Transcript Active Noise Control System

ANC-PRO (#22)
ACTIVE NOISE CONTROL IN
HIGH STRESS ENVIRONMENTS
Greg White
Tyler Mose
Logan Jennyc
Mike Krawczyk
Jon Samuelson
Advisor: Norm Bartley
THE PROBLEM
Machinery is used extensively in today's society
 Long term exposer can lead to hearing problems
 Many environments contain noise pollution

Image obtained from
http://tracyroberts.ca/?p=344
Image obtained from
http://www.automation-drive.com/cncmachine-shop
Image obtained from
http://www.globaltvedmonton.com/Westjet+plane+
makes+emergency+landing/2396494/story.html
TRADITIONAL SILENCERS
Can be expensive to
build, maintain and
operate
 Susceptible to high levels
of heat, compressed gases
and acid

Image Provided Courtesy of Noise Solutions Inc.
Image provided courtesy of Noise Solutions Inc.
Image obtained from http://www.sr20-forum.com/general-sr20/1821-quest-quiet-muffler-13.html
THE SOLUTION
Active Noise Control System
 The idea behind ANC is the application of a 180 o
delayed sine wave to an incident wave.
 The out of phase waves undergo destructive
interference, and are effectively cancelled out.

Obtained from: Representing a Radio Wave With a Sinusoid by Peter Wittenberg
http://radarproblems.com/chapters/ch05.dir/ch05pr.dir/c05p1.dir/c05p1.htm

Mike, add your shit
HARDWARE CHALLENGES
Fitting an end cap to the propagation tube is
deceptively difficult
 Special microphone required to pick up low
frequency tones



Most microphones have too small diaphragm
Hardware versions of pink noise generator and
BPF require amplification
HARDWARE CHALLENGES (2)
Microphone input on MacBook does not work
with unamplified source
 USB sound card only supports mono input


New assumption that the frequency would be
captured using an alternate method
e.g. Optical encoder on engine fly wheel
SOFTWARE CHALLENGES

NONE, because I AM
AWESOME
!!!
SOFTWARE CHALLENGES (2)
Just kidding - about the NONE
 Setting up the FFT algorithm to run as fast as
possible
 Clicking in cancellation signal due to constant
phase shift
 Reducing phase shift jumps as the incident power
is reduced

SOFTWARE CHALLENGES (3)

Large phase discontinuity between maximum
and minimum delay points

May never find peak cancellation phase if both sides
of discontinuity are on the downslope
CONCLUSION
Image courtesy of http://ragebot.com/p=5153
TECHNICAL ASPECTS
Working Prototype
 Hit all target specs except one
 Met all deadlines thus far
 Maintained high standard of quality

CONCLUSION(2)
Academic advisor
 Demonstrated on Thursday March 31st
 Norm Bartley satisfied with prototype
Industry advisor
 Andrew Faszer was too busy to come for a
demonstration
 Andrew satisfied with prototype
Group
 Everyone performed according to their roles
NEXT STEPS
Capstone Design Fair
 Model is ready
 Requested power supply and extra space
Final Report
 All sections have been assigned
 Working on initial draft
Faulty Marks
 Team Evaluation

FUTURE WORK
This project successfully demonstrates the proof
of concept
 Next step would be to ramp it up to a real world
system
 Design and build control system housing
structure
 Design and build chip for control program
 Use electronics that are resilient to stresses
found in an engine
 Test noise suppression Vs. actual engine sounds
