On robust fault-tolerant control of missile control system

In order to avoid ballistic missile self-destruction because of sensor failures caused by element aging of long time storage, a reconstructed feedback robust fault-tolerant control scheme is presented. A fault detection method based on the adjacent coefficient of Mallat wavelet is proposed first so that the fault information, which is masked by several elastic oscillation signals with time-varying magnitudes and frequencies, can be extracted efficiently. As soon as a fault is detected, the switch control unit immediately isolates the failed sensor and switch from the original control model to the reconstructed one. To maintain the stability of the system and control the tracking error in case of time-varying of missile parameters, a frequency domain robust stability control is designed, so that speed test feedback of engine swing angle and gain feedback of normal sensor are used to ensure the control stability and restrict the tracking error within a designed value. Finally, the effectiveness of the method is shown by an example of a Soviet missile flight simulation. © 2007