This project is based on the Gazebo Simulation for Crazyflie CRTP sim_cf from https://github.com/wuwushrek/sim_cf
It features
In contrast to the original sim_cf, hardware-in-the-loop (HITL) is not supported.
Beside this ROS2 package you will need
Tested on an Ubuntu 22.04 LTS machine
Basic dependencies
sudo apt-get install cmake build-essential genromfs ninja-build
Protobuf, eigen3 and google-glog dependencies
sudo apt-get install protobuf-compiler libgoogle-glog-dev libeigen3-dev libxml2-utils
Cyclone DDS
sudo apt install ros-humble-rmw-cyclonedds-cpp
Xacro library
sudo apt install ros-humble-xacro
Clone ROS2 version of mav_comm into your colcon overlay (assuming ~/dev_ws)
cd ~/dev_ws/src
git clone https://github.com/CrazyflieTHI/mav_comm.git
Move into your colcon overlay (assuming ~/dev_ws) and use colcon build
cd ~/dev_ws
colcon build
Running the simulation requires
The number of simulated Crazyflies is determined by the main launch file main.launch.xml in the sim_cf2/launch folder. By default, two Crazyflies are simulated and code for the instantiation of four further Crazyflies is present but commented out. Adjust the launch file to your needs by adding or removing Crazyflies. Initial pose and rotor color is set in the main.launch.xml file.
Open a terminal and source the ROS2 workspace if not done already (assuming the overlay or workspace in ~/dev_ws)
source ~/dev_ws/install/local_setup.bash
Use the ROS2 launch command to start the sim_cf2 simulation
ros2 launch sim_cf2 main.launch.xml
Gazebo will start in paused mode and will try to establish a connection to the software-in-the-loop Crazyflie firmware instances.
Open a new terminal and move to the scripts/sim_cf2 folder in the Crazyflie firmware repository (assuming ~/repos/crazyflie-firmware)
cd ~/repos/crazyflie-firmware/scripts/sim_cf2
Run the run_cfs.sh script with as many instances of simulated Crazyflies as needed by providing the amount of Crazyflies as argument (e.g. two)
./run_cfs.sh 2
The SITL instances will establish a connection to Gazebo
Press PLAY in Gazebo
Start your cflib-based python script with activated simlink driver. Example scripts can be found in the Crazyflie python library https://github.com/CrazyflieTHI/crazyflie-lib-python/tree/master/examples/sim_cf2
Run for example the autonomousSequence.py script
python autonomousSequence.py
Press Ctrl+C in the terminals running Gazebo and the SITL instances
Processes should get killed and POSIX message queues should get deleted. If POSIX message queues are not deleted due to errors, they eventually may cause issues when starting the simulation again. The queues are located in /dev/mqueue
If problems occur, delete the queues manually
Show queues
ls /dev/mqueue
Delete the queues
sudo rm /dev/mqueue/<sim_cf2_queues>
An experimental Multi-ranger deck can be used in the simulation. It consists of four Hokuyo range sensors mounted on a rigid platform attached on top of the Crazyflie.
To use the Multi-ranger deck, enable it in the main.launch.xml file for every Crazyflie individually.
<arg name="enable_mr_deck_1" default="true" />
<arg name="mr_deck_visualize_1" default="true" />
By setting mr_deck_visualize_
to true
the laser ray will be visualized.
With the simulated Multi-ranger deck, Bitcraze's wall following example can be run. Load a world that contains walls, such as lab_aux.world, by specifying the world name in start_gazebo_world.launch.py
def generate_launch_description():
world_file_name = 'lab_aux.world' # Select world from worlds folder
package_name = "sim_cf2"
...
A slightly modified version of the wall following example script is located in https://github.com/CrazyflieTHI/crazyflie-lib-python/tree/master/examples/sim_cf2
Start the Gazebo Simulation, an instance of the firmware SITL and run the example.