工具使用-ROS如何创建Packages

Package的组成部分

Package.xml

该文件主要提供该package的信息描述
CMakeLists.txt

catkin_make所必需的文件

Package结构

Package包必须处在workspace下的src文件夹下，而且Package包允许嵌套。

创建Package

1 2	cd ～/catkin_ws/src catkin_create_pkg beginner_tutorials std_msg rospy roscpp

其中catkin_ws 表示ros的工作空间，其目录下的文件结构

catkin_ws/
	build   % 编译中间件
	devel   % 编译之后的可执行库
	src  % packages, 源码文件包

catkin_create_pkg创建包的指令，见到的为数不多的不是以ros开头的指令.

1	catkin_create_pkg <package_name> [depend1] [depend2] [depend3]

后面三个分别是预导入的几个依赖package。

编译Package

创建Package之后需要对Package进行编译， ros可以使用catkin_mak简单的完成编译。

1 2	cd ~/catkin_ws # 必须在工作空间根目录中执行指令，即src所在的目录 catkin_make

编译完成后，需要重新激活一下工作空间，更新ros的环境变量

1	. ~/catkin_ws/devel/setup.bash

查看Package的依赖包

1	rospack depends1 beginner_tutorials

显示beginner_tutorials所依赖的包

rospy

roscpp

std_msgs

这些依赖包也可以从Package.xml中的依赖项看到

…
roscpp rospy std_msgs
….

而这些依赖包本身也有依赖项，同样可以使用该指令查看

1	rospack depends1 rospy

Package.xml文件

<?xml version="1.0"?>   <!-- xml协议的版本号-->
<package format="2">
  <name>beginner_tutorials</name>  % 这个包的包名
  <version>0.0.0</version>         % 这个包的版本号
  <description>The beginner_tutorials package</description> % 该包的间断描述

  <!-- One maintainer tag required, multiple allowed, one person per tag -->
  <!-- Example:  -->  % 这部分定义了包的维护者信息
  <!-- <maintainer email="jane.doe@example.com">Jane Doe</maintainer> -->
  <maintainer email="jingao@todo.todo">jingao</maintainer>


  <!-- One license tag required, multiple allowed, one license per tag -->
  <!-- Commonly used license strings: -->  % 该包遵循的协议，一般是BSD协议
  <!--   BSD, MIT, Boost Software License, GPLv2, GPLv3, LGPLv2.1, LGPLv3 -->
  <license>TODO</license>


  <!-- Url tags are optional, but multiple are allowed, one per tag -->
  <!-- Optional attribute type can be: website, bugtracker, or repository -->
  <!-- Example: -->  % 该包的一些相关链接
  <!-- <url type="website">http://wiki.ros.org/beginner_tutorials</url> -->


  <!-- Author tags are optional, multiple are allowed, one per tag -->
  <!-- Authors do not have to be maintainers, but could be -->
  <!-- Example: -->  % 作者信息
  <!-- <author email="jane.doe@example.com">Jane Doe</author> -->

 % 下面这部分指定了依赖包信息
  <!-- The *depend tags are used to specify dependencies -->
  <!-- Dependencies can be catkin packages or system dependencies -->
  <!-- Examples: -->
  <!-- Use depend as a shortcut for packages that are both build and exec dependencies -->
  <!--   <depend>roscpp</depend> -->
  <!--   Note that this is equivalent to the following: -->
  <!--   <build_depend>roscpp</build_depend> -->
  <!--   <exec_depend>roscpp</exec_depend> -->
  <!-- Use build_depend for packages you need at compile time: -->
  <build_depend>message_generation</build_depend>   % 这部分如果自定义了msg和srv就需要打开
  <!-- Use build_export_depend for packages you need in order to build against this package: -->
  <!--   <build_export_depend>message_generation</build_export_depend> -->
  <!-- Use buildtool_depend for build tool packages: -->
  <!--   <buildtool_depend>catkin</buildtool_depend> -->
  <!-- Use exec_depend for packages you need at runtime: -->
    <exec_depend>message_runtime</exec_depend>  % 对应着msg和srv的运行时版本
  <!-- Use test_depend for packages you need only for testing: -->
  <!--   <test_depend>gtest</test_depend> -->
  <!-- Use doc_depend for packages you need only for building documentation: -->
  <!--   <doc_depend>doxygen</doc_depend> -->
  <buildtool_depend>catkin</buildtool_depend>
  <build_depend>roscpp</build_depend>
  <build_depend>rospy</build_depend>
  <build_depend>std_msgs</build_depend>
  <build_export_depend>roscpp</build_export_depend>
  <build_export_depend>rospy</build_export_depend>
  <build_export_depend>std_msgs</build_export_depend>
  <exec_depend>roscpp</exec_depend>
  <exec_depend>rospy</exec_depend>
  <exec_depend>std_msgs</exec_depend>


  <!-- The export tag contains other, unspecified, tags -->
  <export>
    <!-- Other tools can request additional information be placed here -->

  </export>
</package>

关于CMakeLists.txt文件后面在介绍。

总结

常用指令：

1
2
3

catkin_create_pkg  <包名> 依赖1 依赖2 依赖3 依赖4
rospack depends1 <package_name>  # 查看包的依赖包
rospack find <package_name>  # 找到包的绝对路径