Disclosure of Invention
Technical problem to be solved by the invention
In patent document 1, as described in paragraph 0005, "a nonlinear dynamic simulation model which can be made to sufficiently reflect the influence of aged deterioration, damage, or the like, which changes the correlation between a measurable item and an unmeasurable item" is described, patent document 1 describes an invention in which a nonlinear dynamic simulation model is tuned in sequence, an unmeasurable item of an engine is estimated from the measurable item, and the estimated result is used to control a gas turbine engine, not to perform early detection of an abnormality of the engine and diagnosis of the cause thereof.
Patent document 2 discloses an invention for simultaneously estimating at least two flight parameters related to each other by a flight mechanics equation by extending a kalman filter and for controlling the flight of an aircraft, and does not disclose early detection of an abnormality of an engine and diagnosis of the cause thereof.
Patent document 3 relates to an improvement of a kalman filter in a process control system for a chemical process, a petroleum process, or the like, and is not an invention for performing early detection of an abnormality of an engine and diagnosis of the cause thereof.
Accordingly, an object of the present invention is to provide an engine abnormality diagnosis method, an engine abnormality diagnosis program, and an engine abnormality diagnosis system that enable early detection of an abnormality of an engine and diagnosis of a cause thereof.
Solution to the above technical problems
An abnormality diagnosis method for an engine corresponding to the description of the embodiment 1 is a method for performing abnormality diagnosis on an abnormality of the engine by using a mathematical engine model, and is characterized by comprising an initial state quantity acquisition step of acquiring an initial state quantity of the engine model, an engine model utilization step of applying the initial state quantity to the engine model and utilizing the engine model, an engine state estimation step of calculating a state of the engine based on the initial state quantity and obtaining an estimated state quantity by using the engine model, a measured state quantity acquisition step of acquiring a measured state quantity of the engine, a Kalman filtering step of applying a residual error of the acquired measured state quantity and the calculated estimated state quantity to a nonlinear Kalman filter, a repetition step of applying a Kalman gain obtained by applying the obtained Kalman gain to the nonlinear Kalman filter to the engine model, and repeating the engine state estimation step, the measured state quantity acquisition step and the Kalman filtering step, a correlation calculation step of calculating a correlation of the measured state quantity or the residual error when applied to the nonlinear Kalman filter, a factor analysis step of performing factor analysis on the correlation of the measured state quantity or the residual error, a factor obtaining a factor load quantity, a detection step of the factor, a detection of the residual error, and a machine learning step of diagnosing the abnormality, and a machine learning step of the abnormality load, and a machine learning step of the abnormality, and an abnormality diagnosis based on the abnormality factor.
According to the present invention described in claim 1, the abnormality of the engine can be detected early based on the calculated factor score by performing factor analysis using the measured state quantity or the residual error between the measured state quantity and the calculated estimated state quantity. Further, the factor load amount can be applied to machine learning to diagnose the cause of the abnormality of the engine.
The present invention described in claim 2 is characterized in that the model updating step is further executed, and the engine model is updated by applying the result obtained in the kalman filtering step or the result obtained by processing the acquired measurement state quantity to the engine model utilization step.
According to the present invention described in claim 2, the engine model can be updated and the calculation accuracy of the estimated state quantity can be kept high at all times.
The present invention described in claim 3 is characterized in that the correlation of the measurement state quantity or the residual error in the correlation calculation step is calculated based on the correlation matrix.
According to the invention described in claim 3, the calculation accuracy of the correlation between the measurement state quantity and the residual error can be improved by simple calculation.
In the present invention described in claim 4, in the factor analysis step, a Singular Value Decomposition (SVD) is performed based on a covariance matrix as a correlation matrix, thereby deriving the factor load.
According to the invention described in claim 4, it is possible to extract essential matters without being limited by the shape of the covariance matrix, and detect abnormality of the engine early.
The invention described in claim 5 is characterized in that the machine learning uses self-organizing map (SOM).
According to the invention described in claim 5, the cause of the abnormality of the engine can be classified by using self-organizing map (SOM) which is an unsupervised machine learning.
The invention described in claim 6 is characterized in that the initial state quantity acquired in the initial state quantity acquisition step is a load (Q p) of the engine and a fuel supply quantity including a fuel pump rack position (h p).
According to the invention described in claim 6, the estimated state quantity can be obtained based on the load (Q p) of the engine, which is important in estimating the state of the engine, and the fuel supply quantity including the fuel pump rack position (h p).
The invention described in claim 7 is characterized in that the measurement state quantity acquired in the measurement state quantity acquisition step is the rotation speed (n e) of the engine.
