Summary: Logic­Based Subsumption Architecture
Eyal Amir a,1 Pedrito Maynard­Zhang b,2
a Stanford University, Computer Science Department, Stanford, CA 94305­9020, USA
b Miami University, Computer Science & Systems Analysis Department, Oxford, OH
45056, USA
Abstract
We describe a logic­based AI architecture based on Brooks' subsumption architecture. In
this architecture, we axiomatize different layers of control in First­Order Logic (FOL) and
use independent theorem provers to derive each layer's outputs given its inputs. We imple­
ment the subsumption of lower layers by higher layers using nonmonotonic reasoning prin­
ciples. In particular, we use circumscription to make default assumptions in lower layers,
and nonmonotonically retract those assumptions when higher layers draw new conclusions.
We also give formal semantics to our approach. Finally, we describe layers designed for the
task of robot control and a system that we have implemented that uses this architecture for
the control of a Nomad 200 mobile robot.
Our system combines the virtues of using the represent­and­reason paradigm and the
behavioral­decomposition paradigm. It allows multiple goals to be serviced simultaneously
and reactively. It also allows high­level tasks and is tolerant to different changes and elabo­
rations of its knowledge in runtime. Finally, it allows us to give more commonsense knowl­
edge to robots. We report on several experiments that empirically show the feasibility of

Source: Amir, Eyal - Department of Computer Science, University of Illinois at Urbana-Champaign

Collections: Computer Technologies and Information Sciences