Today was the first flight test of my upgraded Easy Star with the ArduPilot installed. I encountered a few problems that will take some more tests to diagnose. Would appreciate any comments.Here is the setup:-Easy Star with the aileron conversion as documented in this RCgroups posting.-FMA Co-Pilot-Towerhobbies 72Mhz 8 channel RX and Tower Hobbies 6XM TX.-EM-406A GPS-ArduPilot with the latest code (22 Feb I think) set to RTL.Previously I tested the Easy Star with ailerons and the FMA Co-pilot and found the performance to be rock solid. The only addition to today's flight was the ArduPilot and GPS. Take off was uneventful and I waited until reaching about 200 feet with the plane flying directly away from me to switch on the Ardupilot. I encountered two problems that I believe are likely unrelated.Problem 1: Shortly after switching on the ArduPilot, the plane started flying erratically, the throttle and all control surfaces moving in an uncoordinated and erratic fashion. I switched the ArduPilot off and was able to recover the plane. A little more testing showed that he plane behaved similarly, even with the ArduPilot MUX switched off. The plane essentially behaved as if someone was on the same channel and/or general radio interference. There was only one other flier at the field (that I could see, its a big park) and they were on 2.4ghz.Possible Solution: Move the Ardupilot and GPS as far from the RX and ESC as possible. If that doesn't work, try another RX, possibly a Berg.Problem 2: During the brief intervals where I was not experiencing this interference, I switched on the ArduPilot. The throttle behaved as expected and maintained altitude. It seemed like the plane was turning towards the launch point, but so slowly that I had to switch off the ardupilot and bring it back manually or it would have flow out of visual range. Again I didn't get to test this much as the interference problem was popping up frequently.Possible Solution: Even though I have enlarged the rudder on the Easy Star, when the FMA Co-Pilot is on and I try to turn the plane with rudder only, it takes almost full rudder deflection to make a reasonable turn. I believe there is a setting in the ArduPilot code to turn up the gain on the rudder which may solve this problem.Would appreciate any comments if it looks like I missed something.
HugePanic...let me know how your modification goes.
John...I do have a video, I'll clean it up a bit and add some comments on when Arudpilot was on/off (as best I can remember) and post. It was a wild ride at times!
Glad to hear testing has begun. Perhaps the both of you can expand on you're experiences with wacky flight characteristics (that hint to be most likely unrelated to ardupilot) as I'm sure several folks will be running into similar issues with similar setups (me for one). Are there any flight videos witnessing these trials by chance?
my plane shows the same behavior. I think the problem is the yawing moment of the ailerons. The rudder turns the plane, and results in a bank angle. The co-pilot tries to steer the airplane back to level flight. Due to the change of lift on both sides of the wing, the cd changes, and results in a counter-yawing moment.....
i am still doing flight test to improve the turn behavior of the plane. I am changing the aileron linkage geomety to reduce this moment....
Maybe this helps your plane too....
Thanks for the comments Chris. Good point on the range test. I didn't do one after adding ArduPilot. I'll do that after I move things around and confirm it passes the range test.
As far as the code..I thought I had the latest version but the dates on a couple of the .pde files look newer on your link so I'll flash the latest code.
I think I will increase the min/max yaw on the rudder servo a bit. Right now it is set to the default setting, what would you recommend as a good first try, 900 and 2200?
Thanks again to you, Jordi and all the other contributors!
That interference thing is bizarre. Did you do a range test on the ground (antenna down)? I don't think that had anything to do with ArduPilot, especially since the MUX was off, but checking connections and moving stuff apart is always a good idea.
As for the second one, the plane should have turned pretty quickly. That's either due to the small stock rudder (we always enlarge ours by 100%), too low gains, or--possibly--one of those code gremlins that we've been stamping out. I'm assuming you've got the latest version of the code (updated this past weekend), which should have solved the GPS lock problem. If not, please download and flash that version.
Comments
John...I do have a video, I'll clean it up a bit and add some comments on when Arudpilot was on/off (as best I can remember) and post. It was a wild ride at times!
Glad to hear testing has begun. Perhaps the both of you can expand on you're experiences with wacky flight characteristics (that hint to be most likely unrelated to ardupilot) as I'm sure several folks will be running into similar issues with similar setups (me for one). Are there any flight videos witnessing these trials by chance?
my plane shows the same behavior. I think the problem is the yawing moment of the ailerons. The rudder turns the plane, and results in a bank angle. The co-pilot tries to steer the airplane back to level flight. Due to the change of lift on both sides of the wing, the cd changes, and results in a counter-yawing moment.....
i am still doing flight test to improve the turn behavior of the plane. I am changing the aileron linkage geomety to reduce this moment....
Maybe this helps your plane too....
As far as the code..I thought I had the latest version but the dates on a couple of the .pde files look newer on your link so I'll flash the latest code.
I think I will increase the min/max yaw on the rudder servo a bit. Right now it is set to the default setting, what would you recommend as a good first try, 900 and 2200?
Thanks again to you, Jordi and all the other contributors!
As for the second one, the plane should have turned pretty quickly. That's either due to the small stock rudder (we always enlarge ours by 100%), too low gains, or--possibly--one of those code gremlins that we've been stamping out. I'm assuming you've got the latest version of the code (updated this past weekend), which should have solved the GPS lock problem. If not, please download and flash that version.
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