CN114298087A - Attention mechanism-based hybrid CNN-LSTM dropper anomaly detection method - Google Patents

Attention mechanism-based hybrid CNN-LSTM dropper anomaly detection method Download PDF

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CN114298087A
CN114298087A CN202111469577.3A CN202111469577A CN114298087A CN 114298087 A CN114298087 A CN 114298087A CN 202111469577 A CN202111469577 A CN 202111469577A CN 114298087 A CN114298087 A CN 114298087A
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dropper
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attention mechanism
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CN114298087B (en
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张学武
张珹
田升平
聂晶鑫
李飞
丁正全
郑筱彦
刘鹏
宫衍圣
李晋
刘刚
隋延民
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China Railway First Survey and Design Institute Group Ltd
China Railway Construction Corp Ltd CRCC
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China Railway Construction Corp Ltd CRCC
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Abstract

The invention discloses a mixed CNN-LSTM dropper abnormality detection method based on an attention mechanism, belonging to the technical field of automatic detection of electrified railways. The invention provides a mixed CNN-LSTM dropper abnormality detection method based on an attention mechanism, which comprises a one-dimensional convolution part and an LSTM part, wherein the one-dimensional convolution part extracts local space characteristics of signal data, the LSTM part extracts long-term dependence characteristics of the signal data, the attention mechanism is further introduced, important channel signal information influencing abnormality detection is focused, and finally abnormality detection of a catenary dropper is realized. The invention fully considers the characteristics of the vibration acceleration signal data of the contact net, improves the deep learning network, has higher detection precision and stronger robustness on the breakage of the dropper of the contact net, and thus improves the working efficiency of dropper maintenance and repair.

Description

Attention mechanism-based hybrid CNN-LSTM dropper anomaly detection method
Technical Field
The invention belongs to the technical field of automatic detection of electrified railways, and particularly relates to a hybrid CNN-LSTM dropper abnormality detection method based on an attention mechanism.
Background
The pantograph-catenary system formed by the contact network and the pantograph is an important factor influencing the stable current collection of the electric locomotive, the contact network is laid in the open along a high-speed line, is influenced by natural factors such as external environment, climate and the like and the huge impact action of the pantograph for a long time, is a weak link of the electrified railway, and the faults of the pantograph-catenary-system account for more than 90% of the total number of the traction power supply system. The dropper is a key part of a contact net, is a bridge between a contact line and a carrier cable, is easy to break down under the action of external force and external severe environment, and seriously influences the running safety of a train.
The traditional contact net dropper abnormity detection is mainly a manual inspection method, and a technician is relied on to check on the spot or check a shot image, so that the defects of high detection cost, high false detection rate, poor timeliness and the like are overcome, and the high requirement of safe operation of a train is difficult to meet. Therefore, how to utilize machine learning and artificial intelligence technology to realize the detection of string hanging abnormity on vibration signal data acquired by the high-speed rail 6C system is a technical problem which is very important for the railway department. The early detection of the catenary dropper abnormality is mainly based on a signal processing technology, the characteristics of vibration acceleration signals collected by a high-speed rail 6C system are extracted, fault recognition is carried out after the characteristics are extracted, and the core is data characteristic extraction and pattern recognition classification. The manual feature extraction needs to analyze the operation mechanism of the system, select a proper signal analysis method, and if the selection is not proper, important features may be lost, so that the final diagnosis accuracy is low. The method overcomes the defect of manual feature extraction, and has important research value in realizing the intelligent detection of the end-to-end dropper.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a mixed CNN-LSTM string hanging abnormity detection method based on an attention mechanism. And an attention mechanism is further introduced, important channel signal information influencing the abnormity detection is paid attention to, and finally the abnormity detection of the catenary dropper is realized.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
the method comprises the following steps:
a hybrid CNN-LSTM dropper anomaly detection method based on an attention mechanism, the method comprising:
step 1: acquiring an acceleration signal, and mounting an acceleration sensor on each span of carrier cables and contact lines; acquiring horizontal and vertical acceleration signal data of each acceleration sensor under 4 working conditions that a first dropper is broken, a midspan dropper is broken, the midspan dropper and the first dropper are broken simultaneously, the first dropper is broken and the midspan dropper is not broken under the action of pulsating wind;
step 2: building a deep learning environment, and installing a Keras library based on a deep learning framework TensorFlow on a server;
and step 3: constructing a mixed CNN-LSTM model based on an attention mechanism;
and 4, step 4: training a mixed CNN-LSTM model based on an attention mechanism;
and 5: and acquiring vibration acceleration signal data of the contact network in real time, inputting the trained attention-based hybrid CNN-LSTM dropper abnormity detection model, performing fault diagnosis, and judging whether the dropper is broken.
