ubuntu18.04.02安裝ROS melodic

　　不一樣的ROS版本所需的ubuntu版本不一樣，每一版ROS都有其對應版本的Ubuntu，切記不可隨便安裝，聽說國際上ROS系統支持最廣的系統分別爲indigo、kinetic。具體可看ros官網http://wiki.ros.org/melodic/Installation/Ubuntu

　　如下是到2018年各個版本ROS對應ubuntu版本對照表：

ROS版本	Ubuntu版本
ROS Melodic Morenia	Ubuntu 18.04（Bionic）/Ubuntu 17.04 Artful
ROS Lunar Loggerhead	Ubuntu 17.04 (Zesty)/Ubuntu 16.10 Yakkety, Ubuntu LTS 16.04 Xenial
ROS Kinetic Kame	Ubuntu 16.04 (Xenial) / Ubuntu 15.10 (Wily)
ROS Jade Turtle	Ubuntu 15.04 (Wily) / Ubuntu LTS 14.04 (Trusty)
ROS Indigo Igloo	Ubuntu 14.04 (Trusty)
ROS Hydro Medusa	Ubuntu 12.04 LTS (Precise)
ROS Groovy Galapagos	Ubuntu 12.04

我這裏選擇的是Melodic版本，具體安裝步驟以下：

1. 設置軟件源

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

2.設置密鑰

sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key 421C365BD9FF1F717815A3895523BAEEB01FA116

3.更新源地址

sudo apt-get update

我這裏在更新源時報錯以下：

W: GPG error: http://packages.ros.org/ros/ubuntu bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654 E: The repository 'http://packages.ros.org/ros/ubuntu bionic InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

解決方法：

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F42ED6FBAB17C654

而後再次更新源地址，問題解決。

sudo apt-get update

PS：在運行上述命令以後，終端會輸出一些相應的信息，注意看有沒有錯誤和告警信息，若是全是獲取和命中就說明沒有問題。

4：安裝ros，在這裏能夠選擇完整版,也能夠選擇只安裝一部分，具體的命令在官網教程中能夠找到。我這裏選擇的是安裝全部，這個過程會比較長

sudo apt-get install ros-melodic-desktop-full

5：初始化rosdep

sudo rosdep init

執行完成以下圖提示進行更新

Wrote /etc/ros/rosdep/sources.list.d/20-default.list Recommended: please run rosdep update

6：按照提示進行update

rosdep update

執行完成以下：

reading in sources list data from /etc/ros/rosdep/sources.list.d Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/osx-homebrew.yaml Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml Hit https://raw.githubusercontent.com/ros/rosdistro/master/releases/fuerte.yaml 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" Add distro "dashing" Add distro "eloquent" Skip end-of-life distro "groovy" Skip end-of-life distro "hydro" Skip end-of-life distro "indigo" Skip end-of-life distro "jade" Add distro "kinetic" Skip end-of-life distro "lunar" Add distro "melodic" Add distro "noetic" updated cache in /home/XXXX/.ros/rosdep/sources.cache

7：設置環境變量

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc source ~/.bashrc

到這裏ros的安裝已經完成，可是咱們還須要再安裝一些ros依賴的包

8：安裝依賴包

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

至此ROS的安裝已經完成，爲了驗證安裝是否成功，咱們須要測試一下，步驟以下：

9：ros小海龜測試，在終端執行以下命令

roscore
執行成功出現以下信息：
... logging to /home/XXXX/.ros/log/c539a1ea-bcd1-11e9-a4b0-000c29d43c08/roslaunch-ubuntu-30082.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://ubuntu:32889/
ros_comm version 1.14.3


SUMMARY
========

PARAMETERS
 * /rosdistro: melodic
 * /rosversion: 1.14.3

NODES

auto-starting new master
process[master]: started with pid [30092]
ROS_MASTER_URI=http://ubuntu:11311/

setting /run_id to c539a1ea-bcd1-11e9-a4b0-000c29d43c08
process[rosout-1]: started with pid [30103]
started core service [/rosout]

 PS：按Ctr+C可退出終端

此時咱們再另外打開一個終端，而後執行以下命令

rosrun turtlesim turtlesim_node

執行成功出現以下信息：

[ INFO] [1565594556.608022579]: Starting turtlesim with node name /turtlesim [ INFO] [1565594556.613793689]: Spawning turtle [turtle1] at x=[5.544445], y=[5.544445], theta=[0.000000]

此時會出現一個新的窗口，此時的小烏龜是禁止不動的，以下圖

此時咱們再打開一個終端，執行以下代碼：

rosrun turtlesim turtle_teleop_key

執行成功出現以下

Reading from keyboard --------------------------- Use arrow keys to move the turtle.

以上內容的大概意思是咱們能夠用鍵盤控制小烏龜進行移動，咱們在這個終端按鍵盤上的「上、下、左、右」鍵，此時發現小烏龜也在移動，以下圖：

至此，ros在ubuntu 18.04.02上的安裝配置與測試已完成。