PROJECT DELIVERABLE D5
SITE INFORMATION
Shared-cost RTD
Project acronym: TOURBOT
Project full title: Interactive Museum Tele-presence through Robotic Avatars
Contract Number: IST-1999-12643
Key Action:
3
Action Line:
3-2-3
Site Information
Project
Deliverable
TOURBOT: Interactive Museum Tele-presence Through Robotic Avatars
Project Deliverable D5: Site Information
Date Produced:
September 27, 2000
Authors:
Dirk Schulz, Dirk Haehnel, Wolfram Burgard and
Panos Trahanias
Contents
1
2
Introduction .................................................................................................................. 3
Map Construction ......................................................................................................... 4
2.1 Building Grid Maps ............................................................................................... 4
2.1.1 Laser-based Implementation ........................................................................... 4
2.1.2 Maps of the Museum Sites .............................................................................. 5
2.2 Map Updating ........................................................................................................ 7
2.3 Maps for User Interaction ...................................................................................... 8
3 Multimedia Information ............................................................................................. 11
3.1 Intended Web Interface ....................................................................................... 11
3.2 Information about Exhibits .................................................................................. 12
3.2.1 Foundation of the Hellenic World ................................................................ 13
3.2.2 The Deutsches Museum Bonn ...................................................................... 16
3.2.3 The Byzantine and Christian Museum of Athens ......................................... 20
3.2.4 The Data Collection ...................................................................................... 25
4 Publications ................................................................................................................ 25
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Introduction
One of the major tasks of the TOURBOT system is to navigate safely and reliably
through the museum’s premises, controlled by Web users and providing camera images
and multimedia information about exhibits. To fulfill this task, the system requires
different kinds of site information, e.g. information about the environment the robot is
operating in and about the exhibits the robot is showing to the users. This deliverable
documents the site information acquired and the methodology employed to obtain the
environment information required for the operation of the robotic system.
The site information can roughly be divided into two parts. The first relates to the robotic
system, which needs information about the exhibition area, in order to be able to navigate
safely and reliably in it. For mobile robots, this information is generally provided in the
form of a map of the environment, which the robot uses to keep track of its position
within the environment. These navigation maps can be constructed automatically from
sensor information that the robot collects within the museum. Therefore, the first part of
site information refers to the map building process and the actual maps that were
constructed for the three user sites; we document the map-building methodology
employed by the TOURBOT system and the workspace maps that were obtained using
the system.
The second part of the site information relates to the users of the system. It is the actual
information about exhibits, which the system presents to the user through its interface. In
general, this can be any kind of multimedia content that can be presented using standard
(Web) browsers. For the case of the TOURBOT system, there are specific issues that
need to be considered: TOURBOT is an on-line system, since the robotic platform moves
through the museum, while a user is observing. Therefore, the system’s interface must
continuously inform the user about the robot’s current position and actions.
Consequently, maps need to be created which are user-perceivable and which can be used
to indicate the robot’s position in the museum workspace. The information about exhibits
should be provided just-in-time, e.g. when the robot arrives at the exhibit and looks at it.
We will document the maps for user interaction that have been constructed, the
multimedia material for the museum sites we compiled, and how this material can be
accessed.
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Map Construction
In order to effectively and safely navigate within the museum, the robot requires an
internal model of its environment. The representation of choice for this model is maps.
Using a map of the environment, the robot is able to localize itself, e.g. to continuously
keep track of its current position within the environment. Such a map, therefore, provides
the global coordinate frame of the TOURBOT system. The position of the robot, as well
as the location of the exhibits, are specified (as coordinates) within this map.
2.1
Building Grid Maps
TOURBOT employs a probabilistic method, known as Bayesian map building, to
construct the maps of the museum sites. A fast real-time variant of this method has been
developed by participants of the consortium and an implementation of it has been
undertaken for the TOURBOT project. Bayesian map building allows to automatically
derive grid maps from sensor data. Grid maps divide the environment into a rectangular
grid of equally sized cells, where each cell contains the probability that the corresponding
space in the environment is occupied.
