Preface - Wiley

bustlingdivisionElectronics - Devices

Nov 15, 2013 (3 years and 4 months ago)

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Preface
Most of the recent research activities in active,hybrid,and semi-active
structural control have been focused on a variety of control algorithms based
on several control design criteria.Although a number of active,hybrid,and
semi-active control systems have been implemented to control the vibration
of buildings and towers,and many experimental studies have been conducted,
the necessary knowledge needed for implementation is still not sufficient to
prepare general guidelines for active control system design and installation.
Furthermore,the whole implementation process,which requires integration
of research results from diverse interdisciplinary areas,has not been well
addressed.
The purpose of this handbook is to develop and document the knowl-
edge needed to implement successfully an active,hybrid,or semi-active
control systemto a structure for safeguarding it against environmental forces
such as wind or earthquakes.Important issues involved in the integrated
implementation of active control systems are addressed in this book.The
major requirements of the control hardware are first addressed.Some spe-
cific equipment needs are identified in a specific case study to fulfill the
requirements of implementation.
The implicit issues between theoretical development and actual implemen-
tation of active controlled systems are then examined.The basic knowledge
needed to handle digital data discretized from analog measurements and
some important factors such as the transformation fromtheoretical simulated
values to practical signals or the effects of quantization are introduced and
methods to minimize these effects are discussed.The compatibility between
control hardware and software of the integrated system is also evaluated in
detail.
A digital control console that contains a dedicated personal computer (PC)
with an independent digital signal processor (DSP) is used to develop robust
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PREFACE
control algorithms and modularity in implementation.The most attractive
feature of a DSP-based digital control system is its independence and speed
of processing the signal acquisition and control processes.It significantly
reduces the time required to provide specified control commands and also
enhances the capability of applicable control algorithms such as nonlinear
control or adaptive control.
Important hardware and software safety features are also identified in
order to eliminate many of the common problems that may occur in practical
implementation of a sophisticated hardware system.It is shown that some
custom-designed electronic boards can be built to satisfy these requirements.
Additional issues,such as discretization in time,output feedback,sensor
inaccuracies,time delays,measurement noises,and even real-time integration
of the measured signals,are considered in the modular functions of the DSP
system.The modular design approach allows straightforward inclusion of
their effects at appropriate times.
Finally,a PC-based system simulator which simulates the real-time
response of a structure and control hardware is described in order to verify
implementation procedures and fail-safe protection functions of the con-
trol console.This simulator also provides a pre-implementation testing base
to verify the accuracy of system identification results.Due to the digital
nature of the computer-controlled simulation system,a discrete-time model
is developed and used to verify control effects that are designed based on
the continuous-time system.The real-time structural simulator is also used
to conduct reliability analysis of the integrated system with parameter uncer-
tainty and measurement noise.