Authors:
Rainer Palm,
Christiane Stutz,
Thomas Runkler,
Volume: 1, Page 370 Paper number 1252
Abstract:
The generation of the sequence of control inputs along a given state
trajectory for a nonlinear system is described. A nonlinear system
is linearized at predefined points in the product space of the states
and control inputs and then approximated by local linear fuzzy models.
Based on this approximation the system is controlled by a set of local
linear Takagi-Sugeno fuzzy controllers. The local control laws designed
for the error system incorporate both the desired and the actual state
as well as the corresponding control input. Normally, the desired
state is defined by the user but the related control input cannot always
be calculated in a unique way especially for a non-square system. The
proposed method generates the desired control inputs on the basis of
the states and its derivatives using inverse fuzzy models of the system.
In an optimization loop the control inputs are corrected by the analytical
forward model of the nonlinear system.
Authors:
Farrokh Janabi-Sharifi,
Jiang Fan,
Volume: 1, Page 376 Paper number 1312
Abstract:
This paper deals with the problem of looper control for tension-free
rolling. Conventional controllers cannot deal effectively with unmodeled
dynamics and large variations which can lead to scrap runs and damages
to machinery. Therefore, a fuzzy controller has been designed to use
the expert knowledge of the operators for disturbed process control.
Also, a self-tuning algorithm is incorporated for both on-line and
off-line tuning of the fuzzy membership functions. This paper discusses
the design of the fuzzy logic controller and its self-tuning. The
effects of various design options are discussed and practical conclusions
are made. Results from simulations are also presented.
Authors:
Akram M. Fayaz,
Volume: 1, Page 382 Paper number 1881
Abstract:
In this paper T-S fuzzy observers and controllers, built for the plants
represented by T-S models, are analyzed from the interpolation viewpoint.
The notion of fuzzy stability covering condition is defined extending
the definition given in the "classical interpolation" case. Assuming
slow variations of a so-called interpolating variable, sufficient conditions
are given in order to generate stable parameter-varying family of observers
and controllers that estimate the states and, stabilize nonlinear plants.
Authors:
Chih-Lyang Hwang,
Volume: 1, Page 388 Paper number 38
Abstract:
Based on the system relative degree, the frictional servosystem is
transformed into external and internal parts. By using a feedback linearizing
control, the external part becomes a linear dynamic system with uncertainties.
A reference model with the desired amplitude and phase properties is
given to obtain an error dynamics in the presence of uncertainties.
The unmatched uncertainty is also examined. To improve the system performance,
an on-line fuzzy-model is employed to model these uncertainties in
a compact subset. An updating law with e-modification for the weight
of fuzzy-model is designed to obtain an effective learning of the uncertainties.
Then, an equivalent control using the known part of frictional servosystem
and the learning fuzzy-model of uncertainties is established to achieve
the desired result. The unmodeled dynamics caused by the error of approximated
fuzzy-model and estimated weight are tackled by a switching control.
In summary, the adaptive fuzzy control includes two parts: a feedback
linearizing control with a reference model and an adaptive fuzzy variable
structure control (AFVSC). The stability of the overall system is then
verified by the Lyapunov theory so that the uniformly ultimately bounded
tracking is accomplished. Simulations are also presented to verify
the usefulness of the proposed control.
Authors:
Gang Feng,
Volume: 1, Page 394 Paper number 1007
Abstract:
In this paper we address the issues of universal fuzzy controllers
for discrete time systems. We first present a universal function approximation
theorem based on a fuzzy dynamic model. Then we show the results of
universal fuzzy controllers for a large class of nonlinear systems.
Authors:
Chang-wook Han,
Jung-il Park,
Volume: 1, Page 396 Paper number 1088
Abstract:
This paper describes the application of simulated annealing to a random
signal-based learning. Simulated annealing is used to generate the
reinforcement signal of the random signal-based learning. The validity
of the proposed algorithm is confirmed by applying it to the control
of the inverted pendulum using fuzzy controller and finding the minimum
of the nonlinear function.
Authors:
Shaoyuan Li,
Yugeng Xi,
Volume: 1, Page 398 Paper number 114
Abstract:
Abstract This paper presented a satisfactory optimization algorithm
with fuzzy goals and fuzzy constraints under the framework of predictive
control, it allows for more flexible aggregation of the control objectives
than the usual weighting sum of squared errors. Compared to the standard
quadratic objective function, the designer has more freedom in specifying
the desired process behavior. The main idea of the satisfactory control
is to satisfy the multi-requirement of production with limited manipulated
degree of freedom, inducing the performance indexes optimization and
various soft and hard constraints. The importance for different requirements
is defined by decision-maker and guaranteed by the control algorithm,
to construct a man-machine cooperative control mode to make user satisfactory.
By defining the membership degree of the control objective and system
constraint, and using the fuzzy interference, the optimal control problem
with constraint, multi-objective multi-degree of freedom can be transferred
as a convex optimal problem, so as to utilize the efficient optimal
algorithm and guarantee the global optimal solution. More importantly,
we can increase the freedom degree of control by adjusting the relevant
membership degree parameters of control objective and system constraints.
The designer's experience of control objective and system constraint
can be utilized through the fuzzy inference of language variables,
thus can be get better understanding of effect for control performance.
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