Pantograph real-time high-speed vibration monitoring system with high insulating strength

Abstract

The embodiment of the utility model discloses a pantograph real-time high-speed vibration monitoring system with high insulation strength, which comprises a vibration monitoring device arranged on a pantograph and a control box arranged in a carriage, the control box comprises a power supply and an information processing board, and the vibration monitoring device and the control box are connected through an optical cable to transmit energy and complete communication. The vibration monitoring device comprises a photoelectric conversion module and a sensor for monitoring displacement and vibration; the photoelectric conversion module comprises a photocell for supplying power to the sensor and a modulator for converting data acquired by the sensor into optical signals; the control box further comprises a laser for transmitting optical energy for the photocell through an optical cable and a demodulator for receiving optical signals through the optical cable. The optical cable solves the problems of energy transmission and signal transmission under the condition of high insulating strength through the optical energy transmission technology and the optical communication technology, is low in cost and extremely high in reliability, and can be used in outdoor extreme environments.

Description

Technical Field

[0001] The utility model relates to the technical field of rail transportation, in particular to a real-time high-speed vibration monitoring system for a pantograph with high insulation strength. Background Art

[0002] With the popularity of high-speed rail and subway, the technology of using high-voltage electric energy to drive locomotives has become relatively mature. Rail transit locomotives obtain electric energy through the contact network and pantograph (collectively referred to as the pantograph network). The safety of the pantograph network system is related to whether the subway and high-speed rail can operate safely. The pantograph runs at high speed with the train. If it is subject to great external interference (such as birds hitting the pantograph body, the pantograph colliding with the loose contact network support device, etc.), it will eventually cause a serious accident of the locomotive.

[0003] The current pantograph detection methods are mainly divided into contact detection and non-contact detection. The common contact detection methods are manual detection and detection by comprehensive detection vehicles. This method not only consumes a lot of manpower costs, but also cannot achieve real-time monitoring of the pantograph. The non-contact detection method uses an installed high-speed camera to detect and evaluate the surface damage and surface defects of the pantograph through a series of advanced algorithms and means such as machine vision, but cannot effectively monitor the vibration and impact of the pantograph and the catenary. In 2015, China National Railway Corporation issued the "Interim Technical Conditions for Pantograph Video Monitoring System for EMUs" and tried to install intelligent analysis host and pantograph video monitoring system on some high-speed railways. Visual detection technology can only monitor obvious surface faults such as pantograph deformation, bow head fracture, and slide plate damage. It cannot monitor the vibration and impact information during the sliding process of the pantograph and the catenary. In fact, the contact force of the pantograph and the catenary, the life of the pantograph and the catenary, and especially the impact of hard points and hard bends can all be determined by vibration monitoring.

[0004] Due to the substantial increase in the speed of locomotive operation, the hard points existing under the same technical conditions will cause much greater impact load on the pantograph under high-speed operation than under low-speed operation, causing the pantograph to deform, and sometimes the pantograph head and pantograph body to break. The contact between the hard points and the pantograph will cause impact and vibration acceleration. Therefore, by monitoring the impact and vibration information received by the pantograph, the working status of the pantograph network can be judged, and the location of the hard points can be found and repaired accordingly.

[0005] There are three main problems in pantograph vibration monitoring: 1) The pantograph carries thousands of volts of high voltage electricity. There are a large number of passengers in the carriage. The high-strength insulation between the pantograph and the car body must be guaranteed, and no wires and cables from the pantograph end can be connected to the carriage; 2) The pantograph and the pantograph are in sliding contact, which is not very reliable when the train is running. Therefore, a huge alternating current flows through the carbon plate, thereby generating a very strong changing magnetic field, which strongly interferes with the vibration sensor; 3) In the process of raising the pantograph, lowering the pantograph, closing the switch, breaking the switch, and sudden changes in the network voltage, the electromagnetic interference caused by the arc and electrical discontinuity also poses a severe challenge to the vibration sensor. Therefore, general vibration monitoring equipment cannot be directly used for pantograph vibration monitoring.

[0006] In recent years, accelerometers made of optical fiber and MEMS galvanometers are installed under the carbon plate of the pantograph, which can meet the needs of high insulation and anti-interference. However, such products are not mature and universal, with high manufacturing costs, and their accuracy, linearity, bandwidth, and temperature characteristics need to be improved. Utility Model Content

[0007] The technical problem to be solved by the embodiments of the utility model is to provide a real-time high-speed vibration monitoring system for a pantograph with high insulation strength to realize the monitoring of the pantograph-catenary vibration while meeting the requirements of insulation and anti-interference.