According to the invention described in claim 7, the engine speed (n e) which is a high-probability measure for the engine can be used for abnormality diagnosis of the engine, and the measurement accuracy can be improved.
The present invention described in claim 8 is characterized in that the supercharger rotation speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s) and the exhaust gas temperature (T e) are obtained as estimated state amounts in the engine state estimating step.
According to the invention described in claim 8, it is possible to obtain the diagnosis result of the supercharger rotation speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), or the exhaust gas temperature (T e) which are useful for estimating the state of the engine.
The abnormality diagnosis program of the engine according to the description of claim 9 is a program for performing abnormality diagnosis of an abnormality of the engine using a mathematical engine model, and is characterized in that an initial state quantity acquisition step, an engine model utilization step, an engine state estimation step, a measurement state quantity acquisition step, a kalman filter step, a repetition step, a correlation calculation step, a factor analysis step, an abnormality detection step, a machine learning application step, an abnormality diagnosis step, and an output step in the abnormality diagnosis method of the engine are executed by a computer.
According to the invention described in claim 9, the abnormality of the engine can be detected early based on the calculated factor score by performing factor analysis using the measured state quantity or the residual error between the measured state quantity and the calculated estimated state quantity. Further, the factor load amount can be applied to machine learning to diagnose the cause of the abnormality of the engine.
An abnormality diagnosis system for an engine according to claim 10 is characterized by comprising an engine, a condition input means for inputting an initial state quantity of an engine model, a state quantity measuring means for measuring a state of the engine to obtain a measured state quantity, a computer for executing an abnormality diagnosis method for the engine or an abnormality diagnosis program for the engine, and an information providing means for providing abnormality information including a diagnosis result of an abnormality of the engine, which is output from the computer.
According to the invention described in claim 10, it is possible to provide abnormality information including results of early detection of an abnormality of an engine and diagnosis of a cause thereof by a computer.
The invention described in claim 11 is characterized in that the updating of the engine model is performed by a computer.
According to the invention described in claim 11, the engine model is updated by the computer, whereby the accuracy of calculating the estimated state quantity can be easily improved.
The invention described in claim 12 is characterized in that the rotation speed (n e) of the engine is obtained as the measurement state quantity by the state quantity measuring means.
According to the invention described in claim 12, the engine speed (n e) which is a high-probability measure for the engine can be used for abnormality diagnosis of the engine, and the measurement accuracy can be improved.
The invention described in claim 13 is characterized in that the information providing means provides the results of at least 1 of the supercharger speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s) and the exhaust temperature (T e) of the engine as the diagnosis result of the abnormality.
According to the invention described in claim 13, it is possible to obtain the diagnosis result of the supercharger rotation speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), or the exhaust gas temperature (T e) which are useful for estimating the state of the engine.
The invention described in claim 14 is characterized by comprising an abnormality time control means for controlling the engine at the time of abnormality based on the output of the abnormality information.
According to the invention described in claim 14, by controlling the engine at the time of abnormality, it is possible to prevent the abnormality of the engine from becoming serious or causing a failure.
The invention described in claim 15 is characterized in that the abnormality information is provided using the man-machine interaction means as the information providing means.
According to the invention described in claim 15, by providing the abnormality information of the engine from the man-machine interaction means, a crew member or the like can cope with the abnormality promptly and appropriately.
The invention described in claim 16 is characterized by comprising a transmission means for transmitting the abnormality information provided by the information providing means to another place.
According to the invention described in claim 16, the diagnosis result including the abnormality of the engine can be obtained in real time even at a location remote from the engine.
The invention described in claim 17 is characterized by comprising a connection means for connecting the state measuring means, the computer, and the information providing means on line.
According to the invention described in claim 17, it is possible to transmit and provide a diagnosis result including an abnormality of the engine on line in real time.
Effects of the invention
According to the abnormality diagnosis program for an engine of the present invention, the abnormality of the engine can be detected early on based on the calculated factor score by performing factor analysis using the measured state quantity or the residual of the measured state quantity and the calculated estimated state quantity. Further, the factor load amount can be applied to machine learning to diagnose the cause of the abnormality of the engine.
Further, in the case where the model updating step of applying the result obtained in the kalman filtering step or the result obtained by processing the acquired measurement state quantity to the engine model utilizing step to update the engine model is further performed, the engine model can be updated so that the calculation accuracy of the estimated state quantity is always kept in a high state.
