Overloaded Freight Train Super Partial Load Condition Monitoring Systems Research And Application

As representation of advanced level and important development direction of world freight transportation nowadays, heavy load train is an effective measure of enhancing transportation capacity and efficiency, and provides strong support for the rapid development of national economy in China. In recent years, with the wide-range increase in speed of trains, security accidents happen occasionally. After analyzing those running accidents of trains at high speed, ministry of railway considers that over load and imbalanced are the important factors leading to running off rail of trains and menacing the security of operation. In order to ensure the security, we must strengthen the safety monitoring of overload and imbalanced load status. However, the existing equipments mostly were installed on the fixed station to detect the status of running trains. This ways can’t detect the phenomenon of over load and imbalanced causing by turning, speed changing and inclination in time. It has certain limitations and backwardness and may be a significant impact on train safety. So, studying the on-line detecting method and designing the new vehicle-mounted type monitoring system provide important practical significance and good application value.Based on heavy load train, the vehicle-mounted type monitoring system, the on-line detecting method of overload and imbalanced status, the signal characteristics and data processing algorithms are researched in this paper. The major innovation research work includes:(1) Based on the requirements of timely detection, efficient operation and quasi-real time, taking into account the detecting notes’ functional requirements, the paper designs the integral architecture of the vehicle-mounted type monitoring system based on WSN (wireless sensor network) and provides the specific software and hardware solutions;(2) Based on analyzing the transmission of bogie load and setting up the mechanical model of the Spring Group with Two-Stage Stiffness, a on-line detecting method of overload and imbalanced status is studied, which can realize real-time detection. According to analysis of the characteristic of vibration of weighing system, the characters of testing signal are obtained.(3)This paper introduces a new and self-adaptable time serials analysis method——HHT(Hilbert-Huang Transform), and it was used to extract the characteristic signal. The practicability and efficiency of EMD is tested by comparing traditional least square method and wavelet method with EMD. But the local mean estimation isn’t precision and the end effects exist in the conventional EMD, so, a improved algorithm is introduced. It can help to reduce the computing time, improve the efficiency and reduce the end swing.(4) Finally, we have developed a prototype of the vehicle-mounted rail freight vehicle dynamics monitoring system, and fix it on a special long rail train of the Guangzhou Railway Group, we use the EMD method to process the testing signals, and the data are fitted to curves by means of the least-square method based on LABVIEW8.5.