ROS_Training

This is a repo for basic ROS training.

Ubuntu install of ROS Melodic

Recommended for Ubuntu 18.04 Installation tutorial: http://wiki.ros.org/melodic/Installation/Ubuntu Commands to install summary:

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 update
sudo apt install ros-melodic-desktop-full
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc source ~/.bashrc
(optional) sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential

Tutorials

If you are new to Linux: You may find it helpful to first do a quick tutorial on common command line tools for linux. A good one is here. ROS wiki Tutorial

ROS files structures

Workspace, packages strutures, see lab 01 document Create a Workspace and package. Install package from ROS. For example: sudo apt install ros-melodic-calibration-msgs Clone and complie source code package from git.(using packprofile to refresh hte path)

ROS communication

Master, Node, Topic, Message,Servers, see lab 01 document Run a ROS node using python command to demonstrate the communication. commonly used command for topics and node.

Writing a Simple Publisher and Subscriber

Using Python or C++, see lab 01 and lab02 document How to create a customer msg, see lab02 document

Writing a Simple Simple Service and Client

Using Python or C++, see lab 01 and lab03 document Note: ##change mode, change access permission "chmod +x xxx.py" How to create a customer srv, see lab03 document

Lanuch file

Lanuch several nodes and setup some parameters. see lab 01 document

ROS bag file

record and play data, tutorial 17 and 18 at http://wiki.ros.org/ROS/Tutorials

ROS class function

see lab 06 document This is a technique often used in real life robotic systems because it is very convenient to group similar tasks in the same class. For example, you would want to group any ‘Kinematics’ related methods and functions together in the same class, any ‘Computer Vision’ algorithms in a separate class and so on. This approach is much more organised than just creating a different package for every different little task you want to do on your robot If you are using Python, the package structure must follow these rules: 1.The ‘[class_def].py’ file must be in ‘catkin_ws/src/[pkg_name]/src/[pkg_name]/[class_def].py’ 2.We must create a blank python file called ‘init.py’ in the same folder 3.We have to uncomment the ‘catkin_python_setup()’ command in ‘CMakeLists.txt’ 4.We must create a python file called ‘setup.py’ in the same directory as ‘CMakeLists.txt’.

test pull request

This is Liming Client. I created a branch-client-1 branch.

Ok, THanks for your commnets. I will learn the PR process more.

Add something on the remote branch

Add more something on the remote branch

LimingGao/ROS_Training