Lubricant abnormality detection system, lubricant abnormality detection device, lubricant abnormality detection method, lubricant abnormality detection program, and recording medium

Abstract

To provide a new technique for determining an abnormal state of lubricating oil.SOLUTION: A lubricant abnormality detection system (1) includes an electrical characteristic acquisition unit (111) that acquires an electrical characteristic of a lubricant, a minimum value determination unit (114) that determines a minimum value of the lubricant, and an abnormal state determination unit (150) that determines an abnormal state of the lubricant on the basis of the electrical characteristic and a determination result of the minimum value by the minimum value determination unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lubricant oil abnormality detection system, a lubricant oil abnormality detection device, a lubricant oil abnormality detection method, a lubricant oil abnormality detection program, and a recording medium. [Background technology]

[0002] Patent Document 1 describes a method for predicting failures in equipment that uses lubricating oil. Patent Document 2 describes a method for diagnosing the degree of deterioration of lubricating oil based on color information. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-167791 [Patent Document 2] Japanese Patent Application Publication No. 2020-012690 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to provide a new technique for determining an abnormal state of lubricating oil. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, a lubricant abnormality detection system according to one embodiment of the present invention comprises an electrical characteristic acquisition unit that acquires electrical characteristic information indicating the electrical characteristics of the lubricant, a minimum value determination unit that determines the minimum value at which the electrical characteristics of the lubricant decrease with use and then begin to increase, and an abnormal state determination unit that determines an abnormal state of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit and the minimum value determination result by the minimum value determination unit.

[0006] In order to solve the above-mentioned problems, a lubricant abnormality detection device according to one embodiment of the present invention comprises an electrical characteristic acquisition unit that acquires electrical characteristic information indicating the electrical characteristics of the lubricant, a minimum value determination unit that determines the minimum value at which the electrical characteristics of the lubricant decrease with use and then begin to increase, and an abnormal state determination unit that determines an abnormal state of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit and the minimum value determination result by the minimum value determination unit.

[0007] In order to solve the above-mentioned problems, a lubricant abnormality detection method according to one embodiment of the present invention is a lubricant abnormality detection method executed by one or more computers, and includes an electrical characteristic acquisition step of acquiring electrical characteristic information indicating the electrical characteristics of the lubricant, a minimum value determination step of determining a minimum value, which is the minimum value when the electrical characteristics of the lubricant decrease with use and then begin to increase, and an abnormal state determination step of determining an abnormal state of the lubricant based on the electrical characteristic information acquired in the electrical characteristic acquisition step and the determination result of the minimum value in the minimum value determination step.

[0008] A lubricant oil abnormality detection device according to one embodiment of the present invention may be realized by a computer. In this case, the lubricant oil abnormality detection program that causes the computer to operate as each part (software element) of the lubricant oil abnormality detection device, and the computer-readable recording medium on which the program is recorded, also fall within the scope of the present invention. [Effects of the Invention]

[0009] According to one aspect of the present invention, a new technique for determining an abnormal state of lubricating oil can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram showing an example of the configuration of a lubricant oil abnormality detection system according to an embodiment of the present invention. [Figure 2] 1 is a flowchart showing the flow of a lubricant oil abnormality detection method according to an embodiment of the present invention. [Figure 3] 1 is a graph showing the capacitance ratio at 30° C. versus the deterioration time in the ISOT test for gas engine oil A containing a calcium detergent and having a calcium content of 0.29 wt %. [Figure 4] 1 is a graph showing the capacitance ratio at 30° C. versus the ISOT test deterioration time for gas engine oil B containing a calcium detergent and having a calcium content of 0.10 wt %. [Figure 5] 1 is a graph showing the capacitance ratio at 30° C. versus the deterioration time in the ISOT test for engine oils containing no metal-based detergents. DETAILED DESCRIPTION OF THE INVENTION

