Development of a product modeller for concept ship design
The time-to-market for new ships is often too short to allow for developing and evaluating alternative solutions. Contracts are often concluded on the basis of concept ship designs that took 4 - 8 weeks to develop, allowing only simplified and limited analysis and simulation to be carried out. Time constraints during the pre-contract phase also adversely affect innovation, i.e. the introduction of new technologies and solutions. Uncertainty regarding the reliability of new technical solutions, build strategy, estimated costs etc are compensated by “safety” margins, hereby diminishing the competitive capability of the design.
ICT achievements over the past years in supporting the ship design process have been significant:
• Allowing to create more data on proposed designs
• Providing different views on activities in an early stage of the development
• Providing more accurate results
• Supporting more advanced analysis tools.
To investigate and develop creative and innovative solutions during concept phase of the design, the designer requires a tool that does not enforce detailed definition and allows easy reconfiguration of arrangements and systems. Current CAD systems are by far the most common software tools used to support design. However, these systems mainly use a standard set of parameterized primitives (points, lines, surfaces, solid volumes, holes, etc.) that can be adjusted and combined to represent a design.
The advantage of these CAD systems is the very generic nature of the primitives: they are almost unlimited in defining geometric solutions. First principle tools, however, often require detailed definitions. Moreover, the required level of accuracy before contract (i.e., de-risking) often results in increased levels of detail. However, the time required by a designer to shape a ship concept through assembly of these primitives is far too long.
Therefore, a different, more advanced method is needed to define ship designs to the required level of detail during concept phase. The development of a new approach is proposed based on the use of pre-defined ‘high level primitives’. It must be possible to use these primitives like parametric building blocks, similar to rubberized LEGO, to be morphed, combined and assembled individually with a typical build-up approach in order to generate the topologies of a potentially infinite amount of different ship designs.
By organizing these parametric building blocks into different pre-defined classes, related design information can be stored, thereby encapsulating both the knowledge recognized by all agencies to perform certain tasks and the rules and constraints that determine the behaviour of a class. Re-use of topologies shall be maximized to further speed up the design process. It should also be possible to add the detailed topology of previous designs to the model. In this way also the level of detail can be further increased.
The building block approach should be developed as an “overlay” for existing CAD-systems as it is not the intension the develop a completely new CAD-system.