The present invention relates to a technology to assist improving diagnostic accuracy in diagnosing for abnormality of a machine.
Machine maintenance work is necessary to make a machine, such as a gas engine, an elevator, an excavation machine, and an architecture equipment operate at all times. As one of technologies that are effective for maintenance work, there is a technology that collects sensor data from sensors installed on respective parts of a machine, diagnoses for abnormality of the machine from the collected sensor data, and, if an abnormality has been found, analyzes a cause thereof.
To implement that technology, a method is available that represents sensor data on a machine and a data appearance frequency with a scatter diagram or a histogram and checks for abnormality of the machine from an outlier in an appearance frequency distribution thus obtained.
For example,
While performing such learning and diagnosis, if a change is made to a parameter such as the number of clusters and a period when the machine was operating normally, a change occurs like an abnormality degree 16200 in
To improve the diagnostic accuracy of abnormality diagnosis of the graph 15400, a check is made whether large and small abnormality degrees correspond with actual abnormality and normality and, if not, it is required to modify a diagnostic parameter such as the number of clusters. In particular, from a maintenance history recorded by a maintenance person 15200, a check is made whether an abnormality degree becomes high for a period when the machine was abnormal. Then, as in a graph 15400, if a period when an abnormality degree is too low or a period when an abnormality degree is too high is found, whereas there remains a record indicating abnormality for that period in the maintenance history, a parameter is modified. When the parameter has been modified successfully, the abnormality degree for a period when the abnormality degree is too low or too high is modified and the diagnostic accuracy can be improved.
In this operation of modifying a parameter, it is required to perform a checking operation repeatedly; once a parameter has been modified, a check is made whether the diagnostic accuracy can be improved by comparing a graph 15500 and a graph 15400 before modification; and, when a parameter is modified again, a check is made whether the diagnostic accuracy can be improved.
A data display device to solve above-mentioned problems are, for example, found in Patent Document 1. This Document concerns an invention that selects a diagnostic parameter when calculating an abnormality degree, calculates an abnormality degree, and displays its trend data. Using this invention, by carrying out the above operation of modifying a parameter, it is possible to improve diagnostic accuracy.
If there are a lot of data items of trend data of abnormality degree, the invention of Patent Document 1 involves a problem in which it is not known what period of abnormality degree trend for which an abnormality degree has been improved by modifying a parameter, unless scrolling a graph and checking.
To solve the above-described problem, a data display system of the present invention includes a storage unit that stores data from sensors installed on a machine; a parameter setting unit that accepts input of a parameter for processing the data; a diagnosis unit that displays, on a display unit, results of processing of the data allowed to be compared before and after modifying a parameter; and a display data filtering calculation unit that changes a scope of data to display for comparison by selecting a criterion to filter data to display by an analysis operator to analyze the data.
The data display system of the present invention is further wherein the display data filtering calculation unit changes the scope of data to display according to an extent to which a parameter is modified, specified as a criterion to filter data to display, and a result of processing of the data by modifying the parameter.
The data display system of the present invention is further wherein the display data filtering calculation unit takes it as a criterion to filter data to display that a value change has occurred in a trend graph before and after parameter adjustment.
The data display system of the present invention is further wherein the display data filtering calculation unit takes a change of an abnormality degree change rate before and after parameter adjustment as a criterion to filter data to display.
The data display system of the present invention is further wherein the display data filtering calculation unit takes a ratio of a change amount of abnormality degree to a change amount of a parameter as a criterion to filter data to display.
The data display system of the present invention is further wherein the display data filtering calculation unit takes it as a criterion to filter data to display that an abnormality degree has been made larger or smaller than a specified threshold value by the parameter adjustment.
The data display system of the present invention is further wherein the display data filtering calculation unit takes it as a criterion to filter data to display that an abnormality degree change before and after parameter adjustment is not monotonically increasing or decreasing.
The data display system of the present invention is further wherein the display data filtering calculation unit takes it as a criterion to filter data to display that the machine is in a specified operating mode.
The data display system of the present invention is further wherein the specified operating mode is a transient period during startup of the machine or an idling period.
According to the data display system of the present invention, abnormality degree tread data narrowed to only abnormality degree data that satisfies a specified condition is displayed. This enables it to quickly find a period in which an abnormality degree graph has changed before and after modifying a diagnostic parameter. Thereby, assisting in an operation of improving diagnostic accuracy by modifying a diagnostic parameter can be realized.
