The content of the invention
Technical problem underlying to be solved by this invention is:How one is set up using the modeling approach for lacking variable more may be used
The nongausian process monitoring model leaned on.Therefore, the invention provides a kind of nongausian process based on missing variable modeling thinking
Monitoring method.This method is on the basis of traditional IC A models, by being estimated after assuming each measurand missing data one by one
Corresponding independent element.Then, with the error between independent element actual value and estimate as monitored target, set up appropriate
Statistic implements online process monitoring.
The present invention solve the technical scheme that is used of above-mentioned technical problem for:It is a kind of based on missing variable modeling thinking it is non-
Gaussian process monitoring method, comprises the following steps:
(1) sample data under production process normal operating condition is collected using sampling system, constitutes training data matrix:
X∈Rn×m, and X is standardized, the average for making each measurand is 0, and variance is 1, obtains new data matrixWherein, n is number of training, and m is process measurement variable number, and R is set of real numbers, Rn×mRepresent n × m
The real number matrix of dimension,For matrixIn k-th of variable n measurement data, k=1,2 ..., m.
(2) it is using ICA algorithmICA models are set up, i.e.,:Wherein,For d solely
Vertical composition Column vector groups into matrix, W ∈ Rm×dFor separation matrix, A ∈ Rm×dFor hybrid matrix, E ∈ Rn×mRepresent model error,
The transposition of upper label T representing matrixs or vector.
(3) matrix is assumedMiddle kth column data missing, remaining available column composition matrix Xk∈Rn×(m-1), and utilize following institute
Show that formula calculates the estimate for obtaining independent element matrix
In above formula, Ak∈R(m-1)×dTo remove the matrix obtained by row k in hybrid matrix A.
(4) actual value S and estimate are calculatedBetween errorAnd calculating matrix FkCovariance matrix
Ck=Fk TFk/(n-1)。
(5) calculating matrix CkCharacteristic vector α corresponding to eigenvalue of maximumk∈Rd×1, juxtaposition
(6) k < m are judgedIf so, then putting return to step after k=k+1 (3);If it is not, then performing step (7).
(7) calling model parameter setImplement online process monitoring, specific implementation process
It is as follows:
1. the sampled data y at production process object newest moment is gatherednew∈R1×m, it is carried out and X same standards
Processing is obtained
2. sample vector is calculatedThe actual value of corresponding independent element vectorAnd initialize k=1.
3. sample vector is assumedIn k-th variable data missing, willThe middle new vector of remainder data composition
And utilize formulaCalculate the estimate for obtaining independent element vector
4. the error between the actual value and estimate of independent element vector is calculated
5. monitoring and statisticses amount Q is calculated according to formula as followsk:
Qk=(fkαk)2 (1)
7. k < m are judgedIf so, then putting after k=k+1 return to step 3.;If it is not, then performing step 8..
8. Q=max { Q are put1, Q2..., QmAfter, judge whether to meet condition:If so, then current sample is just
Normal sample, 1. production process is in normal operating conditions and returned continues to monitor next new samples;If it is not, then the sample is event
Hinder sample, production process enters damage and triggers fault warning.Wherein, symbol max { } represents to take maximum,Table
It is that 1, confidence level is numerical value corresponding to δ chi square distribution to show the free degree.
Compared with conventional method, the advantage of the inventive method is mainly reflected in following two aspects:
On the one hand, the object of the inventive method monitoring is the evaluated error of independent element, although independent element is non-gaussian
Distribution but error general Gaussian distributed in itself.It can be said that the inventive method is will by lacking the modeling approach of variable
Nongausian process sampled data is cleverly converted to the error information of Gaussian Profile, and the control that should determine that is limited also with regard to that can align
Regular data carries out more accurate description.On the other hand, the inventive method is by assuming each measurand shortage of data one by one, from
And establish the Fault Model equal with monitored parameterses number.With fault detection method of the tradition based on single ICA models
Compare, the inventive method has also played the strong advantage of multi-model generalization ability.In summary two aspect advantage, the inventive method is
A kind of nongausian process monitoring method being more highly preferred to.
Embodiment
The inventive method is described in detail below in conjunction with the accompanying drawings.
As shown in figure 1, the present invention relates to a kind of nongausian process monitoring method based on missing variable modeling thinking, the party
The specific implementation step of method is as follows:
(1) sample data under production process normal operating condition is collected using sampling system, constitutes training data matrix:
X∈Rn×m, and X is standardized, the average for making each measurand is 0, and variance is 1, obtains new data matrixWherein, n is number of training, and m is process measurement variable number, and R is set of real numbers, Rn×mRepresent n × m
The real number matrix of dimension,For matrixIn k-th of variable n measurement data, k=1,2 ..., m.
