Multiple Drone Connection in QGroundControl are not connecting at a time

EW_RND02 · May 14, 2025, 7:58am

hello there, so I am simulating 3 drones in gazebo and I want then to be controlled from QGC where each drone gets its own plane and they be monitored on the map.
I am doing in in sitl. I have launched the gazebo runway.launch. the drones are there, i have defined separate sdf files, parameter files and of course the separate SYSID_THISMAV for each drone:
SYSID_THISMAV 1 for drone 1
SYSID_THISMAV 2 for drone 2
SYSID_THISMAV 3 for drone 3.
and then i launched the drones in tcp connections, connected via:
sim_vehicle.py -v ArduCopter -f gazebo-drone1 --console -I0 --out=tcpin:0.0.0.0:8100
sim_vehicle.py -v ArduCopter -f gazebo-drone2 --console -I1 --out=tcpin:0.0.0.0:8200 sim_vehicle.py -v ArduCopter -f gazebo-drone3 --console -I2 --out=tcpin:0.0.0.0:8300.

i have also defined Comm links in QGC to connect all these three vehicles to QGC but only one connects after i hit the connect button and after pressing all the connect buttons, the drones appears flickering on the map and i cannot chose drone1/drone2/drone3 from the dropdown menu as shown in the below image:

i have followed this GitHub repository step by step but at the end the QGC problem pops us:

github.com/Intelligent-Quads/iq_tutorials

docs/swarming_ardupilot.md

938197fda

# Swarming Using Ardupilot

## Video Tutorial at https://youtu.be/r15Tc6e2K7Y

This tutorial shows you how to model and control a swarming using ardupilot and Gazebo

## Pre-rec

add the models folder in the iq_sim repo to the gazebo models path
```
echo "export GAZEBO_MODEL_PATH=${GAZEBO_MODEL_PATH}:$HOME/catkin_ws/src/iq_sim/models" >> ~/.bashrc
```


## Connecting Multiple Vehicles SITL to Gazebo

You should think about ardupilot as purely a control system. It takes sensor inputs and outputs commands to actuators. Gazebo is playing the role of a Flight Dynamics Model (FDM). The FDM encompasses all of the following, sensor models, actuator models and the dynamics of the vehicle. In real life ardupilot would communicate with your sensors via serial connections, but when you run SITL with gazebo ardupilot talks to the sensors and actuators via UDP connections (an IP protocol). Because of this we will need to specify different UDP ports in our robot models such that these streams do not conflict. 

Lets start by copying the drone1 folder in `iq_sim/models` and paste it as a copy. rename the folder to drone2.

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EW_RND02 · May 27, 2025, 3:34am

the issue is solved as i used udp connection instead of tcp and adding the sysid in terminal with the indivisual drones connection. and the rest is the same as mentioned above.

sim_vehicle.py -v ArduCopter -f gazebo-drone1 --console --map -I0 --out=udp:127.0.0.1:14550 --sysid 1

EW_RND02 · May 27, 2025, 3:35am

and offcourse edit the comm link of drone1…drone6 in QGC

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Multiple Drone Connection in QGroundControl are not connecting at a time

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