| Linearization
· Need
Linear-Time Invariant Models for Applying Modern Control Theory.
· Most
Practical Control Problems are Nonlinear.
· Taylor
Series Linearization Provides a Direct Way to Derive Linear Approximation
to a Nonlinear System.
· A Given
Nonlinear System:
,
Define a Nominal Condition:
Such that

and:
Expand the Right
Hand Sides of the F(.,.), G(.,.)
in a Multi-Dimensional Taylor Series About
the Nominal Condition To Yield:

Using the Fact:
, at any Given
Nominal Value ,
the Linearized System Dynamics is Given By:

Where A, B,
C, D are Matrices of Partial Derivatives (Jacobian
Matrix) Evaluated at the Nominal Values:

Brook
Taylor (1685-1731)
English Mathematician. Taylor published a definitive work on the
Mathematical theory of perspective and obtained major mathematical
results about vibrations of strings. He also authored an unpublished
work, On Musick, which was intended to be a joint paper with Isaac
Newton. Taylor's Most Productive period was from 1714 to 1719, during
which time he wrote on a wide range of subjects including Magnetism,
capillary action, thermometers, perspective, and calculus.Taylor's
writing style was so terse and hard to understand that he seldom
received credit for many of his innovations.
Carl
Gustav Jacob Jacobi ( 1805 - 1851)
Jacobi was a Professor
at the University of Konigsberg from 1826 to 1843. He was the son
of a Berlin Banker. He spent some time in Italy trying to recover
his health, and ended his carrier as a professor at the University
of Berlin, dying at the age of 46. He was witty and liberal thinker,
an inspiring teacher, and a scientist whose enormous energy and
clarity of thought left few branches of mathematics untouched. Sylvester
(English Mathematician, Poet, contemporary and collaborator of Arthur
Cayley, spent most of his life in the Acturial Trade, also taught
at the University of Virginia, and Johns Hopkins University) coined
the name "Jacobian" to the functional determinant in order
to pay respect to Jacobi's work on Algebra and Elimination Theory.
The most popular work of Jacobi was his lecture series on dynamics.
He also obtained important results on the "Sufficiant Conditions"
for a minimum, which are still in use by the practitioners of Optimal
Control Theory.
|