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Li Z.,Southwest Jiaotong University | Dai H.,Southwest Jiaotong University | Tian H.,Products Quality Supervision and Test Center
Zhongguo Tiedao Kexue/China Railway Science

The influences of the orifice diameter and the pressure regulating error of proportional relief valve on the performance of semi-active damper were analyzed using the established model of semi-active damper with proportional relief valve, the skyhook damping semi-active controller system model and the dynamic model of vehicle system. The results show that the semi-active suspension system with proportional relief valve can effectively reduce carbody vibration, and with the increase of vehicle speed, the reduction of carbody vibration is much more obvious. Based on the established dynamic model vehicle system and corresponding to each speed level of vehicle, the ride comfort index of vehicle reaches a comprehensively optimal value when the damping coefficient of skyhook is 100 kN·s·m -1. Increasing the orifice diameter will slow the response of semi-active damper and minify its equivalent damping, which will lead to the undesirable traceability of the semi-active damper force to the damping force expected by controller. The vibration energy of vehicle will be greater when the vibration frequency is around 1 Hz. The pressure regulating error coefficient only has slight influence on the lateral vibration of the carbody in the range of high frequency. Source

Wang H.,Dalian CIMC Railway Equipment Ltd Company | Tian H.,Products Quality Supervision and Test Center | Dai H.,Southwest Jiaotong University
Zhongguo Tiedao Kexue/China Railway Science

The steering principle of a certain type of all low floor LRV with the independent wheel power bogie was analyzed. The contact area between the front and the rear two wheels of the independent wheel motor bogie and the track may have longitudinal creep due to the lateral movement and the yawing occurred on the front and the rear wheelsets of the bogie and may generate the longitudinal creep moment. Under the action of the longitudinal moment, the front and the rear wheelsets will produce reverse yawing and lateral movement, which consequently facilitates the independent wheel motor bogie to realize the steering function. The correctness of the longitudinal coupled creep steering principle has been proved by qualitative analysis, formula derivation and dynamic simulation. The results of both the formula calculation and the dynamic simulation agree well with the conclusions of the qualitative analysis. The longitudinal coupling can make the independent wheel power bogie steer. The mode to achieve the longitudinal coupling can be either mechanical or electrical. The steering ability of the longitudinal coupled independent wheel bogie is not as good as the conventional wheelset bogie. Source

Guo Y.,Tianjin University | Liu C.,Tianjin University | Zhu J.,Tianjin University | Liu G.,Products Quality Supervision and Test Center | And 2 more authors.
Zhongguo Jiguang/Chinese Journal of Lasers

Dynamic envelope curve is one of the key factors to be considered when defining the dynamic gauge. To accurately obtain the dynamic envelope curve is one big step in design vehicle and also an insurance against dangers in driving. Since the major way to obtain dynamic envelope curve now is by enormous calculation, a measurement system is designed for measuring dynamic envelope curve of high-speed train. Based on binocular vision, the system produces the feature using high power pulse laser, and obtains the dynamic envelope curve of the high-speed train by high-speed acquisition, process and calculation of information that reflects the excursion of train. One field calibration method is proposed to build quickly and efficiently both the position relationship between the two cameras and the transformation between center coordinate system of railway and coordinate system of measurement system. It is proved by experimental results that the measurement precision of the system can reach up to ±0.5 mm, and that the measurement of the dynamic envelope curve of high-speed train is accomplished with high reliability, which can provide useful statistics for the definition of dynamic gauge of high-speed train. Source

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