文章参考：http://wiki.ros.org/melodic/Installation/Ubuntu
安装ROS
开始准备安装 ROS 环境。
添加 sources.list
打开终端，输入
sudo sh -c ‘echo “deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main” > /etc/apt/sources.list.d/ros-latest.list’
设置**
打开终端，输入
sudo apt-key adv --keyserver ‘hkp://keyserver.ubuntu.com:80’ --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
安装ROS
更新源，打开终端输入
sudo apt update
安装完整ros包
sudo apt install ros-melodic-desktop-full
环境变量配置
echo “source /opt/ros/melodic/setup.bash” >> ~/.bashrc
source ~/.bashrc
安装ROS依赖包
安装相关依赖包，打开终端输入
sudo apt install python-rosinstall python-rosinstall-generator python-wstool build-essential
sudo apt install python-rosdep
初始化rosdep
sudo rosdep init
rosdep update
启动测试ROS
启动Ros Master
roscore
启动小海龟仿真器
rosrun turtlesim turtlesim_node
启动海龟控制节点
rosrun turtlesim turtle_teleop_key