SAMPE Journal - November/December 2020 - 18

FEATURE / COMPOSITES KIT TING SYSTEM

Figure 2. Overview of the Automated Kitting system with numbered main components.

The process is started by selecting the correct
operational mode on the HMI that is integrated
into the main cabinet (5). Identification of plies is
done by scanning a barcode with a barcode reader
(8). The information belonging to that specific ply
is loaded from a database that contains information of the all the plies. In section that follows, more
information can be found about the database management system. The ply is placed on a conveyor
belt (7) which transports the ply into the robot cell
(4). A line scan camera (6) - that is part of the machine vision system - creates an image of the ply
shape from which its position and orientation on
the belt is determined. It also recognises the ply
and will compare this with the ply information in
the database as an extra check. A proprietary algorithm -the picking algorithm - calculates the correct position and orientation of the end effector
(10) as well as the correct suction cup pattern to activate. When the ply arrives at the correct spot, the
conveyor belt (7) is stopped and the ply is picked
by the suction cups on the end effector (10) that
is mounted on a six-axes robotic arm (11). The robot places the plies into the buffer (3) that consists
of 40 vertically stacked aluminium plates that are
called trays. If the picking algorithm is unable to
calculate a valid pick instruction, the ply ends up
on a sliding plate (2) at the backside of the conveyor belt (7). The operator can then either place them
again on the conveyor belt for automatic sorting
and sequencing, or add the ply manually to the kit
at the end of the process.
Database Management
The Automated Kitting system needs to make onthe-fly decisions based on live information. As
plies can be inserted at random positions and orientations, at different moments in time, and in any

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order, a database management system is crucial. A
track and trace system keeps up-to- date information about each ply in the Automated Kitting system and logs the history of each individual ply.
When a ply is inserted in the machine, it is
identified and evaluated based on information
available in the database. The database is updated
periodically with work order information from an
Enterprise Resource Planning (ERP) system and
continuously during the process by incorporating
data from a Programmable Logic Controller (PLC)
based machine controller connected to various sub
systems, sensors, and actuators.
The information in the database is directly used
to control the machine: e.g. a destination tray is assigned to a new ply, it is decided how to pick up a
ply from the conveyor and the kit sequence steps
are calculated based on live information.
Picking Algorithm
Each individual suction cup on the end effector can
be activated on its own to match with the ply geometry to be picked-up. This is essential to limit vacuum loss, but more importantly not to accidently
pick-up any other ply. This pattern is generated by
the picking algorithm. After determining the shape
of the ply with machine vision, the system calculates how to pick the ply from the conveyor. First
a check is done to confirm that the detected ply
shape corresponds to the expected ply shape and
to eliminate possible folds or overlaps in material.
This check is followed by a calculation of a pick
instruction, which is different each time a ply is inserted, as it depends on the exact placement of the
ply. The calculation further considers the possible
internal cuts in the ply and the material stiffness to
ensure the ply can be picked and placed securely.
Materials with low stiffness will sag more easily and

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SAMPE Journal - November/December 2020

Table of Contents for the Digital Edition of SAMPE Journal - November/December 2020
