Cruise or loiter without throttle possible, like in Inav?

Hi guys,

when flying a fixed wing how is it possible in auto modes such as cruise or loiter, to glide without throttle?

This is a great feature in Inav - and although I prefer Ardupilot in many ways - it would be great to loiter or cruise sometimes, without throttle input.

Or is there another mode to hold direction without throttle? Or loiter around a fixed GPS point?

I realise this will probably only work in conditions with very little or no wind.

Thank you in advance for your help! :slight_smile:

Soaring — Plane documentation (ardupilot.org)

Thank you! Do you have experience with it and does it work well?

Ardupilot has been supported for a long time, as long as you use the airspeed sensor, if the speed exceeds the specified speed the motor will automatically stop and float until the speed decreases and the motor will be active again.

but!! don’t ever use (entrust) that airspeed with synthetic airspeed, my plane almost got crash with it

just skip to @03:08 when the stall happened

yes…I’ve never had a problem “IF” using the real airspeed sensor

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Which airspeed sensor do you use? There are many suggested on arduplane, does expensive mean good?

Actually I only want to glide in Loiter or Cruise without throttle, I guess I can do that via the “Select 88:Soaring Enable” option on any RC-channel?

My next step then will definitely be to try the actual soaring mode, sounds great! :slight_smile:

Unfortunately, yes, digital is more expensive than analog, it doesn’t mean that analog is not good, it’s just that digital is more precise
installing the airspeed must be right, sometimes we have to direct the pitot a little to get more precise numbers (requires trial and error in several flights)

“whatever you will use when it comes to automatic throttle management, you must have an airspeed sensor available”

using soaring is not what you want, the soaring function is to find a thermal source to float longer, not for cruise or loiter (yes it will be loiter but the location that fc decides is not up to you) :slight_smile:

but wait for the experts to response, just ignore this comment because it might be wrong :slight_smile:

Thank you korakora and Lano!

As I only want to achieve a “Heading Hold” or “Loiter” WITHOUT THROTTLE input, maybe the soaring feature is too sophisticated :slight_smile: :thinking:

Does anyone know if or how it is possible to do that? Just like “2D CRUISE” / "Heading Hold"in iNav?
See wiki:
Modes · iNavFlight/inav Wiki · GitHub

“HEADING HOLD”

This flight mode affects only yaw axis and can be enabled together with any other flight mode. It helps to maintain current heading without pilots input and can be used with and without magnetometer support. When yaw stick is neutral position, Heading Hold mode tries to keep heading (azimuth if compass sensor is available) at a defined direction. When pilot moves yaw stick, Heading Hold is temporary disabled and is waiting for a new setpoint.

Maybe this other comment from the iNav wiki helps:
Navigation modes · iNavFlight/inav Wiki · GitHub
Prior to version 2.6 on a fixed wing the motor will stop in all Nav modes except Nav RTH and Nav WP if the throttle is reduced below the Min_Check setting. From version 2.6 this behaviour is controlled using the nav_overrides_motor_stop setting which by default keeps the motor running in all Nav modes.

Thank you Gents!

Normally Ardupilot will try to use the motor to keep the desired altitude and heading. If you want it to be able to glide, then I think soaring is the proper mode to use. It’ll turn off the motor and glide as long as the aircraft is above SOAR_ALT_MIN altitude.

If you don’t want it on all the time you could put it on a switch to enable it when desired. You can also decide whether to allow it to automatically follow thermals or not.

Hi cbf, thank you very much for the tip, I’ll try that! :+1:

Hi cbf123!
I followed your tip and it is working great! Just put it on a switch, then in “Config” and “full parameter list” find a free channel and put that on “88: Soaring Enable” - ready!

Now I need to play around with the settings, as it “pumps” quite a bit when in the soaring mode. CG is of course correct and it also flies beautifully in Manual or Auto modes. Could it be these factors, to do with drag?

|SOAR_POLAR_B|0,031||0.005 0.05|Induced drag coeffient|
|SOAR_POLAR_CD0|0,027||0.005 0.5|Zero lift drag coefficient|
|SOAR_POLAR_K|25,6|m.m/s/s|20 400|Cl factor 2mg/(rho*S)|

or maybe the airspeed, I don’t have an airspeed sensor (yet)?:

SOAR_CRSE_ARSPD 0 5 50 If non-zero this airspeed will be used when cruising. If set to -1, airspeed will be selected based on F33.
SOAR_THML_ARSPD 0 5 50 If non-zero this airspeed will be used when thermalling.

Thank you!

I’m afraid I can’t help you there…I’m far from an expert in this stuff, I’m just good at reading documentation. :slight_smile:

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