jetson xavier nx安装ROS Melodic

打开系统设置-软件和更新 ，确保图示的选项已选中。


点击close，选择reload。
在不同的教程里搜到的这一步都不同，似乎没什么影响，就很迷。。

设置计算机以接受packages.ros.org中的软件。

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

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

sudo apt update

apt search ros-melodic

sudo aptitude install ros-melodic-desktop-full
sudo apt-get install ros-melodic-rqt*

sudo rosdep init

如果报错： sudo: rosdep:command not found
按照以下方式解决：

sudo apt install rospack-tools

之后运行 sudo rosdep init 即可
此时若报错：
ERROR: cannot download default sources list from:
https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/sources.list.d/20-default.list
Website may be down.

多尝试几次，或者更换网络（wifi，热点）
成功后继续执行：

rosdep update

报错：
ERROR: error loading sources list:

解决方法：
定位rosdep资源下载函数。该函数名为download_rosdep_data，位于/usr/lib/python2.7/dist-packages/rosdep2/sources_list.py。我们修改这一函数，添加：
url=“https://ghproxy.com/”+url
修改方法如下：

sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/sources_list.py

回车后，修改对应部分，保存退出。修改后代码如图：

用同样的方法修改/usr/lib/python2.7/dist-packages/rosdistro/init.py里面的DEFAULT_INDEX_URL。
即将DEFAULT_INDEX_URL 进行如下替换：

DEFAULT_INDEX_URL = 'https://ghproxy.com/https://raw.githubusercontent.com/ros/rosdistro/master/index-v4.yaml'

除此处外，下述文件中也含有github地址，分别是：
/usr/lib/python2.7/dist-packages/rosdep2/gbpdistro_support.py 36行
/usr/lib/python2.7/dist-packages/rosdep2/sources_list.py 72行
/usr/lib/python2.7/dist-packages/rosdep2/rep3.py 39行
/usr/lib/python2.7/dist-packages/rosdistro/manifest_provider/github.py 68行83行 119行
将对应网址的最前面加上：https://ghproxy.com/。如将

url = 'https://raw.githubusercontent.com/%s/%s/package.xml' % (path, release_tag)

修改为：

url = 'https://ghproxy.com/https://raw.githubusercontent.com/%s/%s/package.xml' % (path, release_tag)

在/usr/lib/python2.7/dist-packages/rosdep2/gbpdistro_support.py 第204行添加如下代码

gbpdistro_url = ‘https://ghproxy.com/’ + gbpdistro_url

再次尝试执行rosdep update，问题解决。
参考文章：https://blog.csdn.net/leida_wt/article/details/115120940?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522163263712316780265471403%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=163263712316780265471403&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_allfirst_rank_ecpm_v1~rank_v31_ecpm-1-115120940.first_rank_v2_pc_rank_v29&utm_term=%E8%A7%A3%E5%86%B3ROS%E7%B3%BB%E7%BB%9Frosdep+update%E8%B6%85%E6%97%B6%E9%97%AE%E9%A2%98%E7%9A%84&spm=1018.2226.3001.4187

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

运行下述命令。

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

安装完成！

打开一个终端，输入并运行roscore
再打开一个终端，输入并运行rosrun turtlesim turtlesim_node，此时会出现小海龟的界面。
再打开一个终端，输入并运行rosrun turtlesim turtle_teleop_key。保持该终端窗口主语激活状态，按下上下左右方向键，若小海龟可以运动，则说明ros安装成功。

参考文章：
https://blog.csdn.net/qq_41450811/article/details/99079041?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522163262587716780262546694%2522%252C%2522scm%2522%253A%252220140713.130102334…%2522%257D&request_id=163262587716780262546694&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_allsobaiduend~default-2-99079041.first_rank_v2_pc_rank_v29&utm_term=ubuntu18.04+ros+melodic&spm=1018.2226.3001.4187

https://blog.csdn.net/xpy870663266/article/details/94742491?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522163263430716780357285903%2522%252C%2522scm%2522%253A%252220140713.130102334…%2522%257D&request_id=163263430716780357285903&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_allsobaiduend~default-1-94742491.first_rank_v2_pc_rank_v29&utm_term=Unable+to+correct+problems%2C+you+have+held+broken+packages.&spm=1018.2226.3001.4187