Disclosure of Invention
The purpose of the invention is as follows: aiming at the defects of the prior art, the invention aims to provide a method and a system for predictive maintenance based on motor parameters, which judge the health degree of the whole motor based on local motor diagnosis, advance the diagnosis time of the traditional motor fault diagnosis, prevent the motor from generating irreversible damage and reduce the hardware requirement of acquisition equipment.
The technical scheme is as follows: in order to achieve the above object, the present invention provides a method for performing predictive maintenance based on motor parameters, comprising the following steps:
(1) loading a temperature sensor and a vibration sensor at each important part of the motor, wherein each important part at least comprises a bearing and a winding;
(2) numbering temperature sensors and vibration sensors from 1 to n, wherein two types of sensors with the same number are arranged at the same position, and the positions are also numbered by 1 to n; collecting and storing the position i (0) during normal operation<i<n +1) is the data of n +1 types in abnormal working, and each group of data respectively consists of a temperature matrix of n rows and 1 column and a vibration matrix of 1 row and n columns:
and [ V ]
1 V
2 … V
n](ii) a Wherein T is
1~T
nMeasured values, V, output for the temperature sensors 1-n
1~V
nMeasured values output by the
vibration sensors 1 to n;
(4) multiplying the temperature matrix of each group by the vibration matrix to obtain n +1 n-order square matrixes, calculating the eigenvalue and the eigenvector of each group of n-order square matrixes, and taking the vector formed by the eigenvalue of the n-order square matrixes as a standard eigenvalue vector a corresponding to the working state type of the motori;
(5) Comparing the eigenvalue vector b calculated by real-time data acquisition with n +1 standard eigenvalue vectors respectively to obtain delta
i=|b-a
i|,i∈[0,n]N Z and calculating the ratio of the degree of approximation between the actual operating condition and the normal state to the degree of approximation between the normal state and the abnormal state
And the ratio logarithm transformation and the trigonometric function transformation are used for obtaining the local health degree r
i;
(6) Calculating comprehensive health degree by local health degree
When the real-time comprehensive health degree is continuously reduced or less thanIf the set threshold value is not in a healthy state, the motor is judged to be in an unhealthy state, and the local health degree r is positioned
iPositions that are continuously reduced or less than a set threshold are abnormal positions, and predictive maintenance is achieved.
Preferably, the step (2) acquires temperature and vibration data of normal and abnormal operations at different dates or air temperatures, respectively, and the step (5) selects and compares the standard characteristic value corresponding to the current date or air temperature.
Preferably, the degree of local health
Preferably, the method further comprises the step of marking the ratio of the closeness degree of the actual working condition to the normal state to the closeness degree of the abnormal state on the n-polygon graph to obtain an n-polygon working condition comparison graph, and visually showing the trend of the current working state of the motor.
Preferably, in the step (2), abnormal operation parameters are acquired through replacement of motor parts or noise signals are constructed and added to the normal operation parameters to simulate the abnormal operation parameters.
The invention discloses a system for performing predictive maintenance based on motor parameters, which comprises:
each working condition standard characteristic acquisition module is used for numbering a temperature sensor and a vibration sensor from 1 to n, two types of sensors with the same number are arranged at the same position of a motor, the arranged positions at least comprise a bearing and a winding, and the positions are also numbered by 1 to n; collecting and storing the position i (0) during normal operation<i<n +1) is the data of n +1 types in abnormal working, and each group of data respectively consists of a temperature matrix of n rows and 1 column and a vibration matrix of 1 row and n columns:
and [ V ]
1 V
2 … V
n](ii) a Wherein T is
1~T
nMeasured values, V, output for the temperature sensors 1-n
1~V
nMeasured values output by the
vibration sensors 1 to n;
and multiplying the temperature matrix of each group by the vibration matrix to obtain n +1 n-order square matrixes, calculating the eigenvalue and the eigenvector of each group of n-order square matrixes, and taking the vector formed by the eigenvalue of the n-order square matrix as the standard eigenvalue vector a corresponding to the working state type of the motori;
A real-time local health degree calculation module for comparing the eigenvalue vector b calculated by the real-time collected data with the n +1 standard eigenvalue vectors to calculate delta
i=|b-a
i|,i∈[0,n]N Z and calculating the ratio of the degree of approximation between the actual operating condition and the normal state to the degree of approximation between the normal state and the abnormal state
And the ratio logarithm transformation and the trigonometric function transformation are used for obtaining the local health degree r
i;
And an abnormal prediction module for calculating the comprehensive health degree according to the local health degree
When the real-time comprehensive health degree is continuously reduced or is smaller than a set threshold value, the motor is judged to be in an unhealthy state, and the local health degree r is positioned
iPositions that are continuously reduced or less than a set threshold are abnormal positions, and predictive maintenance is achieved.
