"Wing Level Hold".

[laasmooi]

Hi all Inavers,
I often use "Altitude Hold" but it should be nice to also have "Wing Level Hold". The idea is to climb quick and easy to a certain altitude while the wing stays level with the horizon but still is manually overridable.
Any ideas?

[Jetrell]

Do you mean a Constant Climb Angle function ?
So you can pull back on the elevator stick to set a certain climb angle, then release the stick. And the fixed wing will continue to climb at that angle. e.g. if you're flying up a long mountainous incline.

[MrD-RC]

Just use course hold mode, and add up elevators with a slider or pot.

BTW, althold is not something that’s needed on fixed wing anymore. At this point in time, it should only be used with Angle mode.

[laasmooi]

Ah, that makes sense! Thanks.
It means when the plane/FC is in course mode, I still have throttle and elevator control? And I can manually override the course?

[MrD-RC]

Yes. Course hold has manual throttle and you can change course.

[laasmooi]

That is all I need to know. Thanks!

…

On Thu, Aug 31, 2023 at 7:07 PM Darren Lines ***@***.***> wrote: Yes. Course hold has manual throttle and you can change course. — Reply to this email directly, view it on GitHub <#9269 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABMEPNMQOOC4MFRBGOXJ4NLXYB5ARANCNFSM6AAAAAA4FMCCEQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[breadoven]

Well theoretically you could just use ACRO to do this. It should hold whatever attitude you've set the plane to for the climb, roll level, pitched to the desired climb angle. Unfortunately it tends to drift after a while so would need correcting every now and again to keep it on course.

[Jetrell]

Yes it would appear that Flight_Axis_Angle_Override is just ANGLE mode, in which the user can change what angle is LEVEL to the ground at center stick. Rather than it being an Attitude controller.

After reading your post, and what is actually required.. Having a selection switch etc, to engage and escape from the set attitude, with safety.. I think an extension of ANGLE mode itself, is likely to confuse users. Especially if they have to bail in a hurry to prevent a crash.
I really think it would be better to have it as LEVEL mode, or something like that, built upon a navigation controlled mode, like Cruise or Althold for fixedwings... So auto throttle could assist maintaining large radius turns or slow gradual climbs.

This way the user can hold the stick (roll or pitch) at the desired attitude for a second or so. Then it would hold that attitude.
And once the stick was released back to center. If it was moved a second time (outside a small deadband) it would disengage back to what the default of the mode it was built upon.. i.e holding altitude or level to the ground stabilization.
I don't think it would require more than 30degrees of pitch or roll. Considerably less than is required for good rate control over ANGLE mode.. Anymore would produce gradual side slip. Or push the wing past stall for a prolonged period of time in a climb, wasting energy.

I personally never used Angle or Horizon on a fixed wing for self levelling because Altitude Hold does the same thing anyway (which uses auto enabled Angle).

Me neither.. Its either Acro or Cruise/ Course hold... But. there are a great many users that do use ANGLE mode.. Which is what I believe Darren was referring when he said it may be better to have it as a seperate mode.

[MrD-RC]

Oh, 100% I think it should be a new mode. Pilots are used to what is available already. This would just be like a more locked Acro, from a pilots perspective. From a code perspective, it may be basically angle with a variable level (the current level when the stick is centred). But from the pilot perspective, it’s closer to Acro, as there’s no self levelling and no rotational limits.

So Attitude Hold as a mode would make most sense to me. I think that adding it to Angle with specific stick inputs would just be confusing. It could lead to panic crashes. I also don’t think the existing modes should be changed or renamed.

[breadoven]

You're right, a new mode is the best way. Just seems there are too many modes and not enough channels to control them although in this case I guess it would only be active when most other modes weren't, a bit like ACRO, so maybe it's not so difficult to configure things using an existing channel.

[Jetrell]

Maybe it could even be a flight mode modifier like Heading hold. That could be enabled with modes like Acro, Altitude hold, Course hold or Cruise, according to the users flight requirements ?

[MrD-RC]

Channels aren’t really a problem. All my 8 flight modes are on channel 6. It’s not a problem with OpenTX, EdgeTX, or ETHOS.

[laasmooi]

I'm just an ordinary user but I'm heavily impressed by your knowledge.
A good reason to study a bit more and hopefully understand this matter.
A big thanks anyway!

[sensei-hacker]

Well theoretically you could just use ACRO to do this. ... Unfortunately it tends to drift

Yep, this is just the definition of acro. Would just need get rid of the unintentional drift at center stick.

@MrD-RC

This would just be like a more locked Acro, from a pilots perspective

Yeah just acro without the unwanted drift, right.

Oh, 100% I think it should be a new mode

Would you think a new mode should be used if we can instead just make acro behave as already defined - don't drift when at center stick?

I proposed a simple change to get rid of the drift, so center stick maintains attitude just as it's supposed to.

I think the answer is clear, but just to double check that you would agree. Should we have these two modes?:
Acro with uncommanded drift
Acro without unwanted drift

I would think that if we can get rid of the unwanted drift at center stick, there's no need for an extra mode. Would you agree?

@breadoven made a proposal which in turn gave me an idea on how to completely eliminate drift in rate mode, so it maintains attitude consistently when the stick is centered. In a simple way too.

[MrD-RC]

I don’t believe acro is supposed to be attitude lock. It’s just supposed to stabilise wind buffeting. Effectively manual with stability.

[sensei-hacker]

Maybe I'm misunderstanding. What is acro supposed the do when the sticks are centered?

[Jetrell]

ACRO applies a mild attitude stabilization, being based on a RATE controller, with the strenght of the i-term dictating how well it will attempt to hold attitude at center stick.
But in the case of Breadovens commit... Its different again... It uses the ANGLE rate controller, based on gravity vector level control offset. Which uses the AHRS via sensors to correct for attitude drift. To the best it can anyway, with some issues being noticed in my tests, beyond what the AHRS can compensate for at higher climb angles, when acceleration forces are close to 1G. (power train permitting)

[sensei-hacker]

The idea is to climb quick and easy to a certain altitude while the wing stays level with the horizon but still is manually overridable.

That sounds like Angle mode or cruise, using your pitch trim if you want to be be completely hands off, be able to set your radio down while it climbs.

That's how we do long climb outs in full-sized aircraft.

[MrD-RC]

Totally agree. For a consistent climb. The best mode to use would be course hold. Then add up elevator with a pot. Acro with attitude hold isn’t what I would think of for this at all. That’s way too ArduPilot thinking. Acro is for having fun.