I’m testing throttle failsafe and having an issue whereby once the throttle failsafe causes a short FS followed by a long FS, the plane enters CIRCLE and then RTL as expected, however the throttle channel is shutdown to minimum pwm, obviously shutting down the motor.
Strangely, changing the THR_FS_VALUE to 1500 to induce a throttle FS without TX shutdown, actually temporarily fixed the issue, and the throttle channel increased to the expected % for cruise RTL. However after power of & on, the issue is back.
No arming error conditions are present and there’s a good gps fix.
What RC tx and rx are you using? If possible, set the receiver failsafe action to “no pulses”, that way it doesn’t get confused with low throttle. Alternatively follow this: Radio Failsafe — Copter documentation.
I’v upgraded to 4.5. Tx is QX7, receiver is R9M mini. Same result after upgrade.
It appears the receiver is not changing the failsafe method, since changing between no pulses, hold and custom doesn;t produce any difference in how it failsafes, and setting to hold should fail to produce a throttle failsafe.
A workaround I’ve found is to change the servo function controlling the esc to RCinx instead of throttle, this forces the throttle signal to remain as it was before failsafe.
I don;t actually know what the failsafe condition is on my receiver, since changing the mode through the TX should change the setting withing 9 seconds.
maybe this is the problem?
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THR_MIN,0
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i need to set my THR_MIN (IC engine) to somehwere above 0 at a point where the engine won’t stall, because some modes tend to cause the THR to go to MIN 1st, then advance from there.
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ps. You don’t say what kind of engine/motor you have. If IC, then…
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THR_SLEWRATE,100
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…might be too fast for your engine. Some of my engines would be in danger of stalling if throttle is advanced too fast.
(“Shutting down the motor” could be interpreted as stalling the engine OR stopping the electric motor)
That’s definitely worth a try, i’ll try setting to 50. My plane uses an electric motor.
I’m failing to understand why in RTL mode the FC would set the throttle to THR_MIN instead of trying to maintain a cruise speed.
The notes for THR_SUP_MAN says “When throttle is suppressed in auto mode it is normally forced to zero…” Again why would you want throttle set to 0 in RTL mode?
“electric motor” … you can ignore all i said about the IC engine cautions. when i was flying e-motors, i didn’t have a problem when the auto modes would kick in. the motor would still drop to zero momentarily, but was ably to pick up (e-motors don’t stall) and the plane just dipped a little. also, an e-motor can easily take 100% slew rate (unless the ESC is overloaded), so no worries there.
the RTL is an “auto” mode, my experience has been… whenever i switch from one of the interactive modes into an ‘auto’ mode, the throttle will go to minimum and THEN up to the programmed cruise speed. i don’t know why, seems like it’s initiating the mode somehow. I don’t like it at all - it affects IC engines much more than an electric motor. but i set my min throttle to above zero to avoid killing the engine. i’ve learned to live with it.
here’s how you can see this at work with an ic engine… if you have a plane that can take off from the ground by itself, and you have a mission, with an autonomous takeoff, programmed in… taxi out in a manual mode and line up for takeoff; switch to “auto” mode and watch the engine drop to min throttle 1st, then accelerate to your takeoff throttle from there. if your min is set too low, your engine will die at this point.
an electric motor, in this case, will not show the behavior because you will probably drop the throttle to zero before switching to auto anyway. and e-motors have no problem sitting at zero throttle before ramping up. but, if you want, DON’T drop the e-motor throttle to zero (keep the prop spinning) before switching to auto mode, then the behavior will become apparent (if your min throttle is zero).
however, i am not sure this is your issue (i cant look at your logs - my fault), since this should not cause an RTL failure.