[0008] In order to solve the above technical problems, the embodiment of the utility model proposes a pantograph real-time high-speed vibration monitoring system with high insulation strength, including a vibration monitoring device arranged on the pantograph and a control box arranged in the carriage, the control box includes a power supply and an information processing board, and the vibration monitoring device and the control box are connected by an optical cable to transmit energy and complete communication.

[0009] The vibration monitoring device includes a photoelectric conversion module and a sensor for displacement and vibration monitoring, the photoelectric conversion module includes a photocell for powering the sensor and a modulator for converting data collected by the sensor into an optical signal;

[0010] The control box also includes a laser for transmitting light energy to the photocell through the optical cable and a demodulator for receiving light signals through the optical cable.

[0011] Furthermore, there are three vibration monitoring devices, which are respectively arranged on both sides of the pantograph and the roof.

[0012] Furthermore, the monitoring system also includes a fiber optic distribution box, and the three-way vibration monitoring devices are connected to the fiber optic distribution box via optical cables, and then connected to the control box for communication via the fiber optic distribution box.

[0013] Furthermore, the sensor is provided with an electromagnetic shielding shell.

[0014] Furthermore, the electromagnetic shielding shell is provided with a fixing ear, and the fixing ear is provided with a screw hole for easy installation.

[0015] Furthermore, the control box also includes a storage module for storing data.

[0016] Furthermore, the control box also includes a wireless communication module for remote transmission of data.

[0017] Furthermore, the photocell and the sensor are connected via a cable.

[0018] The beneficial effects of the utility model are as follows: the utility model solves the problems of energy transmission and signal transmission under high insulation strength conditions through optical energy transmission technology and optical communication technology, has low cost and extremely high reliability, and can meet the requirements of outdoor extreme environment use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a vibration monitoring device according to an embodiment of the utility model.

[0020] Figure 2 It is an application schematic diagram of the vibration monitoring device of the embodiment of the utility model.

[0021] Figure 3 It is a three-dimensional structural diagram of the vibration monitoring device of an embodiment of the utility model.

[0022] Figure 4 It is a structural schematic diagram of a control box of an embodiment of the utility model.

[0023] Figure 5 The utility model is a schematic structural diagram of a real-time high-speed vibration monitoring system for a pantograph with high insulation strength according to an embodiment of the utility model.

[0024] Figure 6 It is a structural schematic diagram of a real-time high-speed vibration monitoring system for a pantograph with high insulation strength according to another embodiment of the utility model.

[0025] Description of Figure Numbers

[0026] Vibration monitoring device 10 , electromagnetic shielding shell 11 , photovoltaic cell 12 , cable 13 , fixing ear 14 , pantograph 20 , high voltage power grid 30 , control box 40 . DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present utility model is further described in detail below in conjunction with the drawings and specific embodiments.

[0028] In the embodiments of the present invention, if there are directional indications (such as up, down, left, right, front, back, etc.), they are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0029] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0030] Please refer to Figure 1 to Figure 6 The real-time high-speed vibration monitoring system of a pantograph with high insulation strength according to an embodiment of the utility model comprises a vibration monitoring device and a control box.

[0031] The vibration monitoring device is located on the top of the vehicle, on the pantograph, and is used to collect the impact and hard point vibration data received by the pantograph. The pantograph is in contact with the high-voltage power grid. The control box is located on the vehicle side, in the car.

[0032] The vibration monitoring device includes a photoelectric conversion module and sensors for displacement and vibration monitoring. The photoelectric conversion module includes a photocell that powers the sensor (generally composed of an accelerometer and a microprocessor chip) and a modulator that converts the data collected by the sensor into an optical signal. The electrical signal output by the sensor is converted into an optical signal by the modulator and then transmitted back to the control box through a single-film optical fiber. The control box and the vibration monitoring device are connected by an all-optical fiber, which is suitable for scenarios where high insulation strength requirements are required for the vibration monitoring device.

[0033] The sensor is preferably a common MEMS accelerometer, which is placed under the carbon slide of the pantograph. Multi-axis accelerometers deployed in the spatial direction can detect vibrations in multiple directions. MEMS accelerometers are currently widely used, the industry chain is mature, and products with various performance parameters can be purchased at low cost. Their accuracy is better than 10 -4 g products are everywhere, and the bandwidth can easily reach tens of K or more than MHz. A large number of large-scale vehicle-mounted and extreme environment application cases have proved that its reliability is extremely high and can meet the needs of outdoor extreme environments.

