ORB_SLAM2安装与编译报错的解决办法

        安装前的准备：安装 vim 、 cmake 、 git 、 gcc 、 g++
        sudo apt-get install vim cmake
        sudo apt-get install git
        sudo apt-get install gcc g++

1.2 安装Pangolin (建议源码安装)

（1）安装依赖项
        sudo apt-get install libglew-dev
        sudo apt-get install libboost-dev libboost-thread-dev libboost-filesystem-dev
        sudo apt-get install libpython2.7-dev

（2）安装 Pangolin
        git clone https://github.com/stevenlovegrove/Pangolin.git
        cd Pangolin
        mkdir build
        cd build
        cmake -DCPP11_NO_BOOSR=1 ..
        make -j

1.3 安装OpenCV3.4 (建议源码安装 )

（1）安装依赖项
sudo apt-get install build-essential libgtk2.0-dev libavcodec-dev libavformat-dev libjpeg.dev
sudo apt-get install libtiff4.dev libswscale-dev libjasper-dev

（2）安装 OpenCV3.4
        进入下载的安装压缩包，解压到某文件夹，然后进去该文件夹建立build文件夹编译文件夹
        cd opencv-3.4.5
        mkdir build
        cd build
        cmake ..
        make
        sudo make install

（3）配置环境变量
        sudo vim /etc/ld.so.conf.d/opencv.conf
        在打开的空白文件中添加 /usr/local/lib
        执行 sudo ldconfig ,使配置的环境变量生效

（4）配置 .bashrc ，末尾添加下面两行
        //打开.bashrc
        sudo vim /etc/bash.bashrc
        //添加以下两行内容到.bashrc
        PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
        export PKG_CONFIG_PATH

（5）source 与 update
source /etc/bash.bashrc
sudo updatedb

（6）测试是否正常安装 (成功会出现带 “hello opcv” 字样的窗口)
        cd opencv-3.4.5/samples/cpp/example_cmake
        cmake .
        make
        ./opencv_example

1.4 安装Eigen3.3.7 (建议源码安装)

（1）安装
        cd eigen-git-mirror
        mkdir build
        cd build
        cmake ..
        sudo make install

（2）#安装后头文件安装在/usr/local/include/eigen3/

（3）#移动头文件
sudo cp -r /usr/local/include/eigen3/Eigen /usr/local/include
备注：在很多程序中 include 时经常使用 #include <Eigen/Dense> 而不是使用 #include <eigen3/Eigen/Dense> 所以要做下处理

1.5 安装运行ORB-SLAM2及常见问题解决办法

        安装运行ORB_SLAM2 (如果在ROS下推荐工程目录: orbslam_ws/src )
        git clone https://github.com/raulmur/ORB_SLAM2.git ORB_SLAM2
        cd ORB_SLAM2
        chmod +x build.sh
        ./build.sh

2 安装问题及解决办法

问题1

安装Pangolin 依赖项 > sudo apt-get install libpython2.7-dev时出现暂时不能解析域名问题。

错误:1 http://security.ubuntu.com/ubuntu focal-updates/universe amd64 libpython2.7-minimal amd64 2.7.18-1~20.04.3
  暂时不能解析域名“cn.archive.ubuntu.com”
错误:2 http://security.ubuntu.com/ubuntu focal-updates/universe amd64 libpython2.7-stdlib amd64 2.7.18-1~20.04.3
  暂时不能解析域名“cn.archive.ubuntu.com”

解决办法

访问不了网络。执行命令，重启网关服务：

sudo service network-manager stop //把network-manager停掉（//后的不要复制）
sudo rm /var/lib/NetworkManager/NetworkManager.state
sudo service network-manager start  //启动

问题2

编译时出现了error: ‘usleep’ was not declared in this scope usleep(1000);
^~~~~~

/home/hazyparker/project/ORB_SLAM2/src/System.cc: In member function ‘cv::Mat ORB_SLAM2::System::TrackStereo(const cv::Mat&, const cv::Mat&, const double&)’:
/home/hazyparker/project/ORB_SLAM2/src/System.cc:134:17: error: ‘usleep’ was not declared in this scope
                 usleep(1000);
                 ^~~~~~
/home/hazyparker/project/ORB_SLAM2/src/System.cc:134:17: note: suggested alternative: ‘fseek’
                 usleep(1000);
                 ^~~~~~
                 fseek
/home/hazyparker/project/ORB_SLAM2/src/System.cc: In member function ‘cv::Mat ORB_SLAM2::System::TrackRGBD(const cv::Mat&, const cv::Mat&, const double&)’:
/home/hazyparker/project/ORB_SLAM2/src/System.cc:185:17: error: ‘usleep’ was not declared in this scope
                 usleep(1000);
                 ^~~~~~

