ORB_SLAM编译流程及相关报错处理

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写在前面

ORB-SLAM是一种多功能且精确的单目SLAM解决方案，能够在各种环境下实时计算摄像机轨迹和稀疏的3D场景重建，从小型手持序列到在多个城市驾驶的汽车块。它能够关闭大型环路，并实时地从宽基线进行全局重新定位。
注意：本次编译使用的环境是安装在虚拟机中的Ubuntu18.04，且ORB_SLAM是基于ROS运行的，因此请确保已安装好linux环境及ROS系统。

准备工作

1.虚拟机及ROS准备(未使用虚拟机的可跳过此步)

安装虚拟机，并安装好Ubuntu18.04以及ROS系统，详细教程可参见此处
由于是在虚拟机中执行，需要让虚拟机连接到外接USB摄像头或者电脑本机摄像头，详细教程可参见此处

2.ORB_SLAM所需环境准备

首先安装好opencv，网上教程颇多可以自行查阅。
然后使用如下两个命令分别安装boost和eigen3

sudo apt-get install libboost-all-dev
sudo apt-get install libeigen3-dev

详细内容可参考ORB_SLAM提供的README.md文档

3.安装

1.源码下载

访问ORB_SLAM在github上的地址下载源码。
或者在终端执行如下命令：

git clone https://github.com/raulmur/ORB_SLAM.git ORB_SLAM

2.添加环境变量

将克隆ORB_SLAM的路径添加到ROS_PACKAGE_PATH环境变量。为此，请修改.bashrc并在底部添加以下行（替换PATH_TO_PARENT_OF_ORB_SLAM）

export ROS_PACKAGE_PATH=${ROS_PACKAGE_PATH}:PATH_TO_PARENT_OF_ORB_SLAM

例如：如果ORB_SLAM文件夹在主文件夹中则将PATH_TO_PARENT_OF_ORB_SLAM替换为~/ORB_SLAM

3.编译g2o和DBoW2库

分别进入到Thirdparty/g2o/和Thirdparty/DBoW2/目录下执行如下命令：

mkdir build
cd build
cmake … -DCMAKE_BUILD_TYPE=Release
make

4.编译ORB_SLAM

退回到ORB_SLAM/目录下执行如下命令

mkdir build
cd build
cmake … -DCMAKE_BUILD_TYPE=Release
make

编译ORB_SLAM报错处理

1.缺少opencv2

报错如下图所示

解决方法：删除manifest.xml文件中的< depend package=“opencv2”/ > 行，如下图所示

2.缺少头文件

出现类似如下错误：

 In member function ‘void ORB_SLAM::ORBextractor::ComputeKeyPoints(std::vector<std::vectorcv::KeyPoint >&)’:
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:607:63: error: ‘FAST’ was not declared in this scope
FAST(cellImage,cellKeyPoints[i][j],fastTh,true);
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:616:34: error: ‘ORB’ has not been declared
if( scoreType == ORB::HARRIS_SCORE )
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:683:17: error: ‘KeyPointsFilter’ has not been declared
KeyPointsFilter::retainBest(keysCell,nToRetain[i][j]);
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:699:13: error: ‘KeyPointsFilter’ has not been declared
KeyPointsFilter::retainBest(keypoints,nDesiredFeatures);
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc: In member function ‘void ORB_SLAM::ORBextractor::operator()(cv::InputArray, cv::InputArray, std::vectorcv::KeyPoint&, cv::OutputArray)’:
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:760:82: error: ‘GaussianBlur’ was not declared in this scope
GaussianBlur(workingMat, workingMat, Size(7, 7), 2, 2, BORDER_REFLECT_101);
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc: In member function ‘void ORB_SLAM::ORBextractor::ComputePyramid(cv::Mat, cv::Mat)’:
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:800:78: error: ‘INTER_LINEAR’ was not declared in this scope
resize(mvImagePyramid[level-1], mvImagePyramid[level], sz, 0, 0, INTER_LINEAR);
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:800:90: error: ‘resize’ was not declared in this scope
resize(mvImagePyramid[level-1], mvImagePyramid[level], sz, 0, 0, INTER_LINEAR);
^
/home/jy/catkin_ws/src/ORB_SLAM-master/src/ORBextractor.cc:803:80: error: ‘INTER_NEAREST’ was not declared in this scope
resize(mvMaskPyramid[level-1], mvMaskPyramid[level], sz, 0, 0, INTER_NEAREST);
^
make[2]: *** [CMakeFiles/ORB_SLAM-master.dir/src/ORBextractor.cc.o] 错误 1
make[1]: *** [CMakeFiles/ORB_SLAM-master.dir/all] 错误 2
make: *** [all] 错误 2

解决方法：添加缺少的头文件，我的出错是ORBextractor.cc文件，修改如下：

3.Eigen3库的bug

如果出现如下报错：

/usr/local/include/eigen3/Eigen/src/Core/util/StaticAssert.h:32:40: error: static assertion failed: 
YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY
 #define EIGEN_STATIC_ASSERT(X,MSG) static_assert(X,#MSG);

解决方法：打开Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h，将以下代码：

typedef Eigen::PermutationMatrix PermutationMatrix;

替换为：

typedef Eigen::PermutationMatrix PermutationMatrix;

如下图所示：

4.undefined reference to symbol ‘_ZN5boost6system15system_categoryEv’

解决方法：如果出现此错误修改CMakeLists.txt文件如下所示：

写在最后

所有ORB_SLAM编译流程均参考ORB_SLAM提供的README.md文档，如有疑问可以详细阅读此文档，或者评论区指出。
参考文档：

https://github.com/raulmur/ORB_SLAM/blob/master/README.md
https://www.ngui.cc/51cto/show-23557.html
https://blog.csdn.net/weixin_43849277/article/details/109061739
https://www.geek-share.com/detail/2764681691.html
https://blog.csdn.net/danmeng8068/article/details/83827245