Large hydraulic machine fault diagnosis method and device based on HSMM-SVM model
阅读说明：本技术 基于hsmm-svm模型的大型液压机故障诊断方法与装置 (Large hydraulic machine fault diagnosis method and device based on HSMM-SVM model ) 是由 何彦虎 于 2019-09-17 设计创作，主要内容包括：本发明提供基于HSMM-SVM模型的大型液压机故障诊断方法与装置,属于液压机故障诊断技术领域。该基于HSMM-SVM模型的大型液压机故障诊断方法与装置包括如下步骤：S1：采集液压机的诊断信号；S2：通过对诊断信号进行处理以提取特征向量；S3：建立HSMM-SVM模型的分类器,将特征向量输入分类器中得到故障信息。本发明首先采集液压机的诊断信号,然后通过对诊断信号进行处理以提取特征向量,接着建立HSMM-SVM模型的分类器,将特征向量输入分类器中得到故障信息,这样可以获取液压机上的故障的诊断信息,精度较高,效率较高。(The invention provides a fault diagnosis method and device for a large hydraulic machine based on an HSMM-SVM model, and belongs to the technical field of fault diagnosis of hydraulic machines. The method and the device for diagnosing the fault of the large hydraulic machine based on the HSMM-SVM model comprise the following steps: s1: collecting a diagnosis signal of the hydraulic machine; s2: extracting a feature vector by processing the diagnostic signal; s3: and establishing a classifier of the HSMM-SVM model, and inputting the feature vector into the classifier to obtain fault information. The method comprises the steps of firstly collecting diagnosis signals of the hydraulic machine, then processing the diagnosis signals to extract the feature vectors, then establishing a classifier of the HSMM-SVM model, and inputting the feature vectors into the classifier to obtain fault information, so that the diagnosis information of the faults on the hydraulic machine can be obtained, and the method is high in precision and efficiency.)
1. The fault diagnosis method of the large hydraulic machine based on the HSMM-SVM model is characterized by comprising the following steps of:
s1: collecting a diagnosis signal of the hydraulic machine;
s2: extracting a feature vector by processing the diagnostic signal;
s3: and establishing a classifier of the HSMM-SVM model, and inputting the feature vector into the classifier to obtain fault information.
2. The fault diagnosis method for the large hydraulic machine based on the HSMM-SVM model as claimed in claim 1, wherein: the diagnosis signals comprise a hydraulic pressure signal, a hydraulic flow signal, a hydraulic temperature signal, a power failure condition of an electromagnetic valve and a vibration signal of the hydraulic machine.
3. The fault diagnosis method for large hydraulic machine based on HSMM-SVM model according to claim 1 or 2, characterized in that: in step S3, the classifier is trained by inputting the feature vectors into the classifier, and the classification precision of the classifier is verified so that the accuracy of the classifier reaches a preset precision.
4. The fault diagnosis method for the large hydraulic machine based on the HSMM-SVM model as claimed in claim 3, wherein: in step S2, removing noise from the diagnostic signal by wavelet threshold to obtain a filtered signal, decomposing the filtered signal by empirical mode EMD to obtain intrinsic mode function IMF, and calculating the intrinsic mode function IMF according to the formula
5. The fault diagnosis method for the large hydraulic machine based on the HSMM-SVM model as claimed in claim 2, wherein: the hydraulic pressure signal is collected through a PPM-T322H pressure sensor, the hydraulic flow signal is collected through an FT-330 type sensor, and the vibration signal is collected through an SG2000 vibration sensor.
6. The fault diagnosis method for large hydraulic machine based on HSMM-SVM model according to claim 1 or 2, characterized in that: the HSMM and the SVM are fused in series, in parallel or embedded to form an HSMM-SVM model.
7. The fault diagnosis method for the large hydraulic machine based on the HSMM-SVM model as claimed in claim 5, wherein: the classifier includes a fault model library for storing preset fault classifications.
8. Large-scale hydraulic press fault diagnosis device based on HSMM-SVM model, its characterized in that: the hydraulic pressure and flow rate diagnosis system comprises a signal acquisition unit for acquiring diagnosis signals of the hydraulic machine, a signal processing unit for receiving and processing the diagnosis signals into eigenvectors and a classifier for analyzing the eigenvectors to obtain fault information, wherein the diagnosis signals comprise hydraulic pressure signals, hydraulic flow rate signals, hydraulic temperature signals, power failure conditions of an electromagnetic valve and vibration signals of the hydraulic machine.
