Formalising the Common Sense of a Mobile Robot
Paulo E. Santos

Abstract:
Looking at the history of Artificial Intelligence, often theoretical rigor 
seems inversely proportional to practical applicability. Particularly, in 
the field of robotics, there is a gap between the research on knowledge 
representation and practical robotics. In the present paper, a solution for 
bridging this gap is described and discussed: Shanahan's logical account for 
a mobile robot. Called ``A Logical Account for the Common Sense Informatic 
Situation for a Mobile Robot'', this framework involves the assimilation of 
sensor data, and action planning, through an abduction process on theories 
about actions and change, and space and shape. An extension of the Event 
Calculus is taken as the underlying logical system. Actually, these theories 
are fragments of second-order logic since Circumscription (which is expressed 
in second-order logic) is used to overcome the frame problem. 

However, the solution presented to the frame problem does not cope with all 
of the issues concerned with this problem (since the solution deals only 
with the persistence problem); moreover, due to the lack of an algorithm 
capable of automatically constructing theories about the background knowledge, 
it is impossible to affirm whether the solution presented solves, in a general 
way, the problem for which it is proposed. 

Finally, the analysis of the computational complexity of the framework in 
question made us conclude that, in the general case, its complexity is at 
least complete for the second level of the polynomial hierarchy.