Setup ORB with Web Cam

Requirements

1. Ubuntu 18.04

2. C++ 7.5

3. Opencv 3.2.0

4. ROS Melodic (other version is possible)

Project Directory Structure

orb_slam
 └ src
    └ ORB_SLAM3
    └ Pangolin
    └ opencv
 └ build (ROS)

Setup

mkdir orb_slam
cd orb_slam

1. ROS Install

following the instruction melodic/Installation/Ubuntu - ROS Wiki:

1. Configure Ubuntu Repositories

   sudo add-apt-repository restricted
   sudo add-apt-repository universe
   sudo add-apt-repository multiverse
   

2. Setup sources.list and keys

   sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
   sudo apt install curl 
   curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
   

3. Installation

   sudo apt update
   sudo apt-get install ros-melodic-desktop-full
   

4. Environment setup

   echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
   source ~/.bashrc
   

5. Dependencied

   sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential
   

2. ORB-Dependency Install

ORB_SLAM3

1. GCC

   GCC 7.5 is the default version in Ubuntu 18.04. If not, please try to install 7.5 and set it to default.

2. Download Repos

   mkdir src
   cd src
   
   git clone https://github.com/UZ-SLAMLab/ORB_SLAM3.git
   git clone https://github.com/stevenlovegrove/Pangolin
   git clone https://github.com/opencv/opencv.git
   

3. OpenCV

   cd opencv
   git checkout 3.2.0
   

   sed -i '42s/^/#define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)\n#define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER\n#define AVFMT_RAWPICTURE 0x00\n/' ./modules/videoio/src/cap_ffmpeg_impl.hpp
   

   mkdir build
   cd build
   cmake -D ENABLE_PRECOMPILED_HEADERS=OFF -D CMAKE_BUILD_TYPE=Release -D WITH_CUDA=OFF -D CMAKE_INSTALL_PREFIX=/usr/local ..
   make -j 4   # -j [N] : Allow N jobs at once
   sudo make install
   

4. Pangolin

   cd ../../Pangolin
   mkdir build 
   cd build 
   cmake -D CMAKE_BUILD_TYPE=Release ..
   make -j 4
   sudo make install
   
   
   # if GLEW not found by cmake
   sudo apt install libglew-dev
   

3. ROS setting

1. Build Thirdparty

   cd Thirdparty/
   
   cd DBoW2/
   mkdir build
   cd build
   cmake -DCMAKE_BUILD_TYPE=Release ..
   make
   
   cd ../../g2o/
   mkdir build
   cd build
   cmake -DCMAKE_BUILD_TYPE=Release ..
   make
   
   cd ../../Sophus/
   mkdir build
   cd build
   cmake -DCMAKE_BUILD_TYPE=Release ..
   make
   

2. ROS setting instruction

   cd ../../ORB_SLAM3
   mv Examples_old/ROS/ Examples/
   
   sed -i 's+/camera/image_raw+/usb_cam/image_raw+g' ./Examples/ROS/ORB_SLAM3/src/ros_mono.cc
   
   sudo apt install ros-melodic-usb-cam
    
   sudo rosdep init
   rosdep update
   
   echo "export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:~/orb_slam/src/ORB_SLAM3/Examples/ROS/" >> ~/.bashrc
   source ~/.bashrc
   sed -i '46s+^+${PROJECT_SOURCE_DIR}/../../../Thirdparty/Sophus\n+' ./Examples/ROS/ORB_SLAM3/CMakeLists.txt
   
   sed -i 's+cv::Mat Xw = pMP->GetWorldPos();+cv::Mat Xw;\ncv::eigen2cv(pMP->GetWorldPos(), Xw);+g' ./Examples/ROS/ORB_SLAM3/src/AR/ViewerAR.cc
   sed -i 's+vPoints.push_back(pMP->GetWorldPos());+cv::Mat WorldPos;\ncv::eigen2cv(pMP->GetWorldPos(), WorldPos);\nvPoints.push_back(WorldPos);+g' ./Examples/ROS/ORB_SLAM3/src/AR/ViewerAR.cc
   sed -i '27s+^+#include <Eigen/Dense>\n#include <opencv2/core/eigen.hpp>\n#include <opencv2/opencv.hpp>\n+' ./Examples/ROS/ORB_SLAM3/src/AR/ViewerAR.cc
   sed -i '27s+^+#include <Eigen/Dense>\n#include <opencv2/core/eigen.hpp>\n#include <opencv2/opencv.hpp>\n+' ./Examples/ROS/ORB_SLAM3/src/AR/ros_mono_ar.cc
   sed -i 's+cv::Mat Tcw = mpSLAM->TrackMonocular(cv_ptr->image,cv_ptr->header.stamp.toSec());+cv::Mat Tcw;\nSophus::SE3f Tcw_SE3f = mpSLAM->TrackMonocular(cv_ptr->image,cv_ptr->header.stamp.toSec());\nEigen::Matrix4f Tcw_Matrix = Tcw_SE3f.matrix();\ncv::eigen2cv(Tcw_Matrix, Tcw);\n+g' ./Examples/ROS/ORB_SLAM3/src/AR/ros_mono_ar.cc
   

3. build

   #first build normal verison to get libORB_SLAM3.so
   sed -i 's+OpenCV 4.4+OpenCV 3.2+g' CMakeLists.txt
   ./build.sh
   

   ./build_ros.sh
   

4. run

   # Terminal 1
   roscore
   
   
   # Terminal 2
   roslaunch usb_cam usb_cam-test.launch 
   
   
   # Terminal 3
   rosrun ORB_SLAM3 Mono Vocabulary/ORBvoc.txt Examples/Monocular/EuRoC.yaml