[0011] As shown in the Reference Examples below, the inventors conducted a detailed analysis of the electrical properties of lubricating oils over time. They discovered that, depending on the type of lubricating oil containing a metal-based detergent, the electrical properties decrease with use and then begin to increase. This minimum value is the lowest value at which the electrical properties decrease and then increase. The electrical properties depend on the type and amount of polar substances. A decrease in the amount of polar substances decreases the electrical properties, while an increase in the amount of polar substances increases the electrical properties. Because metal-based detergents are polar substances, their consumption and decrease in amount is thought to decrease the electrical properties. On the other hand, many of the degradation products of the main oil and additives other than the metal-based detergent are polar substances. Therefore, the electrical properties increase as the main oil and additives other than the metal-based detergent deteriorate. The inventors focused on these points and completed the present invention. The lubricating oil abnormality detection system according to one aspect of the present invention is a new technology that takes the minimum value into account to determine an abnormal state of a lubricating oil.

[0012] [Embodiment] The configuration of the lubricant oil abnormality detection system 1 according to this embodiment will be described in detail below.

[0013] <Configuration of Lubricant Abnormality Detection System 1> FIG. 1 is a block diagram schematically illustrating an example of the configuration of a lubricant abnormality detection system 1 according to this embodiment.

[0014] The lubricant abnormality detection system 1 according to this embodiment includes a lubricant abnormality detection device 10, an electrical property sensor 20, a temperature sensor 30, and a property sensor 40. The lubricant abnormality detection device 10 acquires values ​​measured by each sensor, determines whether the lubricant is in an abnormal state, and displays the abnormal state determination result. The lubricant abnormality detection device 10 may be implemented, for example, as a portable computer terminal or a stationary computer terminal. In the case of a portable computer terminal, the user can check the abnormal state determination result displayed on the lubricant abnormality detection device 10 at any time. The electrical property sensor 20, temperature sensor 30, and property sensor 40 may be permanently installed in a container, such as a tank, that stores the lubricant in a machine that uses the lubricant, or may be brought into contact with the lubricant as needed. In the case of permanent installation in the container, the electrical properties, temperature, and properties of the lubricant in the container can be constantly and continuously measured.

[0015] (Lubricant Abnormality Detection Device 10) The lubricant abnormality detection device 10 includes a control unit 100, a storage unit 200, and a display unit 300. The control unit 100, the storage unit 200, the display unit 300, and a communication interface (not shown), which will be described later, are connected via a bus. In this embodiment, the control unit 100 and the storage unit 200 are included in the lubricant abnormality detection device 10, but this configuration is not limited thereto. They may also be included in an external server separate from the lubricant abnormality detection device 10. In this case, the lubricant abnormality detection device 10 displays the results determined by the external server. The communication interface is an interface for connecting to a network. The communication interface may be, for example, a wired connection interface such as Ethernet (registered trademark) or a wireless connection interface such as WiFi (registered trademark), or may be a wired connection interface. For example, the communication interface connects the electrical characteristic acquisition unit 111 to the electrical characteristic sensor 20 so that the electrical characteristic acquisition unit 111 acquires electrical characteristic information from the electrical characteristic sensor 20. The communication interface also connects the temperature acquisition unit 121 and the temperature sensor 30 so that the temperature acquisition unit 121 acquires temperature information from the temperature sensor 30. The communication interface also connects the property acquisition unit 131 and the property sensor 40 so that the property acquisition unit 131 acquires property information from the property sensor 40. Furthermore, the communication interface may connect the abnormal state determination unit 150 and an external server so that the abnormal state determination unit 150 outputs the abnormal state determination result to an external server separate from the lubricant abnormality detection device 10.

[0016] (Control unit 100) The control unit 100 controls each part of the lubricant abnormality detection device 10 by executing a program stored in the storage unit 200. The processor is configured by an integrated circuit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), for example.

[0017] Next, a description will be given of the functional configuration of the control unit 100. The control unit 100 includes an electrical property unit 110, a temperature unit 120, a property unit 130, a moving average value calculation unit 140, an abnormal state determination unit 150, and a display control unit 160.

[0018] (Electrical Properties Unit 110) The electrical characteristic unit 110 is a unit that performs processing related to electrical characteristics and includes an electrical characteristic acquisition unit 111, an electrical characteristic temperature correction determination unit 112, an electrical characteristic temperature correction unit 113, a minimum value determination unit 114, and an electrical characteristic comparison unit 115.