(2) it is using ICA algorithmICA models are set up, and initialize k=1.Set up the implementation process of ICA models such as
Shown in lower:
1. calculateCovariance matrixWherein C ∈ Rm×m;
2. calculating matrix C all characteristic values and characteristic vector, and reject characteristic value less than 0.0001 and its corresponding
Characteristic vector, obtains eigenvectors matrix P=[p1, p2..., pM]∈Rm×MAnd characteristic value diagonal matrix D=diag (λ1,
λ2..., λM)∈RM×M;
It is worth noting that, solving obtained characteristic vector p here1, p2..., pMIt all must be the vector of unit length.
3. according to formulaIt is rightWhitening processing is carried out, Z ∈ R are obtainedn×M, and initialize i=1;
4. column vector c is takeniThe i-th row in unit matrix are tieed up for M × M,
5. c is updated according to formula as followsi, i.e.,:
ci←E{Zg(ci TZ)}-E{h(ci TZ)}ci (2)
In above formula (2), E { } represents to ask for desired value (i.e. vectorial average value), function g and the h following institute of concrete form
Show:
G (u)=tanh (u) (3)
H (u)=[sech (u)]2 (4)
In above formula (3) and (4), u is function argument, refers herein to ci TElement in Z.
6. to the vectorial c after renewaliCarry out orthogonal standardization according to the following formula successively:
ci←ci/||ci|| (6)
7. repeat step 5.~6. until vector ciConvergence, and preserve vectorial ci;
8. i < M are judgedIf so, put after i=i+1, repeat step 4.~8.;If it is not, performing step 9.;
9. by obtained all M vector c1, c2..., cMConstitute Matrix C=[c1, c2..., cM]∈RM×M, and according to such as
Formula calculates separation matrix W shown in lower0∈Rm×MWith hybrid matrix A0∈Rm×M:
A0=PD1/2C (7)
W0=PD-1/2C (8)
10. A is calculated0In each column vector length, L is designated as respectively1, L2..., LM, and by L1, L2..., LMAccording to numerical value
Size carries out descending arrangement and obtains l1, l2..., lM, then the independent element number d of reservation is the minimum value for meeting following condition:
By A0The hybrid matrix A ∈ R of d maximum Column vector groups Cheng Xin of middle column vector lengthm×d, while from W0In take
Go out Column vector groups corresponding with A into new separation matrix W ∈ Rm×d;
The ICA models finally obtained areWherein,For d independent element arrange to
Measure the matrix of composition, E ∈ Rn×mRepresent model error.
(3) matrix is assumedMiddle kth column data missing, remaining available column composition matrix Xk∈Rn×(m-1), and utilize following institute
Show that formula calculates the estimate for obtaining independent element matrix
In above formula, Ak∈R(m-1)×dTo remove the matrix obtained by row k in hybrid matrix A.
(4) actual value S and estimate are calculatedBetween errorAnd calculating matrix FkCovariance matrix
Ck=Fk TFk/(n-1)。
(5) calculating matrix CkCharacteristic vector α corresponding to eigenvalue of maximumk∈Rd×1, juxtaposition
(6) k < m are judgedIf so, then putting return to step after k=k+1 (3);If it is not, then performing step (7).
(7) calling model parameter setImplement online process monitoring, specific implementation process
It is as follows:
1. the sampled data y at production process object newest moment is gatherednew∈R1×m, it is carried out and X same standards
Processing is obtained
2. sample vector is calculatedThe actual value of corresponding independent element vectorAnd initialize k=1.
3. sample vector is assumedIn k-th variable data missing, willThe middle new vector of remainder data composition
And utilize formulaCalculate the estimate for obtaining independent element vector
4. the error between the actual value and estimate of independent element vector is calculated
5. monitoring and statisticses amount Q is calculated according to formula as followsk:
Qk=(fkαk)2 (11)
7. k < m are judgedIf so, then putting after k=k+1 return to step 3.;If it is not, then performing step 8..
8. Q=max { Q are put1, Q2..., QmAfter, judge whether to meet condition:If so, then current sample is just
Normal sample, 1. production process is in normal operating conditions and returned continues to monitor next new samples;If it is not, then the sample is event
Hinder sample, production process enters damage and triggers fault warning.Wherein, symbol max { } represents to take maximum,Table
It is that 1, confidence level is numerical value corresponding to δ chi square distribution to show the free degree.
Illustrate that the inventive method is superior relative to existing method with reference to the example of a specific industrial process
Property and reliability.The process data comes from the experiment of the U.S. Tennessee-Yi Siman (TE) chemical process, and prototype is Yi Siman chemical industry
One actual process flow of workshop.At present, TE processes are because of the complexity of its flow, as a standard test platform
It is widely used in fault detect research.Whole TE processes include 22 measurands, 12 performance variables and 19 composition measurements
Variable.The data gathered are divided into 22 groups, including the data set under 1 group of nominal situation and 21 groups of fault datas.And at this
In a little fault datas, it is known fault type to have 16, the changing of such as cooling water inlet temperature or feed constituents, it is valve viscous,
Kinetics drift etc., also 5 fault types are unknown.In order to be monitored to the process, choose as shown in table 1
33 process variables, next specific implementation step of the present invention is explained in detail with reference to the TE processes.
