Tactical (sentence-level): - Strengthened weak verbs and passive constructions - Improved issue-point positioning (old info first, new info in stress position) - Removed unnecessary hedging phrases - Fixed active/passive voice for clarity Operational (paragraph/section): - Added transition sentences between major subsections - Strengthened flow between State of the Art and Research Approach - Added connecting tissue between continuous controller types - Improved coherence within outcomes section Strategic (document-level): - Made 'what's new' explicit with highlighted innovation statement - Added summary paragraph to State of the Art defining the verification gap - Strengthened connections between sections for Heilmeier alignment - Clarified how the three-layer approach unifies existing tools
82 lines
4.1 KiB
TeX
82 lines
4.1 KiB
TeX
% GOAL PARAGRAPH
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This research develops a methodology for creating autonomous control systems
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with event-driven control laws that guarantee safe and correct behavior.
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% INTRODUCTORY PARAGRAPH Hook
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Nuclear power relies on extensively trained operators who follow detailed
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written procedures to manage reactor control. Operators interpret plant
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conditions and make critical decisions about when to switch between control
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objectives.
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% Gap
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This reliance on human operators creates an economic challenge for
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next-generation nuclear power plants. Small modular reactors face per-megawatt
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staffing costs that significantly exceed those of conventional plants. These
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economic constraints demand autonomous control systems that safely manage
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complex operational sequences with the same assurance as human-operated systems,
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but without constant supervision.
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% APPROACH PARAGRAPH Solution
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We will combine formal methods from computer science with control theory to
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build hybrid control systems that are correct by construction.
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% Rationale
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Hybrid systems use discrete logic to switch between continuous control modes,
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mirroring how operators change control strategies. Existing formal methods
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generate provably correct switching logic but cannot handle continuous dynamics
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during transitions. Traditional control theory verifies continuous behavior but
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lacks tools for proving discrete switching correctness.
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% Hypothesis and Technical Approach
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A three-stage methodology will bridge this gap. First, we translate written
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operating procedures into temporal logic specifications using NASA's Formal
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Requirements Elicitation Tool (FRET). FRET structures requirements into scope,
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condition, component, timing, and response elements, enabling realizability
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checking that identifies conflicts and ambiguities before implementation.
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Second, we synthesize discrete mode switching logic using reactive synthesis to
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generate deterministic automata that are provably correct by construction.
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Third, we develop continuous controllers for each discrete mode using standard
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control theory and reachability analysis. We classify continuous modes based on
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their transition objectives, then employ assume-guarantee contracts and barrier
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certificates to prove that mode transitions occur safely and as the
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deterministic automata specify. Local verification of continuous modes becomes
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possible without global trajectory analysis across the entire hybrid system. An
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Emerson Ovation control system will demonstrate this methodology.
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% Pay-off
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This approach demonstrates that autonomous control can manage complex nuclear
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power operations while maintaining safety guarantees.
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% OUTCOMES PARAGRAPHS
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If this research is successful, we will be able to do the following:
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\begin{enumerate}
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% OUTCOME 1 Title
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\item \textit{Synthesize written procedures into verified control logic.}
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% Strategy
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We will develop a methodology for converting written operating procedures
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into formal specifications. Reactive synthesis tools will then generate
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discrete control logic from these specifications.
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% Outcome
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Control engineers will generate mode-switching controllers from regulatory
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procedures with minimal formal methods expertise, reducing barriers to
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high-assurance control systems.
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% OUTCOME 2 Title
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\item \textit{Verify continuous control behavior across mode transitions.}
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% Strategy
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Reachability analysis will ensure continuous control modes satisfy discrete
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transition requirements.
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% Outcome
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Engineers will design continuous controllers using standard practices while
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ensuring system correctness, proving that mode transitions occur safely at
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the right times.
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% OUTCOME 3 Title
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\item \textit{Demonstrate autonomous reactor startup control with safety
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guarantees.}
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% Strategy
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A small modular reactor simulation using industry-standard control hardware
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will implement this methodology.
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% Outcome
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Control engineers will implement high-assurance autonomous controls on
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industrial platforms they already use, enabling autonomy without retraining
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costs or developing new equipment.
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\end{enumerate}
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