Identification of the catenary structure wavelength using pantograph head acceleration measurements

IEEE Trans. Instrum. Meas.

Núñez

et al. 2019

Self Cite

The condition-based maintenance of high-speed railway catenary is an important task to ensure the continuous availability of train power supply. To improve the condition monitoring of catenary, this paper presents a novel scheme to detect catenary local irregularities using pantograph head acceleration measurements. First, a series of experimental inspections is carried out in a section of the Beijing-Guangzhou high-speed line in China. The time intervals between the inspections are shortened from the traditional six months to about 40 days, which enables monitoring the short-term degradation of local irregularities. Then, based on the wavelet packet entropy, an approach is proposed to detect local irregularities with different scales in length. Criteria for identifying and verifying the local irregularities are established based on the gradient and repeatability of entropy from multiple measurements. Results from the experimental inspections show that different scales of local irregularities can be detected by the proposed scheme. By using frequent inspections, local irregularities can be effectively verified after about seven inspections. The spatial distribution of local irregularities is found to be closely related to the catenary structure. These findings provide valuable information to deploy the scheme for a railway network.

Section: B Preprocessingmentioning

confidence: 99%

Section: B Preprocessingmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Entropy-Based Local Irregularity Detection for High-Speed Railway Catenaries With Frequent Inspections

Wang

IEEE Trans. Instrum. Meas.

Núñez

et al. 2019

Self Cite

“…Some studies have focused on improving the catenary dynamic response measurement methods, which include the contact-type and noncontact methods. The contacttype sensors have been widely used to determine the catenary acceleration under different impacts [20,[25][26][27]. Further, the noncontact methods based on photogrammetric devices have been established to measure the catenary uplift without interrupting the railway operation [28,29].…”

Section: Introductionmentioning

confidence: 99%

Vibration Measurement and Wave Reflection Analysis in an Electrified Railway Catenary Based on Analytical Methods

Duan

IEEE Trans. Instrum. Meas.

Song

et al. 2021

Self Cite

The wave propagation property of the catenary directly affects the pantograph-catenary interaction performance. Specifically, wave reflection and transmission occurring at waveguide discontinuities, particularly at dropper junctions, directly impact the pantograph-catenary interaction performance. In this study, wave reflection occurring at the dropper junctions are investigated using both analytical and experimental approaches. First, a partial catenary model is established to analyze the catenary wave propagation by considering the wave reflections at the dropper junctions. Result indicates that the wave reflection in the contact wire (CW) affects the contact performance more significantly than that in the messenger wire. Two types of experimental tests are performed to analyze the wave reflection in the catenary-single CW and full-scale catenary tests. An analytical method considering back-and-forth reflections between the adjacent droppers is proposed to identify the actual reflection coefficients and extract the wave components from the measured data. The single CW test result shows that the dropper mass has a negligible influence on the wave reflection. The fullscale catenary test result indicates that the catenary reflection coefficient obtained from the measured data can match the design value with an acceptable error using the proposed method. Moreover, the measured data can be decomposed into wave components with different reflection orders, in which less energy is centered in the higher-reflection-order component. The proposed methods have been justified effective in reflection coefficient identification for the actual catenary structure.

“…Currently, there are two main methods for pantograph–catenary condition measurement: Non-contact methods based on image processing and contact-type schemes based on sensors installed in the system. In previous years, contact-type schemes have been widely used in railway condition detection, such as contact force collection [ 20 , 21 ] and acceleration collection [ 22 , 23 ]. However, these approaches require parts of the measurement system to be installed on the catenary structure, which means that the railway traffic will be interrupted and measurement will take a more substantial amount of time.…”

Section: Introductionmentioning

confidence: 99%

A Siamese Network-Based Non-Contact Measurement Method for Railway Catenary Uplift Trained in a Free Vibration Test

Duan

Zhai

et al. 2020

Sensors

Self Cite

The vibration of the catenary that is initiated by the passing pantograph has a direct influence on the pantograph–catenary contact performance. Monitoring the dynamic uplift of the catenary can help inspectors to evaluate the railway operation conditions and investigate the mechanism of pantograph–catenary interaction further. In this paper, a non-contact measurement method based on the deep leaning method is proposed to monitor the real-time vibration of the catenary. The field test for the catenary free vibration is designed to validate the method’s performance. The measurement method is developed based on the fully convolutional Siamese neural network, and the contact wire is taken as the tracking target. To reduce the recognition errors caused by the changes in the shape and grayscale of the moving contact wire in images, the class-agnostic binary segmentation mask is adopted. A developed down-sampling block is used in the neural network to reduce the image feature loss, which effectively enhances the recognition effect for the catenary vibration under variable lighting conditions. To validate the performance of the proposed measurement method, a series of field tests of catenary free vibration were conducted under various lighting conditions and different excitations, and the recognition results were compared with traditional target tracking methods. The results show that the proposed method performs well for catenary vibration identification in the field test. Additionally, the uplift data extracted from the identified images agree with the numerical results, and also help to further investigate the wave propagation and damping characteristics in the catenary structure.