Altitude Hold and stability

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


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 ?


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,

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

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?

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.