@techreport{R-94-21,
PSURL = {/publications/cgi-bin/tr-fetch.pl?r-94-21+ps},
ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-94-21+abstr},
ABSTRACT = {The problem of designing reactive autonomous systems has been the
subject of much attention in recent years.  The research has focused
on designing systems which would possess the following attributes:
1. reactivity, in order to allow the system to cope with unpredictable
changes in the dynamic environment while performing its mission;
2. robustness, meaning the ability to function in a variety of
situations, including failure of some of its subsystems;
3. selectivity of attention, in order to effectively use existing
resources of the system, such as computing power, or sensory
equipment; 
4. ability to pursue goals either defined by the designer, or by the
system itself.

One can distinguish several approaches to this problem.  One of them
is called ``behaviour-based'', because behaviour is the basic
structure used for specifying control for an autonomous system.
Another one is based on layered control architecture, where usually
each layer has its own, well-defined task(s) to perform, often some
software tools supporting implementation of those tasks, and some
appropriate mechanism for passing control between the layers (or
distributing it among them).

Those two approaches are usually opposed to each other:
``Behaviourists'' claim that a rigid architecture requires excessive
computational power and enforce too many constraints on the actual
design and implementation.  The other group claims that behaviour-based
approach is unsuitable for applications requiring either sophisticated
control algorithms, or symbolic reasoning (as e.g. planning)
procedures, or both.  Both criticisms are to some extent justified.

In this paper we present an approach to implementing behaviour-based
control using a three-layered architecture. In this way we intend to
combine the advantages of both approaches.
},
TITLE = {On Implementing Behaviours Using a three-layered Architecture},
AUTHOR = {Jacek Malec},
EMAIL = {jacma@ida.liu.se},
YEAR = {1994},
NUMBER = {R-94-21},
INSTITUTION = ida,
ADDRESS = idaaddr,
IDANR = {LiTH-IDA-R-94-21},
NOTE = {Accepted to Intelligent Robotic Systems'94, Grenoble, France, 11-15 July 1994}