Rail Track Surface Image Acquisition and Positioning

2013 ◽  
Vol 278-280 ◽  
pp. 1143-1147
Author(s):  
Liang Sun ◽  
Jun Zhang ◽  
Zhe Chen ◽  
Long Guo ◽  
Jia Ge ◽  
...  

Rail track surface detection system was constructed to detect the rail track surface. The mismatch between the train speed, rail track location and camera trigger speed was solved during the real-time acquisition process about the rail track using optical encoder and GPS module. In our system, optical encoder was used to reflect the train speed and output pulse to externally trigger the line scan high-speed camera exposure. At the same time, another pulse of optical encoder was transmitted to the computer to save the GPS location information. So the rail track images are saved with the track location information.

2013 ◽  
Vol 278-280 ◽  
pp. 856-860
Author(s):  
Long Guo ◽  
Jun Zhang ◽  
Zhe Chen ◽  
Liang Sun ◽  
Jia Ge ◽  
...  

Rail track surface defects detection is an important part of the monitoring of railroad safety. In this paper, rail track images obtained by detection system of rail track surface image are processed. Firstly, the Hough transform is applied to process the images of the track surface to locate and extract the image of the track surface, which overcomes the influence of incline and unfixed width of track surface images caused by vehicle vibration. Secondly, improved Sobel operator and area filter are used together to extract track surface defects from the original images. Finally, the defects images are classified based on circularity and length-width ratio of minimum enclosing rectangular of defects images.Results of experiments show that the algorithm can identify and classify the defects images of track surface. The minimum detection region in rail track surface is 0.0068 cm2.


2013 ◽  
Vol 321-324 ◽  
pp. 1145-1149 ◽  
Author(s):  
Kun Lin Lü ◽  
Jun Zhang ◽  
Guang Yu Dai ◽  
Liang Sun ◽  
Long Guo ◽  
...  

The first step of track surface detection based on contactless optical detection is to obtain the surface image. This paper introduces a vehicle-mounted image collecting system base on area-array camera. This system avoids image morphing and edge deformation of system base on linear-array camera.Camera could works in both frequently flash and persistent bright without influence image collecting and will not miss information of the rail track surface when vehicle keeps the speed of 342Km/h. The exposure time should be chosen according to railcar speed and maximum speed.


2013 ◽  
Vol 321-324 ◽  
pp. 1017-1020
Author(s):  
Guang Yu Dai ◽  
Jun Zhang ◽  
Kun Lin Lü ◽  
Long Guo ◽  
Liang Sun ◽  
...  

In the field of detecting for defects of railroad track surface, computer vision method for detection has been widely used. An online real-time image processing system for defects of railroad track surface is introduced in the paper. Results show that: if the number of pixels in each railroad track surface image is 512×240, the train speed can be 50 Km/h while the image processing system can real-time detect the railway track surface defects, the number of pixels in in each railroad track surface image is 320×250, the train speed can be 100 Km/h while the image processing system can real-time detect the railway track surface defects.


Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5279
Author(s):  
Dong-Hoon Kwak ◽  
Guk-Jin Son ◽  
Mi-Kyung Park ◽  
Young-Duk Kim

The consumption of seaweed is increasing year by year worldwide. Therefore, the foreign object inspection of seaweed is becoming increasingly important. Seaweed is mixed with various materials such as laver and sargassum fusiforme. So it has various colors even in the same seaweed. In addition, the surface is uneven and greasy, causing diffuse reflections frequently. For these reasons, it is difficult to detect foreign objects in seaweed, so the accuracy of conventional foreign object detectors used in real manufacturing sites is less than 80%. Supporting real-time inspection should also be considered when inspecting foreign objects. Since seaweed requires mass production, rapid inspection is essential. However, hyperspectral imaging techniques are generally not suitable for high-speed inspection. In this study, we overcome this limitation by using dimensionality reduction and using simplified operations. For accuracy improvement, the proposed algorithm is carried out in 2 stages. Firstly, the subtraction method is used to clearly distinguish seaweed and conveyor belts, and also detect some relatively easy to detect foreign objects. Secondly, a standardization inspection is performed based on the result of the subtraction method. During this process, the proposed scheme adopts simplified and burdenless calculations such as subtraction, division, and one-by-one matching, which achieves both accuracy and low latency performance. In the experiment to evaluate the performance, 60 normal seaweeds and 60 seaweeds containing foreign objects were used, and the accuracy of the proposed algorithm is 95%. Finally, by implementing the proposed algorithm as a foreign object detection platform, it was confirmed that real-time operation in rapid inspection was possible, and the possibility of deployment in real manufacturing sites was confirmed.