Problems, configurations, and advantageous effects other than described above will be apparent from the following description of an embodiment.
In the following, an embodiment of the present invention will be described by way of the drawings.
A machine 1000 is a machine comprised in, e.g., railroad or construction equipment. Values of, e.g., engine pressure, cooling water temperature, and revolving speed are measured from sensors installed on respective parts of the machine and sent to an analysis device 1100. Internal parts of the analysis device 1100 are described below.
An input unit 1110 is comprised of a keyboard, a mouse, a touch panel, etc. and is a device that is used for inputting diagnostic parameters.
A display unit 1190 is comprised of a liquid crystal display or the like and is a device that displays screens illustrated in
A parameter management unit 1120 stores diagnostic parameters and information set for a criterion to narrow down and display data, as in
A data table structure 12050 in
A data table structure 12250 in the same figure stores a conditional expression 12400 for judging what operating mode 12300 in which the machine is now operating. A conditional expression is composed of an inequality or the like that can be calculated from the value of each sensor. When each conditional expression given in the column of conditional expression 12400 is fulfilled, it can be judged that the machine is operating in the operating mode 12300 associated with the conditional expression.
A data table structure 12450 in
A threshold value 12500 of a narrow down condition a) is a threshold value of a trend graph change amount for a period when a value in a trend graph changed greatly before and after parameter adjustment. If an abnormality degree change amount is beyond a value of the threshold value 12500 before and after parameter modification, a display is made as in
A threshold value 12600 of b) is a threshold value of an abnormality degree change rate=a ratio of “a change amount of abnormality degree/a change amount of a parameter” before and after parameter adjustment. This is a condition on a natural assumption that, when a parameter has been changed greatly (an amount of change is large), an abnormality degree trend graph also changes largely.
Only abnormality degree data for which this change rate is beyond a value of the threshold value 12600 of abnormality degree change rate is displayed, as in
A maintenance history storing unit 1130 in
A trend data storing unit 1140 in
A graph generating unit 1160 in
A display data filtering calculation unit 1170 in
A diagnosis unit 1180 in
Then, a process that is performed in the present embodiment is described with flowcharts. A main flow is illustrated in
At step 2000 (hereinafter labeled as S2000) in the main routine in
At S2010 and S2015, the process executes a diagnosis and calculates an abnormality degree by the method illustrated with
First, at S2010, the process makes clusters and learns data during normal operation. The process loads sensor data between the learning start time 3100 and the learning end time 3150 in
At S2015, the process calculates an abnormality degree that is a distance from the cluster center for each sensor value of sensor data for diagnosis. The process stores the calculated abnormality degree into a column of abnormality degree (previous abnormality degree) 14500, which is an abnormality degree before modifying a diagnostic parameter, within the lower table 14350 in
At S2020, the process displays a graph of abnormality degree data thus calculated as in
False alert: the abnormality degree is above or at the abnormality degree threshold value 12700, whereas no abnormality occurs according to the maintenance history.
Missing alert: the abnormality degree is less than the abnormality degree threshold value 12700, whereas an abnormality occurs according to the maintenance history.
A period when an abnormality degree exceeds the abnormality degree threshold value does not correspond with the period recorded as an abnormal period in the maintenance history; such period is a period for which a false or missing alert should be displayed. The process displays the result as in
To eliminate this false or missing alert, pressing the Modify Parameter button 4250 by the user makes the process proceed to a next step S2030.
At S2030, the process displays a screen for re-inputting diagnostic parameters, while comparing it with the diagnostic parameters which were input at S2000, as in
At S2040, the process reexecutes the processing operations performed at S2050 and S2020, using a diagnostic parameter that was re-input on the screen 5000 in
At S2050, the process displays stored abnormality degree data in separate graphs for comparison: a graph 6000 after parameter modification and a graph 6400 before the modification, as in
At S2060, the process displays a setting screen for specifying narrow down conditions to display abnormality degree data, as in
In
Additionally, for a narrow down condition 7500, an operating mode of a machine for which abnormality degree data is displayed can be selected from a list of operating modes. This list of operating modes is data loaded from the column of operating mode 12300 in
S2065 is an operation to check the following: it has been verified whether one or more narrow down conditions to display abnormality degree apply with respect to abnormality degree points of all time instants. If such check is complete with respect to abnormality degree points of all time instants, the process terminates the present main routine. If not so, the process proceeds to S2070.
