scholarly journals Fuzzy Control of DC-DC Converters with Input Constraint

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
D. Saifia ◽  
M. Chadli ◽  
S. Labiod ◽  
H. R. Karimi
Keyword(s):  
Fuzzy Control ◽  
State Feedback ◽  
Controller Design ◽  
Actuator Saturation ◽  
External Disturbance ◽  
Fuzzy Model ◽  
Feedback System ◽  
Input Constraint ◽  
Lyapunov Approach ◽  
System A

This paper proposes a method for designing fuzzy control of DC-DC converters under actuator saturation. Because linear control design methods do not take into account the nonlinearity of the system, a T-S fuzzy model and a controller design approach is used. The designed control not only handles the external disturbance but also the saturation of duty cycle. The input constraint is first transformed into a symmetric saturation which is represented by a polytopic model. Stabilization conditions for the state feedback system of DC-DC converters under actuator saturation are established using the Lyapunov approach. The proposed method has been compared and verified with a simulation example.

scholarly journals Actuator Saturated Fuzzy Controller Design for Interval Type-2 Takagi-Sugeno Fuzzy Models with Multiplicative Noises

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 823
Author(s):  
Wen-Jer Chang ◽  
Yu-Wei Lin ◽  
Yann-Horng Lin ◽  
Chin-Lin Pen ◽  
Ming-Hsuan Tsai
Keyword(s):  
Nonlinear Systems ◽  
Fuzzy Controller ◽  
Controller Design ◽  
Actuator Saturation ◽  
Design Method ◽  
Fuzzy Model ◽  
The Stability ◽  
Interval Type ◽  
Takagi Sugeno

In many practical systems, stochastic behaviors usually occur and need to be considered in the controller design. To ensure the system performance under the effect of stochastic behaviors, the controller may become bigger even beyond the capacity of practical applications. Therefore, the actuator saturation problem also must be considered in the controller design. The type-2 Takagi-Sugeno (T-S) fuzzy model can describe the parameter uncertainties more completely than the type-1 T-S fuzzy model for a class of nonlinear systems. A fuzzy controller design method is proposed in this paper based on the Interval Type-2 (IT2) T-S fuzzy model for stochastic nonlinear systems subject to actuator saturation. The stability analysis and some corresponding sufficient conditions for the IT2 T-S fuzzy model are developed using Lyapunov theory. Via transferring the stability and control problem into Linear Matrix Inequality (LMI) problem, the proposed fuzzy control problem can be solved by the convex optimization algorithm. Finally, a nonlinear ship steering system is considered in the simulations to verify the feasibility and efficiency of the proposed fuzzy controller design method.

scholarly journals Predictor-based stabilization for chained form systems with input time delay

2016 ◽  
Vol 26 (4) ◽  
pp. 515-525
Author(s):  
Faïçal Mnif
Keyword(s):  
Time Delay ◽  
State Feedback ◽  
Original System ◽  
Feedback System ◽  
State Feedback Control ◽  
Exponential Stabilization ◽  
Free System ◽  
System A ◽  
Input Time ◽  
System States

Abstract This note addresses the stabilization problem of nonlinear chained-form systems with input time delay. We first employ the so-called σ-process transformation that renders the feedback system under a linear form. We introduce a particular transformation to convert the original system into a delay-free system. Finally, we apply a state feedback control, which guarantees a quasi-exponential stabilization to all the system states, which in turn converge exponentially to zero. Then we employ the so-called -type control to achieve a quasi-exponential stabilization of the subsequent system. A simulation example illustrated on the model of a wheeled mobile robot is provided to demonstrate the effectiveness of the proposed approach.

Switching Fuzzy Model Construction and Controller Design for Dynamical Systems with Input Nonlinearity

2008 ◽  
Vol 12 (6) ◽  
pp. 537-545 ◽  
Author(s):  
Hiroshi Ohtake ◽  
◽  
Kazuo Tanaka
Keyword(s):  
Dynamical Systems ◽  
State Feedback ◽  
Controller Design ◽  
Fuzzy Model ◽  
Construction Method ◽  
Model Construction ◽  
Dynamic State ◽  
Membership Functions ◽  
Input Nonlinearity ◽  
Control Approach

Fuzzy model-based control mainly deals with dynamical systems which affinely depend on control inputs. In this paper, dynamical systems which is permitted to have nonlinearity not only in the states, but also in the inputs is considered. Input nonlinearity makes a nonlinear system complicated and makes the number of fuzzy model rules increase. Thus, switching fuzzy control approach is employed. Firstly, the switching fuzzy model construction with arbitrary linear dividing planes, which is an extension of the ordinary switching fuzzy model construction method with dividing planes corresponding to quadrants, is introduced. Secondly, by applying the switching fuzzy model construction method to the dynamical system with input nonlinearity, the switching fuzzy model with membership functions which depend on control inputs is constructed. Finally, by utilizing the dynamic state feedback control approach, we show that membership functions which depend on control inputs can be calculated. Moreover, by employing augmented system approach, the switching fuzzy dynamic state feedback controller design conditions based on the switching Lyapunov function are derived in terms of linear matrix inequalities. A design example illustrates the utility of this approach.

