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Missions

Florida State University



Moving Beyond Point AnalysisExpand the current “design point” analysis capability by enabling time-integrated mission analyses including aggregating the results into mission level metrics

Missions will allow the Navy to:• Perform trade-off analyses of competing

designs• Allow engineers to answer questions such as

“How much energy storage is needed for a given design?” or “What is the fuel consumption over a mission?”

• Permit conceptual designs to be tested across suites of missions and with different payload packages allowing for an evaluation of the platform’s effectiveness

A mission is executed by integrating a series of static simulations over specified periods of time. The results are then rolled up to provide the mission level metrics.• The first phase defines the software

requirements necessary for the S3D environment to support mission level analyses

• Evaluate the relevant metrics (weight, fuel consumption, and other measures of effectiveness and performance) that will be selected by the domain experts included in this task

• Develop the framework and basic functionality of S3D to evaluate and compare competing design concepts by exercising these missions

• Exploration of methods that will automatically configure the ship systems to intelligently respond to user-issued directives in the form of high level instructions



Define Time Based Mission and Mission Segments

• Time based missions, user specifies duration and speed of each segment• E.g. Analyze yearly fuel consumption for a set of designs given typical usage patterns• Segment definition begins with specifying operational state (cruise, battle, etc.)• Segment duration is specified in days, months, hours, etc. or as a percentage of the total mission duration• Segment speed is specified as a whole number in knots• Based on duration and speed, the tool can calculate the distance traveled during the segment





Define Geospatial Mission• Time/Geospatial based missions, user specifies distance and speed of each segment

• Segment definition begins with specifying operational state (cruise, battle, etc.)• Segment distance is specified via waypoints chosen on a map• Segment speed is specified as a whole number in knots• Based on distance and speed, the tool can calculate the duration of the segment



Error Handling• Engines are capable of raising specific error events that fall into one of

the following categories– Message – event is viewable by the user, but does not affect the simulation– Warning – event is viewable by the user, potentially affects the result of the

simulation, but the simulation is allowed to continue– Fatal – causes the simulation to immediately stop

• Different types of error events fall into one of the above categories by default, but may be changed by the user– For example, Insufficient Fuel Provided error is fatal by default, but the user

may set that type of error as a Warning in order to gain better insight into the evaluation of the ship against a mission (user assumes the ship will be refueled as needed)



Mission Analysis Tool



Setting Electrical Plant Alignment



Simulating Electrical Plant Alignment



Setting Cooling Plant Alignment



Quasi-Steady State Solver• The Quasi-Steady state solver computes steady-state solutions for

changing operating points.• The notion of time has been incorporated into the power flow

solver in order to support the evaluation of a series of mission segments that constitute the mission being analyzed.

• Models can now appropriately account for their change in state – i.e. a fuel tank has a reduction in available fuel, an energy storage device is 10% depleted, etc…– A change in state for one component during the execution of a mission

segment may cause cascading effects to other equipment (for example DC disconnects, breakers, loads, etc…).



Event Scheduling• System composed of two

energy storage devices, supplying a common load

• Energy storage components are configured (via Python interface), to immediately change to charging mode once fully discharged

• Once the simulation starts, the energy storage devices each:– Compute the time at which they will run out of energy, given the

current power draw– Schedule an event with the solver for that time

• Energy Storage 1 has scheduled an earlier event, so the solver will run until that point

– Energy Storage 1 is exhausted and switches to charging mode—schedules an event with the solver for the time it computes it will be fully charged

– Energy Storage 2 re-evaluates the point it will run out of energy, and reschedules its event

• Energy Storage 2’s scheduled event is the earliest event– Energy Storage 1 is sufficiently charged and switches to discharging

mode—resschedules an event with the solver for the time it computers it will run out of energy

– Energy Storage 2 is exhausted and switches to charging mode—schedules an event for charging completed

• Energy Storage 2’s scheduled event is the next earliest event– Energy Storage 2 is fully charged and switches to discharging mode—

schedules an event with the solver for the point it will run out of energy

– Energy Storage 1 re-evaluates the time it will run out of energy and reschedules its event



Executing the Yearly Fuel Consumption Mission



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