Implementations of real-time system identification using recursive techniques

Recursive identification techniques offer the ability to compute the transfer function of a system in realtime. This mathematical representation of a system may be used for various tasks such as health monitoring and feedback control. This paper presents the mathematical development of the Fast Transversal filter. It follows the work of Juang (1994), but adds to it by the introduction of a forgetting factor to accommodate changes in the plant. The FTF´s ability to track plant changes in real time offers applications in adaptive feedback control and adaptive fault detection. An example of the use of the FTF in feedback control is presented for a simple plant. Also, it is demonstrated that the FTF may be used to estimate a mathematical model of a Flight Control Computer for command signals during the Autoland phase. The example shown in this paper is for a B737 Autolander.