高精度火箭橇试验轨道随机不平顺分析

Stochastic Irregularity Analysis on High Accuracy Rocket Sled Test Track

对实测高精度火箭橇试验轨道随机不平顺功率谱密度(PSD)进行B样条插值,得到拟合用PSD平均曲线。对此曲线采用最小χ方回归与粒子群优化算法,得到了指数函数形式的PSD函数参数值。基于PSD进行频率采样,利用Monte Carlo法模拟得到随机相位,然后利用Blackman-Turkey法模拟得到试验轨道空间域内的不平顺大小。分析与模拟结果表明:高精度火箭橇轨道随机不平顺具有低频、低幅值和低功率特性,随机不平顺对数PSD值随频率的增加而趋于稳定值。

Stochastic irregularity power spectrum density(PSD) data surveyed from high accuracy rocket sled test track is interpolated with B-spline to gain PSD average curves for curve fitting.Parameter values of exponential form PSD function are calculated by minimizing Chi-square value regression and particle swarm optimization.Based on the PSD function, frequencies are sampled and stochastic phases are simulated by Monte Carlo method, then test track irregularity magnitudes in space domain are gotten by Blackman-Turkey method.The analysis and simulation results show that high accuracy rocket sled test track stochastic irregularity has characteristic of lower frequency, lower amplitude and lower power, its common logarithm PSD tends to a steady value as frequency increasing.