team acoustic beamformer
DESCRIPTION
Midway Design Review. Team Acoustic Beamformer. 11/25/2013. Team Acoustic Beamformer. Name. Jimmy Danis EE. Nick Driscoll EE. Rebecca McFarland CSE. John Shattuck EE. Project Goal. Objective: scan and localize a single person’s - PowerPoint PPT PresentationTRANSCRIPT
1Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Team Acoustic Beamformer
Midway Design Review
11/25/2013
2Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Team Acoustic Beamformer
Nick DriscollEE
Rebecca McFarlandCSE
John ShattuckEE
Jimmy DanisEE
Name
3Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Project Goal• Objective: scan and localize a single person’s voice among outside conversation and background noise in real time• Primary Use: conference rooms (teleconferences)• Secondary Uses: small lecture halls, security
•Other Moral Implications:
• Help increase conference/lecture productivity
• Can help the hard of hearing
• Could act as an eavesdropping device
4Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Specifications
5Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Updated Block Diagram
6Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
7Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
8Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Narrowing the Frequency Range
0 2000 4000 6000 8000 10000 120000
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|H
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• Look at Phonetic Vowels• Have distinct peaks in magnitude
across the frequency range known as “formants”
• First is highest in magnitude, provides a low frequency window
Phonetic Vowel “ᵢ”
9Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
10Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Current System Specifications• Mic spacing: 24cm
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F=450Hz
F=680Hz
BW=52°
BW=34°BW=50°BW=50°
BW=61°BW=61°
11Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Design Flaws to Be Addressed
• May not be a worry in considering the magnitudes within our beam
12Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
13Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
A/D Choice
14Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
MicrophonesSelected different mics – CMA-4544PF Electret Condenser Mic from CUI Inc.•Better sensitivity (-44 dB+/-2 dB)•Better Voltage Rating (3-10 V)•Wider frequency response (20 Hz- 20kHz)•Easier form factor to work with•Previous mics needed PCBs•These plug right into breadboard•Faster, easier, better specs•Also Omni-Directional
15Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Deliverable: Mics into A/D
• Hook up 2 microphones• Have those feed into A/D• Show that 2 microphone inputs can be recovered on the
computer
• DEMO
16Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Software
• Custom real-time software• Microsoft Windows application• Built in C++• Using open source Aquila DSP library to do DSP
calculations• Investigating whether we want a matrix math library as
well• Currently using Microsoft Windows API to play back sound• Could also use open source API (CoreAudio) to play back
sound so that the code is platform agnostic
17Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Deliverable: Software
• Get overall framework together• Start hooking up pieces by showing we can load a WAV
file and play it back• Exercises playback code
•DEMO
18Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Deliverable: MATLAB Simulations
• Taking 2 inputs into MATLAB and beamforming• Used 2 computer mics to record test signals
19Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Individual Microphone Inputs
20Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Sum of Microphone Inputs
21Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Sum of Delayed Mic Inputs
22Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Unfiltered DFT of Inputs
23Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Filtered DFT of Inputs
24Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Cost Analysis
Items Purchased So Far
Remaining to purchase: PCBs
Item Purchased
Num. Purchased
Unit Price Total Cost
A->D Converter 1 $165 $165.00
MEMS Mics 3 $3 $9.12
Electret Mics 12 $.75 $14.20
Spent So Far $188.32
25Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
CDR Deliverables
• Nick:• Optimize microphone amplifiers• Increase to 8 microphone input channels to A/D• Rebecca:• Take A/D as input into software• Save out wave file• Jimmy:• Design Band Pass Filter• Spherical Wave Algorithm• John:• Spherical Wave Calculations• Team:• End-to-End System (take input from multiple mics, pass through
A/D to computer, perform beamforming functions on inputs)
26Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
FPR Deliverables
• Nick:• PCB Fabrication for Amplifiers/Microphone Combinations for all 8
inputs• Rebecca:• Implement scanning, Final Real-Time Analysis• Jimmy:• Scanning algorithm in MATLAB, Widen frequency Range• John:• Widen frequency range (Algorithms)• Scanning technique algorithms• Team:• End-to-End system, beamforming performed on 8 microphone
inputs with a polished, professional presentation
27Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Schedule for 2014
28Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Questions
29Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Questions
30Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Microphones• Analog Device MEMS Microphone
• Omnidirectional
• Analog output
• Frequency range: 100 Hz – 15 kHz
• Sensitivity -42 dB +/- 3 db @ 94 dB SPL
• S/N Ratio 62 dB
31Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink
Near-Field Beam Widths