Import and Export of Functional Mockup Units in CasADi

This paper presents the recently added support for import and export of functional mockup units (FMUs) in CasADi, an open-source software framework for numerical optimization. Of particular interest is the efficient calculation of derivatives, especially in the context of sensitivity analysis and dynamic optimization. We show how the import interface allows for both first and second derivatives can be efficiently and accurately calculated and - importantly - validated for correctness. We also outline the FMU export interface, which leverages CasADi mature and efficient support for forward and adjoint derivative calculation and C code generation. Finally, potential future developments of the support are discussed.