ACIES: A Self-Evolving Agentic Contract-Based Framework for Cyber-Physical System Control Synthesis

Yifeng Xiao, Zhiyu Ni, Dinghong Song, Mi Zhou, Pierluigi Nuzzo


Abstract
Large language models (LLMs) are increasingly being explored in cyber-physical system design as a promising tool to facilitate the conversion of natural-language requirements into formal specifications, and the generation of plans and controllers that provably satisfy them. Existing LLM-based pipelines, however, mostly validate the designed controllers by simulation, and carry no mechanism for improving their outcomes from past designs. We present ACIES, a self-evolving agentic contract-based framework for cyber-physical system control synthesis. Given a set of system requirements, ACIES automatically generates a control architecture that realizes the requirements using a sequence of synthesis episodes. Within each episode, a Translator agent formalizes the system requirements into temporal logic, and a Decomposer agent structures them into a system-level contract and proposes a decomposition into component-level contracts that can be independently implemented. A formal verification step is then integrated in the decomposition loop to check whether the component-level contracts are consistent, compatible, and provide a correct refinement of the system-level contract. Each failed check, at the verification or implementation step, returns a diagnostic signal that drives automated contract repair at the system or the component level. Across episodes, a Summarizer agent distills verification outcomes into reusable lessons stored in a memory. Evaluation results on five control synthesis tasks with eight LLM backbones show that the formalized system requirements are successfully decomposed and mapped to a synthesizable control architecture that realizes them, while self-evolution reduces the Decomposer token consumption by up to 65% and the end-to-end synthesis latency by up to 62%.
Anthology ID:
2026.realm-1.36
Volume:
Proceedings of the Second Workshop for REsearch on Agent Language Models (REALM 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Ehsan Kamalloo, Nicolas Gontier, Nikolai Rozanov, Maryam Hashemzadeh, Akhil Arora
Venues:
REALM | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
541–550
Language:
URL:
https://aclanthology.org/2026.realm-1.36/
DOI:
Bibkey:
Cite (ACL):
Yifeng Xiao, Zhiyu Ni, Dinghong Song, Mi Zhou, and Pierluigi Nuzzo. 2026. ACIES: A Self-Evolving Agentic Contract-Based Framework for Cyber-Physical System Control Synthesis. In Proceedings of the Second Workshop for REsearch on Agent Language Models (REALM 2026), pages 541–550, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ACIES: A Self-Evolving Agentic Contract-Based Framework for Cyber-Physical System Control Synthesis (Xiao et al., REALM 2026)
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PDF:
https://aclanthology.org/2026.realm-1.36.pdf