ROSbot Tutorials

Welcome to the ROSbot Tutorials repository! This repository contains detailed instructions for working with the ROSbot 2.0 to complete assignment projects and classwork in the Experimental Robotics course 🚀.

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📚 Table of Contents

1. Prerequisites
2. Getting Started
3. ROS 2 Users
4. Connecting via VPN
5. Support and Troubleshooting

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🛠 Prerequisites

Before you begin, ensure you meet the following requirements:

Hardware:

• Access to a ROSbot 2.0.
• A compatible computer for programming and simulation:
  • Linux Distribution (specifically Ubuntu 20.04) is recommended for compatibility with ROS 1 Noetic and ROS 2 Foxy.
  • Use one of the following methods if you don't have native Linux:
    • Virtual Machine
    • Docker
    • WSL (Windows Subsystem for Linux)
    • Dual Boot PC

Software:

• ROS 1 Noetic and ROS 2 Foxy installed on your computer.

Important

Ensure your hardware and software setup meets the course's requirements to avoid issues during the project.

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🚀 Getting Started

Step 1: Connect to the ROSbot

1. Connect your laptop to the [FRITZ!Box 6850 XU] WiFi or the specific WiFi the robots are connected to.
   • WiFi Password: 06537900605465042712
2. Turn on the ROSbot and wait for about 2 minutes for it to boot up.
3. Copy the IP Address written on the robot. This will be referred to as <ROBOT_IP>.

Note

Ensure your laptop is on the same WiFi network as the ROSbot to establish a connection.

Step 2: SSH into the ROSbot

1. Open a terminal and run the following command to SSH into the robot:

   ssh husarion@<ROBOT_IP>

   • Password: husarion

Step 3: Set Up Parameters on Your Laptop

1. Ensure your laptop is connected to the same WiFi as the ROSbot.
2. Get the IP address of your laptop:

   hostname -I

   • Use the IP starting with 192.168.178.XX if multiple IPs are listed. This will be referred to as <PC_IP>.
3. Open your .bashrc file for editing:

   gedit ~/.bashrc

4. Add the following lines to your .bashrc file:

   export ROS_MASTER_URI=http://<ROBOT_IP>:11311
   export ROS_IP=<PC_IP>

5. Save the file and source it:

   source ~/.bashrc

Step 4: Start the ROSbot

1. Go back to the terminal where you SSH’d into the robot and run:

   roslaunch tutorial_pkg all.launch

2. Open a new terminal on your laptop and run:

   rostopic list

   • Ensure you DO NOT run roscore on your laptop, as the ROSbot is the ROS Master.

Caution

Running roscore on your laptop while connected to the ROSbot will cause conflicts with the ROSbot's master node.

3. You can now use your ROS workspace on your laptop to control the robot.

Step 5: Verify and Test

• Move the robot:

  rosrun teleop_twist_keyboard teleop_twist_keyboard

• View camera feed:

  rosrun image_view image_view image:=/camera/rgb/image_raw _image_transport:=compressed

• Visualize laser scan and TF in RViz:

  rviz

Note

If any of these commands fail due to missing packages, install them using:

sudo apt install ros-noetic-PACKAGE_NAME

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🤖 ROS 2 Users

To use ROS 2 to control the robot, follow these additional steps:

Step 1: Install ROS 2 Foxy

• Follow the instructions here to install ROS 2 Foxy.

Step 2: Install the ros1_bridge Package

Install the ros1_bridge package to enable communication between ROS 1 and ROS 2:

sudo apt install ros-foxy-ros1-bridge

Step 3: Set Up parameter_bridge

1. Create a ROS 1 workspace:

   mkdir -p ~/catkin_ws/src
   cd ~/catkin_ws/src
   catkin_create_pkg load_params
   cd load_params
   mkdir launch params
   touch launch/load_params.launch params/topics.yaml

2. Add the following code to launch/load_params.launch:

   <launch>
     <rosparam command="load" file="$(find load_params)/params/topics.yaml"/>
   </launch>

3. Add the following to params/topics.yaml:

   topics:
     [
       { topic: /tf, type: tf2_msgs/msg/TFMessage, queue_size: 10 },
       { topic: /camera/rgb/image_raw/compressed, type: sensor_msgs/msg/CompressedImage, queue_size: 10 },
       { topic: /cmd_vel, type: geometry_msgs/msg/Twist, queue_size: 10 },
       { topic: /odom, type: nav_msgs/msg/Odometry, queue_size: 50 },
       { topic: /scan, type: sensor_msgs/msg/LaserScan, queue_size: 50 },
     ]

Important

Ensure the correct message types and queue sizes for your application.