In addition, in the case of performing calculation of correlation of residuals in the correlation calculation step based on the correlation matrix, the calculation accuracy of correlation of the measurement state quantity or residuals can be improved by simple calculation.
In the factor analysis step, when the factor load is derived by performing Singular Value Decomposition (SVD) based on the covariance matrix as the correlation matrix, it is possible to extract essential content without being limited by the shape of the covariance matrix, and detect the abnormality of the engine early.
In addition, in the case of using self-organizing map (SOM) as machine learning, the cause of the abnormality of the engine can be classified using self-organizing map (SOM) as unsupervised machine learning.
Further, in the case where the initial state quantity acquired in the initial state quantity acquisition step is the load (Q p) of the engine and the fuel supply quantity including the fuel pump rack position (h p), the estimated state quantity can be obtained based on the load (Q p) of the engine and the fuel supply quantity including the fuel pump rack position (h p) that are vital in estimating the state of the engine.
In addition, when the measurement state quantity acquired in the measurement state quantity acquisition step is the rotational speed (n e) of the engine, the rotational speed (n e) of the engine, which has a high chance of being measured for the engine, can be used for abnormality diagnosis of the engine, and the measurement accuracy can be improved.
Further, when the supercharger rotation speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), and the exhaust gas temperature (T e) are obtained as the estimated state amounts of the engine state estimating step, the diagnosis result of the supercharger rotation speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), or the exhaust gas temperature (T e) that are useful for estimating the state of the engine can be obtained.
Further, according to the abnormality diagnosis program of the engine of the present invention, the abnormality of the engine can be detected early based on the calculated factor score by performing factor analysis using the measured state quantity or the residual of the measured state quantity and the calculated estimated state quantity. Further, the factor load amount can be applied to machine learning to diagnose the cause of the abnormality of the engine.
Further, according to the abnormality diagnosis system for an engine of the present invention, it is possible to provide abnormality information including results of performing early detection of an abnormality of the engine and diagnosis of a cause thereof, using a computer.
In addition, in the case where the engine model is updated by the computer, whereby the calculation accuracy of the estimated state quantity can be easily improved.
In addition, when the rotational speed (n e) of the engine is obtained as the measurement state quantity by the state quantity measuring means, the rotational speed (n e) of the engine, which has a high chance of being measured for the engine, can be used for abnormality diagnosis of the engine, and the measurement accuracy can be improved.
Further, in the case where the result of at least 1 of the supercharger speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), and the exhaust gas temperature (T e) of the engine is provided as the diagnosis result of the abnormality by the information providing unit, the diagnosis result of the supercharger speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), or the exhaust gas temperature (T e) useful in estimating the state of the engine can be obtained.
Further, in the case of providing an abnormality time control unit that controls the engine at the time of abnormality based on the output of the abnormality information, by controlling the engine at the time of abnormality, it is possible to prevent the abnormality of the engine from becoming serious or causing a failure.
In addition, in the case where abnormality information is provided using the man-machine interaction unit as the information providing unit, by providing abnormality information of the engine from the man-machine interaction unit, a crew member or the like can cope with the abnormality promptly and appropriately.
Further, in the case of providing the transmission means for transmitting the abnormality information provided by the information providing means to another place, the diagnosis result including the abnormality of the engine can be obtained in real time even in a place remote from the engine.
In addition, in the case of the connection unit that connects the state quantity measuring unit, the computer, and the information providing unit on-line, the diagnosis result including the abnormality of the engine can be transmitted and provided on-line in real time.
Detailed Description
An abnormality diagnosis method for an engine, an abnormality diagnosis program for an engine, and an abnormality diagnosis system for an engine according to an embodiment of the present invention are described below.
Fig. 1 is a block diagram of an abnormality diagnosis system of an engine.
The engine abnormality diagnosis system diagnoses an abnormality of an engine 1 mounted on a ship or the like using a mathematical engine model 10.
The engine abnormality diagnosis system includes a condition input unit 2 for inputting an initial state quantity of an engine model 10, a state quantity measuring unit 3 for measuring a state of an engine 1 and obtaining a measured state quantity, a computer 4 for executing an engine abnormality diagnosis method or program, an information providing unit (human-machine interaction unit: HMI) 5 for providing abnormality information including a diagnosis result of an abnormality of the engine 1 outputted by the computer 4, an abnormality time control unit 6 for controlling the engine 1 at the time of abnormality based on an output of the abnormality information, a transmitting unit 7 for transmitting the abnormality information provided by the information providing unit 5 to other places, and a connecting unit 8 for connecting the respective devices on line. The engine model 10 is preferably installed in the computer 4 corresponding to the engine 1 from the beginning, but may be changed in the middle via the condition input means 2 or the like when, for example, a part or all of the engine 1 is changed to a different state in association with maintenance of a ship or the like.