Using a probabilistic technique known as Bayesian inference, these probabilities can be
determined from proximity sensor data that the robot collects within the environment.
Proximity sensors measure the distance to obstacles in the surroundings of the robot.
Based on (unreliable) position information provided by the robot’s drive and based on a
model of the sensor used, the map building process then computes the probability that a
certain cell of the grid is occupied, given the sensor measurement received. Bayesian map
building integrates subsequent sensor measurements, in order to obtain a complete grid
map of the environment.
2.1.1 Laser-based Implementation
The main sensor used by TOURBOT is a laser range-finder, which measures the distance
to obstacles in a horizontal plane. The actual sensor used operates with an angular
resolution of 1 degree and provides 180 measurements per scan and about 5 scans per
second, that way, covering half of the robot’s surroundings. The device is very accurate
with an average measurement error of only 5 cm. Figure 1 illustrates the concepts. The
left part of Figure 1 shows one scan taken within the Deutsches Museum Bonn. This scan
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has been taken by the robot RHINO (see Figure 3), which is equipped with two laser
range-finders. The right part of Figure 1 shows a grid map constructed from that single
scan using a resolution of 10 cm per cell. The complete map, shown in Figure 5, was
integrated from 3365 scans.
Figure 1 A 360 degree laser range scan (left) and the resulting grid map (right).
2.1.2 Maps of the Museum Sites
During a TOURBOT meeting in Athens, on March 15-16, 2000, we recorded the laser
data for the exhibition rooms at (a) the Foundation of the Hellenic World and, (b) the
Byzantine and Christian Museum of Athens. For this purpose, the robotic platform Sam
was used (see Figure 2 and Figure 3) that roved through the exhibition areas. Note that,
although this robot's hardware differs from the hardware of the TOURBOT system, it
runs the same navigation software and the same laser range-finder is used.
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Figure 2 The robot Sam collecting laser data in the Byzantine and Christian Museum of
Athens.
Figure 3 The robotic platforms used to perform mapping of the user sites; (left) the robot
Sam within the Foundation of the Hellenic World; (right) the robot RHINO within the
Deutsches Museum Bonn.
Based on the data recorded, the TOURBOT map builder constructed the 2 maps shown in
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Figure 4. The resolution of these maps is 10cm per cell. The data for the Deutsches
Museum Bonn has been recorded in another session using the robot RHINO (also
depicted in Figure 3). The resulting map is shown in Figure 5.
Figure 4 Navigation grid maps; (left) Byzantine and Christian Museum of Athens, (right)
Foundation of the Hellenic World.
Figure 5 Navigation grid map for the Deutsches Museum Bonn.
2.2
Map Updating
The map building module, as described so far, is intended to construct static maps, e.g.
they show the museum environment as it appears when the museum is closed to visitors.
However, during the operation of the TOURBOT system, the museums will be open to
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the public and visitors will be walking around. In order to cope with the dynamic changes
within the environment, for example to plan detours around groups of people, the robot
must be able to maintain its map over time. Therefore, the TOURBOT system
implements on-line map updating. It continuously integrates recent laser data into the
static map to obtain maps which provide snapshots of the current state of the robot’s
surroundings. In these maps, groups of people and other objects (obstacles) appear as
occupied space enabling the robot to plan detours.
2.3
Maps for User Interaction
In its normal mode of operation, the TOURBOT system is controlled by inexperienced
users, either remote (Web) users or on-site users. To keep the user informed about what
the robot is currently doing, the actions of the robot must be reflected in the user’s Web
interface. The robot’s localization component continuously maintains its current position
within the museum based on the grid map. In principle, these maps can be used inside the
Web interface to communicate the robot’s current position to the user. However, nontechnical users are not familiar with concepts and terminology from the field of robotics
and, moreover, maps built from sensor data are not particularly intuitive. At the same
time, they do not contain any information about the location of exhibits and of any
objects that can not be detected by the robot’s sensors.
