Research On Rapid Ranging Technology Of High-speed Train Dynamic Posture Measurement System

In recent years, the rapid development of high-speed railway makes a higherdemand on the security and stability of the trains, which makes the task ofmeasurement more challenging. The measurement system of high speed train dynamicposture is a detection system to measure the posture and obtain the offset and theinclination angle of the operating high speed trains. This paper introduced the designof position sensors of the measurement system of high speed train dynamic posture,which plays an important role in range positioning and obtaining the train speedinformation. According to the position and speed information providing by the sensor,the posture measurement system can calculate the posture changes of differentsections when they pass through the measurement system.In this paper, the method of pulsed laser ranging is chosen to design the positionsensor, which is based on the analysis of the train positioning principle of speed andposition sensor. After a detail analysis on the compositions of sensor, ranging principleand each module of the system, the device is selected and the hardware module isbuilt. Finally, a prototype is produced. The design of sensor is divided into thefollowing four modules: the laser transmitter module, the laser receiver module, thetimer module and the control module. In the transmitter module, pulse laser of whichthe repetition rate is about 20K, the pulse width is less than 100ns, and the peak poweris 75W can be launched by the selection of the device and the design of driver circuit.In the receiver module, the cascade of the transimpedance preamplifiers and the twolevel voltage main amplifier makes it possible for the receiver channel to have largeenough amplification function to the small signals under the condition of ensuring thebandwidth of the system. In the timer module, a new time identification technology isused to reduce the drift error and the false trigger rate of the system, and also, theintroduction of high-precision timing chip of TDC-GP2 makes the measurementresolution achieve cm-level. Optical system is designed for the transmit and receivechannels in this paper, which can increase the range of the systems and reduce thenoise of background light effectively. Finally, the preliminary experiments are madeon the prototype in this paper which analyzed the precision and linearity of themeasurement results. These experiments show that the system is stable, high-precision, and satisfied for the measurement requirements.