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>