Code Suite of RQT GUI for multi-drone flight (px4/mavros based)

Youtube videos

• 2 min manual for gui Youtube
• 2 min manual for trajectory creation Youtube

Installation

Ubuntu 16.04 (ROS kinetic), 18.04 (ROS melodic) and 20.04 (ROS noetic) were tested. This package can be either installed by .sh file, or step-by-step manual installation.

Option A: shell script installation.

We assume you have catkin workspace ~/catkin_ws in catkin build system.

sudo chmod 777 install.sh
./install.sh

You might have to reboot system to use mavros

Option B: manual step-by-step installation

• qpOASES

  git clone https://github.com/coin-or/qpOASES.git
  cd path/to/qpOASES
  mkdir build && cd build
  cmake .. -DCMAKE_CXX_FLAGS=-fPIC
  sudo make install
  

  qpOASES is quadratic programming (QP) solver. px4_code generates the flight trajectory based on QP to produce input-efficient flight for drones by optimizing the high order-derivatives of the entire path. The key principle can be found in traj_gen (you don't have to install the pacakge).

• mavros-*

  cd ~/catkin_ws/src
  git clone https://github.com/icsl-Jeon/px4_code2.git
  cd px4_code2
  

  sudo apt-get install ros-${ROS_DISTRO}-mavros ros-${ROS_DISTRO}-mavros-msgs ros-${ROS_DISTRO}-mavros-extras 
  sudo chmod +x ./resource/install_geographic.sh 
  sudo ./resource/install_geographic.sh
  sudo usermod -a -G dialout <user>
  sudo usermod -a -G tty <user>
  sudo reboot
  

  This package was desinged to flight of the drones which has pixhawk FCU and an onboard computer (e.g. upboard or NUC). We assume that the drones can be provided with their odometry information and run mavros for the communicate with GCS (e.g. your laptop).

• px4_code2

  cd ~/catkin_ws/src
  git clone https://github.com/icsl-Jeon/px4_code2_msgs.git
  catkin build px4_code2_msgs
  catkin build px4_code2
  

  • Note: if you want to use catkin build in Noetic, run the following command:

  sudo apt-get install python3-catkin-tools python3-osrf-pycommon
  

Quick start for client rqt node in GCS (e.g. your commander laptop)

If you try to load the dashboard of px4_code2, follow

Option 1. Run fresh px4_code2 via rqt_gui

Like any other rqt node, px4_code2 can be loaded in rqt_gui node.

rosrun rqt_gui rqt_gui --force-discover

Load by Plugins > Robot Tools > FelipeSuite.

Option 2. Roslaunch by importing preset *.perspective file and *.ini qt settings

kinectic ~ melodic

roslaunch px4_code2 client.launch is_noetic:=false

noetic

roslaunch px4_code2 client.launch 

Setup

To use px4_code2 in your multi-drone flight, you have a few things to be set in your GCS and drones' computer.

Step 1. Client side (your GCS)

An example of client.launch is shown below.

    <node name = "rqt_client" pkg = "rqt_gui" type = "rqt_gui"
          args="--perspective-file $(arg client_perspective)" output="screen">
        <rosparam param="/drone_name_set">[target1,target2]</rosparam>
        <rosparam param = "/world_frame_id">"map" </rosparam>
        <rosparam param="/qt_setting_dir" subst_value="True">$(find px4_code2)/qt_settings/setting.ini</rosparam>
    </node>

Parameters for client node

• /drone_name_set : a list of name of drones used for the flight (up to three). The names should be matched with the name in each launch of drone.
• /world_frame_id : the name of world frame. The tf should be fully connected so that the reference frame of the odometry (fraome_id of header field of odometry).
• /qt_setting_dir : this is the setting file (.ini) containing the values in rqt gui. This file is loaded at every open of rqt gui, and saved at every normal termination.

Step 2. Server side (drones)

In setting up the server side, you have to provide the odometry topic and static transform from world_frame_id to the reference frame of the odometry. Also, [mavros] should be running in the onboard computer of the drone in the group namespace drone_name.

An example of launch can be found here: server_t265.launch where Intel realsense t265 was used to collect odometry topic. In the example, t265 is mounted in the opposite direction from the pixhawk.

1. Pixhawk setup of your drone

px4_code2 was designed for the pixhawk setup where the mavros/vision_pose/pose is used for EKF2 fusion yielding mavros/local_position/pose.

Thus, pixhawk should have the following paramters:

• EKF2_AID_MASK = position + yaw
• EKF2_HGT_MODE = vision

2. Odometry setup

px4_code2 subscribes odometry from other packages such as realsense to cater the above pixhawk setting. Basically, px4_code2 receives the odometry and re-publish it as geometry_msgs/PoseStamped topic, which is represented with respect to world_frame_id. by using tf.

For stable EKF2, x-axis of incoming odometry should be aligned with the direction of pixhawk heading.

3. ROS setup

(1) paramteters for server node

• ~drone_name : the name of the considered drone. This is also the group namespace when launching the server.
• yaw_from_px4_to_sensor : the relative yaw angle from pixhawk to the heading direction of the incoming odometry.

(2) Subscribed ros topics for server node

• /<drone_name>/t265/odom/sample : the incoming odometry topic from an external node. The frame_id in the header of the topic should be connected to world_frame_id in tf
• /<drone_name>/mavros/state : the state information of the pixhawk via mavros. This is used to identify whether the drone is in offboard mode or manual.
• /<drone_name>/mavros/local_position/pose : this is the final fused mavros pose (w.r.t world_frame_id) as the output of EKF2 fusion algorithm of pixhawk. This pose is used as the current pose.

Features

Basic flight

• Takeoff : we use the yaw angle state when called takeoff service. Auto - triggered once mission uploaded. StartPose = curMavrosPose / Final pose = height in ui
• Lock : Set cur pose as cur desired pose (NOTE = /mavros pose). If mission exists, deactivates it.
• Resume : If mission exists, re-activates it.
• Land : starting pose = cur mavros pose / desired height = 0

Trajectory following (TBD)