<< Chapter < Page Chapter >> Page >
This module describes our testing setup and the results we obtained.

Testing and results:

Our testing array consisted of four microphones borrowed from the electrical engineering lab, four audio to USB converters, and a USB hub that was then connected to the computer running the program. We tested two different setups (positions) for the array of microphones, a square and a parallelogram. Again, we simulated the rifle impulse with a hand clap. Our results are as follows:

First Array: Square

Microphones at (0, 0, 0), (0, 2, 0), (2, 0, 0), and (2, 2, 0)

Position (X,Y,Z) Results Tau (1,2,3,4)
(0,0,0) (-651.2859, -313.7830, 0) 0 0.0118 0.0103 -0.2602
(0,0,0) ( -199.8994, 272.4750, 0) 0 0.0064 -0.0028 0.4928
(0.5,-7,0) (1.0e+003*-1.1840, 1.0e+003*0.0451, 0) 0 0.0030 -0.0117 0.4828
(0.5,-7,0) (1.0e+003*3.8188, 1.0e+003*1.3335, 0) 0 0.0218 0.0303 0.4928
(8,1,0) ( 1.0e+004*1.1917, 1.0e+004*0.0959, 0) 0 0.0018 0.1032 0.4828
(8,1,0) (1.0e+003*7.0765, 1.0e+003*0.0780, 0) 0 0.0118 -0.0726 -0.4460
(1.5,19,0) (1.0e+004*-1.0404, 1.0e+004*-0.1080, 0) 0 0.0118 0.1132 -0.4460
(1.5,19,0) ( 1.0e+003*2.4049, 1.0e+003* 0.7235, 0) 0 0.0118 0.0203 0.4828
(-3,2,0) (1.0e+003*3.7463, 1.0e+003* 1.3085, 0) 0 0.0218 0.0303 0.4828
(-3,2,0) ( 1.0e+004*-1.8326, 1.0e+004*0.1534, 0) 0 0.0118 0.2061 -0.4460
(-4,-2,0) ( 1.0e+003*-1.0406, 1.0e+003*-0.1446, 0) 0 0.0018 0.0103 -0.4560
(-4,-2,0) ( 1.0e+003*3.5954, 1.0e+003*0.8343, 0) 0 0.0118 0.0303 0.4928

Second Array: Parallelogram

Microphones at (0, 0, 0), (-0.5, 7, 0), (3, -1, 0), (3.5, 4, 0)

Position (X,Y,Z) Results Tau (1,2,3,4)
(0,0,0) (-201.4001, 63.0702, 0) 0 -0.0911 0.0096 0.0068
(0,0,0) ( 2.7784, -7.2170, 0) 0 -0.0070 0.0081 -0.0038
(0.5,-7,0) (1.0e+003* 0.7510, 1.0e+003*-3.3145, 0) 0 -0.0711 0.0203 0.4828
(0.5,-7,0) (1.0e+004*1.5821, 1.0e+004*-0.2474, 0) 0 0.0218 0.1232 0.4828
(8,1,0) (-50.6356, -11.9636, 0) 0 0.0018 -0.0726 -0.0745
(8,1,0) (858.3622, 88.1823, 0) 0 0.0118 -0.0726 -0.0745
(1.5,19,0) (-40.0023, -925.3581, 0) 0 -0.0711 0.0303 0.1213
(1.5,19,0) ( 1.0e+003*2.6500, 1.0e+003*1.2213, 0) 0 0.0218 0.0203 0.4928
(-3,2,0) (1.0e+003*2.4049, 1.0e+003*0.7235, 0) 0 0.0118 0.0203 0.4828
(-3,2,0) (1.0e+004*-1.2287, 1.0e+004*0.1966, 0) 0 0.0218 0.1232 0.3071
(-4,-2,0) (1.0e+003*-5.6438, 1.0e+003*-0.0804, 0) 0 0.0118 -0.0726 -0.3531
(-4,-2,0) (1.0e+003*1.7925, 1.0e+003*0.2009, 0) 0 0.0018 0.0203 0.3899

As can be seen above in both of our test setups the scale (originally measured in feet) was off by a large magnitude. The second setup, the parallelogram did resulted in less of an error in scale, but there was still a large discrepancy. Although the scale was off, the ratio of X and Y (shown by the position of the clap) was correct even if the magnitude was off.

Besides discrepancies in scale we did have issues with our results for tau, which represented the time delay of the audio reaching the various microphones. We were unable to synchronize the microphones and get them all to begin recording simultaneously. We did try calibrating them but the recording delays of the microphones changed each time so our calibration was an average, and therefore not exact. This meant that the microphones had a delay (of about a tenth of a second) between the first one beginning to record to the last one. In some cases, the microphone that should have recorded the sound first began recording before the other microphones, making it appear that that microphone heard the sound last. These issues overall led to skewed results for the various values of tau in our testing. Because the results depended so much on the time delay, none of our results gave the correct location of the origin of the sound. We did however manage to get the general direction of the sound correct about 50% of the time.

The results that we produced were far from what we expected or desired. Although we did manage to get the general direction in about half the cases we were nowhere near determining the exact position. The problem was most likely caused by the inability to the properly calibrate or synchronize the recording of the microphones. There are a variety of ways that could have solved this problem such as an external trigger that started the microphones at the same time or running the microphones on four different programs that fed into one other program that then analyzed the data. Microphone sensitivity could also possibly improve the results.

Overall, our results do determine the general direction of the sound and prove that multilateration can be used to help pinpoint location.

Questions & Answers

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Elec 301 projects fall 2011. OpenStax CNX. Jun 18, 2012 Download for free at http://cnx.org/content/col11431/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Elec 301 projects fall 2011' conversation and receive update notifications?