Hi everyone!
I´m new here...(I know, you´ve read that before many times). I´m in the process of building different multicopter frames (quadcopters, hexacopters...etc.), and testing them with the Ardupilot Full Megakit.
Right now, I´m having some (to say the least) problems with my quadcopter with the Ardupilot Megakit. I´ve programmed the PID settings for Stable and Acro, but with no luck. Every time I try to take off, the Quad tilts to one side and crashes. It doesn´t seem like the Quad intends to fly at all. I´ve tried different settings for P value (I apologize if my terminology is incorrect...think that I´m writing this from Spain!). I´ve set the P value quite low to begin with, because my concern is with stability in the air. That is, no sudden movements, or moving back and forth too much. Ultimately, I would like the multicopter to carry a Canon 5D Mark II camera (1.7 kg). I know that this is impossible with the quad, but I going through testing with the quad (testing settings for PID values) before moving to the hexacopter or octocopter that will be able to actually carry the camera. I´ve kept the I value at 0, as the guide said that it´s better to keep it at 0 than to have and I value that is poorly chosen. The D value I´ve kept at 0.
Anyway, with the P value quite low (I´ve tried between .8 and 1.2), the quad still rushes to one side, and crashes before it can take off.
Maybe this is a problem with the initial levelling?
Or is this a problem with the PID settings? I´ve done the tests in a controlled environment (indoors, no wind), so I assume this is a problem with the settings.
This may sound very very novice...but it´s normal, since I am one. Anyway, I would really appreciate any help at all!
Thank you guys
Replies
Listen to Helldesk and Jasonshort.
And double/triple/quadruple-check your prop direction and motor direction and ESC to APM cabling. If your quad wants to flip over at or before liftoff, it is frequently a swapped set of motors at the ESC, upside-down props, backwards props, or motors spinning in the wrong direction. I've seen other newbies like me spend days insisting these things were correct, and then solve their problem in just a few seconds when they realized there was just one mixup somewhere.
Jason's posts had me add hand-testing to my routine. If you hold the quad firmly, out of range of the props, and spin it up, you can feel which way it pulls. It will lead you to the answer. Also, if it wants to flip or run off in one direction while on the ground, another post he or Helldesk or another fine member here suggested: rotate the quad 90 or 180 degrees, re-power it, and see if the direction changes with the quad, or stays with the environment.
Good luck! And give us some video! Success is great, issues can be seen easier, and disaster .... well, you'll enjoy it later, even if you don't at first. ;)
Alexandra,
There are a series of trouble shooting steps in the wiki that should help.
http://code.google.com/p/arducopter/wiki/AC2_Troubleshooting
Myself, I don't use the Mission planner very often because I'm a Mac user. I use the CLI instead.
Run these commands in this order and follow on-screen instructions and your golden.
setup] erase
setup] reset
setup] radio
setup] level
setup] frame x
setup] compass on
setup] declination 14.25
setup] sonar on
setup] modes
test] radio
Pitch back and roll left should be around 4500
Make sure your motors are spinning in the right direction and the props are on correctly.
Jason
I am almost done testing an Octocopter frame that I intend to sell. It really has some nice features. If you want me to send you information when it hits the market, let me know. It is designed specifically for aerial photography. Good luck with the quad!
Also, you should use the mission planner to confirm that your radio's stick inputs are correctly interpreted by the board. Sometimes you might have a channel reversed, which will cause it to look like it is rolling to the side hard because you might be trying to compensate for that roll when you are actually adding to it.
You might want to try leveling your quad first. I have run into this issue if my accelerometer is not calibrated properly. If you are using the mission planner, you can level the quad by placing it on a level surface, then go to the configuration menu under the setup tab and click the Level button. OR if you dont have it connected to the mission planner, you can level the quad by holding your yaw stick to the left for 10 seconds.
The other time that I ran into the same problem as you, I noticed that my GPS was positioned too close to the top of the APM board, and it was causing quite a bit of interference with the accelerometer.
I really don't think that it is your PID values. You may want to reset those to the stock values and try the above steps.