Description

This project consists of two Python scripts - a REST server and a REST client - designed to monitor the status of a robot controlled by the Robot Operating System (ROS). The REST server exposes an endpoint to provide the current status of the robot, while the REST client continuously queries this endpoint to display the status in real-time. We are using flask API for a lightweight web framework

Prerequisites

• Ubuntu 20.04

• ROS

• Flask

• Flask-RESTful

• requests

Install the prerequisites and packages before proceeding. This code has been run on Ubuntu 20.04 LTS ROS Noetic.

Installing Turtlebot3

sudo apt-get update
sudo apt-get upgrade
cd ~/catkin_ws/src/
git clone https://github.com/ROBOTIS-GIT/turtlebot3_msgs.git -b noetic-devel
git clone https://github.com/ROBOTIS-GIT/turtlebot3.git -b noetic-devel
cd ~/catkin_ws && catkin_make

Turtlebot3 simulator

~/catkin_ws/src/
git clone https://github.com/ROBOTIS-GIT/turtlebot3_simulations.git
cd ~/catkin_ws && catkin_make

Turtlebot3 packages

sudo apt install ros-noetic-dynamixel-sdk
sudo apt install ros-noetic-turtlebot3-msgs
sudo apt install ros-noetic-turtlebot3 

seting up bashrc

cd
gedit .bashrc

ONCE BASHRC FILE OPENS PASTE THE FOLLOWING LINES IN A NEW LINE

alias burger='export TURTLEBOT3_MODEL=burger'
alias waffle='export TURTLEBOT3_MODEL=waffle'
alias tb3fake='roslaunch turtlebot3_fake turtlebot3_fake.launch'
alias tb3teleop='roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch'
alias tb3='roslaunch turtlebot3_gazebo turtlebot3_empty_world.launch'
alias tb3maze='roslaunch turtlebot3_gazebo turtlebot3_world.launch'
alias tb3house='roslaunch turtlebot3_fake turtlebot3_house.launch'
alias tb3rviz='roslaunch turtlebot3_gazebo turtlebot3_gazebo_rviz.launch'

PASTE THESE AT THE BOTTOM

source /opt/ros/noetic/setup.bash
source /home/*Your pc name*/catkin_ws/devel/setup.bash
export TURTLEBOT_MODEL=waffle
export SVGA_VGPU10=0

dependecies

 sudo apt-get install ros-noetic-joy ros-noetic-teleop-twist-joy \
  ros-noetic-teleop-twist-keyboard ros-noetic-laser-proc \
  ros-noetic-rgbd-launch ros-noetic-rosserial-arduino \
  ros-noetic-rosserial-python ros-noetic-rosserial-client \
  ros-noetic-rosserial-msgs ros-noetic-amcl ros-noetic-map-server \
  ros-noetic-move-base ros-noetic-urdf ros-noetic-xacro \
  ros-noetic-compressed-image-transport ros-noetic-rqt* ros-noetic-rviz \
  ros-noetic-gmapping ros-noetic-navigation ros-noetic-interactive-markers

Steps

Running the simulator

export TURTLEBOT3_MODEL=burger
roslaunch turtlebot3_gazebo turtlebot3_world.launch

Running the teleop(to control the bot)

export TURTLEBOT3_MODEL=burger
roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch

Check if the bot is moving using the 'waxd s ' keys

Running rviz

We need to run rviz to map the world generated in gazeboo

export TURTLEBOT3_MODEL=burger
roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping

• after the world is mapped,save the map
• It will be saved in two files with extensions .yaml and .pgm

map

• Once SLAM node is successfully up and running, TurtleBot3 will be exploring unknown area of the map using teleoperation. It is important to avoid vigorous movements such as changing the linear and angular speed too quickly. When building a map using the TurtleBot3, it is a good practice to scan every corner of the map.

Robot Navigation Instructions

Estimating Initial Pose

1. Initiate Pose Estimation:

   • Click on the "2D Pose Estimate" button available in the RViz menu.
   • On the displayed map, select the approximate location of the robot.
   • Adjust the large green arrow to indicate the robot's orientation.

2. Refine Robot's Position:

   • Launch the keyboard teleoperation node to precisely position the robot.
   • Use keyboard controls to move the robot and align it accurately on the map.
   • Move the robot back and forth to gather surrounding environment data for better localization.
   • To avoid conflicting commands, terminate the keyboard teleoperation node by entering Ctrl + C in the terminal.

Setting Navigation Goal

1. Define Navigation Goal:
   • Access the RViz menu and choose the "2D Nav Goal" option.
   • Select the desired destination on the map.
   • Adjust the green arrow to indicate the direction the robot will face upon reaching the destination.

running Navigation

run the same code for starting the gazeboo world

run the following code to open rviz with the map made.

export TURTLEBOT3_MODEL=burger
roslaunch turtlebot3_navigation turtlebot3_navigation.launch map_file:=$HOME/map.yaml

• Click on 2D Pose estimation and click and drag to match the positon and direction of the bot located in the gazeboo simulation

• Click on the 2D Nav Goal nd drag the final destination point to where the bot must reach

The bot will move to the final point without hitting any obstacles as mapped

Running the Scripts

Running the Server

• Go to your catkin_workspace, eg catkin_ws/src

git clone https://github.com/Saketh-Gurram/robot-rest-api.git
cd ..
catkin_make
roslaunch robot-rest-api server.launch

• the luanch file contains the code to run the server side

Running of clients

cd robot-rest-api
cd src
python read.py

Test cases

• case of accepting the Goal

• case of reaching the Goal

• Case of invalid message

Refrences

SLAM

Simulation