I am not able to find hover_freq value in the mission planner

Drone · July 31, 2021, 6:21am

Hello everyone!!

I am working on dynamic notch flter configuration. For that I need the following two values,
hover motor frequency hover_freq and thrust value hover_thrust

I got the hover_trust value but not the hover_freq value.

Please let me know where I can find the value of hover_freq.

andyp1per · July 31, 2021, 7:39am

It’s the value for the largest peak that you read off the FFT graph

Drone · July 31, 2021, 8:00am

There are two graphs.

FFT ACCO
FFT GYRO
Out these which one should be consider for a higher value?
Screenshot (16)1366×768 51.5 KB

Please see the picture and point out the value.

andyp1per · July 31, 2021, 8:06am

The gyro graph, although often the peaks are at the same frequency

Drone · July 31, 2021, 8:09am

For me
Hover_freq is 96.98. Is this wright?

Drone · July 31, 2021, 8:17am

hover_thrust is nothing but MOT_THST_HOVER. Am I wright?

amilcarlucas · July 31, 2021, 9:05am

yes, 100Hz is the correct frequency. You want the frequency (x-axis) not the amplitude (y-axis)

amilcarlucas · July 31, 2021, 9:07am

yes, MOT_THST_HOVER if MOT_THST_LEARN is set to 2.

This is clearly explained in the documentation. Did you read the documentation?

Drone · July 31, 2021, 9:22am

You mean I have to take the X- axis value only to update the following configuration write?

Harmonic Notch Configuration for Throttle Based Mode

Set INS_HNTCH_ENABLE = 1 to enable the harmonic notch
Set INS_HNTCH_REF = hover_thrust to set the harmonic notch reference value
Set INS_HNTCH_FREQ = hover_freq to set the harmonic notch reference frequency
Set INS_HNTCH_BW = hover_freq / 2 to set the harmonic notch bandwidth

Drone · July 31, 2021, 9:25am

I read it. My question is
hover_thrust and [MOT_THST_HOVER] are the same parameter or different one?

Luciano_Andreani · July 31, 2021, 10:43am

For Drone

Hello,
tell me where you see this so precise value

"For me
Hover_freq is 96.98 "

I am also a beginner and I have a lot to learn
Thank you

Drone · July 31, 2021, 11:21am

From this graph. FFT GYRO Amplittude value.

amilcarlucas · July 31, 2021, 12:20pm

Not the amplitude value!!! The Frequency (Hz) of the maximum amplitude value!

Yes, hover_thrust is equal to [MOT_THST_HOVER] if [MOT_THRST_LEARN] = 2

Rohan · July 31, 2021, 1:07pm

Open Log , from mission planner then go CTUN section, ThH (throttle hovering value) you can find over there, and ThO (throttle output) also.

Drone · July 31, 2021, 1:20pm

Hi Rohan
In my log am not getting that CTUN section. Buy anyway I got the hover thrust from full parameters list.

Derek · July 31, 2021, 2:09pm

CTUN might not be enabled in the parameter LOG_BITMASK

You can calculate the bitmask to enable it in full parameter list but I find it easier to use the checkboxes in the normal/advanced parameters tabs

Drone · July 31, 2021, 2:29pm

Thanks for the response.I will check that.

Drone · July 31, 2021, 6:55pm

So the hover_freq is 440hz corect? From the below picture.

amilcarlucas · July 31, 2021, 7:44pm

No!!! That is the Accelerometer (FFT ACC0 graph) max amplitude.

You want the gyro (FFT GYR0 graph) frequency (HZ) at gyro max amplitude. And that is around 100Hz, the corresponding amplitude also happens to be 100, but that is just a coincidence!

dkemxr · August 1, 2021, 12:04am

So you don’t understand an FFT graph plotting frequency on the X-axis vs amplitude on the Y and only the Gyro graph is relevant. No big deal. Set the frequency to 100hz, the Band width to 50Hz and the Reference = Mot_thst_hover.