解决办法（1）

usleep问题：直接在include文件夹下 System.h 文件中加上#include <unistd.h>

在LoopClosing.h中将

          typedef map<KeyFrame*,g2o::Sim3,std::less<KeyFrame*>,
          Eigen::aligned_allocator<std::pair<const KeyFrame*, g2o::Sim3> > > KeyFrameAndPose;
        改为

typedef map<KeyFrame*,g2o::Sim3,std::less<KeyFrame*>,
Eigen::aligned_allocator<std::pair<KeyFrame *const, g2o::Sim3> > > KeyFrameAndPose;

解决办法（2）

只需要在对应的System.cc或其他报错的文件路径中（如下）添加#include <unistd.h>

        ORB_SLAM2/src/LocalMapping.cc
        ORB_SLAM2/src/LoopClosing.cc
        ORB_SLAM2/src/System.cc
        ORB_SLAM2/src/Tracking.cc
        ORB_SLAM2/src/Viewer.cc
        ORB_SLAM2/Examples/Monocular/mono_euroc.cc
        ORB_SLAM2/Examples/Monocular/mono_kitti.cc
        ORB_SLAM2/Examples/Monocular/mono_tum.cc
        ORB_SLAM2/Examples/RGB-D/rgbd_tum.cc
        ORB_SLAM2/Examples/Stereo/stereo_euroc.cc
        ORB_SLAM2/Examples/Stereo/stereo_kitti.cc

问题3

安装时可能出现 > error: class ‘sigslot::detail::slot_pmf_extended<Pmf, Ptr, Args>’ does not have any field named ‘ptr’ 由于版本不匹配的问题。

/usr/local/include/sigslot/signal.hpp:958:11: error: class ‘sigslot::detail::slot_pmf_extended<Pmf, Ptr, Args>’ does not have any field named ‘pmf’
  958 |         , pmf{std::forward<F>(f)}
      |           ^~~
/usr/local/include/sigslot/signal.hpp:959:11: error: class ‘sigslot::detail::slot_pmf_extended<Pmf, Ptr, Args>’ does not have any field named ‘ptr’
  959 |         , ptr{std::forward<P>(p)} {}
      |           ^~~
/usr/local/include/sigslot/signal.hpp:1376:10: error: ‘enable_if_t’ in namespace ‘std’ does not name a template type; did you mean ‘enable_if’?
 1376 |     std::enable_if_t<(trait::is_callable_v<arg_list, Callable> ||
      |          ^~~~~~~~~~~
      |          enable_if
/usr/local/include/sigslot/signal.hpp:1399:10: error: ‘enable_if_t’ in namespace ‘std’ does not name a template type; did you mean ‘enable_if’?
 1399 |     std::enable_if_t<!trait::is_callable_v<arg_list, Obj> &&
      |          ^~~~~~~~~~~
      |          enable_if
/usr/local/include/sigslot/signal.hpp: In member function ‘const std::type_info& sigslot::detail::slot_tracked<Func, WeakPtr, Args>::get_callable_type() const’:
/usr/local/include/sigslot/signal.hpp:1027:23: error: ‘func’ was not declared in this scope; did you mean ‘Func’?
 1027 |         return typeid(func);
      |                       ^~~~
      |                       Func

解决办法（参考文章）

仔细研究std后发现，可能是编译过程中调用了某一些库，库里面使用的是c++14的标准语法，但ORB_SLAM2中只有c++11的语法许可，没有14的，这就造成了冲突。

（1）打开ORB_SLAM3/CMakeLists.txt
（2）添加c++14的使用许可 > add_compile_options(-std=c++14)

问题4

  but it set Pangolin_FOUND to FALSE so package "Pangolin" is considered to
  be NOT FOUND.  Reason given by package:

  Pangolin could not be found because dependency Eigen3 could not be found.

解决办法（1）

可能由于Pangolin不对应造成，重新安装Pangolin，重新安装前先卸载。

（1）删除库和头文件

        cd Pangolin/build
        make clean
        sudo make uninstall

执行之后就会开始卸载所有的.so文件和.h文件。

（2）删除源代码

cd ../..
sudo rm -r Pangolin

执行之后删除源代码文件夹。

（3）删除残留文件夹

更新下索引，搜索pangolin的位置

sudo updatedb
locate pangolin

可以看到在/usr/local/include/pangolin目录还未删除，因为第一步是卸载了该目录下的所有.h文件。

        /usr/local/include/pangolin
        /usr/local/include/pangolin/compat
        /usr/local/include/pangolin/console
        /usr/local/include/pangolin/display
        /usr/local/include/pangolin/factory
        /usr/local/include/pangolin/geometry
        /usr/local/include/pangolin/gl
        /usr/local/include/pangolin/handler
        /usr/local/include/pangolin/image
        /usr/local/include/pangolin/log

