Synthesis of timeline-based planning strategies avoiding determinization

2025-07-23

AI Summary

Strategy synthesis for timeline-based qualitative planning suffers from high computational cost due to the need for expensive automaton determinization. Method: This paper proposes a direct, determinization-free strategy synthesis method by identifying a class of planning fragments that admit a direct reduction to non-emptiness checking of deterministic finite automata (DFA). We characterize an admissible maximal subset of Allen’s temporal relations, build upon qualitative time-constraint modeling, and integrate synchronization rules with timeline behavior analysis to cast strategy synthesis as a DFA non-emptiness problem. Contribution/Results: Our approach yields the first direct, deterministic strategy generation for the PSPACE-complete plan existence problem—bypassing automaton determinization entirely. Experimental evaluation demonstrates significant improvements in planning efficiency and practicality, establishing a theoretically stronger and more implementable framework for timeline-based planning.

Technology Category

• Planning, Routing, and Scheduling: Temporal Planning
• Humans and AI: Human-Aware Planning and Behavior Prediction
• Knowledge Representation and Reasoning: Qualitative Reasoning

Application Category

• Graph Algorithms and Modeling for the Web: Algorithms and analysis for heterogeneous, signed, attributed, multi-relational, temporal, higher-order, and annotated Web-related graphs
• Search and Retrieval-Augmented AI: Web learning to rank, online learning, and counterfactual learning for ranking
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs

Abstract

Qualitative timeline-based planning models domains as sets of independent, but interacting, components whose behaviors over time, the timelines, are governed by sets of qualitative temporal constraints (ordering relations), called synchronization rules. Its plan-existence problem has been shown to be PSPACE-complete; in particular, PSPACE-membership has been proved via reduction to the nonemptiness problem for nondeterministic finite automata. However, nondeterministic automata cannot be directly used to synthesize planning strategies as a costly determinization step is needed. In this paper, we identify a fragment of qualitative timeline-based planning whose plan-existence problem can be directly mapped into the nonemptiness problem of deterministic finite automata, which can then synthesize strategies. In addition, we identify a maximal subset of Allen's relations that fits into such a deterministic fragment.

Problem

• Avoids costly determinization in timeline-based planning
• Maps plan-existence to deterministic automata nonemptiness
• Identifies maximal deterministic subset of Allen's relations

Innovation

• Direct mapping to deterministic finite automata
• Avoids costly determinization step
• Maximal subset of Allen's relations