Application Report
Goodbye index cards!
Leuze electronic sensors help to automate the book-lending process in
modern libraries
In large libraries, self-service dominates everything from check-out to
return. But very few users stop to think about how the returned media are
sorted. Assisting here are automated processes with flexible transport sys-
tems from Swisslog-Telelift and sensors from Leuze electronic.
The German National Library in Leipzig makes nearly 25 million pieces of media
available to its users. Every day, thousands of these are used, lent out and re-
turned. This massive quantity can only be handled by means of automated proc-
esses. Moreover, fast access times, shorter paths and more economical proc-
esses are demanded – this is true not only at the German National Library, but
also at the Jacob-und-Wilhelm-Grimm-Zentrum of the Humboldt University of
Berlin ("The Grimm Library") and the Berlin State Library.
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Transport solutions from Swisslog-Telelift make a key contribution in these large,
renowned libraries towards ensuring that order processing is accelerated and that
personnel are relieved of manual transport tasks (figures 1a and 1b). The highly
automated operational procedure, which spares the users of unnecessary wait
times at the loading and unloading points, calls for reliable, highly-integrative
sensor solutions from Leuze electronic (figure 2). For Jörg Franke, project man-
ager for transport systems for light goods at Swisslog-Telelift, the advantage is
obvious: "Returned books can again be made available more quickly. This brings
the users a trued added value and is, without a doubt, a quality feature of the
library."
Specialist in the area of light transport technology
Headquartered in the Bavarian city of Puchheim, Swisslog-Telelift is part of the
Swisslog Group and is a leading manufacturer of conveyor systems for the in-
house transport of lightweight goods and documents. In addition to rail-based
transport systems, this manufacturer also produces driverless transportation sys-
tems with a maximum capacity of 500 kg.
In the library sector, the company handles the entire logistics process, from book
return, to sorting, to the targeted transport to the stacks. All Swisslog-Telelift
transport systems can be integrated according to individual requirements in the
now-standard self-service lending logistics systems used in libraries – i.e. even in
the customer terminals where media are checked out and returned (figure 3).
Jörg Franke describes the service portfolio: "We develop and manufacture modu-
lar systems for nearly all requirements and offer the customer everything from a
single source – from design and planning to construction and start-up. In the area
of sensor systems, we have, for a long time, worked together successfully with
the specialists from Leuze electronic."
MultiLift with Leuze electronic sensor systems
At the two large libraries in Berlin – the university library and the state library – as
well as at the German National Library in Leipzig, solutions were implemented
during the course of renovation work that allow books to be transported in non-
driven transport boxes on conveyor systems and in lifts ("vertical conveyors") to
the intended location. The "MultLift" system was used in these applications. This
fundamental technology concept from Swisslog-Telelift consists essentially of
conveyor belt sections and roller conveyors for the horizontal transport within a
building floor as well as fully automatic container lifts for the vertical transport
between individual building floors (figures 4 and 5).
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Book transport containers with a maximum capacity of 25 kg are used to trans-
port the media. The MultiLift system operates with a direct destination control
(figure 6). Jörg Franke explains how it works: "The transport destination is set on
code carriers that are located directly on the transport container. These can be
either slider coding bars or rotary coding discs. The contactless destination que-
ries performed by the Leuze electronic BCL 34 barcode readers detect the desti-
nation setting at all decision points along the transport system. As a result, the
containers reach their destination quickly and reliably."
In the Grimm Library in Berlin, rotary coding discs from Leuze electronic are used
(figure 7). With these, the codes can be quickly and easily set by hand with a
turning motion. In contrast, the slider coding bars used at the state library and at
the German National Library offer unlimited "nesting" capability (figure 8). This
means that the containers can be optimally stacked horizontally within one an-
other. Jörg Franke says: "This saves an enormous amount of space, for example
in the German National Library, where some 350 containers are used."
Data transmission via PROFIBUS
The barcode readers are equipped with an integrated PROFIBUS interface. This
eliminates the need for PROFIBUS gateways and RS-232 components, consid-
erably reducing the costs for the entire system. The BCL 34 barcode readers
read the codes that have been manually preset on the slider coding bars (fig-
ure 9) and transfer the data via PROFIBUS directly to the control. This can then
positively identify the destination of each detected container. The barcode read-
ers support a maximum signal transmission rate of 12 MBd.