所以，我们将该目录删除即可。

sudo rm -r /usr/local/include/pangolin

（4）检查卸载

再次搜索pangolin的位置

locate pangolin

发现只有在Trash中才能找到，卸载成功！

        /home/dzh/.local/share/Trash/expunged/2600043745/build/include/pangolin
        /home/dzh/.local/share/Trash/expunged/2600043745/build/include/pangolin/factory
        /home/dzh/.local/share/Trash/expunged/2600043745/build/include/pangolin/factory/RegisterFactoriesVideoInterface.h
        /home/dzh/.local/share/Trash/expunged/2600043745/build/include/pangolin/factory/RegisterFactoriesVideoOutputInterface.h
        /home/dzh/.local/share/Trash/expunged/2600043745/build/include/pangolin/factory/RegisterFactoriesWindowInterface.h

（5）重新安装Pangolin库（上文）

解决办法（2）

在cmakelist .txt中将find_package(Eigen3 3.1.0 REQUIRED)更改为find_package(Eigen3 3.1.0 REQUIRED NO_MODULE)解决了这个问题。

问题5

/home/qinlong/Software/ORB_SLAM2/Examples/Monocular/mono_tum.cc:82:22: error: ‘std::chrono::monotonic_clock’ has not been declared
   82 |         std::chrono::monotonic_clock::time_point t1 = std::chrono::monotonic_clock::now();
      |                      ^~~~~~~~~~~~~~~
/home/qinlong/Software/ORB_SLAM2/Examples/Monocular/mono_tum.cc:91:22: error: ‘std::chrono::monotonic_clock’ has not been declared
   91 |         std::chrono::monotonic_clock::time_point t2 = std::chrono::monotonic_clock::now();
      |                      ^~~~~~~~~~~~~~~
/home/qinlong/Software/ORB_SLAM2/Examples/Monocular/mono_tum.cc:94:83: error: ‘t2’ was not declared in this scope; did you mean ‘tm’?
   94 |         double ttrack= std::chrono::duration_cast<std::chrono::duration<double> >(t2 - t1).count();
      |                                                                                   ^~
      |                                                                                   tm
/home/qinlong/Software/ORB_SLAM2/Examples/Monocular/mono_tum.cc:94:88: error: ‘t1’ was not declared in this scope; did you mean ‘y1’?
   94 |         double ttrack= std::chrono::duration_cast<std::chrono::duration<double> >(t2 - t1).count();
      |                                                                                        ^~
      |                                                                                        y1

解决办法（参考文章）

出现这个问题的原因是C++版本之间存在区别。在C++11版里已经没有momotonic_clock了，有steady_clock作为替代。所以orb-slam2的作者在代码中使用了ifdef来判断用户的C++版本。对应路径下的文件需处理的代码段如下。

#ifdef COMPILEDWITHC11
        std::chrono::steady_clock::time_point t1 = std::chrono::steady_clock::now();
#else
        std::chrono::monotonic_clock::time_point t1 = std::chrono::monotonic_clock::now();
#endif

        //Pass the image to the SLAM system
        SLAM.TrackMonocular(im,tframe);

#ifdef COMPILEDWITHC11
        std::chrono::steady_clock::time_point t2 = std::chrono::steady_clock::now();
#else
        std::chrono::monotonic_clock::time_point t2 = std::chrono::monotonic_clock::now();
#endif

如果你这部分报错了，大概率你的C++是11版本，那么我们其实可以删掉这部分判断语句，只保留如下部分。

std::chrono::steady_clock::time_point t1 = std::chrono::steady_clock::now();

 //Pass the image to the SLAM system
 SLAM.TrackMonocular(im,tframe);

std::chrono::steady_clock::time_point t2 = std::chrono::steady_clock::now();

//......

这部分就行，把monotonic_clock的代码删掉之后就能正常编译了！

问题6：

/usr/bin/ld: cannot find -lEigen3::Eigen
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/joinMap.dir/build.make:102: joinMap] Error 1
make[1]: *** [CMakeFiles/Makefile2:76: CMakeFiles/joinMap.dir/all] Error 2
make: *** [Makefile:84: all] Error 2

解决办法（参考文章）

Eigen库不同于一般的库，它只有头文件，没有.so和 .a那样的二进制库文件哪来的libEigen.so需要你-l ?

CMakeLists.txt中添加

#添加红色语句
find_package(Eigen3 3.3 REQUIRED NO_MODULE)

#编译报错再添加如下语句
include(FindEigen3.cmake)