S. Ismail ◽  
A. A. Pashilkar ◽  
R. Ayyagari ◽  
N. Sundararajan
Keyword(s):  
Dynamic Models ◽  
Controller Design ◽  
Design Method ◽  
Equations Of Motion ◽  
Control Surface ◽  
Actuator Failures ◽  
Time Scale Separation ◽  
Diagonally Dominant ◽  
Trajectory Following ◽  
And Control

Abstract A novel formulation of the flight dynamic equations is presented that permits a rapid solution for the design of trajectory following autopilots for nonlinear aircraft dynamic models. A robust autopilot control structure is developed based on the combination of the good features of the nonlinear dynamic inversion (NDI) method, integrator backstepping method, time scale separation and control allocation methods. The aircraft equations of motion are formulated in suitable variables so that the matrices involved in the block backstepping control design method are diagonally dominant. This allows us to use a linear controller structure for a trajectory following autopilot for the nonlinear aircraft model using the well known loop by loop controller design approach. The resulting autopilot for the fixed-wing rigid-body aircraft with a cascaded structure is referred to as the diagonally dominant backstepping (DDBS) controller. The method is illustrated here for an aircraft auto-landing problem under unknown actuator failures and severe winds. The requirement of state and control surface limiting is also addressed in the context of the design of the DDBS controller.

scholarly journals Guidance Law and Neural Control for Hypersonic Missile to Track Targets

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Wenxing Fu ◽  
Binbin Yan ◽  
Xiaofei Chang ◽  
Jie Yan
Keyword(s):  
Neural Control ◽  
Controller Design ◽  
Sliding Mode ◽  
External Disturbance ◽  
Control Laws ◽  
Guidance And Control ◽  
Maneuvering Target ◽  
Guidance Law ◽  
Control Command ◽  
And Control

Hypersonic technology plays an important role in prompt global strike. Because the flight dynamics of a hypersonic vehicle is nonlinear, uncertain, and highly coupled, the controller design is challenging, especially to design its guidance and control law during the attack of a maneuvering target. In this paper, the sliding mode control (SMC) method is used to develop the guidance law from which the desired flight path angle is derived. With the desired information as control command, the adaptive neural control in discrete time is investigated ingeniously for the longitudinal dynamics of the hypersonic missile. The proposed guidance and control laws are validated by simulation of a hypersonic missile against a maneuvering target. It is demonstrated that the scheme has good robustness and high accuracy to attack a maneuvering target in the presence of external disturbance and missile model uncertainty.

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