Research Of Onboard Railway Complete Profile Measurement System

With the high-speed development of urban transit, fast complete profile measurement technology is required for the new and existing railway lines. Complete profile measurement of lines is the basic condition of safe and rapid railway operation. The measurement parameters include clearance limit for overhead contact wire, ballast bed section, contour of bridge and tunnel, distance of adjacent line, and other clearance size. These parameters play an important role in train safe and rapid running.Onboard railway complete profile measurement system was designed based on dynamic non-contact measurement method in this thesis. Two high-speed laser range scanners which can scan 180 degree were used to collect complete profile data. The transition from center coordinate of laser to track reference coordinate was realized through calibration system based on two-dimension method. Vehicle vibration was compensated using dynamic inertial reference system, which used displacement sensor and gyroscope. At the same time, the precision of system was improved. Train position and mileage amendment were completed, using rotating speed sensor and point-laser AR4000. Out-of-gauge point was estimated and out-of-gauge image was captured with image capture system.Overall scheme and realization method of railway complete profile measurement system, complete profile measurement and calibration arithmetic were expatiated, as well as, dynamic compensation scheme, speed and position measurement and amendment method, out-of-gauge image capture technique were argued in this thesis. Scheme design and realization of data acquisition card found on FPGA were mainly introduced. IP core design in FPGA was realized using VHDL language, and function and timing simulation of every functional module were presented. Furthermore, composition of synchronize signal and application of synchronize acquisition system were described. PCI interface circuit was proposed. And its driver program was compiled in VC++6.0. The system experiment in library and application in FuZhou were introduced. At last, error analysis of measurement system was done.In filed experiment, the measurement system was installed in normal operation vehicle. Its advantages contain:installation convenience, anti-interference, such as rain, storm and daylight, high measurement precision. it can accommodate track traffic environment.