航空地面电源车备件供应能力建模仿真研究

备件供应一定程度上制约着航空地面电源车的保障能力。针对现阶段备件供应能力缺乏评判手段的问题,从实际保障过程出发,考虑任务执行过程中的动态因素,以备件延期交货量和备件短缺风险为评价指标,运用数理统计、蒙特卡洛法、排队论和计算机仿真技术,建立了包含备件需求、备件库存与周转和指标计算在内的仿真评价模型,并对模型进行了实例检验。实例表明该模型合理可信,能够实现对各评价指标的仿真。仿真结果不仅能够反映航空地面电源车的备件供应能力,还可为备件的优化配置提供决策参考。     

A novel de-noising method based on discrete cosine transform and its application in the fault feature extraction of hydraulic pump

Aiming at the existing problems of discrete cosine transform (DCT) de-noising method, we introduce the idea of wavelet neighboring coefficients (WNC) de-noising method, and propose the cosine neighboring coefficients (CNC) de-noising method. Based on DCT, a novel method for the fault feature extraction of hydraulic pump is analyzed. The vibration signal of pump is de-noised with CNC de-noising method, and the fault feature is extracted by performing Hilbert-Huang transform (HHT) to the output signal. The analysis results of the simulation signal and the actual one demonstrate that the proposed CNC de-noising method and the fault feature extraction method have more superior ability than the traditional ones.