VTOL precision landing (Lidar or RTK GPS?)

ArduPlane VTOL Plane
1

Hello to the community!

We are designing a classic 4+1 (pusher) fixed wing VTOL with a mass of 6.5kg. FC is the Cube Orange.

I would like to ask which method is more accurate for a precision vertical landing of the vehicle?

Is it to use an RTK GPS system or a downwards looking lidar sensor?

The only phase of the flight envelope that concern us is the critical touchdown phase.
Which parameters are involved when using a lidar for the touchdown? Are there any directions on how to achieve this functionality?

Is the Benewake - TFmini Plus LiDAR - IP6- 12m range suitable for this purpose or you can suggest something more suitable as a sensor?

Thank you for your time!

2

RTK provides 3D positioning. LiDAR provides altitude only.
There are three cases

  1. Avoiding hard landing - terrain altitude sensor (for example downward facing lidar) is enough.
  2. precise RTL - RTK with quick survey in is enough (RTK base station offset doesn’t matter)
  3. precise landing on known coordinates - RTK with precisely known location or RTN (network based RTK service) is required

The 12m range should be ok for not crash landing, though according to documentation it can decrease to 5m for dark targets.

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3

What is your goal for precision landing? You can use both RTK and Lidar.

If it’s just the nicest touch down, then my vote is for lidar. It will tell the drone exactly how high it is above the ground, no external data required. This is common on many commercial VTOL.

If you need to be over an exact point, then RTK will get you there. But height over the ground is still based on external data, or the recorded home point if you’re going back to the same place.

But you can use both systems together because they are impacting different portions of the flight control.

4

thank you LupusTheCanine,
thank you Allister Schreiber,

our scope is just the nicest touchdown. We don’t care if we land one or two meters off target.

Could you indicate the variables i need to set up for this scenario using the benewake 12m lidar?

Thanks!

5

Regular lidar configuration as described on the appropriate wiki page and Understanding Altitude in ArduPilot — Plane documentation

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