Gazebo and SITL Map/World Synchronization

Lucas_Baptista · August 17, 2021, 11:34pm

Hello!

I’ve generated a .tif file of my college and created a world file on gazebo. My goal is to do simple missions with the Software In the Loop and/or Mission Planner, but I’m stuck in a problem that I couldn’t really find a solution.

To illustrate the problem, I’ve positioned the ArduCopter in a location in the Gazebo World that is basically the same one that the Software In The Loop is initializing, just like in the next two pictures:

But when I try to send the drone to a direction, like the drawn in the SITL picture, the drone in Gazebo moves towards a different direction. There is something that I can do to handle with it?

stephendade · August 18, 2021, 1:14am

Gazebo uses a different XYZ ordering to ArduPilot. I believe you need to rotate the maps/terrian 270 degrees (in yaw) to have it line up with Aurdpilot.

Lucas_Baptista · August 19, 2021, 2:02am

I’ve tried to rotate the terrain itself, as you said, with the pose command in my SDF file, but looks like it doesn’t work with heightmaps…

stephendade · August 19, 2021, 2:15am

Correct. Known issue with Gazebo.

You’ll need to find a software package to rotate it for you.

EDIT:
Here’s a script I made to rotate heightmaps (in tif format):

gist.github.com

https://gist.github.com/stephendade/75583a3138c4deb9e4b26b3380681eed

rotate.py

#!/usr/bin/env python3

# Rotate a DTED into Gazebo format (270deg rotate)
# So it matches the Gazebo axis format
# Requires GDAL to be installed

from osgeo import gdal, osr
import numpy as np
import argparse, os

This file has been truncated. show original

Lucas_Baptista · August 19, 2021, 10:59pm

Thank you so much, @stephendade!

I was trying to use your script and I’m getting this error:

Traceback (most recent call last):
File “./rotate.py”, line 42, in
dst_ds.GetRasterBand(1).WriteArray( array_rot270 )
File “/usr/lib/python3/dist-packages/osgeo/gdal.py”, line 2547, in WriteArray
callback_data = callback_data )
File “/usr/lib/python3/dist-packages/osgeo/gdal_array.py”, line 381, in BandWriteArray
raise ValueError(“array larger than output file, or offset off edge”)
ValueError: array larger than output file, or offset off edge

Does anything like that have ever happened to you?

stephendade · August 19, 2021, 11:49pm

I think the input heightmap needs to be an exact square (same number of rows and columns). It’s been a while since I’ve used the script.

LukasBrno · June 24, 2023, 8:20pm

Hi @Lucas_Baptista , did solve the issue? I have similar issue, when I want to use my own world. I have noticed there is some setup of orientation system in ardupilot plugin in sdf file. Can I fix it with that?
Lukas