THE AMAZING ACCELEROMETER

Single Unit (about $4)

Which way’s up?

http://www.youtube.com/watch?v=KZVgKu6v808#t=246

Basis of the Technology

Another view

Biomedical

Automotive

Guidance/Navigation

Structural Health Monitoring

Sports Medicine: Concussions

FitBit and Nike Fuel

Accelerometer Design: Frequency Response

Very low r values = good design

Accelerometer Design: Phase Lag

-f

The Problem with Phase Lag

If not designed properly, phase lag causes the measured signal to deviate from the actual acceleration. (Above example would be for a BAD design.). Ideally, you want to design for zero phase distortion.

Where does damping come from?

c

Dynamic viscosity of air

Squeeze Film Damping: Thin film of air interacts with silicon masses in motion