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Using ikfast with 4DOF fails

asked 2015-12-04 07:47:26 -0500

Sietse gravatar image

Hello List,

to get my arm working in moveit, I try to create the ikfast code for a 4DOF with the commands:

rosrun collada_urdf urdf_to_collada my_robot.urdf my_robot.dae
rosrun moveit_ikfast my_robot.dae my_robot_rounded.dae 5
python `openrave-config --python-dir`/openravepy/_openravepy_/ --robot=my_robot_rounded.dae --iktype=translationxaxisangleznorm4d --baselink=1 --eelink=5 --savefile=ikf.cpp

This always fails. First there is a warning:

/usr/local/share/openrave-0.9/plugins/ cannot open shared object file: No such file or directory

But this file really exists!

Then at the end there is the following error:

File "/usr/local/lib/python2.7/dist-packages/sympy/matrices/", line 2580, in matrix_multiply
raise ShapeError()  

I tried to make the urdf as simple as possible, it only consists of the needed links and joints. The urdf-file can be found at HERE

I tried more complicated urdf's and they work. I use ros-indigo and openrave-0.9 on ubuntu 14.04.

Hopefully someone can help, thanks in advance.


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3 Answers

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answered 2016-02-01 14:10:25 -0500

Fredylucas gravatar image

When I generate my IKFast plugin for my manipulator, I must to install ROS Hydro for converting the URDF file to Collada, because Indigo didn't work.

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Thanks for this workaround. I'll will try that.

Sietse gravatar image Sietse  ( 2016-02-02 01:50:13 -0500 )edit

converting URDF to collada worked for me without any problems. I am running indigo igloo on Ubuntu 14.04 LTS

Chickenman gravatar image Chickenman  ( 2016-02-03 05:41:00 -0500 )edit

answered 2016-02-03 05:43:57 -0500

Chickenman gravatar image

updated 2016-02-03 05:49:16 -0500

I used sympy 0.7.0 and latest stable openrave and I can generate IK without any problems. with indigo I used this tutorial for openrave latest stable instalation

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answered 2016-02-02 02:24:35 -0500

Humpelstilzchen gravatar image

updated 2016-02-03 00:47:00 -0500

  • Please check if turns up in ldconfig -v.
  • Make sure you use an old python-sympy (version 0.7.1), newer do not work.

Btw why did you choose TranslationXAxisAngleZNorm4D? I don't see a translation in your urdf. It is not even implemented in the ros plugin, see ikfast61_moveit_plugin_template.cpp line 528

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Comments wasn't shown. I added it's directory to LD_LIBRARY_PATH, and the warning is gone. I have the correct version of sympy (via openrave install). But regrettably the error remains. Thanks.

Sietse gravatar image Sietse  ( 2016-02-02 15:00:11 -0500 )edit

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Asked: 2015-12-04 07:47:26 -0500

Seen: 599 times

Last updated: Feb 03 '16