Preferably, the system further comprises a working condition comparison diagram drawing module, wherein the working condition comparison diagram drawing module is used for marking the ratio of the degree of approach of the actual working condition to the normal state to the degree of approach of the abnormal state on the n-edge diagram to obtain the n-edge working condition comparison diagram, and visually showing the trend of the current working state of the motor.
Has the advantages that: compared with the prior art, the invention has the following advantages:
1. the invention collects the temperature and vibration parameters of the motor to carry out cross calculation, can more accurately obtain the abnormal working state of the motor, and can avoid collecting electrical parameters, such as current and voltage, which need to be provided with related transmitters during collection and are difficult to be provided on a finished motor;
2. the invention directly collects direct variable quantities such as temperature, vibration and the like, and also includes environmental change factors such as seasons and the like on the basis of statistical calculation, and edge collection equipment can judge weather and air temperature by obtaining a time stamp of local time through month, day and time parameters or directly obtains the air temperature of the day through networking, and distinguishes characteristic values of various seasons and various weathers after statistics and calculation, so that the robustness of the predictive maintenance system is greatly improved;
3. the algorithm calculation is carried out by adopting two streams of real-time calculation and statistical calculation, and the statistical calculation stream is independent of the real-time calculation stream, so that the calculation cost of the edge acquisition equipment is reduced, and the hardware cost is reduced;
4. the invention positions the predictive maintenance to the local part of the motor, is different from the traditional integral fault diagnosis method, improves the robustness of the predictive maintenance method and reduces the manual detection cost;
5. the method has good adaptability in predicting the change of the motor object;
6. the invention can generate an n-edge working condition comparison graph, so that people can intuitively know the health state of each part of the motor.
Detailed Description
The present invention is further illustrated by the following examples, which are intended to be purely exemplary and are not intended to limit the scope of the invention, as various equivalent modifications of the invention will occur to those skilled in the art upon reading the present disclosure and fall within the scope of the appended claims.
As shown in fig. 1, a method for performing predictive maintenance based on motor parameters disclosed in the embodiment of the present invention mainly includes the following steps:
(1) the method comprises the following steps that temperature sensors and vibration sensors are loaded at important parts of a motor to receive data, key collection points of the motor are bearings and windings, and n temperature sensors and n vibration sensors can be respectively arranged at the parts;
(2) the temperature sensor and the vibration sensor can be numbered from 1 to n, two types of sensors with the same number are arranged at the same position, and the positions are also numbered from 1 to n;
(3) collecting data in a period of time and storing the data; the data acquisition is divided into two parts, the first layer is a sensor part, temperature signals and vibration signals can be converted into signal types which can be received by acquisition equipment, such as 4-20mA direct current standard industrial signals, 0-5V voltage signals and the like, data are transmitted to edge acquisition equipment for calculation through a series of protocols, such as an i2c protocol, a single bus protocol and the like, and calculation results are transmitted to a cloud server through the Internet.
(4) N +1 types of data are counted and grouped, namely, when the temperature T and the vibration V are in a normal range and the position i (0)<i<n +1) abnormal operation (temperature TiOr ViValues outside the normal range), each set of data consisting of n rows and 1 column of temperature matrix and 1 row and n columns of vibration matrix respectively:
The values of the two matrices should be taken at the same time. The parameters of the abnormal working scene can be constructed in two modes, the first mode can replace the intact motor parts with damaged motor parts, carry out operation experiments and collect operation parameters, and the scheme has high cost and high data reliability; the second method can use MATLAB to construct noise signal and add it to the operating parameter of normal operation to simulate abnormal operating parameter, and this scheme has lower cost but slightly lower data reliability. The parameters of normal and abnormal working scenes under different dates can be obtained through MATLAB simulation, because the weather of the same place on the same date should be the same or similar, the temperature of each day in the year can be subjected to grouping processing through the MATLAB, the temperature matrix can be corrected according to the temperature array of each day, if the temperature corresponding to the temperature array of the day is increased or decreased by x ℃ compared with that of the previous day, each element of the temperature matrix of the day should also be increased or decreased by x ℃, and the timestamp of the day can be obtained from the Internet.
