LPV-Based-Method Aiming at a Win-Win Situation for Analytical Control Theories and Intelligent Optimization Methodologies

2009 ◽  
Author(s):  
Kazuhiko Hiramoto
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Control Method ◽  
Control Object ◽  
Gain Scheduling ◽  
Design Parameters ◽  
Analytical Control ◽  
Time Varying ◽  
Intelligent Optimization ◽  
Gain Scheduling Control

A new collaborative control strategy between time varying design parameters in LPV plants and the feedback controllers is proposed in the present paper. As the feedback control law the gain scheduling control scheme is adopted to guarantee the closed-loop L2 gain performance against the variation of the time varying parameter in the control object. The gain-scheduling controller can be obtained in an analytical manner by solving LMIs. For the closed-loop system with the LPV plant and the gain scheduling controller Genetic algorithm (GA), known as a so-called intelligent optimization method, is applied to optimize the closed-loop response. The proposed control system has a complementary structure between the LMI-based analytical control strategy and the flexible intelligent control method that does not impair their advantages each other. In this sense a win-win situation for the LMI-based gain scheduling control and the GA-based intelligent optimization is realized in the proposed approach. A simple simulation example is presented to show the effectiveness of the proposed method.

scholarly journals Design of Gain Scheduling Control Using State Derivative Feedback

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Lázaro Ismael Hardy Llins ◽  
Edvaldo Assunção ◽  
Marcelo C. M. Teixeira ◽  
Rodrigo Cardim ◽  
Mario R. R. Cadalso ◽  
...  
Keyword(s):  
Control Theory ◽  
Mechanical System ◽  
Control Strategy ◽  
Sufficient Conditions ◽  
Gain Scheduling ◽  
The State ◽  
Practical Implementation ◽  
Time Varying ◽  
Time Varying Parameters ◽  
Gain Scheduling Control

In recent years, the study of systems subject to time-varying parameters has awakened the interest of many researchers. The gain scheduling control strategy guarantees a good performance for systems of this type and also is considered as the simplest to deal with problems of this nature. Moreover, the class of systems in which the state derivative signals are easier to obtain than the state signals, such as in the control for reducing vibrations in a mechanical system, has gained an important hole in control theory. Considering those ideas, we propose sufficient conditions via LMI for designing a gain scheduling controller using state derivative feedback. The D-stability methodology was used for improving the performance of the transitory response. Practical implementation in an active suspension system and comparison with other methods validates the efficiency of the proposed strategy.

scholarly journals Efficient adaptive constrained control with time-varying predefined performance for a hypersonic flight vehicle

2017 ◽  
Vol 14 (2) ◽  
pp. 172988141668750 ◽  
Author(s):  
Caisheng Wei ◽  
Jianjun Luo ◽  
Honghua Dai ◽  
Jianping Yuan ◽  
Jianfeng Xie
Keyword(s):  
Control Method ◽  
Low Complexity ◽  
Least Square ◽  
Design Parameters ◽  
Support Vector ◽  
Time Varying ◽  
Flight Vehicle ◽  
Performance Function ◽  
Hypersonic Flight Vehicle ◽  
Hypersonic Flight

A novel low-complexity adaptive control method, capable of guaranteeing the transient and steady-state tracking performance in the presence of unknown nonlinearities and actuator saturation, is investigated for the longitudinal dynamics of a generic hypersonic flight vehicle. In order to attenuate the negative effects of classical predefined performance function for unknown initial tracking errors, a modified predefined performance function with time-varying design parameters is presented. Under the newly developed predefined performance function, two novel adaptive controllers with low-complexity computation are proposed for velocity and altitude subsystems of the hypersonic flight vehicle, respectively. Wherein, different from neural network-based approximation, a least square support vector machine with only two design parameters is utilized to approximate the unknown hypersonic dynamics. And the relevant ideal weights are obtained by solving a linear system without resorting to specialized optimization algorithms. Based on the approximation by least square support vector machine, only two adaptive scalars are required to be updated online in the parameter projection method. Besides, a new finite-time-convergent differentiator, with a quite simple structure, is proposed to estimate the unknown generated state variables in the newly established normal output-feedback formulation of altitude subsystem. Moreover, it is also employed to obtain accurate estimations for the derivatives of virtual controllers in a recursive design. This avoids the inherent drawback of backstepping — “explosion of terms” and makes the proposed control method achievable for the hypersonic flight vehicle. Further, the compensation design is employed when the saturations of the actuator occur. Finally, the numerical simulations validate the efficiency of the proposed finite-time-convergent differentiator and control method.

A Control Method for Non-Linear Time-Varying System Using Mixed H2/H∞ Control: Position and Force Control of 2-Link Manipulator

2001 ◽  
Author(s):  
Itsuro Kajiwara ◽  
Katsuhiro Yambe ◽  
Chiaki Nishidome
Keyword(s):  
Control Method ◽  
Linear Time ◽  
Gain Scheduling ◽  
Operating Conditions ◽  
Pole Placement ◽  
Time Varying ◽  
Linear Time Invariant ◽  
Highly Nonlinear ◽  
Switching Controller ◽  
Time Invariant

Abstract Dynamics of multi-link manipulators are highly nonlinear and depend on the time varying configuration. This paper presents a method of gain scheduling which consists in designing a linear time invariant (LTI) controller for each operating point and in switching controller when the operating conditions change. Each LTI controller is designed based on LMI approach in which an optimization problem is defined as a mixed H2/H∞ control problem with pole placement. The performance of the force and the position controls is defined by the H2 norm, and the robust stability according to gain scheduling is evaluated with the H∞ norm and the pole placement of the closed-loop system. The effectiveness and the practicability of the proposed method are verified by both simulations and experiments with 2-link manipulator system.

The Time-Varying Fractional Order Difference Equations

2003 ◽  
Author(s):  
Piotr W. Ostalczyk
Keyword(s):  
Dynamical Systems ◽  
Fractional Order ◽  
Difference Equations ◽  
Control Strategy ◽  
Closed Loop ◽  
Time Varying ◽  
Linear Difference Equations ◽  
Order Difference ◽  
Numerical Example ◽  
Fractional Orders

In this paper we explore the linear difference equations with fractional orders being a function of time. A description of closed-loop dynamical systems described by such equations is proposed. In the numerical example a simple control strategy based on time-varying fractional orders is presented.

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