For user interaction, we therefore use CAD maps, which resemble well known floor
plans. These plans are aligned with the grid maps, e.g. they have the same size and can
also be used to indicate the robot’s position to the user; additionally, they are annotated
with information regarding the position of the exhibits. Figure 6, 7 and 8 show the maps
for user interaction for the Foundation of the Hellenic World, the Deutsches Museum
Bonn and the Byzantine and Christian Museum of Athens, respectively. It is quite
straightforward to compare these maps with the navigation maps that have been
autonomously built from sensor data. The similar structure of the two kinds of maps is
evident and also differences are quite obvious. The navigation maps (machine oriented)
are clearly probabilistic in nature and they show several exits from the exhibition area,
which the robot will never use. The latter might confuse the Web user and are omitted in
the interaction map.
The robot navigates autonomously using the navigation maps, which are constantly
updated, and the robot’s current position is permanently displayed inside the user
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interaction map using Java applets. In this context, the need arises to explain the robot’s
course of action to the Web user. For example: “Why does the robot take this detour,
although there is free space in the map?”. For this purpose, techniques to estimate the
current position of objects and of people walking around have been developed. This
information will be used by the TOURBOT system to update the user interaction map
accordingly. It is our goal to display not only the robots current position, but also the
detected changes within the environment.
Figure 6 Map for user interaction of the Foundation of the Hellenic World indicating the
position of the 22 exhibits.
Figure 7 Map for user interaction for the Deutsches Museum Bonn, indicating the 26
exhibits.
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Figure 8 Map for user interaction for the Byzantine and Christian Museum of Athens.
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Multimedia Information
The major task of the TOURBOT system is to present museum exhibits to visitors, either
over the Web or on-site. Web users observe the exhibits through the robot’s cameras and,
moreover, get additional information pertinent to the exhibits. TOURBOT achieves this
by combining the advantages of a mobile platform with the Web’s capability to transmit
and display almost any kind of multimedia material. In this section we present the
compilation of the system’s information base, consisting of multimedia material from the
three end-user (museum) sites.
3.1
Intended Web Interface
The presentation of multimedia material is innately coupled with various aspects of the
Web interface. Although the final design of the TOURBOT Web interface has not settled
yet (interface design is a subject for work package 7), it is clear from our earlier
experiences with web-controlled robots that, for the most part of an application, the
interface must be contained within one web-page. As a consequence, robot-control and
information feedback share the same page, putting thus restrictions on the possible
presentation of multimedia information.
Figure 9 shows a first version of the TOURBOT Web interface. The page is divided in
two parts (left part and right part); in addition, self-explanatory buttons are used for
analogous tasks. The lower left part contains the robot control interface; the upper left
part is the video window where the user observes the viewed scene. The right part is used
by the TOURBOT system, to display just-in-time information about exhibits. Just-in-time
is interpreted in our case that information about an exhibit will show-up as soon as the
robot arrives at it. The user will then be able to browse through the information on the
exhibit.
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Figure 9 Prototypical TOURBOT Web interface. The lower left part is dedicated to robot
control; the upper left part contains the video window. The right part is dedicated to the
presentation of multimedia information.
3.2
Information about Exhibits
The above described concept (and initial implementation) of the user interface has
influenced the compilation of multimedia information. In the following, we describe the
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data collected for each of the three museums and we give a few sample examples. The
complete site information is available on a CD-ROM. The structure of the data collection
is also described in this section.
3.2.1 Foundation of the Hellenic World
The exhibition in FHW’s workplace (see Figure 6) contains 22 showcases (exhibits). For
each of the exhibits, an image and a descriptive text are contained. In addition, related
context information is included in form of short texts and images relevant to the specific
exhibit. For six exhibits, short video clips are also provided. Currently, the database for
the Foundation of the Hellenic World contains 32 descriptive texts, 71 JPG-images, 10
video clips and 1 sound file. The music contained in the sound file has been composed
especially for the exhibition. It can be played-back for all the exhibits, but especially in
combination with the video clips, which mainly show dances inspired by the exhibits.
Figures 10 and 11 constitute a sample example of the visual and textual information
associated with exhibit 2.
