Research On Attitude Control Method For Missiles With Blended Control Of Aero-fins And Reaction-jets

The endoatmospheric interceptor missiles employ blended control of aero-finsand reaction-jets to improve the guidance and control performance againsthigh-speed and highly maneuverable targets. To coordinate the aero-fins with thereaction-jets, there needs an allocation control strategy, and with the constraints andcharacteristics of the nonlinear missile dynamic model, a design process of theblended control becomes much complex than that of traditional aero-fins control.The thesis researched on the attitude control problem for a missile with aero-finsand reaction-jets using the model predictive control.First, the analysis of the attitude control system characteristics was presented,for the missile with the aero-fins control and reaction-jets control respectively. Thisstudy gave the difference in the response rapidity between aero-fins control andreaction-jets control, which indicated the necessity of entering of the reaction-jetscontrol under certain conditions. At the same time, the factors which affected thecontrol performance were summarized, for the missile with the aero-fins control andreaction-jets control respectively. After that, the reasonable conditions and theoccasions for entering the reaction-jets control were given in the last.Second, the thesis designed the attitude control system of missile with blendedcontrol, using the model predictive control method. The attitude control system ofmissile with blended control was modeled with mixed logic dynamic model, whichmade the constraints and characteristics of nonlinear system characterized by asystem of inequalities. Then, the model predictive control method with mixed logicdynamic model was designed, through the parameters regulating of the controller,especially the weighting coefficients. Furthermore, the model predictive controlmethod was solved by being changed into a mixed-integer quadratic programming problem, with which the optimal attitude control instructions in two types weresolved.Last, some simulation was made to prove the rationality of designing theattitude control system of missile with blended control by the model predictivecontrol method, and to show the reasonable principle of the weighting coefficientsregulation in model predictive control.