In the scheme, the step 3: constructing a mixed CNN-LSTM model based on an attention mechanism:
step 3.1: and constructing an attention module of the mixed CNN-LSTM model based on an attention mechanism. Firstly, performing one-dimensional convolution, and extracting a time mode matrix of the variable in the convolution kernel range; performing maximum pooling and global average pooling to obtain difference feedback and average feedback of the vibration acceleration signals of the convolution kernel, and combining the two feature descriptions; finally, the attention weight coefficient of each signal is obtained by fusing the characteristics of the vibration acceleration signals through the full connection layer;
step 3.2: and constructing a 1DCNN module of the mixed CNN-LSTM model based on an attention mechanism. Firstly, setting a convolution kernel and extracting the spatial characteristics of an acceleration signal; a pooling layer is added behind the convolutional layer, and the parameters with training are reduced while the characteristics irrelevant to the position are obtained;
step 3.3: and constructing an LSTM module of the mixed CNN-LSTM model based on an attention mechanism. Setting a neural network structure in an LSTM module as an LSTM layer, and learning the time characteristics of the acceleration signal;
step 3.4: the attention module, the 1DCNN model and the LSTM module are connected through a Sequential module built in a keras, an output layer is added, and the connected model is a mixed CNN-LSTM model based on the attention system.
In the above scheme, the step 3.1 is specifically as follows:
(1) CNN detection time patterns
Applying a CNN filter to acceleration signal data S, S ∈ RH×WWith H10 and W200, using C convolution kernels Ci∈R1×WPerforming convolution operation on S, performing weighted summation on a convolution kernel and a convolved part, then moving downwards with step length of 1, and performing convolution operation on all signals in sequence, wherein a calculation formula is as follows:
Figure BDA0003391058930000031
convolution operation generates time pattern matrix Fc∈RH×CWherein
Figure BDA0003391058930000032
Representing the convolution value of the ith row vector and the jth filter;
(2) attention weighting
For time pattern matrix FCMaximum pooling (Maxpooling) and global average pooling (averageposing) were performed to obtain differential feedback of 10 acceleration signals per convolution kernel
Figure BDA0003391058930000033
Figure BDA0003391058930000034
And average feedback
Figure BDA0003391058930000035
Wherein
Figure BDA0003391058930000036
Will be provided with
Figure BDA0003391058930000037
And
Figure BDA0003391058930000038
merging, fusing features through a full connection layer, and finally obtaining different acceleration signals through a sigmoid activation functionAttention weight coefficient of number, its calculation process is as follows:
Figure BDA0003391058930000039
in the scheme, the step 4: training a mixed CNN-LSTM model based on an attention mechanism:
step 4.1: dividing a data set;
step 4.2: carrying out hyper-parameter tuning by using a Bayesian optimization method;
and 4.3, inputting a vibration acceleration signal data set, training a neural network, and forming a mixed CNN-LSTM dropper abnormity detection model based on an attention mechanism.
