Lecture

ROS - Robot Operating System

06 Oct 2024 • Richard Kuo

The Robot Operating System (ROS) is a set of software libraries and tools that help you build robot applications.

ROS簡介

ROS簡介及教學資源整理
他其實是安裝在Linux的環境上面.(Linux系統—架構淺析)
ROS比較像是在負責為機器人的各個元件進行溝通與操作的一個框架，以機器人的行走為例，要讓機器人走路需要控制其底下的馬達、還有一些感測器以進行避障等等， ROS內就有這種類型的函式可以讓控制馬達的程式得以與接收感測器的程式溝通，如下圖所示:

ROS-based communication architecture

Paper: A ROS2 based communication architecture for control in collaborative and intelligent automation systems

ROS is a collection of tools and libraries that aids robotics software development. Software is written in form of nodes that exchange messages using a transport layer called TCPROS based on standard TCP/IP sockets.

ROS has a centralized network configuration which means that there has to exist a running ROS master. To improve on this design limitation, developers of ROS2 implemented Object Management Group’s standard DDS as the communication middleware considering it to be scalable, robust and well-proven in mission-critical systems.

An Automated Guided Vehicle (AGV) carrying a diesel truck engine and an autonomous mobile platform (MiR100) carrying kitted material to be assembled on an engine enter the Collaborative Robot Assembly Station.

Robots using ROS

TurtleBot

TurtleBot3 手冊

ROS distro

List of Distributions

ROS Noetic Ninjemys on Ubuntu 20.04 (Recommended for Latest ROS 1 LTS) Install
ROS Foxy Fitzroy on Ubuntu 20.04, macOS (10.14), or Windows (VS2019) (Recommended for Latest ROS 2 LTS) Install
ROS Humble Hawksbill on Ubuntu 22.04, macOS, or Windows (VS2019) (Recommended for Latest ROS 2) Install

Noetic Ninjemys	Foxy Fitzroy	Humble Hawksbill

ROS on DDS

The Data Distribution Service (DDS) for real-time systems is an Object Management Group (OMG) machine-to-machine (sometimes called middleware or connectivity framework) standard that aims to enable dependable, high-performance, interoperable, real-time, scalable data exchanges using a publish–subscribe pattern.

DDS addresses the needs of applications like aerospace and defense, air-traffic control, autonomous vehicles, medical devices, robotics, power generation, simulation and testing, smart grid management, transportation systems, and other applications that require real-time data exchange.

DDS has been used in:

battleships
large utility installations like dams
financial systems
space systems
flight systems
train switchboard systems

DDSI-RTPS
DDSI: DDS Interoperability Wire Protocol RTPS: Real-Time Publish-Subscribe protocol The DDS interoperability demonstration used scenarios such as:

Basic connectivity to network using Internet Protocol (IP)
Discovery of publishers and subscribers
Quality of service (QoS) Compatibility between requester and offerer
Delay-tolerant networking
Multiple topics and instances of topics
Exclusive ownerships of topics
Content filtering of topic data including time and geographic

In 2004, the Object Management Group (OMG) published DDS version 1.0.

Ubuntu22.04 on Windows 11

在Windows 10 使用WSL2 安裝Linux系統
 WSL 的基本命令

啟用 Windows子系統Linux 與虛擬機器平台

Open PowerShell as administrator (管理者權限)

啟用 Windows 子系統 Linux

dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart

啟用虛擬機器平台

dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart

更新wsl
```
wsl --status
wsl --update
```
設WSL2為預設版本
```
wsl --set-default--version 2
wsl -l -v
```

安裝Microsoft商店的 Ubuntu 22.04 LTS

export Ubuntu for backup

Open PowerShell as adminstrator

wsl --shutdown
wsl -l -v
cd D:\WSL\Backup
wsl --export Ubuntu-22.04 ubuntu_backup.tar

How to move existing WSL installation to D: drive

move C:\Users\username\AppData\Local\Packages\CanonicalGroupLimited.Ubuntu22.04LTS_79rhkp1fndgsc\LocalState\ext4 to D:\WSL\Working

Reset User Password if forgotten

run Command-Prompt
ubuntu config --default-user root
run Ubuntu
passwd user_name
Command-Prompt
ubuntu config --default-user user_name

Xserver for Win11 display

Download & Install MobaXterm
Run MobaXterm to find DISPLAY ip-address from X-server icon at upper-right corner
set DISPLAY ip-address in ~/.bashrc
nano ~/.bashrc # add 3 lines below
export DISPLAY=192.168.0.20:0
export LIBGL_ALWAYS_INDIRECT=
export LIBGL_ALWAYS_SOFTWARE=1

Ubuntu22.04 on RPi4

ROS

ROS Noetic for Ubuntu20.04
(kinetic=16.04, melodic=18.04, noetic=20.04)

Ubuntu install of ROS Noetic

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
sudo apt-get update
export ROS1_DISTRO=noetic # kinetic=16.04, melodic=18.04, noetic=20.04
sudo apt-get install ros-$ROS1_DISTRO-desktop-full
sudo apt-get install python3-catkin-tools python3-osrf-pycommon # ubuntu 20.04
sudo apt-get install libeigen3-dev libboost-all-dev libceres-dev

