Joseph Famme CDR USN ret., Dr. CM Lee, Mr. Ted Raitch, Mr. Tobin McNatt

Intelligent Physics Reference Models to Improve Ship Readiness, Response to Battle Damage and Reduce Total Ownership Costs

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Abstract

Navy ship damage experienced in the 1992 Gulf War and subsequent years disclosed unexpected deficiencies of vital systems in both pre battle and post battle conditions that showed the ships were not ready. Knowing and sustaining fleet readiness were the major requirements identified in 2014 and 2015 byseven flag officers. An Intelligent Ship should self-sense its readiness and damage.Ship design tools create realtime CAD/physics process and instrumentationsystemsand hull structural strength models that stress-test and dynamically validate ship systems before releasing drawings to production. This paper reviews Navy programs that have demonstrated that physics reference models can provide accurate ship models for training, readiness assessment and battle damage restoration. Intelligent physicsreference models aboard ship should ‘operate’ in parallel with the ship’s control and condition assessment systems to provide command and fleet commanders near realtime ship readiness assessment. When damage occursthese models can provide command readiness information with animated virtual reality decision displays necessary to restore ship systems readiness and assesshull integrity. Standardizing thecapture and use of physics reference models canalso reduce Navy Total Operational Costs.

Introduction

Knowing and sustaining fleet readiness were the major requirements identified by seven flag officers at the 2014[i]and repeated at the 2015, Surface Navy Association Symposiums. Sustaining high readiness of the kill chain was the toppriority of Fleet Forces Command, with other deficiencies in readiness, ranging from the need for common parts and improved condition based maintenance, to improved training, from individuals to Battle Groups. The common denominator to the fleet requirements was the requirement to know the current readiness of ships, and thus Battle Group readiness, to sail in harm’s way.

Navy Battle Damage reports of four ships in the Gulf War 1992 included the unexpected loss of vital systems including total loss of external and internal communications immediately following the damage. One ship suffered hull damage from a mine such that had the ship been successful in dewatering the compartment, the ship’s keel may have broken, according to NAVSEA post-repair analysis.All four Gulf War battle damaged ships in 1992, and the USS Cole in 2000, lost power and communications when they were struck. Existing Navy processes to assure readiness assessment of ship systems failed to disclose these vulnerabilities.

Navy ships do not currently have shipboard physics-basedreadiness reference modelsto assess and maintain readiness or hull damage models to assess the scope and severity of hull structural failures from damage such as occurred in the 1992 – 2000 period.This paper describes Technology Readiness Levels (TRL) 8 and 9 developed Navy technology that can lead to providing these decision tools toship commanders. This technology can support knowing ship readiness 24/7, that can be rolled up to type and fleet commanders,to providereadiness levels of ships and Battle Groups.

Current Navy methods of assessing the readiness of ship HM&E equipment concentrate on a selectgroup of vital systems, such as the Integrated Condition Assessment System (ICAS). The readiness assessment of the remaining ship systems depends on the diligence of PMS and periodic inspections. This paper describes the development historyand use of Navy ‘as designed’ CAD/Physics HM&E reference models used to verify and validate ship HM&E systems performance during design. These validated physics reference models can be captured and installed on ships to run in realtime as intelligent reference models for ships in normal operations,and for decision aids for engineering casualties and battle damage conditions including hull damage.

Programs reviewed include development and testing of CAD/Physics models with DARPA and NAVSEA demonstrations. Key programs usingphysics modeling started with physics based designed, Navy Smart Ship Standard Monitoring and Control System in 1993, and the LPD17 physics based CAD design 1999. These design tools then migrated directly to the current DDG1000 and Virginia Class shipbuilding programs.

An additional benefit of the systematic use of physics reference models is the potential for dramatic reductions possible in Navy ship Total Ownership Costs (TOC) if the processes used to create and apply physics reference models described in this paper are adopted in ship design in a standardized manner.

Ship Design Technology

The Navy creates CADHM&E systems models of each ship class in 3D CAD with the Process and Instrumentation Drawings (P&IDs) of the HM&E equipment included in each ship compartment.[ii]The LPD17 program added the requirement for dynamic physics verification and validation (V&V) of vital system P&IDs before release of drawings to production. The purpose of these physics models is realtime V&V.The HM&E systems not only need to FIT into the ship, they also must be stress tested to WORK, through all likely operational and battle damage scenarios over the life of the ship, from the warmest seas of the Persian Gulf, to the coldest reaches of the Arctic. Further, the HM&E systems must support the initial combat systems, with space, weight and HM&E reserves for new capabilities as they emerge, especially in the new era of flexible / modular ship designs.

There are two principal sources of ship physics models:

  1. The as-designed CAD/physics models that were created during V&V of the designed P&IDs for the ship prior to the release of drawings to production.
  2. Physics models that ship program offices create to train the crew and maintain the shipafter the ship is delivered. Virtual reality training is based on 3D CAD and physics modeling.

