Research

Set-Based Design

While ship design remains a highly intensive and complex process, advanced design methods such as set-based design (SBD) can provide a structured approach to evaluating the design space while moving towards a globally optimal design. SBD has been used for applications in the automotive and aerospace industries, but has recently been proposed for the ship design process. SBD is design by elimination of infeasible or dominated solutions. The SBD process can be described as a concurrent engineering approach. Current research efforts in the area of SBD include adapting to design changes using SBD, improving preference generation within the SBD environment, and improving SBD implementation and design convergence.

Multi-Disciplinary Design Optimization (MDO)

Focusing on preliminary design of ships and other large-scale engineering systems, Multi-Disciplinary Design Optimization is used to coordinate the tradeoffs between competing design disciplines. A new method of MDO is being developed which attempts to model the intent and preferences of an experienced team of engineers in the design process. A form of Fuzzy Hierarchical Control Engineering emulates the decisions made by engineers in the MDO.

Ship Arrangements

The Intelligent Ship Arrangements (ISA) system, under development for more than eight years, is a Leading Edge Architecture for Prototyping System (LEAPS) compatible software system native to C++ or QT. ISA assists designers in developing rationally-based arrangements that satisfy design specific needs as well as general Navy requirements and standard practices to the maximum extent practicable. ISA was designed for use in the early stage of the US Navy design process, allowing designers to gain critical insight by providing the ability to generate detailed three-dimensional semi-automated general arrangements. Generating arrangements earlier in the ship design process opens up the opportunity to perform more detailed analyses (such as survivability) earlier. This is a paradigm shift in general arrangements theory and practice. Research is on going with a recent focus on space projection systems that take the place of growth based compartment arrangement algorithms.

Network Theory Based Ship Arrangements

In recent years, automated “black box” approaches for creating ship general arrangements in early-state design have been developed. Typically these systems generate multiple layouts, evaluate each layout and eliminate poor designs in an iterative process. Though these approaches are powerful and flexible, tradeoffs are made between direct designer involvement, automation and computation time. Network science can be used look at the layout problem from a new perspective, which views traditional design constraints as fundamental underlying relationships among elements to be arranged. In this view, design relationships are used as an information input to layout-related analyses rather than a post-processor for grading layouts. A new approach for generating ship arrangements is being developed that starts with a non-spatial, network theory-based perspective and results in the traditional assignment of shipboard items to designated structural zones.

Flexibility and Modularity in Ship Design

Modularity has become an increasingly cited element in vessel design, as owners and militaries seek highly adaptable ship systems with increasing robustness toward technology and mission change, at reduced costs. Modularity is perceived to address these issues by designing in the capacity to change a vessel’s capability, reducing reconfiguration and upgrade costs among others. However, the evidence supporting these perceptions is largely anecdotal or proprietary, making it difficult for designers to make analytically supportable decisions regarding modularity when faced with more clearly defined acquisition cost implications. Current research is focused on formulating this problem, with multiple ANCR team members approaching it from different ways.

Stochastic Control and Optimization of FLexible Queuing Systems

Operational flexibility is introduced to ship production to alleviate the effects of delays, which ultimately create issues such as high variability in production workload, ineffective production control, and low facility utilization. New production systems and control methods are modeled, with their effects on shipbuilding processes studied. Markov Decision Processes and discrete event simulation are used as system control policy design tools.