I have just bought the ArduPilot Mega 2560 Full Kit... plus the Triple Axis Magnetometer HMC5883L. I should have it built over the weekend.. then i'm off to a my mates machine shop, and i'll make the splitter plate for the lower frame onto which i am going to fit the Ardupilot. the magnetometer i'll put on the tail as suggested. I am going to use my X-cell Razor 600E. For those that dont know its around the 50 size nitro heli.
Do i need to buy any other sensors i.e. the Sonar... i can fly a helicopter all day long but this is my first time flying one with stabilisation so any tips would be gratefully appreciated.
If this works well then i am going to try and use it on my x-cell gasser. i can get up to 20 minute flights with this. But i think for the time being a battery 600 is the way to go.
i'll post some pictures when i have it all together.
That's what I'm thinking. A little I term might be ok, but if it's too high, for sure it'll wander all over the place.
Ok christoph thanks for that i'll try again over the weekend ....
Malcolm. Which software version were you flying last weekend?
i'm using 2.4.1 compiled with arduino ..
Ok, and even with that you had similar loiter issues as I had with 2.1.0.
I just need to make up my mind, if I should upgrade now to 2.3 at least, to continue testing loiter but now with D terms included.
I am a little sensitive to software changes, as past experience showed me, that often I was thrown back three steps because of some software changes. You might remember the whole stick scaling issue, which I solved so far by using an old heli.pde, from a version before that stuff was introduced.
I am trying to setup a 450 clone but the tail seems not working at all. If I use no gyro, the tail servo moves a limited range that won't hold the tail in flight at all. If I use gyro, the tail will wag even I set the gain on gyro to 0, so it seems the APM is trying to act as gyro in this case.
Can any one share a set of parameters as a reference?
When you change between Gyro/No Gyro, are you toggling the control in Mission Planner for the external gyro?
When you have no Gyro, you need to make sure to turn that checkbox off. Then, your PID settings for Stabilize Yaw and Rate Yaw are very important. In particular, the P terms. I have my Stabilize Yaw P at 2.000, and Rate Yaw P at 0.350. Give those numbers a try.
Robert, thanks for helping. I set the parameters as following and gyro box is checked off.
The tail does respond to rudder stick and heli movement, but the servo moves very limited range (about 1/4 of normal range?). The servo moves full range if I use a external gyro to direct control it.
Let me know if I should also check other places. Should I use any of the unofficial firmware builds? I rely on APM to upload the correct firmware.
Stick with the Mission Planner firmware for now. We should have a new one coming out in a few days.
Try increasing Yaw P. Just set it to 1, see if the movement increases. But I wouldn't try flying like that. Just as a test. I suspect it will oscillate. This is the old "gain" you used to use on an external gyro.
Set it back to 0.35 for now. Then, try increasing STB YAW to 3, 4, 5... see what you see?
I honestly haven't played with it that much, because it just *works* for me. I don't think you will never need the full travel of the tail, because we aren't doing 3D.
Also, you need to check what the servo limits are on the tail in the AC2_Heli tab. Maybe you set them low?
When you used the external gyro and it wagged, which gain is it you set to zero?
I just completed 2 good flights with the code from trunk (from
yesterday) in my heli.
Overall, it went quite well. The compass was perfect. I flew at the
suspected Bermuda triangle field, and everything was fine. I have no
idea what the issue was last time.
Again, this is with my backwards APM and compass, on a highly
yaw-active heli, no problem with heading that I could tell... so the
code seems pretty robust. Well, I had a huge slew to the left
everytime I stabbed the throttle, but I assume this is just due to
rotor torque which we can work around. I would like to have a
look and see what my magnetic field looks like to confirm it's not
I played with h_collyaw a bit for the first time, and got it up to 5
without really feeling like it was helping. Then I looked at it on
the ground and... I think it's working backwards! Randy, I'll
I tried some Alt_hold, and quickly realized that my sonar is just
rubbish. With any throttle_P at all, it just goes crazy. I don't
know what the problem is. Well, I have an idea. It might be my tail
support booms slapping against the plate which holds the APM and
sonar. But both are isolated from that plate by nice rubber mounts.
So I wouldn't expect that. Regardless, I'll remedy that situation and
test again. If that's not it, then I have no idea. The sonar is
heated, filtered, and the wires aren't shielded but they are only
about 1" long. The sonar is rigidly bolted to a rigid bracket which
is rigidly bolted to the APM case giving a nice lump of mass, and the
lot has some really nice rubber damping, and the heli right now is
about as vibe free as it's going to get. It should have a smooth ride
and not be subject to mechanical vibration.
After I turned off the sonar, I tried some more Alt_Hold and it was
generally fine, though it wandered a lot, that I can work on.
I tried some loiter, which was not great but didn't do anything really
spooky. I tried to let it wander to see what it would do, but it
seemed like kept wanting to wander over my head so I aborted cause
that's not cool. I need to tune that as well, but first have to
figure out how.
Now, I did have something very strange that happened in the included graph.
You can see some massive spiking on Thr_In and RC3_out.
That was NOT me, and I don't think it was (shouldn't have been) in
Alt_Hold. Where did these come from? I noticed it at the field, I
thought maybe my ESC or motor was giving out. It was a really sharp
vertical shaking. I landed, checked things out, everything seems
fine, so I took off again, and it was fine.
I assumed it was a mechanical problem until I got back home and looked
at the logs. Why is Thr_in moving like that? It must be a bug, or a
radio glitch is all I can figure? But I'm running 2.4Ghz, and it
didn't affect any channels other than throttle. I have no idea, so I
think we should look at it.
I was finally brave enough to update tp the latest MP and also loaded now 2.4 coming from MP.
Thanks to Randy and you! You sorted out my stick scaling problem. I could finally setup the heli and the servo mid positions without these crappy reactions I had before. Thanks!
Is there anything I need to worry about version 2.4 coming with MP? On the bench reactions look ok.
Any need to worry about your THR_IN peaks?