DEVELOPMENT OF AN ADVANCED DIGITAL ADAPTIVE FLIGHT CONTROL SYSTEM.

Abstract : A new approach for a digital adaptive flight control system was developed. This approach consists of an explicit identification of the vehicle transfer function coefficients coupled with a control system parameter optimization to minimize an integral square error type criterion of performance. The investigation included theoretical studies which further developed the identification and parameter adjustment equations and established their effectiveness and the limits within which they are effective. These theoretical studies also established methods for the numerical integration which is needed in the identification and a search technique which is needed in the parameter adjustment process. Working equations which were used in the programming for the digital studies are included. The extensive all-digital and the hybrid simulation set up for this study is described. The all-digital simulation was useful in testing the sensitivity of the identification and parameter adjustment by taking numerous short runs under varying conditions. The hybrid simulation permitted testing the proposed methods in conjunction with realistic airframes in actual closed autopilot loops on realistic trajectories.