Turtlebot_3_PID

ROS package to simulate Turtlebot 3 Waffle/ Burger in Gazebo. The turtlebot starts at a random position and goes to the goal position input by the user.

YouTube video explanation: https://youtu.be/znWkFWk76XQ

Running instructions

First of all, copy the package control_bot in the src folder of your workspace. Then do:

cd ~/your_workspace
# our workspace in this case is the "catkin_ws"
catkin_make

To launch roscore:-

#source ~/catkin_ws/devel/setup.bash #for bash users
source ~/catkin_ws/devel/setup.zsh
export TURTLEBOT3_MODEL=waffle #for waffle
roslaunch turtlebot3_gazebo turtlebot3_empty_world.launch

To run the python file, do:

#source ~/catkin_ws/devel/setup.bash #for bash users
source ~/catkin_ws/devel/setup.zsh
#to make the python file executable:-
cd ~/catkin_ws/src/control_bot/Scripts
chmod +x final.py 
#then run the python file:-
rosrun control_bot final.py
#rosrun control_bot PID_test1.py   #only if you want to test it

Enter the ranges for generating the random start and end poses. The turtlebot will go to the goal position using a PID controller.

Note for an older version - The command roslaunch control_bot gazebo_user.launch x_pos:={0} y_pos:={1} z_pos:={2} is executed by using subprocess.Popen in the python code file "final.py" in the src folder of control_bot.

Installation of required packages for ROS Melodic

The following packages need to be installed first:-

$ sudo apt-get install ros-melodic-ar-track-alvar
$ sudo apt-get install ros-melodic-ar-track-alvar-msgs

Go to the source folder of the catkin_ws workspace:-

cd ~/catkin_ws/src/ 

Then, clone the following repositories into your workspace:-

git clone https://github.com/ROBOTIS-GIT/turtlebot3.git
git clone https://github.com/ROBOTIS-GIT/turtlebot3_msgs.git  
git clone https://github.com/ROBOTIS-GIT/turtlebot3_applications_msgs.git  
git clone https://github.com/ROBOTIS-GIT/turtlebot3_simulations.git 
#git clone https://github.com/ROBOTIS-GIT/turtlebot3_applications.git  

Change the working directory to catkin_ws and then use catkin_make:-

cd ~/catkin_ws && catkin_make

Reference - ROS Robot Programming book - Page 285 - https://www.pishrobot.com/wp-content/uploads/2018/02/ROS-robot-programming-book-by-turtlebo3-developers-EN.pdf

Install these packages:-

sudo apt-get install ros-melodic-teleop-twist-keyboard  
sudo apt-get install ros-melodic-turtlebot3
sudo apt-get install ros-melodic-joy ros-melodic-joystick-drivers ros-melodic-teleop-twist-joy

To source the catkin workspace if you're using bash:-

source devel/setup.bash

To source the catkin workspace if you're using zsh:-

source ~/catkin_ws/devel/setup.zsh

Then, export the type of Turtlebot 3 that you want.

export TURTLEBOT3_MODEL=waffle #for waffle  
export TURTLEBOT3_MODEL=burger #for burger  

To open empty world in gazebo with Turtlebot3 in it:-

roslaunch turtlebot3_gazebo turtlebot3_empty_world.launch  

Moving the Turtlebot

We can move the turtlebot by:-

1. Publishing to the concerned topics
2. Using teleop.launch which takes inputs from the user using the keyboard.

By publishing to the topic /cmd_vel

1. To control the velocity of the robot, we publish to the topic /cmd_vel.
2. Use the command rostopic info /cmd_vel to see the type of message required to be sent to the topic, the publishers to the topic and the subscribers to the topic.
3. Use rosmsg show geometry_msgs/Twist to see the details of the message type.
4. Then use the command to enter the velocities manually:-

rostopic pub /cmd_vel geometry_msgs/Twist "linear:
  x: 0.0
  y: 0.0
  z: 0.0
angular:
  x: 0.0
  y: 0.0
  z: 0.0"

By controlling the robot using the keyboard

We can use the keyboard_teleop.launch file to control the Turtlebot 3 using inputs from the keyboard using the commands:-

export TURTLEBOT3_MODEL=burger #for burger
roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch

You will get the following menu:-

Run final.py by going into:-

~/catkin_ws/src/Turtlebot3/control_bot/src$

Installation of required packages for ROS kinetic

ROS package to simulate Turtlebot 3 Waffle/ Burger in Gazebo. The turtlebot starts at a random position and goes to the goal position input by the user.

