A study of a propulsion control system for a VATOL aircraft (a direct design synthesis application)

The authors present an application of the direct design synthesis (DDS) methodology to the study of the design of a propulsion control system for a vertical attitude takeoff and landing aircraft (VATOL) computer simulation. This application is particularly relevant to modern integrated control systems design methodologies due to the requirements of modern propulsion systems to provide stability augmentation. This requirement necessitates tight coupling between the flight and propulsion control system. A modified version of the Vought SF-121 VATOL aircraft simulation and an F100 engine core was selected. The integrated system was constrained to operate at low-altitude conditions for this analysis. The results of the simulations show that the DDS methodology has merit for consideration in integrated control design applications. The multivariable nature of the methodology allowed the control of engine variables necessary for proper engine operation as well as the control of engine variables that coupled with other subsystems in the integrated system. The requirements for the transient performance on engine thrust generated by the flight control system and the requirements on selected internal engine variables were directly translated into performance parameters. Details of the design and integration were provided along with simulations that showed total system performance during a switch of flight control system modes