The connection means 8 is, for example, a router, LAN, or the like, and connects the state quantity measuring means 3, the computer 4, and the information providing means 5 on line. Thereby, the diagnosis result including the abnormality of the engine 1 can be transmitted and provided on line in real time. The online connection can be made by wireless or wired connection via the connection unit 8.
The transmission unit 7 is provided in the computer 4. The computer 4 further includes a control unit 11, an initial state quantity acquisition unit 12, an engine state estimation unit 13, a measurement state quantity acquisition unit 14, a kalman filter unit 15, a repetition unit 16, a correlation calculation unit 17, a factor analysis unit 18, an abnormality detection unit 19, a machine learning application unit 20, an abnormality diagnosis unit 21, an engine model update unit 22, a main memory 23, an auxiliary memory 24, an engine model utilization unit 27, an output unit 28, and the like.
The auxiliary memory 24 is, for example, a hard disk or the like. The auxiliary memory 24 stores the engine model 10, the factor load space 25, and the mechanical device failure database 26. The engine model 10 is a model constructed in advance based on the specifications and characteristics of the engine 1. In the factor load amount space 25, factor load amount data is accumulated from the detection of abnormality of the engine 1. In the mechanical failure database 26, data collected by simulating the failure of the engine 1 by a simulation program is collected. In addition, if there is an engine state value at the time of actual failure, the engine state value may be collected in the mechanical failure database 26.
The condition input unit 2 is a mouse, a keyboard, a touch panel, or the like. The operator or user 101 of the computer 4 inputs the initial state quantity using the condition input unit 2. As the initial state quantity, the load (Q p) of the engine 1 and the fuel supply quantity including the fuel pump rack position (h p) are preferably input. Thus, the estimated state quantity can be obtained based on the load (Q p) of the engine 1, which is important in estimating the state of the engine 1, and the fuel supply quantity including the fuel pump rack position (h p). The input initial state quantity is transmitted to the initial state quantity acquisition unit 12 of the computer 4 and acquired. Further, when the operating condition is changed sufficiently to change the engine model 10, a condition signal can also be input through the condition input unit 2.
The state quantity measuring unit 3 is various sensors or the like. In the state quantity measuring unit 3, the rotation speed (n e) of the engine 1 is preferably obtained as a measured state quantity. This makes it possible to use the rotation speed (n e) of the engine 1, which is a high-probability measurement for the engine 1, for abnormality diagnosis of the engine 1, and to improve the measurement accuracy. In addition to the measurement state quantity measured by the state quantity measuring means 3, there are, for example, the scavenging pressure (P s) of the engine 1, the exhaust gas temperature (T e), the load (Q p) of the engine 1, and the like. The measurement state quantity measured by the state quantity measuring unit 3 is sent to the measurement state quantity acquiring section 14 of the computer 4. The measurement state quantity may be, in addition to the measurement value itself, an average value of a certain period of the measurement value, a difference from the average value, or the like, which is processed based on the measurement value.
The output unit 28 outputs the diagnosis result of the engine 1 obtained by the computer 4 to the transmission unit 7, the information providing unit (man-machine interaction unit) 5, and the abnormality-time control unit 6.
The information providing unit 5, the abnormality-time control unit 6, and the transmitting unit 7 may be provided outside the computer 4.
The information providing unit 5 preferably provides the result of at least 1 of the supercharger speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), and the exhaust gas temperature (T e) of the engine 1 as a diagnosis result of abnormality of the engine 1. As a result, the diagnosis result for the supercharger rotation speed (n tc), the scavenging pressure (P s), the scavenging temperature (T s), or the exhaust gas temperature (T e) which are useful in estimating the state of the engine 1 can be obtained. Further, the information providing unit 5 can provide not only the diagnosis result of the abnormality of the engine 1 but also all the information associated with the abnormality including the abnormality detection information.
The transmission unit 7 transmits the outputted diagnosis result to a device provided at a location different from the computer 4 through a wired or wireless LAN via the connection unit 8. Thus, even in a place remote from the engine 1, abnormality information including the diagnosis result of the abnormality of the engine 1 can be obtained in real time. In fig. 1, a bridge 100 and a user 101 on land such as a ship company are shown as places for receiving abnormality information. For example, in the case where the computer 4 is in the engine room, the information providing unit 5 transmits the abnormality information to the bridge 100 through the in-ship LAN.
