1. Optimization

Optimization is a variation of the variables in another workflow in a systematic way, in order to minimize a function subject to a set of constraints. A workflow has to be chosen in the editor. Input and output can be added in the editor based on the available input/output in the chosen workflow.

In the tab Optimization setup, the user specifies the cost function and the constraints to be used. The optimization variables can be chosen from the free variables in the chosen workflow. The initial value, as well as the upper and lower limits for the optimization variables, and the delta for calculation of gradients are suggested based on the chosen workflow, but may be edited by the user.

The user may choose various parameters related to the underlying optimization routine in the tab Calculation parameters, such as desired final accuracy (convergence criterion) and the maximum number of iterations. Automatic normalization is turned on by default. For more details regarding convergence and normalization, see here.

The results can be visualized in the Plot tab while the optimization is running.

1.1. Getting Started with Optimization

The optimization module is a general purpose optimization tool. The user may formulate a optimization problems for any parameterized model using variables. Typical applications are:

  • Mooring system optimization using SIMO, RIFLEX or Coupled.

  • Riser optimization using RIFLEX or Coupled.

  • Optimization of marine operations using SIMO.

Any optimization problem must consist of the following building blocks:

  • A workflow to be optimized with optimization variables as input and cost function and constraint values as output.

  • A workflow with an optimization node referring to the workflow above, and where the user specifies the optimization calculation parameters.

  • A post processor with a cost function to be minimized and constraints to be satisfied.

For guide to setting up an optimization problem, please check the examples available under Help > Examples > Optimization.