IKFast

Creating the IKFast plugin

Descartes has been designed to be used with IKFast. This means that an IKFast solver plug-in must be build for the robot to be used. All of the steps below have been performed on Ubuntu 14.04 and ROS Indigo.

To build the IKFast plug-in the following tools are required:

collada_urdf

sudo apt-get install ros-indigo-collada-urdf

moveit_kinematics

sudo apt-get install ros-indigo-moveit-kinematics

openrave

sudo apt-get install ros-indigo-openrave

sympy 0.7.0

sudo pip install sympy==0.7.1

Patching create_ikfast_moveit_plugin: The current version of the script on Indigo has a problem, as it generates ambiguous Isnans. By applying the patch detailed here: https://github.com/gavanderhoorn/moveit/commit/5d4e3a842bc279f168cf5edb0b7f0c81dd0e3bfe this can be solved. The script can be edited using the following command:

sudo nano -c /opt/ros/indigo/lib/moveit_kinematics/create_ikfast_moveit_plugin.py

First generate a collada file of your robot URDF:

cd irb120_pen_support/urdf
rosrun collada_urdf urdf_to_collada irb120_pen.urdf irb120_pen.dae

Check this model using openrave:

openrave.py irb120_pen.dae

Check for the link names:

openrave-robot.py irb120_pen.dae --info links

When the links are correct, use openrave to generate the C++ source for IKFast:

python `openrave-config --python-dir`/openravepy/_openravepy_/ikfast.py --robot=irb120_pen.dae --iktype=transform6d --baselink=1 --eelink=11 --savefile=ikfast61_irb120_pen_manipulator.cpp

Create a MoveIt robot support package, if it does not exist yet. Add all links to the kinematic chain group called manipulator:

roslaunch moveit_setup_assistant setup_assistant.launch

Create the package that will become the IKFast plug-in:

catkin_create_pkg irb120_pen_ikfast_manipulator

Generate the IKFast plug-in, this will also update the MoveIt support package to use the IKFast solver:

cd irb120_pen_support/urdf
rosrun moveit_kinematics create_ikfast_moveit_plugin.py irb120_pen manipulator irb120_pen_ikfast_manipulator ikfast61_irb120_pen_manipulator.cpp

Lastly, compile all:

catkin_make