mini-quadlib 0.2.0

Python bindings for mini-quadlib: A lightweight C library for quadrotor control

Mini-QuadLib

A lightweight C library for quadrotor control systems, with Python bindings.

Features

• Geometric Controller - SE(3) geometric control for quadrotors
• L1 Adaptive Control - Robust adaptive augmentation for disturbance rejection
• Robotics Utilities - Coordinate transforms, frame conversions, rotation representations
• Lightweight - Requires minimal dependencies
• Cross-platform - C library works anywhere, Python bindings for Linux

Repository Structure

mini-quadlib/
├── include/
│   └── mini_quadlib.h      # Main C header (all API documentation here)
├── src/
│   └── *.c                 # C implementation
├── python/
│   └── mini_quadlib/       # Python package
├── build/                  # Build output (generated)
├── CMakeLists.txt
└── README.md

---

C Library

Building (Linux)

Prerequisites

• CMake >= 3.8
• GCC or Clang

Build Static Library

# Clone the repository
git clone https://github.com/sigma-pi/mini-quadlib.git
cd mini-quadlib

# Create build directory
mkdir build && cd build

# Configure and build
cmake ..
make -j$(nproc)

This produces:

• build/libmini_quadlib.a - Static library

Build Shared Library (for Python bindings)

# Create a virtual environment before building
conda create --name mini_quadlib
conda activate mini_quadlib

# Build
cd /path/to/mini-quadlib
mkdir -p build && cd build
cmake .. -DBUILD_PYTHON=ON
make -j$(nproc)

# Copy .so to package directory
cp libmini_quadlib.so ../python/mini_quadlib/

# Install
cd ../python
pip install -e .

This produces:

• build/libmini_quadlib.so - Shared library

Using the C Library

Include in Your Project

#include "mini_quadlib.h"

int main() {
  // Get library version
  printf("mini-quadlib version: %s\n", quadlib_version());
  
  // Create state and setpoint
  state_t current_state = {
      .pos = {0.0f, 0.0f, 0.0f},
      .vel = {0.0f, 0.0f, 0.0f},
      .quat = {1.0f, 0.0f, 0.0f, 0.0f},  // w, x, y, z
      .omega = {0.0f, 0.0f, 0.0f}
  };
  
  setpoint_t desired = {
      .pos = {1.0f, 0.0f, -1.0f},  // NED frame
      .vel = {0.0f, 0.0f, 0.0f},
      .acc = {0.0f, 0.0f, 0.0f},
      .jerk = {0.0f, 0.0f, 0.0f},
      .snap = {0.0f, 0.0f, 0.0f},
      .yaw = 0.0f,
      .yaw_dot = 0.0f,
      .yaw_ddot = 0.0f
  };
  
  // Controller parameters
  geometric_params_t ctrl_params = {
      .k_p = {1.0f, 1.0f, 2.0f},
      .k_v = {0.5f, 0.5f, 1.0f},
      .k_R = {1.0f, 1.0f, 1.0f},
      .k_W = {0.1f, 0.1f, 0.1f}
  };
  
  quadx_params_t quad_params = {
      .mass = 1.0f,
      .inertia = {0.01f, 0.01f, 0.02f}
  };
  
  // Compute control
  control_4f_t output;
  quadlib_result_t result = geometric_control_fM_fullparam(
      &output, &current_state, &desired, &ctrl_params, &quad_params
  );
  
  if (result == QUADLIB_SUCCESS) {
      printf("Thrust: %.2f, Moments: [%.2f, %.2f, %.2f]\n",
             output.u1, output.u2, output.u3, output.u4);
  }
  
  return 0;
}

Compile Your Program

gcc -I/path/to/mini-quadlib/include \
  -L/path/to/mini-quadlib/build \
  your_program.c -lmini_quadlib -lm -o your_program

C API Reference

All C API documentation is in the header file:

📖 include/mini_quadlib.h

Key sections:

• Data Structures - vector3f_t, quaternion4f_t, state_t, setpoint_t, etc.
• Geometric Control - geometric_control_fM_fullparam()
• L1 Adaptive Control - l1_adaptive_control_fullparam()
• Coordinate Transforms - enu_to_ned(), ned_to_enu(), coordinate_transform_omni()
• Rotation Utilities - Quaternion/Euler/RotationMatrix conversions

---

Python Bindings

Quick Install (from source)

cd mini-quadlib

# Build C library first
mkdir build && cd build
cmake .. -DBUILD_PYTHON=ON
make -j$(nproc)
cd ..

# Install Python package
cd python
pip install -e .

Run Basic Tests

python ./python/tests/test_python_api.py

Quick Test

import mini_quadlib as mql
import numpy as np

print(f"Version: {mql.get_version()}")

# Create a quaternion
q = mql.Quaternion(0.707, 0.0, 0.0, 0.707)
print(f"Quaternion: {q}")

# Coordinate transform
ned = np.array([1.0, 2.0, 3.0])
enu = mql.ned_to_enu(ned)
print(f"NED {ned} -> ENU {enu}")

For detailed Python documentation, see:

📖 python/README.md

---

License

MIT License - see LICENSE for details.

Author

Chengyu Yang ([e-mail])