I've been flying very close to my TX while I get the hang of AC2, now I'm trying to configure failsafes so I can go a little further without the threat of falling out of the sky.
My setup is a quad, AC 2.0.50 with Optima7 RX and Aurora 9 TX, APM2580+Oilpan.
Bench Test:
1. Stabilize mode, quad is tied down to level surface, give it minimal throttle to spin props. (Normal startup). Moved the quad about 15m from GPS lock "home", but same altitude.
2. Kill TX power.
3. Throttle drops to zero for 1 second or so.
4. Throttle restores to previous level. Mode remains stabilize.Never goes into RTL. Waited about 40 seconds.
5. Restore TX, all is good after that.
- During that 1 second of no throttle the quad might be doomed.
- I set mode 4 to RTL + simple, however the quad doesn't go into RTL, it remains in stabilize.
- Yes, GPS lock was set before arming.
I considered using the Optima 7 failsafe, but I would have to select levels for the channels (default is 1500). Since i fly both with and without camera gear (FPV + TX + goPro) I'd have to reset the failsafe throttle value based on weight.
Per this post there's a short and long failsafe mode, but I don't see these kick in.
http://diydrones.com/forum/topics/change-failsafe-modes
I don't want to test in the field and crash, so these quick test results might be compromised by my tie-down-and-test methodology. Any advice on the best failsafe setup ?
Replies
I managed to fix this issue once with my Optima7 RX by setting APM mode 4 to RTL, then programming the RX failsafe value to the lowest value.
I've since upgraded to EzUHF, and the RX functions a bit differently. The lowest value I can get with my Aurora 9 TX and ExUHF on the throttle (with full EPA down) is 1003. I set the following values:
THR_FAILSAFE = 1 (changed from zero)
THR_FS_ACTION = 2 (default)
THR_FS_VALUE = 1040 (changed from 975)
Then through the Arduino relax patch IDE I added
# define THROTTLE_FAILSAFE ENABLED
I didn't need to do anything to events.pde (line 21 or so) as that code was already enabled. I then successfully programmed the board.
I then backed the EPA on my TX CH3 to normal and my lowest value now with power to the RX is 1080. Value with the RX off is 900.
Finally to test I strapped my quad down to the bench, started it up, waited for GPS lock, then armed and put about 15% throttle. If I hid my TX mode switch it goes to loiter (because it's already RTLd in effect). In stabilize mode, if I cut TX power, the motors stop. CH3IN shows 1003 with the TX off, but motor stop = certain crash.
I'm assuming that the FAILSAFE just isn't kicking in. Must have done something wrong... any suggestions ?
I'll enclose the log file in case someone wants to have a look. I repeated the TX fail test again at the end, so check backwards, I also did a UBEC brownout test in the middle there.
2011-12-28 11-18-34.tlog
I think that the optima 7 is in hold mode by default on all channels. Did you check the radio values in the CLI or Mission Planner (raw sensor view, radio subwindow) when you cut your transmitter ? IS it ok ?
You must check this first and see what your receiver is doing when you cut the transmitter.
There is a SW failsafe in Arducopter, but it's not enabled by default.
in APM_Config.h write this:
# define THROTTLE_FAILSAFE ENABLED
If your throttle drops below 975 it will trigger failsafe and do RTL.
You must also uncomment line 20 of events.pde so it looks like this:
set_mode(RTL);
motor_auto_armed = true; // very dangerous!!!!
I don't enable it because you could trigger it accidentally by shutting off your transmitter and that would be a "bad thing."