Research On Measurement Technology Of Contact Rail Geometric Parameters Based On Multi Laser Sensor

In recent years,subway construction has been developed rapidly.In the subway power supply system,The contact rail has been widely used due to it's low construction cost,high power supply reliability,convenient construction and installation,low maintenance workload,and small impact on the urban landscape.The normal working condition of the contact rail is an important prerequisite for the safe and reliable operation of the subway.When the position of the contact rail changes,the power supply of the subway vehicles will be affected.It even caused the current receiving device to collide with the contact rail,which seriously threatened the safe operation of the subway.Because the contact rail power supply system is mostly used in long intervals,the efficiency of manual detection is low,and the accuracy of detection cannot be guaranteed,designing an automatic detection system to improve the efficiency and accuracy of contact rail geometric parameter detection is of great significance in providing data support for contact rail maintenance and ensuring the safe and reliable operation of the subway.This paper based on the non-contact measuring method and the working principle of the laser sensor research.Based on laser sensor,the study designed the synchronization trigger module,establish a non-contact contact rail geometric parameter detection system,the system includes a laser sensor module for collecting data,a synchronous trigger module,a power module,an A/D conversion module,a microcontroller control module,etc.In the determination method of the track centerline,two different schemes using the ACR-LDS131 laser displacement sensor and the Gocator 2130 three-dimensional laser sensor were studied.In the detection system,first of all,the data collected by the laser sensor must be preprocessed,and the pre-processed data can be used to reconstruct the contour curves of the inner side of the rail and the surface of the contact rail.Then,through the feature point extraction algorithm designed in this paper,The feature points on the railand the contact rail are extracted,and then,based on the least-square method to design the gauge calculation method,The track gauge value is calculated by the feature point coordinates of the track and the algorithm,the position of the track centerline is determined by the calculated track gauge value,and then on the basis of the feature point coordinates through the contact rail and the formula of contact rail geometry parameter to calculate the contact rail horizontal distance and vertical distance,Complete the detection of the geometric parameters of the contact rail.Finally,this paper designs the software of the contact rail geometric parameter detection system.PC software mainly controls the sensor to collect data,and processes the collected data,and extracts the characteristic points,draws the contour curve and data storage,and other functions.It is convenient for the staff to use this system to detect the geometric parameters of the contact rail.The contact rail geometric parameter detection platform was built in the laboratory and the system was tested.The experimental results show that the absolute error of the geometric parameters of the contact rail calculated by the detection system is within 5mm,which verifies that the detection system has good accuracy and stability.