title	emoji	colorFrom	colorTo	sdk	sdk_version	app_file	tags	thumbnail	license	pinned	short_description
Interactive Arm Simulator	🚀	blue	green	gradio	5.36.2	app.py	robotics inverse-kinematics gradio python simulation education visualization arm-simulator interactive STEM	https://cdn-uploads.huggingface.co/production/uploads/653637973da0ff3c70cac1b5/grSqNUonDS7CApHsbnc8U.png	mit	true	Interactive 2-DOF robotic arm simulator with real-time inver

Interactive Arm Simulator

A modern, interactive Gradio app for simulating the inverse kinematics of a 2-DOF (two-degree-of-freedom) robotic arm. Visualize, experiment, and learn the math behind robotic arm movement in real-time!

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🚀 Features

• Live Simulation: Adjust target coordinates (X, Y) and arm lengths (L1, L2) with sliders and see the arm move instantly.
• Visual Feedback: Clear visualization of the arm, joints, and unreachable targets.
• Angle Display: See calculated joint angles (shoulder and elbow) in both radians and degrees.
• Math Explanation: Built-in accordion explains the inverse kinematics formulas.
• Copyable Python Code: Easily grab the core function to use in your own projects.

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🕹️ Controls Preview

Use the sliders to set the arm lengths and target position. The plot updates in real-time.

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📦 Usage

1. Install requirements:

   pip install gradio matplotlib numpy

2. Run the app:

   python app.py

3. Interact:
   • Move the sliders for X, Y, L1, and L2.
   • Watch the arm and joint angles update.
   • Use the "Copy the Core Python Function" dropdown for your own code.

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🧮 How It Works: Inverse Kinematics

This app calculates the joint angles needed for a 2-link arm to reach a target point (x, y) using geometry:

1. Elbow Angle ($q_2$): Uses the Law of Cosines: $$ \cos(q_2) = \frac{x^2 + y^2 - L_1^2 - L_2^2}{2L_1L_2} $$ 2. Shoulder Angle ($q_1$): Combines the angle to the target and the triangle's internal angle: $$ q_1 = \alpha - \beta $$ Where:

• $\alpha = \text{atan2}(y, x)$ (angle to target)
• $\beta = \text{atan2}(L_2 \sin(q_2), L_1 + L_2 \cos(q_2))$ If the target is unreachable, the app shows a warning and marks it in red.

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📝 Copy the Core Python Function

The app includes a dropdown with the following code for your use:

def inver_k(l1, l2, x, y):
    """
    Calculates the joint angles (q1, q2) for a 2-DOF robotic arm.
    Args:
        l1, l2: Lengths of the arm segments
        x, y: Target coordinates
    Returns:
        (success, q1, q2): Whether the point is reachable and the joint angles in radians
    """
    import math
    import numpy as np
    dist_sq = x**2 + y**2
    if dist_sq > (l1 + l2)**2 or dist_sq < (l1 - l2)**2:
        return (False, 0, 0)
    cos_q2 = (dist_sq - l1**2 - l2**2) / (2 * l1 * l2)
    cos_q2 = np.clip(cos_q2, -1.0, 1.0)
    q2 = math.acos(cos_q2)
    alpha = math.atan2(y, x)
    beta = math.atan2(l2 * math.sin(q2), l1 + l2 * math.cos(q2))
    q1 = alpha - beta
    return (True, q1, q2)

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📚 Credits

• Original inverse kinematics logic from ARMv6 by gokul6350
• Adapted and extended as an interactive Gradio app for educational purposes.

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License

MIT