Warning #1: an issue has been found with Tower's Pause button which can cause the vehicle to fly to an old position if the vehicle has not sent a position update to Tower in some time.
Warning #2: Copter-3.3.2 fixes a bug found in Copter-3.3.1's desired climb rate initialisation which could lead to a sudden momentary drop when switching from Stabilize or Acro to AltHold, Loiter or PosHold.
Warning #3: Copter-3.3.2 fixes an issue found in Copter-3.3.1 which could lead to hard landings in RTL or AUTO if the WPNAV_SPEED_DN was set too high (i.e. >400 or 4m/s) and/or the WPNAV_ACCEL_Z was set too low (i.e. <100 or 1m/s/s).
Warning #4: a bug was found in Copter-3.3 which could cause a sudden crash if you abort a Take-off initiated from a ground station. Video description is here. The bug is fixed in Copter-3.3.1 so we recommend upgrading.
Note #1: AC3.3-rc8 corrected a long standing bug in the HDOP reporting. HDOP values will appear about 40% lower than previously but this does not actually mean the GPS position is better than before.
Note #2: if upgrading from AC3.2.1 the vehicle's accelerometer calibration needs to be done again.
Note #3: set SERIAL2_PROTOCOL to "3" and reboot the board to enable FrSky telemetry like in previous versions.
Note #4: the wiki will be updated over the next few weeks to explain how to use the new features
Copter-3.3.1 is available through the mission planner. The full list of changes vs AC3.2.1 can be see in the ReleaseNotes and below are the most recent changes since AC3.3.
Sadly this version (and all future versions) will not run on the APM2.x boards due to CPU speed, flash and RAM restrictions.
Changes from 3.3:
1) Bug fix to prevent potential crash if Follow-Me is used after an aborted takeoff
2) compiler upgraded to 4.9.3 (runs slightly faster than 4.7.2 which was used previously)
Changes from 3.3-rc11:
1) EKF recovers from pre-arm "Compass variance" failure if compasses are consistent
Changes from 3.3-rc10:
1) PreArm "Need 3D Fix" message replaced with detailed reason from EKF
Changes from 3.3-rc9
1) EKF improvements:
a) simpler optical flow takeoff check
2) Bug Fixes/Minor enhancements:
a) fix INS3_USE parameter eeprom location
b) fix SToRM32 serial protocol driver to work with recent versions
c) increase motor pwm->thrust conversion (aka MOT_THST_EXPO) to 0.65 (was 0.50)
d) Firmware version sent to GCS in AUTOPILOT_VERSION message
3) Safety:
a) pre-arm check of compass variance if arming in Loiter, PosHold, Guided
b) always check GPS before arming in Loiter (previously could be disabled if ARMING_CHECK=0)
c) sanity check locations received from GCS for follow-me, do-set-home, do-set-ROI
d) fix optical flow failsafe (was not always triggering LAND when optical flow failed)
e) failsafe RTL vs LAND decision based on hardcoded 5m from home check (previously used WPNAV_RADIUS parameter)
Thanks for your testing!
Replies
Good advice!
I just read my post this morning, and it makes the landing detection sound bad. But I should mention, my flying area isn't completely level, and I'm often trying different props or flying without my camera, etc, so I'm usually causing my landing problems. Controlled landings with a tuned copter on level surfaces work as they should.The motor stop switch saves me the rest of the time.
Scott, Richard,
honest feedback is fine.
If you guys have logs we can have a peek as to what's going on. As Richard describes there is a moment when the pilot throttle passes 25% (or 1/2 of mid throttle) where we suddenly turn on the attitude controller. Leonard and I have a patch that attempts to smooth out the transition but it's a AC3.4 fix.
Hi Scott
What you describe does sound like what is happening to me. On arming, and at first spinup, It sometimes jumps into the air before I am ready, or it may tip over immediately on arming.
There is that critical moment when the attitude of the copter is in its side that things can quickly go very wrong as the copter attempts to right itself by going to full throttle. There probably will not be enough time to reach for a cutoff switch to stop a out of control multi rotor before it could easily do bodily harm if you (or others) are in its path.
Perhaps some logic code could detect that situation and shut down automatically. That would be a very good safety enhancement worthy of adding to the code.
On Arming you can control how the props spin. In my personal case I regulate that to the lowest possible velocity that the combo ESC/Motor has a steady spin and it's low enough that no propulsion is generated.
https://youtu.be/ec6srDAq2EE?t=22s
Use MOT_SPIN_ARMED to control how fast the props spin on Arming. Some have the Mot_Spin_Armed disabled, but I really like it because the speed is not enough to cause damage
Hi Scott,
I love it too :)
Hi
![3702590906?profile=original](https://storage.ning.com/topology/rest/1.0/file/get/3702590906?profile=original)
Besides what has been said by Trent Russell there's something very strange on your vibration log that occurs right after you said you changed to PosHold. If you see the clipping that jumps at that time, I would say that something physical came loose and from that point forward the copter was trying really hard to keep up.
I know that now might be almost impossible to trace back where the physical fault might have occurred but look carefully at what might not be crash results.
Hi! This is a question specially for Leonard and I think and the answer might be a good addition to the Wiki.
Let say I have a copter that I know the PID should start at 10 for stabilize Pitch and Roll and 0.25 for Rate Pitch and Roll. I remember that those values are near the previous ones that I had on the same copter but I had to clear the eeprom and I forgot to back up :-(.
Does it help and speed up the process if I start with that?
Maybe this can be extended to a second autotune if the values that are setted in a previus one are not too accurate?
Thanks so much for the help
Hi Bernardo,
Yes you can manually add those values and Autotune will start there. It will also speed the process up considerably. That is why a second Autotune will run significantly quicker than the first.
The main reason I run a second autotune after I successfully finish my first is because poor tune on one axis can mess with the results of the other axis a little. The second Autotune runs relatively quickly (I always wait for good conditions for the second tune) and gives me confidence I have close to the optimal result.
This is great info! I did not thought about the second autotune right after the first one but is a logical thing.
I know the default PIDs are really conservative (or maybe they are thought for small overpowered copters) but I have a large octa and even though it flies at 30% throttle, I have to almost double the original ones.
Please consider adding this info in the wiki. Many people like me sometimes makes a clean install on a copter and we almost know what values are optimal and we need autotune to polish the numbers.
Thanks for your great work