PX4/QGC Flight Modes

#1

I don’t understand all flight modes in qgc,

I read the description on http://px4.io/docs/flight-mode-selection/ but still don’t understand all of them.

What FM do need gps lock?

Due to my Mission Planner background I’m used to these FM, (Stabilized, AltHold, Auto, RTL, Land, Sport, Drift, Acro, PosHold and Loiter).

My Questions:

  • “APM Loiter” is “PX4 AUTO / PAUSE”, right? it needs GPS Lock
  • What is Rattitude, Manual and how dose it differ to Acro? I may need to fly it to be able to understand it. All three do not need GPS Lock.
  • Is “PX4 ALTITUDE CONTROL” the same as “APM AltHold”? It dosn’t need a GPS Lock, right?
  • “PX4 POSITION CONTROL” is the same as “PX4 ALTITUDE CONTROL” but now with GPS Lock as a safety, right? Like “APM PosHold Mode”
  • Dose LAND need a GPS Lock?
  • Offboard is to fly without RC, right?
  • “PX4 AUTO / TAKEOFF”, does it work the same as in APM?

At the APM Wiki all flight modes are very well explained. http://copter.ardupilot.com/wiki/flight-modes/ even with Video and the Parameters where you can tune it. Would be nice to have something similar here.

Can anyone help me understand the flight modes a bit better?
Thanks very much

Pixraxer as a RACER
#2

Hi Sn0west, did you ever find a good explanation of the Flight Modes in QGC?

#3

Not really unfortunately. Do you have any specific questions?

#4

I don’t understand all flight modes

#5

A short summary about the Flight Modes I use on my PX4 for a Multicopter:

  • Stabilized : This is mostly like Manual in NAZA. The FC will stabilize the UAV to be horizontal. Wind and a not perfect Throttle to hover will cause drift in horizontal and vertical ways. Used mostly for takeoff and landing.
  • Rattitiude : Is mostly like Stabilized except, that close to the min/max Endpoints the Stick commands will no longer be considered as the Flight Angle but a angular change. This will cause a Flip when the Stick is in extreme positions.
  • AltHold : Same as Stabilized except that Height is maintained by using the Alt from the Estimator (which may include Baro, GPS, Lidar, US Devices etc). Same as ATTI in NAZA.
  • PosCtrl : This is is fully GPS Controlled Position Control. Sticks in Center the UAV will maintain its position. Roll & Pitch will translate to the position change in the respective direction.
  • Return to Launch (RTL) : The UAV will return to the position that was recorded at Arming (if set so in the params) and land at this position. Depending on the settings it may disarm after landing.
  • Mission : The UAV will start / continue the Mission that was uploaded from a Ground Station.
  • Loiter / Pause : The UAV will Pause a Mission and Loiter at this position.

AFAIK : RTL, PosCtrl, Mission, Loiter/PAUSE will require GPS Lock. Arming when a GeoFence is set requires GPS Lock as well in order to arm.

#6

Is there a similar list for planes? Looking in QGC, I have questions: Is “Hold” the same as a traditional loiter? Or is that “Position”?

And what does “Acro” do differently from “Manual” or “Rattitude”?