The information providing unit (man-machine interaction unit) 5 is, for example, a monitor, a speaker, or the like. By providing abnormality information of the engine 1 from the information providing unit (man-machine interaction unit) 5, a crew member or the like can cope with the abnormality promptly and appropriately. The information providing unit 5 includes, in addition to the man-machine interaction unit, a storage unit that temporarily stores abnormality information, a transmission unit that transmits abnormality information to, for example, a smart phone, and other units related to the provision of information.
The abnormality-time control unit 6 controls the engine 1 automatically at the time of abnormality or according to an operation from a crew member based on the abnormality detection result or the diagnosis result of the abnormality. By controlling the engine 1 at the time of abnormality, the abnormality of the engine 1 can be prevented from becoming serious or causing a malfunction. The information or signal supplied to the abnormality time control unit 6 may be unprocessed information or signal of the information supplied to the information supply unit 5.
Fig. 2 is a flowchart of an engine abnormality diagnosis method, and fig. 3 is a schematic diagram of an engine abnormality diagnosis. Since the abnormality diagnosis method of the engine can be provided as a program, the abnormality diagnosis program of the engine will be described below as a program for causing a computer to execute each step in the abnormality diagnosis method of the engine.
When the personal computer starts executing the abnormality diagnosis program of the engine, the control unit 11 reads the engine model 10 stored in the auxiliary memory 24 (engine model reading step S1).
After the engine model reading step S1, the initial state quantity acquisition unit 12 acquires the initial state quantity of the engine model 10 input by the condition input unit 2 (initial state quantity acquisition step S2).
After the initial state quantity acquisition step S2, the control unit 11 applies the initial state quantity to the read engine model 10 in the engine model utilization unit 27, and utilizes the engine model 10 (engine model utilization step S3). In the engine model utilization step S3, the engine model 10 is initially set or updated. In order to use the engine model 10, it is necessary to apply an arbitrary initial state quantity, and if an initial state quantity (for example, a load or a fuel quantity) as close as possible to the current state is applied in the engine model using step S3 of using the engine model 10, it is possible to realize the use of the engine model 10, such as a reduction in the calculation time in the engine model 10, an improvement in the accuracy of the estimation calculation based on the engine model 10, or the like. In addition, in the engine model using step S3, the engine model 10 can be updated by using the residual error input in the kalman filtering step S6 or the result obtained by processing the acquired measurement state quantity, and the engine model 10 can faithfully reproduce the engine 1 of the real object and use the engine.
The engine state estimating unit 13 calculates the state of the engine 1 based on the initial state quantity by using the engine model 10 and obtains an estimated state quantity (engine state estimating step S4).
Further, the measurement state quantity acquisition section 14 acquires the measurement state quantity of the engine 1 obtained by the measurement by the state quantity measurement unit 3 (measurement state quantity acquisition step S5).
The kalman filter unit 15 inputs the residual error between the acquired measurement state quantity and the calculated estimated state quantity to a nonlinear kalman filter (kalman filter step S6). In the kalman filtering step S6, the state estimation and the estimation of the model parameters are performed.
After the kalman filtering step S6, the engine model updating section 22 determines whether or not the engine model 10 needs to be updated (model update determination step S7).
When the model update determination step S7 determines that "yes" is required, that is, when the engine model 10 needs to be updated, the engine model updating unit 22 applies the result obtained in the kalman filtering step S6 or the result obtained by processing the acquired measurement state quantity to the engine model using step S3, and updates the model parameters to update the engine model 10 (model updating step S8). By updating the engine model 10, the calculation accuracy of the estimated state quantity can be kept always in a high state in accordance with the aged deterioration or the like of the engine 1. Further, the engine model 10 is updated by the computer 4, whereby the calculation accuracy of the estimated state quantity can be easily improved. The determination in the model update determination step S7 is performed by setting a threshold value for the model parameter in advance.
On the other hand, when the model update determination step S7 is determined as no, that is, when the engine model update unit 22 determines that the engine model 10 does not need to be updated, the repeating unit 16 determines whether or not a predetermined time has elapsed (time elapsed determination step S9). The repetition unit 16 is divided into, for example, 0.1 seconds, and repeatedly performed at k, k+1, and k+2.
When the time lapse determination step S9 is "no", that is, when the predetermined time has not elapsed, the repeating unit 16 applies the kalman gain obtained by the nonlinear kalman filter to the engine model 10, and repeats the engine state estimation step S4, the measurement state quantity acquisition step S5, and the kalman filter step S6 (repeats step S10).
