Active Segment Of The Manned Launch Vehicle Fault Detection Technique

The fault detection techniques for manned space flight guarantee the security of cosmonaut. Because of extensively propulsive action, the boosting stage of launch vehicle becomes the most danger moment for cosmonaut. After faults occur, there often have little time left. So it must make decision and take contingency measure. A quick and veracious arithmetic of fault detection is necessary. For this purpose, the fault detective is studied about manned launch-vehicle boosting stage in this thesis.At first, the necessary of fault detection in the boosting stage is introduced, and the general methods of fault detective are described and compared. Then, the failure modes of dynamic system and control system are discussed. We emphasize on failure modes of dynamic system. -Whether detection parameters respond well to the failure modes. At last, a real time on-line fault detection algorithm is set up and realized, which mainly employs the theory of time series analysis. A key concept for fault detection is a whiteness test on the computing residual vector over the evolution time window. A standard autocorrelation whiteness test is used, where the residuals are assumed to be white, and a 99% confidence interval threshold is adopted in the autocorrelation domain. The off-nominal test then is reduced to a thresholding technique performed on the lag terms of the residuals autocorrelation. The simulation results show that the fault detection algorithm effective and applicable for boosting stage of manned launch vehicle.