Sound Localization PART 2

Ali Javed, Josh Manuel, Brunet Breaux, Michael Browning

Milestone 1 to do list:

• Build Sample Space• Make Sample Point Database• Interface Video Recording Camera code• Adjust RLS filter• Optimize/Test Program

Sample Space

• Test Area• 10’ x 10’ x 8’

• Interior grid• 2’ x 2’ x 2’

• Sound source stand• 8’ Height, 2’ Increments • Mobile

• Microphones• 4 at different Corners

Sample Point Database

• We were able to build it.• The data we collected wasn’t consistent

enough for us to localize sound.

Problems with our original sample point database

• Sound source used• Room noise threshold • Consistency of hardware

measurements

Methods for Improving Onset Results

• Calibrate room noise level for each mic individually

• Find more reliable sound source to create database

• Test different room noise threshold multipliers

• Multilateration

Video Recording

• Interface Video Recording Camera code– Initializing camera

• Adaptor, Device id, Format and Resolution

– Set Recording length• ‘Bufferlength’ Variable

– AviObject• Name, Compression, FPS, and Quality

ImFrame Loop

– Camera Trigger• vid.framesPerTrigger=X

– aviObject = close(aviOblect);

RLS Filter

• Last time– Not filtering properly– Too slow

• Now– Filtering well

• Improves sound to noise ratio by about 4 times• Was doing this before

– Plotting method was erroneous, not filter

– Still slow• Even with minimal sample comparison length

Euclidean Distance Code

Euclidean Distance Code

MultilaterationTime Difference of Arrival (TDOA)

• Simple trigonometric difference comparison calculation

• By solving a system of three equations each using a different mic comparison for d, e.g. absolute value of onset A – onset B, X Y and Z coordinates can be calculated

MultilaterationTime Difference of Arrival (TDOA)

• Pros– Does not rely on database– Margin of error can be calculated– Effective closer to center of the test space

• Cons– Ineffective on edges of test space– Must pick ‘base’ mic used in each comparison

• Possible fixes– Move mics further from corners– Average values of four different system solutions

• One for each ‘base’ mic option

Future Goals:

• Finalize Video code• Implement GUI• Optimize signal collection for accurate

localization• Determine minimum sound source

decibel level and accuracy of final product

• Make it work and look good doing it