Dynamic Modeling And Control Of Air-Breathing Hypersonic Vehicle Considering Aeroelastic Effects

Scramjet powered air-breathing hypersonic vehicles(AHSV)have short voyage time and low launch cost in the aspect of space launch,and also have the prompt global strike capability in military applications.As a result,the related research regarding the hypersonic technology is paid more and more attention in the world.Compared with traditional vehicles,hypersonic vehicles are characterized as significant aero-themo-elastic-propulsion interactions and considerable uncertainty,as a result to bring the new challenges in the control system design.Elastic fuselage design not only strengthens interactions between structure and propulsion systems,but also enhances difficulty in the controller design because elastic frequencies are close to the bandwidth of actuator.Therefore,this paper will focus on the interrelationship between the elasticity and control for hypersonic vehicles.First,parametric modeling method is used to build the rigid longitudinal model of AHSV.Then,based on this,the elastic structure model is established using the finite element method.Afterwards,Lagrange equation and principle of virtual work are applied to build the longitudinal model of the elastic aircraft.Specifically,the relation of rigid and elastic mode is established through forces and moments.Finally,the control-orient elastic AHSV model is obtained based on the Morris sensitivity analysis method.In order to study the elasticity characteristics of AHSV,detailed analyses are made on this elastic surrogate model.This includes comparative analysis of static properties,dynamic properties and open loop system performance indicators of rigid and elastic models,and further analysis of structural stiffness on static properties,dynamic properties and open loop system performance indicators regarding structural stiffness change.Furthermore,H_∞controller is designed to investigate the impact on the control system design with repect to structural elasticity.In addition,the control design methods using elastic modes feedback and adaptive notch filter are proposed for the tracking problems of velocity and altitude of AHSV,and simulation results are provided to verify the effectiveness of the presented methods.