On the Alarm Causes of the EVS Sapsan Cars’ Running Stability Monitoring System
In the paper there are analyzed possible causes of applying alarm signals generated by the on-board car running stability monitoring systems (KUKH) of Sapsan high speed trains. The KUKH system software bases on the statistical analysis algorithm of lateral accelerations’ amplitudes of a bogie frame and stability loss criterion defined as in the UIC-515 Leaflet: “Lateral acceleration value of a bogie frame above the ÿ+ wheelset shall not exceed 8 m/s2 under condition that this value is fixed in more than six following each other oscillations with a frequency in the range from 4 to 8 Hz”. As a rule alarm signals were emitted with setting in ambient air temperatures below freezing point in terms of train running on the St. Petersburg - Moscow route at speeds exceeding 200 kph. There are represented alarm signals emitting data classified by train running speeds, railway line sections, train numbers and car numbers in the train sets. Based upon operating data analysis there was defined the set of possible factors having a profound effect on the alarm signals’ emission and developed methodology of experimental study aimed at revealing main causes of the system KUKh alarm actuations. Two stages of experimental study were conducted with recording bogie frames’ lateral accelerations at speeds of Sapsan trains up to 250 kph. Acceleration implementations were analyzed together with actual rail lines’ irregularities data at track sections with the largest frequencies of alarm signal application, supplied by INFOTRANS RPC. It was demonstrated that the parameters of actual irregularities under consideration (level and frequency content) did not present any troubles in the part of causing dangerous accelerations. Based on analysis of experimental data it has been established that technical condition of the EVS Sapsan car underframes, supported with existing maintenance system cannot exert negative influence on the cars’ stable running. It is stated that accelerations processing algorithm employed by the KUKh system software does not comply with the provisions of the normal documents in force. Based on the investigation results there have been formulated system KUKh reprogramming proposals.