4. Compile the workspace:

   cd ~/catkin_ws/
   catkin_make
   source devel/setup.bash

Step 4: Prepare Shells

• Open three terminal shells and source the appropriate environments:
  1. Shell 1:

     source /opt/ros/noetic/setup.bash

     • Use this shell for ROS 1 operations.
  2. Shell 2:

     source /opt/ros/noetic/setup.bash
     source /opt/ros/foxy/setup.bash

     • Use this shell to run the ROS 1 Bridge.
  3. Shell 3:

     source /opt/ros/foxy/setup.bash

     • Use this shell for ROS 2 operations.

Step 5: Start the Parameter Server

• In the shell where ROS 1 was sourced, start the parameter server:

  roslaunch load_params load_params.launch

Step 6: Start the Bridge

• Run the bridge in the terminal with both Noetic and Foxy sourced:

  ros2 run ros1_bridge parameter_bridge

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🌐 Connecting via VPN

To access the ROSbot remotely over the internet through a VPN connection, follow these steps:

Step 1: Request an Authentication Code

1. Contact the Teaching Assistants (TAs) to request an authentication code for the VPN.
2. You will receive a personalized auth key that can only be used once and will expire in 7 days if not used.

Step 2: Set Up the VPN Connection

Note

Ensure you are connected to the internet (e.g., via Eduroam or any other internet connection) before proceeding. Do not connect to the FRITZ!Box network, as it does not provide internet access required for the VPN.

1. Open a terminal and set your authentication key:

   TS_AUTH_KEY=<auth_key_from_TAs>

2. Verify that the auth key is saved successfully:

   echo $TS_AUTH_KEY

   • Ensure the output matches your provided auth key.

Important

Do not run the setup commands inside a Docker container. This setup is intended for native Ubuntu environments, WSL, virtual machines, or dual-boot systems.

3. Run the following command to install the VPN client and establish the connection:

   curl -fsSL https://tailscale.com/install.sh | sh && sudo tailscale up --auth-key=$TS_AUTH_KEY

Step 3: Verify VPN Connection

1. Obtain your VPN IP address:

   hostname -I

   • Look for an IP address starting with 100.xxx.xxx.xxx.

Step 4: Continue with ROSbot Connection

1. SSH into the ROSbot using its VPN IP:

   ssh husarion@<ROS_VPN_IP>

   • Password: husarion

2. Verify the connection:

   • Once connected, you should have access to the ROSbot's terminal over the VPN.

3. Configure Your Environment:

   • Set the ROS Master URI to point to the ROSbot's VPN IP:

     export ROS_MASTER_URI=http://<ROS_VPN_IP>:11311
     export ROS_IP=<YOUR_VPN_IP>

   • Add these environment variables to your .bashrc to make them persistent:

     echo "export ROS_MASTER_URI=http://<ROS_VPN_IP>:11311" >> ~/.bashrc
     echo "export ROS_IP=<YOUR_VPN_IP>" >> ~/.bashrc
     source ~/.bashrc

Optional: Using WSLg for VPN Setup

Tip

WSLg (Windows Subsystem for Linux GUI) allows you to run Linux GUI applications directly on Windows, providing an integrated desktop experience. This is useful if you prefer or need to use Linux tools alongside your Windows environment without setting up a separate virtual machine.

Important

To use WSLg, ensure you are running Windows 10 (version 2004 and higher) or Windows 11. Make sure your Windows installation is up to date.

Step 1: Install WSLg with Ubuntu 20.04

1. Install WSLg by running the following command in an elevated PowerShell or Command Prompt:

   wsl --install -d Ubuntu-20.04

2. Follow the prompts to complete the Ubuntu 20.04 installation, setting up your Linux username and password.

3. Launch Ubuntu 20.04 by searching for "Ubuntu 20.04" in the Start Menu and clicking on the application.

Note

You can also start Ubuntu 20.04 from PowerShell by setting it as the default distro and using the bash command:

1. Set Ubuntu 20.04 as the default WSL distro:

   wsl -s Ubuntu-20.04

2. Launch Ubuntu 20.04 by simply entering bash in PowerShell:

   bash

   • This will open the Ubuntu 20.04 terminal.

Step 2: Proceed with VPN Setup in WSLg

1. Open the Ubuntu terminal from the Start Menu or PowerShell.
2. Follow Step 2: Set Up the VPN Connection as described above within the Ubuntu terminal.

Important

Ensure that you are using WSLg with Ubuntu 20.04 and not running the VPN setup commands inside a Docker container.

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🛠 Support and Troubleshooting

If you encounter any issues:

• Contact the professor.
• Reach out to the tutors on Teams:
  • Alice Nardelli
  • Omotoye Shamsudeen Adekoya
• Open an issue on the GitHub repository.

Warning

Do not attempt to reconfigure the ROSbot's hardware/software unless instructed by a tutor or professor.

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