Design And Implementation Of Rail Weld Straightness System

Recently, with the rapid development of high-speed railway in China and the increasing of train speed, higher requirements for rail precision are put forward in order to guarantee transportation more efficiently and safely. Moreover, the flatness of rail welding head is one of the key factors to affect the precision of the rails, so it is crucial to get high precision flatness testing systems.Nowadays, the following two kinds of detection methods are mainly adopted in China. One method is the traditional method for detecting with ruler plus feeler gauge which has long measuring time and low precision, cannot satisfy the high-precision and large-scale production demands now. The other method is the E-ruler which mostly depends on import, E-ruler can provide high precision measurement result but it is expensive, in addition the closed architecture type is impossible for functional extension and upgrade. Therefore, it has great significance that to research and develop independently a multifunctional, high precision and easily extensible rail flatness detection system.This paper implements a rail welding head flatness detection system by which the users can carry out flatness detection for the produced rails and screen out the unqualified rails to be polished, according to the testing results.This paper first analyzes the current domestic and overseas researches on rail flatness testing system, then it presents a design scheme of rail welding head flatness detection system, combining with “one key measure” demand of the domestic rail welding base on detection equipment. With IPC as the core, combined with high-precision sensors and multifunctional data acquisition card, the automatic detection and determination of flatness within 500 mm of the welding head is achieved. Software design uses modular programming and implements data control, data acquisition, data processing, data storage and data display module step by step. The software design employs the interrupt technique of USB-4751 and MFC multithreading technology to realize real-time data acquisition without loss. Furthermore, it adopts database to store and manage large amounts of data. Moreover, using the least squares method, limiting filtering and weighted average filtering algorithm, the measurement error is reduced. And the automatic determination of curve flatness measurement is finished according to the Ministry’s the flatness standards and slash determination principles. This paper has the following innovations:(1) Testing system achieves a "one-key measurement", which solves the defects of the traditional flatness testing system, like the needs of technical staff participation and personnel error.(2) Testing system implements a "multidimensional measurement" so it solves the problem that the one-sided information achieved by traditional system.A large number of experiments are conducted on the designed rail welding head flatness testing system in this paper. Results show that the system can satisfy the measurement requirements of the welded rail base, which contains "a key measure," "multi-dimensional collection" and "high precision". And this system has good extensibility, stability, and interactivity.