In this way, the update of the engine model 10 and the state estimation are repeated using two functions of the kalman filter, such as the state estimation and the model parameter estimation. In addition, when the measured state quantity is reliable, the model parameters are identified using a tracking filter, and the kalman filter can perform only state estimation.
The nonlinear kalman filter is preferably an unscented kalman filter or an extended kalman filter. This makes the kalman gain more appropriate for the engine 1 as a nonlinear system, and improves the accuracy of calculating the estimated state quantity.
On the other hand, when the time lapse determining step S9 determines that "yes", that is, the repeating unit 16 determines that the predetermined time has elapsed, the correlation calculating unit 17 calculates the correlation of the residual obtained when the input to the nonlinear kalman filter is performed (correlation calculating step S11). The calculation of the correlation of the residuals in the correlation calculation step S11 is preferably performed based on a correlation matrix. This can improve the calculation accuracy of the correlation of the residual errors by simple calculation.
In addition, the correlation may be calculated using the acquired measurement state quantity instead of the residual error obtained when the input to the nonlinear kalman filter is performed.
After the correlation calculation step S11, the factor analysis unit 18 performs factor analysis on the correlation of the residuals to determine the factor load amount (factor analysis step S12).
Instead of the correlation of the residual error, the correlation of the acquired measurement state quantity may be used to perform factor analysis to determine the factor load quantity.
After the factor analysis step S12, the abnormality detection unit 19 calculates a factor score from the factor load amount, and detects an abnormality (abnormality detection step S13). The abnormality detected in the abnormality detection step S13 may be outputted as abnormality information.
In the factor analysis step S12, singular Value Decomposition (SVD) is performed based on the covariance matrix as the correlation matrix, thereby deriving the factor load amount. Thus, it is possible to extract essential content without being limited by the shape of the covariance matrix, and to detect abnormality of the engine 1 early.
The factor load amount obtained in the factor analysis step S12 is accumulated in the factor load amount space 25 (factor load amount accumulating step S14). The machine learning application section 20 reads out the data stored in the mechanical device failure database 26 (mechanical device failure data reading out step S15), and applies the factor load amount to machine learning (machine learning application step S16). As machine learning, self-organizing map (SOM) is used. This makes it possible to clearly classify the cause of the abnormality of the engine 1 by the SOM that is the unsupervised machine learning. Further, as the machine learning algorithm, SVM (Supportvectormachine: support vector machine), fuzzy C-means (fuzzy C-means) and the like can be used in addition to SOM.
The abnormality diagnosis section 21 diagnoses an abnormality based on the machine learning (abnormality diagnosis step S17).
After the abnormality detection step S13 and the abnormality diagnosis step S17, the output unit 28 outputs abnormality information including the diagnosis result of the abnormality of the engine 1 (output step S18). The output of the abnormality information in the output step S18 may include abnormality detection information and incidental information in addition to the diagnosis result of the abnormality. The output destination is the information providing unit (man-machine interaction unit) 5, the abnormality-time control unit 6, and the transmitting unit 7 as described above.
The abnormality diagnosis of the engine 1 using the factor analysis will be described in detail below.
Fig. 4 is a conceptual diagram of factor analysis. The factor analysis is an analysis for searching for a hidden (unmeasurable) variable factor F, which is common to all the measurement values (measurement state amounts) y m and whose relationship is represented by a im. Which uses a linear relationship parameter a as shown in the following formula (1).
[ Number 1]
In the formula (1), f is a common factor, a im is a linear coefficient, and the remaining u i is measurement error or noise due to an unexplained factor.
Each measurement y m is linearly connected to a certain number of common factors f. The linear coefficient a im is called the factor load. Factor analysis refers to the exploration of hidden variables (factors), but the factors can also be considered as some kind of abnormality (cause of accident) when a measured value changes.
Fig. 5 is a diagram showing an example of factor analysis using measurement data. As shown in fig. 5, when an example of calculation of the factor load a and the main factor of a specific follow-up change based on the measured value is given as an example of factor analysis using the measured data Y, the measured value Y 1,y2,……ym represents, for example, the scavenging pressure, the exhaust gas temperature, and the engine load of the engine 1, and the intervals (for example, 0~t intervals) at a certain time are combined to create a matrix (fig. 5 a). The covariance matrix of this matrix was calculated, and R was obtained by dividing the standard deviation of each variable (fig. 5 (b)). Singular Value Decomposition (SVD) is performed on R to obtain singular value S. Next, the factor 1 load a is obtained (fig. 5 (c)). The value obtained by adding the squares of the respective factor 1 load amounts a and dividing by the sum of variances is a factor score D (index) (fig. 5 (D)).
