Object-Oriented Aircraft Modeling with the DLR FlightDynamics Library

The DLR FlightDynamics library, which has been used internally at the DLR Institute of System Dynamics and Control for more than ten years, has recently been released as a commercial library. This paper is a summary of the successful application of this library for aircraft simulation, optimization and control design with an emphasis on UAV applications. The FlightDynamics library is implemented for the object-oriented, multi-physics simulation standard Modelica. By exploiting the library’s full compatibility with the open-source Modelica Standard Library, integrated simulation models of flight dynamics, systems, and a detailed environment model can be achieved. The capabilities of the modelling language allows parametric configuration of different levels of complexity such as three- or six-degrees-of-freedom equations of motion, different coordinate systems, as well as drag-and-drop replaceability of components on all system levels. The models can be simulated in a Modelica tool without intricate trimming procedures. During the past ten years, the library has been in use for numerous aircraft projects including multi-disciplinary aircraft design efforts such as VAMP, or in the preliminary design stage as in the SAGITTA UAV project. Recently, the interest in UAV applications of the library has grown considerably. Integrated simulation models of a high-altitude solar-powered platform have been used for design optimization, flight control law design, mission analysis, and autonomy development. The very same models have also been used in real-time and hardware-in-the-loop simulations for training of the safety pilots, instruction of the operating crew, and development of suitable human-machine-interfaces for special situations such as take-off and landing. The modularity and flexibility of the library has proven highly valuable for these applications