ROS2轻松学2-工具篇15-lifecycle演示讲义

ROS2轻松学2-工具篇15-lifecycle演示讲义

说明：　

• 介绍如何认识lifecycle
• lifecycle在于给节点增加一个生命周期管理,通过状态来更好控制节点处理流程

参考：　

• 中文教程1
• 英文教程1

lifecycle

• lifecycle帮助

ros2 lifecycle -h 

一步演示示例：

• 启动一步演示，完成生命周期管理

ros2 launch lifecycle lifecycle_demo.launch.py

分布步演示示例：

• 启动talker

ros2 run lifecycle lifecycle_talker

• 启动listener

ros2 run lifecycle lifecycle_listener

• 查看节点

ros2 lifecycle node  

• 查看节点状态

ros2 lifecycle get /lc_talker

• 查看可用状态

ros2 lifecycle list lc_talker　　 #查看可用状态机
ros2 lifecycle list lc_talker -a　#查看完整状态机

• 按顺序设置状态

ros2 lifecycle set /lc_talker configure
ros2 lifecycle set /lc_talker　activate
ros2 lifecycle set /lc_talker　deactivate
ros2 lifecycle set /lc_talker　cleanup
ros2 lifecycle set /lc_talker　shutdown

　- 按顺序执行，控制节点运行流程
　- 通过服务调用来获取状态

ros2 service call /lc_talker/get_state lifecycle_msgs/srv/GetState

　- 通过服务调用来设置状态

ros2 service call /lc_talker/change_state lifecycle_msgs/ChangeState "{transition: {id: 1}}"
ros2 service call /lc_talker/change_state lifecycle_msgs/ChangeState "{transition: {id: 3}}"
ros2 service call /lc_talker/change_state lifecycle_msgs/ChangeState "{transition: {id: 4}}"
ros2 service call /lc_talker/change_state lifecycle_msgs/ChangeState "{transition: {id: 2}}"
ros2 service call /lc_talker/change_state lifecycle_msgs/ChangeState "{transition: {id: 5}}"

　- ID: 1-configure 3-activate 4-deactivate 2-cleanup 5-6-7-shutdown
　- 找到对应的变换id

ros2 interface show lifecycle_msgs/msg/Transition
ros2 lifecycle list lc_talker -a