Compared with the prior art, the invention has the following beneficial effects:
the method combines the respective characteristics of the convolutional neural network and the LSTM neural network, extracts the spatial characteristics of a multi-channel signal through one-dimensional convolution, and extracts the time dependence characteristic of the signal through the LSTM.
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FIG. 1 is an overall block diagram of an implementation of the present invention;
FIG. 2 is a schematic diagram of an installation position of an acceleration sensor of a contact network;
FIG. 3 is a block diagram of an attention module;
FIG. 4 is a flow chart of a hybrid CNN-LSTM model training based on an attention mechanism.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
as shown in fig. 1, a hybrid CNN-LSTM dropper breakage detection method based on an attention mechanism specifically includes the following steps:
step 1: acquiring an acceleration signal;
as shown in fig. 2, 5 sensors are mounted on each jumper contact line and catenary:
1# acceleration sensor: 1m inside the supporting point 1 on the carrier cable;
2# acceleration sensor: the inner side of the supporting point 2 on the carrier cable is 1 m;
3# acceleration sensor: the mid-span position of the carrier cable;
4# acceleration sensor: the contact line is arranged at the middle 5 th hanging string;
5# acceleration sensor: the contact line is across the 9 th dropper.
Acquiring horizontal and vertical acceleration signal data of 5 acceleration sensors under 4 working conditions that a first dropper is broken, a midspan dropper is broken, the midspan dropper and the first dropper are broken simultaneously, the first dropper is broken and the midspan dropper is not broken under the action of pulsating wind, and transmitting the acceleration signal data acquired by the sensors to a server end through an NB-IoT network.
Step 2: and (3) building a deep learning environment, and installing a Keras library based on a deep learning framework TensorFlow on a server.
And step 3: constructing a mixed CNN-LSTM model based on an attention mechanism, which comprises the following specific steps:
step 3.1: and constructing an attention module of the mixed CNN-LSTM model based on an attention mechanism. As shown in fig. 3, first, a one-dimensional convolution is performed to extract a time pattern matrix of the variable within the convolution kernel; performing maximum pooling and global average pooling to obtain difference feedback and average feedback of the vibration acceleration signals of the convolution kernel, and combining the two feature descriptions; finally, the attention weight coefficient of each signal is obtained by fusing the characteristics of the vibration acceleration signals through the full connection layer;
the step 3.1 is specifically as follows:
(1) CNN detection time patterns
Applying CNN filters to acceleration signalsData S for input acceleration signal data S ∈ R200×10Turning S' epsilon R in time dimension and characteristic dimension10×200Using C convolution kernels Ci∈R1×200Performing one-dimensional convolution, performing weighted summation on a convolution kernel and a convolved part, then moving downwards by taking the step size as 1, and sequentially performing convolution operation on all signals, wherein the calculation formula is as follows:
Figure BDA0003391058930000051
convolution operation generates time pattern matrix FC∈R10×CWherein
Figure BDA0003391058930000052
Representing the convolution value of the ith row vector and the jth filter;
(2) attention weighting
For time pattern matrix FCMaximum pooling (Maxpooling) and global average pooling (averageposing) were performed to obtain differential feedback of 10 acceleration signals per convolution kernel
Figure BDA0003391058930000061
Figure BDA0003391058930000062
And average feedback
Figure BDA0003391058930000063
Wherein
Figure BDA0003391058930000064
In order to comprehensively extract the characteristics of the signals, the method comprises
Figure BDA0003391058930000065
And
Figure BDA0003391058930000066
merging, fusing features through a full connection layer, and finally passing a sigmoidActivating a function to obtain attention weight coefficients corresponding to 10 acceleration signals, wherein the calculation process is as follows:
Figure BDA0003391058930000067
step 3.2: and constructing a 1DCNN module of the mixed CNN-LSTM model based on an attention mechanism. Firstly, setting a convolution kernel and extracting the spatial characteristics of an acceleration signal; a pooling layer is added behind the convolutional layer, and the parameters with training are reduced while the characteristics irrelevant to the position are obtained;
step 3.3: and constructing an LSTM module of the mixed CNN-LSTM model based on an attention mechanism. Setting a neural network structure in an LSTM module as an LSTM layer, and learning the time characteristics of the acceleration signal;
step 3.4: the attention module, the 1DCNN model and the LSTM module are connected through a Sequential module built in a keras, an output layer is added, and the connected model is a mixed CNN-LSTM model based on the attention system.
