I recently swapped out a Pixhawk clone hk pilot32 for a micro HK APM on the same frame and propulsion system. Practically I only changed the flight controller. Firstly I do realize that I can never make the APM be the same as the Pixhawk, as the processing power is not comparable. However I do want to make my APM better so I can confidently to fly it over water.
My pilot32 was able to do this on very high winds:
You can view the log file and kmz file of the flight above. They are the 94.* files on the link below. The log files with dates are from the APM.
I want to fix a few issues on the APM:
- the motors seems to throttle up and down, especially during alt hold or holding position on loiter. It does also happen while flying, but a lot less. I have lowered the Throttle Accel, so it would be smoother with making it too sluggish at it has difficulty flying with wind.
- it maybe related to the above, but it vibrates during acceleration. This produces a bit of a jello on the video.
Replies
I understand you are likely over this topic but I thought you would like a possible explanation. It is my experience that faster or slower FCs sample rates are effected by resonant frequencies, depending on the closeness of the frequencies to the sampling frequency. This leads to some odd behavior from the FC.
Assuming you have a vibration dampener beneath your FC, try adhering a small piece of sheet lead under the plate. Adding weight to a multirotor is not usually the norm, but this will usually fix this issue in most cases.
When tuning PIDs always start at zero I and D, adjust the P then go to the I. D is of nominal value and usually causes more issues than it fixes, though small or default D values usually have little effect.
Thanks for the reply. I have swapped out the APM and put it on a larger frame. I have put it back the pixhawk. I was able to make the APM better, but the pixhawk faster response suited the frame better.
Glad you had some success.
Cheers.
I have since gave up tuning the micro APM on this frame. Decided to put the HK Pilot32 back, and put the APM into a HobbyKing Super H600 frame. The APM seems to be more at home on it. Its got the same ESC, but just using 2212 motors and 1038 props.