lansky@VENICE.AI.SRI.COM.UUCP (06/11/87)
EXECUTING UNIVERSAL PLANS:
EMERGENT GOAL STRUCTURES & THEIR USES
Marcel Schoppers (MARCEL@ADS.COM)
Advanced Decision Systems
11:00 AM, MONDAY, June 15
SRI International, Building E, Room EJ228
``Universal plans'' are designed for execution in unpredictable state spaces,
refusing to over-commit to a specific future course of events, and deliberately
making no assumptions about how situations might follow one another. Instead,
plan synthesis becomes the goal-directed selection of reactions to possible
situations; plans become inherently conditional; and plan execution classifies
the current situation so as to respond with the selected reaction. Consequently
there is no inherent distinction between expected and unexpected events; the
concepts of success & failure are irrelevant for both synthesis and execution;
and "error recovery" needs no special mechanisms beyond those already present
for normal execution.
After introducing the Universal Plan representation, this talk will show how at
any given instant, plan predicates can be interpreted as goals of achievement
or of maintenance, and that this interpretation can be used to reconstruct a
four-fold typing of events (of success, failure, serendipity and sabotage). In
other words, intentions emerge from the interaction of plan with environment
(the environment has a large hand in determining the agent's goals at each
moment), and the notions of success and failure are not primitive but
perceived (relative to the agent's goals).
The Universal Plan representation also indicates precisely which conditions
must be monitored at each instant to enable detection of all events of each
type. Two benefits follow; I will only mention them briefly. First, we can
get complexity estimates for detecting all serendipity and sabotage events,
and can produce informed strategies to alleviate sensing costs. Second, the
goal structure at each moment in time contains all the information required
to choose an appropriate action, thus facilitating incremental synthesis.
VISITORS: Please arrive 5 minutes early so that you can be escorted up
from the E-building receptionist's desk. Thanks!