And 4, step 4: training a mixed CNN-LSTM model based on an attention mechanism, wherein the model training process is shown in FIG. 4 and comprises the following specific steps:
step 4.1: the data set is partitioned. The sample capacity is 800, and the training set, the verification set and the test set are divided into 512 samples, 128 samples and 160 samples respectively;
step 4.2: and (4) carrying out hyper-parameter tuning by using a Bayesian optimization method. Determining the number of convolution layer units, the size of convolution kernels, the number of LSTM layer units, an activation function and the like by a Bayesian optimization method;
the Bayesian optimization algorithm is a hyper-parametric optimization algorithm. The basic framework is as shown in algorithm 1, and firstly, a probabilistic proxy model f is initialized, which is a fitting to a complex objective function, and common models are: gaussian process, random forest, TPE, etc.; initializing historical observation set D0The observation set consists of a plurality of pairs of data (x, y), wherein x represents a group of hyper-parameters, and y represents target values of the group of hyper-parameters; secondly, searching the next group of hyper-parameter evaluation points x by maximizing the acquisition function alphan+1(ii) a Then the objective function value y of the group of hyper-parameters is calculatedn+1(ii) a Finally will { xn+1,yn+1}Added to the historical observation set DnAnd updating the probability agent model f, and continuously iterating until reaching a defined threshold value.
Figure BDA0003391058930000071
And 4.3, inputting a vibration acceleration signal data set, training a neural network, and forming a mixed CNN-LSTM dropper abnormity detection model based on an attention mechanism.
And 5: acquiring vibration acceleration signal data of a contact network in real time, inputting a trained attention-based hybrid CNN-LSTM dropper abnormity detection model, performing fault diagnosis, and judging whether a dropper is broken, wherein the method comprises the following specific steps:
step 5.1: acquiring vertical and horizontal acceleration signal data of a catenary and a sensor on a contact line;
step 5.2: and inputting the acquired 10 vibration acceleration signal data into a trained attention-based mixed CNN-LSTM model, and judging whether the hanger is broken or not.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (4)

1. A mixed CNN-LSTM dropper anomaly detection method based on an attention mechanism is characterized in that,
the method comprises the following steps:
step 1: acquiring an acceleration signal, and mounting an acceleration sensor on each span of carrier cables and contact lines; acquiring horizontal and vertical acceleration signal data of each acceleration sensor under 4 working conditions that a first dropper is broken, a midspan dropper is broken, the midspan dropper and the first dropper are broken simultaneously, the first dropper is broken and the midspan dropper is not broken under the action of pulsating wind;
step 2: building a deep learning environment, and installing a Keras library based on a deep learning framework TensorFlow on a server;
and step 3: constructing a mixed CNN-LSTM model based on an attention mechanism;
and 4, step 4: training a mixed CNN-LSTM model based on an attention mechanism;
and 5: and acquiring vibration acceleration signal data of the contact network in real time, inputting the trained attention-based hybrid CNN-LSTM dropper abnormity detection model, performing fault diagnosis, and judging whether the dropper is broken.
2. The method of claim 1 for detecting abnormality of mixed CNN-LSTM dropper based on attention mechanism,
and step 3: constructing a mixed CNN-LSTM model based on an attention mechanism:
step 3.1: constructing an attention module of a mixed CNN-LSTM model based on an attention mechanism;
step 3.2: constructing a 1DCNN module of a mixed CNN-LSTM model based on an attention mechanism;
step 3.3: constructing an LSTM module of a mixed CNN-LSTM model based on an attention mechanism;
step 3.4: the attention module, the 1DCNN model and the LSTM module are connected through a Sequential module built in a keras, an output layer is added, and the connected model is a mixed CNN-LSTM model based on the attention system.
