Research And Development Of The Detection System Of Train Track Geometry Based On Linux

The track geometric state inspection system(track inspection system)is a necessary inspection equipment which is used for the construction,operation and maintenance of highspeed railway tracks.The traditional track inspection system with optical measurement methods and inertial measurement(INS)both adopt the hardware and software architecture of SCM system,which have some defects such as low sampling frequency,small data throughput and poor hardware reconfiguration.It often suffers from delayed data processing and downtime when more sensor devices are incorporated.In order to improve the sampling frequency,data throughput and hardware reconfiguration of the track inspection system,and realize the fast real-time acquisition of the geometric parameters of the train track,a new design scheme of the geometric parameters of the train track was proposed based on Linux in this paper,and the key technologies in the design of the track geometry state inspection system were studied.The main research contents of this paper are as follows:(1)According to the parameter definition and detection requirements of the internal and external geometric parameters of the track,the overall design scheme of the track inspection system was determined,and the selection of sensors is completed.(2)The space and time synchronization is the prerequisite for multi-sensor data fusion.In order to ensure sensor data Fusion precision,a time synchronization acquisition scheme was proposed for multi-sensor data based on synchronization pulses while performing spatial synchronization of multi-sensor data through coordinate transformation in this paper.(3)In the multi-sensor data fusion of the track inspection system,aiming at the deficiency of traditional multi-wavelet decomposition and reconstruction in noise reduction,a new threshold function was constructed on the basis of traditional wavelet threshold quantization processing,and the proportional factor in the threshold function was adjusted to suppress the influence of random errors in IMU.(4)Aiming at the limitations of the hardware architecture of the existing track inspection system,a new track inspection system was proposed which is based on the dual-processor hardware architecture.Colibri i MX6 S computer module and STM32-SCM are selected as the core control unit of the new track inspection system.Following the modular design concept,the hardware circuit of the whole track inspection system was divided into multiple submodule that mainly includes power module,data acquisition module,network module,storage module,OLED display module and key module,etc.(5)Around the embedded Linux operating system,the overall software of the track inspection system was designed and debugged.The software design of the new track inspection system mainly includes three parts: the device driver program which communicates with the underlying hardware,the QT application program of data acquisition,storage and transmission at the back end,and the SCM program of data acquisition at the front end.(6)Completed the performance test and measurement test of the new track inspection system;By using the open source performance testing tool in embedded Linux system,the parameter indicators of each functional module of the track inspection system were tested,and the correctness of the new track inspection system was verified.By comparing the measurement results of the new track inspection system with the existing products,it can be seen that the inspection accuracy of the new track inspection system can meets the measurement requirements of the geometric parameters of the train track.To sum up,the new track inspection system designed in this paper provides a reference case for the precise measurement of the unattended track geometry state inspection system,and provides a solution for the concurrent processing of large data in the measurement acquisition system.