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Use 3-Axis Accelerometer to calculate theta?

asked 2012-02-20 22:17:27 -0500

Cav gravatar image

Hi,

is it possible to use a 3-Axis Accelerometer to estimate theta for the odometry (on a car-like robot, without a gyroscope)?

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answered 2012-02-20 22:25:19 -0500

You mean the yaw angle? No, you can't do that with accelerometers, as they measure linear acceleration, not angular rates like gyroscopes do (The angular rate has to be integrated to get an angle estimate in that case).

Using multiple highly accurate accelerometers placed on different parts of the vehicle one could in theory estimate the angular rate, but that's irrelevant here I guess.

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Yes, that's what I meant. Thanks!

Cav gravatar image Cav  ( 2012-02-20 22:27:12 -0500 )edit
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answered 2013-03-22 20:03:31 -0500

McMurdo gravatar image

Suppose I place the accelerometer at an offset from the centre of rotation. Then it would make a circular arc about the centre of the vehicle when the vehicle rotates purely. In that case, measuring X-acceleration and Y-accelerations, and using a kinematic model, can I not see where the accelerometer has gone with respect to the centre of the robot? If I can get that, then I should also be able to get 'theta' right?

Please correct me if I am wrong.image description

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Yes, this is possible in principle (provided one has very high accuracy accelerometers like those in tactical or navigation grade INS systems). From a practical POV, this likely will not work due to the noise characteristics of typical MEMS accelerometers, though.

Stefan Kohlbrecher gravatar image Stefan Kohlbrecher  ( 2013-03-23 00:00:15 -0500 )edit

How do I use the single axis accelerometer (one in the single axis IMU) to measure linear velocity (and hence linear distance covered)

McMurdo gravatar image McMurdo  ( 2013-03-23 22:02:45 -0500 )edit

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Asked: 2012-02-20 22:17:27 -0500

Seen: 1,710 times

Last updated: Mar 22 '13