README.md

mep3

Memristor Eurobot Platform based on ROS 2

Table of contents

• mep3
  • Table of contents
  • Getting started
  • Webots world simulation
  • ROS 2 platform
    • Compilaton
    • Running the simulation
    • Navigation 2 stack
    • Testing
    • BehaviorTree
    • Terminal shortcuts

Getting started

# Make sure you have ROS 2 Galactic installed.
# https://docs.ros.org/en/galactic/Installation/Ubuntu-Install-Debians.html

# Source ROS 2
source /opt/ros/galactic/local_setup.bash

# Create a workspace
mkdir -p ~/galactic_ws/src
cd ~/galactic_ws
git clone [email protected]:memristor/mep3.git src/mep3

# Install dependencies
rosdep update
rosdep install --from-paths src --ignore-src

# Build the packages
colcon build

# Source this workspace
source install/local_setup.bash

Please check alternative installation methods here.

Webots world simulation

• Open mep3_simulation/webots_data/worlds/eurobot_2022.wbt in Webots

webots ~/ros2_ws/src/mep3/mep3_simulation/webots_data/worlds/eurobot_2022.wbt

• Stop simulation and set time to 00:00:00
• Save changes
• Commit all changes except for Viewpoint

ROS 2 platform

Compilaton

• Change working directory to ~/ros2_ws
• Install dependencies if there are changes in package.xml files

rosdep install --from-paths src --ignore-src

• Build files (and rebuild on every modification):

colcon build
source ./install/local_setup.bash

Running the simulation

• Run the simulation without the behavior tree:

ros2 launch mep3_bringup simulation_launch.py bt:=false

• Control the robot from another terminal window

source /opt/ros/galactic/local_setup.bash
ros2 run teleop_twist_keyboard teleop_twist_keyboard --ros-args -r cmd_vel:=big/cmd_vel

• Run the simulation with the behavior tree:

ros2 launch mep3_bringup simulation_launch.py

Navigation 2 stack

To launch simulation with nav2 run:

ros2 launch mep3_bringup simulation_launch.py

Open RViz afterwards using:

ros2 launch mep3_bringup rviz_launch.py

Testing

• Change working directory to ~/ros2_ws
• Run the following command:

  source /opt/ros/galactic/local_setup.bash
  colcon test --event-handlers console_cohesion+ --return-code-on-test-failure

BehaviorTree

To edit strategies you can use Groot:

• Install Groot (you can use the AppImage version)
• Edit strategies XML files in mep3_behavior_tree/assets/strategies directory
• Run planner for first_strategy.xml with:

  ros2 run mep3_behavior_tree mep3_behavior_tree first_strategy --ros-args -r __ns:=/big

Terminal shortcuts

We use custom terminal shortcuts to provide better development environment ergonomics.

# Enable terminal shortcuts temporarily
source ~/ros2_ws/src/mep3/docker/config/shortcuts.sh

# Enable terminal shortcuts permanently
echo "source ~/ros2_ws/src/mep3/docker/config/shortcuts.sh" >> ~/.bashrc
source ~/.bashrc

After enabling shortcuts, run command h in the terminal to get familiarized with them.