Q&A汇总

Q&A汇总

Q：如何解决切换双系统时，时间不一致的问题？

A： 打开Ubuntu系统，打开终端，依次输入： 安装“ntpdate”：

sudo apt-get install ntpdate

连接“time.windows.com”：

sudo ntpdate time.windows.com

然后，再输入下面的命令，更新硬件：

sudo hwclock --localtime --systohc

其他解决方法参考链接：https://blog.csdn.net/weixin_42042056/article/details/104438687

detection模块编译问题（默认安装了Opencv4时）

报错如下：

CMake Error at /opt/ros/melodic/share/cv_bridge/cmake/cv_bridgeConfig.cmake:113 (message):
  Project 'cv_bridge' specifies '/usr/include/opencv' as an include dir,
  which is not found.  It does neither exist as an absolute directory nor in
  '${{prefix}}//usr/include/opencv'.  Check the issue tracker
  'https://github.com/ros-perception/vision_opencv/issues' and consider
  creating a ticket if the problem has not been reported yet.
Call Stack (most recent call first):
  /opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:76 (find_package)
  CMakeLists.txt:51 (find_package)

重新安装opencv3.3.1

• 下载opencv-3.3.1.zip

http://jario.ren/upload/opencv-3.3.1.zip

• 下载opencv_contrib-3.3.1.zip

http://jario.ren/upload/opencv_contrib-3.3.1.zip

将两个zip文件在同一文件夹下解压，然后运行

cd opencv-3.3.1
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=Release -D WITH_CUDA=OFF -D CMAKE_INSTALL_PREFIX=/usr/local -D OPENCV_EXTRA_MODULES_PATH=../../opencv_contrib-3.3.1/modules ..
make -j8
sudo make install

打开ros中的cmake文件

sudo gedit /opt/ros/melodic/share/cv_bridge/cmake/cv_bridgeConfig.cmake

修改96行，/usr/include/opencv->/usr/local/include/opencv

  set(_include_dirs "include;/usr/include;/usr/local/include/opencv")  # line 96

然后重新编译detection模块

cd <path to prometheus>
sudo rm -r build
sudo rm -r devel
./compile_detection.sh