Response performance and stability analysis of fixed-wing airplane by improved control technique

Abstract

This paper researches response performance increment of a nonlinear fixed-wing airplane(FWA) system by refining stability, fastness and accuracy of state trajectory. Firstly, the airplane models are established in horizontal and longitudinal directions, with the corresponding linearization model proposed to accommodate control design. To increase stability and reduce input cost, Riccati equation based optimal control algorithm is proposed, which seeks the optimal parameters recursively by minimizing the objective function, and Lyapunov function is employed in the stability discussion to show the optimality. Then based on linear matrix inequalities(LMI) technique and eigenvalues assignment, the minimum eigenvalue problem to regulate damping ratio and natural frequency of the system is established, which improves the fastness in system evolving. Furthermore, augmented control system is applied and proven to increment steady accuracy, associated with potential overshoot and divergence in high-order perturbations. Finally, the designed control laws are tested in nonlinear model system by simulation.