SMACH Usecase Question about executive_smach

[bajo]

@haritsahm this is quite similar to how I used smach a few years ago. Main difference would be that I had a combined task monitor / manager.
This would listen to certain inputs (eg. input from touch interface or speech reco, scheduled task events on ROS topics), do some simple rule-based decision making process and trigger the appropriate sub-state machine (eg. go_to_charging_station).
For us this would run for days, so no need to restart it after a task was finished.

[haritsahm]

@bajo I see, thank you. Another question, if an action state is running and there is a new task that needs to be executed immidiately, how to set that action state to stop?

[bajo]

If I remember correctly you need to first preempt the currently running ActionState, after that you can execute another one.

[haritsahm]

@bajo do you have an example of requesting a preempt of a running state from other task/state? The only available example in tutorial is using a concurrence with a monitor state

[bajo]

@haritsahm sorry, no public example to point you to. But I guess it depends how you are using the actionlib state. I think you just need to send a new goal to the running actionlib state, with a preempt request as message. See for example the tutorial at http://wiki.ros.org/smach/Tutorials/Simple%20Action%20State , especially the execute_cb of the TestServer.

[haritsahm]

@bajo I will try it later. Thank you!