cd ~/{workspace}/src
git clone --recursive https://github.com/leggedrobotics/darknet_ros.git
cd ..
catkin_make -DCMAKE_BUILD_TYPE=Release
rospack profile
git clone --recursive는 서브모듈까지 클론해줌
&python3
>>> import rospy
>>> import cv_bridge
not error ok
roscore
roslaunch usb_cam usb_cam-test.launch
roslaunch darknet_ros darknet_ros.launch