ROS笔记1 安装及创建一个ROS Package

安装 跟着官方的安装指引来就行了.安装前要先确定自己的ros版本和ubuntu版本.这二者是一一对应的.
http://wiki.ros.org/ROS/Installation

主要是package源换成https://blog.csdn.net/shenghuaijing3314/article/details/76222385这篇文章中提到的中科大的镜像地址. 用官网的源,下载速度超慢.我的本机是带翻墙的,但是虚拟机里的ubuntu不能翻墙,不知道要怎么设置.

sudo sh -c '. /etc/lsb-release && echo "deb http://mirrors.ustc.edu.cn/ros/ubuntu/ $DISTRIB_CODENAME main" > /etc/apt/sources.list.d/ros-latest.list'

Navigating the ROS Filesystem

http://wiki.ros.org/ROS/Tutorials/NavigatingTheFilesystem
基本就是描述一下ros的一些bash怎么用.

Quick Overview of Filesystem Concepts

• Packages: Packages are the software organization unit of ROS code. Each package can contain libraries, executables, scripts, or other artifacts.
• Manifests (package.xml): A manifest is a description of a package. It serves to define dependencies between packages and to capture meta information about the package like version, maintainer, license, etc...

命令行工具

• rospack
• roscd
• rosls

Note that roscd, like other ROS tools, will only find ROS packages that are within the directories listed in your ROS_PACKAGE_PATH. To see what is in your ROS_PACKAGE_PATH, type:

echo $ROS_PACKAGE_PATH

http://wiki.ros.org/rosbash

Creating a ROS Package

What makes up a catkin Package?

• package.xml
• CMakeLists.txt
• Each package must have its own folder 不支持嵌套

最简单的package结构如下

my_package/
  CMakeLists.txt
  package.xml

推荐使用workspace创建package。结构如下

workspace_folder/        -- WORKSPACE
  src/                   -- SOURCE SPACE
    CMakeLists.txt       -- 'Toplevel' CMake file, provided by catkin
    package_1/
      CMakeLists.txt     -- CMakeLists.txt file for package_1
      package.xml        -- Package manifest for package_1
    ...
    package_n/
      CMakeLists.txt     -- CMakeLists.txt file for package_n
      package.xml        -- Package manifest for package_n

Creating a catkin Package

http://wiki.ros.org/catkin/Tutorials/create_a_workspace
首先一此链接里的操作创建一个catkin_ws/src目录.然后执行catkin_make。

$ mkdir -p ~/catkin_ws/src
$ cd ~/catkin_ws/
$ catkin_make

The catkin_make command is a convenience tool for working with catkin workspaces. Running it the first time in your workspace, it will create a CMakeLists.txt link in your 'src' folder. Additionally, if you look in your current directory you should now have a 'build' and 'devel' folder. Inside the 'devel' folder you can see that there are now several setup.*sh files. Sourcing any of these files will overlay this workspace on top of your environment

类似于生成makefile文件之类的.

使用catkin_create_pkg beginner_tutorials std_msgs rospy roscpp创建一个package

# You should have created this in the Creating a Workspace Tutorial
$ cd ~/catkin_ws/src
$ catkin_create_pkg beginner_tutorials std_msgs rospy roscpp

# This is an example, do not try to run this
# catkin_create_pkg <package_name> [depend1] [depend2] [depend3]

$ cd ~/catkin_ws
$ catkin_make

查看package依赖

rospack depends1 beginner_tutorials 

roscd beginner_tutorials
cat package.xml

package.xml里描述了依赖信息等.

依赖的包可能又有自己的依赖,比如

rospack depends1 rospy

genpy
roscpp
rosgraph
rosgraph_msgs
roslib
std_msgs

rospack depends可以显示所有嵌套的依赖

$ rospack depends beginner_tutorials
cpp_common
rostime
roscpp_traits
roscpp_serialization
catkin
genmsg
genpy
message_runtime
gencpp
geneus
gennodejs
genlisp
message_generation
rosbuild
rosconsole
std_msgs
rosgraph_msgs
xmlrpcpp
roscpp
rosgraph
ros_environment
rospack
roslib
rospy

Customizing Your Package

描述一下package.xml各个tag的功能.

• description tag
• maintainer tags
• license tags
• dependencies tags
  • build_depend
  • buildtool_depend
  • exec_depend
  • test_depend

  <buildtool_depend>catkin</buildtool_depend>
    
  #编译时依赖  
  <build_depend>roscpp</build_depend>
  <build_depend>rospy</build_depend>
  <build_depend>std_msgs</build_depend>

  #运行时依赖
  <exec_depend>roscpp</exec_depend>
  <exec_depend>rospy</exec_depend>
  <exec_depend>std_msgs</exec_depend>