[0034] The sensor of the utility model preferably adopts an accelerometer sensor, but is not limited to accelerometers, and can also be other types of sensors, such as gyroscopes and inertial navigation. The monitored physical signals are not just vibrations, such as displacement, deformation, etc. The utility model adopts a photocell to power the sensor, solving the problem of energy transmission under high insulation strength conditions.

[0035] The control box includes a power supply, an information processing board, a laser, a demodulator, a storage module, and a wireless communication module. The laser uses a multimode optical fiber to transfer light energy to the photocell. The light energy is transmitted using an armored multimode optical cable, and the vibration signal is transmitted back from the vibration monitoring device using another single-mode optical fiber.

[0036] The vibration monitoring device of the utility model communicates with the control box through an optical cable, and solves the energy transmission and signal transmission problems under high insulation strength conditions through optical energy transmission technology and optical communication technology.

[0037] The vibration monitoring device can monitor three-dimensional vibration signals. In specific implementation, the vibration monitoring device has multiple channels. The vibration monitoring device is preferably three channels, which are respectively arranged on both sides of the pantograph and on the physical structure of the pantograph head base on the roof, to monitor the vibration conditions of the base and both sides of the pantograph head respectively, and eliminate the influence of the vibration of the vehicle body itself.

[0038] The utility model involves multiple sensors (accelerometer sensors), each of which outputs time series signals in real time. These signals contain multiple time domain and frequency domain characteristics such as time information, vibration information, and train running speed information. It is necessary to comprehensively determine whether there is a fault from the two dimensions of the time domain characteristics and frequency domain characteristics of the signal, and finally determine the fault point. The utility model uses short-time Fourier transform and wavelet transform to preprocess the original data. Because the multi-resolution analysis of wavelet transform has good characteristics in time domain and space domain. It can focus on any details of the analysis object by using the time domain or space bands that are gradually refined by different frequency bands of the signal. Therefore, it is particularly suitable for processing non-steady-state signals. When doing fault diagnosis, a neural network is introduced, and the original data, short-time Fourier transform data, and wavelet transform data within a certain time period are all used as inputs of the neural network. After deep learning, the neural network can effectively identify the fault mode of the pantograph through the utility model. The utility model performs real-time fault identification and detection according to the following process:

[0039] Assumption: The sampling frequency of each sensor (accelerometer sensor) is the same. f , in the interval time T The number of time series points collected in Tf, The data processing process is divided into three steps:

[0040] The first step is to intercept i The time series signal output by the sensor A i （t） of j Time series data for time period T A ij; Where i∈{1,2,...m}, m is the total number of sensors; j∈{1,2,...k}, the time of each sensor output contains k intervals T ;

[0041] The second step is to calculate the time series of each accelerometer output. A ij Perform short-time Fourier transform to obtain the vibration frequency of this time period F ij , peak height P ij ;

[0042] The third step is to calculate the time series of each accelerometer output. A ij Perform N-level wavelet transform to obtain the wavelet data vector a for this time period k and high frequency data vector b k ,{{a1},{b1},{a2},{b2}……{a N},{b N}};

[0043] The fourth step is to convert the multi-accelerometer time series information obtained in the above two steps into A ij , the time obtained by short-time Fourier transform j Time period T, frequency F ij , Spectrum Peak P ij The information is sent to the pre-trained multi-layer neural network to obtain the fault situation.

[0044] The fifth step is to construct a convolutional network and perform classification training based on the common types of bow-net faults related to vibration and impact: hard spots, cracks, fractures, eccentric wear, excessive wear, poor contact, arcing, etc.

[0045] The trained neural network can then perform real-time fault identification and detection.

[0046] As an implementation method, the monitoring system further includes an optical fiber distribution box, and the three vibration monitoring devices are connected to the optical fiber distribution box through optical cables, and then connected to the control box through the optical fiber distribution box for communication. The optical cables of the three-way photoelectric conversion modules are uniformly connected to the optical fiber distribution box, and then connected to the control box in the car through armored optical cables.

[0047] As an implementation mode, the sensor is provided with an electromagnetic shielding shell. In specific implementation, a metal shell may be used to form a Faraday shield to reduce external electromagnetic interference.

