| Summary: | 博士 === 國立成功大學 === 電機工程學系 === 86 === In this dissertaion , some new method together with interval
operation arithmetic and genetic algorithms(GAs) are proposed to
solve the problems:1) model conversion of uncertain linear
systems, 2) robust digital redesign of sampled-data uncertain
systems with input time delay and 3) non-conservativeindividual
bound and controller bound of linear quadratic (LQ) regulator of
uncertain linear systems. Based on the bilinear approximation
method, we induct one parameter for tuning the error bound
between the exact and approximate uncertain system matrices. The
bounds of the interval system matrices via the proposed
intervaltuning bilinear approximation method are narrower than
those of the existing interval bilinear and the interval pade
approximation methods. The resulting interval models (the
enclosing interval models) are able to tightly enclose the exact
uncertain models. Also the approcximate discrete-time interval
solution is able to tightly enclose the exact interval solution
of the continuous-time uncertain state-space equation. Based
on the law of mean, the tuning bilinear method and the interval
arithmetic operation, we propose two methods for determining the
robust digital control law from the continuous-time uncertain
system with input time delay so that the resulting dynamic
states of the digitally controlledsampled-data uncertain system
are able to closely match those of the originalcontinuous-time
well-designed uncertain system. Whereas, due to the nature of
the interval arithmetic and the inherent conservativeness of
interval arithmetic operations, we present a new method together
with genetic algorithmsto solve the conservativeness problem.
Meanwhile, when the system state is notavailable, a discrete-
time observer is built based on the original continuous-time
observer with input time delay and predictor such that the
estimated states of the redesigned discrete-time observer match
those of the originalcontinuous-time observer with input time
delay at the sampling instants. We also use the property of
global search of genetic algorithm to calculate theindividual
eigenvalue bound and controller bound of the LQ regulator for
uncertain linear systems. The proposed methods will be helpful
for 1)analysis and synthesis of uncertain systems,
2)implememtation of hybrid control of sampled-data uncertain
systems with input time delay and 3) improving the direct
digitalcontroller design which only considers the system
behavior at sampling instants(not inter-sampling behavior). Some
illustrative examples are included to demonstate the
effectiveness of the proposed methods
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