Poshold outdated docs?

the docs for poshold (PosHold Mode — Copter documentation) state: " The PosHold flight mode is similar to Loiter in that the vehicle maintains a constant location, heading, and altitude but is generally more popular because the pilot stick inputs directly control the vehicle’s lean angle providing a more “natural” feel."

Does Loiter pitch stick not map directly to angle like in poshold?

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Hello lordvon,

According to Loiter Flight mode page, Roll and Pitch sticks control rate of movement in the XY plan instead of lean angles and as soon as you release the stick the drone will attempt to stop.

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@dkemxr i think you mentioned that loiter basically supersedes poshold but i want lean angle control and it seems like loiter would be the wrong choice for me

I don’t think it supersedes… it just try to satisfy other user’s needs. In general people from fixed wing when start to fly copters like the poshold mode because it is more natural for them on thinking about lean angles. But people who already begins with multi-rotors are more comfortable in general with loiter flight mode.

Yes, essentially it does. They both use the AltHold Controller, they both have position control, same control. But, Loiter has many more configurable parameters, PosHold has 2. Easy enough to try both. I haven’t had PosHold as an available mode for some years.

one thing that I prefer is that pitch stick is directly mapped to angle. is that configurable for loiter?

It’s the same to LOIT_ANG_MAX. Try it.

Am I right that the following statements are true?

  • PosHold is basically AltHold with an additional feature to hold the position when roll/pitch sticks are centered;
  • in Loiter, the user controls the velocity vector instead of attitude. More precisely, the aircraft has an idea of the intended position, which may change as the user plays with the roll and pitch sticks, and tries to remain at that position;
  • @lordvon asks about the differences listed above;
  • @dkemxr answers a different question;
  • everyone is confused.

:laughing:

That is a clear and accurate summary as far as I can tell, except I think that @dkemxr meant that you can get a precise angle through LOIT_ANG_MAX (which is max requested angle by pilot or autopilot). so for example if you want to be able to command autopilot to 20 deg then set it to LOIT_ANG_MAX and go full pitch stick.

Use search for “new loiter” and you will find a Blog thread with Dev discussion. It was “new” in 2017 but the discussion is good and more comprehensive than the Wiki entries.

Yes poshold description is accurate. Loiter is good but I will add some additional notes. As you said loiter is horizontal velocity command which means your pitch/roll stick position translates directly to a speed over the ground based on the LOIT_VEL_MAX (I think that’s the name). When you center the pitch/roll stick. A trajectory is planned to a stopping point after which position is held. The LOIT_ANG_MAX provides the user a way to limit the max angle the controller can command to achieve acceleration or velocity if the lean angle to maintain a velocity is higher than the LOIT_ANG_MAX value.

To answer this question directly, no, loiter cannot be configured so that pitch stick is directly mapped to angle.

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