用Python實現ROS節點(編寫簡單的訊息釋出器和訂閱器)
阿新 • • 發佈：2019-02-14
編寫一個簡單的釋出器和訂閱器
1.建立工作空間
建立資料夾hello_rospy,再在該目錄下建立子目錄src，cd到該src目錄，執行如下命令建立工作包
catkin_create_pkg beginner_tutorials std_msgs rospy roscpp2.編寫釋出器和訂閱器
進入之前建立的beginner_tutorials包
roscd beginner_tutorials建立scripts目錄存放Python程式碼：
mkdir scripts
cd scripts下載例子指令碼talker.py到scripts目錄，並修改許可權為可執行(釋出節點):
wget https://raw.github.com/ros/ros_tutorials/kinetic-devel/rospy_tutorials/001_talker_listener/talker.py
chmod +x talker.py下載listener.py到scripts目錄，並修改許可權為可執行(訂閱節點):
wget https://raw.github.com/ros/ros_tutorials/kinetic-devel/rospy_tutorials/001_talker_listener/listener.py
chmod +x listener.py構建節點：
cd ~/hello_rospy catkin_make
3.測試釋出器和訂閱器
啟動釋出器：
開啟終端，輸入：
roscore確保roscore可用。
開啟新的終端，輸入：
如果使用catkin，確保你在呼叫catkin_make後，在執行你自己的程式前，已經source了catkin工作空間下的setup.sh檔案
cd ~/hello_rospy
source ./devel/setup.bash
rosrun beginner_tutorials talker.py此時你會看到如下資訊：
[INFO] [1534388269.223655]: hello world 1534388269.2233906 [INFO] [1534388269.323618]: hello world 1534388269.3233504 [INFO] [1534388269.423586]: hello world 1534388269.4233208 [INFO] [1534388269.523613]: hello world 1534388269.5233488 [INFO] [1534388269.623685]: hello world 1534388269.6233852 [INFO] [1534388269.723714]: hello world 1534388269.7234194 [INFO] [1534388269.823649]: hello world 1534388269.8233697 [INFO] [1534388269.923647]: hello world 1534388269.9233446 [INFO] [1534388270.023622]: hello world 1534388270.023337 [INFO] [1534388270.123665]: hello world 1534388270.1233444 [INFO] [1534388270.223655]: hello world 1534388270.2233653 [INFO] [1534388270.323668]: hello world 1534388270.3233645 [INFO] [1534388270.423637]: hello world 1534388270.423357 [INFO] [1534388270.523678]: hello world 1534388270.5233543 [INFO] [1534388270.623646]: hello world 1534388270.6233633 [INFO] [1534388270.723670]: hello world 1534388270.723355 [INFO] [1534388270.823638]: hello world 1534388270.8233557 [INFO] [1534388270.923635]: hello world 1534388270.9233434 [INFO] [1534388271.023646]: hello world 1534388271.0233815
釋出器節點已經啟動執行。現在需要一個訂閱器節點來接受釋出的訊息。
啟動訂閱器：
開啟新的終端，輸入：
cd ~/hello_rospy
source ./devel/setup.bash
rosrun beginner_tutorials listener.py此時你會看到如下資訊：
[INFO] [1534388451.225271]: /listener_32238_1534388451115I heard hello world 1534388451.2233224
[INFO] [1534388451.325214]: /listener_32238_1534388451115I heard hello world 1534388451.3234394
[INFO] [1534388451.425159]: /listener_32238_1534388451115I heard hello world 1534388451.4234073
[INFO] [1534388451.525082]: /listener_32238_1534388451115I heard hello world 1534388451.5234268
[INFO] [1534388451.624949]: /listener_32238_1534388451115I heard hello world 1534388451.6233602
[INFO] [1534388451.724969]: /listener_32238_1534388451115I heard hello world 1534388451.723355
[INFO] [1534388451.825018]: /listener_32238_1534388451115I heard hello world 1534388451.823384
[INFO] [1534388451.925162]: /listener_32238_1534388451115I heard hello world 1534388451.923369
[INFO] [1534388452.025092]: /listener_32238_1534388451115I heard hello world 1534388452.0234113
[INFO] [1534388452.125054]: /listener_32238_1534388451115I heard hello world 1534388452.1233687至此，全部完成。