Coordinated Control Of Deformation And Flight For Morphing Aircraft

The morphing aircraft can change the geometric shape initiatively or passively in flight according to the different flight conditions and missions,to guarantee the optimal flight performance in various flight stages.So the morphing aircraft can improve the environment adaptability and satisfy large-envelope multi-mission requirements.The advantages and potentialities of the morphing aircraft make this concept vehicle receive a lot of attention from many countries.Many researches have been developed on how to design the rational and feasible deformation structures to accomplish the desired shape changes,however there still exist many problems on how to coordinate the deformation control and the flight control while the aircraft makes deformation in flight.The coordinated control of the deformation and the flight for the morphing aircraft is studied in this paper.The dyanmics of two kinds of morphing aircraft,the span-variable aircraft and the thickness-variable aircraft,are constructed.The characteristics of the morphing and the flight are analyzed.The various morphing flight processes and the coordinated control stratagies under various mission requirements are studied.And a principle demonstration system for the morphing flight of the morphing aircraft is developed.Firstly,the aerodynamic parameters modeling and the nonlinear dynamics of the morphing aircraft are studied.The longitudinal aerodynamic parameters of two kinds of morphing aircraft at various operation points in the flight envelope are obtained by DATCOM,an aerodynamic simulation software.The functions of the aerodynamic parameters about the structural deformation are established,which demonstrate clearly that the structural deformation can change directly the aircraft aerodynamic performance.This is an important characteristic of the morphing aircraft apart from the conventional ones.Furthermore,the longitudinal nonlinear dynamics of the morphing aircraft including the structural deformation are constructed,which show the essential characteristic of the morphing aircraft that there exists some coupling between the aircraft motion and the structural deformation.Secondly,the coordinated control of the steady flight during morphing for the morphing aircraft in cruise during structural deformation is studied.The longitudinal linear parameter-varying(LPV)model of the morphing aircraft in some certain flight condition is constructed.Then a novel robust gain-scheduled control strategy based on the nominal LPV model is proposed,which avoids arbitrary parameter space division or controller interpolation of ordinary gain-scheduled control method,to guarantee the global stability of the closed-loop plant.Consider the compound disturbance,a novel robust gain-scheduled control with sliding mode disturbance observer(RGSC/SMDO)strategy is proposed,to guarantee the robustness of the closed-loop plant throught compensation control from disturbance observation.The simulation results show that,the flight characteristics and the motion modes of the morphing aircraft can be affected directly through structural deformation.The RGSC/SMDO can provide a higher stability and a stronger disturbance rejection for the morphing aircraft in the steady flight during morphing.The morphing aircraft can perform the same flight mission with less fuel consumption through structural deformation,which means a great advantage over conventional aircraft.Next,the coordinated control of the morphing-cooperated flight for the morphing aircraft in maneuver cooperated with structural deformation is studied.The longitudinal T-S fuzzy model of the morphing aircraft in the entire flight envelope is constructed.Then a novel fuzzy robust H? control(FRHC)strategy is proposed,to guarantee the global stability and the robust of the closed-loop plant,and to track the flight target asymptotically.To reduce the conservation of control synthesize,the discretization of the continuous T-S fuzzy model of the morphing aircraft is made.Then a novel discrete fuzzy robust H? control(DFRHC)strategy is proposed,to guarantee better the global stability,the robust and the tracking accuracy of the closed-loop plant.The simulation results show that,the morphing aircraft can perform a cross-altitude cross-velocity morphing-cooperated flight by the DFRHC.The morphing aircraft can improve the maneuverability and expand the flight envelope cooperated with structural deformation,which means a great advantage over conventional aircraft.Afterwards,the coordinated control of the morphing-aided maneuver for the morphing aircraft to track the flight target is studied.Taking the structural deformation as an extra operation,the longitudinal nonlinear dynamics of the morphing aircraft with morphing-aided manenuver is constructed.The input-output linearized decoupling model is obtained via feedback linearization.Then a novel non-singular dynamic terminal sliding model control(NDTSMC)strategy is proposed,whick converges the plant states within a finite time,and eliminates the control chattering better.The global stability,the strong robustness and the tracking accuracy of the closed-loop plant is guaranteed by the NDTSMC.The simulation results show that,the tracking performance of the morphing aircraft is improved utilizing morphing-aided maneuver by the NDTSMC.The maneuverability and the disturbance rejection capacity of the morphing aircraft with morphing-aided manever are demonstrated stronger than the conventional ones.The morphing aircraft can perform a better flight with a higher efficiency through morphing-aided manever,which means a great advantage over conventional aircraft.Finally,a principle demonstration system for the morphing flight of the morphing aircraft is developed.The system includes three parts: a morphing aircraft flight control computer,a wing deformation control computer and a morphing wing smart simulation platform.The distributed-actuated morphing wing smart simulation platform based on the Controller Area Network(CAN)is researched and developed.The wing deformation control software and the morphing aircraft flight control software are developed based on the C++ and MATLAB.The demonstration experiments for the steady flight during morphing,the morphing-cooperated flight and the morphing-aided maneuver of the thickness-variable aircraft are conducted,which demonstrate the principle and the scheme of the coordinated control for the morphing aircraft,and provide a valuable reference idea for the design and realization of future morphing aircraft and aerospace vehicle.