Study On Control Method And Integrated Flight/Propulsion Control Method Of Compound Adjustable Ducted Rocket

The ducted rocket is considered to be the ideal power plant for the medium supersonic,medium range tactical missile.But the existing ducted rocket uses fixed-geometry structure,the flow channels of inlet and nozzle are designed according to low speed requirements,resulting in serious loss of engine performance during cruising flight.The inlet / gas generator / nozzle compound adjustment is introduced to improve the engine performance.The operating characteristics of the compound adjustable ducted rocket require an effective control on the compound adjustment.Due to the differences on the control variables,dynamic characteristics and control objects,the current control methods are flawed.In this paper,for the compound adjustable ducted rocket,the dynamic modeling method,control method and integrated flight / propulsion control method are investigated in detail:(1)The equilibrium models,dynamic models of main parts of the compound adjustable ducted rocket and the disturbance propagation models are founded,and synthesized into the nonlinear dynamic model of the engine.The dynamic response characteristics of ducted rocket during flight condition disturbance and inlet / gas generator / nozzle adjustment are studied by simulation,and the effects of disturbance propagation dynamic process and its treatment method on ducted rocket are also studied.(2)By selecting the engine thrust with desired control and the afterburner working pressure which reflecting the operating condition of the engine as the control variables,the small disturbance linear dynamic model of the compound adjustable ducted rocket under flight condition disturbance and inlet / gas generator / nozzle adjustment is established.Based on the nonlinear dynamic model,the linear dynamic model is verified by simulation.And then the physical significance of the parameters and the change rule of time constants and gains with flight condition are also studied.(3)Based on the analysis of the control objects and restrictions,the control strategy that improving the optimal performance of the ducted rocket by inlet adjustment,controlling thrust / afterburner working pressure and protecting the work state of the ducted rocket by gas generator / nozzle adjustment is established with the study on the dynamic response characteristic of ducted rocket.The simplification method of the inlet adjustment control and the calculation method of control command are studied.The coupling characteristics between thrust and afterburner working pressure loops are weaken by INA method,and the feedback variables without anti-regulation characteristics are constructed by information fusion in frequency domain,then the PI controllers are designed.Given on this basis,the design procedure of the thrust / afterburner working pressure controllers is put forward,and then the control method is validated by nonlinear simulation.According to the different working limitations of the ducted rocket,various active / passive protection methods are introduced,and the steady and dynamic performances of passive protection method are studied in detail.(4)The coupling characteristics between the flight and the propulsion of the missile are analyzed,and then the flight control system and propulsion control system are synthesized by hierarchical dispersion method to construct the IFPC system.The calculation method and assigning method of the control commands in the IFPC system are studied respectively.According to the function of the integrated system and the physical characteristics of the subsystems,the integrated flight/propulsion simulation platform is built,and then the IFPC method is validated by simulation.