Environment setup

echo "alias source_ros1=\"source /opt/ros/$ROS1_DISTRO/setup.bash\"" >> ~/.bashrc
source ~/.bashrc

source_ros1

Tutorial: Understanding Nodes

sudo apt-get install ros-noetic-turtlesim
Open 6 Terminals to run the following:

ros master
```
source_ros1
roscore
```
list nodes & optics
```
source_ros1
rosnode list
```
rosnode info /rosout
rostopic list

turtlesim node

source_ros1
rosrun turtlesim turtlesim_node

Make the turtle move by arrow-keys

source_ros1
rosrun turtlesim turtle_teleop_key

print a publishing topic

source_ros1
rostopic echo /turtle1/cmd_vel

Make the turtle move in a circle (Ctrl-C to stop)

source_ros1
rostopic pub -r 1 /turtle1/cmd_vel geometry_msgs/Twist -- '[2.0, 0.0, 0.0]' '[0.0, 0.0, 1.8]' 

ROS Tutorials

Navigating the ROS Filesystem

sudo apt-get install ros-noetic-ros-tutorials

rospack find [package_name]
rospack find roscpp
roscd [package_name/subdir]
roscd roscpp
ROS_PACKAGE_PATH
echo $ROS_PACKAGE_PATH
/opt/ros/noetic/share
rosls [package_name/subdir]
rosls roscpp_tutorials

Creating Package: Beginner_Tutorials with talker & listener

source_ros1
mkdir -p ~/catkin_ws/src

Initialize workspace
```
cd ~/catkin_ws
catkin init
```
If you can not initialize workspace to ~/catkin_ws, then rm -rf ~/.catkin_tools

Create package

cd src
catkin_create_pkg beginner_tutorials std_msgs rospy roscpp --rosdistro noetic

Create talker.cpp & listener.cpp

cd beginner_tutorials/src
wget https://raw.github.com/ros/ros_tutorials/kinetic-devel/roscpp_tutorials/talker/talker.cpp
wget https://raw.github.com/ros/ros_tutorials/kinetic-devel/roscpp_tutorials/listener/listener.cpp

Modify CMakeLists.txt for talker & listener

cd ..
mv CMakeLists.txt CMakeLists.txt.0
wget https://raw.github.com/ros/catkin_tutorials/master/create_package_pubsub/catkin_ws/src/beginner_tutorials/CMakeLists.txt

Create messages & services

mkdir msg
echo "int64 num" > msg/Num.msg
mkdir srv
roscp rospy_tutorials AddTwoInts.srv srv/AddTwoInts.srv

Using catkin_make to compile
```
cd ~/catkin_ws
catkin_make
```
Using catkin build to compile
```
cd ~/catkin_ws
catkin build
```

Exercise: Talker & Listener

ROS master
```
source_ros1 
roscore
```

Talker

source_ros1
cd ~/catkin_ws
source devel/setup.bash
rosrun beginner_tutorials talker

Listener

source_ros1
cd ~/catkin_ws
source devel/setup.bash
rosrun beginner_tutorials listener

Gym-Gazebo

an extension of the initial OpenAI gym for robotics using ROS and Gazebo

GazeboCircuit2TurtlebotLidar-v0	GazeboCircuitTurtlebotLidar-v0

GazeboCartPole-v0	GazeboModularArticulatedArm4DOF-v1

GazeboModularScara4DOF-v3	GazeboModularScara3DOF-v3	GazeboModularScara3DOF-v2

ARIACPick-v0

ROS Developement Studio (RDS)

exploring-ros-2-wheeled-robot-part-01

ROS2

install ROS2 on ubuntu20.04 LTS

install ROS2 on Ubuntu22.04 LTS

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

sudo apt update && sudo apt install curl gnupg lsb-release
sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg

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

sudo apt update
sudo apt upgrade

# Desktop Install (Recommended): ROS, RViz, demos, tutorials.
sudo apt install ros-humble-desktop

echo "alias source_ros2=\"source /opt/ros/humble/setup.bash\"" >> ~/.bashrc
source ~/.bashrc

To uninstall it

sudo apt remove ~nros-humble-* && sudo apt autoremove

you may also want to remove the repository:

sudo rm /etc/apt/sources.list.d/ros2.list
sudo apt update
sudo apt autoremove
# Consider upgrading for packages previously shadowed.
sudo apt upgrade

ROS2 Tutorials

Try examples

source /opt/ros/humble/setup.bash

test mutlicasting

ros2 multicast receive

ros2 multicast send

If can not receive multicast, then run ufm as follows

sudo ufw allow in proto udp to 224.0.0.0/4
sudo ufw allow in proto udp from 224.0.0.0/4

Talker-Listener

On one terminal

source /opt/ros/humble/setup.bash
ros2 run demo_nodes_cpp talker

In another terminal

source /opt/ros/humble/setup.bash
ros2 run demo_nodes_py listener

Understanding ROS2 Nodes

sudo apt-get install ros-galactic-turtlesim (for Ubuntu20.04 LTS)
sudo apt-get install ros-humble-turtlesim (for Ubuntu22.04 LTS)

Open 3 Terminals to run the following: