Cucumber Cutting, magnetically tracked

This page hosts some experimental data from cucumber cutting which was recorded with the magnetic motion tracker 'Razor Hydra ™'.

The following images show the setup before the start of the experiment.

Then, the cucumber was cut into slices, starting from the right end (phase1). after about cutting half of the cucumber, the knife was put aside and the cucumber was moved:

Then the cutting continued (phase2) until all of the cucumber was cut.

Beware: This may be a challenging dataset due to systematic errors in the tracking device. Hopefully, these errors are small in the relevant workspace.

The origin is in the green ball (the emitter), with z pointing down, y pointing to the left and x pointing towards the cutting person.

I tried to identify points of interest, both on the tool and in the scene.

Until the calibration code for that is polished, I post the calibration points here in text form.

tip-of-blade:

[0.29293112, 0.03024254, 0.03524071]

grip-end-of-blade edge:

[[ 0.16761572] [ 0.00385015] [ 0.04192011]]

normal of the blade:

pose of the paddle, when the blade is lying flat on the board:

[[    0.993666,    0.073076,   0.0853739;
    -0.105184,    0.337344,    0.935487;
    0.0395613,   -0.938541,    0.342893]
[       -0.62,       0.164,       0.144]]

lying on the other side (here, the mounting of the paddle was bending noticably):

[[    0.948797,    0.313658,   0.0374525;
     0.160745,   -0.377344,   -0.912016;
    -0.271929,    0.871338,   -0.408442]
[      -0.621,       0.162,       0.225]]

table corners:

[   -0.479589,     -0.3937,    0.204708]
[   -0.375432,    0.196603,    0.174091]
[third corner is nonsense]

cutting board (highly distorted):

[   -0.618805,   -0.127104,   0.0772075]
[   -0.475962,    0.179408,   0.0621018]
[   -0.174584,    0.142956,   0.0148497]

The cucumber ends on the board were as follows:

cucumber ends:

[   -0.504385,   -0.126844,    0.226978]
[   -0.422555,    0.285663, -0.00650265]

Then, I did two recordings of cutting (phase1), then I moved the cucumber:

cucumber ends (second round):

[   -0.410377,   -0.109242,    0.311248]
[   -0.470199,    0.136546,    0.143661]

Then the recording phase2 happened.

• The ros bags with the recordings are here.

• The cutting itself is also avaliable as gnuplot/matlab compatible text files here.

• The data are transformed from the Hydra message format to a geometry_msgs/TransformStamped message by the node hydra_tf_node.

• The code is in my sandbox in hydra_tf_node and calib_tools:

hg clone http://toychest.in.tum.de/users/kresse/sandbox