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Topic: Measuring weight distribution of feet (Read 172 times) previous topic - next topic

NCHacker

I'm interested in measuring the proportional weight distribution between a person's feet, as well as between the forefoot and rearfoot. I would like to use FSRs either inside, or under, each shoe. (NOT a mat or anything like the wii fit)

What type of FSR would be best to collect analogue data within this weight range for an average person?
Do I need each FSR to have a range of 0-200+ lbs (for body weight), or could I somehow use smaller range FSRs successfully?

Here's a picture of something similar...

Thanks!


jremington

#1
Jan 12, 2018, 03:40 am Last Edit: Jan 12, 2018, 03:47 am by jremington
I think you will just need to experiment to determine what range of FSRs to use, as only you know what weight range of people will be standing on the array, and how they will be standing. If they move, all bets are off.

FSRs are highly nonlinear, so it will be a major undertaking to calibrate an array of them to return meaningful values. Here is a guide.

wvmarle

From that guide:

Quote
Its force sensitivity is optimized for use in human touch control of electronic devices. FSRs are not a load cell or strain gauge, though they have similar properties. FSRs are not suitable for precision measurements.
Doesn't sound really compatible wit your project.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

NCHacker

Thanks for the input. but what about companies that are creating insoles like these?

https://www.youtube.com/watch?v=jMf4rZzO81g

https://youtu.be/faCKarCmkJM?t=24s

Maybe they aren't relying on them for precise weight measurements, but they claim to be able to make comparative relationships between feet.
It probably will take some experimenting. Maybe there are only a few major pressure "thresholds" that really need to be measured, as opposed to precise measures along a complete spectrum of pressure.

jremington

#4
Jan 12, 2018, 05:32 pm Last Edit: Jan 12, 2018, 05:34 pm by jremington
Quote
but they claim to be able to make comparative relationships between feet.
According to the guide, with careful calibration, accuracy of 5% is possible, but resolution is much better (0.5%).

This means that although the measurements are not very accurate, small differences can be compared.

NCHacker


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