使用USB_CAM跑通ORB-SLAM2

除了正常的编译ORB-SLAM之外，在ROS平台下使用USB_CAM来跑通单目ORB-SLAM，需要执行以下命令

cd ORB_SLAM2/Examples/ROS/ORB_SLAM2

mkdir build

cd build

cmake ..

make 

(1) 在上面的cmake ..命令中会出编译错误

CMake Error at /opt/ros/indigo/share/ros/core/rosbuild/private.cmake::102

[rosbuild] rospack found package "ORB_SLAM2" at " ",but the current directory is "/home/bigh/ORB_SLAM2/Examples/ROS/ORB_SLAM2"，you should double-check your ROS_PACKAGE_PATH to ensure the packages are found in the correct precedence order.

 解决方案：

在.bashrc末尾添加;export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:/home/bigh/ORB_SLAM2/Examples/ROS/ORB_SLAM2

关闭终端重新进行CMake  ..

（2）由于安装了cuda8.0，在make的过程中出现了错误：cannot find -lopencv_dep_cudart

解决方案：

打开要编译的CMakeLists.txt

在find_package(OpenCV 3.0 QUIET)之前添加

set(CUDA_USE_STATIC_CUDA_RUNTIME OFF)

解决了上面的两个问题：打开两个终端分别执行：

（1）切换到usb_cam文件夹下的launch文件夹，执行usb_cam-test.launch

cd catkin_ws/usb_cam/usb_cam/launch

roslaunch usb_cam-test.launch

（2）开启新的终端 执行：

rosrun ORB_SLAM2 Mono /home/bigh/ORB_SLAM2/Vocabulary/ORBvoc.txt /home/bigh/ORB_SLAM2/Examples/Monocular/TUM2.yaml