Altitude Hold and stability

Log Analysis -- deprecated Copter Logs -- deprecated
1

2017-02-01 00-17-18.bin (2.0 MB)

Hello all,

I need your help cause i already checked that all first flight check has been done but I have still 2 issues :
_Stability : in flight the copter is controllable but some oscillations happen many times ( no vibration issue and not link to P gain after my first check)
_Altitude hold : As soon as altitude hold is active, the copter go up or down even if throttle at middle position (with or without sonar)

Log enclosed
SW : ArduCopter v3.4
HW : Pixhawk Mini + GPS M8N + Optical flow + Maxbotix Sonar I2C
Copter : Tarot Robocat250

Thanks in advance for your help

Bourmatt

2

stock gains are wayy too high for a robocat, i have a mini apm in mine and i had to turn pitch/roll rate P and I down to 0.080 to stop the shakes.

have you set your throttle hover position yet ?

3

Hello,

Slightly off topic, but I see that you are using the Pixhawk mini with the maxbotix sonar I2C.

I am too using this configuration (though for a rover build) and cannot get the sonars working. I was wondering if I could ask you how you set yours up?

Thanks in advance,
-Glen

4

Glen,
Did you ever get your sonars working? I am trying to use a pixhawk mini with two Maxbotix Sonars

5

I have not yet. I plan on spending time next week and digging through the code. Hopefully it will be an easy fix.

Which firmware are you using?

6

W1702 Arducopter stab issue.param (11.0 KB)

Dear George,

I tried with lower Pitch/Roll P rate but at this time the issue didn’t disappear. I will try again. Thanks for your feedback

Dear Glen,

I just simply connect I2C from the Maxbotix sonar to my I2C hub and changed some parameter ( parameter list enclosed). Let me know if you have other questions. Thanks.

Bourmatt