Longitudinal dynamic characteristics analysis for controller design of elastic missile

In order to design the controller of cruise missile vibrating in flight, the longitudinal dynamic characteristics of the missile are analyzed in this paper. The intrinsic mode is calculated by using the software NASTRAN. The additional unsteady aerodynamics caused by vibration is investigated, and the longitudinal rigid perturbation motion equations are established according to the linear theory. The dynamic response of elastic vibration can be obtained after the additional unsteady aerodynamics loads are substituted to the equations as input of disturbance. The results can provide initial data for stability analysis, precision analysis, guidance and control system design. The output response shows that the longitudinal attitude variation caused by elastic vibration will be very small when the aerodynamic and structure stability are satisfied, and the elastic vibration will not influence flight stability, the adverse effects of vibration must be eliminated by the way of filtering or the other methods.