Alexmos Tuning Help

[alib10]

Sorry i have to make an alexmos thread.

I've tuned multiple gimbles, but i've not run into this problem before. No matter what i do with the PIDS, i get this shape of graph on both pitch and roll error, when moving the gimbal by hand and then releasing.

I have tried different PIDS, and even tried reversing the motors (which strangely made no difference) but i still just get different variations of the same shape.

Any ideas.

View attachment 17524

 

[gtranquilla]

A bit more background information would be helpful such as....
1) Are you simply changing the attitude of the MR gimbal housing to cause this or are you pushing the camera away from the setpoint to see how it returns to the setpoint?
2) How many and which other BGCs have you worked with?
3) What camera and gimbals are you working with?
4) Which Alexmos are you working with? i.e., the original low torque or the newer higher torque version?
5) In the case of Martinez BGC you also have a motor torque or deadband parameter... if set wrong you will get similar issues or a persistent micro-ripple (nothing to do with PID loop tuning)

Sorry i have to make an alexmos thread.

I've tuned multiple gimbles, but i've not run into this problem before. No matter what i do with the PIDS, i get this shape of graph on both pitch and roll error, when moving the gimbal by hand and then releasing.

I have tried different PIDS, and even tried reversing the motors (which strangely made no difference) but i still just get different variations of the same shape.

Any ideas.

View attachment 21616

 

[alib10]

answers in red.

A bit more background information would be helpful such as....
1) Are you simply changing the attitude of the MR gimbal housing to cause this or are you pushing the camera away from the setpoint to see how it returns to the setpoint?
Pushing camera away from set point
2) How many and which other BGCs have you worked with?
Used flyduino with 2.3 loaded. now using yun 3x with 2.3
3) What camera and gimbals are you working with?
AG500 gimbal with nex 5 18-55mm lens. balanced as best as i can
4) Which Alexmos are you working with? i.e., the original low torque or the newer higher torque version?
didnt know there was a low torque and high torque version, unless you mean firmware 2.3 vs 2.4... im using 2.3. with voltage reg set at around 12v.
5) In the case of Martinez BGC you also have a motor torque or deadband parameter... if set wrong you will get similar issues or a persistent micro-ripple (nothing to do with PID loop tuning)

 

[gtranquilla]

I never pushed my little GoPro camera away from setpoint to see how it responds but no issues in flight.
I am not familiar with the other equipment you listed.
But above is good info that should help others to answer better....

 

[econfly]

The image in the OP is not obviously a problem. If the camera is pushed then the positional error should be there. Is it the time to return to correct position on the pitch axis that is the issue or is it the z-axis acceleration? Usually the acceleration (rather than position error) graphs are more informative about whether things are balanced and tuned correctly, though I may be completely missing the point here.