This paper presents a systematic model/controller order reduction method applied to flexible aircraft. The method, based on mixed μ -synthesis, determines which flexible modes can be truncated from the full-order model of the aircraft and finds a corresponding reduced-order controller preserving robust closed-loop performance. This method is of interest for practical model and controller reduct...

In this paper, a simplified aircraft system model is developed correctly emulating the nonlinear dynamics of complex aircraft models under closed-loop control. The simplified model is based on Dubins models used in optimization algorithms for trajectory control of multiple Unmanned Aeriel Vehicles (UAVs). Algorithms optimizing area coverage for reconnaissance based on UAV capabilities, fuel rem...

In this paper, global optimisation and nonlinear simulation are used to search for the worst-case control demands which may be input by a pilot flying a modern high performance aircraft with a full authority flight control law. The flexibility of global optimisation is exploited to simultaneously search for worst-case pilot inputs and worst-case combinations of uncertain parameters in the nonli...

A dynamic model for the longitudinal axis of a conventional takeoff and landing (CTOL) aircraft is presented. Non-minimum phase characteristics in this model result from the fact that the process of generating an upward pitch moment produces a small downward force, causing the aircraft to lose altitude. The model is not full state linearizable and the internal dynamics which remain after input-...

In this paper, parametric and numerical model of the DC motor, connected to aircraft propellers are extracted. This model is required for controlling trust and velocity of the propellers, and consequently, an aircraft. As a result, both of torque and speed of the propeller can be controlled simultaneously which increases the kinematic and kinetic performance of the aircraft. Parametric model of...

Tests, using small scale models of the Curtiss-Wright X-100 and X-19 aircraft, have been carried out to investigate the disturbance and spray caused by VTOL aircraft hovering above water. Full scale disc loadings in the range 20 to 70 lb./sq.ft. were represented. Correlation of the model test results with full scale testing of the X-100 airplane over water at a disc loading of 23 lb.sq.ft. and ...

In the process of the optimum design of aprons, solutions should be found for problems and such issues as the optimum area and dimensions of the apron, including the passenger and the cargo the number and dimensions of the gates on the basis of different types of aircraft parking configuration aircraft simulation and arrangement in different time periods of the given day at the airport. In this...

This paper gives an overview of the TAU-Code, DLR’s system for complex flow simulations on unstructured hybrid grids. Starting from a short description of the system and its components, e.g. mesh adaptation or grid deformation, its basic capabilities are discussed. Thereafter recent and on-going developments are presented, such as the adjoint approach or a pilot installation exploiting structur...