20.04搭建ROS2

1)修改源文件source.list为阿里云

deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse

2)卸载全部ros:

sudo apt-get autoremove --purge ros-*

3)设置编码

sudo locale-gen en_US en_US.UTF-8
sudo update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
export LANG=en_US.UTF-8

4)添加key

sudo apt update && sudo apt install curl gnupg2 lsb-release

WINDOWS下打开并下载https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc
把文件另存为ros.asc文件，然后用U盘传到ubuntu系统，然后在文件录下运行命令行：

sudo apt-key add ros.asc

5)添加ros源

sudo sh -c 'echo "deb [arch=$(dpkg --print-architecture)] http://mirror.tuna.tsinghua.edu.cn/ros2/ubuntu $(lsb_release -cs) main" > /etc/apt/sources.list.d/ros2-latest.list'

 6)删除sources.list.d其他的源

7)安装ros

sudo apt update
sudo apt install ros-foxy-desktop

8)加载ros2

source /opt/ros/foxy/setup.bash

9) 自动补全

sudo apt install python3-argcomplete

 10)安装开发工具和ros工具

sudo apt update && sudo apt install -y \
  build-essential \
  cmake \
  git \
  python3-colcon-common-extensions \
  python3-pip \
  python3-rosdep \
  python3-vcstool \
  wget

python3 -m pip install -U \
argcomplete \
flake8-blind-except \
flake8-builtins \
flake8-class-newline \
flake8-comprehensions \
flake8-deprecated \
flake8-docstrings \
flake8-import-order \
flake8-quotes \
pytest-repeat \
pytest-rerunfailures \
pytest

sudo apt install --no-install-recommends -y \
libasio-dev \
libtinyxml2-dev

sudo apt install --no-install-recommends -y \
libcunit1-dev

11)加入到bashrc: 

echo “source /opt/ros/foxy/setup.bash” >> ~/.bashrc

12）测试验证

新开终端，发布话题

source /opt/ros/foxy/setup.bash
ros2 run demo_nodes_cpp talker

新开终端，订阅话题

source /opt/ros/foxy/setup.bash
ros2 run demo_nodes_py listener

坑1RMW问题需要添加环境变量

export RMW_IMPLEMENTATION=rmw_connext_cpp

 坑2注意用户下的.bash文件