Trying to play with the falldetection lib on a sensortile

larry fischer · ‎2017-10-05

Posted on October 06, 2017 at 02:43

HAL is initialized. clock is initialized. I can make HAL calls but MotionFD_Initialize hangs. No docs, no info. Anyone have *any* info about this? The init code is just looping happily...

Miroslav BATEK · ‎2017-10-06

Posted on October 06, 2017 at 09:35

Hello Larry,

please enable clock for CRC unit in the microcontroller, it is needed for the algorithm initialization.

larry fischer · ‎2017-10-09

Posted on October 10, 2017 at 00:43

Well, I switched HW to the board that the falldetection app was designed for (x-nucleo-iks01$2). Everything built and downloaded and runs. The unicleo gui connects happily. I can see lots of user messages streaming by - pressure, temp, hum, accel, gyro, magnetometer. My question is: How do I make it detect a fall? I have tried dropping it 2-4 feet, onto my lap, in a towel, etc. I never see the app detect a fall. Any guidance on this lib would be helpful...

Thx - Larry

Miroslav BATEK · ‎2017-10-10

Posted on October 10, 2017 at 09:32

Indeed, to simulate the fall can by quite tricky.

I will explain a method which work for us:

- Wrap the board into some foam to avoid a damage when the board hit the ground

- Hold the board in vertical position (USB connector down)

- Drop the board

- Let the board still on the ground for a while

To evaluate the impact as man fall the altitude must change about ~80cm, the impact should be higher than 3-4g and the board must remain still after the impact.

Here is one example of fall detection:

larry fischer · ‎2017-10-10

Posted on October 10, 2017 at 16:23

Thank you for the detailed response. I will try all of this.

Is there a way to tune this algorithm such that it is more sensitive?

Thank you again,

Larry

Miroslav BATEK · ‎2017-10-10

Posted on October 10, 2017 at 16:32

It is not possible to tune the algorithm so far, the parameter are hard coded, but the parameter were trained on data sets captured during real man fall so it should work well.

larry fischer · ‎2017-10-11

Posted on October 11, 2017 at 17:04

Hmm. Wrapped it in bubble wrap. Dropped it from 4 feet to ground. Ive watched the user events, as well as looking at the fall detect screen. Ive also simply put it in debug mode from workbench, and waited to see the falldetect change state. Have yet to see it trigger. Any thing I have to do?

Miroslav BATEK · ‎2017-10-13

Posted on October 13, 2017 at 14:11

You can have a look at this

https://youtu.be/8ewIRzJ9pxg

showing our test.

I would be also good to record the acceleration and pressure and check them offline.