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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ok, but can you explain why? is the 1100kv less powerful?

For those of you with yaw related issues please see my new blog post. It may help you.

http://diydrones.com/profiles/blogs/resolved-arducopter-2-5-3-yaw-i...

If the link is broken just give it a few minutes. I think the blog post is still waiting for approval in the moderator's queue.

Adam

Have you had a chance to look at the log files i sent you?

I'm have many more issues with the APM 2 board that  I think has been caused by me and my computer.

When I plugin the battery most of the time I get only a blue LED instead of the blue and red flashing LEDs.

Often one of my ESC throttle calibration is change and it continues to beep till I recalibrate it.

When the APM 2 is connected to the MP the update rate for the artificial horizon and is slow.

I've used a different computer and did a complete install of mission planner and 2.53 on the APM 2 and nothing has changed.

Is there a way to remove all the configuration files from the APM 2?

Is there a place I can send my board to get it fixed?

Larry

Hi Larry,

To remove all the configuration files from the APM 2, connect APM2 to pc using USB, open mission planner, DO NOT CLICK CONNECT!


Click terminal window in MP.


Once its opened the port and connected, type 'setup' and hit enter then type 'reset' and hit enter

Then for good measure, when its finished that, type 'erase' and hit enter

This will clear all data from the eeprom and it should be 'factory fresh'

Good luck :)

Dave

I've done that all except the erase part.  I'll see if that works.

Larry

Aerhead,

I often experience the issue with just the blue LED coming on. Mostly resolves after I disconnect battery and start over again. Seems to have correlation to X-Bee link not properly disconnected after previous session, but that´s just my therory. Sometimes no LED at all comes on...  There is something random about the booting sequence...

About slow horizon - sounds familiar. Maybe similar to this and this. Check if power-up sequence (according to the links provided has impact.

Good luck / Tomas

I have had just blue locked on at random, but no need to unplug - just hit the reset switch on APM2 and it boots every time. Maybe just a short delay at beginning is needed.

How well should we expect a stock 3dr quad kit to cope with gusty wind? I was having serious trouble trying to manually control mine to stay in one spot this afternoon with maybe a 35km gusting wind. Whenever a gust would hit, it would oscillate, sometimes quite wildly (maybe 40 degrees or so), and sometimes it would take off in one direction or another as a result. 

I'm running 850kv motors with 10x4.5 props on the latest git 1.5.3 (also tried straight mission planner 1.5.3). I'm just on default PIDs at the moment, tried turning rate_p up to .15 thinking that if it could counter the gust faster that might be good for stability but that just started to jitter so I turned it back to 0.14.

Where I live it is windy more often than not, so does anyone have any good strategies for PID tuning or getting by in a windy area?

I am also noticing that the yaw doesn't hold exactly, on previous code sometimes it would yaw significantly clockwise when I gave a boost of throttle, and usually back again when I backed off, even on a calm day. Haven't had a chance to test other than in the gusty conditions today

This is what I found to be a good solution for windy conditions:

Set STAB_I to 0

STAB_D to a very little 0.001 (you can play with this later) or even 0.

RATE_P 0.14

RATE_I 0.02 or 0.015

RATE_D 0.003

It was on a custom frame, but what I have found to be the anti-wind parameter is the RATE_D.

The P is Proportional to the error so if there is no error it will not be useful and it will take time to react.

The I is used to account for bias (like a constant wind) and is relative to error change in time.

The D in PID is the parameter that counteracts faster to a suden change, infact it accounts for the change in error form the previous readings.

I have flown in very strong wind with almost hands free! Believe me or not....

But be careful with the D, because if set to high it could have a really bad behaviour.

What I suggest is to test in relative calm conditions and fine tune the P and D, then go with I if necessary. Otherwise leave it to 0.015.

D should be incremented in 0.001 steps as it is very sensible.

Please let us know if this actually worked for you.

Cheers,

Emile

Thanks, that seems to have improved the performance in gusty wind. There's not so much oscillation now.

Without wind it seems the quad is quite stable.

In constant strong wind, you mean you were hands free in loiter, or you were hands free except to pitch yourself into the wind to stay in one spot? Whenever there's any sort of constant wind, the quad will drift with it at the speed of the wind unless I fight it, but this is normal right?

Well the quad was almost still with wind gusts. I was pretty amazed, but I was not in loiter at all.

Of course if there is some costant wind, it will (sooner or later) fly away, but that is normal.

The fact, I think, is that the D term really kicks in fast, so as soon as there is a gust, the copter counteracts enough to stay almost still. The D term really works well with unpredictable external interference.

But as a side effect, if your copter has many vibrations, the D term will be very bad because internal noise will let the controller think it is external noise, and scillations will occur.

So the best think is to isolate as much as you can the electronics and get a nice calm environment to get all parameters right. Then fine tune in real life...
Glad this helped.

Emile 

Flying with Hexa, APM 2 hardware:

Does anybody else has the same problem as I do?!

in Acro and Stabilize modes flying perfect (2.5.3 better than ever before!)

but then I hit Auto mode (waypoints) engines almost quit and hexa started to fall from the sky. Lucky had enough time to recover. Where should I look for problem? Checked the altitude (was lower than preset for waypoint) and tried few times. Not sure where to dig for the problem? Thanks


Virgis

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