ACRO bug (fixed in 2.9.1b): while doing flips in ACRO mode, if you switch to Stabilize while inverted your throttle will go to minimum. To regain throttle control you need to switch back to ACRO then back to Stabilize again (i.e. switch to stabilize twice). You never lose control of roll/pitch/yaw.
Loiter/AltHold/Auto/RTL bug: if you switch into these modes with throttle at zero motors will go to minimum until you raise the throttle.
Auto mode altitude bug (fixed in 2.9.1b): setting a waypoint altitude greater than 320m over home altitude may wrap around and instead be interpreted as a low altitude.
ArduCopter 2.9 is now in the mission planner and the downloads area!
The major improvement is we use inertial navigation to improve altitude hold. This increased reliance on the accelerometers means you must do some additional set-up before flying:
1. Perform the new accelerometer calibration in the mission planner (video). The auto-trim metho has also changed (video).
2. Add vibration dampening foam between your frame and the APM. Some suggested materials: DuBro, gel, hk foam.
3. If upgrading from 2.8.1, modify the throttle and altitude PID values:
- Increase your Throttle Rate P, reduce I to zero, increase D
- Increase Altitude Hold P, reduce I to zero
- Tune Throttle Accel P and I terms but try to keep P about 1/2 the size of I
Here is the list of major changes (a more detailed list can be found in the release notes):
- Alt hold using inertial navigation (Leonard, Randy, Jonathan)
- AUTO_VELZ_MIN, AUTO_VELZ_MAX parameters control the max climb/descent rate for the autopilot (cm/s)
- PILOT_VELZ_MAX controls max climb/descent rate for the pilot (in cm/s)
- Landing improvements (Leonard/Randy). Copter will descend to 10m or until an object is sensed with the sonar. Then slows to 50cm/s descent (speed can be adjusted with LAND_SPEED parameter). (video).
- Surface tracking with sonar (Randy/Leonard). Copter will attempt to maintain current distance from objects in front of sonar regardless of altitude. Only used in alt-hold and loiter, not used for missions. Sonar can be enabled/disabled with CH7 switch. (video)
- Failsafe improvements (Randy/Craig/John Arne Birkeland) including bug fixes, additional check for PPM encoder failure and implementation of battery failsafe. Set-up instructions are here.
- Mediatek gps driver accuracy improvements and use of SBAS [Craig]. Instructions on upgrading your mediatek to firmware 1.9 are here.
- Traditional Heli improvements (Rob) including (a) bringing heli code back into the fold, (b) enabled rate controller (previously only used angle controllers). (c) fix to rotor speed controllers - now operates by switching off channel 8. (d) allow wider collective pitch range in acro and alt hold modes vs stabilize mode (e) bug fix to allow collective pitch to use the entire range of servos
- Acro trainer (Leonard). Copter will return to be generally upright if you release the sticks in acro mode.
- ACRO_TRAINER : set to 1 to enable the auto-bring-upright feature
- ACRO_BAL_ROLL, ACRO_BAL_PITCH : controls rate at which roll returns to level
- Camera control improvements (Randy/Sandro Benigno): (a) AP_Relay enabled for APM2 (b) Trigger camera with CH7 or DO_DIGICAM_CONTROL command (c) Allow pilot override of yaw during missions and fixed CONDITIONAL_YAW command.
- PPM sum support for transmitters with as few as 5 channels (Randy/Tridge/John Arne Birkeland).
- Performance and memory useage improvements (Tridge).
As per usual 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.
Special thanks to our testing team lead Marco and the dedicated bunch on the 2.8.1 release thread who put their copters at risk while testing the pre-release version. Some of their videos are here: 1 2 3 4 5 6 7 8
Please feel free to report issues you find in the discussion below and/or add them to the issues list.
Replies
I've been struggling with a slow X Y oscillation on my Quad in Loiter mode. It is continuous and does not escalate or diminish and would only be a few degrees up/down.
I suspect noise after spending countless hours (actually weeks) trying to tune it out with PID's.
Stabilise is solid, Alt Hold is solid. Blades are APC & balanced. Mega 2.5 board is mounted on standoffs made from silicon fuel tube. Firmware is 2.9.1.
If someone can take a quick look at the LOG file and confirm my suspicions it would be greatly appreciated. From what I can see it's a 10 on the Reichter Scale :-(
Thanks in advance.
2013-03-10 14-08-30.tlog
My friends Futaba over time finds the signal rage gradually decreases. He now looses signal after 100m altitude where previously 900 was no issue. Why wold that be? This is now the second Futaba RC he found doing the same thing.
