task_2

Task 2: Getting Started with PX4

Task 2.1

Overview

• Getting started with px4 firmware
• Learning about various modes
• Sending Waypoints to px4 via mavros

Problem Statement

• You need to make the drone in Gazebo to follow 4 waypoints in the mission mode of px4
• Create a rosnode named waypoint_Mission in a python script, which will set the waypoints to be sent to px4
• You need to call the rosservice /mavros/cmd/arming to arm and /mavros/set_mode to set mode of the drone to mission mode
• Then you have to call the rosservice /mavros/mission/push and /mavros/mission/pull to Request parameter from device (or internal cache) and send parameters from ROS to FCU respectively.
• The waypoints are as follows:
  • Takeoff at the home position to 10 meters
  • Go to 19.134641, 72.911706, 10
  • Go to 19.134617, 72.911886, 10
  • Go to 19.134434, 72.911817, 10
  • Go to 19.134423, 72.911763, 10
  • Land at the last coordinate

Resources

Install QGroundControl

• On the command prompt enter:

sudo usermod -a -G dialout $USER
sudo apt-get remove modemmanager -y
sudo apt install gstreamer1.0-plugins-bad gstreamer1.0-libav gstreamer1.0-gl -y

• Logout and login again to enable the change to user permissions.
• Download QGroundControl.AppImage

wget https://s3-us-west-2.amazonaws.com/qgroundcontrol/latest/QGroundControl.AppImage

• Install (and run) using the terminal commands:

chmod +x QGroundControl.AppImage
./QGroundControl.AppImage

Learning Resources

• Highly recommended to go through px4 official documentation (following till Modules & Commands will be enough for this task) and for mavros go through mavros px4 documentation before proceeding with the actual task as the learning curve might be steep in the start.

• This task will require the knowledge of custom modes, custom messages and mavros integration

Problem Statement

• You need to make the drone in Gazebo to follow 4 waypoints in the mission mode of px4
• Create a rosnode named waypoint_Mission in a python script, which will set the waypoints to be sent to px4
• You need to call the rosservice /mavros/cmd/arming to arm and /mavros/set_mode to set mode of the drone to mission mode
• Then you have to call the rosservice /mavros/mission/push and /mavros/mission/pull to Request parameter from device (or internal cache) and send parameters from ROS to FCU respectively.
• The waypoints are as follows
  • Takeoff at the home position to 10 meters
  • Go to 19.134641, 72.911706, 10
  • Go to 19.134617, 72.911886, 10
  • Go to 19.134434, 72.911817, 10
  • Go to 19.134423, 72.911763, 10
  • Land at the last coordinate

Procedure

• Launch the Gazebo world by typing the following command in a terminal

roslaunch task_2 task2_1.launch

• Once the simulation window launches, you should see a drone in the gazebo environment.
• Run your python script in a separate terminal to start sending the waypoints and navigate the drone.

Result

task2_1.webm

Task 2.2

Problem Statement

• You need to put the drone in Offboard mode and make a square of 10m x 10m.
• Takeoff from the ground and give the first setpoint as 0m,0m,10m
• Give the next setpoint as 10m,0m,10m followed by 10m,10m,10m followed by 0m,10m,10m and then back to 0m,0m,10m
• Finally land at the home position and disarm Keep the velocity of drone 5 m/s

Resources

Recommend to go through PX4 Official Documentation, to get details about offboard mode.

Procedure

• Launch the Gazebo world by typing the following command in a terminal

roslaunch task_2 task2_2.launch

Once the simulation window launches, you should see a drone in the gazebo environment.

• Run your python script in a separate terminal to start sending the setpoints and navigate the drone.

Result

task2_2.webm

Quick Navigation

• [Up] Task 1 - Getting Started with ArUco and ROS
• [Down] Task 3 - Pick and Place