[0048] As an implementation mode, the electromagnetic shielding shell is provided with a fixing ear, and the fixing ear is provided with a screw hole for easy installation.

[0049] As an implementation manner, the control box further includes a storage module for storing vibration data.

[0050] As an embodiment, the control box further includes a wireless communication module for remotely transmitting vibration data.

[0051] As an implementation method, the photocell and the sensor are connected by a cable. Considering the volume, weight and installation issues, the photocell can be integrated inside the vibration monitoring device body. Alternatively, the photocell and the vibration monitoring device body can be divided into two parts, and an electric cable is used between the two parts.

[0052] The data processing flow of the utility model is as follows: first, digital filtering technology is used to improve the signal-to-noise ratio; then, a short-time Fourier transform is performed within a certain time end, that is, FFT is performed on all data to extract the frequency, amplitude and other characteristics of the three vibration monitoring systems; in addition, a multi-level wavelet transform is performed on this section of data. That is, the time series output by multiple accelerometers, as well as the results of short-time Fourier transform and wavelet transform of these series are used as the input of a deep learning neural network, and the deep learning neural network is used as a fusion tool for multiple sensors and multiple information to perform real-time online fault monitoring.

[0053] The utility model has the following advantages:

[0054] 1) High insulation: Data transmission and photoelectric transmission are both carried out in the form of optical fiber, which can effectively achieve electrical safety isolation between the high voltage of the line network and the vehicle end;

[0055] 2) High monitoring performance: Mature MEMS accelerometers are used as sensors, and their accuracy, linearity, bandwidth, stability, etc. are guaranteed;

[0056] 3) Low cost: The accelerometer sensor only needs one accelerometer and one microprocessor chip to collect data;

[0057] 4) Pantograph-network monitoring that is not affected by the external environment: Because it is a contact product, the pantograph can monitor the impact of the network on the pantograph and hard point monitoring as long as the locomotive is running;

[0058] 5) Real-time data analysis and display on the vehicle side: The accelerometer sensor transmits the data of the impact and hard point vibration received by the pantograph to the vehicle side through optical fiber. The vehicle side transmits the data to the display of the locomotive monitoring end through signal processing. The display can show the operating status of the pantograph, and can perform risk assessment and early warning in real time.

[0059] 6) Built-in data storage and wireless communication: The collected data can be stored in the storage module of the board on the vehicle side, without the need for other storage module units and devices, and the amount of data is extremely small, basically occupying no storage memory; the vehicle side has wireless and 4G (5G) transmission functions, and the status of the locomotive pantograph can be transmitted to the locomotive control center in real time, realizing remote monitoring.

[0060] 7) At the same time, short-time Fourier transform and wavelet transform are introduced as time-frequency analysis methods, and multi-layer neural network is used as a fusion method of multiple sensors and multiple information to enable real-time fault monitoring.

[0061] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A real-time high-speed vibration monitoring system for a pantograph with high insulation strength, comprising a vibration monitoring device arranged on the pantograph and a control box arranged on the carriage, wherein the control box comprises a power supply and an information processing board, and is characterized in that: The vibration monitoring device and the control box are connected via optical cables to transfer energy and complete communication. The vibration monitoring device includes a photoelectric conversion module and a sensor for displacement and vibration monitoring, the photoelectric conversion module includes a photocell for powering the sensor and a modulator for converting data collected by the sensor into an optical signal; The control box also includes a laser for transmitting light energy to the photocell through the optical cable and a demodulator for receiving light signals through the optical cable.

2. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 1, characterized in that: The vibration monitoring devices include three paths, which are respectively arranged on both sides of the pantograph and on the roof.

3. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 2, characterized in that: The monitoring system also includes an optical fiber distribution box. The three-way vibration monitoring devices are connected to the optical fiber distribution box through optical cables and then connected to the control box for communication through the optical fiber distribution box.

4. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 1, characterized in that: The sensor is equipped with an electromagnetic shielding shell.

5. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 4, characterized in that: The electromagnetic shielding shell is provided with fixing ears, and the fixing ears are provided with screw holes for easy installation.

6. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 1, characterized in that: The control box also includes a storage module for storing data.

7. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 1, characterized in that: The control box also includes a wireless communication module for remote data transmission.

8. The pantograph real-time high-speed vibration monitoring system with high insulation strength as claimed in claim 1, characterized in that: The photocell and the sensor are connected by cables.

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