Version 2.5 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area!

 

Enhancements:

  1. The first ArduCopter code release optimized for the APM 2.  Leans and drift should be much reduced or even eliminated for most users.  This was accomplished through a number of core improvements to the DCM implementation by Tridge like this one and this one.
  2. Loiter and waypoint following should be improved due to a D term bug fix, some tuning and the improved DCM performance mentioned above.
  3. On start-up, the yaw heading is updated with first successful mag read (so you should no longer see the slow rotation from north to your actual heading).
  4. Increased output rate to ESCs to 490hz.  This update rate is also user selectable using the new RC_SPEED parameter.
  5. hexa copter stability patch bug fix (should resolve slight flattening when pitching forward and accelerating very rapidly).
  6. improved baro filtering
  7. fix to dataflash logging of Mag heading
  8. addition of H1 swash plate type and bug fix for proactive yaw compensation for collective pitch changes for TradHelis.

 

Tuning:

The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P in 25% steps.

While some testers have reported very good flights with the default PIDs, some have reported that this release is a little "sharper" due to the DCM improvements and have found they needed to:

     reduce stabilize P by 10% (i.e. 4.5 -> 4.2)

     reduce stabilize D by 30% (i.e. 0.15 -> 0.10)

     increase rate D from 0 to 0.001

Tuning loiter can be tricky.  Refer to the discussions which will appear below for more community feedback on what parameters work best.

 

Please post your feedback in this discussion.  For enhancement requests  and bug report, please add them to the arducopter issues list.  When possible please include logs (tlog and/or dataflash) and tell us whether you're using APM1 or APM2 and what version of the software you're using (presumably 2.5 but tell us anyway!).

 

Thanks for this release go to the developers (both in the core team but also those who have provided bug fixes through the issues list) and also the community members who participated in the previous release thread and provided some great detailed information in the form of issue reports and logs which allowed us to nail some bugs!

 

Tags: ACM, APM1, APM2, Heli, Quad

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I agree 100%.

I'm trying to adjust loiter and yaw PID's and it's very hard to get good results in windy conditions.

I like that idea, it would make finding what your looking for a lot easier.

Hey,

I implemented a couple of months ago the stability patch for Y6 that is missing since long but I still don't see it implemented in 2.6 epsilon. Anyone can test it and include it to the public release, please? My Y6 will be ready soon and I would love to have the stability patch on it.

here's it:

http://code.google.com/p/arducopter/issues/detail?id=375&q=y6

Augusto,

      I haven't forgotten about this fix.  I've had a lot of time constraints in the past month but it's going to clear up in a couple of weeks.  This won't make it into 2.6 unfortunately but I'm confident it'll be in 2.7 (or maybe a patch release of 2.6 if we need to do one).

ArduCopter 2.6 Epsilon is now available in the downloads area for beta testers.  Hoping that this is the final version that will be pushed out to the Mission planner.

 

A couple of things to be on the look-out for:

    a) Please try Simple Mode. The copter should not spin.

    b) Empty dataflash for some APM1 users.  We have one report of this (from Dean) so I'm interested to see if anyone else has seen this.  It's possible that it could be a dataflash hardware problem exposed because of the new method we're using to erase the dataflash.

 

     thanks for your help!

 

Changes from 2.6-Delta:
   - throttle range improvement (higher min and max) [Jason]
   - improved standard Loiter PIDs [Alan, Heino, Jason, Angel]
   - restored standard yaw control [Robert/Randy]

Improvements over 2.5.5 include:
   - Stability improvements especially during level hover [Jason]
   - MavLink 1.0 support (use with ArdupilotMegaPlanner10.exe) [Tridge, Craig]
   - dataflash erase speed up ('+' messages removed but it only takes 6 seconds now) [Tridge]
   - Copter LEDs [Robert Lefebvre]
   - RTL loiter stage target set to home to improve final landing position [Jason]
   - flip & acro improvements [Jason]
   - circle mode target improvement for ground station [Jason]

Bug fixes include:
   - UBLOX driver fixes (lock should now be more reliable) [Tridge]
   - enable mavlink messages during dataflash erase which resolves issue in which new APMs fresh from the factory appeared unresponsive [Tridge]
   - proper printing of lat/lon values in dataflash logs [Randy]
   - removed duplicate GPS reads [Jason]
   - resolve flooding of telemetry link with low-battery warnings [Tridge]
   - RTL bug would land if rtl_approach_alt was more than 1 [Jason]
   - WP Radius could not be set larger than 1.3m [Jason/Randy]

-Randy

Cheers, will give it a go. I did have the problem with logs not being created on APM1 after I moved from 2.5.4 to 2.6 delta. I hadn't cleared my 2.5.4 logs when the logging wasn't working, and as soon as I did, the 2.6 delta logs started to work.

Right, so my logs worked when going straight from 2.5.4 to 2.6 epsilon without clearing them.

One thing I have noticed, is that I will get a constant lean to the left hand side, even after I auto-trim for it to pretty much be hovering in place. I will go into auto trim using the ch7 switch, then get it levelled, and pretty much as soon as I go out of auto trim, the copter will lean to the left and drift left. If I re-engage auto trim, it will stop the lean to the left, and resume the lean if I leave auto trim again. I am flying in an underground carpark which has no wind.

I am running a tricopter with all regular rotation props, which naturally causes a slight lean to the left, but I don't think its right that it should lean to the left after trimming to be level.

Also I was previously having trouble with the tail twitching upwards, and the yaw oscillating with 2.6 delta, and both of these issues have gone now.

Glenn, do you have any Stab_Roll_I, or pitch?  On my helicopter, I found that having a non-zero stab-I led to a somewhat random leaning.  I now set it at zero and recommend other heli fliers do the same.

I discovered this similarly to how you have:  I found that it hovered better in auto-trim than it does in standard Stab mode.  And you know what the difference is?  In auto-trim, the I-term is held at zero.  With that aha! moment, I set Stab-I to zero, and it hovers better.

Yes I had 0.1 for Stab roll and pitch I. I'll try setting it to 0 and see if it fixes it.

So I have set stab rate/roll I to 0, and it's noticeably better.

One thing I keep coming across is that perhaps the auto trim values aren't fine enough. Eg I will enter auto trim mode while hovering, and will make the smallest taps on the sticks that I can to oppose any drift, and then not touch the sticks and see if it's still drifting, but it's very hard not to cause an overshoot in any direction. If the trim that is being added as part of this process was smaller for each tap on the sticks, I think it would make it easier to get to a perfect drift-free hover without overshoot.

One way to improve this is to put about 30% expo in your tx for roll and pitch, this will given you tighter resolution around the centre point whilst auto-levelling.

My log for this flight is here. Is there a way to show in the log when auto trim is enabled vs not?

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