After months of testing AC3.1 is finally available in the Mission Planner and GitHub.
Warning #1: If the vehicle is left landed (but armed) while in AltHold or Loiter mode for more than a few seconds, the vehicle may suddenly jump into the air the moment the pilot raises the throttle above zero. The reason is the baro altitude may fall while the vehicle is sitting on the ground. In AC3.2 this bug is fixed because we reset the target before take-off.
Warning #2: Motors will spin (slowly) by default as soon as the copter is armed! You can switch this feature off by setting the MOT_SPIN_ARMED parameter to zero.
Warning #3: if you see "Bad Gyro" on the HUD then you may have a blown 3.3V regulator. See this thread for details.
Warning #4: if you use a sonar set the SONAR_GAIN parameter to 0.8 or lower
Warning #5: Trad Heli users should now connect their main rotor ESC to APM's RC8 output
Warning #6: Trad Heli BUG causes loss of collective control in ACRO mode if swash type set to flybarred (i.e. not flybarless). Will be fixed in AC3.2.
The major improvements over AC3.0.1 are (full list here):
1. Pixhawk support (Tridge & PX4 development team)
2. Autotune of Roll and Pitch gains (Leonard/Randy)
3. Drift mode (Jason)
4. Improved Acro (Rob/Leonard) and new Sport mode (Leonard)
5. Arming, Take-off, Land in Loiter or AltHold
6. TradHeli improvements (Rob) including:
a) support for direct drive tail rotors
b) smoother ramp-up of main rotor
c) reduced collective for better control in stabilize mode (STAB_COL_MIN, STAB_COL_MAX params)
7. Support for SingleCopter (Bill King)
8. Performance improvements resolve AltHold troubles for Hexa & Octacopters
9. Safety Improvements:
a) GPS Glitch detection (Randy)
b) Motors spin when armed (Jonathan Challinger)
c) crash detector shuts off motors if copter flipped for 2secs
d) batt failsafe option to RTL instead of LAND, gps failsafe option to trigger AltHold instead of Land
e) more pre-arm checks of inertial nav speed,
10. Bug fixes:
a) optical flow working again (although performance is still not great because not integrated with inertial navigation)
b) ROI working (use DO_SET_ROI command)
How to upgrade:
Click on the MissionPlanner's Initial Setup >> Install Firmware screen. The version numbers should appear as "ArduCopter-3.1", then click the appropriate frame icon and it should upgrade as per usual.
Special thanks to Marco and the many beta testers on the AC3.0.1 thread who put their copters at risk during the testing of this new version and uncovered many problems so that you don't have to! Here are some of their videos: loiter in wind, patio sonar, autotune, autotune2, roi, beach, acro, vrbrain, tricopter, train spotting, radio failsafe, the tree, double loiter
If you haven't seen it recently, please check out the ArduCopter wiki.
Feel free to post comments below and we're going to use the new APM Forum for support issues so please post your support requests there.
Replies
Petr,
This is very likely to be a vibration problem. The rocketing into the air is the classic symptom. There's a wiki page here which shows how to check using the dataflash logs.
Hi Randy,
Thank you for your answer. The vibratitons were the first thing I checked and it seems to be OK:
Regards Petr
Petr,
Looks like the PILOT_VELZ_MAX is set to 32000! Normally around 250 is good.
Randy ,
Thank you for the solution. I have checked x-times all the parameters about altitude, power, PIDs.. but didn´t thought that this parametr it could be.
It was definitely the PILOT_VELZ_MAX. Now pixhawk flies great. I need to precise the tuning a bit but I feel it will be a great multicopter again.
Thanks very much :D
this is the Best i can do to illustrate how the Quads are Flying and whats happening in ALT HOLD. First Video, for the first 3 minutes, i Fly the X650 back and Fourth, trying both ALT HOLD & DRIFT. As you can see by the Vibration graph i am pretty much fine there. DRIFT performs better than ALT HOLD but instead of Descend, it Ascends which i am find with. its a large movement upwards just like in ALT HOLD as it Descends. teh ODDEST thing i noticed on Both F450 and X650, if i fly it in Reverse in ALT HOLD, it stays on a direct line and never Sinks like it does in forward motion.
Videos: X650 FW 3.1.1
https://www.youtube.com/watch?v=Otg0BaDbKW0
F450: FW 3.1.5
https://www.youtube.com/watch?v=JAtgAuQcPAI
Here is Vibration Graphs: X650 Is First,
F450 next,
i will do a Second post to upload logs
Here are my Logs X650 First, F450 Next
X650 Has: 14.7 Props, X650 motors 780KV, 3S battery 800mah
F450 has: 11.7 Props 2212/ 920 KV motors
X650 Log.log
F450 Log.log
if you are looking at the logs, i agree, but the video tells a different story. what i want to know is why doesnt it descend when flying in reverse? thats gonna drive me crazy!! But in the video you can see the quads go forward on a sloped path, descending. i had to stop their forward motion several times so they wouldnt hit the ground. near the end of both videos i raise the quad up higher, then switch to ALT HOLD, and it just drops down by the time it gets out to the tree. ia m beginning to think i will never figure this out. :( thanks for responding!!
Yes they both correspond to the logs, what you are viewing is the flight that made that log. I tried 2 different altitudes, start from 8-10 feet, then one from about 15 feet. same result, but it doesnt happen in reverse. i am thinking of just flying my quads in reverse from now on in ALT HOLD :P
I haven't looked through all the comments or at the logs but there are a few alt hold issues that we commonly see:
1. slow descent while in Loiter or AltHold caused by the pilot leaving the throttle stick below 40% (i.e. below the deadband). This sounds silly but it happens a fair bit surprisingly. You can see if this is the cause by looking at the CTUN message's ThrIn.
2. temporary drop in altitude when the flattening out after high speed forward flight. This is caused by an aerodynamic effect of the copter. When the pressure on the top of the copter is higher as it's flying forward and then suddenly released when it leans back. There's no much you can do about this except try to redesign the aerodynamics of the copter. If the pressure is balanced between top and bottom of the copter the effect is greatly reduced.
3. barometer drift caused by weather changes. This will be different on different days though.
ThrIn shows at or about 560-600 solid on the value graph. Loiter is rock solid, stays put every time at about 10 feet.
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