Research On Attitude Control And Control Allocation For Reusable Boosted Vehicle

To meet the development of space research, military reconnaissance, and rapid global strike capability with low cost and reusable transportation system, reusable space launch vehicle came into being. During many kinds of reusable vehicle concepts, reusable boosted vehicle (RBV) is a kind of unpowered and gliding back vehicle with the features of wide flight range, large Mach number range, complex manipulation and heterogeneous redundant actuator. Hence, the problem of attitude control and heterogeneous redundant actuator control allocation for RBV becomes one of the most challenging topics for modern flight control engineers.According to the special characters of different flight phases and the redundant configuration of different control actors, this thesis focused on the attitude control and control allocation of RBV. The main achievements are as following:(1) Aiming at the whole airspace and large maneuvers characteristics, the nonlinear six-degree-of-freedom model is built. And the corresponding mathematical model of the different flight phases is provided.(2) Aiming at large angle of attack maneuver, robust adaptive dynamic inversion flight control strategy based on neural network for RBV is proposed. Based on the time-scale separation of RBV model, and under the assumption that the angle rates in fast loop couldn't be obtained instantaneously and its dynamic inversion is performed exactly, the stability of slow and fast closed-loop dynamic inversion system is proved strictly with Lyapunov theory. And under time-scale separation conditions, the band width of fast loop is designed. To deal with uncertainty of system model, a kind of robust adaptive inversion control laws based on neural network is designed. Ultimate uniform boundedness of closed-loop control system for RBV is proved. The simulations validate that this method is effective and can improve the control ability and robust performance dramatically for uncertainty models.(3) Aiming at the flight requirements of different airspace for RBV, multi-space blending control based on linear parameter varying gain scheduling is proposed, and airspace parameters of RBV is composed of angle of attack, Mach number and aititude. According to different airspace parameters, LPV gain scheduling controller is designed for the airspace and fusion function is constructed. Finally the whole airspace LPV controller is formed with the different airspace controllers. The robust performance of the closed-loop system is analyzed using parameter-dependent Lyapunov function. The simulations indicate that this method could reduce running time and is of perfect robust ability.(4) A kind of reconfigurable dynamic control allocation method for RBV heterogeneous redundant actuator is proposed. A kind of improved fixed-point (IFP) method was designed for the control of aero surfaces and reaction control system (RCS) of RBV. The control allocation considering the dynamic characters of aero surfaces was discussed, and its effectiveness was proved in detail. Under the station where aero surfaces are out of work, the control system reconfiguration was carried out using control allocation together with robust adaptive inversion control law. The comparison between different control allocation methods indicates that the control allocation method could fulfill the reconfigurable dynamic control requirement of onboard computers and get better performance even when the number of actors is more than 20 under strict control restrictions.(5) A complete six-degree-of-freedom simulation system for guidance, navigation and control (GNC) of RBV was built up. The high-accuracy flight control simulation of RBV with high-fidelity was carried out using MATLAB/SIMULINK.