Trumpf BendMaster 150, Operator'S Manual

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ble manual control unit and the press brake in real time and
linked to the control cabinet of the BendMaster.
3.5 Sheet sensor
The BendMaster is operated with a sheet sensor used to identify
the position of the workpieces.
The sensor head consists of two CCD cameras (rough and fine
recognition), four diodes that collectively generate a green flash
and a green diode laser for height measurements.
The performance data is recorded and evaluated by an industrial
PC in the switch cabinet of the BendMaster.
The sheet sensor performs the following three functions one
after another:
■ Rough recognition of the workpiece stack.
■ Height measurement of the workpiece stack.
■ Fine recognition of the workpiece.
The camera takes a picture of the pallet with workpiece stacks.
It may be composed of several individual images. The working
area lighting of the BendMaster is used for this purpose.
CAD data of the workpiece is saved in the computer. This data
is used to create reference models. The respective pattern is
searched for in the recorded image and the position of the work-
piece is determined if the pattern is found.
This position data is used to bring the sensor head into the right
position for height measurement and/or fine position recognition
of the workpiece.
The rough recognition process only has to be performed once
for each loading cycle, since the pallet with the workpiece stacks
can no longer be moved after loading the bending cell.
The precise distance between the workpiece and the gripper
must be determined. A diode laser projects a laser cross into the
camera vision range for this purpose. The distance is calculated
by means of triangulation.
The height of each workpiece stack is measured once by
default. The BendMaster automatically calculates the height of
the remaining workpiece stack since it knows the sheet thickness
of the workpiece.
The height of the workpiece stack can be measured after every
xth workpiece. Potential errors due to inaccuracies of the sheet
thickness are compensated for in this way.
3
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8
The most important assemblies 2015-06-01
B579EN
Sensor head
Signal processor
Sheet sensor functions
Rough recognition of the
workpiece stack
Measurement of the
workpiece stack height