How to calibrate the transformation between hand and eye:

Preparations:
* place the camera on the gripper
* place a checkerboard somewhere visible to the camera and fix it
* move the robot arm around the checkerboard and write down some joint poses 
  as calibration path in data/calibration_path.yaml (minimum 4),
  be sure that the checkerboard is fully visible inside the camera image in each
  calibration pose


Run software:
!!! PLACE YOUR HAND ON THE EMERGENCY STOP OF THE ROBOT BEFORE THE NEXT STEP !!!
!!! AND WATCH CAREFULLY THAT THE CABLE DOES NOT GET STUCK                   !!!
* roslaunch arm_camera_calibration calibration.launch

If everything works fine, the calibration procedure should steer the robot into
the poses that are given in calibration_path.yaml and write pattern and arm poses
to two files in arm_camera_calibration/: pattern_poses.txt and arm_poses.txt.
When all poses are written the launch file gets shut down.

* cd octave
* ./calibration ../arm_poses.txt ../pattern_poses.txt
This runs the transformation computation using the written arm_poses.txt and
pattern_poses.txt
The transformation is printed on the screen. Use the last column of the matrix
as translation and the RPY values for the rotation to configure the 
hand eye tranformation as parameters in the arm_control package.