The devices are programmed directly with the software tool of the PROFIBUS
master, i.e. no other tools are needed for configuration. If necessary, it is possible
to exchange a barcode reader in just seconds without any special technical know-
ledge. The BCL 34 state can be queried and monitored directly by the
PROFIBUS diagnostics tool.
Distance measurement in the lift
For a high transport capacity and to overcome the large transport heights be-
tween the individual building floors, a continuous container lift that functions simi-
lar to a paternoster is used in the Berlin State Library. In the Grimm Library, on
the other hand, a linear lift is used to connect the eleven floors to one another.
The MultiLift lift systems are loaded and unloaded fully automatically during both
upward as well as downward travel. During this process, the doors automatically
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and reliably close by means of an electromotor after each loading and unloading
operation. For the vertical movement of the containers in the lift, the control uses
the signals provided by the AMS 200 laser distance measurement devices from
Leuze electronic. With these devices as well, the signals are transmitted via
PROFIBUS. Thanks to the integrated interface, they can be easily and economi-
cally integrated in the PROFIBUS network. The sensors achieve an absolute
accuracy of +/- 2 mm over a measurement distance of 120 m. Due to the ex-
tremely fast position calculation in the device, the high dynamics of modern drive
technology can be used to their full potential (figure 10).
AMS 200 distance measurement devices increase system safety through the use
of prefailure messages. With these warning signals, the devices inform the user
in good time of decreasing laser diode performance, impermissible temperatures
or soiling of the optics. The early warning and subsequent maintenance work
provide additional reliability and availability.
Good results right from the start
All in all, the technological alliance between Swisslog-Telelift and Leuze elec-
tronic ensures that a visitor to the library quickly obtains his or her book at the
check-out/return terminal and can again return it there with ease after reading. By
using the type of automation described here and by networking the control via
PROFIBUS, books can be returned to the stacks and again made available for
use in just minutes, even over long distances in multiple buildings and over sev-
eral floor levels. This should make future book readers happy, even if the tech-
nology that makes it possible isn't apparent at the customer terminal.
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Selection of images and captions
((Alternative lead photo:))
Handling area for books: the reader terraces in the Jacob-und-Wilhelm-Grimm-Zentrum of
the Humboldt University Library in Berlin ("Grimm Library")
Figure 1 a, b. Swisslog-Telelift light conveyor systems for the automated transport of
books in libraries
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Figure 2. Transport solutions with Leuze elec-
tronic coding bars for the barcode readers pro-
vide greater efficiency in handling the book
quantities encountered in large libraries.
Figure 3. Service terminals for checking out
and returning books
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Figure 4. The container moves quickly to-
wards the vertical conveyor – a fully automatic
lift that functions similar to a paternoster to
transport books between the individual levels
of a building.
Figure 5. The inner workings of the vertical
conveyor contains highly dynamic drive ele-
ments and reliable sensors at the PROFIBUS.
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Figure 6. Barcode readers on the transport
path read the preset codes as the containers
pass through and transfer the data to the con-
trol via PROFIBUS.
Figure 7. The presetting on the container can
be made with either slider coding bars or, as
shown here, with rotary coding discs. With the
latter variant, the worker can easily and
quickly set the destination for the container
transport with a turning motion.
Figure 8. Unlike rotary coding discs, con-
tainers with side-mounted coding bars can
be optimally stacked inside of one another,
i.e. they can be nested and stored in a
space-saving manner.
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Figure 9. The coding bars are set by sliding
red positioning elements so that they cover
certain barcodes for the readers.
Figure 10. The AMS200 laser distance meas-
urement device from Leuze electronic trans-
mits the signals for moving the vertical con-
veyor to the control via PROFIBUS.
Press inquiries
Leuze electronic GmbH + Co. KG
Matthias May, Tel. +49 8141 5350-123
matthias.may@leuze.de, www.leuze.com
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