Trajectory Stuck in loop!

[Muhammad Asif Rana]

Hi,

I am trying to make a robot arm pick an object, follow a trajectory through waypoints and then place the object at the target.

I am having the following problem:

1) Whenever I call group.computeCartesianPath(...) it automatically executes the trajectory as well which. Thats fine as well, but it keeps on going through the trajectory as if in a loop. I just want to go to the target, stop there and place the object.

2) Also, is there any way of checking and changing the robot-state while the trajectory is being executed? I want to see when the robot reaches a particular point and then detach the object from it.


This seems pretty trivial task and I am sure people would have done that. So, any code snippets/functions in C++ would help.



Thanks in Advance!

[Acorn Pooley]

Is the physical robot repeating this trajectory, or just the image of the robot in rviz?  Rviz will loop the last plan as long as PlannedPath->LoopAnimation is checked.

-Acorn

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From: moveit...@googlegroups.com [moveit...@googlegroups.com] on behalf of Muhammad Asif Rana [asif...@gmail.com]
Sent: Monday, April 07, 2014 12:40 PM
To: moveit...@googlegroups.com
Subject: Trajectory Stuck in loop!

[Muhammad Asif Rana]

No, not the actual robot. I am talking about the robot in Rviz.

How do you uncheck that? I am pretty new to ROS and moveit so pardon  me if this is a stupid question.

Further, can you help me out with the other tasks I am trying to achieve here. Like detaching the object and stuff.

[waldez junior]

All you have to do is to uncheck the box which says "loop animation" inside the planned path tab inside motion planning plugin in RViz =D

[Muhammad Asif Rana]

Is there a way to do it in code?

[waldez junior]

Im not sure, never looked into that really, but a quick fix would be to uncheck it and save the rviz configuration, the next time you launch it, the box should be unchecked already.

[Muhammad Asif Rana]

Hey thanks for the help.

I tried that and now its not looping anymore. However, the problem now is that the robot goes to final state and then disappears :/ Why do you think thats happening?

Moreover, do you know why the group.computeCartesianPath() and group.plan() functions executing the trajectories as well? I though they should just compute the trajectories only but not execute them.

Also, is there a way to know the state of robot during the trajectory execution. I wish to detach the object when it reaches a certain place.


Thanks!

[savan...@gmail.com]

Hello,

group.getCartesianPath and group.plan will just display the planned trajectory, by default in a loop.
If you want the trajectory to be executed, then you must call group.execute(plan).

group.getCurrentState will return a RobotState which can be used to get position of any link.

[savan...@gmail.com]

It doesn't exactly execute the plan when you do group.plan(&plan). It just displays the planned path. The state of the robot is not changed.

I guess you could turn off the planned trajectory display from Rviz settings checkboxes.

Hi,

Thanks for the reply.

I have to first call group.plan(&my_plan) to make a plan for me. Then, I want to do some other task before executing the plan using group.execute(my_plan).

However, group.plan executes the plan before letting me call the execution. Am I doing something wrong?