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!).
How does MuMetal compare to Permalloy? Permalloy is easy to get.
I think a sandwich of aluminum and MuMetal would make a good shield. The aluminum on the bottom would block some of the rotating magnetic field, and then let the MuMetal take the static field.
I've got a great source for mumetal - they are sending me loads of sample thicknesses this week :)
I'll report back with results.
Just did a little research on MuMetal and Permalloy.
The biggest problem is that they will in fact significantly reduce the signal strength of the Earths magnetic field at the magnetometer (and are often used to produce just that effect.)
This means they would need to be far enough away from the magnetometer for this effect to be minimal.
From what I can see, keeping the magnetometer an adequate distance away from significant static magnetic fields is the best solution to that problem.
As for the moving magnetic fields or RF interference, both Aluminum and more conventional Faraday style shielding (Steel or copper) provide potential for benefit without negative side effects.
Aluminum has the advantages that it dampens slow moving electro-magnetic fields but is itself non magnetic and it reflects higher frequency RF. Increased thickness somewhat increases effectiveness on electro-magnetic fields.
Basically Aluminum can be an excellent shield for the GPS and is at least somewhat useful for the magnetometer.
Thanks for all the great input regarding this.
In the case of GPS flakiness, a microwave level interference problem, the aluminum seems like it is pretty much the solution because of the way it attenuates, but for the magnetometer in particular, Mu Metal should bock any stray local static magnetic field.
In fact, Mu Metal is so effective I am a bit concerned that if it was too close to the magnetometer it might interfere with its own detection of the earths magnetic field.
I do not know if this is a problem, but it probably needs to be clarified.
Easy to do with a test, so:
I am going to get some MuMetal and give it a try to see what happens and will look into "Permalloy".
I like the sandwich idea with the aluminum.
Yup, I'm going to test this all out, samples on their way. My initial plan is to encase or at least shield the esc's, the motor wires and the battery, and leave the APM in open air, all bar the tupperware... We are looking to block interference from the power circuits here, not stifle the APM.
Another reply deleted... is it just me?
I'm using Chrome, I wonder if that's the problem?
Anyway, my thinking is that a flat sheet of MuMetal, >1" below the APM will block the interference from all the power bits, and probably the vertical component of the mag field, while leaving the XY component of the earth's mag field unchanged? I guess we'll see.
Dave, about suspending it on a stick, I've had good luck putting it on the tail in the heli. I'm getting really good mag numbers now. Putting it up on a stick is kind of an inelegant thing to do for a quad though. I wish there was better way.
I've bought mumetal, and first impressions are: don't use it, it's worse than nothing! With the mumetal under APM I get almost plain mag heading:
I recalibrated the compass after putting the mumetal sheet (only static calibration, I don't have telemetry). It's not grounded. I have automatic compass declination enabled.
I think the problem is as Gary commented that my compass is too close to the mumetal shield.
I really think the best approach is the used by dji: keep compass and GPS away from noise. Maybe I'll use the naza GPS mount and I'll try to put the APM1 compass and GPS there.
Hi Gustav, I have the same GPS-Lock issue because of interferences and I want to put a shield (aluminium or copper) between APM and power board.
Would you please explain how to ground the shield? I think connecting a cable to some ground, but which one? 12V from LiPo or 5V from ESC/BEC or from the UBEC which is powering the APM?
What airframe? Pictures?
To point out, I work in the RF field, and manage Radio and TV transmitters from 5W to 25 KW.
We are also running some sensitive low power receiving type equipment, on the same sites!
And we found there is no one solution to fit all :-(
On to RC and APM's
Bottom line is, make sure your components like ESC's, UBEC's have the proper toroids, as close to the actual device, as possible.
Try to twist all wires carrying DC.
Try to separate these devices as far as possible from stuff like GPS antennas.
On my fixed wing drone, I extended the wiring, the GPS is way behind the wing now.
I have a stock jDrones quad, followed the recommended build, no problems with GPS, am running Spektrum telemetry, and xBee.
There is no easy way to just slide a piece of metal in between stuff, ground it (preferably the ground point on the Power Distribution Board), and make it work.
If the grounding wires isn't less than about an inch in length, it is pointless at radio frequencies.
Butt even after 32 years in the field, we still call RF "Black Magic", so you might be lucky with just a sliding some foil between the different devices, and connect that to the PDB negative :-)
any photos of the board and setup? You must make sure wires have chokes and shields and well away form the mag. Also the Xbee needs to be well away form this as well because ti will send the mag haywire