Henric Andersson

Modeling and simulation of Saab Gripen's vehicle systems

This paper gives an overview of the modeling and simulation work for the military aircraft JAS 39 Gripens vehicle systems. The vehicle systems comprise fuel, ECS, hydraulic, and auxiliary power systems and also landing gear. Vehicle systems have several modeling challenges such as both compressible air and less compressible fluids that give stiff differential equations, g-force effects, nonlinear cavitation and saturation. It is also a complex system of integrated systems that requires models with integrated system software. Dynamic models based on physical differential equations have generally been used. The physical systems were previously modeled in Easy5 and the software in MATRIXx. Changes in tools where the physical systems are modeled in Dymola and the control algorithms are modeled in Simulink have opened up for new possibilities for more advanced and more complete system simulations. Simulations have been performed during the whole development cycle of the aircraft from concept evaluation to qualification tests. The paper gives some examples from the simulations where system performance and the internal states of the system are calculated.

Methodology for Development and Validation of Multipurpose Simulation Models

This paper describes a framework for development and validation of multipurpose simulation models. The presented methodology enables reuse of models in different applications with different purpose ...

Conceptual Design Using Generic Object Inheritance

Conceptual design for complex products like aircraft and power plants requires a considerable effort since the product models become very large if they are to cover all important aspects for differ ...

Towards Configuration Support for Collaborative Simulator Development - A Product Line Approach in Model Based Systems Engineering

In development and support of complex products such as power plants, automotive vehicles, or aircrafts, modeling and simulation has become an important activity as a basis for knowledge capture. Simulation is used in several steps of the product lifecycle; for evaluation of early design, for system verification, and for user training. With emerging techniques such as tools for high-level modeling, multi-core computing, and visualization, the number of useful models is growing. This paper focuses on reuse of multipurpose models and configuration support in a product line context. A configurator prototype system is presented. The simulator set created from validated models is considered to be a secondary product line. The product set which the simulation models represent is considered to be the primary product line. The Saab Gripen fighter aircraft, together with simulators in which the aircraft behavior, performance, and handling qualities are represented, is used to exemplify application. Integration principles of the systems for simulator configuration, Software Configuration Management, and Product Data Management (PDM) are studied. Preliminary results show that a configurator tool can be used, but there is need to map structures between the simulation and PDM domains.