Failsafe customizable settings

Can i customize pwm of every channel when air unit goes onto failsafe? It looks like it outputs very low pwm when in failsafe on each channel and i can’t change it.
Something like “stick to these values when in failsafe”.

thanks,

Corrado

I don’t think you can pre-set failsafe PWM values as there are no parameters for that

Depends on what failsafe you have triggered, you can regain the radio control:
https://ardupilot.org/copter/docs/parameters.html#fs-options-failsafe-options-bitmask

Probably my question was not clear, i retry reformulating it. I would like to know what is the sbus status for each channel emitted by the air unit in case the link is lost. I would like to know if the status of each channel emitted by the air unit in case of fail safe is customizable. For example, in case of radio fail safe i would like the air unit to emit 1500pwm on channel 7 and 8.

hope it is clear now.

Corrado

If the sbus disconnected, the sbus will freeze and stay at what it received most recently.
Eg: If you have changed ch7 to 1500pwm before losing the link, it will stay at 1500. There are no way to change on neither herelink side nor ardupilot side, as far as I know.

You may try to set up a lua script to detect failsafe status, then assign new pwm value to channels under such situations.

So if for any reason ground unit switches off during a fast forward, the copter will go into rtl with elev at 2000, and i’ll end up waiting for the disaster as soon as it changes from rtl to land on final stage, where full elev will kick in again and nothing to do for me but wait for the impact.

@philip/@Alvin is that true? How can we avoid it?

You could disable elev and ail input during land with LAND_REPOSITION = 0 but than if you need to reposition during land you can’t :slight_smile:

I think it is hard to imagine that the developers did not cover this! Why isn’t any input ignored when throttle failsafe is active?

You could even set RTL_ALT_FINAL to something like 10 meters so it doesn’t go into land but i am not sure if it stays there in rtl or it switches to loiter making things even worse. Even if it doesn’t go into loiter and it just stays there, it is only a matter of time before battery go flat and it falls. All of this if the radio doesn’t come back before.
Don’t know why it is like that on herelink, but on other radios you can tell the system where to put every single channel during failsafe and have the copter act exactly as you wish, not with herelink :slight_smile:
Don’t get me wrong, it is a great system, it just lack some basics here and there.

Ok, thank you!
What I do not understand is why Arducopter does not ignore any input as long as radio failsafe is active. I find it very hard to imagine that it is designed like that. I will test that tomorrow.

Maybe it does, it didn’t during our tests. It could be i missed something during setup, so i am very curious about your findings. Will be really glad if it does work as expected.
Maybe things changed in 4.0 and now if failsafe bit goes up than ardupilot ignores all channels input. Hopefully it is like that.

I checked from the Mission Planner and the RC channels do freeze if I unplug the RCIN.
However, the autopilot will detect the radio failsafe.

I don’t get why are you worrying about the failsafe RC input so much. Once the RC failsafe is triggered, the autopilot should be able decide what to do by itself, according to its failsafe setting
For example, RC don’t have any control during RTL:
https://ardupilot.org/copter/docs/flight-modes.html#overview

So if for any reason ground unit switches off during a fast forward, the copter will go into rtl with elev at 2000

therefore this will not happen

Arducopter does not ignore any input as long as radio failsafe is active

I think ardupilot does ignore RC input as radio failsafe is active
Arducopter wiki page did not mention this, but in arduplane wiki:
https://ardupilot.org/plane/docs/apms-failsafe-function.html#throttle-failsafe

When failsafe is entered, all RC inputs (except throttle in the case of throttle initiated failsafe), are ignored as the autopilot takes its failsafe actions.

About HighFreq71’s case

Maybe it does, it didn’t during our tests.

Can you share the log from this flight so that we could have a look?

Ok, thank you for clarifying, I also looked in the docs yesterday and could not find anything, neither in the cube docs nor in the Arducopter docs. I find it very hard to imagine that such a behavior is implemented.

I will try it anyway today, maybe it is a wrong configuration. @HighFreq71 if you send me you’re parameters I can have a look whether there is a difference between yourse and mine.