Robot behavior modeling by using state machines

About project

This project aimed to model robot behaviors by using state machine. YASMIN (yet another state machine) is used as the state machine.

This project has many states such as "starting gazebo world", "SLAM operation", "creating and saving map", "create stations", "navigation between stations" and "charging the robot". We aim to model these behaviors bu using state machines.

Why we use State Machines

Using state machines prevents robots from operating unexpectedly. Robots operate according to state machine design and we do not face any unexpected behavior.

Using state machines for modeling robot behaviors helps us to create modular code structure. The programmer divide the system according to state machine design. Then the programmer defines states for each part and manages these parts with help of state transitions (outcomes).

Using state machines is reliable, sustainable, modular and flexible solution to model robot behaviors.

Screenshots

State Machine Design

Starting Gazebo World

Slam Operation

Navigation

Setup Steps (for Ubuntu 22.04 )

install ROS2 Humble

First of all install ros2 to your computer.

Check this web site for details: https://docs.ros.org/en/humble/Installation.html

# set locale

locale  # check for UTF-8

sudo apt update && sudo apt install locales
sudo locale-gen en_US en_US.UTF-8
sudo update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
export LANG=en_US.UTF-8

locale  # verify settings

# setup sources

sudo apt install software-properties-common
sudo add-apt-repository universe

# add ROS2 GPG key with apt
sudo apt update && sudo apt install curl -y
sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg

# add the repository to your sources list
echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/ros-archive-keyring.gpg] http://packages.ros.org/ros2/ubuntu $(. /etc/os-release && echo $UBUNTU_CODENAME) main" | sudo tee /etc/apt/sources.list.d/ros2.list > /dev/null

# install ros2 packages

sudo apt update
sudo apt upgrade

sudo apt install ros-humble-desktop
sudo apt install ros-humble-ros-base
sudo apt install ros-dev-tools

source ROS2 environment

# sourcing the setup script

# Replace ".bash" with your shell if you're not using bash
# Possible values are: setup.bash, setup.sh, setup.zsh

source /opt/ros/humble/setup.bash

create workspace and src folder

First, go to directory where you want to create your workspace.

Then run these commands:

mkdir -p ros2_ws/src
cd /ros2_ws/src

clone project

Ensure you’re still in the ros2_ws/src directory before you clone.

git clone https://github.com/ragaslan/modeling-robot-behavior-using-YASMIN .

resolve dependencies

From the root of your workspace (ros2_ws), run the following command:

# get rosdep if you do not have
sudo apt-get install python3-rosdep 

# if your rosdep installation has not been initialized yet. Run: 
sudo rosdep init
rosdep update

# cd if you're still in the "src" directory
cd .. # if you are still in the "src" directory otherwise it is not necessary
rosdep install -i --from-path src --rosdistro humble -y

build workspace with colcon

First, install colcon if does not exist

# install colcon if does not exist

sudo apt install python3-colcon-common-extensions

From the root of your workspace (ros2_ws), you can now build your packages using the command:

colcon build

And you will see that colcon has created new directories:

ls

build  install  log  src

source the overlay

First, open new terminal. In the new terminal, source your main ROS 2 environment as the “underlay”, so you can build the overlay “on top of” it:

Source main ROS2 environment

source /opt/ros/humble/setup.bash

Go to your workspace directory

cd /ros2_ws

Source your overlay

source install/local_setup.bash

this is necessary for gazebo

source /usr/share/gazebo/setup.sh

set key environment variables

export ROS_DOMAIN_ID=30
export TURTLEBOT3_MODEL=burger 

set burger model parameter

If you get error when you start navigation, you should set some parameters in the burger yaml file

Check this link: turtlebot/turtlebot4#392

sudo nano /opt/ros/humble/share/turtlebot3_navigation2/param/burger.yaml

# in the yaml file, change the robot_model_type in the line 29;

# from:
# robot_model_type: "differential"

# change that line to :
# robot_model_type: "nav2_amcl::DifferentialMotionModel"

run

Now you can run the package.

ros2 run robot robot_node