provides a number of valuable
advantages, including higher
performance and zero overloads.
Intelligent grabbing
technology
A full grab is crucial for high turnover
in bulk handling. The aim in the
development of SmartGrip was to
further develop the bulk handling
sector. The unique feature of SmartGrip
is having recourse to data collected on
the grab closing process. For the data
collection different cranes, grabs,
materials and the performance of
diverse-skilled crane operators were
considered.
Data mining
By means of the gathered information,
a model was developed using data
mining processes through which the
filling volume of grabs can be
optimised during the work process.
Based on the gained turnover
analyses from various ports around the
world, the data showed, on average,
only 70% of the grab capacity is used.
Moreover the utilisation of the cranes is
even worse due to unsuitable grabs.
This was affirmed with a test arranged
at Eren Port in Turkey with an optimal
grab, leading to an increase in turnover
from 1200 tph to 1800 tph (+40%). Those
results made clear that the biggest
leverage for turnover is associated with
the grab and its proper filling. The
analysis also showed that even a
properly selected grab is just a
compromise for a minor set of
conditions. Those conditions are:
n
n
Different ship sizes.
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n
Different materials.
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n
Different material densities.
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n
Material density changes (up to
20% per ship due to compression).
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n
Grab geometry.
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n
Grab hit angle.
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n
Skills of crane driver.
Suboptimal conditions can lead to
two possible situations:
n
n
The selected grab is too small,
which entails poor turnover results.
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n
The selected grab is too big, which
results in overloads that harm
the crane structure. Moreover
overloads are causing security
stops on the crane that are highly
time-consuming.
As a result, ports are faced with less
turnover (tph) than expected.
Mode of operation
The developed SmartGrip algorithm
learns the machine settings and material
properties autonomously. The
remarkable thing is that this is a
self-learning model: it adapts
continuously. By using various
parameters the system adapts to the
given reality and to the respective crane
operator. It will take the type of bulk
material, such as density, compression
and granularity, as well as current
conditions, such as material penetration
or type of grab, into account. The crane
requires no additional equipment like
specific sensors or cameras.
Furthermore, existing cranes can be
easily retrofitted with the appropriate
software.
Using SmartGrip, the driver controls
the closing of the grab. The system
controls the filling of the grab to the
optimum or a manually set load. This
enables optimal crane utilisation and
avoids overloads. Right from the second
load cycle, SmartGrip ensures that the
grab filling rate is above the average of
70%. Within a maximum of seven cycles,
the full capacity of the grab is utilised.
Valuable benefits
SmartGrip controls the filling of the
grab to suit the load curve of the crane.
This leads to perfect crane utilisation
without overloading, which results in
an extended lifetime of the crane,
saving fuel and time.
Moreover, when SmartGrip is
activated, the operator can completely
rely on the system for an accurate
determination of the material density
and optimal grabbing angle in a very
short time. The automatic and
optimised grab filling means less stress
for the crane operator, who can then
focus on other important issues like
safety.
In view of the average grab filling
rate of 70%, SmartGrip offers the
potential to fill the grab constantly to
the optimum. Additionally, turnover
variance is significantly reduced,
leading to more efficiency in
operation. Field studies showed that
even up to 40%, turnover increases are
realistic if the grab filling rate is below
average. Additionally, SmartGrip
partly closes the gap between
highly‑skilled and less-skilled drivers,
as some important parts of bulk
handling are automatically optimised
by the system.
Another striking feature offered by
SmartGrip is the possibility of
manually setting target loads. If a
crane operator needs to load a 40 t
Figure 2. Unloading sticky material can lead to strong forces on the crane structure.
62
|
World Coal
|
June 2015