Table 1:TE process monitoring variables.
Sequence number |
Variable description |
Sequence number |
Variable description |
Sequence number |
Variable description |
1 |
Material A flow |
12 |
Separator liquid level |
23 |
D material inlet valves position |
2 |
Material D flows |
13 |
Separator pressure |
24 |
E material inlet valves position |
3 |
Material E flows |
14 |
Separator bottom of towe flow |
25 |
A material inlet valves position |
4 |
Combined feed flow |
15 |
Stripper grade |
26 |
A and C material inlet valves position |
5 |
Circular flow |
16 |
Pressure of stripping tower |
27 |
Compressor cycle valve location |
6 |
Reactor feed |
17 |
Stripper bottom rate |
28 |
Empty valve location |
7 |
Reactor pressure |
18 |
Stripper temperature |
29 |
Separator liquid phase valve location |
8 |
Reactor grade |
19 |
Stripper upper steam |
30 |
Stripper liquid phase valve location |
9 |
Temperature of reactor |
20 |
Compressor horsepower |
31 |
Stripper steam valve position |
10 |
Rate of evacuation |
21 |
Reactor cooling water outlet temperature |
32 |
Reactor condensate flow |
11 |
Separator temperature |
22 |
Separator cooling water outlet temperature |
33 |
Condenser cooling water flow |
(1) process data under collection TE process object nominal situations, and choose 960 normal data composition matrix X ∈
R960×33, it is standardized and obtained
(2) it is using ICA algorithmICA models are set up, i.e.,:And initialize k=1.
(3) matrix is assumedMiddle kth column data missing, remaining available column composition matrix Xk∈R960×32, and utilize following institute
Show that formula calculates the estimate for obtaining independent element matrix
In above formula, Ak∈R32×28To remove the matrix obtained by row k in hybrid matrix A;
(4) actual value S and estimate are calculatedBetween errorAnd calculating matrix FkCovariance matrix
Ck=Fk TFk/(n-1);
Because the object that the inventive method is monitored is error Fk, and that the monitoring of traditional IC A methods is independent element S, spy is to F1
The data of middle first row and first row in independent element matrix S carry out Gaussian Profile inspection, are as a result shown in Fig. 2.If being surveyed
It is then straight line to try the scatter diagram in the strict Gaussian distributed of data, Fig. 2.It will be apparent that error F in the inventive method1Closely
Like Gaussian distributed, and in traditional IC A methods due to extraction be non-gaussian independent element, Gauss point is not just met certainly
Cloth.It can also illustrate from this contrast, the composition of non-gaussian can dexterously be converted into approximately obeying Gauss by the inventive method
The error of distribution.So, the control limit that the inventive method is determined can just be obtained according to chi square distribution point.
(5) calculating matrix CkCharacteristic vector α corresponding to eigenvalue of maximumk∈R28×1, juxtaposition
(6) k < m are judgedIf so, then putting return to step after k=k+1 (3);If it is not, then off-line modeling is completed and implemented
Line malfunction monitoring;
To test the superiority in fault detect of the inventive method, to monitor the mean failure rate of 21 kinds of failures of TE processes
Detect exemplified by success rate, contrast the inventive method and traditional fault detect effect based on ICA methods.The test data has 960
Individual sample composition, its preceding 160 sample is nominal situation down-sampling, and rear 800 samples are sampled for fault condition.
1. the sampled data y at production process object newest moment is gatherednew∈R1×33, it is carried out and X same standards
Processing is obtained
2. sample vector is calculatedThe actual value of corresponding independent element vectorAnd initialize k=1;
3. sample vector is assumedIn k-th variable data missing, willThe middle new vector of remainder data composition
And utilize formulaCalculate the estimate for obtaining independent element vector
4. the error between the actual value and estimate of independent element vector is calculated
5. monitoring and statisticses amount Q is calculated according to formula as followsk:
Qk=(fkαk)2 (2)
7. k < 33 are judgedIf so, then putting after k=k+1 return to step 3.;If it is not, then performing step 8.;
8. Q=max { Q are put1, Q2..., Q33After, according to conditionWhether decision-making failure occurs.
Mean failure rate rate of failing to report of the present invention hair with traditional IC A methods for 21 kinds of fault types of TE processes is shown in Fig. 3
In, it is found that the mean failure rate rate of failing to report of the inventive method is significantly lower than traditional IC A methods.Therefore, the inventive method is improved
The fault detect performance of nongausian process monitoring method based on ICA.
Above-described embodiment is only used for explaining the present invention, rather than limits the invention, in the spirit and power of the present invention
In the protection domain that profit is required, any modifications and changes made to the present invention are both fallen within protection scope of the present invention.