andigtech / brushless-gimbal

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No PID tuning guide - Wiki needed #12

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
Here's an Idea

Up to now there is not much of a wiki on here, after building a gimball myself 
and (still) having trouble tuning it I think It would be good to update/create 
a wiki and PID tuning guide.

Should include:

- information on making the conections corectly For the hardware.
- How to upload the firmware via Arduino
- How to Open and use the GUI
- Basic Settings and a PID tuning guide.

Anything else?

I know this may seem like basic stuff but it is all helpfull to the people who 
are unsure. I know that having a source of info would of made it a lot easyer 
for me!

I am willing to Write the content and add photos ect.... What I need is more 
info On pid tuning and basic settings. And the ok from the developers to write 
a wiki. :)

Cooke86@googlemail.com

Original issue reported on code.google.com by cook...@googlemail.com on 10 Jun 2013 at 8:36

GoogleCodeExporter commented 9 years ago
Hi,

I have the FG-PH2 Gimbal.

With that said I have found 049-r69 to be the best workable version yet. Here 
are a couple guidelines that you may find helpful in tuning your gimbal. Also, 
I attached my settings for my Gimbal. This may or may not help because I 
believe different motors and gimbals are all a little different therefore 
needing different tuning values.

Only do this if you have BETA Version 049 r69 incl updated GUI. The other GUI's 
and Firmware act differently from each other. Tuning wont work the same way 
because the values and percentages have changed in between the firmwares and 
GUI's:

Power on your Gimbal and then connect the USB to it. Then start the GUI.

1. Zero out your max PWM(%) and PID in both Pitch and Roll.

2. Start by giving the max PWM (%) a value on your Roll. I started with 70 and 
found it to be to much because when I started tuning PID it wouldn't stop 
vibrating. Also feel the motors for heat. If they are getting hot or even warm 
its likely your PWM is too high.

3. Once PWM has a value begin tuning the PID. Start with "P". I started with 
5.0 on "P"

4. Now go to "D" and use the slider bar to give its number value. Slide it 
slowly until your gimbal starts vibrating. Slowly slide the bar in the opposite 
direction until you don't have any vibrations.

5. Press Gyro-Cal button. I find doing this every so often helps give you a 
more precise tune. Also you may find your gimbal going crazy sometimes and I 
find the Gyro Calibration can help mellow it out.

6. Go back to "P" and do the same thing you just did to "D" but start from the 
value you gave it at the beginning. In which case I gave it 5.0

7. Go back and forth tuning from "P" and "D". Make sure to also test the tune 
by moving your gimbal on its roll axis. Once you give "P","D" the highest 
values with out the motors vibrating then go to "I". 

8. I find that if you add "P" and "D" values together it will equal to around 
what your "I" value should be. For example My "D" value was 21.0 and my "P" 
value was 19.6. That equals around 40.0 so I put it at that. I found no 
vibrations so I left it at that. (I used 40.0 for my "I" pitch value as well)

9. Your Roll Tuning should be complete! Save these settings to your gimbal. 
THIS IS VERY IMPORTANT. Follow these 2 steps. #1 Click on the options tab and 
then click "Save to Board". #2 Click on options tab and then click "Save to 
Flash".  

10. Go to Pitch settings. Start the same way as with Roll. Give the max PWM(%)a 
Value. I found that your Pitch PWM value will most likely be less then your 
Roll PWM value. (I believe its because your Pitch and Roll have a different 
type of balance, weight, and stress ratio)
11. Once you give your PWM a value go to tuning your Pitch PID's. Do the same 
steps as you did for your Roll tuning.(steps 3-9)

That should be it for your basic tuning! Remember to constantly press the 
Gyro-Cal button throughout your tuning.

I hope this helps! If anyone wants to chime in on my instructions feel free. 
Again this process helped me tune my gimbal. I believe its possible that it can 
be done for different gimbas as well.

Good luck

Original comment by alphap...@gmail.com on 11 Jun 2013 at 3:56

Attachments:

GoogleCodeExporter commented 9 years ago
Hey this info is great, It is exactly what I was looking for. Do you know what 
each of the values corresponds to (P,I,D and PWM)? It would be goo to know what 
factor you are changing while tuning.

I will give it a go in the next few days and post results here.

How would I go about getting the rights to be able to create wiki pages? who do 
I need to email/speak to? I think a small wiki with the layout of the 
arducopter wiki would be great for the project.

Original comment by cook...@googlemail.com on 11 Jun 2013 at 8:58

GoogleCodeExporter commented 9 years ago
By the way my gimball is homebuilt design, For a DSLR. My camera is a canon 
650D.

Martinez controller and iflight 5206-150T motors

Its quite big.

Original comment by cook...@googlemail.com on 11 Jun 2013 at 9:05

Attachments:

GoogleCodeExporter commented 9 years ago
I'm not sure what each of the values corresponds to.

I have no idea who to contact for getting rights. Perhaps open up a new issue 
about getting rights to make a Wiki and hopefully they will see it.

Your rig looks great. Defiantly way different setup then mine. Mine only 
carries a GP3. I would assume your PWM and PID values should be higher then 
mine if that helps.

Original comment by alphap...@gmail.com on 13 Jun 2013 at 1:00

GoogleCodeExporter commented 9 years ago
I contacted One of the owners and got access to the wiki, already made some 
pages.

What else should be in it? :)

Original comment by cook...@googlemail.com on 14 Jun 2013 at 8:09

GoogleCodeExporter commented 9 years ago
The essentials about PID loop control were published in some books by the world 
renowned Greg Shinsky....who I was fortunate enough to meet and introduce at an 
O&G symposium in Calgary, Alberta many years ago. Just search for his name. P = 
proportional and is simply an attempt to ramp towards the target setpoint which 
it can never quite achieve with I&D functions....I = Integral which is 
sometimes referred to as "reset" in the automation industries. It provides some 
overshoot to get to the target setpoint faster but tends to overshoot..... 
consequently D = Derivative has to be added at that point...D is often referred 
to as Rate in the automation industries. So Greg Shinsky and others will 
suggest you start with P tuning, then add some I tuning, working back and forth 
until you get very good results..... and finally add some derivative but only 
if you must..... Derivative tends to create a lot of instability if there is a 
lot of rapid changes going on with your control system...... Now if the PID 
tuning is done according to convention above will work...... if someone who 
developed the code did it outside above definitions etc. all bets are off.

Original comment by gtranqui...@gmail.com on 27 Jun 2013 at 11:00