Analysis of Consistency of Ride Quality Evaluation Algorithm for Railway Vehicles

Abstract:

The evaluation of ride comfort of railway vehicles related to vibration is mainly based on the standard of ISO 2631-1， UIC 513 and GB/T 5599. Among them， the Sperling index algorithm in the GB/T 5599—2019 specification widely used in China shortens the sampling time from 18–20 s in the 1985 version to 5 s， the same as the UIC513 standard， which results in an increase in the index result from the same test data. The algorithms of the three standards for ride quality or ride comfort were analyzed with the measured data and the simulation data to study the index consistency about the sampling time and the mechanism. Then the frequency resolution was used to quantify the instability of the index results caused by the weighted spectrum with non-square value due to the mismatch of time-frequency energy conversion. Based on this， the corresponding correction algorithm of ride quality consistency is proposed. The results show that the algorithms in the standards ISO 2631-1 and UIC 513 are based on the energy correspondence of time-frequency domain conversion of vibration data， whose ride comfort results are not related to the sampling time length. However， the cube value algorithm in the frequency domain adopted in GB/T 5599 does not meet the energy consistency principle. With the influence of the fence effect and energy leakage， shortening the sampling time increases the amplitude of the acceleration spectrum， which leads to an increase in the ride quality index in turn. The consistency correction algorithm of ride quality index based on the unified frequency resolution proposed in this paper was validated by the dynamic simulation data， providing a theoretical basis for improving the vibration comfort related algorithms and evaluation limits in vehicle dynamics analysis and testing.

Key words:railway vehicle;ride quality;frequency resolution;Sperling index;index consistence