Projection-Based Models for Capturing
Human Concepts of Motions

UniversitätBremen

Yohei Kurata and Hui Shi
SFB/TR 8 Spatial Cognition, Universität Bremen / {ykurata, shi}@informatik.uni-bremen.de

What are Projection-Based Models?

Existing Projection-Based Models

relatum
referent

Viewer(optional)

Relatum

My son is standingat the right backof a tree

viewerClass

Referent

Projection-based models [1] are spatial models that projects a frame ofspatial reference [2] onto a space, by which the arrangement of two or
three spatial objects are distinguished

CodeNameSingle Cross [3]relativePPP

PrP1-8

Double Cross in [3]relative

P

P×2

PrP1-82

Double Cross in [4]intrinsic

P LSD –PiLSD 3-12

Dipole Calculus [5, 6]

intrinsic

LSD ×2– LSDiLSD 0-22

Models of Cardinal
Directions [7]absolute

Arbitrary

Arbitrary–AaA1-8Ternary Point Configuration Calculus (TPCC) [8]relative

PP

P

PrP1-24

Bipartite Arrangements [9]intrinsic

LSD LSD – LSDiLSD 3-12

absolute

PP–

PaP1-4nintrinsic

PD×2–

PDiPD 1-n2intrinsic

P–

PiPD 1-nintrinsic

P LSD –PiLSD m-nFrame

Model

Shape

frame of spatial reference

Projection-Based Models and Motion Concepts
Two types of projection-based models are potentially useful for modelinghuman concepts/expressions of movement

Point-Referent Models
I walk to
the front of
the church

DLine-Relatum Models
Star Calculus [10]I passthe churchon the left

relatum

referent

referent
relatum,

Oriented Point Relation
Algebra (OPRA) [11],,Ego Orientation [12]pass … on the left/right, go along,
go toward, go across, go into, …

For systematization, projection-models are given the code names:

XyZm-ndResearch Goal

Number of units thatcomposes one relation

Referent
Frame class

To systematize the existing projection-based models andidentify the missing models that are potentially useful formodeling motion concepts
Drive me towardthat door

In our perspective, this study consolidates a foundation of
our project toward the natural dialogue-based interface ofintelligent semi-autonomous wheelchairs

1. Geometric types of the referent / relatum

Line(L)

Straight DirectedLine (LSD)

Number of fields
on/around the referent

Relatum

What Models Are Not Yet Developed?
Point-Referent Models (PyZm-nd)

Systematization Criteria

Directed Point(PD)…

PD

Path-centric motion concepts

go to the front/right/left of,
go behind, go to the north of, …

Point(P)…
…

Orientation Calculi [12]Goal-oriented motion concepts

…

√ PaP

√ PaL

√ PaR (⊂ √ AaA)

√ PiPD√ PiLSD× PrRD√ PrP
PP× PrL
PL

× PrR
PR

These three are potentially useful for capturing goal-oriented
motion concepts when the landmark is linear or region-like(e.g., go to the front of the door, go behind the table)

Region(R)Directed Region(RD)

DLine-Relatum Models (XiLSDm-nd)√ PiLSD× LiLSD (⊃ √ LSDiLSD)

× RiLSD

2. Frame class distinguished by its orientation factor [2]Absolute Frame

Intrinsic Frame

Relative Frame

These two are potentially useful for capturing path-centric
motion concepts when the landmark is linear or region-like(e.g., go toward the door, go across the rug)

BremenBased on this idea, we are currently developing a seriesof models that belong to RiLSD and applying them tothe modeling of a number of motion concepts [13]FreiburgReferences

3. Frame shape[1] Frank (1996) Qualitative Spatial Reasoning: Cardinal Directions as anExample. International Journal of Geographical Information Science 10,262-290[2] Levinson (1996) Language and Space. Annual Review of Anthropology 25,353-382[3] Freksa (1992) Using Orientation Information for Qualitative Spatial
Reasoning. In: International Conference GIS, LNCS 639, 162-178.
[4] Zimmermann & Freksa (1996) Qualitative Spatial Reasoning Using
Orientation, Distance, and Path Knowledge. Applied Intelligence 6, 49-58[5] Schlieder (1995) Reasoning about Ordering . In: COSIT'95, LNCS 988,341-349.
[6] Moratz, Renz, & Wolter (2000) Qualitative Spatial Reasoning about LineSegments. In: European Conference on Artificial Intelligence, 234-238[7] Goyal & Egenhofer (2000) Consistent Queries over Cardinal Directions
across Different Levels of Detail. In: 11th International Workshop on
Database and Expert Systems Applications, 876-880[8] Moratz, Nebel, & Freksa (2003) Qualitative Spatial Reasoning about
Relative Position: The Tradeoff between Strong Formal Properties andSuccessful Reasoning about Route Graphs In: Spatial Cognition III, LNAI,2685, 385-400.
[9] Gottfried (2004) Reasoning about Intervals in Two Dimensions. In: IEEEInternational Conference on Systems, Man and Cybernetics, 5324-5332[10] Renz & Mitra (2004) Qualitative Direction Calculi with Arbitrary Granularity.
In: 8th Pacific Rim International Conference on Artificial Intelligence, 65-74[11] Moratz, Dylla, & Frommberger (2005) A Relative Orientation Algebra with
Adjustable Granularity. In: Workshop on Agents in Real-Time and Dynamic
Environments[12] Krieg-Brückner & Shi (2006) Orientation Calculi and Route Graphs:
Towards Semantic Representations for Route Descriptions. In:
GIScience’06, LNCS 4197, 234-250.
[13] Kurata & Shi (2008) Interpreting Motion Expressions in Route Instructions
Using Two Projection-Based Spatial Models. To appear in: KI 2008, LNAI