ubuntu 18.04.6中安装ROS melodic

先将Ubuntu的系统源改为国内源，再按下面步骤进行操作。

1、添加ros源
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

或来自中国的源：

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'

---没试过

2、设置key
sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

3、安装curl

sudo apt-get install curl

4、上面如果添加不成功，可以如下增加key
curl -sSL 'http://keyserver.ubuntu.com/pks/lookup?op=get&search=0xC1CF6E31E6BADE8868B172B4F42ED6FBAB17C654' | sudo apt-key add -

5、更新软件
sudo apt update

6、安装，这里介绍Desktop-Full安装: (Recommended) : ROS, rqt, rviz, robot-generic libraries, 2D/3D simulators, navigation and 2D/3D perception 和 安装rosinstall,便利的工具
sudo apt-get install ros-melodic-desktop-full

sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential

7、解决依赖
sudo rosdep init
rosdep update

8、环境设置
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
source ~/.bashrc

9、测试安装，运行roscore
roscore

10、若正常出现以下信息，说明已经成功安装
    .. logging to /home/ubuntu/.ros/log/cb38e680-dee2-11ea-bae1-70665563e003/roslaunch-nx-1205.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://nx:36773/
ros_comm version 1.14.7

SUMMARY
========

PARAMETERS
 * /rosdistro: melodic
 * /rosversion: 1.14.7

NODES

auto-starting new master
process[master]: started with pid [1215]
ROS_MASTER_URI=http://nx:11311/

setting /run_id to cb38e680-dee2-11ea-bae1-70665563e003
process[rosout-1]: started with pid [1228]
started core service [/rosout]

总结：这个步骤是总结下面两个网址来写的。因为ROS在更新，导致以前的下载方式被改变，所以每次下载老版本的时候应该按新版本的步骤来做，比如下载melodic的步骤要根据noetic的步骤来完成，只是最后下载melodic的步骤按melodic来完成。

ROS入门教程-安装并配置ROS环境（Noetic版本） - 创客智造

ROS入门教程-安装并配置ROS环境（melodic版本） - 创客智造​​​​​​​​​​​​​​