Dear Diydrone members, I am stuck and I really hope that one of you might be able to help me. As indicated in my previous post I am able to successfully build and fly a 450 size electric heli. I have a 50 size nitro heli and I wanted to make it autonomous using PIXHAWK. Just to check the vibration level, I installed the controller while the helicopter was still RC. Unfortunately the vibration was too much (Way beyond .2g).
Just like for the 450 size heli, I installed 2 carbon plates 2.5mmthick as box. I did three experiments with this setup without much success.
CASE 1:
I installed the controller in a plastic lunch box. Unfortunately the vibration was too much. A lot of "Err: EKF_CHECK-2" and "Err: EKF_CHECK-0" showed up in the log. Vibration was +-0.4g in X and Y direction and +-0.6g in Z direction. Most of the time EKF2.Ratio has the value 100.
CASE 2:
Since the controller was in the box and box was attached to the carbon plates, I decided to attach the controller directly to the plates. I assumed that the extra vibration was because the controller was not directly installed on the plate. So using a foam I installed the controller directly on the plate. However the results were almost the same and I still got the EKF errors. Most of the time EKF2.Ratio has the value 100 or 0 very rarely it has intermediate values.
CASE 3:
I read a lot of good stuff about this 3d Printed vibration damping system
So I installed it on a plate at the front of the heli. To my utter disappointed the performance was way worse. On Y axis the vibration was 3.0g (3 times the earth gravity). This was really disappointing to me. However I must say that the location of the controller was changed. Rather than being installed on the lower plate of the box I created, it was installed in the front part of the heli. Perhaps that part naturally has more vibrations. What was surprising is that in this case even though the IMU vibrations were so bad, I did not see any "Err: EKF_CHECK-2" errors in the log. I have no idea why this happened. I would like to understand it's reason. Most of the time EKF2.Ratio has the value 50. For very small part of the log it is 0 or 100.
I was hoping to get some guidance from other builders who have successfully installed PIXHAWK on a nitro heli. I am completely stuck at this point.
Replies
This is a gasser, right? Nitro? Any gas/combustion engine vehicle will likely be inherently vibration prone. I haven't heard of many people using gas powered helicopters/multicopters without having to get really serious about vibration damping. I have that same mount, but I'm using brushless motors/electric.
Hope you can figure something out. Maybe someone has a suggestion?