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.

 

 

Setup Instructions

Tags: helicopter, instructions

Views: 42169

Reply to This

Replies to This Discussion

I guess that solves the problem. will try to test that PIDs tom. :) I used the code from the GIT.

hi randy. we tested again this am. any ideas what to do with the loiter? also the guided mode speed is fast.  we lowered the p, we'll test again what would happen.

 

heres the video.

http://youtu.be/CxEBe2Ntkqg

sadly our second test is not that good since our gps is inaccurate. maybe to the number of satellites available. this sucks.

Marianne,

     I've never actually used guided mode so no guarantees on that.  I think it would be best to start on loiter and get that working.  I think in the video you engaged loiter for a moment and it started flying away?

     Make sure you have GPS lock first (the red light on the front of the APM will go solid - i.e .not flashing).  Also make sure the compass is returning good values.  I recommend you use the TUNE value (i think you set it to 12..it's 11 or 12, i forget which) and that will allow you to set the Loiter PID controller's P value while in flight from channel 6.

-Randy

I wonder if that's what I was flying on?  You remember I downloaded Saturday night from Git I think?  I notice there's a 1.0.89*b* APMP that was uploaded 12 hours ago.

 

I think I did see the Acro Roll and Acro Pitch in my APMP setup, was wondering about that. 

 

It sounds like you're saying there is only one setting for each mode now.  Stabilize Roll and Acro Roll.  But I still see Rate Roll there so what does that do?  Is it just vestigial in APMP Setup?

 

Deadband: does that apply to AC's internal stabilizing inputs, or ONLY to incoming stick commands?  I put about -33% Expo in my radio, so in addition to the deadband, I think it's a bit much.  For me, I think that deadband should only filter out any noise in the radio link, but not inputs.  I'd rather soften the controls in my radio with Expo.  How can I tune it back, need to #define it and recompile?

 

What does "Lock Pitch and Roll" do?

 

And Throttle Rate vs. Altitude Hold?

The Rate Roll won't do anything for a heli but for a quad it will be used because for them they still use a nested controller for stabilise mode.

 

The deadband is only used for the radio input.  There's no deadband for the heli's output to the servos.

 

"Lock pitch and roll" likely just copies the PID values between the appropriate roll and pitch sections as you update them.

 

Throttle rate and altitude hold are the two nested controllers for altitude hold.  So the outter controller (altitude hold) will look at the distance from the target and decide on a rate of ascent (or descent).  It will pass this to the inner controller (throttle rate) which is responsible for implementing that rate by moving the swash up/down.

Ok, so to make sure I'm clear:

 

Quads still use nested controllers.  In stabilize mode, the stabilize PID's operate on top of the Rate PID's.  In Acro mode, they only use the Rate PID's.  Quads do not use "Acro PID" at all.

 

Helis no longer have nested controllers.  Stabilize mode ONLY works with the stabilize PID's.  In Acro mode, we only use the Acro PID's.

 

My "death wobble" was most likely due to the the Acro PID's being untuned.  Yeah?

 

So, I just saw the announcement for the new T3 competition, and I'm thinking of giving it a shot.  Is that realistic, or are we way too far off from getting a heli to fly waypoints?  Obviously I need to do a lot of tuning yet, but is the code there?

 

Another question: is there a mode whereby we can fly the heli and have the tail always automatically point back from whatever direction the heli is flying?

 

 

Close...

>>Quads still use nested controllers.  In stabilize mode, the stabilize PID's operate on top of the Rate PID's.  In Acro mode, they only use the Acro PID's. 

 

This part is exactly right,:

>>Helis no longer have nested controllers.  Stabilize mode ONLY works with the stabilize PID's.  In Acro mode, we only use the Acro PID's.

 

Yes, death wobble from trying to use untuned acro pids.

 

Technically the code is there for the T3 competition so it's possible.  If the quad can do it the heli should also be able to do it given it's tuned.  Have you tried the simulator?  I would definitely get it working in the simulator before giving it a try in real life.

 

I think what you're asking for is a modified simple mode.  I raised Issue #248 to cover this.  simple mode is there but not this modified simple mode.

Ok so on the PID's.  If Acro PID's are also used by the quads, then I guess we don't need a new tab just for helis.  I would only request maybe if we could change "Throttle" to "Throttle/Collective", that'll just make it a bit clearer for heli guys.

