Contributor:
Nilsson, Mikael;
Kvarnström, Jonas;
Doherty, Patrick
Published:
Association for the Advancement of Artificial Intelligence (AAAI), 2013
Published in:
Proceedings of the International Conference on Automated Planning and Scheduling, 23 (2013), Seite 337-341
Language:
Not determined
DOI:
10.1609/icaps.v23i1.13603
ISSN:
2334-0843;
2334-0835
Origination:
Footnote:
Description:
Simple Temporal Networks with Uncertainty (STNUs) allow the representation of temporal problems where some durations are determined by nature, as is often the case for actions in planning. As such networks are generated it is essential to verify that they are dynamically controllable -- executable regardless of the outcomes of uncontrollable durations -- and to convert them to a dispatchable form. The previously published FastIDC algorithm achieves this incrementally and can therefore be used efficiently during plan construction. In this paper we show that FastIDC is not sound when new constraints are added, sometimes labeling networks as dynamically controllable when they are not. We analyze the algorithm, pinpoint the cause, and show how the algorithm can be modified to correctly detect uncontrollable networks.