2021 ◽  
pp. 136943322110032
Author(s):  
Lin Ma ◽  
Wei Zhang ◽  
Steve C.S. Cai ◽  
Shaofan Li

In this paper, the dynamic amplification factors (DAFs) of high-speed railway continuous girder bridges are studied. The vehicle-bridge interactions (VBIs) of 13 concrete continuous girder bridges with spans ranging from 48 to 130 m are analyzed, the influences of the train speed, the train marshalling and the bridge fundamental frequency on the DAF are investigated, and the DAF design standard for high-speed railway bridges is discussed. The results indicate that for the continuous beam bridge whose fundamental frequency is less than 3.0 Hz, the maximum DAF is no more than 1.15; while for the bridge examples with a fundamental frequency larger than 3.0 Hz, the maximum DAF reaches 1.25 because the resonance occurs at high train speed. The empirical formulas of the DAFs in the Japan Railway Technical Research Institute (JRTRI) code could provide a conservative estimation of the DAFs of high-speed railway continuous bridges.


2012 ◽  
Vol 542-543 ◽  
pp. 828-832 ◽  
Author(s):  
Jing Fang Yang ◽  
Xian Ying Feng ◽  
Hong Jun Fu ◽  
Lian Fang Zhao

Tire dynamic balance detection plays an important part in tire quality detection area. This paper uses the two-sided balance method to obtain the unbalance of the tire. According to the engineering practice, builds kinetic model and then introduces the calculating principle and operating procedures. In order to accurately determine the influence coefficient, a calibration method without tire is put forward. Further more, this new method is able to eliminate the unbalance caused by non-quality factors to some extent. But this method is presented based on the relative position invariance of the upper rim and lower rim, even both of them are under high-speed rotation situation. Finally, the experimental data acquired from both of the two methods are compared. The calibration method without tire is proved to be more feasible, efficient and accurate.


2013 ◽  
Vol 712-715 ◽  
pp. 2323-2326
Author(s):  
Xing Guang Qi ◽  
Hai Lun Zhang ◽  
Xiao Ting Li

This paper presents an on-line surface defects detection system based on machine vision, which has high speed architecture and can perform high accurate detection for cold-rolled aluminum plate. The system consists of high speed camera and industrial personal computer (IPC) array which connected through Gigabit Ethernet, achieved seamless detection by redundant control. In order to acquire high processing speed, single IPC as processor receives from and deals with only one or two cameras' image. Experimental results show that the system with high accurate detection capability can satisfy the requirement of real time detection and find out the defects on the production line effectively.


Author(s):  
Minling Feng ◽  
Chaoxian Wu ◽  
Shaofeng Lu ◽  
Yihui Wang

Automatic train operation (ATO) systems are fast becoming one of the key components of the intelligent high-speed railway (HSR). Designing an effective optimal speed trajectory for ATO is critical to guide the high-speed train (HST) to operate with high service quality in a more energy-efficient way. In many advanced HSR systems, the traction/braking systems would provide multiple notches to satisfy the traction/braking demands. This paper modelled the applied force as a controlled variable based on the selection of notch to realise a notch-based train speed trajectory optimisation model to be solved by mixed integer linear programming (MILP). A notch selection model with flexible vertical relaxation was proposed to allow the traction/braking efforts to change dynamically along with the selected notch by introducing a series of binary variables. Two case studies were proposed in this paper where Case study 1 was conducted to investigate the impact of the dynamic notch selection on train operations, and the optimal result indicates that the applied force can be flexibly adjusted corresponding to different notches following a similar operation sequence determined by optimal train control theory. Moreover, in addition to the maximum traction/braking notches and coasting, medium notches with appropriate vertical relaxation would be applied in accordance with the specific traction/braking demands to make the model feasible. In Case study 2, a comprehensive numerical example with the parameters of CRH380AL HST demonstrates the robustness of the model to deal with the varying speed limit and gradient in a real-world scenario. The notch-based model is able to obtain a more realistic optimal strategy containing dynamic notch selection and speed trajectory with an increase (1.622%) in energy consumption by comparing the results of the proposed model and the non-notch model.


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