Optimization of feedback/feedforward control gains for aircraft mode decoupling

Abstract

Tracking control law is the control scheme to make the system output follow a nonzero reference command signal. By combining the tracking control law with an eigenstructure assignment, and applying it to an advanced aircraft such as control configured vehicles, mode decoupling can be achieved. The tracking control law usually consists of feedback control of output states and feedforward control of reference input. In this paper, a new design methodology is proposed by utilizing the nonlinear optimization technique t o design an effective controller. The proposed algorithm utilizes the eigenstructure assignment and the optimization technique to compute the feedback gain matrix (for aircraft mode decoupling) and feedforward gain matrix, respectively. I t is shown that the existing algebraic formula for computing the feedforward gain matrix is the limiting cases of the proposed methodology. A concurrent optimization technique to obtain feedback and feedforward gain matrices is also proposed, which results in a more effective controller. The design methodology is illustrated by application to an AFT1 F-16 a.ircraft .