9. The fault diagnosis device for the large-scale hydraulic machine based on the HSMM-SVM model as claimed in claim 8, wherein: the hydraulic pressure signal is collected through a PPM-T322H pressure sensor, the hydraulic flow signal is collected through an FT-330 type sensor, and the vibration signal is collected through an SG2000 vibration sensor.
10. The fault diagnosis device for the large hydraulic machine based on the HSMM-SVM model according to claim 8 or 9, wherein: the signal processing unit comprises a filtering module, an IMF (empirical mode decomposition) module, an energy moment module and a feature vector construction module, wherein the filtering module is used for removing noise of a diagnostic signal through a wavelet threshold value to obtain a filtering signal, the IMF module is used for obtaining an intrinsic mode function IMF (intrinsic mode function) through an EMD (empirical mode decomposition) filtering signal, the energy moment module is used for calculating an energy moment of the intrinsic mode function IMF, and the feature vector construction module is used for constructing a feature vector for the energy moment and normalizing the feature vector.
Technical Field
The invention belongs to the technical field of hydraulic machine fault diagnosis, and relates to a fault diagnosis method and device for a large hydraulic machine based on an HSMM-SVM model.
Background
The hydraulic technology becomes one of key technologies in the industrial fields of all countries in the world, according to incomplete statistics, more than 95% of mechanical equipment adopts the hydraulic technology and devices, the hydraulic machine is a core device which must be adopted for processing and forging various high-strength steel, carbon steel and alloy steel, is widely used in equipment in the heavy industrial fields of aerospace, steel, large-scale bearing parts, nuclear industry, military, ships, cranes, artificial boards and the like, is key equipment in national economic strut industries of energy, petroleum, metallurgy and the like, and some hydraulic machines are strategic equipment required by industrial systems and national defense, are basic equipment for developing large military equipment and large industrial equipment in China, mark the national comprehensive production capacity and technical development level, and are of great importance in reliability and safe operation. The hydraulic machine is essentially a system integrating electro-hydraulic control, and has complex control and difficult fault diagnosis. The fault shutdown not only reduces the production efficiency of enterprises and causes huge economic loss, but also brings great difficulty to the production enterprises because the maintenance technology of the hydraulic equipment is locked abroad, thereby having great practical significance for the reliable operation, fault diagnosis and health prediction of the hydraulic equipment.
Disclosure of Invention
The invention provides a fault diagnosis method and a fault diagnosis device for a large hydraulic machine based on an HSMM-SVM model aiming at the problems in the prior art, and the technical problems to be solved by the invention are as follows: how to provide a fault diagnosis method and a fault diagnosis device for a large hydraulic machine based on an HSMM-SVM model.
The purpose of the invention can be realized by the following technical scheme:
the fault diagnosis method of the large hydraulic machine based on the HSMM-SVM model comprises the following steps:
s1: collecting a diagnosis signal of the hydraulic machine;
s2: extracting a feature vector by processing the diagnostic signal;
s3: and establishing a classifier of the HSMM-SVM model, and inputting the feature vector into the classifier to obtain fault information.
Preferably, the diagnosis signal comprises a hydraulic pressure signal, a hydraulic flow signal, a hydraulic temperature signal, a power failure condition of an electromagnetic valve and a vibration signal of the hydraulic machine.
Preferably, the classifier is trained by inputting the feature vectors into the classifier in step S3, and the classification precision of the classifier is verified so that the accuracy of the classifier reaches the preset precision.
Preferably, in step S2, noise is removed from the diagnostic signal by a wavelet threshold to obtain a filtered signal, the filtered signal is decomposed by an empirical mode EMD to obtain an intrinsic mode function IMF, an energy moment of each intrinsic mode function IMF is obtained according to a formula, and the energy moment is constructed into a feature vector and normalized according to the formula.
Preferably, the hydraulic pressure signal is acquired by a PPM-T322H pressure sensor, the hydraulic flow signal is acquired by an FT-330 type sensor, and the vibration signal is acquired by an SG2000 vibration sensor.
Preferably, the HSMM and SVM are fused in series, in parallel or embedded to form an HSMM-SVM model.
Preferably, the classifier includes a fault model library for storing preset fault classifications.
