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iosmatlabpositionaccelerometerkalman-filter
chintan s
chintan s

Reputation: 6488

Position estimation for iOS using accelerometer

In iOS, it is easy to access Linear Acceleration which is equal to subtracting Gravity from Raw acceleration.

I am trying to estimate position by double integrating Linear Acceleration. For that I recorded the data by keeping the phone steady on table.

Then I did double integration in Matlab using cumtrapz but when I plot the position it grows with time.

What am I doing wrong? I was expecting that the position should be 0.

Upvotes: 1

Views: 1382

Answers (2)

omkarvijay
omkarvijay

Reputation: 101

There would always been biasing errors from the sensors which can grow with time while integration. Can you calculate the drift of sensor when the device is at rest?. And then try to take the mean of the drift and subtract it from the input so that sensor shows 0 at rest, Then try to double integrate it

Upvotes: 0

Duncan C
Duncan C

Reputation: 131418

From what I've read this is too error-prone to be useful. Accelerometer based position calculations are subject to small drift errors, which accumulate over time. (If the phone is traveling at 100 kph constant velocity when your app first launches, you can't tell.) All you can measure is acceleration.

Upvotes: 1

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