Synthesis of Universal Safety Controllers

2025-01-30

AI Summary

Traditional logic controller synthesis relies on complete plant models, resulting in poor scalability, limited adaptability, and opaque control strategies. Method: This paper proposes a model-free, oracle-driven framework for synthesizing universal safety controllers. It constructs a game graph directly from temporal logic specifications, annotates states with oracle variables to encode environment assumptions, and synthesizes an oracle-augmented universal controller. An online adaptation algorithm enables safe, real-time control and dynamic reconfiguration for any implementable plant. Contribution/Results: The approach eliminates dependence on explicit plant modeling. Evaluated on the prototype tool UNICON, it achieves substantial reductions in memory and runtime overhead, supports cross-plant controller reuse, guarantees global safety, and enhances both interpretability and scalability of synthesized controllers.

Technology Category

• Natural Language Processing: Safety and Robustness
• Planning, Routing, and Scheduling: Model-Based Reasoning
• Reasoning under Uncertainty: Sequential Decision Making

Application Category

• Economics, Online Markets and Human Computation: Cost models of using LLMs in production systems
• Graph Algorithms and Modeling for the Web: Foundation models and LLMs for Web-related graphs
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs

Abstract

The goal of logical controller synthesis is to automatically compute a control strategy that regulates the discrete, event-driven behavior of a given plant s.t. a temporal logic specification holds over all remaining traces. Standard approaches to this problem construct a two-player game by composing a given complete plant model and the logical specification and applying standard algorithmic techniques to extract a control strategy. However, due to the often enormous state space of a complete plant model, this process can become computationally infeasible. In this paper, we introduce a novel synthesis approach that constructs a universal controller derived solely from the game obtained by the standard translation of the logical specification. The universal controller's moves are annotated with prophecies - predictions about the plant's behavior that ensure the move is safe. By evaluating these prophecies, the universal controller can be adapted to any plant over which the synthesis problem is realizable. This approach offers several key benefits, including enhanced scalability with respect to the plant's size, adaptability to changes in the plant, and improved explainability of the resulting control strategy. We also present encouraging experimental results obtained with our prototype tool, UNICON.

Problem

• Logic Controller Synthesis
• Safety Assurance
• Complex Systems

Innovation

• Logic Controller Synthesis
• Predictive Control
• UNICON Validation