DIGITAL ADAPTIVE FLIGHT CONTROL SYSTEM FOR AEROSPACE VEHICLES

Abstract

The application of digital adaptive control techniques to flight control of an aerospace vehicle is presented. A digital adaptive flight control system is described which uses identification and synthesis processes to determine what changes in control parameters are required to adapt to changes in the dynamics of an aerospace vehicle as it experiences a wide range of flight conditions. Identification of vehicle dynamics is accomplished hy an improved identification technique that uses correlation of control signals caused by input fluctuations and does not require special test inputs that may disturb normal system operation. Synthesis of digital compensation to provide stabilization and desired response characteristics is accomplished by means of an analytical synthesis technique that determines the parameters of a digital compensator from information about the vehicle dynamics obtained by the identification technique and from performance criteria established by the system designer. A digital computer simulation of a digital adaptive pitch rate flight control system was performed which included identification of a fourth-order aerospace vehicle and actuation system and synthesis of a fourth-order digital compensator,