Example sources of physics models are reviewed in this paper in the period 1991 to 2015.The LPD17was the first ‘ship’design that required integrated CAD-Physics design that would support realtime V&V of all vital HM&E / DC systems prior to the release of the drawings to production. LPD17 led the way for similar V&V physics based modeling tools for the DDG1000 ships and Virginia Class submarines.

An example of the second source of physics models is the LCS program where 3D CAD and the physics properties of the ship systems were derived from HM&E drawings and characteristics re-created after the ships were delivered.

Model Fidelity

The important reason for usingdynamically validated physics models created during ship design is that these are the only models whose performance has been validated to run in real time to support the ship as designed. These models have the validated fidelity to represent the systems’ performance standard attributes such as: time, temperature, pressure, flow rates, amps, volumes, and control features, as designed and validated for each specific ship class.

Developing and Validating Ship Systems Reference Models

The difference in the standards of modeling for the two sources of physics models is the fidelity of the models.

Physics models created during ship design are dynamically stress validated in real time across a full spectrum of fluid, gas, and electrical models of the ship. The fluid systems actually ‘operate’with the electrical systems before Dock Trials. Stress tests include using macro commands to impose battle damage scenarios on the ‘ship systems’ while the model is running to validate that systems and automation control capabilities work as designed.

Any level of damage can be imposed using macro commands into the running ship CAD/Physics model during validation to insure all system are battle ready and automation sequences operate as designed. An example is the LPD17 Chill Waterpiping design model of more than 5000 objects. ‘Live’ real time ‘battle damage’ [broken and crimped pipes, penetrated fluid tanks, loss of control elements …]were conducted using the as designed, systems physics models as the reference models.As a result of these tests the piping sizes of critical sections of the chilled water main were made larger from 5 to 6 inches, a task describedby the Navy[iii]as impossible in a completed ship. The concept of running physics reference models with the required fidelityfor V&V was demonstrated. Similar ‘intelligent’ physics reference models with ‘artificial intelligence’ were created and run in parallel with a ‘notional’ ship system as decision aids, as described in the ARPA PRO/A program section in this paper.

The goal of this paper is to present why and how the Navy can and should develop and capture the design intellectual property for use as shipboard command decision Intelligent Physics Reference Models. Use of these models can result in very large reductions in Navy Total Operating Costs,[iv] as described in a paper published in the Naval Engineers Journal.

Modular and Flex Ship Design Technology

Going forward, Navy ship designs will be required to support the new ship design imperative of modular and flex hull designs: hulls with standard plug and play sensor and weapon systems that can be inserted into designed module bays or compartments that have standard connectors for power, heating, cooling, data communications and control. Current practice for modular design is the creation of the Modularity & Open Systems Approach (MOSA) data base for each ship modular / flex ship. This requirement matchesfleet-wide ship ‘module’ locations with the available sensor / weapon systems modules available for deployment.

This paper recommends that at some point going forward that the HM&E components of the MOSA database also include thedynamic physics reference models. These models can be edited, similar to word processing, to add new modular sensor and weapon capability and systems. As a ship is being designed for future systems, these physics modelscan be extended to demonstrate future envelopes of capability such as laser systems. Laser systems, both steady or pulse power, require specific qualities of power and related cooling that may require that a larger HM&E capability be designed into the hull.

Establishing Ship Readiness Standards

Validated P&ID physics models can also represent Readiness Standards for all ship systems, in all conditions, from normal operations to engineering casualty and battle damage conditions and be updated as ships are modernized. These Readiness Standards would compare how the ship systems are performing today as compared to the day the ship systems designs were designed and validated as the drawings were released to production. It would be another way that NAVSEA, fleet and type commanders and commanding officers could monitor the ‘aging’ ofship systems as they degrade over time: i.e. how ‘old’ is the ship?[v]

Availability of Physics Models.

In as much as the ship systems readiness performance standards P&IDs were validated with engineering calculations and analysis and/or real time physics reference models as the ships were designed, what happens to these reference models after the ship wasbuilt? Where are the models now?The answer given by Navy and shipyard engineers is that these reference models all exist, but are found nowin the engineer’s notebooks or archives in the shipyards or at NAVSEA.The physics models of LPD17 vital systems and DDG1000 and Virginia Class P&IDs may be available onengineering CAD design computers that were used for physics V&V prior to release of drawings to production.

Hull Battle Damage

This paper also describes and recommends that to support ships suffering hull penetrating battle casualties, that all ships be equipped with a physics based finite element analysis (FEA) model that was completed for the ship class. In battle damage scenarios these models can be available and operated in parallel with standard Navy engineering and damage control systems to leverage the immersive power of virtual reality information display for real time command decision making.

Advancing Toward Intelligent Ships

Twenty programs are summarized where the Navy useda combination of CAD and HM&Eintegrated physics models to design, validate performance and fit using CAD/physics modeling during the design of the ship. These programs suggest that the design intellectual property created during the ship class design should be methodically captured and used as ships systems performance and decision reference models in the fleet, providing readiness from ship to fleet level as often as is warranted.

