M Writing/ERLM/dane_proposal_format.cls A Writing/ERLM/goals-and-outcomes/v5.tex A Writing/ERLM/goals-and-outcomes/v6.tex M Writing/ERLM/main.aux M Writing/ERLM/main.fdb_latexmk M Writing/ERLM/main.fls M Writing/ERLM/main.log M Writing/ERLM/main.pdf
131 lines
6.8 KiB
TeX
131 lines
6.8 KiB
TeX
\section{Goals and Outcomes}
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The goal of this research is to create a methodology for building high assurance
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hybrid autonomous control systems.
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%FIRST PARAGRAPH - INTRO HOOK
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Commercial control systems for nuclear power have been stuck in the past, far
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behind the state of the art of controls.
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% 3-5 SENTENCES KNOWN INFO
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Nuclear power control systems are extremely high assurance system, where
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failures are intolerable. A control failure in nuclear power has a broader
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impact than financial losses. Instead, a failure can create extensive economic
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losses for the power utility, interruptions for local customers, or in the worst
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case, radiological release in the local environment. Because of this, control of
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nuclear power is performed by operators who are extensively trained, use
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detailed operating procedures, and follow strict requirements.
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% GAP
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This method of control has been reliable, but is woefully behind the
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capabilities of modern less critical control systems, and by relying on human
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operators, prevents the introduction of autonomy.
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% CRITICAL NEED
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To bring nuclear power control into the 21st century, we need a way to develop
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autonomous control systems that have strict guarantees and assurance of their
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correct behavior across their operating range.
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% SECOND PARAGRAPH - APPROACH SOLUTION
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To do this, we will blend tools from computer science and formal methods with
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those from engineering and control theory to build high assurance hybrid systems
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to perform autonomous control.
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% RATIONALE
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Hybrids systems have switching behavior, where discrete transitions between
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continuous dynamics occur. Verification of these systems is difficult because of
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these transitions. We will address this difficulty by building autonomous hybrid
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control systems that are correct by construction. We will synthesize the
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discrete mode switching behavior from written operating procedures, while
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utilizing reachability analysis and assume-guarantee contracts to prove that
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continuous modes behave correctly.
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% HYPOTHESIS PAY-OFF/IMPACT
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If we are successful in creating a hybrid control system that is correct by
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construction, we can implement autonomous control systems in nuclear power with
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a great assurance of their safety and performance. Autonomous control is a
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technology that is desperately needed for the future of nuclear power. Nuclear
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plant designs such as small modular reactors or microcreactors have been
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suggested as a way to reduce the enormous capital costs of nuclear power
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construction, but are limited in their feasibility by the increased cost of
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operator staffing per megawatt generated. If we can reduce the quantity of
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operaters needed in these reactors, we can reduce the cost of generating clean
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nuclear power and address increasing energy demands.
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% QUALIFICATIONS
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This work is also situated in the University of Pittsburgh Cyber Energy Center.
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This research is colocated with collaboration across the energy industry and
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benefits from having access to industry-ready control hardware from Emerson.
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The accessibility to industry this research has will ensure that solutions and
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capabilities generated are aligned with industry needs.
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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 PARAGRAPH 1 TITLE
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\item \textbf{ Synthesize written operating procedures into discrete automata.
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}
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% STRATEGY
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Discrete automata are the backbone of a continuous hybrid system. These
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automata control the swtiching behavior between continuous modes, and are
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directly analogous to operators changing between control laws. The automated
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creation of these automata is a mature field called reactive synthesis.
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Reactive synthesis is enabled by specifying logical requriements of a
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discrete system. These requirements will be created from current written
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operating procedures directly, through an intermediate tool called FRET,
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which uses a natural-language-like format called FRETish to embed
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requirements.
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% OUTCOME
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By using written operating procedures to create the discrete automata, we
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will provide a means for control systems engineers to create discrete
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switching behavior without having to become logical experts. This reduces
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the barrier to entry for using formal methods tools, making high assurance
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switching mechanisms easier to attain.
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% OUTCOME PARAGRAPH 2
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% TITLE
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\item \textbf{
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Build hybrid systems using correct by construction principles.
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}
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% STRATEGY
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In addition to the discrete system, hybrid systems use continuous modes
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between discrete transitions. These continuous modes will be constructed
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using standard control theory practices, but will use formal methods to
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ensure their correctness. Because the discrete modes and their transitions
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will already be specified from operating requirements, the continuous modes
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will be examined to ensure that only allowable state transitions can be
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reached.
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% OUTCOME
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This way, controls engineers can build continuous modes exactly as they
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would before, but iterate on their designs to ensure broader system
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correctness.
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% OUTCOME PARAGRAPH 3 TITLE
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\item \textbf{ Create autonomous control systems with strict safety
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guarantees. }
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% STRATEGY
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By combining the discrete and continuous components while building proof of
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their correctness along the way, we can translate these capabilities into
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realizable autonomous systems for nuclear power. We will use the methodology
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presented in this proposal to build a candidate control system using a
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simulation of a small modular reactor in combination with an Emerson Ovation
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control system.
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% OUTCOME
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By realizing an autonomous hybrid control system using this methodology, we
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will generate evidence that autonomous hybrid control can be realized in the
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nuclear industry with current controls equipment.
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\end{enumerate}
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% THIRD PARAGRAPH - IMPACT
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% INNOVATION
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The innovation in this work is the implementation of different formal methods
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technologies for the purpose of building hybrid control systems. These
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technologies will allow us to build hybrid systems with behavior we can ensure.
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% OUTCOME IMPACT
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The way that these technologies will be implemented is also designed to incur
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the smallest amount of cost possible for possible recreation in industry.
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Controls engineers should be able to find this work approachable, and
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implementable in new nuclear technology control systems.
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% GENERAL IMPACT
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New control systems, especially autonomous control, are critical to advancing
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the prevalence of nuclear power. Small modular reactors stand to answer the next
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energy generation challenge in the United States, but must address the
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significant operating cost required by current staffing limits. This work will
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allow new reactors to reduce the amount of operators required and improve the
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economic feasibility of new reactor designs.
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