Change the mode WP defaults to when there's no loaded mission

[skorokithakis]

Currently, WP mode acts like full manual/acro when no mission is loaded. That is a dangerous default, as forgetting to load a mission will switch the craft to full manual instead of full auto. Having poshold/althold as a default would be much saner, as then the failure would be "my craft is unexpectedly holding its position" instead of "my craft is unexpectedly flying towards people".

[simtcrom]

I launch the quad and enable pos hold and then enable WP.
So any point WP is failed or cancelled, quad is in pos hold.

[skorokithakis]

That's a good workaround, I didn't know WP worked in poshold. However, I think it would be best if this problem were fixed as well, as I'm sure it's cost other people a crash too.

[stale]

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[shellixyz]

I think that if the switch to the newly selected navigation flight mode is not possible (high PDOP, no WPs loaded for WP mode) the FC should leave the last flight mode enabled. For now it will switch to rate mode (ACRO).

[stronnag]

My recollection is that is does leave prior last flight mode, at least for no WP loaded.

[skorokithakis]

I think that if the switch to the newly selected navigation flight mode is not possible (high PDOP, no WPs loaded for WP mode) the FC should leave the last flight mode enabled. For now it will switch to rate mode (ACRO).

That is suboptimal. When we switch to WP, we expect the craft to be completely self-controlling, so any mode that expects input might lead to a crash. The only reasonable fallback for this is POSHOLD, where the worst that can happen is "why isn't it moving" versus "why is it killing people".

[shellixyz]

@stronnag Not in my experience. I don't mix angle and navigation modes so when switching to a navigation mode if it doesn't engage it is like no mode have been enabled so it is back to acro.

@skorokithakis If it doesn't switch to WP it could be that the PDOP is too high or you don't have enough sats. Then it won't enable POSHOLD anyway so back to square one. At least if it doesn't change mode it shouldn't kill anybody because you can expect it.

[skorokithakis]

@shellixyz In the case that PDOP is too high or I don't have enough sats, it's fine if it tries the next most stable mode (ANGLE?), but if it does, there's no reason to not enable POSHOLD. Basically, the craft should always do the closest thing to what I meant, with consistency having a lower priority than predictability.

[shellixyz]

POSHOLD needs GPS too. If WP doesn't engage because the position is not healthy it can't engage POSHOLD either. I guess it could engage ANGLE instead but I find it more logical for it to stay in the previous mode.

[skorokithakis]

I know, I'm saying there's no reason to throw the baby out with the bathwater and say "because we can't POSHOLD with no GPS, we shouldn't POSHOLD when we have GPS either". I think the vast majority of people would expect that, when they trigger WP and it fails, the craft would stay in the mode that's closest to full-auto.

I think it makes much sense to say "You switched to WP intending to fly a mission, but since you forgot to load the mission I'm just going to stay in ACRO even though you took your hands off the sticks".

[shellixyz]

The problem is that you should be able to know what to expect. If you don't know the position health you won't be able to know what mode it engages and that's even worse. If it can't engage a navigation mode and stays in the previous mode you at least know what mode you're in. If you are in angle mode, try to switch to WP and it doesn't engage it would stay in ANGLE. If you were in ACRO it would stay in ACRO. etc.

Also if it fails engaging a navigation mode the aircraft should beep angrily (for LOS) and also display a message on the OSD giving a warning and the reason.

[skorokithakis]

you won't be able to know what mode it engages and that's even worse

For me, "last mode" means "whatever the switch position before WP is", so it's not intuitive.

you at least know what mode you're in

For the use case I'm talking about, I'm expecting the mission to start working and might not even realize I'm in another mode.

if it fails engaging a navigation mode the aircraft should beep angrily

Unfortunately, with most non-stabilized modes, by the time I realize the aircraft is not flying itself, it's too late to recover, like what happened to me last time :/

[shellixyz]

Non-stabilized modes ? There is only one non-stabilized mode that's manual mode (plane only).

What happened to you ?