The fault diagnosis device for the large hydraulic machine based on the HSMM-SVM model comprises a signal acquisition unit, a signal processing unit and a classifier, wherein the signal acquisition unit is used for acquiring diagnosis signals of the hydraulic machine, the signal processing unit is used for receiving and processing the diagnosis signals into eigenvectors, the classifier is used for analyzing the eigenvectors to obtain fault information, and the diagnosis signals comprise hydraulic pressure signals, hydraulic flow signals, hydraulic temperature signals, power failure conditions of an electromagnetic valve and vibration signals of the hydraulic machine.
Preferably, the hydraulic pressure signal is acquired by a PPM-T322H pressure sensor, the hydraulic flow signal is acquired by an FT-330 type sensor, and the vibration signal is acquired by an SG2000 vibration sensor.
Preferably, the signal processing unit includes a filtering module for removing noise from the diagnostic signal by a wavelet threshold to obtain a filtered signal, an IMF mode module for obtaining an intrinsic mode function IMF of the intrinsic mode function by decomposing the filtered signal by an empirical mode EMD, an energy moment module for calculating an energy moment of the intrinsic mode function IMF, and a feature vector construction module for constructing and normalizing feature vectors for the energy moment.
According to the method, the diagnostic signal of the hydraulic machine is collected firstly, then the diagnostic signal is processed to extract the characteristic vector, then the classifier of the HSMM-SVM model is built, and the characteristic vector is input into the classifier to obtain the fault information, so that the diagnostic information of the fault on the hydraulic machine can be obtained, and the method is high in precision and efficiency.
Drawings
FIG. 1 is a schematic flow diagram of the present invention.
Detailed Description
The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.
Referring to fig. 1, the method for diagnosing a fault of a large hydraulic machine based on an HSMM-SVM model in the present embodiment includes the following steps:
s1: collecting a diagnosis signal of the hydraulic machine;
s2: extracting a feature vector by processing the diagnostic signal;
s3: and establishing a classifier of the HSMM-SVM model, and inputting the feature vector into the classifier to obtain fault information.
The diagnosis signals comprise a hydraulic pressure signal, a hydraulic flow signal, a hydraulic temperature signal, a power failure condition of the electromagnetic valve and a vibration signal of the hydraulic machine.
In step S3, the classifier is trained by inputting the feature vectors into the classifier, and the classification precision of the classifier is verified so that the accuracy of the classifier reaches a preset precision.
In a laboratory environment, firstly, a hydraulic working circuit is built, pressure flow data of each measuring point are collected, after filtering, a feature vector is extracted, then a built HSMM-SVM model is trained, classification precision is verified, and when the accuracy does not meet the requirement, an HSMM-SVM model algorithm is modified until the requirement is met. Under the field condition, the collected data needs to be processed under the influence of the environment, particularly the influence of electromagnetic interference and temperature, for example, an intelligent denoising algorithm can successfully remove noise caused by the environment according to the change of the environment and search a characteristic value. And then, carrying out dynamic test, namely observing and extracting the change rule of the characteristic value when the equipment works, classifying by adopting the classifier used in the step one, observing the precision, and adjusting the model algorithm until the requirement is met.
In step S2, noise is removed from the diagnostic signal by wavelet threshold to obtain a filtered signal, the filtered signal is decomposed by empirical mode EMD to obtain intrinsic mode functions IMF, energy moments of the intrinsic mode functions IMF are obtained according to a formula, and the energy moments are constructed into eigenvectors and normalized according to the formula.
The hydraulic pressure signal is collected by a PPM-T322H pressure sensor, the hydraulic flow signal is collected by an FT-330 type sensor, and the vibration signal is collected by an SG2000 vibration sensor.
The HSMM and the SVM are fused in series, in parallel or embedded to form an HSMM-SVM model.
The classifier includes a fault model library for storing preset fault classifications.
The large hydraulic machine fault diagnosis device based on the HSMM-SVM model comprises a signal acquisition unit, a signal processing unit and a classifier, wherein the signal acquisition unit is used for acquiring diagnosis signals of a hydraulic machine, the signal processing unit is used for receiving and processing the diagnosis signals into eigenvectors, the classifier is used for analyzing the eigenvectors to obtain fault information, and the diagnosis signals comprise hydraulic pressure signals, hydraulic flow signals, hydraulic temperature signals, power failure conditions of an electromagnetic valve and vibration signals of the hydraulic machine.
The hydraulic pressure signal is collected by a PPM-T322H pressure sensor, the hydraulic flow signal is collected by an FT-330 type sensor, and the vibration signal is collected by an SG2000 vibration sensor.
