Midway Design Review Team Vibraid November 2013. Vibraid Michael Balanov (Mike) EE Spyridon...
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Transcript of Midway Design Review Team Vibraid November 2013. Vibraid Michael Balanov (Mike) EE Spyridon...
Midway Design Review
Team Vibraid
November 2013
VibraidMichael Balanov(Mike) EE
Spyridon Baltsavias(Spiros) EE
Reona Otsuka(Leo) EE
Andrew Woo(Andy) EE
Assistive technology for the deaf community
• Fact: Over 5% of the world’s population – 360 million people – has disabling hearing loss
• Deaf/hard of hearing people have limited awareness of surroundings
• High demand but production of hearing aids meets only 10% of global need
• Currently deaf people have to use specific aids for different applications
• Expensive
• Impractical
Vibraid: Vibration + Hearing Aid
• Convert sound to vibration
• Research shows haptic feedback usefulness
• Lip-reading, frequency detection
• Alert user of impending danger/sound source
• Enable tactile sound localization
Physical Design
• Waist Belt
• Intuitive polar representation
• Horizontal orientation
• Relatively minimum obstruction
Requirements Table
Specification Value
Circumference 75-105cm (small-large)
Width <10cm
Thickness <2cm
Weight <1kg
Previous Block Diagram
Revised Block Diagram
• Main changes:
• No Arduino – hardware implementation
• Filtering
• No light output
44
4 4 4 8
switch signal
variable resistance
variable resistance
MDR Focus
MDR Deliverables
• PDR proposal: Sound to Vibration & Light
• Demo time!
• Additional Deliverables: progress towards 2-way directionality
• Input Block:
• Andy: Microphone requirement testing
• Spiros: Envelope Detector design
• Processing & Motor Block
• Mike: Comparator logic & motor activation
• Leo: Sensitivity logic & DC voltage testing
Input Block• Purpose:
• Record sufficient sound data
• Pass it on for processing in a format suitable for amplitude comparison
• Microphone characteristics:
• 4 omnidirectional microphones (Freetronics.com)
• Vendor provided frequency response: 60Hz to 15kHz
• 2 outputs
• AC audio voltage
• “SPL” output DC voltage proportional to amplitude
• Mics placed in 4 locations (right/0°, front/90°, left/180°, back/270°)
Requirements Table
Specification Value
Detection Directionality
4 directions
Detection frequency range
100Hz to 10kHz, 90% of time
Detection radius for 50dB-120dB sound within frequency range
>3m (10ft), 90% of time
Microphone Range Test (Voltages)• Procedure:
• Measure “SPL” voltage of noise
• Range: 0.00V-0.08V, depending on environment
• Measure “SPL” voltage of test-sound
• Computer-generated 440Hz tone
• Sound directed towards front of microphone
• Sound level from 3ft away: ~70dB (measured with dB meter application)
• Determine maximum range for which voltage>noise+0.1V
• Average Results:
• 10ft detection: yes
• 15ft detection: no
Microphone Frequency Response
0 2000 4000 6000 8000 10000 12000 140000
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
SPL Voltage Vs Frequency
Frequency (Hz)
SPL
Volt
age (
V)
Mic B
Mic A
Radius R
Microphone Sound Detection Test
(2 microphones)
15 in
Mic B
Mic A
Corresponding angle for each microphone
0/180
225/45
180/0
135/315
90/270
45/225
270/90
315/135
Degree relative to Mic A/Degree relative to Mic B
Mic SPL Voltage Reading for various angles
Mic #/Degree
0 45 90 135 180 225 270 315
1 0.33
1.49
2.82
1.36
0.88
1.40
1.01
1.39
2 1.61
1.47
2.23
1.83
1.30
0.85
1.41
1.31
3 1.22
1.52
2.87
1.47
1.06
1.52
1.34
1.28
4 1.52
1.52
2.42
1.60
0.83
0.53
1.21
0.88
Mic #/Degree
0 45 90 135 180 225 270 315
1 1.52
0.88
1.60
1.09
0.15
0.52
0.10
0.24
2 1.46
0.70
1.96
0.81
0.83
1.45
1.44
1.28
3 0.50
1.16
1.79
1.60
1.13
0.86
0.79
1.08
4 0.48
0.40
1.57
0.69
0.05
1.18
0.08
0.41
R = 10 inches
R = 15 inches
Mic 2
Mic 1
Example Mic comparison
1.22/0.83
1.52/1.52
1.06/1.52
1.47/0.88
2.87/1.21
1.52/0.53
1.34/2.42
1.28/1.60
Voltage output of Mic 1/Voltage output of Mic 2
