Electronic – In theory, is the position derived from accelerometer absolute

accelerometerposition;sensorvelocity

I recently found multiple research papers that say that in theory double integral of accelerometer data gives a position of the device. Does that refer to absolute position (like the one given by a GPS)? or for example starting position and then relative position to the starting position?Thank you for helping me clarify this.

Best Answer

In theory, is the position derived from accelerometer absolute?

Ok, so imagine you're a sensor. All you can sense is acceleration. You're an accelerometer.

Now you're at rest, or moving at a constant speed. You can't tell the difference, since Newton's laws don't allow that – an object at rest or in linear motion experiences no acceleration.

Obviously, since you might be moving (or not), you can't tell where you are, and whether you'll be at the same position in 10 seconds.

So, that answers your question. An accelerometer + signal processor can only tell the position relative to some starting position, and only if the starting speed is known.

Mathematically, you'd have to differentiate twice to go from position to acceleration. So you'd have to integrate twice to go back. Each integration step adds an unknown "offset" to your result.

I'm a bit surprised you didn't come up with either approach!