Attitude Determination and Control System (ADCS) Simulation

Author: Bartosz Polak, Tymoteusz Walczak Date: June 2025 Repository: https://github.com/AitenAndGo/ADCS

Abstract

This project implements a complete Attitude Determination and Control System (ADCS) simulation for a satellite in low Earth orbit. The simulation models closed-loop behavior, incorporating orbital propagation, rotational dynamics, realistic sensor models, signal filtering, and control actuation using the B-dot algorithm. The system is written in Python and produces outputs suitable for further analysis and visualization, including a standalone Unity-based 3D visualization tool for enhanced presentation of the satellite's motion.

Features

• Numerical integration of orbital and rotational dynamics
• Simulation of noisy sensor readings (gyroscope and magnetometer)
• Implementation of a complementary filter for sensor fusion
• B-dot control algorithm for magnetic attitude stabilization
• Generation of analysis plots for attitude, control torques, and sensor data
• Data export to CSV format for external visualization
• Optional launching of a Unity-based 3D visualization application

Installation Instructions

Prerequisites

• Python 3.9 or higher
• Git (for cloning the repository)
• Unity visualization requires Windows OS (optional)

Step-by-Step Setup

1. Clone the repository:

git clone https://github.com/AitenAndGo/ADCS.git
cd ADCS

2. Create a virtual environment (optional but recommended):

python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

3. Install required Python packages:

pip install -r requirements.txt

4. Download the Unity visualization executable:

• Download from: Unity Build (Google Drive)
• Extract the contents of the archive into the root ADCS/ directory.
• Ensure the executable file SateliteSim.exe is located at:

Running the Simulation

To start the simulation and generate plots:

cd adcs_sim
python main.py

This will perform the following actions:

• Run the complete ADCS simulation
• Generate plots of orbit trajectory, Euler angles, angular velocities, control torques, and sensor signals
• Export orientation and position data to .csv files in the Unity visualization directory
• Attempt to launch the Unity visualization tool (if on Windows)

Simulation Description

The simulation includes the following major components:

• Orbit Propagation: Integrates satellite position and velocity using a simplified two-body model.
• Attitude Propagation: Uses quaternion-based integration for rotational motion.
• Sensor Simulation: Adds realistic noise to gyroscope and magnetometer data.
• Complementary Filtering: Combines sensor data to estimate angular velocity and magnetic field.
• Control Law: Implements the B-dot controller to damp rotational motion using magnetorquers.
• Data Export: Outputs orientation and position data in CSV format for visualization purposes.

Unity Visualization

If run on Windows with the Unity executable available, main.py will automatically:

• Export trajectory and attitude data to the Unity app's StreamingAssets folder
• Launch SateliteSim.exe for interactive 3D visualization Ensure Unity files are correctly extracted and present in the project root.

Acknowledgements

This project was developed as part of an academic exploration of spacecraft attitude control. The author acknowledges guidance and resources provided by the university research community and open-source developers in the aerospace and simulation fields.

License

This project is released under the MIT License. See MIT License file for details.