I have a small problem with failsafe. It activates RTL when I turn off the R/C according to the logs. The problem is that the copter starts to violently gain altitude, even so much so it starts to vobble. I left it alone up to 50:ish meters, but it just kept going.
When I activate RTL-mode when flying normally, the copter reacts in a slow and controlled manner and goes home, no problem at all.
Any clues to what might be happening here?
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Here is the log of my most recent attempt. I had stab and loiter as my two modes, and RTL as the failsafe.
RTL is activated two times, both with a very heavy throttle as a result.
I do not understand much about the logs yet. I assume Nav Throttle in CTUN is the signal which the controller calculates when in loiter or RTL-mode and adds to whatever throttle out was when the mode was activated.
The baro alt and climb rate-parameters look very agressive on the two times I tried failsafe. When looking at the Nav Throttle it looks like it is trying to use less throttle about halfway in, but that it is not enough.
What parameters should I play around with to get a lower initial Nav Throttle increase when failsafe RTL activates, and how much should I change them as a first go?
My guess is that I should play with the "Thrust Rate" PID, perhaps change P to something alot less than what it is now. Perhaps set it to 0.2 from 0.3?
2012-11-03 10-26 17.log
2012-11-03 10-26 17.log.gpx
2012-11-03 10-26 17.kmz
Kim,
Thanks for including your parameter list. Not quite as useful as logs but it still allowed us to identify the problem. It looks like you do not have the throttle failsafe enabled. You can check it by looking at the parameter called "THR_FAILSAFE" or using the mission planner's FailSafe screen (see below).
Each tx/rx is different but on my futaba there is a set-up screen in the transmitter itself which allows me to set channel 3 as the failsafe channel and when i do that I can also make it output about 960. The value that it outputs on channel 3 must be below the THR_FS_VALUE parameters value which by default is 975.
So first do the rx/tx failsafe set-up, then check it's outputting <975 through the mission planner's configuration, failsafe screen. Then set that "Throttle Failsafe" checkbox on that same screen.
One word of warning about the throttle failsafe though..you need to be careful upon landing your copter after a flight to disarm your motors before turning off your radio. If you don't do this..ie. if you turn off your radio first, the failsafe will trigger and your copter may take-off in RTL mode.
Hope this helps.
Which version of APM are you flying?
Please post your log files so we can analyse them.
Sorry for bumping, but you don't have any ideas or suggestions?
Are there any parameters which is used in failsafe RTL but not used in normal RTL which I could take a look at?