Figure 10 Images associated to exhibit 2 in the Foundation of the Hellenic World.
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Mycenaean dress
Textiles and dresses of the Mycenaean Age are clearly influenced by the weaving and the costumes
of minoan Crete. Mycenaean dresses seem though generally simpler and more conservative.
Mycenaean female costume looks nearly the same as the minoan, as seen in women representations
on mycenaean wall paintings (frescoes). These combined in the same way the open bodice with the
decorative bands, the long dress and the apron. Parallely the long wide hiton of the
anthropomorphic figurines underlines a contemporary but quite different trend. Gradually the
impressive dresses of the minoan type was restricted in the cerebrian festivals (?) social events or
they were only wore by the priests and the members of the upper classes.
The differences between minoan and mycenaean clothes are more clearly visible in the male dress.
Mycenaeans wore a short-sleeved hiton, long up to the knees, consisted of two parts. The edges
were decorated with woven bands in various colours. Priests wore a very similar but long chiton,
which reached the foottoes.
Figure 11 Textual information related to exhibit 2 in the Foundation of the Hellenic
World.
The following Table 1 summarizes the multimedia information (data) for the exhibits of
the Foundation of the Hellenic World, sorted according to the order of the spots depicted
in Figure 6.
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Table 1. Multimedia information for the exhibits of the Foundation of the Hellenic
World.
Spot
Title
# Texts
# Images
# Videos
1
Introduction
3
4
2
2
Prehistoric period
3
6
1
3
Warp-weighted loom
1
3
4
Archaic-classical period
4
7
5
Hellenistic period
1
2
6
Roman period
1
3
7
Horizontal seating loom
1
1
8
Byzantine period
2
6
9
Byzantine imperial costume
1
3
10
Byzantine aristocrats
1
3
11
Ottoman period
1
1
12
Costumes in towns
1
2
13
Costumes in rural areas
2
5
14
Bridal dress
1
2
15
Age of Greek revolution
1
4
16
Age of Kapodistrias
1
2
2
2
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17
Reign of Otto
1
3
18
Reign of George
1
2
19
Sewing-machine
1
2
20
Local costumes
1
2
21
Skopelos female costume
1
3
2
22
Asia Minor costumes
2
5
1
Sound Especially composed music for all the exhibits
3.2.2 The Deutsches Museum Bonn
Within the Deutsches Museum Bonn, TOURBOT’s area of operation assumes part of the
exhibition containing 26 exhibits (see Figure 7), several of them showing items related to
Nobel prizes. For all these exhibits, the site information database contains again
explanatory texts and images. For each exhibit, there are at least two different pieces of
text, one describing the exhibit directly and the other(s) putting the exhibit into a social
and/or historical context. One example is the “ion cage”, the relevant information of
which is shown in Figures 12 and 13. In addition to images and text, the site information
for the Deutsches Museum Bonn contains 7 QuickTimeVR’s of different locations within
the exhibition; they will be included in the Web interface to allow the user to get an
initial impression of the exhibition prior to controlling the robot.
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Figure 12 Paul’s ion cage; two images for the exhibit at showcase 1 of the Deutsches
Museum Bonn
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The Paul ion cage
The ion cage holds charged particles (ions or electrons) captive within tight bounds. Suitable DC and AC
electric fields, applied between the specially shaped walls, restrict the particles to the centre of the field
without touching the walls of the cage. Since the particles are free and undisturbed, physicists can
measure their properties to an extremely high accuracy. Chemists can detect just a few atomic or
molecular ions, and distinguish between them. Hans Dehmelt and his colleagues in Seattle/USA even
succeeded in trapping and holding a single electron for months in a similar electromagnetic cage –
invented by F.M. Penning in the 1930s. Bildunterschrift: Ion-catcher. Wolfgang Paul after his
nomination for the Nobel physics prize was made known in 1989.
