Noise on the roll and general question

[PietroChioda]

Dear Peter,

I am using your library on a wearable robot I am developing. I don't really need the heading but only the rotation on the sagittal plane ( or on what should be parallel to it), therefore i am using the update no mag. This, in your convention and according to how the sensor is placed, is the pitch angle. Together with it, i got a high level of noise on the roll axis, can you anyhow explain you me why, and how i can tackle it?

Moreover, do you know on which algorithm of data fusion it is based on? I would say a gradient descent one, but maybe you can give me some more reference.

Best,

Pietro

[peterhinch]

For the algorithm see the first reference in section 6 of the doc: it's the Madgwick algorithm.

Noise rather depends on the sensor and its environment. It's hard to offer a general solution. Vibration can be an issue: I have had to use mechanical filtering to partially decouple the sensor from a vibration source. Gyros are quite sensitive. Some IMU's provide internal filtering: check the device and driver docs. The fusion code certainly doesn't add noise.