Abstract: In this paper, stability problem of elastic vehicles is studied with the effect of unsteady aerodynamic forces considered. Longitudinal equations of disturbance motions with the actions of unsteady aerodynamic forces are derived. A method of analysis of the effect of aeroelasticity on the stability of elastic vehicles by using a simplified mathematical model of unsteady aerodynamic forces is proposed. Also synthesis of the optimal design of active control system is studied from the view-point of coordinating the design of the active feedback control with the choice of positions of control surfaces and sensors(gyros) locations from the stand point for the efficient suppression of elastic vibrations of the vehicle.

Key words: unsteady aerodynamic forces, elastic vehicles, dynamic stability and active control