some issues with imufusion settings and other questions

[pier098]

Hello,

I'm using your code to plot a 3D figure of gait tracked with my Arduino MKR IMU shield (BNO055), but I'm encountering some problems. In particular, I believe that the plotted position (in meters) does not match reality.

First of all, I collected 10Hz data for over 60 minutes without filtering the data in my Arduino code. Do I need to filter the data?

The IMU was upside-down, so the z-axis was pointing downwards. I set the NED convention, but do I need to multiply the acceleration by -1?

These are my imufusion settings:
`
``ahrs.settings = imufusion.Settings(imufusion.CONVENTION_NED, 0.8, 2000, 20, 10, 1 * sample_rate)```

And I modified the acceleration threshold as follows:

`is_moving[i] = numpy.sqrt(acceleration[i].dot(acceleration[i])) > 0.55

and the margin :

margin = int(0.1 * sample_rate)

Could you please tell me if I have set the parameters correctly?

Thank you.

[x-io Technologies]

"Do I need to filter the data?"
No

"do I need to multiply the acceleration by -1"
No

"Could you please tell me if I have set the parameters correctly?"
The original parameters already work well for the example data and should work for any data of sufficient quality to be used in this application.

I suggest you increase your sample rate to 100 Hz and start by logging just a few steps in a straight line. You may also find it useful to look through closed issues to see what other people have shared when using this code.

[pier098]

Thank you so much for your answer !

Does your filter work well for my purpose if I only use the IMU (i.e. 3D visualizing of position for a long time) ? I'm asking because in your PhD thesis, it's written that it could be used with cheap sensors and it works well. However, I've read a closed issue where you advised integrating it with GNSS

[x-io Technologies]

I expect you will get very poor results with a sample rate of 10 Hz.

[Susovan Patra]

Thank you so much for your answer !

Does your filter work well for my purpose if I only use the IMU (i.e. 3D visualizing of position for a long time) ? I'm asking because in your PhD thesis, it's written that it could be used with cheap sensors and it works well. However, I've read a closed issue where you advised integrating it with GNSS

His man,,, is it working for you??