ar_drone_wrapper

Overview

This repository contains a ROS package for controlling the Parrot AR Drone 1.0. The package is intended to be used with ROS Melodic and is based on the python-ardrone project.

Installation

To install the package, navigate to your ROS src folder and clone this repository:

cd ~/catkin_ws/src
git clone <repository-url>

Setting Up Virtual Environment

Create a virtual environment and activate it:

virtualenv env
source env/bin/activate

Installing Dependencies

Install the required Python dependencies:

pip install -r requirements.txt

Compiling the Project

Compile the ROS workspace:

cd ~/catkin_ws
catkin_make

Additional Dependencies

The ffmpeg library needs to be installed to receive the drone's camera image:

sudo apt install ffmpeg

Usage

Running the ROS Node

To run the ROS node, execute the following command:

rosrun ar_drone_wrapper drone_driver.py

Topics

The package publishes and subscribes to various ROS topics needed for the drone to work:

• Published Topics:

  • /ardrone/cmd_vel
  • /ardrone/nav_data
  • /ardrone/takeoff
  • /ardrone/land
  • /ardrone/reset
  • /ardrone/odom
  • /ardrone/front_camera/raw_image
  • /ardrone/front_camera/raw_image_compressed
  • /ardrone/altitude
  • /ardrone/battery
  • /ardrone/tf
  • /ardrone/mag

• Subscribed Topics:

  • /ardrone/cmd_vel: Command velocity for controlling the drone.
  • /ardrone/takeoff: Command to make the drone take off.
  • /ardrone/land: Command to make the drone land.
  • /ardrone/reset: Command to reset the drone.

Code Explanation

Importing Libraries

The code imports necessary libraries including ROS for communication, OpenCV for image processing, and the AR Drone library for drone control.

Publisher and Subscriber Setup

The code sets up publishers for navdata and camera images, and subscribers for drone control commands (takeoff, land, reset, and movement).

Helper Functions

• images(drone): Captures and publishes the front camera image of the drone.
• nav_data(drone): Captures and publishes the navigation data of the drone.
• cmd_vel(move_data): Controls the drone's movement based on command velocity messages.
• takeoff(_data): Commands the drone to take off.
• land(_data): Commands the drone to land.
• reset(_data): Commands the drone to reset.

Main Function

The main function initializes the ROS node, connects to the drone, and sets up the necessary subscribers. It then starts the ROS spin loop to keep the node running.

Navdata Structure

The navdata structure contains various telemetry data from the drone, including battery level, altitude, velocity, and orientation.

{
  "vy": 0.0,
  "phi": -3,
  "psi": -115,
  "num_frames": 0,
  "battery": 79,
  "altitude": 0,
  "ctrl_state": 1,
  "vx": 0.0,
  "theta": -1,
  "vz": 0.0,
  "drone_state": {
    "acq_thread_on": 1,
    "angles_out_of_range": 0,
    "ctrl_watchdog_mask": 0,
    "video_mask": 0,
    "com_watchdog_mask": 0,
    "fw_ver_mask": 0,
    "video_thread_on": 1,
    "adc_watchdog_mask": 0,
    "com_lost_mask": 0,
    "control_mask": 0,
    "user_el": 0,
    "atcodec_thread_on": 1,
    "command_mask": 1,
    "user_feedback_start": 0,
    "altitude_mask": 1,
    "fw_file_mask": 1,
    "navdata_thread_on": 1,
    "vbat_low": 0,
    "fly_mask": 0,
    "vision_mask": 0,
    "ultrasound_mask": 0,
    "emergency_mask": 0,
    "fw_upd_mask": 0,
    "pic_version_mask": 1,
    "cutout_mask": 0,
    "navdata_bootstrap": 0,
    "motors_mask": 0,
    "navdata_demo_mask": 1,
    "timer_elapsed": 0
  },
  "vision_flag": 0,
  "seq_nr": 23636
}

TODO

• Debug and fix the navdata publishing issue.
• Add tag detection functionality.

License

This project is licensed under the MIT License.

Contributions

Contributions are welcome! Please fork this repository, make your changes, and submit a pull request.

Contact

For any questions or support, please open an issue in this repository.

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