Robust Flight Control Design for the HIRM based on Linear Quadratic Control

In this paper the application of Linear Quadratic Optimal Control based tec hniques to the HIRM (High Incidence Research Model) Robust Flight Control d esign problem is considered. The structure of the proposed controller is ba sically a Proportional Integral action, both for the longitudinal and for t he lateral-directional parts, designed with optimality criteria in order to achieve the performance and robustness requirements. Moreover, the control scheme is completed by the compensation of some physical non linearities, some demand shaping filters and a switching logic based on the angle of att ack and on the Mach number. Most of the design requirements are easily sati sfied; some others need a heavier tuning of the controller design parameter s. A procedure to tune such parameters, formulated in terms of an optimizat ion problem, is proposed. Simulation results, from the HIRM automated evalu ation procedure are also provided at the end of the paper, from which it is shown that the proposed controller meets the requirements. (C) 2000 Editio ns scientifiques et medicales Elsevier SAS.