Signal processing for output signals of the inertia sensors in the missile control system

To improve the reliability of missiles, the reconfiguring fault tolerant control system (RFTCS) should be built in the missile control system. The key problem for building RFTCS is to separate the rigid body angle signal and different order elastic oscillation caused angle signals (RSADS) from the output signals of inertia sensors (OSOIS). Firstly, the accurate location characteristics of FFT in frequency domain are used. OSOIS are transformed by FFT. The frequencies at extrema of frequency response obtained via FFT are the frequencies of RSADS. Secondly, an elliptical filter is designed to let the signals of the frequencies go through and the test signal is designed with combined sine signals whose initial phases are zero and whose frequencies are the frequencies at extrema. The test signal is filtered by the elliptical filter. The phase lag of each sine signal in the test signal is the initial phase of each filtered sine signal. OSOIS are also filtered by the elliptical filter. The filtered signal separated from inertia sensors are adjusted with the phase lags test by the test signal. Finally, RSADS are obtained in real-time. The simulation shows the effectiveness of the approach.