how to enable cameras in multi-uav simulation

[mzwtju]

My PX4 firmware version is v1.9.2

I followed the instruction in https://github.com/PX4/sitl_gazebo/issues/228 I changed directly the sdf argument. <arg name="sdf" default="$(find mavlink_sitl_gazebo)/models/iris_fpv_cam/iris_fpv_cam.sdf"/> in the mavros_posix_sitl.launch file and it workd well

Now I'm trying to enable camera in every drones I launch in the Gazebo when I'm using multi_uav_mavros_sitl.launch file.

I tried many ways like adding the sdf arg in the single_vehicle_spawn.launchfile but it did not work out.

I'm wondering how to do this?

thanks in advance!

[Jaeyoung-Lim]

@mzwtju which arg were you changing?

[mzwtju]

@mzwtju which arg were you changing?

actually adding a sdf arg

in https://github.com/PX4/sitl_gazebo/issues/228

So you need to keep the name argument as iris, and change directly the sdf argument. arg name="sdf" value="$(find mavlink_sitl_gazebo)/models/$(arg my_model_name)/$(arg my_model_name).sdf"/

I'm using multi_uav_mavros_sitl.launch file to launch multi-uav

So I take this https://github.com/PX4/sitl_gazebo/issues/228 as an example and change single_vehicle_spawn.launch file by adding a sdf arg

[Jaeyoung-Lim]

@mzwtju It should work that way. How were you changing them? Do you have a different sdf file for each vehicle?

[mzwtju]

@Jaeyoung-Lim Sorry for my late reply

This is how I do it:

1. I copy the iris_fpv_cam fie in the Tools/sitl_gazebo/models and create a new file named iris_fpv_cam2
2. changed theiris_fpv_cam2.sdf file and model.config file as well <model name='iris_fpv_cam2'>

   <include>
     <uri>model://fpv_cam2</uri>
     <pose>0 0 0 0 0 0</pose>
   </include>

   

3. In the multi_uav_mavros_sitl.launchfile I added <arg name="sdf" value="$(find mavlink_sitl_gazebo)/models/iris_fpv_cam2/iris_fpv_cam2.sdf"/> and <arg name="sdf" value="$(find mavlink_sitl_gazebo)/models/iris_fpv_cam/iris_fpv_cam.sdf"/> to the 2 drones I want to launch
4. in the single_vehicle_spawn.launch file added <arg name="sdf" default="$(find mavlink_sitl_gazebo)/models/$(arg vehicle)/$(arg vehicle).sdf"/>

It did not work that way. Do you know what part I'm missing?

[Jaeyoung-Lim]

@mzwtju You need to modify each model to use different mavlink ports as well as the fpv cam to use different udp ports.

Alternatively, have you checked the instructions in http://dev.px4.io/master/en/simulation/multi-vehicle-simulation.html#no_ros ? Currently this is automated by xacro macros with a bashscript without ros. You would just need to add cameras to the xacro scripts

[mzwtju]

@Jaeyoung-Lim
Thanks for your help. I didn't found udp ports in my fpv_cam.file .

I insert udp part and modify different ports.

          <plugin name="GstCameraPlugin" filename="libgazebo_gst_camera_plugin.so">
            <robotNamespace></robotNamespace>
            <udpPort>5600</udpPort>
          </plugin>

Still can't work it out. Do you have any example? I'm a newbie in this.

[Jaeyoung-Lim]

@mzwtju I already sent you the example where you can do it "without" ROS. If you want to indeed use ros, you need to figure out what is wrong e.g. launching different models separately to see if it works

[mzwtju]

@Jaeyoung-Lim I want to use ROS to do this. Appreciate your help! I would figure out what I'm missing

[Jaeyoung-Lim]

@mzwtju Did you figure it out?

[mzwtju]

@Jaeyoung-Lim Nope.

I think I could use newer version after v1.10.x because there is a new single_vehicle_spawn_sdf.launch file Here's a example https://gitee.com/robin_shaun/XTDrone/blob/master/coordination/launch/multi_vehicle.launch#L152

Is this https://github.com/PX4/Firmware/issues/14323 fixed? When I update submodule, same error occur :

fatal: reference is not a tree: 8569aec5bb709acb2fec7ccb5a5a4405f0cdec2a
Unable to checkout '8569aec5bb709acb2fec7ccb5a5a4405f0cdec2a' in submodule path 'Tools/sitl_gazebo'

Tried run git submodule sync or make submodulesclean. It won't work.

[Jaeyoung-Lim]

@mzwtju Yes, it is fixed. I don't quite understand. Were you trying to use multivehicle sim with XTDrone? I have never looked at the project, so I am not sure how it works

[mzwtju]

@Jaeyoung-Lim Yes. I want to use XTDrone multivehicle sim. It seems by using xmlstarlet tools to change UDP ports in SDF file. I am not sure either.

[mzwtju]

@Jaeyoung-Lim How to fix PX4/Firmware#14323 btw.XD

[Jaeyoung-Lim]

@mzwtju It is fixed as I already stated in the comment above

[mzwtju]

@Jaeyoung-Lim OK. Thank you.

[adbidwai]

@mzwtju Were you able to run many drones with camera feeds in your multi UAV simulation using ROS and Gazebo?

[mzwtju]

Yes. But I don't remember the specific steps to run that simulation. I remember I took the XTDrone project for example. https://gitee.com/robin_shaun/XTDrone#/robin_shaun/XTDrone/blob/master/README.md https://www.yuque.com/xtdrone/manual_en @adbidwai