This master's thesis document outlines the development of a dialog-based pedestrian navigation system. It describes the objective to create an interface between a dialog system and a navigation application. Details are provided on the equipment used, experimental setup, an example dialog, landmarks used for navigation, and an adjacency matrix model. It summarizes tests conducted and outlines future work integrating the developed positioning system with a dialog system.

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Presentation of Master Thesis
Development of a Dialog-based Pedestrian
Navigation System
Master Thesis Topic
M.Sc. Student : Aykut Icoez
Supervisor : Dr. Michael Angermann

2. 2
Content
• Objective
• Information about Pedestrians
• Equipment used and Experimental Setup
• Photos of Equipment and Running Application
• Overview of a Dialog System
• Main Parts of a Dialog -with an example-
• Landmarks
• Availability and Visibility : criteria
• Dijkstra’s Algorithm: shortest path
• Sequence of Events in a general application
• Tests and Results
• Outlook

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Objective
Navigation
System
Dialog
SystemInterface
Main part to develop in this work Preparation for further work
Subject application : Navigation system for pedestrians
Two black boxes : The dialog system and the application
Interface : Interaction of both according to requirements

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Background Information about Pedestrians
• Characteristics of Pedestrian Movement:
– Movement Freedom
• Principally all ways free (streets + footpaths)
• Not bounded to certain paths
– Speed
• 5 km/h (1.5 m/s)
– Field of vision
• Orientation in movement direction
• Principally +/- 180 Deg. in line of sight
– Enough time to observe/sense surrounding environment
• Guidance of Pedestrians:
– Requires personalization due to the huge variety of different user demands
– Must be subdivided into groups according to user tasks and information needs
• Pedestrian types:
– tourist, business traveler, resident, disabled person
• Most appropriate type of route - Routing:
– shortest distance, least time, fewest turns, one with most point of interests (POI)

5. 5
Equipment Used
Laptop
GPS Device
UMTS-GPRS CardBlueetooth Device
Compass

6. 6
Backpack Arrangement for Field Tests
Side View Back View

7. 7
Experimental Setup Diagram

8. 8
Photo of Running Application on Laptop

9. 9
View of the Pedestrian Representation
Inputs: Position (GPS) and Direction of View (Compass)
Green dot: Pedestrian (user)

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Overview of a Dialog System
• Speech Recognizer : produces a word lattice (sequence of words)
• Semantic Parser : determines the meaning of the query, produces best interpretation
(extracting a meaning)
• Dialog Manager : resolve ambiguities, clarifies with user, builds database queries
(initiating system actions)
• Database interface : uses the meaning representation and to generate a database
query & to access database
• Response generator : presents the interaction result in the form of text, speech,
tables or graphics.

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Main Parts of a Dialog
• First Part:
– Aim : Target spefication (e.g.: go, reach to…)
– Direction : From the user to the application
• Second Part:
– Aim : Orientation (e.g.: stand with your back to, turn around…)
– Direction : From the application to the user
• Third Part:
– Aim : Moving (e.g.: walk, go, continue straight/towards, across…)
– Direction : From the application to the user
• Fourth Part:
– Aim : Arrival (e.g.:arrive at, reach to, find…)
– Direction : From the application to the user

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1. Part : Target spefication
Computer: Where do you want to go?
User : I want to go to <library>. (<casino> or <canteen>)
Computer: To <library>?
User : <Yes>/<No>
2. Part : Orientation
Computer: Stand with your back to Institute <A>. (<B>, <C>, <D>)
Computer: Turn <left> around yourself. (<right>)
3. Part : Moving
Computer: Walk (<…> meters) straight till you reach Institute <A> at your <left>.
Computer: Do you see Institute <A> at your <left>?
User : <Yes>/<No>
Computer: Turn <left>. Walk (<…> meters) straight till you reach <casino> at your <right>.
4. Part : Arrival
Computer: You have arrived at <library>.
Example of a Dialog
Landmarks : Institute <A> or <B> or <C> or <D>
Alternatives : are shown with <…>.
Method used : System-directed, system asks all the questions, user is passive.

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Landmarks
• Definition:
– Every orientation point in the range of movement
– Used as a reference
• Features:
– Special visual characteristics (noticeable difference to neighborhood)
– A special function/meaning or central state/location
• Reasonable locations in practice:
– Along the path / at decision points / far away, but visible
• Possible types:
– Architecture (towers, main entrance, monuments, columns, bridges)
– Commercial activity (newspaper kiosk, fish market)
– Buildings (institutions, schools, fire stations, churches)
– Street-network (crossroads, junctions)
– Water features (rivers, channels)
– Various (telephone booths, parking lots)
Note: Colorful ones show the ones chosen at the DLR site.

