charts were complete,
it was a matter of
converting them to the
robot code, KRL. This
language is proprietary
for the KUKA robots."
Ice cream sundae
construction is split
between an ice cream
robot and a toppings
robot. The programming
of the latter enables it
to select one of six
different toppings based
on choices made by
customers at the touch panel. The
same programming also enables the
robot to wait for data from the
camera coming through the high
speed serial connection to tell it where
the spoon is located.
In addition, the robot must know
the orientation of the spoon so it
does not place it in the cup of ice
cream the wrong way. To do this, the
robot relies on the VisionPro software
to compute a rotation angle for the
robot to use to adjust the alignment
of the spoon and put it in the ice
cream just right.
As for the KUKA robot assigned
to the ice cream itself, this bot moves
based on inputs from the touch panel,
delivered through the PLC. "The
code in the ice cream robot is pretty
unintelligent, that is, it just moves
through several points and waits while
ice cream is dispensed and then
returns to a position."
The VisionPro software runs on a
PC. "The software receives images
from the camera, analyzes them, and
relays the location of the spoon to
the robot by way of an RS-232 serial
connection. The vision system was
programmed by first giving it a
training image of the spoon. That is,
an image was taken of the spoon and
recorded in the VisionPro software.
Then, the software was told that this
was what it should be looking for. It
was also told at what point on the
spoon it should consider its origin and
at what angle the training spoon
image was. Then, the program was
set up to find this spoon, its location,
Robot arm releases selected toppings into cup.
and its angle of rotation, and
then relay that information to
the robot via the serial port."
The PLC sequencer was
programmed in simple Ladder
Logic, using the RSLogix500
"It is a very simple program
with only a few lines of code.
It takes the topping selection
button push from the touch
panel, remembers it, then
transmits it out to the robots
when the Go button has been
pushed on the touch panel."
A side shot of the entire robotic ice cream
As mentioned earlier, a
Flea2 Fire Wire camera fitted
with a 9 mm lens was used.
Optical calculations derived the
ideal location for the camera in
relation to the area where the
spoon would be placed.
After the VisionPro was
trained in spoon identification,
in operation it locates a predetermined point on the spoon within
that image, down to the pixel.
Next, the computer vision
software runs some vision related
equations that relate the selected
pixel position to the real-world
measurement and placement of that
part of the spoon in millimeters.
The computer forwards that value
to the robot via RS-232 serial
"Along with that location is an
angle of rotation that when applied,
Customers making selections at interface.
yields a grasped spoon in an ideal
orientation for the next task. That is,
it has been relocated from a random
position to a position that the robot
knows." This is the core of part bin
picking. The robot accomplishes this
maneuver mechanically using a
suction cup that attaches to the spoon
at the widest point of its handle.
As with any automated work cell,