A prizeworthy by-product
Wolfgang Paul evolved the principle of a cage for electrons and ions in the mid-fifties, while preparing
for the construction of the 500-MeV »strongly focused« synchrotron. The ion cage was effectively a byproduct of this research. Klaus Berkling built the first operational electron cage in 1957, while Erhard
Fischer produced the first ion cage in 1959. Klaus Berkling and Erhard Fischer were pupils of Wolfgang
Paul. The Paul method of trapping minute particles of matter, the better one to investigate and
differentiate them, was developed for pure research in physics. The method now finds extensive practical
applications in chemistry and environmental research.
Ioncatcher
Wolfgang Paul (1913-1993) was active for nearly thirty years as Professor and Director of the Faculty of
Physics at the University of Bonn. He held leading positions in the European nuclear research institutes
CERN and DESY. In recognition of his discoveries leading to the development of the ion cage, he was
awarded the 1989 Nobel physics prize, together with Hans Dehmelt and Norman Ramsey. The model
illustrating the functional principle of the ion trap was used by Wolfgang Paul as a demonstration in his
Nobel lecture.
Figure 13 Textual material related to Paul’s ion cage.
Table 2 summarizes the multimedia information (data) for the exhibits of the Deutsches
Museum Bonn.
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Table 2. Multimedia information for the exhibits of the Deutsches Museum Bonn.
Spot
Title
# Texts
# Images
1
The Paul ion cage
3
7
2
The visible ion
3
3
3
Storage-ring ion cage
3
1
4
ESQUIRE mass spectrometer
3
1
5
6-MeV betatron
3
1
6
Mössbauer effect
3
4
7
MIMOS
3
3
8
Mössbauer archaeology
3
4
9
Junghans watches
3
7
10
The ion cage as a time standard
3
1
11
CS1 atomic clock
3
10
12
The quantum Hall effect
3
3
13
Cryostat
3
1
14
Patch clamp measurement
3
2
15
Antibody production
3
5
16
Elements 107 to 112
3
3
17
Dibenzenechromium
3
4
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18
Fullerene generator
3
2
19
The dye laser
3
4
20
Gas chromatography
3
1
21
DNA bases made visible
3
6
22
LAURON
3
3
23
Vom Ei zur Gestalt
3
3
24
Revealing structures
3
2
25
Evolution machine
3
1
26
Relaxation methods
3
4
7 QuickTime VR’s of the Exhibition
3.2.3 The Byzantine and Christian Museum of Athens
The Byzantine and Christian Museum of Athens is famous for its collection of icons. The
part of the museum, where the TOURBOT system will operate, displays 32 different
icons. The information database contains 38 photos of these exhibits and descriptive
texts. Figure 14 shows three images, two for exhibit 23 and one for exhibit 31 (see Figure
8), and Figure 15 gives a typical example of a descriptive text.
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Figure 14 Photos of icons exhibited in the Byzantine and Christian Museum of Athens.
Left: Both sides of double-sided icon (exhibit 23), right: icon Ierousalim (exhibit 31).
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Double sided icon
St. J. and her children / Crucifixion
Second half 14th c.
The saint is depicted standing and in frontal pose between two young men, also standing and frontal.
She holds a martyr´s cross in her right hand and touches the hair of a smaller boy, standing en face
in front of her, with her left. The three male figures also hold the martyr´s cross.
There are no inscriptions accompanying the representation and it was identified through comparison with
an iconographic parallel for it in the wall-paintings of the narthex in the church of the Hagioi Anargyroi
at Kastoria. The representation there includes all the figures in our identified by nominative inscriptions:
Η ΑΓΙΑ ΙΕΡΟΥCΑΛΗΜ [Ο ΑΓΙΟC] CΕΚΕΝΔΟC and Ο ΑΓΙΟC CΕΚΕΝΔΙΚΟC. Hierousalem
(Jerusalem) is a local saint of Veroia, who was martyred in that city, together with her sons, Sekendos,
Sekendinos and Kegoros.
The fact that the icon comes from Veroia, surely validates this identification, while its rare subject, unique
so far in icon-painting, and careful rendering make it a valuable work. It was attributed to a workshop in
Veroia and dated to the second half of the fourteenth century. It differs from the other icons known from
Veroia in the glossier colours on the flesh and the more careful drapery of the garments, which are also
rendered in lustrous, blended tones.