14. Bird view of DLR Site

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Allocation Plan of DLR Site

16. 16
Illustration of Landmarks on Map

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Graphical View of Landmarks at DLR Site
Total number of chosen landmarks: 20
Two way
One way

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Photos from Landmark 1 and 2
At Landmark 1 (LM1) At Landmark 1 (LM1)
At Landmark 2 (LM2) At Landmark 2 (LM2)
LM2
LM20 LM19
LM1
LM3

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Availability and Visibility
• Two criteria used to identify relation between different landmarks
• Availability:
– A route connects the source LM to the next LM lying in the neighborhood.
– There is no other LM lying in-between.
• Visibility:
– A human can see the next LM as he stands at the source LM.
• Examples at DLR site:
– Available / Visible (A / V) : LM1 – LM2
• Connecting route without any other LM on the way and no obstacle in-between
– Not available / Visible(NA / V) : LM1 – LM19
• Connecting route with another LM (number 20) on the way and no obstacle in-between
– Available / Not visible(A / NV) : LM2 – LM8
• Connecting route, however obstacle blocking (Building 110)
– Not available / Not visible (NA / NV) : LM1 – LM8
• No direct route connection and obstacles blocking line of sight

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Formation of Adjacency Matrix
…NVVVLM 19
NV…VNVLM 8
VNV…VLM 2
VNVV…LM 1
LM 19LM 8LM 2LM 1
…NANANALM 19
NA…ANALM 8
NAA…ALM 2
NANAA…LM 1
LM 19LM 8LM 2LM 1
…NA / NVNA / VNA / VLM 19
NA / NV…A / VNA / NVLM 8
NA / VA / NV…A / VLM 2
NA / VNA / NVA / V…LM 1
LM 19LM 8LM 2LM 1
Visibility Matrix
Availability Matrix
Adjacency Matrix
* =
• Availability matrix is symmetric.
• Visibility Matrix and Adjacency Matrix (A.M.) are asymmetric.

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…A / V A / VA / V NA / VA / VLM 20
A / V…A / NV NA / VNA / VLM 19
A / NV…A / V LM 18
A / V A / V…A / V LM 17
A / V A / V…A / V LM 16
A / V…A / VA / V A / NV LM 15
A / V…A / NV A / NVA / NV LM 14
A / VA / NV…A / V LM 13
A / V…A / V A / NVLM 12
A / V…A / V A / VA / NVLM 11
A / NV A / V…A / V LM 10
A / NVA / NV A / V…A / NV A / NV LM 9
A / NV…A / NV A / NVA / NVA / V LM 8
A / NV…A / V LM 7
A / V…A / NVA / V LM 6
A / NV…A / V LM 5
A / NVA / NV A / VA / V…A / V LM 4
A / NV A / V…A / V LM 3
NA / VNA / V A / NV A / V…A / VLM 2
A / VNA / V A / NVA / NV A / V…LM 1
LM
20
LM
19
LM
18
LM
17
LM
16
LM
15
LM
14
LM
13
LM
12
LM
11
LM
10
LM 9LM 8LM 7LM 6LM 5LM 4LM 3LM 2LM 1
Adjacency Matrix of Landmarks at DLR
NA / NVA: available, V: visible, NA: not available, NV: not visible

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Matrix Flow Diagram
…0 / 00 / 10 / 1LM 19
0 / 0…1 / 10 / 0LM 8
0 / 11 / 0…1 / 1LM 2
0 / 10 / 01 / 1…LM 1
LM 19LM 8LM 2LM 1
…000LM 19
0…10LM 8
00…1LM 2
001…LM 1
LM 19LM 8LM 2LM 1
0infiniteinfiniteinfiniteLM 19
infinite0430infiniteLM 8
infiniteinfinite092LM 2
infiniteinfinite920LM 1
LM 19LM 8LM 2LM 1
Double Logic Adjacency Matrix
(conversion of A.M. to logic)
Single Logic Adjacency Matrix
(AND operation executed)
Routing Matrix
(distances added)

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Dijkstra’s Algorithm
• Input: Routing matrix
• Purpose:
– To find the shortest paths from a single source vertex to all
other vertices in a weighted, directed graph
• Structure:
– Begins at a specific vertex and extends outward within the
graph, until all vertices have been reached.
– Stores total distance from a source vertex to the current vertex
• Status in Our System:
– Implemented and tested succesfully, however not integrated yet

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Situation-Dependent Route Finding

25. 25
Sequence of Events
of the Overall System

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Tests and Results
• WoZ experiments were executed with an experienced
and another unexperienced user with success.
– WoZ: The user, without being aware, in interaction with
the administrator who simulates the system
• Corrections and fine-tuning were made considering
landmark positions and their suitability.
• Targeted Navigation Application to interact with a
future Dialogue System is obtained.

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Outlook
• A positioning system is developed and available that is able to
guide a user to reach his destination via the shortest path.
• As a prediction, possible works in future could include the
following:
– The tests can be carried out and extended to a real life
situation by starting at the Landsberg testbed of DLR.
– An appropriate Dialog Strategy could be developed and
used with the Application.
– A Dialog System (possibly with an interface) developed
according to requirements could be implemented with its
main parts interacting with the Navigation Application .

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