利用下面文章建立RPLidar的ROS環境

Getting Started with the Low-Cost RPLIDAR Using Jetson Nano

 安裝過程遇到下列錯誤訊息，解決方法如下

rosdep: command not found

> sudo apt-get install python-pip
> sudo pip install -U rosdep
> sudo rosdep init
> rosdep update

安裝成功，每次重開機需做下列步驟:

先接上rplidar硬體，然後確認是否有讀寫權限

> ls -al /dev | grep ttyUSB

crw-rw---- 1 root dialout 188, 0 3月 12 19:27 ttyUSB0

修改讀寫權限

> sudo chmod 666 /dev/ttyUSB0

crw-rw-rw- 1 root dialout 188, 0 3月 12 19:27 ttyUSB0

> roscore

-------------------------------------------------------------------------------

開啟另一個terminal視窗

> cd catkin_ws

>  source devel/setup.bash

> roslaunch rplidar_ros view_rplidar.launch

進階應用Simutaneous Localization and Mapping

利用下面兩支影片建立SLAM範例

RPLidar and Hector SLAM for Beginners | ROS Tutorial #8

ROS SLAM #2 Hector SLAM (2D地圖建置)

[下載Hector SLAM]

> git clone https://github.com/tu-darmstadt-ros-pkg/hector_slam

$ cd ~/catkin_ws/src

$ git clone https://github.com/tu-darmstadt-ros-pkg/hector_slam

$ cd ~/catkin_ws

$ catkin_make

 

安裝過程遇到錯誤，原因是預設OpenCV路徑不正確所導致

cv_bridge‘ specifies ‘/usr/include/opencv‘ as an include dir, which is not found

開啟並編輯

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

搜尋下面關鍵字

​​/usr/include/opencv/

並替換成電腦opencv安裝路徑

​​/usr/include/opencv4/opencv2​

繼續

>  catkin_make 

---------------------------------------------------------------------------------

hector_slam安裝成功，每次重開機需做下列步驟:

先接上rplidar硬體，然後確認是否有讀寫權限

> ls -al /dev | grep ttyUSB

crw-rw---- 1 root dialout 188, 0 3月 12 19:27 ttyUSB0

修改讀寫權限

> sudo chmod 666 /dev/ttyUSB0

terminal window #1

> cd ~/catkin_ws

> source devel/setup.bash

>  roslaunch rplidar_ros rplidar.launch

terminal window #2

> cd ~/catkin_ws

> source devel/setup.bash

> roslaunch hector_slam_launch tutorial.launch

Open another terminal

> cd ~/catkin_ws

> rostopic list

/clicked_point
/initialpose
/map
/map_metadata
/map_updates
/move_base_simple/goal
/poseupdate
/rosout
/rosout_agg
/scan
/slam_cloud
/slam_out_pose
/syscommand
/tf
/tf_static
/trajectory

> rostopic echo /tf

transforms:
-
header:
seq: 0
stamp:
secs: 1678740940
nsecs: 988864325
frame_id: "map"
child_frame_id: "scanmatcher_frame"
transform:
translation:
x: -0.00157928466797
y: 0.00636672973633
z: 0.0
rotation:
x: 0.0
y: 0.0
z: -0.0231230224836
w: 0.999732627171
---

Making a Mobile Robot #8 - Adding a Lidar

Ubuntu install of ROS Noetic

ROS Lesson 01 - Install ROS Noetic on Ubuntu 20.04