 

So heli's don't use Rate Pitch and Rate Roll, but we DO use Rate Yaw, correct?  Because that's the one I played with to get my tail servo to move properly in Acro mode. 

 

Are the yaw PID's still nested?  Or is it Stabilize for Stabilize and Rate for Acro?

 

Throttle/Collective PID's: Altitude Hold PID controls the heli's response to altitude error in Alt_Hold right?  It feeds a rate command into the "Throttle Rate" PID, in exactly the same way as the collective stick does when flying in Stabilize?

 

I believe the AltHold PID controls the altitude when flying a mission, correct? But what controls the rate of ascent/descent when you command an altitude change?  Hopefully it's not simply a case where the altitude error goes directly to the proportional controller? So if I command the heli to rise 100m, it'll output a massive collective pitch change causing the heli to skyrocket.

 

I see in the Nav WP PID block, that we have "m/s", which is where we set target airspeed.  Is there something similar for altitude changes?  That's essentially what I'm asking.  I think I saw something in the code, but I'm not sure.

 

Simple mode:  Yeah, that would be good to have a special simple mode.  However, I'm more concerned with flying a mission.  So perfect example is the T3 pattern.  The heli really should face the right way.  It's not a big deal for a quad, but for a heli, if it tries to fly backwards at speed, it's not going to go well.  The tail will try to weathervane, and if the AC is trying to resist that, could get ugly.

So heli's don't use Rate Pitch and Rate Roll, but we DO use Rate Yaw, correct?  Because that's the one I played with to get my tail servo to move properly in Acro mode.

Yes, as long as you have external gyro disabled.

 

Are the yaw PID's still nested?  Or is it Stabilize for Stabilize and Rate for Acro?

Yes, still nested.  So both stabilise and acro flight modes use the Rate Yaw section of the APMP configuration screen (as long as you have external gyro setting disabled)

 

Throttle/Collective PID's: Altitude Hold PID controls the heli's response to altitude error in Alt_Hold right?  It feeds a rate command into the "Throttle Rate" PID, in exactly the same way as the collective stick does when flying in Stabilize?

The throttle scaling doesn't happen.  Also in stabilise mode the pilot's commands go directly to the swash plate, there's no interfering with them in anyway by the APM code.

 

I believe the AltHold PID controls the altitude when flying a mission, correct?

When in a mission, or ALT_HOLD flight mode or even LOITER.

 

But what controls the rate of ascent/descent when you command an altitude change?  Hopefully it's not simply a case where the altitude error goes directly to the proportional controller? So if I command the heli to rise 100m, it'll output a massive collective pitch change causing the heli to skyrocket.

There's a maximum error of 3m fed into the controller..so whether it's 3m or 300m, it won't respond any faster.  Most of the controllers have some maximum hardcoded in.

 

I see in the Nav WP PID block, that we have "m/s", which is where we set target airspeed.  Is there something similar for altitude changes?  That's essentially what I'm asking.  I think I saw something in the code, but I'm not sure.

Not anymore.  there might have been something like that in the past because i see some comments that suggest that but looking at just the code, it looks like the altitude error just goes straight into the alt_hold PI controller and then the results of that go into the rate PI controller.

Simple mode:  Yeah, that would be good to have a special simple mode.  However, I'm more concerned with flying a mission.  So perfect example is the T3 pattern.  The heli really should face the right way.  It's not a big deal for a quad, but for a heli, if it tries to fly backwards at speed, it's not going to go well.  The tail will try to weathervane, and if the AC is trying to resist that, could get ugly.

I'm sure that when doing a mission, it will modify it's heading to point at the next way point. 

 

Hope this helps.

 

I have been flying with HXT900 servos with limited success.  I think they are too jittery and too slow to work well with the flybarless head and the APM.  What do you guys think?  What servo's are you using?  I am thinking about ordering something else.

 

 

My set-up is on the wiki here in the "tested" column.  So for me I use the standard align servos that come with the trex450 super sport which is a "DS410M Digital metal gear" servos for the main swash and a DS420 for the tail.

 

If you find the hxt900s are no good we should update the wiki page with some better alternatives so looking forward to the feedback..

RSS

© 2014   Created by Chris Anderson.

Badges  |  Report an Issue  |  Terms of Service