Method of Unequally Spaced CCAR(2) Series with Double Roots for Pressure-Time Trace Analysis

摘要

The accurate analysis and prediction of pressure-time trace is one of the keys to successful rocket motor design. But the unequally spaced correlation coefficient stationary series is frequently met in the test data of pressure-time trace, which is different from the traditional time series in the characteristics of unequally spaced sampling and non-stationary. The traditional time series analysis method is only suitable for equally spaced data. Approximate analysis methods for unequally spaced data, such as interpolation methods, may result in terrible error. The analysis method for correlation coefficient stationary series with unequally spaced data has been established. In this present paper, the analysis method for unequally spaced correlation coefficient AR(2) (or CCAR(2)) series with double roots is presented. By the method, the mean function, the variance function and the correlation coefficient function of unequally spaced CCAR(2) series with double roots can be calculated with high precision, and the corresponding results are also given in detail. This method is used to analyze the pressure-time trace of the KDX-002 static test of the Kappa-DX rocket motor.