Active aeroelastic control with time delay for targeted flutter modes

The dynamic behavior of aeroelastic systems is characterized by multiple numbers of modes. Aeroelastic instability, such as flutter, associated with a certain mode can be stabilized by active control through pole placement. However, the controller can influence or may destabilize other aeroelastic modes due to spillover. In this paper, flutter suppression and flutter boundary extension by partial pole placement in an aeroelastic system is presented by active state feedback having a single time delay in the control loop. This allows the control of the desired mode of interest without influencing any other modes. A quadratic partial pole assignment problem with constant time delay is generalized here for the case of asymmetric system matrices. It is shown with a numerical example that with this approach poles associated with a targeted flutter mode can be stabilized without affecting the other aeroelastic modes. The effect of time delay on control gains and incorporation of actuator dynamics in the proposed framework are demonstrated. Posterior stability analysis is briefly presented for estimating the critical time delays for the controlled system.