Lab2 Flight command

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Politecnico di Milano – Department of Aerospace Science and Technology Modeling and Simulation of Aerospace Systems – AY 2015/2016 (F. Topputo) Exercise 2 Starting from Exercise 1, add a servo-control to actuate a symmetric flight command such as shown in fig. 1, completing the dynamic model and including the frequency analysis. The contrast force F(x), is characterized by the profile shown in Fig.2, positive in compression. As input of the system y(t), consider the sequence shown in Fig.3, to be applied after the ignition/starting transients. At the beginning, the actuator is in center position Figura 1: Hydraulic system and servo control. PISTON FORCE 40 30 20 10 0 -10 -20 -30 -40 -100 -80 -60 -40 -20 0 20 40 60 80 100 Displacement [mm] Figure 2: Reaction Force as function of the displacement. DEMAND 100 80 60 40 20 0 -20 -40 -60 -80 -100 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Time [s] Figura 3: Input (demand) as a function of time. Load (kN) Displacement [mm] x [mm] F [N] -100 -28921 -80 -27650 -60 -25010 -40 -19921 -20 -11398 0 0 20 11398 40 19921 60 25010 80 27650 100 28921 t [s] y [mm] 0 0 0.25 80 0.50 80 0.75 100 1 100 1.25 -60 1.50 -60 1.75 0 2 0 Politecnico di Milano – Department of Aerospace Science and Technology Modeling and Simulation of Aerospace Systems – AY 2015/2016 (F. Topputo) Parte A Taking into account the system in Fig.1, the reaction force in Fig 2 and the data at the bottom of the page: 1. Size the actuator; 2. Compute the loss coefficient (due to leakage), cL in the actuator; 3. Write the characteristic equations of the system. Parte B Using the lab 1 data (in case of conflict, use the data at the bottom of the page):, 1. develop a numerical code to simulate the system, in order to compute at each time instant: 1) flow rates and pressures in the…