Adaptive Dynamic Surface Control For Reusable Launch Vehicles

Since the concept of the space transportation systems was proposed, variouscountries in the world especially the space powers invested a lot of money and energyin the extensive and in-depth research. The systems have been updated to the secondgeneration with greater usability after decades of development, which is cheaper, safer,more reliable, and Reusable Launch Vehicle(RLV) is one of them. As the core inreentry flight process of RLV, the control system which is well designed with goodstability and robustness is of great significance to RLV. The dissertation is fastened onthe motion modeling, control technology, and simulation of the control system. Theconcrete contents consist of the following four sections:Firstly, the reentry flight model was studied by the motion equations. The modelincludes two parts: one is Six-DOF nonlinear model of RLV, the other is Six-DOFnonlinear model with uncertainty of RLV. The two models are similar by and large,the main difference of them is that the latter concerns more practical problems, whichmakes it contains uncertainty that must be overcome in the control designing.Secondly, the control problem was studied in this paper and the design of controlrule was designed on account of DSC (Dynamic Surface Control). Based on theSix-DOF nonlinear model, this paper proposed the dynamic surface control (DSC)algorithm, the control system was designed by integration, and the coupling effect ofeach passageway was fully considered in modeling as well as control designing, thusthe anti-manipulation problem which was caused by unconsidering the coupling effectwas effectively solved. Besides, based on the Six-DOF nonlinear model withuncertainty, this paper posed the adaptive dynamic surface control (ADSC) algorithm,then the impact caused by uncertainty was eliminated with effect, and those algorithmwas proved stable by Lyapunov approach.Thirdly, this paper studied the control allocation and there are two actuators,FLAP rudder and RCS, to control the attitude in RLV’s reentry process. Based on thecontrol algorithm, this paper worked out the total control comment of force, and thecontrol application strategy of RLV with FLAP and RCS was presented.Fourthly, this paper completed the numerical simulation under typical casesconsisted of various kind of interference and deviation, the simulation results showthat both algorithms can track quickly and efficiently with high precision, the controlsystem also has good stability and robustness, and adaptive dynamic surface controlalgorithm can reach higher tracking accuracy in general comparatively.