首先使用管理员权限进行安装，安装然后数据密钥，再进行一个更新操作
1、命令如下：
第一个：sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
第二个：sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
第三个：
sudo apt update
到这步，大部分工具已经安装完毕，但后续还要用到一些工具可能还没下载完全，继续....
2、命令：sudo apt install ros-melodic-desktop-full
输入“y"，根据自己的网速，需要等待安装完成....
3、命令：
sudo rosdep init
rosdep update
遇到问题1：
sudo rosdep init 找不到命令解决办法
先看看到底ros安装成功没有：whereis rosdep
解决办法：sudo apt install python-rosdep2 -y
遇到问题2：
ubuntu安装ROS进行到rosdep update时出现错误，如ERROR: unable to process source ...
解决办法：
sudo gedit /etc/resolv.conf
将原有的nameserver这一行注释，并添加以下两行：
nameserver 8.8.8.8 #google域名服务器
nameserver 8.8.4.4 #google域名服务器
保存退出，执行
sudo apt-get update
再执行
rosdep update
遇到问题3：解决rosdep update一直timeout的问题
错误内容
之前执行rosdep update的时候，就报下面的错误，总的来说就是显示超时。
reading in sources list data from /etc/ros/rosdep/sources.list.d Hit http://github.com/ros/rosdistro/raw/master/rosdep/osx-homebrew.yaml ERROR: unable to process source [http://github.com/ros/rosdistro/raw/master/rosdep/base.yaml]:(http://github.com/ros/rosdistro/raw/master/rosdep/base.yaml) ERROR: error loading sources list: The read operation timed out
解决办法
更改 /usr/lib/python2.7/dist-packages/rosdep2/ 下的三个文件sources_list.py、gbpdistro_support.py、rep3.py中的DOWNLOAD_TIMEOUT = 15.0值，改大一点就可以了。
操作如下
sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/gbpdistro_support.py
注意分别对三个文件进行修改
遇到问题4：如果一直发展是网络问题，可以试试自己手机的热点
遇到问题5：ubuntu 下 解决github访问不了
解决办法：
1、进入终端命令行模式，输入sudo vim /etc/hosts
2、输入i进入编辑命令，英文输入法输入G，vim编辑器跳到hosts文件的最后一行
3、用浏览器访问 IPAddress.com 使用 IP Lookup 工具获得github.com和github.global.ssl.fastly.net域名的ip地址
4、在vi打开的hosts文件中添加如下格式：
192.30.253.112 github.com （根据自己查到的ip地址改写）
151.101.44.249 github.global.ssl.fastly.net （根据自己查到的ip地址改写）后缀可能会有不一样，不用管
5、esc退出编辑模式，输入 ：wq，保存hosts文件，修改hosts结束
6、更新DNS缓存，输入sudo /etc/init.d/networking restart
遇到问题6：rosdep update 时出现错误
错误描述：
reading in sources list data from /etc/ros/rosdep/sources.list.d
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/osx-homebrew.yaml
ERROR: unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml]:
(https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml)
ERROR: unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml]:
(https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml)
ERROR: unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml]:
(https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml)
ERROR: unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/releases/fuerte.yaml]:
Failed to download target platform data for gbpdistro:
Query rosdistro index https://raw.githubusercontent.com/ros/rosdistro/master/index-v4.yaml
Skip end-of-life distro "ardent"
Skip end-of-life distro "bouncy"
Add distro "crystal"
ERROR: error loading sources list:
解决方法：
sudo apt-get update && sudo apt-get install python-rosdep
sudo rosdep init
rosdep update
如果还有错误，，嗯，继续执行 ，直至成功！！
rosdep update
具体详情：ROS- 解决 rosdep update 出现的错误 - it610.com
最后必杀技，自己下载包安装：ros安装，在rosdep update这一步出错，换网也解决不了，不是网络不好的原因，直接下载源文件进行替换
解决方案：
1、git clone
https://github.com/ros/rosdistro
2.cd /home/yourname/rosdistro/rosdep/sources.list.d/
3.sudo gedit 20-default.list
# os-specific listings first
yaml file:///home/yourname/rosdistro/rosdep/osx-homebrew.yaml osx
# generic
yaml file:///home/yourname/rosdistro/rosdep/base.yaml
yaml file:///home/yourname/rosdistro/rosdep/python.yaml
yaml file:///home/yourname/rosdistro/rosdep/ruby.yaml
gbpdistro file:///home/yourname/rosdistro/releases/fuerte.yaml fuerte
4.将文件中的网址替换为你的文件路径，将"raw.githubusercontent.com"修改为/home/yourname/rosdistro/rosdep
下面三个文件中也要修改，修改方式同上，查看你的python2.7
/usr/lib/python2.7/dist-packages/rosdep2/gbpdistro_support.py
/usr/lib/python2.7/dist-packages/rosdep2/rep3.py
/usr/lib/python2.7/dist-packages/rosdistro/__init__.py
sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/gbpdistro_support.py
# FUERTE_GBPDISTRO_URL = 'https://raw.githubusercontent.com/ros/rosdistro/master/releases/fuerte.yaml'
FUERTE_GBPDISTRO_URL = 'file:///etc/ros/rosdistro-master/releases/fuerte.yaml'
sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/rep3.py
# REP3_TARGETS_URL = 'https://raw.githubusercontent.com/ros/rosdistro/master/releases/targets.yaml'
REP3_TARGETS_URL = 'file:etc/ros/rosdistro-master/releases/targets.yaml'
sudo gedit /usr/lib/python2.7/dist-packages/rosdistro/__init__.py
# DEFAULT_INDEX_URL = 'https://raw.githubusercontent.com/ros/rosdistro/master/index-v4.yaml'
DEFAULT_INDEX_URL = 'file:///etc/ros/rosdistro-master/index-v4.yaml'
下面三个文件中也要修改，修改方式同上，查看你的python3
5.cd /usr/lib/python3/dist-packages/rosdep2/
6.sudo gedit gbpdistro_support.py
FUERTE_GBPDISTRO_URL = 'file:///home/yourname/rosdistro/'
'releases/fuerte.yaml'
7.cd /usr/lib/python3/dist-packages/rosdep2/
8.sudo gedit rep3.py
9.cd /usr/lib/python2.7/dist-packages/rosdistro/
10.sudo gedit __init__.py
DEFAULT_INDEX_URL = 'file:///home/yourname/rosdistro/index-v4.yaml'
11.cd /etc/ros/rosdep/sources.list.d
12.sudo gedit 20-default.list
#os-specific listings first
yaml file:///home/yourname/rosdistro/rosdep/osx-homebrew.yaml osx
#generic
yaml file:///home/yourname/rosdistro/rosdep/base.yaml
yaml file:///home/yourname/rosdistro/rosdep/python.yaml
yaml file:///home/yourname/rosdistro/rosdep/ruby.yaml
gbpdistro file:///home/yourname/rosdistro/releases/fuerte.yaml fuerte
同理替换网址
#newer distributions (Groovy, Hydro, ...) must not be listed anymore, they are being fetched from the rosdistro index.yaml instead
再执行rosdep update
详情链接：rosdep update解决方法之一 - 知乎
安装完成后，使用roscore进行测试，发现有报错了
遇到问题7：ROS安装问题： “Command ‘roscore‘ not found, but can be installed with: sudo apt install python-roslaunch“https://blog.csdn.net/tom17/article/details/107748686
遇到问题8：opt文件夹下没有ros_ROS入门教程(一)
最终测试：ROS编程入门系列小结