S2070 calls a subroutine SUB01 that judges whether or not to permit displaying data and returns a result so that the process will judge whether displaying abnormality degree data at a time instant, now under check, is permitted. This step calls SUB01 with an argument of an abnormality degree at the oldest time instant. A process within SUB01 will be described later.
S2075 makes the process return to S2065, if no permission to display data has been returned in S2070, and the process judges whether or not to permit displaying next abnormality degree data. If permission to display data has been returned, the process proceeds to S2080.
At S2080, the process plots an abnormality degree point for which displaying data was permitted. By repeating S2070 through S2080, it is possible to display an abnormality degree graph in which only periods to be noted by the analysis operator are emphasized and displayed, as in
In the following, SUB01 in
If a condition by abnormality degree difference is enabled at S9150, the process proceeds to S9200. If an absolute value of “a value in the column of abnormality degree 14600—a value in the column of abnormality degree 14500” at the same time instant in
If a narrow down condition 7200 for display by abnormality degree change rate is enabled at S9250, the process proceeds to S9300.
At S9300, the process calculates an abnormality degree change rate=“a change amount of abnormality degree/a change amount of a parameter” and, if the calculated rate is larger than the threshold value of abnormality degree change rate 12600 in
At S9350, if the narrow down condition 7300 for display in
S9400 calls a subroutine SUB02 and judges whether the larger/smaller relation between the abnormality degree and the threshold value has changed before and after parameter modification. A process within SUB02 will be described later.
At 9450, if the larger/smaller relation between the abnormality degree and the threshold value has changed from the result of judgment in S9350, the process permits displaying data and proceeds to S9500.
At 9500, the process judges whether a narrow down condition 7400 in
At S9550, it is judged whether a hidden loopback parameter exists by a subroutine SUB03.
A process within SUB03 will be described later.
At S9600, if a hidden loopback parameter exists, as judged by SUB03, the process permits displaying data and then proceeds to S9650.
At S9650, the process judges whether a narrow down condition 7500 for display by operating mode in
At S9700, the process judges whether an operating mode checked under the narrow down condition 7500 is true by referring to sensor data at the same time instant as a time instant 14440 of abnormality degree and from sensor data in terms of engine pressure 14100 (
At S9750, the process has permitted displaying data in terms of all conditions for display and, therefore, issues a permission to display data to the main routine and terminates SUB01.
Then, the process within SUB02 that is called from S9400 is described with
A) A condition for a judgment that the larger/smaller relation does not change satisfies A-1) or A-2) below:
If A-1) or A-2) is true, the process returns a message that the larger/smaller relation of the abnormality degree against threshold value has changed to SUB01 at S10400.
If B-1) or B-2) is true, the process returns a message that the larger/smaller relation does not change to SUB01 at S10500.
Then, the process within SUB03 that is called from S9550 is described. SUB03 is a flow for judging whether a hidden loopback parameter which can further reduce the occurrence of false and missing alerts hides between the original and modified values of a diagnostic parameter. If a hidden loopback parameter hides, SUB03 returns permission to display abnormality degree data to SUB01. A hidden loopback parameter is explained with
In
In
The judgment method is as follows: move a diagnostic parameter value p_now in
SUB03 is a flow for judging whether this hidden loopback parameter exists between values set for the previous set value 12100 and the current set value 12200 in
Then, a description is provided about SUB03 with
S11100 in
S11300 through S1140 initialize variables A_before, A_now, and A_after representing an abnormality degree.
As illustrated in the flow, an initial value thus set is an abnormality degree for each variable calculated using each value of the variables p_before, p_now, and p_after of a diagnostic parameter (the number of clusters).
At S11450, while shifting p_now by Δp, the process checks to see whether a condition to terminate the operation of judging whether p_now is a hidden loopback parameter is satisfied. If P_after is not beyond a value set for the current set value 12200 in
At S11500, the process checks whether there is a match of the positive and negative signs of abnormality degree differences described with
S11550 is an operation of adding Δp to each of p_before, p_now, and p_after to make a judgment for a next value of the diagnostic parameter.
S11600 and S11650 are an operation of updating abnormality degree values A_before and A_now to respond with adding Δp to the diagnostic parameter values.
S11700 executes a diagnosis using p_after, calculates an abnormality degree, and assigns a result to A_after in order to update A_after. After that, the process returns to S11450 and process to a next judgment operation.
A series of the processes of the embodiment of the present invention is now complete.
Number | Date | Country | Kind |
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2014-160938 | Aug 2014 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2015/057622 | 10/6/2015 | WO | 00 |