Research On Re-Entry Attitude Control By Adaptive Inverse Control

In this paper, adaptive inverse attitude control of RLV(reusable launch vehicle)is studied. The mathematical model of the orbiter is built and adaptive inverse attitude controller is designed. The controller that solves the control problem through adaptive filtering uses the inversion of the controlled plant as tandem controller in order to control the dynamic characteristics of the plant in open-loop ways. That is, it can avoid the potential instability caused by feedback. Furthermore, it can control the dynamic characteristics and noise canceling of the plant separately. At last, the simulation results show that the controller in this paper is able to accurately and robustly track the command input of attitude angles. The main work is summarized as follows:(1) Let it be supposed that the earth is a rotating sphere and RLV is rigid body, the kinematics and dynamic models of the vehicle are built.(2) Suppose that the sideslip angle is zero, according to the coefficient of dynamic pressure, the uniform mathematical model of RCS and rudder is built and distributed scheme of moments between the RCS and rudders is designed.(3) Through the simplified kinematics and dynamic models, the system is stabilized by angle and angular velocity feedback. The stable system is used as equivalent controlled plant.(4) According to the equivalent plant, the adaptive model, adaptive inverse model and noise canceling model are designed. At last, the whole adaptive inverse control system is given.(5) Based on the fore works, this thesis gives the vehicle's six degree-of-freedom simulation model and the program of the vehicle's 6DOF simulation model with C computer language. The simulation results show that the controller designed in this paper is able to accurately and robustly track the command input of attitude angles.