Comprehensive Design Review

Team Vibraid

March 2014

VibraidMichael Balanov(Mike) EE

Spyridon Baltsavias(Spiros) EE

Reona Otsuka(Leo) EE

Andrew Woo(Andy) EE

Previous Block Diagram

44

44 4 8

switch signal

variable resistance

variable resistance

Revised Block Diagram

44

4 4 4 4

switch signal

variable resistance

variable resistance

Demo Outline

• 4 way directionality amplitude comparison

• Microphone inputs, processing and output functioning correctly.

• Filter not yet integrated but functional

FPR Goal - Revised RequirementsSpecification Value

Max detection radius for 50dB-120dB sound within frequency range

3m (10ft) , 90% of times

• How to meet spec?

• Amplitude comparison algorithm modifications

• Time delay estimation between input sound signals

Determining Time delay

• Use cross-correlation of pair of signals

• Find argmax, corresponding to delay (in samples) between signals

FPR Goal - Revised RequirementsSpecification Value

Max detection radius for 50dB-120dB sound within frequency range

3m (10ft) , 90% of times

Frequency detection range 100Hz to 10kHz

• Sampling frequency?

• 10kHz ADC on Arduino

• 4 inputs -> 10k/4 = 2.5kHz each

• 1.25kHz maximum signal

• Important sound frequencies

• Baby cry: 300 – 440 Hz

• Car Horn: 400 – 500 Hz

• Alarms and sirens: 1 - 3 kHz

FPR Goal - Revised RequirementsSpecification Value

Max detection radius for 50dB-120dB sound within frequency range

3m (10ft) , 90% of times

Frequency detection range 100Hz to 10kHz

Belt circumference 75-105cm (small-large)

Belt width <10cm

Belt thickness <5cm

Product weight <1kg

Detection directionality 4 directions

Vibration response time <o.5sec

Vibration directionality Vibration to alert user in one quadrant

Vibration to corresponding detection 99% of times

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)

Q&A

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

Pros and Cons of Design

• Pros

• Intuitive polar representation

• Horizontal orientation

• Adjustable

• Cons

• User may need to tuck in their shirt

• Hand/clothing obstruction

Sprectrum of potential sound sources

• Baby cry: 300 – 440 Hz

• Car Horn: 400 – 500 Hz

• Alarms and sirens: 1 - 3 kHz

https://www.google.com/search?q=frequency+range+of+alarams&oq =frequency+range+of+alarams&aqs=chrome..69i57.5644j0j1&sourceid= chrome&espv=210&es_sm=122&ie=UTF-8#q=frequency+range+of+alarms

http://en.wikipedia.org/wiki/Vehicle_horn

http://www.livescience.com/38298-cry-analyzer-could-indicate-babies-health.html

D

d

Gantt chart