Project Title:

Fast-Convergent Adaptive Noise Control System

AI Signal Research, Inc.
904 Bob Wallace Ave., Suite 211
Huntsville, AL 35801

93-1  12.13 0959    __      AMOUNT REQUESTED $69,904

Fast-Convergent Adaptive Noise Control System

Abstract:

The minimization of noise is of primary importance in optimizing
system performance. Active noise cancellation is one of the most
promising concepts for achieving noise reduction. This cancellation
is generally obtained by means of some type of an adaptive filter.
The key component of such a filter is the search algorithm
(typically least meansquared) by means of which the filter adapts
its coefficients to produce the desired "antinoise". Rapid
convergence, combined with stability and realistic system
simulation, are the most important performance characteristics for
the algorithm. AI Signal Research proposes to develop a new
advanced filtering technique for active noise cancellation. The
proposed active noise controlled system will utilize our proven
high-performance Recursive Least Square (RLS) and fractional
calculus adaptive filtering techniques to provide accurate
prediction of the desired "antinoise" to achieve noise cancellation
through an active secondary source. The ultimate effectiveness of
this system will be attributed to its fast convergent ability to
optimally adjust its filter characteristic for signal prediction.
This high-performance adaptive filtering technology, proven in the
SSME program for signal enhancement and noise cancellation for
engine diagnostics, has a wide range of industrial application and
can be placed into a commercial product to service US industry.

Active noise control systems have strong commercial applications
for a wide range of industries, including noise reduction in
automobile mufflers, aircraft cabins and ventilator ducts. There is
a tremendous need in the manifacturing industry to provide better
hearing protection for their employees who are constantly exposed
to excessive noise. A noise suppression system would also provide
the ability to create more effective hearing aids.

Active Noise Control, Adaptive Filter, Fractional Calculus