Sim-to-Real Pipeline for Quadrotor Trajectory Tracking

Simulation environment for testing trajectory tracking controllers on a Crazyflie 2.1 nano-quadrotor using ROS2 Humble and Gazebo Classic 11.

Platform

Software	Version
Ubuntu	22.04 LTS
ROS2	Humble Hawksbill
Gazebo Classic	11.x
Python	3.10.x

Quick Start (Fresh System)

Prerequisites

• Ubuntu 22.04 with ROS2 Humble installed
• Git configured with your name and email

1. Clone this repository

git clone https://github.com/YOUR_USERNAME/crazyflie_trajectory_ws.git ~/crazyflie_control_ws
cd ~/crazyflie_control_ws

2. Run the setup script (one time only)

chmod +x scripts/setup_dependencies.sh
./scripts/setup_dependencies.sh

This script:

• Installs all apt and Python dependencies
• Creates the Python virtual environment
• Clones crazyswarm2 and motion_capture_tracking
• Builds the complete workspace

3. Activate workspace (every new terminal)

source ~/crazyflie_control_ws/scripts/activate_crazyflie_ws.sh

4. Run the simulation

Terminal 1:

source ~/crazyflie_control_ws/scripts/activate_crazyflie_ws.sh
ros2 launch cf_trajectory_controller cf1_full_simulation.launch.py

Terminal 2 (after 10 seconds):

source ~/crazyflie_control_ws/scripts/activate_crazyflie_ws.sh
ros2 run cf_trajectory_controller cf_trajectory_plotter

Switch Controller or Trajectory

Edit one line in the config file:

nano src/cf_trajectory_controller/config/controller_params.yaml

active_controller: "cascaded_pid"   # cascaded_pid | conventional_smc | ...
active_trajectory: "figure8"        # figure8 | circle | helix | hover

Repository Structure

crazyflie_control_ws/ ├── src/ │ ├── crazyflie_gazebo_sim/ # Gazebo world, SDF model, C++ plugin │ └── cf_trajectory_controller/ # Controllers, trajectories, ROS2 nodes ├── scripts/ │ ├── activate_crazyflie_ws.sh # Source this every session │ └── setup_dependencies.sh # Run once on fresh system ├── docs/ │ ├── crazyflie_sim_guide.md # Complete replication guide │ └── architecture_doc.md # Software architecture reference └── logs/ # Plots and metrics (gitignored)

Controllers Implemented

Controller	Status	RMS 3D Error
Cascaded PID	✅ Working	0.055 m
Conventional SMC	🔄 In progress	—
Super Twisting SMC	🔄 Planned	—
NS Terminal SMC	🔄 Planned	—

Documentation

• Complete Replication Guide
• Architecture Reference

References

• IMRCLab/crazyswarm2
• Silano et al., CrazyS: A Software-in-the-Loop Simulation Platform for the Crazyflie 2.0, ROBOT 2017 (arXiv:1811.03557)