Backend for 3-DOF Robotic Arm Inverse Kinematics

This backend application provides the calculations required for inverse kinematics of a 3-DOF robotic arm. It communicates with the frontend via WebSocket and computes the joint angles and trajectory points based on input coordinates and configuration.

---

Features

• Calculates joint angles (( heta_1, heta_2, heta_3)) using inverse kinematics formulas.
• Computes and sends transformation matrices and joint coordinates.
• Handles real-time WebSocket communication with the frontend.
• Utilizes FastAPI for lightweight and high-performance backend implementation.

---

Installation

1. Clone the repository:

   git clone https://github.com/yourusername/backend-repo-name.git

2. Navigate to the project folder:

   cd backend-repo-name

3. Create a virtual environment and activate it:

   python -m venv env
   source env/bin/activate  # For Windows, use env\Scripts\activate

4. Install dependencies:

   pip install -r requirements.txt

5. Run the server:

   uvicorn main:app --reload --host 0.0.0.0 --port 8000

---

How It Works

1. Input:

   • Accepts target coordinates ((X, Y, Z)) and configuration options (arm and elbow) from the frontend via WebSocket.

2. Inverse Kinematics Calculations:

   • Computes joint angles using trigonometric equations and robot parameters.
   • Transformation matrices ((T_{0_1}, T_{0_2}, T_{0_3}, T_{0_4})) are calculated to determine joint positions.

3. Output:

   • Returns the calculated joint angles and joint coordinates as JSON data to the frontend for visualization.

---

Endpoints

• WebSocket Endpoint: /ws
  • Handles real-time communication between the frontend and backend.

---

Technologies Used

• Python: Programming language.
• FastAPI: Framework for building the backend.
• SymPy: Library for symbolic mathematics, used for matrix operations.
• Uvicorn: ASGI server for running FastAPI.

---

Example Input/Output

Input:

{
  "X": -149.09,
  "Y": 848.20,
  "Z": 20.23,
  "arm": -1,
  "elbow": -1
}

Output:

{
  "theta1_deg": 30.0,
  "theta2_deg": 45.0,
  "theta3_deg": 60.0,
  "coords_0_1": [100.0, 200.0, 300.0],
  "coords_0_2": [150.0, 250.0, 350.0],
  "coords_0_3": [200.0, 300.0, 400.0],
  "coords_0_4": [250.0, 350.0, 450.0]
}

---

License

This project is licensed under the Mozilla Public License Version 2.0