3. The method for detecting abnormality of mixed CNN-LSTM dropper based on attention mechanism as claimed in claim 2, wherein the step 3.1 is as follows:
(1) CNN detection time patterns
Applying a CNN filter to acceleration signal data S, S ∈ RH×WWith H10 and W200, using C convolution kernels Ci∈R1×WPerforming convolution operation on S to convolve the convolution kernel with the SThe weighted summation is carried out on the parts, then the weighted summation is moved downwards by the step size of 1, and the convolution operation is carried out on all the signals in turn, and the calculation formula is as follows:
Figure FDA0003391058920000021
convolution operation generates time pattern matrix Fc∈RH×CWherein
Figure FDA0003391058920000022
Representing the convolution value of the ith row vector and the jth filter;
(2) attention weighting
For time pattern matrix FCMaximum pooling (Maxpooling) and global average pooling (averageposing) were performed to obtain differential feedback of 10 acceleration signals per convolution kernel
Figure FDA0003391058920000023
Figure FDA0003391058920000024
And average feedback
Figure FDA0003391058920000025
Wherein
Figure FDA0003391058920000026
Will be provided with
Figure FDA0003391058920000027
And
Figure FDA0003391058920000028
merging, fusing features through a full connection layer, and finally obtaining attention weight coefficients of different acceleration signals through a sigmoid activation function, wherein the calculation process is as follows:
Figure FDA0003391058920000029
4. the method of claim 3 for detecting abnormality of mixed CNN-LSTM dropper based on attention mechanism,
and 4, step 4: training a mixed CNN-LSTM model based on an attention mechanism:
step 4.1: dividing a data set;
step 4.2: carrying out hyper-parameter tuning by using a Bayesian optimization method;
and 4.3, inputting a vibration acceleration signal data set, training a neural network, and forming a mixed CNN-LSTM dropper abnormity detection model based on an attention mechanism.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110672343A (en) * 2019-09-29 2020-01-10 电子科技大学 Rotary machine fault diagnosis method based on multi-attention convolutional neural network
CN111721324A (en) * 2020-05-15 2020-09-29 中铁第一勘察设计院集团有限公司 Contact net dropper breakage detection method based on acceleration signals
CN112200032A (en) * 2020-09-28 2021-01-08 辽宁石油化工大学 Attention mechanism-based high-voltage circuit breaker mechanical state online monitoring method
US20210201010A1 (en) * 2019-12-31 2021-07-01 Wuhan University Pedestrian re-identification method based on spatio-temporal joint model of residual attention mechanism and device thereof
CN113288162A (en) * 2021-06-03 2021-08-24 北京航空航天大学 Short-term electrocardiosignal atrial fibrillation automatic detection system based on self-adaptive attention mechanism

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110672343A (en) * 2019-09-29 2020-01-10 电子科技大学 Rotary machine fault diagnosis method based on multi-attention convolutional neural network
US20210201010A1 (en) * 2019-12-31 2021-07-01 Wuhan University Pedestrian re-identification method based on spatio-temporal joint model of residual attention mechanism and device thereof
CN111721324A (en) * 2020-05-15 2020-09-29 中铁第一勘察设计院集团有限公司 Contact net dropper breakage detection method based on acceleration signals
CN112200032A (en) * 2020-09-28 2021-01-08 辽宁石油化工大学 Attention mechanism-based high-voltage circuit breaker mechanical state online monitoring method
CN113288162A (en) * 2021-06-03 2021-08-24 北京航空航天大学 Short-term electrocardiosignal atrial fibrillation automatic detection system based on self-adaptive attention mechanism

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