新建工程
# 创建catkin工程环境，如果已有则跳过
# mkdir -p catkin_ws/src
cd src
catkin_create_pkg showpath roscpp sensor_msgs std_msgs nav_msgs tf
cd ..
catkin_make
【catkin_make时报错：No module named 'catkin_pkg'】
ImportError: “from catkin_pkg.topological_order import topological_order” failed: No module named 'catkin_pkg'
Make sure that you have installed “catkin_pkg”, it is up to date and on the PYTHONPATH.
解决方案：
- 打开catkin_make文件
sudo gedit /opt/ros/kinetic/bin/catkin_make
由于catkin_make为系统文件readonly，因此不可以通过vim编辑 2.将python脚本解释器改为
#!/usr/bin/python2即可
编译和运行
- 编写主函数：在
showpath/src/中创建showpath.cpp - 编辑
CMakeLists.txt: 在showpath/CMakeLists.txt最后增加两行
add_executable(showpath src/showpath.cpp)
target_link_libraries(showpath ${catkin_LIBRARIES})
- 编译
# 回到catkin_ws目录
# cd ~/catkin_ws
rm -rf build
catkin_make -j2
- 运行
source ./devel/setup.bash
# 打开一个终端运行
roscore
# 打开另一个终端运行
rosrun showpath showpath
# 打开第三个终端测试
rostopic echo /trajector
【rosrun时报错：无法连接到ROS master，ERROR: unable to contact ROS master at [http://192.168.0.20:11311]】
问题原因：没有运行roscore
解决方案：在新终端运行roscore
其他解决办法：导出路径
$ export ROS_HOSTNAME=localhost
$ export ROS_MASTER_URI=http://localhost:11311
【报错：libroscpp.so: cannot open shared object file: No such file or directory】
[rosout-1] restarting process
/opt/ros/melodic/lib/rosout/rosout: error while loading shared libraries: libroscpp.so: cannot open shared object file: No such file or directory
process[rosout-1]: started with pid [14028]
[rosout-1] process has died [pid 14028, exit code 127, cmd /opt/ros/melodic/lib/rosout/rosout __name:=rosout __log:=/home/nano/.ros/log/9bbbb974-69d3-11eb-a0bf-48b02d2de5df/rosout-1.log].
log file: /home/nano/.ros/log/9bbbb974-69d3-11eb-a0bf-48b02d2de5df/rosout-1*.log
解决方案： 在命令行中直接输入一下指令指定路径
LD_LIBRARY_PATH=/opt/ros/melodic/lib
rviz实验效果
rosrun rviz rviz
- 在
Global Options中把第一项Fixed Frame改为world - 点击侧边栏左下角的
Add，添加一个Path - 在
Path中下拉Topic，选择/trajectory
Resources
一些原理和nav_msgs/Path.msg结构等可以参考：ROS在rviz中实时显示轨迹（nav_msgs/Path消息的使用）_qq_43176116的博客-CSDN博客