(5) Multiplying the temperature matrix of each group by the vibration matrix to obtain n +1 n-order square matrixes:
the n-order square matrix represents the correlation between the temperature and the vibration of all n parts at the same time, wherein the main symmetry axis is the correlation between the temperature and the vibration of the same part;
(6) calculating the eigenvalue and eigenvector of each group of n-order square matrix, calculating n eigenvalues and eigenvectors in the complex domain, wherein the vector formed by the n eigenvalues can be expressed as the standard eigenvalue vector a of the current motor working state type (part i is abnormally working or all parts are normally working, and i is 0 during normal working)i=[λ1 λ2 … λn]If the motor works in the same or similar state, the calculated characteristic value vector is the same as or similar to the standard characteristic value vector of the working state type (through threshold value comparison);
(7) comparing the eigenvalue vector b obtained by calculating the actual collected data at the time t with the n +1 standard eigenvalue vectors respectively to obtain deltai=|b-ai|,i∈[0,n]∩Z,ΔiIs a quantity, Δ, representing the proximity of the current operating state to the point i in an abnormal operating stateiThe smaller the value of (b), the more the current working state tends to the abnormal state of the part i;
(8) calculated value
By calculating the ratio of the proximity of the actual operating conditions to the normal state to the proximity of the abnormal state, a value σ in the range of (0, + ∞) can be obtained and labeled on the n-gon, as shown in fig. 2. The polygon axes can be displayed by adjusting the type of the axes according to the size of sigma on each axis, and when the sigma difference is large, the polygon axes can be represented by logarithmic axes, and when the difference is small, the polygon axes can be represented by linear axes.
(9) The trend of the current working state of the motor can be intuitively seen from the n-edge diagram, the motor can be in one or more abnormal working states, and the specific abnormal working state part of the motor can be positioned by a program.
(10) Since the included angle between vectors may be close to 180 °, the modulus may be quite large, so performing logarithmic transformation and trigonometric transformation on the calculated σ may result in a local health score:
(11) the comprehensive health degree can be calculated through the local health degree:
(12) and calculating a derivative of the real-time comprehensive health degree, judging that the motor is in an unhealthy state when R' is continuously in a state less than zero for a long time or the R value is too low, and positioning, maintaining and repairing according to a program. If the local health degree riIf the value is judged to be continuously decreased or too low in the program, the part i is considered to be abnormal.
The invention discloses a system for performing predictive maintenance based on motor parameters, which comprises: each working condition standard characteristic acquisition module is used for acquiring and storing n +1 types of data in normal working and abnormal working at the position i, multiplying the temperature matrix of each group by the vibration matrix to obtain n +1 n-order square matrixes, calculating the characteristic value and the characteristic vector of each group of n-order square matrixes, and taking the vector formed by the characteristic values of the n-order square matrixes as the corresponding electric powerStandard eigenvalue vector a of the machine operating state typei(ii) a The real-time local health degree calculation module is used for comparing the characteristic value vector b calculated by the real-time collected data with the n +1 standard characteristic value vectors respectively and calculating the ratio of the approach degree of the actual working condition and the normal state to the approach degree of the abnormal state so as to obtain the local health degree ri(ii) a The working condition comparison diagram drawing module is used for drawing an n-polygon working condition comparison diagram according to the ratio of the approximation degree of the actual working condition and the normal state to the approximation degree of the abnormal state, and visually showing the trend of the current working state of the motor; and the abnormal prediction module is used for calculating the comprehensive health degree through the local health degree, judging whether the motor is in an abnormal state according to the comprehensive health degree and realizing predictive maintenance. The specific implementation details are referred to the above method embodiments, and are not described herein again.
The invention completes the work of motor parameter statistics and algorithm analysis in advance without real-time calculation, thereby reducing the workload of acquisition equipment and avoiding unnecessary hardware cost; the method generates the health degree of the motor in real time, forms a mapping relation between the health degree of the motor and an intuitive hardware acquisition parameter (non-electrical parameter), can be influenced from two aspects of vibration and temperature, and judges the health degree of the motor, wherein the health degree of the motor is a continuously variable quantity in a time domain, and the predictive maintenance can be realized by judging the variation trend of the health degree in a period of time, so that the diagnosis time of the traditional motor fault diagnosis is advanced, the irreversible damage of the motor can be well prevented, and the fault tolerance of the motor is facilitated; the invention starts from the local part of the motor, and carries out cross calculation through two non-electric acquisition parameters without direct connection, thereby improving the accuracy of the algorithm, still judging the health degree of the whole motor through local diagnosis and detection when one motor is changed, and increasing the robustness of the system.