The Singular Value Decomposition (SVD) is also performed on the correlation matrix of the covariance matrix to obtain the factor load in the 1 st stage, and the EM (ExpectationMaximization: expectation maximization) method is used to obtain the significant factor load having characteristics.
Fig. 6 is a diagram showing an example of the factor score, fig. 6 (a) shows the original factor score F1 (D1), and fig. 6 (b) shows the filtered factor score F1 (D1). Fig. 7 is a graph showing a change in the factor load amount of each measured value, where (a) of fig. 7 is the scavenging pressure, (b) of fig. 7 is the supercharger speed, (c) of fig. 7 is the exhaust gas temperature, and (d) of fig. 7 is the scavenging temperature. If the factor scores D1 (main indexes) are arranged in time series, for example, as shown in fig. 6, when an abnormality (some kind of change) occurs in the engine 1, such as when the flow rate of the cooling water in the air cooler of the engine 1 starts to decrease.
In other words, as shown in fig. 7, the information contained in the factor load amount matrix a indicates an abnormality caused by a certain change in the propulsion system. Further, the factor load amount (row of matrix a) represents the strength of the relationship between the propulsion system parameters as the element of the error, and represents the characteristic of the cause of the abnormality. Therefore, by machine learning the factor load amount using a machine learning algorithm, such as self-organizing map (SOM), the factor load amount can be used for the reason classification of the accident of the propulsion system. In addition, the factor score D1 may be used for early detection of abnormalities.
As shown in fig. 3, in the present invention, a kalman filter observer is used as the kalman filter unit 15, and factor analysis is performed using the residual error between the measured state quantity and the estimated state quantity. That is, in the present invention, as another method, the same factor analysis as described above is performed using the residual error E inherently calculated by the kalman filter unit 15 between the measured state quantity and the estimated state quantity obtained by the engine state estimating unit 13 instead of the measured value (measured state quantity) Y. The residual E is a deviation from the estimated state quantity, and reflects the deviation from the normal state if the estimated state quantity is considered to be the normal state. Therefore, it is possible to detect that some abnormality has occurred in the engine 1 based on the residual E.
The Kalman filter observer is based on a digitally twinned engine model 10. In the kalman filter observer, a residual error E of a measured state quantity obtained by a dynamic process of the engine 1 and an estimated state quantity calculated by a process of the engine model 10 based on the initial state quantity is input to a nonlinear kalman filter. Thereby obtaining the Kalman gain. Kalman gain is applied to the engine model 10 for mathematical process control of the engine model 10.
In this way, by monitoring the engine state using the engine model 10 as a digital twin model of the engine 1, it is possible to detect a failure of the engine 1 at an early stage and diagnose the cause.
Fig. 8 is a diagram showing an example of a mathematical model of an engine.
The left side of the arrow in fig. 8 is a diagram of the relation between the actual fuel supply system (fuel pump rack position (h p)) in the engine 1 and the measurement system of the rotational speed (n e) of the engine 1, etc., and shows the measurement points and measurement values in the engine 1. The right side in fig. 8 shows an engine model 10 as a mathematical model of the engine 1.
In fig. 8, the state quantity measuring unit 3 is shown by the english letters enclosed. The thermometer was defined as "T" surrounded by O, the manometer was defined as "P" surrounded by O, the tachometer was defined as "n" surrounded by O, and the axiometer was defined as "Q" surrounded by O. The load variation is measured by an axiom.
For each step (k, k+1, k+2), a measurement is measured, and each step calculation (estimation) is performed using engine model 10. In order to improve the estimation accuracy of the engine model 10, the engine model 10 is gradually corrected by acquiring the rotational speed (n e) of the engine 1 that can be measured most reliably and with high accuracy to calculate the kalman gain. This is the kalman filter.
In the mathematical model of the engine 1 shown in fig. 8, the behavior in the normal state can be represented by a nonlinear state space model. The nonlinear state space model is composed of an equation expressed by a state equation X, parameters expressed by a state quantity X, and inputs expressed by an input quantity u. The right side of the state equation X is expressed by functions shown by a box at the right center, and the relation between the state quantity n e、ntc、Ps、Te、Pe、Gf and the input quantity h p、Qp is expressed by 5 equations.
For example, the output function H of each system function F and observation equation y (T) is shown taking the fuel pump rack position (H p) and the load of the engine (Q p) as inputs, and taking the rotation speed (n e) of the engine 1, the supercharger rotation speed (n tc), the scavenging pressure (P s), the exhaust pressure (P e), the exhaust temperature (T e), and the fuel flow rate (G f) as states (x) and outputs (y).
