Date of Award

6-2026

Document Type

Thesis

Degree Name

Master of Science in Astronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

David W. Meyer, PhD

Abstract

Modern defense systems continue to grow in complexity, placing increasing pressure on engineering workflows to be faster and more adaptable. While Model-Based Systems Engineering (MBSE) with the emerging SysML v2 standard provides a framework for capturing system behavior, its practical use is often limited by the expertise and time required for manual modeling. This research investigates whether large language models (LLMs) can help overcome that barrier by automatically generating SysML v2 state machines from Guidance, Navigation, and Control (GNC) textual inputs. Three LLM Flowise-based models were developed and evaluated: the Structured Transformation Model (STM), which uses a structured extraction and JSON coding process; the Example-Guided Structured Model (EGSM), which pairs a structured extraction with example-driven generation; and the Example-Guided Contextual Model (EGCM), which applies flexible parameter extractions and example-driven generation with SysMLv2 definitions. Each model was tested using technical documents of three GNC subsystems: an Electro-Optical seeker, an Inertial Stellar Compass, and a Hybrid Navigation System. Outputs were evaluated against ten metrics assessing syntactic correctness, semantic fidelity, and behavioral coherence. Local LLMs between 7b and 14b parameters were prioritized for their customized performance, privacy, and model autonomy, with comparisons made to the larger models GPT-4o and Claude 3.7. Results show that all approaches successfully generated valid, reusable SysML v2 models to different levels of fidelity. Local models, especially those using example-guided strategies, achieved solid performance across most metrics and required minimal correction. These findings demonstrate that LLMs can support automated SysML v2 model generation and significantly reduce the technical burden associated with MBSE, potentially enabling broader adoption in defense-related system development.

AFIT Designator

FY25-AFIT-ENY-MS-J-002

Comments

An embargo was observed for posting this thesis on AFIT Scholar.
Approved for public release, PA case number 88ABW-2025-0544.

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