The signal processing unit comprises a filtering module, an IMF (empirical mode decomposition) module, an energy moment module and a feature vector construction module, wherein the filtering module is used for removing noise of a diagnostic signal through a wavelet threshold value to obtain a filtering signal, the IMF module is used for obtaining an intrinsic mode function IMF (intrinsic mode function) through an EMD (empirical mode decomposition) filtering signal, the energy moment module is used for calculating an energy moment of the intrinsic mode function IMF, and the feature vector construction module is used for constructing a feature vector for the energy moment and normalizing the feature vector.
HSMM is represented by λ = (N, M, pi, a, B, p (j, d)). Each HSMM still includes a sequence of states and a sequence of observations, at time t, the observations of each HSMM are related only to the state at that time, the state being related to the state of its own t-1. Because of the need to find a set of observations
The state transition reestimation formula of the HSMM model isWherein
The SVM adopts the idea of minimizing the structural risk, can convert nonlinearity into a high-dimensional feature space, and realizes the nonlinear classification of a low-dimensional space by using a linear discriminant function in the high-dimensional space, so that the linear regression in the high-dimensional feature space corresponds to the nonlinear regression of the low-dimensional space, the SVM can always find an optimal classification hyperplane, and the blank areas on two sides of the hyperplane are maximized to realize the optimal classification.
Considering the training sample set { (xi, di) i =1, 2, 3, ….. l }, xi being the ith input and di being the desired output, for a given weight vector w and a bias b, the optimal hyperplane discriminant function is the expression wT + b =0, where w is the adjustable weight vector and b is the bias. By using training samples
The value of the SVM parameter influences the learning ability and generalization ability of the SVM, so that the determination of the parameter value is an important research content of the SVM. For an SVM with RBF kernel function, the parameters include the tuning parameter C, the kernel width σ, and the insensitive number e. The SVM parameters are adjusted, so that the SVM-based learning method has very strong learning ability and generalization ability. The HSMM and SVM can be fused in series, parallel or embedded to form the HSMM-SVM analysis system. In the series hybrid mode, the HSMM calculates the likelihood of each state, then sorts all the likelihoods, takes the values of the first N likelihoods (other likelihoods are obviously distinguishable), classifies the N likelihoods by the SVM, if the class number corresponding to the maximum likelihood of the HSMM is consistent with the classification result of the SVM, the conclusion can be considered to be correct, otherwise, the classification result is determined to be more reasonable according to the discrimination function. For the parallel mode, the HSMM and the SVM operate oppositely, and the likelihood voting function is used for voting the classified results to determine which result is more reasonable. The most complicated is the embedded algorithm of the HSMM and the SVM, the SVM needs to be embedded into the HSMM, then forward and backward, model parameter estimation and the like are adopted for demonstration, and finally the effect is programmed and debugged.
The working process of the press comprises 10 working states of descending, pressurizing, pressure maintaining, pressure releasing, lifting and the like of the press. Each working state corresponds to the power on and power off of different electromagnetic valves respectively, and simultaneously corresponds to the change of pressure and flow at different points of the system. When the hydraulic press works, 10 hydraulic presses are normalThe hydraulic press runs in a reciprocating mode, when a certain element has a problem, the hydraulic press enters a fault state, common faults of the hydraulic press mainly include abnormal sliding, no lifting, no pressurization, no pressure maintaining, poor pressure maintaining and the like of the hydraulic press, and the fault reasons mainly include seal damage, valve blockage, burning out of an electromagnetic coil and the like. In the fault diagnosis, an HSMM-SVM needs to be trained for each state, 10 normal states need to be trained, meanwhile, fault states need to be trained, fault data are difficult to obtain, data do not exist in all faults, a 'likelihood model library' is adopted in a project, namely, a fault model which can possibly occur is constructed, then principle analysis data, historical fault data or similar equipment are used for obtaining training data, the training data are used for training the model, when the faults occur, a self-learning method is adopted in the system, the 'likelihood model' is corrected by actually obtained data, and the fault model library is gradually improved. The trained model can be used for fault diagnosis. For any test data O, likelihood probabilities of different states are calculated respectively
And if lambda is a model for training the HSMM in a normal state, the data O to be measured obtains a probability P (O | lambda) on the model, and the deviation degree is measured by using the probability. To prevent data overflow, data compression is performed on the data, and likelihood probabilities LL, LL = log P (O | λ) can be obtained. Order to
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.