APPLICATION AND ROBUSTNESS DESIGN OF FUZZY CONTROLLER FOR RESONANT AND CHAOTIC SYSTEMS WITH EXTERNAL DISTURBANCE

2005 ◽  
Vol 13 (03) ◽  
pp. 281-295 ◽  
Author(s):  
FENG-HSIAG HSIAO ◽  
WEI-LING CHIANG ◽  
CHENG-WU CHEN ◽  
SHENG-DONG XU ◽  
SHIH-LIN WU
Keyword(s):  
Chaotic Systems ◽  
Fuzzy Controller ◽  
Controller Design ◽  
Design Method ◽  
Direct Method ◽  
External Disturbance ◽  
Approximation Error ◽  
Fuzzy Model ◽  
Linear Matrix ◽  
Resonant Systems

A robustness design of fuzzy control via model-based approach is proposed in this paper to overcome the effect of approximation error between nonlinear system and Takagi-Sugeno (T-S) fuzzy model. T-S fuzz model is used to model the resonant and chaotic systems and the parallel distributed compensation (PDC) is employed to determine structures of fuzzy controllers. Linear matrix inequality (LMI) based design problems are utilized to find common definite matrices P and feedback gains K satisfying stability conditions derived in terms of Lyapunov direct method. Finally, the effectiveness and the feasibility of the proposed controller design method is demonstrated through numerical simulations on the chaotic and resonant systems.

scholarly journals Aircraft Flight Stabilizer System by CDM Designed Servo State-Feedback Controller

Aerospace ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 45
Author(s):  
Ekachai Asa ◽  
Yoshio Yamamoto
Keyword(s):  
Flight Control ◽  
State Feedback ◽  
Controller Design ◽  
Nonlinear Models ◽  
Feedback System ◽  
Flight Control System ◽  
Diagram Method ◽  
Performance Requirement ◽  
Directional Motion ◽  
Coefficient Diagram Method

This research presents an automatic flight control system whose advantage is its ease of modification or maintenance while still effectively meeting the system’s performance requirement. This research proposes a mixed servo state-feedback system for controlling aircraft longitudinal and lateral-directional motion simultaneously based on the coefficient diagram method or CDM as the controller design methodology. The structure of this mixed servo state-feedback system is intuitive and straightforward, while CDM’s design processes are clear. Simulation results with aircraft linear and nonlinear models exhibit excellent performance in stabilizing and tracking the reference commands for both longitudinal and lateral-directional motion.

Delay-dependent stability criterion for uncertain discrete time systems in presence of actuator saturation

2017 ◽  
Vol 40 (6) ◽  
pp. 1873-1891 ◽  
Author(s):  
Vipin Chandra Pal ◽  
Richa Negi
Keyword(s):  
Discrete Time ◽  
Controller Design ◽  
Actuator Saturation ◽  
External Disturbance ◽  
Linear Matrix ◽  
Time Varying Delay ◽  
Discrete Time Systems ◽  
The Stability ◽  
Delay Dependent ◽  
Time Systems

In this paper, the idea of triple Lyapunov functional is applied for controller design of discrete time systems subjected to various nonlinearities like actuator saturation, time varying delay and uncertainties. The performance of the system considered has been examined using H∞ technique in presence of external disturbance. A novel augmented triple Lyapunov-Krasovskii functional is applied with reciprocal convex approach to achieve the stability conditions, which are based on Linear Matrix Inequality. Saturation nonlinearity is tackled using less conservative convex hull method. Numerical examples are provided to illustrate the effectiveness of the proposed criterion.

Further Results on T-S Fuzzy Controller Design Subject to Input Constraint

2008 ◽  
Vol 12 (2) ◽  
pp. 190-197 ◽  
Author(s):  
Hugang Han ◽  
Keyword(s):  
Fuzzy Controller ◽  
Controller Design ◽  
Fuzzy Model ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Input Constraint ◽  
Initial State ◽  
Control Gain ◽  
Matrix Variable ◽  
Takagi Sugeno

In general, when using the Takagi-Sugeno (T-S) fuzzy model to develop a control system, the state feedback control gain can be obtained by solving some linear matrix inequalities (LMIs). In this paper, we consider a class of nonlinear systems with input constraint (saturation). To obtain the control gain, we require to employ certain extra LMIs besides the general ones. As a result, all the LMIs are more conservative. At the same time, one of the extra LMIs confines the initial state to a region, which is referred to as an ellipsoid, and is relevant to a matrix variable in the LMIs. Therefore, the goals of this paper are: 1) making the ellipsoid as large as possible so that the initial state can be confined to the region easily and; 2) making all the LMIs more feasible to obtain the control gain.

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