Validation of a small signal probing concept for prognosis on a nonlinear model for longitudinal motion of a Boeing-747

In this paper, real time monitoring of the control system of a Boeing 747 aircraft (B747) is considered by using a pulse-compression probing method. The method extracts small signal characteristics of the targeted system, and detects deviations from the system´s normal behavior with high sensitivity. This paper demonstrates, through a simulated model of a B747 longitudinal motion, the successful application of the probing method in monitoring a nonlinear dynamic system. The paper focuses on the process of determining suitable probing signals and probing structure for the B747, and discusses the monitoring results for two major types of faults in its actuators.