Descartes finding discontinuous path

asked 2019-05-24 10:27:47 -0500

jbeck28 gravatar image

I am currently trying to plan circular paths in moveit, using Descartes. Although I've compared the output with the built in cartesianpath functionality in Moveit, and have found that it comes up with a much smoother path than Descartes does. The Descartes path is riddled with instantaneous joint flips.

At first I thought this might be due to using TRAC-IK , so I figured out the parameters for OPW for the fanuc lrmate200id that I'm using, and I've found that even still, the path generated in descartes is quite bad.

Any ideas on where to look to solve this problem?

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Comments

Most problems with Descartes are caused by an incorrect or improperly configured IK solver. How are you using OPW exactly? And how are you configuring Descartes to use it?

gvdhoorn gravatar imagegvdhoorn ( 2019-05-24 11:08:00 -0500 )edit

Descartes interfaces with moveit via https://github.com/PickNikRobotics/de... so I'm essentially using the typical ComputeCartesianPath functionality in move group.

for OPW, I'm using the moveit_opw_kinematics_plugin https://github.com/JeroenDM/moveit_op... where I've configured my own kinematics.yaml file with values that I've determined to be correct by looking through the documentation for the Fanuc LRmate200id (note I intend to use this on an IRB1200 as well, but fanuc for now). The values I've found seem correct (enough) since motion plans work fine for individual points.

Thanks for responding so quickly!

jbeck28 gravatar imagejbeck28 ( 2019-05-24 12:51:44 -0500 )edit

Descartes interfaces with moveit via https://github.com/PickNikRobotics/de...

I'd say it's the other way around, as this allows MoveIt to use Descartes.

In any case: I'd suggest to post an issue over at the PickNikRobotics/descartes_capability tracker. The MoveIt capability is a custom wrapper and I've not checked the code.

As I wrote earlier, problems with Descartes are often caused by IK solvers that don't return sufficient solutions for poses or by incorrect setup of the Descartes planning infrastructure. Only the PickNikRobotics/descartes_capability know how they set things up / are using it. I don't think ROS Answers is the correct venue here.

gvdhoorn gravatar imagegvdhoorn ( 2019-05-24 13:21:59 -0500 )edit

Post on the PickNikRobotics/descartes_capability tracker: PickNikRobotics/descartes_capability#4.

gvdhoorn gravatar imagegvdhoorn ( 2019-05-25 02:53:50 -0500 )edit