| Abstract: |
Modern cyber-physical systems (CPS) increasingly integrate heterogeneous sensors, actuators, controllers, and services into compositions formed at runtime.
Natural-language (NL) orchestration of such systems is attractive, but unconstrained large language model (LLM) tool use is risky because actions must respect device capabilities, runtime state, and safety constraints.
We present SafeOrchestrate, a reference architecture for runtime-checked, intent-driven CPS orchestration.
Given an NL intent, SafeOrchestrate decomposes it into atomic goals, generates a runtime-checkable specification for each goal, grounds these specifications in discovered device affordances, and gates candidate actions against the runtime state.
For single-action consequents, it also checks each action against the complete grounded specification and any safety constraints before execution.
In our Web of Things (WoT) instantiation, SafeOrchestrate produces Linear Temporal Logic (LTL)-style specifications, grounds them in Thing Description (TD) affordances exposed through the Model Context Protocol (MCP), and enforces satisfiability modulo theories (SMT)-backed guardrails on single-action consequents.
We evaluate this instantiation against a direct LLM-to-MCP baseline on simulated smart home, greenhouse, and industrial automation tasks.
Cross-rule and safety-constraint checks are illustrated separately through a worked example.
SafeOrchestrate achieves 100% required-action accuracy on every task and 100% MCP Execution Similarity (MCP-ES) on all but one, where MCP-ES is 92%.
By contrast, the baseline degrades on multi-device, event-triggered, and ordered tasks, with MCP-ES falling to 13%.
On these tasks, the results suggest that combining LLM-based specification generation with role-aware grounding and runtime constraint checking improves reliability for open CPS orchestration without enriched TD annotations or planning-domain expertise. |