I am stuck at the moment like a few who had crashes (including myself on two occasions) secondary to accuracy / positional issues related to the GPS filter routine in 2.9.1 used in conjunction with the MTK GPS v1.9. This problem results in auto and RTL modes being unrelaible if the MTK with v1.9 is being used instead of the LEA Ublox GPS. Typical signs are failure to stop at waypoints, erratic behaviour e.g in GPS dependent modes like loiter if a delay in GPS data is experienced and inability to return home to launch point. In my case it was some 70 meters short.
So rather than risk loading v1.9 on my spare MTK and using this with 2.9.1 I want to find the best way to revert temporarily to 2.8.1 and use the standard v1.6 library in the code with another new MTK I have on this version.
When I receive my new Ublox GPS I will go back to 2.9.1. My understanding at the moment is there is no work being done to fix this problem with 2.9.1 and the v1.9 MTK GPS. It is certainly not even posted as a warning at the start of this thread which is a little disappointing. Do not get me wrong 2.9.1 is a significant step forward and the ALT Hold in particular with good tuning and minimal platform vibration is superb and a testimont to the good work being done by the developers and beta testers. I will miss 2.9.1 while I have to fly on 2.8.1 to avoid my copter flying away and not being able to RTL as I want to continue using auto mode.
MAX YAW RATE
I was flying with a camera and found the YAW rate in AUTO to be too high. If there a way to cut the max yaw rate in half for AP missions?
?
I am fairly happy with my vibration but am still trying a few improvements.
I have watched a few videos of drummers using the moongel and they just stick it on the drumskin. As my APM is already on thin foam and I dont want to un-stick it again, I am thinking of just sticking a piece of moongel to the top of the apm, perhaps with a coin or something on top of that. Easy test.
This thread is very long and I cant seem to find a definitive answer to this-
If am using a normal PWM RX is there any point doing the PPM upgrade thing?
Developer suggestion-
Is it possible to distinguish vibration from normal control accelerations? If so, what about a self adjusting filter value. I am concerned that a low vib copter with high tuning may become unstable if something comes loose. Even in forward flight the non-axial flow into the props seems to cause vibration.
I had my first loss of control crash with my 2.9.1 APM2.5 today. Can someone in the know please have a quick look? Basically my radio inputs stopped working and at that point it switched itself from Alt hold into Loiter, then after being unable to regain control or get any response using my RTL mode switch, I powered the TX off which initiated RTL (and then proceeded to crash into the house on the way down after returning (my fault, I didn't power it on far enough away).
I haven't upgraded the ppm encoder firmware, but I'm not sure if this affects it? I just tested my TX now, and it appears to be working as far as I can see.
The thread is here: http://diydrones.com/forum/topics/loss-of-control-crash
And my tlog is here: http://www.droneshare.com/view/dobyrdz
Thanks
Hi guys,
So I've had some vibration issues that I thought were really related to a bent motor shaft from about a year of service and crashes. I definitely have a motor that makes a whistle while it flies. The new motors are on order and not here yet, so I decided to see if better vibration dampening for the APM could cover up my problem. In short, yes. I switched from 1/4" high quality helicopter gyro mount tape to the a version of the earplug method. The before and after results are posted below. Now I've got stock settings on alt hold and mpufileter to 20 hz. Unbelievable altitude hold. I'm going to do a blog post tonight outlining the VR reduction setup. I am posting this just so that we can get an idea of what kind of results just a 5 minute earplug job can produce.
Special thanks to Randy for the diagnosis help,
Ted
please help me
im try test arducopter with chinese ublox 6m (without 3dr config file)
its detected and show 3d fix and correct lat & lon (but hdop and satcount wrong)
but in loiter mode quadcopter do not resist to the wind!
at the log line 2148 am enable loiter mode but below ntun mesages show zero in lon & lat error
i try to find in source code howto satcount or hdop affect to alt_hold and I find nothing
2013-03-03 18-25 2.log
Is -5 to -15 still considered acceptable for Z Accel vibration when running 2.9.x? After balancing props and motors I am within that range but just barely. I have not yet done anything to isolate the APM from frame vibration.
Hi guys,
I posted this in the APM 2x forum but no response, thought I'd hop on a thread with a lot more eyes on it. Recently upgraded to 2.9.1 and now when I use altitude mode (or guided or any altitude controlled mode) and move the quad at a moderate pace it climbs like crazy. As soon as it stops it figures things out and then descends. If I disable throttle accel it seems worse. Any ideas?
Here is the original thread with logs:
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