Radius = 10 inches
(#) = Stronger Mic at given location
(2)
(1)
(1)
(1)
(1)
(1)/(2) (2)
(2)
Test Conclusion and Evaluation
• Inconsistency across each microphone
• Unexpected spikes/drops of voltage in some angles
• Microphones are not completely omni-directional
• No simple relationship between distance and sound amplitude
• Consider directional microphones
Input Block pt.2
• “SPL” output
Envelope Detector Design
Input – DC Block – Amplification
Amplification – Rectification– Smoothing
Processing Block• Purpose:
• Receive sensitivity knob input to determine if microphone input should be received
• Receive microphone output in order to compare amplitudes
• Determine quadrant of incoming sound
• Produce output signal with motor activation information to be read by Output Block
Requirements Table
Specification Value
Vibration Directionality
Simultaneous vibration in 2 adjacent locations
Vibration response time
<o.5sec
Processing Block Circuit
Comparator/Sensitivity Logic DC testing
Input 1 (V)
Input 2 (V)
Output (V)
0.02 0.02 -0.91
0.02 2.43 -0.91
0.02 4.91 -0.91
2.43 0.02 4.33
2.43 2.43 -0.91
2.43 4.91 -0.93
4.91 0.02 4.33
4.91 2.4 4.33
4.91 4.91 -0.92
Output Block• Purpose:
• Receives control signals from Processing block
• Activates motors in appropriate location
• Indicates relative sound amplitude
• Motor characteristics
• “Coin” vibration motors, used in cellphones
• Noticeable vibration on skin
• Small voltage rating
• 2 motors per key location (front, back, sides)
Requirements Table
Specification Value
Vibration Directionality
Simultaneous vibration in 2 adjacent locations
Vibration to corresponding detection
99% of times
Vibration response time
<o.5sec
Output Block Circuit
Input 1 (V) Input 2 (V) NAND output (V)
Inverter output (V)
-0.91 -0.91 4.75 0.01-0.91 4.33 4.83 0.014.33 -0.91 4.82 0.014.33 4.33 0.00 4.91
Interface Block• Purpose:
• Allow user customization for three features
• Microphone sensitivity
• Adjusts the threshold voltage for comparator block
• Frequency range detection
• Switches between 3 frequency filters and bypass
• Motor strength
• Modifies the motors strength according to user preference b
• Method
• Potientiometers for tunable voltage divider
• Switch to disconnect and reconnect to desired circuit
Requirements Table
Specification Value
Tunable sensitivity
Block-all till pass-all
Tunable frequency detection
4 modes: full range, 100Hz to 4kHz, 4kHz to 7kHz, 7kHz to 10kHz
Tunable motor strength
No vibration (0V) to Max supply (5V)
Output and Interface Potentiometers
Motor strengthMicrophone sensitivity
Summary of RequirementsSpecification Value
Belt circumference 75-105cm (small-large)
Belt width <10cm
Belt thickness <2cm
Product weight <1kg
Detection directionality 4 directions
Detection frequency range 100Hz to 10kHz, 90% of time
Detection radius for 50dB-120dB sound within frequency range
>3m (10ft), 90% of time
Vibration response time <o.5sec
Vibration directionality Simultaneous vibration in 2 adjacent locations
Vibration to corresponding detection 99% of times
Vibration response time <o.5sec
Tunable sensitivity Block-all till pass-all
Tunable frequency detection 4 modes: full range, 100Hz to 4kHz, 4kHz to 7kHz, 7kHz to 10kHz
Tunable motor strength No vibration (0V) to Max supply (5V)
Gantt chart
CDR Deliverables• Goal: Demonstrate 4-way detection and vibration directionality
• Correct quadrant determination
• Meet range, frequency specs
• Implement working user interface
• Prototype filter
• Implement levels of motor activation
• Portable power supply
Q&A
Power Specifications
Preliminary Cost Analysis
Pros and Cons of Design
• Pros
• Intuitive polar representation
• Horizontal orientation
• Adjustable
• Cons
• User may need to tuck in their shirt
• Hand/clothing obstruction
0 2 4 6 8 10 12 14 160
0.5
1
1.5
2
2.5
3
"SPL" Voltage vs. Distance
75dB voice, matching freq.
70dB tone, 440Hz
Distance (ft)
SPL
Volt
age (
V)