DOML -- a Compiler Environment for Dynamic Optimization Supporting Multiple Solvers

Abstract

The Modelica language may serve well as a base for defining optimal control problems, given a few relatively minor syntax extensions. One example proving that point is Optimica and another one is DOML (Dynamic Optimization Modeling Language) -installed on IDOS (Interactive Dynamic Optimization Language) and described in this paper. The DOML implementation is, actually, heavily based on the (open source) compiler of Optimica but it provides a number of important features absent in its precursor. One main extension of the compiler lies in its built-in mechanism supporting the use of many different optimization solvers (selected on the fly, depending on the content of the problem definition) and to seamlessly add new, external, solvers. In result, the range of problems that may be specified with DOML and solved in the IDOS environment is quite wide and keeps growing. The scope of problems ranges from some static optimization problems through regular ODE, parametric optimization, minimum time problems, up to DAE with higher index. DOML language extensions also provide preliminary support for multi-objective optimization and PDE problems.

Equation-based modelling for dynamic optimization of district scale energy systems – a scalability study

“…In order to enable Modelicabased optimization, the language extension Optimica [15] was introduced, which among other functionalities, allows the formulation of objective functions and constraints. Based on Optimica, the language extension Dynamic Optimization Modelling Language was introduced [17]. Modelica-based dynamic optimization is currently supported by several open source tools including JModelica, OpenModelica or IDOS and commercial tools including OCT or TACO.…”

IDOS - (also) a Web Based Tool for Calibrating Modelica Models

“…The DOML format provides a mean for describing an optimal control problem in slightly extended Modelica syntax. It is very similar to Optimica ( [1], [2]) and in fact its implementation is based on the JModelica.org Optimica compiler, although a number of features proposed in DOML set it apart from Optimica (these are described in detail in the accompanying paper [24]).…”

“…Since all these solvers were to be invoked from the DOML script this approach enabled us to provide quite precise requirements for the dynamic optimization language. In the paper [24] we describe how that approach has been materialized in the form of new constructs put into the Modelica framework.…”