A Causal Approach for Modelling Spatial Dynamics∗ A Preliminary Report

We propose a causal approach, involving events identified by their causes and effects, for the modelling of spatial dynamics. The suitability of situation calculus as a high-level formalism for representing and reasoning about spatial dynamics is explored and the causal framework is formalised using the same. A systematic illustration of the manner in which various aspects of axiomatic qualitative spatial calculi may be represented within the proposed causal framework is presented. The main advantage of this approach is that based on the structure and semantics of the calculus, computational tasks such as planning, projection and explanation can be directly exploited. Within the specialised spatial reasoning domain, these translate to spatial planning/re-configuration, simulation and causal explanation (i.e., inferring cause from observations). Furthermore, given the qualitative nature of the spatial theory and the non-monotonic reasoning capability within the formalism, the approach is also better suited at representing human-like abilities of common-sense reasoning with incomplete information. The main hypothesis underlying our approach is that an alternate causal perspective of existing qualitative spatial calculi using high-level tools such as the situation calculus is essential for their utilisation in diverse application domains such as intelligent systems, cognitive robotics and eventbased and Temporal-GIS.