Figure 15 Textual description of exhibit 31 of the Byzantine and Christian Museum of
Athens.
Table 3 summarizes the multimedia information (data) for the exhibits of the Byzantine
and Christian Museum of Athens.
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Table 3. Multimedia information for the exhibits of the Byzantine and Christian
Museum of Athens.
Spot
Title
# Texts
# Images
1
The Nativity Royal Doors
2
2
2
Theophanis: Christ The Vine
1
1
3
Saint Marina
1
1
4
Frangos Katelanos:St Demetrius
1
1
5
Kralena
1
1
6
Emmanuel Lambardos: St . Nicholas
1
1
7
Three Hierarchs
1
1
8
Deesis
1
1
9
Nativity
1
1
10
Double-sided icon:
A. Christ Pantocrator / B. Cross
1
1
11
Archangel Michael
1
1
12
Double-sided icon:
A. Virgin Hodegetria and Dodekaorton /
B. Hetoimasia of the throne
1
1
13
Ascension
1
1
14
J ( esus ) H( ominum) S( alvator)
1
1
15
Holy Trinity
1
1
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16
Michael Damascenos:
The Crucifixion of St . Andreas /
The Holy Communion
1
2
17
The Kardiotissa
1
1
18
The Forty Martyrs /
Ioannis Apakas:
The Descent from the Cross
Angelos: The Presentation of the Virgin Mary
1
2
1
1
20
St Antonios and scenes of his life /
St Nicholas with scenes from his life and his
miracles
1
2
21
Angelos: Saint John the Baptist
1
1
22
St Theodore Teron slaying the Dragon
1
1
23
1
2
24
Double-sided icon: A. Female saint
B. Saint Zosimas and Mary of Egypt
Triptych
1
1
25
Life of the Virgin and Virgin of the Passion
1
1
26
The Crucifixion
1
1
27
Saint Catherine
1
1
28
St Eleftherios
Frangos Katelanos: St Demetrius
2
2
29
Virgin " The Galaktotrofousa"
1
1
30
St George and Deesis
1
1
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31
Saint Jerusalem and her children Crucifixion
1
1
32
The Dormition of Ephraim the Syrian
1
1
3.2.4 The Data Collection
The complete collection of all the site information is contained on a CD-ROM. The
contents of this CD-ROM will be readily usable by the TOURBOT system for demos at
the corresponding user sites. The material (data) is structured using the following
convention on the structure of the directory tree:

one directory for each museum (FHW, MUSBON, BYZMUS),

one sub-directory for each showcase/exhibit, following the numbering that appears on
the user interaction map,

sub-directories for images, text, sound, and video.
The items of the collection are not connected via hyperlinks. For the sake of flexibility,
the TOURBOT system will compile the information into web pages and pages for the onboard interface on-line.
4
Publications
[1] S. Thrun, W. Burgard and D. Fox. A real-time algorithm for mobile robot mapping
with applications to multi-robot and 3D mapping. In Proc. of the IEEE International
Conference on Robotics & Automation (ICRA), 2000.
[2] D. Schulz, W. Burgard, D. Fox, S. Thrun and A.B. Cremers. Web Interfaces for
Mobile Robots in Public Places. In IEEE Robotics & Autom. Magazine, 1(7), 2000.
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[3] P. Trahanias et al. “TOURBOT: Interactive Museum Telepresence through Robotic
Avatars,” In 9th Intl. World Wide Web Conf. Culture Track, Session A-2: Museums
on the Web - Case Study, Organizer: A.M. Ronchi, Amsterdam, May 15-19, 2000.
[4] D. Schulz, W. Burgard and A.B. Cremers. State Estimation Techniques for 3D
Visualizations of Web-based Tele-operated Mobile Robots. Künstliche Intelligenz
(KI), 4, 2000.
[5] D. Schulz and W. Burgard. Probabilistic State Estimation of Dynamic Objects with a
Moving Mobile Robot. Journal of Robotics and Automation, Elsevier, to appear.
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