Solutions to ORB_SLAM2 installation and compilation errors

1 Installation tutorial (refer to online course materials for this tutorial)

Install ORB-SLAM2, Pangolin, OpenCV, Eigen, g2o and DBoW2 on the newly installed Ubuntu system (ORB-SLAM2 comes with it)

1.1 Preparation before installation

        Preparation before installation: Install vim, cmake, git, gcc, g++
        sudo apt-get install vim cmake
        sudo apt-get install git
        sudo apt-get install gcc g++

1.2 Install Pangolin (source code installation recommended)

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

1.3 Install OpenCV3.4 (source code installation recommended)

(1) Install dependencies
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) To install OpenCV3.4,
        enter the downloaded installation compressed package, unzip it to a folder, and then go into the folder to create a build folder and compile the folder
        cd opencv-3.4.5
        mkdir build
        cd build
        cmake ..
        make
        sudo make install

(3) Configure environment variables
        sudo vim /etc/ld.so.conf.d/opencv.conf
        Add /usr/local/lib to the opened blank file and
        execute sudo ldconfig to make the configured environment variables take effect

(4) Configure .bashrc, add the following two lines at the end
        //Open .bashrc
        sudo vim /etc/bash.bashrc
        //Add the following two lines to .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) Test whether the installation is normal (if successful, a window with "hello opcv" will appear)
        cd opencv-3.4.5/samples/cpp/example_cmake
        cmake .
        make
        ./opencv_example

1.4 Install Eigen3.3.7 (source code installation recommended)

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

(2) #After installation, the header files are installed in /usr/local/include/eigen3/

(3) #Move the header file
sudo cp -r /usr/local/include/eigen3/Eigen /usr/local/include
Note: #include <Eigen/Dense> is often used when including in many programs instead of #include < eigen3/Eigen/Dense> So we need to do the following processing

1.5 Installing and running ORB-SLAM2 and solutions to common problems

        Install and run ORB_SLAM2 (recommended project directory if under ROS: orbslam_ws/src)
        git clone https://github.com/raulmur/ORB_SLAM2.git ORB_SLAM2
        cd ORB_SLAM2
        chmod +x build.sh
        ./build.sh

2 Installation problems and solutions

Question 1

When installing Pangolin dependencies > sudo apt-get install libpython2.7-dev, there is a problem that the domain name cannot be resolved temporarily.

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”

Solution

Can't access the network. Execute the command to restart the gateway service:

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

Question 2

An error occurred during compilation: '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);
                 ^~~~~~

Solution (1)

usleep problem: directly add #include <unistd.h> to the System.h file in the include folder

In LoopClosing.h will

          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;

Solution(2)

Just add #include <unistd.h> to the corresponding System.cc or other error file paths (as shown below)

        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

Question 3

During installation > error: class 'sigslot::detail::slot_pmf_extended<Pmf, Ptr, Args>' does not have any field named 'ptr' due to version mismatch.

/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

Solution ( reference article )

After careful study of std, I found that some libraries may be called during the compilation process. The libraries use the standard syntax of c++14, but ORB_SLAM2 only has the syntax permission of c++11 and not 14. This caused conflict.

(1) Open ORB_SLAM3/CMakeLists.txt
(2) Add c++14 license > add_compile_options(-std=c++14)

Question 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.

Solution (1)

It may be caused by Pangolin not supporting it. Reinstall Pangolin and uninstall it before reinstalling.

(1) Delete libraries and header files

        cd Pangolin/build
        make clean
        sudo make uninstall

After execution, all .so files and .h files will begin to be uninstalled.

(2) Delete source code

cd ../..
sudo rm -r Pangolin

Delete the source code folder after execution.

(3) Delete residual folders

Update the index and search for the location of pangolin

sudo updatedb
locate pangolin

You can see that the /usr/local/include/pangolin directory has not been deleted, because the first step is to uninstall all .h files in this directory.

        /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

Therefore, we can delete this directory.

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

(4) Check for uninstallation

Search the location of pangolin again

locate pangolin

I found that it can only be found in Trash, and the uninstallation was successful!

        /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) Reinstall the Pangolin library (above)

Solution(2)

Changing find_package(Eigen3 3.1.0 REQUIRED) to find_package(Eigen3 3.1.0 REQUIRED NO_MODULE) in cmakelist .txt solved the problem.

Question 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

Solution ( reference article )

The problem occurs because there are differences between C++ versions. Momotonic_clock is no longer available in C++11, and is replaced by steady_clock. So the author of orb-slam2 used ifdef in the code to determine the user's C++ version. The code segment that needs to be processed for the files under the corresponding path is as follows.

#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

If you report an error in this part, there is a high probability that your C++ is version 11, then we can actually delete this part of the judgment statement and only keep the following part.

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();

//......

This part is enough. After deleting the monotonic_clock code, it will compile normally!

Question 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

Solution ( reference article )

The Eigen library is different from ordinary libraries. It only has header files and does not have binary library files like .so and .a. Where does libEigen.so come from? You need -l?

Added in CMakeLists.txt

#Add the red statement
find_package(Eigen3 3.3 REQUIRED NO_MODULE )

#When compiling an error, add the following statement
include(FindEigen3.cmake)