ubuntu 18.04 melodic roslaunch :七步使用roslaunch控制两个终端机器人

1,切换目录：

$ roscd beginner_tutorials

2,新建launch子目录：

$ mkdir launch

3，进入子目录：

$  cd launch

4，新建launch文件

$ gedit turtlemimic.launch

5，复制下面源码到turtlemimic.launch，然后保存并退出：

<launch>

  <group ns="turtlesim1">
    <node pkg="turtlesim" name="sim" type="turtlesim_node"/>
  </group>

  <group ns="turtlesim2">
    <node pkg="turtlesim" name="sim" type="turtlesim_node"/>
  </group>

  <node pkg="turtlesim" name="mimic" type="mimic">
    <remap from="input" to="turtlesim1/turtle1"/>
    <remap from="output" to="turtlesim2/turtle1"/>
  </node>

</launch>

6，运行roslaunch：

$ roslaunch beginner_tutorials turtlemimic.launch