The observation value y output in the example of fig. 8 is equal to the state quantity x.
Fig. 9 is a diagram showing parameters of the engine model.
Examples of the model parameters include a load (Q p) of an engine such as a propeller torque, an engine torque (Q e), a moment of inertia (I e、Itc), a fuel pump rack position (h p), Engine speed (n e), supercharger speed (n tc), atmospheric pressure (P a), atmospheric temperature (T a), Scavenging pressure (P s), scavenging temperature (T s), maximum compression pressure in cylinder (P c), maximum combustion pressure in cylinder (P z), Average effective pressure in cylinder (P i), scavenging tank volume (V a.r), exhaust tank volume (V e.r), thermodynamic constant (R a、Re、ke、Cpe、Cpa), Cooling water temperature (T w), compressor outlet temperature (T c), discharge pressure (P e), discharge temperature (T e), Turbine outlet temperature (T out), turbine outlet pressure (P out), fuel flow (G f), scavenge flow (G a), Compressor air flow (G c), exhaust flow (G e).
Fig. 10 is a diagram showing concepts and calculation formulas of a prediction (estimation) step (kalman filter step S6) and an update (correction) step (model update step S8) of the kalman filter.
If the difference between the engine model 10 and the entity and the uncertainty of the measurement performed by the state quantity measuring unit 3 are taken into consideration, an error (residual) may occur between the estimated state quantity obtained based on the engine model 10 and the measured state quantity. This error is calculated, corrected by measuring the state quantity, and the estimated state quantity is made as close as possible to the correct value, which is an unscented kalman filter as a nonlinear kalman filter. The basis of the unscented kalman filter is shown in fig. 10.
By applying a kalman filter, the uncertainty of measurement and modeling is taken into account in discrete sampling times k, and the behavior of the propulsion system is repeatedly represented with the calculated error (formula (2) below).
[ Number 2]
In the normal operation, the error distribution is regarded as a normal distribution of 0 average. To detect an abnormal state, an error generated by the kalman filter is provided to a factor analysis.
Fig. 11 is a diagram showing a relationship between a kalman filter and factor analysis.
Parameters a of the factor analysis model (y=af+u) are estimated from the correlation matrix (covariance matrix). As described above, the kalman filter observer performs covariance estimation each time based on the digitally twinned engine model 10, and uses the kalman gain as an indicator (indicator) of which state quantity should be corrected.
Fig. 12 is a diagram showing an example of abnormality detection by factor score.
Fig. 12 shows an example of a rapid detection of an abnormality in the abnormality diagnosis system of the engine by performing an experiment of simulating the clogging of the supercharger suction filter of the actual engine 1. The horizontal axis of the graph indicates the number of samples, and the 1 st time is 0.1 second. Although the supercharger suction filter gradually closes and the pressure loss increases, the factor score F1 rapidly increases in the initial stage of the pressure loss starting to increase, so that an abnormality can be detected.
In this way, by performing factor analysis using the residuals of the measured state quantity and the calculated estimated state quantity, it is possible to detect an abnormality of the engine 1 early on the basis of the calculated factor score. Further, the factor load amount can be applied to machine learning to diagnose the cause of the abnormality of the engine 1. Further, the computer 4 can provide abnormality information including the results of early detection of abnormality of the engine 1 and diagnosis of the cause thereof.
The respective components and peripheral units of the computer 4 may be provided externally or internally as appropriate, or may share the functions of the computer 4 by a plurality of computers, or may be partially provided as discrete circuits.
Industrial applicability
The present invention can perform, for example, early detection and diagnosis of an abnormality of an engine of a launch vessel, and can obtain a diagnosis result including an abnormality of the engine in real time even in a remote place, thereby contributing to safe and efficient sailing. The present invention can also be used for early detection of an abnormality of an engine other than a ship and diagnosis of the abnormality.
Description of the reference numerals
1 Engine
2 Condition input unit
3 State quantity measuring unit
4 Computer
5 Information providing unit (man-machine interaction unit)
6 Abnormal time control unit
7 Transmitting unit
8 Connection unit
10 Engine model
S2 initial State quantity acquisition step
S3 engine model utilization step
S4 engine state estimation step
S5 measurement state quantity acquisition step
S6 Kalman filtering step
S8 model updating step
S10 repeating the steps
S11 correlation calculation step
S12 factor analysis step
S13 abnormality detection step
S16 machine learning application step
S17 abnormality diagnosis step
S18, outputting.