激光SLAM算法：cartographer

cartographer功能包

cartographer安装

由于cartographer功能包与ROS集成，但没有提供二进制安装包，需要采用源码安装，可参考Cartographer 官网安装教程。

（1）安装工具

In order to build Cartographer ROS, we recommend using wstool and rosdep. For faster builds, we also recommend using Ninja.

$ sudo apt-get update
$ sudo apt-get install -y python-wstool python-rosdep ninja-build

（2）初始化命令空间并安装依赖

Create a new cartographer_ros workspace in ‘catkin_ws’.

$ mkdir catkin_ws
$ cd catkin_ws
$ wstool init src
$ wstool merge -t src https://raw.githubusercontent.com/googlecartographer/cartographer_ros/master/cartographer_ros.rosinstall
$ wstool update -t src

在进行 wstool update -t src 这一步之前，需要替换ceres-solver 源。（Ctrl+h 是否查看隐藏文件）

$ gedit catkin_ws/src/.rosinstall

将https://ceres-solver.googlesource.com/ceres-solver.git
改为https://github.com/ceres-solver/ceres-solver.git

（3）安装proto3以及相关功能包

Install cartographer_ros’ dependencies (proto3 and deb packages). The command ‘sudo rosdep init’ will print an error if you have already executed it since installing ROS. This error can be ignored.

$ src/cartographer/scripts/install_proto3.sh
$ sudo rosdep init
$ rosdep update
$ rosdep install --from-paths src --ignore-src --rosdistro=${ROS_DISTRO} -y

正确安装完成后会出现：#All required rosdeps installed successfully提示。

（4）编译并安装

Build and install.

$ catkin_make_isolated --install --use-ninja
$ source install_isolated/setup.bash

注意：catkin_make_isolated --install --use-ninja一步可能出现虚拟内存耗尽问题。可扩展 swap 交换空间内存解决。

测试

2D SLAM demo

Download the 2D backpack example bag.

$ wget -P ~/Downloads https://storage.googleapis.com/cartographer-public-data/bags/backpack_2d/cartographer_paper_deutsches_museum.bag

Launch the 2D backpack demo.

$ roslaunch cartographer_ros demo_backpack_2d.launch bag_filename:=${HOME}/Downloads/cartographer_paper_deutsches_museum.bag

(图) 2D SLAM demo

map save

$ cd catkin_ws
$ source install_isolated/setup.bash
$ rosservice call /finish_trajectory 0
$ rosservice call /write_state "{filename: '${HOME}/Downloads/mymap.pbstream'}"
$ rosrun cartographer_ros cartographer_pbstream_to_ros_map -map_filestem=${HOME}/Downloads/mymap -pbstream_filename=${HOME}/Downloads/mymap.pbstream -resolution=0.05

(图) 终端显示

(图) 地图保存

3D SLAM demo

Download the 3D backpack example bag.

$ wget -P ~/Downloads https://storage.googleapis.com/cartographer-public-data/bags/backpack_3d/with_intensities/b3-2016-04-05-14-14-00.bag

Launch the 3D backpack demo.

$ roslaunch cartographer_ros demo_backpack_3d.launch bag_filename:=${HOME}/Downloads/b3-2016-04-05-14-14-00.bag

Revo LDS demo

Download the Revo LDS backpack example bag.

$ wget -P ~/Downloads https://storage.googleapis.com/cartographer-public-data/bags/revo_lds/cartographer_paper_revo_lds.bag

Launch the Revo LDS backpack demo.

$ roslaunch cartographer_ros demo_revo_lds.launch bag_filename:=${HOME}/Downloads/cartographer_paper_revo_lds.bag

安装常见问题

安装 protobuf 最新版

$ sudo apt-get install autoconf automake libtool curl make g++ unzip  #安装依赖
$ git clone  https://github.com/google/protobuf  #下载protobuf源码
$ cd protobuf
$ ./autogen.sh
$ ./configure
$ make  #编译
$ make check
$ sudo make install
$ sudo ldconfig   #用于刷新共享库的缓存的 

$ protoc --version  #查看protobuf版本号

扩展 swap 交换空间内存

#下面以增加2G空间为例，count表示增加的块数量（文件大小=bs*count）
$ dd if =/dev/zero of=/root/swapfile bs=1M count=2048
#格式化交换分区文件 
$ sudo mkswap /root/swapfile 
#启用交换分区文件
$ sudo swapon /root/swapfile
#保存以上配置，重启后仍然有效，需要在文件/etc/fstab中添加下面一行
$ /root/swapfile swap swap defaults 0 0