The following packages need to be installed first:-

$ sudo apt-get install ros-kinetic-ar-track-alvar
$ sudo apt-get install ros-kinetic-ar-track-alvar-msgs

Go to the source folder of the catkin_ws workspace:-

cd ~/catkin_ws/src/ 

Then, clone the following repositories into your workspace:-

 
git clone https://github.com/ROBOTIS-GIT/turtlebot3.git   
git clone https://github.com/ROBOTIS-GIT/turtlebot3_msgs.git   
git clone https://github.com/ROBOTIS-GIT/turtlebot3_applications_msgs.git  
git clone https://github.com/ROBOTIS-GIT/turtlebot3_simulations.git  
git clone https://github.com/ROBOTIS-GIT/turtlebot3_applications.git  

Change the working directory to catkin_ws and then use catkin_make:-

cd ~/catkin_ws && catkin_make

Reference - ROS Robot Programming book - Page 285 - https://www.pishrobot.com/wp-content/uploads/2018/02/ROS-robot-programming-book-by-turtlebo3-developers-EN.pdf

Install these packages:-

sudo apt-get install ros-kinetic-teleop-twist-keyboard  
sudo apt-get install ros-kinetic-turtlebot3
sudo apt-get install ros-kinetic-joy ros-kinetic-joystick-drivers ros-kinetic-teleop-twist-joy
sudo apt-get install ros-kinetic-turtlebot-bringup ros-kinetic-turtlebot-navigation ros-kinetic-rtabmap-ros

To source the catkin workspace if you're using bash:-

source devel/setup.bash

To source the catkin workspace if you're using zsh:-

source ~/catkin_ws/devel/setup.zsh

Then, export the type of Turtlebot3 that you want.

export TURTLEBOT3_MODEL=waffle #for waffle  
export TURTLEBOT3_MODEL=burger #for burger  

To open empty world in gazebo with Turtlebot3 in it:-

roslaunch turtlebot3_gazebo turtlebot3_empty_world.launch  

Moving the Turtlebot

We can move the turtlebot by:-

1. Publishing to the concerned topics
2. Using teleop.launch which takes inputs from the user using the keyboard.

To display messages being published to a topic

rostopic echo /topic_name
#for example, looking at /odom topic for odometry:
rostopic echo /odom 

By publishing to the topic /cmd_vel

1. To control the velocity of the robot, we publish to the topic /cmd_vel.
2. Use the command rostopic info /cmd_vel to see the type of message required to be sent to the topic, the publishers to the topic and the subscribers to the topic.
3. Use rosmsg show geometry_msgs/Twist to see the details of the message type.
4. Then use the command to enter the velocities manually:-

rostopic pub /cmd_vel geometry_msgs/Twist "linear:
  x: 0.0
  y: 0.0
  z: 0.0
angular:
  x: 0.0
  y: 0.0
  z: 0.0"

By controlling the robot using the keyboard

We can use the keyboard_teleop.launch file to control the Turtlebot 3 using inputs from the keyboard using the commands:-

export TURTLEBOT3_MODEL=burger #for burger
roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch

You will get the following menu:-

Run final.py by going into:-

~/catkin_ws/src/Turtlebot3/control_bot/src$

Recording and playing rosbag files

#to record a rosbag file
rosbag record -a

#to play the rosbag file and see it in rviz
#in first terminal
rosparam set /use_sim_time "true"
#toggle spacebar to play/pause the rosbag file
rosbag play --pause -l --clock 2020-09-23-21-46-48.bag
#in another terminal
rviz rviz

References:-

1. Robot Ignite Academy: Mastering with ROS: Turtlebot3
2. ROS Robot Programming book - Page 285 - https://www.pishrobot.com/wp-content/uploads/2018/02/ROS-robot-programming-book-by-turtlebo3-developers-EN.pdf