Version 2.6 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area!
Updates to MavLink 1.0 means you will need to use "ArdupilotMegaPlanner10.exe" to connect. If you've updated your mission planner recently you should find this executable in the directory where the mission planner is installed.
The above video is done using a prototype 3dr ublox GPS which seems to have better accuracy than the standard mediatek.
Improvements over 2.5.5 include:
- MavLink 1.0 support (use with ArdupilotMegaPlanner10.exe) [Tridge, Craig]
- Stability improvements especially during level hover [Jason]
- throttle range improvement (higher min and max) [Jason]
- improved standard Loiter PIDs [Alan, Heino, Jason, Angel]
- 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]
- Auto Approach [Adam Rivera / Marco]
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]
PIDs are optimised for the 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props and are seeing bad flight behaviour in stabilize, start by turning down Rate Roll P in 25% steps.
This time we spent some time optimising the loiter PIDs. Tuning loiter can be tricky so please refer to the discussions which will appear below for more community feedback on what parameters work best.
All feedback welcome below. Enhancement requests and bug reports can be put into 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 2.6 but tell us anyway!).
I'm using 11x4.7 Carbon GemFans and have found them excellently balanced out of the box.
Their adapter bushings are a little tricky though, requiring careful removal of the connecting sprues and filing, sanding or reaming a slight chamfer to the edge where you insert them into the prop because they tend to grab and gall on the sharp carbon propellers bushing well edge.
I am running a KK X525 quad with an APM2 and I can tell you the GemFans are superior in every way to the stock GWS 9" 3 blade prop that comes with them. Less power consumption, higher performance and much quieter.
Your little camera is a very good lesson in RF interference to the GPS being a really good thing to avoid.
Occasionally I have though my quad might have had similar aspirations.
Today I've sent it back to the store. I didn't get any error, simply it was like the gps/compas was completely dead. I recorded this video.
It's definitely a corner case for the FC. Very turblent, swirling flow with a velocity to it. Not easy to stabilize. From what I have read about other controllers, they generally handle it pretty well (DJI, etc). So, I am assuming that the APM can be tuned to handle that as well. I am sure it's function of disk loading and prop size with smaller props handling it better because they can react more quickly. I really like my 12x3.8SFs though because of my expected payload weight
I will keep playing with it.
it depends on the space between the downwash columns of air, if the props are too big the turbulence underneath will be much higher, I've tested my quad with 12" and 10" props and there was a huge difference in behaviour, however in my hexa, the props are very close to each other and I can get quick descents with almost no wobble, I believe you are correct and the smaller props demand less torque for faster responses, compensating much faster and preventing the effect.
It also depends on the distance between props. I've had my tricopter set up with arms ranging from 20-40cm long. Descents are definitely more stable with the longer arms. But there are other problems on my tri with the longer arms. I've settled on them being about 40cm and I'm still able to descend pretty well.
I also have a little Quadrixette 40 that has a 40cm mtm distance and I've never been able to get it super steady when descending. I've tried props from 8", 9", and 10" props and all kinds of PID settings and can't get it to descend stably.
Sounds good Randy!
My KK came with 3 bladed 9" props and it did descend rapidly more stably with those than the 11" x 4.7 GemFan 2 bladed ones I have on it now.
Among other things the 3 blade smaller diameter prop represents a more symmetrical aerodynamic load at each motor than the slowly turning 2 blade ones.
You can also hear the noisy chop of stalled blades when you are descending rapidly and that is always a source of asymmetric turbulence and loading. (and also compromises the APM's ability to stabilize).
That having been said I wouldnt go back to the 3 bladed ones for anything.
The GemFans use considerably less power, have higher performance and are much quieter (at least when you aren't descending so fast that they are stalled.)
may be this post and discussion might be helpful ?
On my Hex I have Stab P3.800 and I 0.002 and its really solid. Check out my Youtube channel jrcampen
Looked at the suggested link and it certainly points out some of the limitations of using air pressure for the fine altitude maintenance necessary in close to the ground conventional and multi copters.
An additional problem is that gusts also often result in sharp changes in local air pressure causing inappropriate compensation in alt hold modes.
I'm using Planner 1.1.93 mav 1.0 and with the new config screens I'm not sure about my loiter or yaw settings. First I noticed in section ArduCopter Config that my loiter P=0, I=0 and IMAX 30 but when I go to other section ArduCopter Pids I see other settings for loiter which are 2.4 | .08 | .4 | IMAX 30.
And regarding YAW, for the first time I tried to take off in ACRO mode to try and tune that and it quickly does a fast yaw even though it is very good in stable mode. SO I checked my Rate Yaw and it's .13 | .0 | .002 | IMAX 50
and in stabilize Yaw it is 8 | .01 | IMAX 8
Is this right or is my acro spin caused by something else? I would like to tune acro but the YAW is out of control causing the quad to spin CW. In stable it is ok and YAW is solid so I'm thinking some PID is wrong but the only settings I've changed is stable mode PIDs.
Hi Rui, i did performed erase and reset via Terminal before i upload the firmware. Anyway i will try to recalibrate again the Tx on this weekend and see the outcome.TQ
Great to know and that tells me why my KK tri-copter had the jitters when I attached my key chain camera to it.