On the feedback linearization control for hypersonic flight vehicle analogy X20

In this paper, we consider the control problem of the hypersonic flight vehicle analogy X20. Through a careful analysis of the relationship between the aerodynamic coefficients and their independent variables of height, Mach number, attack angle, sideslip angle and rudder angel, we fit the aerodynamic coefficients according to the independent variables and give their analytic expressions. And we establish the affine nonlinear control model of analogy X20, which is proved the input-output linearization. On the basis, we design the feedback linearization control law. When there being the uncertainties of aero density, aerodynamic moment coefficients and inertia, the simulations are performed for the original dynamics, which include the earth rotation and whose aerodynamic data come from the aerodynamic data table directly. The simulation results indicate that the resulting control law ensures the control targets and has strong robustness.