MPU-6050 angle readings under mechanical vibrations

[Martynas Jankūnas]

Hello,
I'm in process of making a quadcopter. At this point I encountered a problem with MPU-6050 angle calculation.
When quadcopter is stationary with motors in off state and I'm tilting it, angle readings in all 3 axis is good, but when motors are in on state, readings starts to jump all over the place and can even differ from real value by 20 degrees.
I assume this effect is due to mechanical vibrations caused by motors. I include pictures of quadcopter and MPU-6050 board mounting also a graphs of angle readings of MPU-6050 in X axis using Kalman filter, complementary filter and MPU-6050 DMP (Kalman and complementary filter implementations as well as processing code for graphs is from Kristian Lauszus GitHub https://github.com/Lauszus , DMP used with Jeff Rowberg library from https://github.com/jrowberg).
Maybe someone had similar issues and could help me.

 

[BradtheRad]

I assume this effect is due to mechanical vibrations caused by motors.

Did you try clamping the aircraft to a solid object, then take readings? That would quiet the mechanical vibrations.

 

[Martynas Jankūnas]

Yes, but I didn't put much force or weight to hold quadcopter, because all its base is just a PCB and it's quite elastic, I don't want to damage the board.

 

[BradtheRad]

Filtering could help. Possibly by adding capacitors. Either on the power supply, or on the incoming signal wire.

Also, for testing purposes, try powering your motors from a different supply.

 

[Martynas Jankūnas]

I connected second MPU to different microcontroller, so it would not be connected electrically with a quadcopter and mounted MPU on board with two sponges from both sides of MPU. Results were pretty much the same. Then I put MPU between two copper clads and connected them to quadcopter ground, results was much better, max angle difference from real value was 7 degrees, not 20 like before. I will try to fully isolate MPU with tin foil next.