树莓派|树莓派4BUbuntu18.04安装ROS Melodic完整教程及部分报错解决方法树莓派|Linux

树莓派4BUbuntu18.04安装ROS Melodic完整教程及部分报错解决方法请连接信号较好速度较快的wifi，或者使用手机wifi，否则将导致安装失败。
部分教程参考（https://blog.csdn.net/qq_41450811/article/details/99079041）
安装过程中遇到问题请转到文末。

1：设置软件源

sudo gedit /etc/apt/sources.list

将文档里面的内容替换成

deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic main multiverse restricted universe deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-backports main multiverse restricted universe deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-proposed main multiverse restricted universe deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security main multiverse restricted universe deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates main multiverse restricted universe deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic main multiverse restricted universe deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-backports main multiverse restricted universe deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-proposed main multiverse restricted universe deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security main multiverse restricted universe deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates main multiverse restricted universe## Note, this file is written by cloud-init on first boot of an instance ## modifications made here will not survive a re-bundle. ## if you wish to make changes you can: ## a.) add 'apt_preserve_sources_list: true' to /etc/cloud/cloud.cfg ##or do the same in user-data ## b.) add sources in /etc/apt/sources.list.d ## c.) make changes to template file /etc/cloud/templates/sources.list.tmpl# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://ports.ubuntu.com/ubuntu-ports bionic main restricted # deb-src http://ports.ubuntu.com/ubuntu-ports bionic main restricted## Major bug fix updates produced after the final release of the ## distribution. deb http://ports.ubuntu.com/ubuntu-ports bionic-updates main restricted # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-updates main restricted## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://ports.ubuntu.com/ubuntu-ports bionic universe # deb-src http://ports.ubuntu.com/ubuntu-ports bionic universe deb http://ports.ubuntu.com/ubuntu-ports bionic-updates universe # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-updates universe## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://ports.ubuntu.com/ubuntu-ports bionic multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports bionic multiverse deb http://ports.ubuntu.com/ubuntu-ports bionic-updates multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-updates multiverse## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://ports.ubuntu.com/ubuntu-ports bionic-backports main restricted universe multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-backports main restricted universe multiverse## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu bionic partner # deb-src http://archive.canonical.com/ubuntu bionic partnerdeb http://ports.ubuntu.com/ubuntu-ports bionic-security main restricted # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-security main restricted deb http://ports.ubuntu.com/ubuntu-ports bionic-security universe # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-security universe deb http://ports.ubuntu.com/ubuntu-ports bionic-security multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports bionic-security multiverse deb http://ports.ubuntu.com/ubuntu-ports bionic-proposed restricted main multiverse universe

换成国内的源，下载速度会快一些，ctrl+s保存，打开Software&Update，软件源替换成如图所示。

树莓派|树莓派4BUbuntu18.04安装ROS Melodic完整教程及部分报错解决方法

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打开终端输入以下命令：

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list' 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' sudo sh -c '. /etc/lsb-release && echo "deb http://mirrors.tuna.tsinghua.edu.cn/ros/ubuntu/ $DISTRIB_CODENAME main" > /etc/apt/sources.list.d/ros-latest.list'

2 设置最新的密钥

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

执行效果：

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3 安装

sudo apt-get update

执行效果

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

执行效果：

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4初始化rosdep:

sudo rosdep init rosdep update

执行效果

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5安装rosinstall:

sudo apt-get install python-rosinstall

6 加载环境设置文件

source /opt/ros/melodic/setup.bash

7 创建并初始化工作目录
ROS使用一个名为catkin的ROS专用构建系统。为了使用它，用户需要创建并初始化catkin工作目录，如下所示。除非用户创建新的工作目录，否则此设置只需设置一次。

mkdir -p ~/catkin_ws/src cd ~/catkin_ws/src catkin_init_workspace

目前，只有src目录和CMakeLists.txt文件在catkin工作目录中，使用catkin_make命令来构建

cd ~/catkin_ws/ catkin_make

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8设置环境变量：

sudo apt install net-tools gedit ~/.bashrc

在最后一行添加以下内容，其中ROS_HOSTNAME需要换成本机ip地址，一般可以设置为localhost

# Set ROS melodic source /opt/ros/melodic/setup.bash source ~/catkin_ws/devel/setup.bash # Set ROS Network #ifconfig查看你的电脑ip地址或者使用localhost代替 export ROS_HOSTNAME=localhost export ROS_MASTER_URI=http://${ROS_HOSTNAME}:11311

9：验证安装

rosversion –d

执行效果：

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10小海龟测试，打开三个终端：

roscore rosrun turtlesim turtlesim_node rosrun turtlesim turtle_teleop_key

执行效果：

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安装过程中可能出现的问题及其解决办法： 1：如果出现错误： Could not get lock /var/lib/dpkg/lock - open解决方法
主要原因：主要是因为apt还在运行
解决方案：杀死所有的apt进程。
(1)查找所有apt相关的进程，并用命令杀死。例如

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(2) 锁定的文件会阻止 Linux 系统中某些文件或者数据的访问，这个概念也存在于 Windows 或者其他的操作系统中。
一旦你运行了 apt-get 或者 apt 命令，锁定文件将会创建于 /var/lib/apt/lists/、/var/lib/dpkg/、/var/cache/apt/archives/ 中。
这有助于运行中的 apt-get 或者 apt 进程能够避免被其它需要使用相同文件的用户或者系统进程所打断。当该进程执行完毕后，锁定文件将会删除。
所以：
①移除对应目录下的锁文件：
②强制重新配置软件包：
③更新软件包源文件：

$ sudo rm /var/lib/dpkg/lock 之后像下面这样强制重新配置软件包： $ sudo dpkg --configure –a 接下来，更新你的软件包源列表： $ sudo apt update

2：sudo rosdep init时出现问题：

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.

主要原因：网络问题
解决办法：(1)换个网络尝试下（可以尝试手机热点）;
(2)如果不行的话