Land on april tag with Starling 1 gps denied using VIO

[nick anthony]

Hi, we are a group of 5th year engineers working on our capstone project. We need the starling drone to be manually controlled before the operator presses a button which initiates automatic landing at the april tag. We have followed all documentation we could find for april tag re-localization, we have a fixed tag which does relocalize the drone's fixed frame.

On your documentation you have a video of a m500 px4 drone landing on an april tag but with no following documentation on how this was achieved. We have set our april tag in the configs to be at fixed (0,0,0) and tried sending a mav_cmd_nav_land_local which didn't work probably because of fixed vs local frame.

We started looking at offboard modes on the drone. We tested figure 8, wps and noticed that these decided to send the drone straight into the wall. We tried to set offboard mode to off so that we could send the SET_POSITION_TARGET_LOCAL_NED however we noticed in offboard mode off no commands were going through. We are coding on the mavlink layer which is a layer below MAVSDK/MAVROS.

We have also looked at the voxl-sdk repo and saw that 4 years ago there was offboard code to land on tag however that code never seemed to be completed. Right now we are trying to code our own offboard mode on the drone through voxl-sdk voxl-vision-hub to convert fixed frame (0,0, -1) to local frame before sending SET_POSITION_TARGET_LOCAL_NED.

If there is any knowledge you can pass us that would be much appreciated we have been stuck on trying to land on an april tag for a while.

Thanks,
Nick