The followingprograms describetheuse of CAD/physics based modeling capable of being Intelligent Physics Based Reference Models, 1991-2015:

  1. NAVSEA Standard Monitoring and Control System with Battle DamageControl Program 1991 – 1996.
  2. Battle Damage Control System1992
  3. On-Board Trainer (OBT)1992
  4. ARPA Platform Readiness Operator Associate Program 1994 – 1997.
  5. American Society of Naval Engineers Intelligent Ship Symposium Paper 1994
  6. CNO SmartShip USS Yorktown (CG68) 1996
  7. LPD173DCAD/PhysicsHM&E design 1999-2004
  8. NSRP CAD-Physics Integration 2000-2002
  9. PMS430 FiveNation Battle Force Tactical Training (BFTT) Demonstration 2001
  10. PMS430 Revolution in Training2002
  11. I/ITSEC Total Ship-Crew Model Paper 2004
  12. LCS Program 2004
  13. ONR S3D (Smart Ship Systems) Design Program DDG1000 IPS Power / HM&E Design 2005
  14. CG47 Class Air Warfare Commander Ship Modernization Ingalls Physics Model 2005
  15. DDG1000 and Virginia Class 3D CAD - Physics HM&E DesignTools2006
  16. Physics Model Equivalent to Hot Plant 2007
  17. NSWC Carderock, SBIR N07-132, Hand Deployed Situational Awareness Damage Control Sensor (with Summary Navy Battle Damage 1992 - 2000) 2006
  18. South Korea Physics and Finite Element Analysis: Forensics cause of Cheonan sinking 2010-2011
  19. MAESTRO Hull Structural Strength Finite Element Analysis Shipboard Model 2015
  20. Physics Reference Models Reduce Navy Total Ownership Cost (TOC) 2015

Navy Ship Programs that Utilized3D CAD and Physics Modeling Tools

  1. NAVSEA Standard Monitoring Control System SMCS 1993 - 1996

The importance of the SMCS program was that is was the Navy’s first MCS based on physics based design, distributed microprocessors, distributed dispersal of vital signals, point and click control graphics, and the first control system programmed in object code,ADA.

Distributed microprocessor machinery control systems began withthe Royal Canadian Navy (RCN) in the 1980s with Integrated Platform Management Systems (IPMS). Operating in hostile conditions of the Arctic, RCN ships require failsafe ship control. The RCN designed their IPMS using distributed 286 microprocessors and vital signals, installed in watertight electronics cabinets on triple redundant data busses.

Following extensive investigation of the IPMS technology by the Naval Sea Systems Command (NAVSEA), a contract was issued to the Canadian Commercial Corporation (CCC) for a joint U.S.-Canada R&D program for the Standard Monitoring and Control Systemin 1993.

The Navy SMCSphysics based design used distributed 32-bit processors on a triple busfor maximum reliability under all circumstances, with ten watertight Remote Terminal Units (RTUs) that also retained copies of the vital signals. Each RTU had control panel display that allowed full control, with password protection, and its own battery uninterrupted power supply in case of ship’s power loss.

The value of the design features of SMCS that replicated vital signals in ten RTUs was highlightedwith the USS Cole bombing in 2000. The USS Cole MCS conformed to the then standard practice of maintaining vital signals in the Central Control Room. The small boat bomb detonation occurred outboard of Central Control and all vital signals were lost. The DDG1000 machinery control system is built on a greatly extended,distributed version of the SMCS architecture.

The SMCS systems completed hot plant testing in 1996 on the DDG51 Hot Plant in 1996. When certified, the SMCS was diverted from the DDG51 class to the Navy Smart Ship program (see Smart Ship section).

  1. Battle Damage Control Systems

The importance of BDCS isit being the pioneer system moving damage control plotting from grease pencil and sound powered phones, to PC computer isometric displays of ship compartmentation with overlays of keys systems such as the firemain. BDCS operating with physics based SMCS, or physics based designed ships like LPD17, DDG1000 and Virginia Class, have the ability to use physics based decision aids for their HM&E and DC systems.

Battle Damage Control System (BDCS) was developed to operate stand alone or to be integrated with SMCS, to provided full isometric ship deck plates with DC plotting and overlays, check lists and pull up menus of all Navy Operational Sequence Systems (OSS) Doctrines,and optionally, full physics calculated stability Cross Curves of Stability. Physics modeling of fluids and gasses is possible. A typical BDCS screen is shown.

BDCSPC prototype capability was validated in Sea Trials in 1992 aboard USS Anzio (CG68). Eight coax connected BDCS prototype COTS PCs were installed in the DC stations of USS Anzio (CG68) with the permission of the CO and type-commander to test the concept of electronic plotting / DC decision aids, and the use of COTS computers in a ship environment. After initial crew cultural shock of having a common, self-correcting, DC Plot at all stations, the concept took hold. During the trial period USS Anzio was subjected to a CG Class “EMP’ test. Notable, was that all COTS BDCS PCs were left running, though most navy equipment was secured. The COTS PCs, being in the hull, were unaffected.

  1. Engineering Plant Onboard Trainer Provided by Physics Model for SMCS - 1992

The importance of physics designed SMCS was that it also offered a full,

Realtime operator onboard training (OBT) capability.