PX4Flow without Lidar for non-GPS navigation

Hello all!

I would like to use PX4FLOW for non-GPS environment with my flying wing. Could you please help me if it is necessary to use Lidar in combination with it or not? It looks like it will not give me good values at heights more than 40 meters so optical flow will not use it correctly for position estimation. Operating height will be more than 500 meters…

Thank you in advance for any helpful tip!

Maybe there is an option for PX4FLOW to use barometer values instead of rangefinder for scaling?

Is px4flow supported on planes?

I suppose yes if take into account the info from this page Optical Flow Sensors (landingpage) — Plane documentation and the fact that Arduplane firmware has all necessary parameters to enable and tune PX4FLOW. The warning that “The PX4FLOW is not yet supported in Plane or Rover” looks like obsolete.

Please correct me if I’m wrong.

I know there was talk abour using it for the landing phase of a vtol plane but i have never seen it discussed for use on a regular plane during normal flight.

As written in the plane wiki page:
These are camera modules that use ground texture and visible features to determine aircraft ground velocity.

OpticalFlow is a velocity estimator , not a position estimator, so you can use it at low velocity and low altitude to assist the EKF on estimating the x-y velocity.

You cannot use it as GPS denied navigation as it will not supply positionning information.

Accordingly to this page GPS / Non-GPS Transitions — Plane documentation (see section with Lua scripts) it is possible to use optical flow for in-flight transitions between GPS and Non-GPS environments. So it can be assumed that with auxiliary data from optical flow accuracy of EKF estimator can be increased. We don’t speak about perfectbut about more precise positioning in case of GPS jamming.The main question here is if it make sense at high flight altitudes or not. Any more ideas or experience?

Hum… I doubt that has been implemented into Plane , might be an error during wiki indexation

Optical flow for velocity sensing requires both the optical flow sensor and a rangefinder distance. In a copter it’s easier, for hover it just has to adjust things so the optical flow sensor “picture” doesn’t change.

I opened a PR on Plane WIKI asking to add some “nuance” to the use case on Planes

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Thank you very much! It will be nice to make this topic clear for all and maybe develop optical flow usage for planes.