Simple action client freezes at waitForServer(), command line possibility?

Question

Hi all,

I have followed the instructions and setup a navigation stack for my robot. I can control it very well with Rviz. However, when I wrote a program similar to the 'Simple Action Client' in the tutorials, the program waits forever at the waitForServer function. So sending goals through Rviz works, but simple action client does not. Any idea how I could debug this?

Also, is there a way to know through commandline whether the move_base action server is up? Perhaps, through the topics or services. I can see that most of the familiar move_base topics are running. Like I said earlier, I can control the robot through RViz. I would just like to verify the action server is running through commandline.

Edit April 10,2013: Does successfully sending commands through Rviz mean that the move_base action server is running? To me running the navigation stack implies running:

rosrun move_base move_base 

with all the parameters in a launch file. Is that sufficient to start the move_base action server?

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Originally posted by Shanker on ROS Answers with karma: 259 on 2013-04-09

Post score: 3

Answer 1

There is no verification afaik, besides looking at the topics.

You can try to connect to the server via a simple tool and test if something replies:

rosrun actionlib axclient.py /my_action

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Originally posted by dornhege with karma: 31395 on 2013-04-09

This answer was ACCEPTED on the original site

Post score: 3

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Original comments

Comment by Shanker on 2013-04-09:
What type of topic should '/my_action' be? Since Rviz sent a goal to the topic /move_base_simple/goal which is of type 'geometry_msgs/PoseStamped', I tried that. However I get an error similar to 'assert('Goal' in topic type)', which is quite self evident.

Comment by Shanker on 2013-04-09:
I then tried the topic '/move_base/goal' which is of type '/move_base_msgs/MoveBaseActionGoal'. I then do get the GUI, however there is a red error on the bottom of the GUI box which says 'No Goal and Disconnected from server'. I've tried to fill the fields in but it makes no difference.

Comment by dornhege on 2013-04-10:
I think it's just move_base. The /move_base_simple is not using actionlib.

Comment by Shanker on 2013-04-10:
Right. I have added an edit to my question. It relates to how to start the move_base action server. I would appreciate if you could look at it. Thanks..

Comment by Shanker on 2013-04-10:
In the actionclient GUI, is 'Disconnected from server' the default/start statement?

Comment by dornhege on 2013-04-10:
move_base should be the node to run "everything". It might not come up properly if misconfigured, but there should be warnings. Thus, when rviz works usually the actionclient also works, although it's not 100% guaranteed as rviz uses another mechanism.

Comment by Shanker on 2013-04-14:
That's what I thought as well. Rviz works perfectly, yet the autoclient does not. Also, the simple action client does not work as well. It waits indefinitely as I mentioned at waitForServer().

Comment by dornhege on 2013-04-14:
/move_base should be the action to connect to. There should be actionlib related topics in the move_base node. If not, something is wrong.

Comment by Shanker on 2013-04-19:
I was using multiple clients and servers and connecting to the wrong one. Your answer of using the GUI client is the right one.