🚁 MATLAB Quadcopter Dynamics Simulator

A minimalist quadcopter model and hover simulation built in MATLAB/Octave, based on Francesco Sabatino’s master thesis at KTH. This project demonstrates the basic 6-DOF rigid-body dynamics of a quadrotor in free flight, focusing on attitude and position evolution over time.

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📘 Reference

Francesco Sabatino, “A Unified Approach to Quadcopter Control”, KTH Master Thesis, 2015.
📄 Download PDF

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📁 Project Structure

Matlab-Quadcopter-Dynamics-Simulator/
├── LICENSE                        # MIT License
├── pictures/                      # Visual explanation
│   ├── control_input.jpg          # Force/torque illustration
│   ├── figure1.jpg                # Example position output
│   ├── figure2.jpg                # Example orientation output
│   └── quad_equation.jpg          # Dynamics equations
├── project/                       # MATLAB source code
│   ├── quadvar.m                  # System parameters and initial conditions
│   ├── quadmodel.m                # State update equations (Euler integration)
│   ├── quadrun.m                  # Main runner script (initialization + simulation)
│   └── quadplot.m                 # Plotting utility
└── README.md                      # Project documentation

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🧠 Overview of System Dynamics

📷 Quadcopter Equation of Motion

🧭 Control Input Diagram

The control input vector:

• u₁: total thrust
• u₂, u₃, u₄: roll, pitch, and yaw torques

These are derived from rotor speeds and used in the Newton–Euler equations to simulate translational and rotational motion.

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💻 Prerequisites

• MATLAB R2018a+ or GNU Octave v4.0+
• No additional toolboxes required
• Add /project folder to your MATLAB/Octave path

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▶️ How to Run

1. Clone or download the repo:

   git clone https://github.com/2black0/MATLAB-Quadcopter-Dynamics-Simulator.git

2. Open MATLAB or Octave and set the working directory to /project

3. Run the simulation:

   quadrun

4. The script simulates 30 seconds of hover flight and saves two output plots:

   • figure1.jpg: position in X, Y, Z axes
   • figure2.jpg: orientation angles (Roll, Pitch, Yaw)

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📊 Sample Outputs

Position (X, Y, Z)	Orientation (Roll, Pitch, Yaw)

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⚙️ Code Breakdown

quadvar.m

• Defines parameters: mass m, arm length l, thrust b, drag d, inertia I_x, I_y, I_z
• Initial rotor speeds: w1–w4 (hover state)
• Sets simulation time step and duration

quadmodel.m

• Computes control inputs u₁–u₄ from motor speeds

• Applies Newton–Euler equations to update:

  • Position (x, y, z)
  • Attitude (ϕ, θ, ψ)
  • Velocities and angular rates

• Euler method used for time integration

quadrun.m

• Main entry point:

  • Initializes state
  • Calls dynamics step for each frame
  • Saves data and calls quadplot

quadplot.m

• Plots position and orientation versus time
• Saves figures to figure1.jpg and figure2.jpg

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🧪 Possible Extensions

• 🧭 PID / LQR Control: Add a control law in quadmodel.m
• 🕹️ Trajectory Tracking: Define time-varying setpoints for position/orientation
• 🎥 3D Animation: Use plot3 or patch to render quadrotor motion
• 📓 Live Script: Convert to .mlx for interactive UI

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📄 License

This project is licensed under the MIT License.

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🙋‍♂️ Credits

Developed by Ardy Seto Priambodo ✉️ [email protected]

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🚀 Citation

If you use this project in academic work, please cite:

@misc{matlab_quadcopter,
  author       = {Ardy Seto Priambodo},
  title        = {MATLAB Quadcopter Simulator},
  year         = {2023},
  howpublished = {\url{https://github.com/2black0/MATLAB-Quadcopter-Dynamics-Simulator}},
  note         = {Based on Francesco Sabatino's thesis at KTH}
}

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Fly safely (virtually)! 🚁