[0019] The electrical characteristic acquisition unit 111 acquires electrical characteristic information indicating the electrical characteristics of the lubricant from the electrical characteristic sensor 20. Examples of the electrical characteristics include capacitance, electrical conductivity, and dielectric constant.

[0020] The electrical characteristic acquisition unit 111 acquires electrical characteristic information output from the electrical characteristic sensor 20 via the communication interface. The electrical characteristic acquisition unit 111 outputs the acquired electrical characteristic information to the electrical characteristic temperature correction determination unit 112 and the storage unit 200. The electrical characteristic information is information indicating the results of measurement of the electrical characteristics of the lubricating oil by the electrical characteristic sensor 20. The electrical characteristic sensor 20 will be described later.

[0021] The electrical characteristic temperature correction determination unit 112 determines whether or not temperature correction is required for the electrical characteristic information based on the temperature information acquired by the temperature acquisition unit 121 and the electrical characteristic information acquired by the electrical characteristic acquisition unit 111.

[0022] For example, the electrical characteristic temperature correction determination unit 112 compares the temperature information acquired by the temperature acquisition unit 121 with a preset temperature range for which temperature correction of the electrical characteristic information is not required. If the temperature information acquired by the temperature acquisition unit 121 falls within the range, the electrical characteristic temperature correction determination unit 112 determines that temperature correction is not required for the electrical characteristic information. On the other hand, if the temperature information acquired by the temperature acquisition unit 121 does not fall within the range, the electrical characteristic temperature correction determination unit 112 determines that temperature correction is required for the electrical characteristic information.

[0023] If the electrical characteristic temperature correction determination unit 112 determines that temperature correction is not required for the electrical characteristic information, it outputs the electrical characteristic information to the minimum value determination unit 114 and the storage unit 200. If the electrical characteristic temperature correction determination unit 112 determines that temperature correction is required for the electrical characteristic information, it outputs the determination result as to whether temperature correction of the electrical characteristic information is required to the electrical characteristic temperature correction unit 113 and the storage unit 200.

[0024] When the electrical characteristic temperature correction determination unit 112 determines that temperature correction is required for the electrical characteristic information, the electrical characteristic temperature correction unit 113 performs temperature correction on the electrical characteristic information. For example, the electrical characteristic temperature correction unit 113 stores temperature information and electrical characteristic information for the type of lubricant to be determined in advance as a database, and calculates a correction formula (relational formula) based on the database. The electrical characteristic temperature correction unit 113 performs temperature correction on the electrical characteristic information by referring to the calculated correction formula. Because electrical characteristics are affected by temperature, the electrical characteristic temperature correction unit 113 performs temperature correction, allowing the abnormal state determination unit 150 to more accurately determine whether the lubricant is in an abnormal state.

[0025] The electrical characteristic temperature corrector 113 outputs the electrical characteristic information after temperature correction to the minimum value determiner 114 and the storage unit 200 .

[0026] In the present embodiment, as described above, the electrical characteristic unit 110 includes the electrical characteristic temperature correction determination unit 112 and the electrical characteristic temperature correction unit 113 and performs temperature correction of the electrical characteristic information. However, the present invention is not limited to this configuration. The electrical characteristic unit 110 does not necessarily have to include the electrical characteristic temperature correction determination unit 112 and the electrical characteristic temperature correction unit 113. That is, in the present invention, temperature correction of the electrical characteristic information may or may not be performed, and the determination of whether temperature correction is necessary may or may not be performed. If the electrical characteristic unit 110 does not perform temperature correction of the electrical characteristic information, it is preferable to provide a temperature regulator (not shown) that controls the temperature of the lubricating oil near the electrodes of the electrical characteristic sensor 20. The temperature regulator may be a housing having a space for storing the electrodes of the electrical characteristic sensor 20. The space for storing the electrodes of the electrical characteristic sensor 20 in the housing at least stores the detection unit of the temperature sensor 30 and a temperature change device (e.g., a heater) that changes the temperature. By pouring lubricant into a space that houses the electrodes of the housing, the detection unit of the temperature sensor 30, and the temperature change device, the temperature of the lubricant that has entered the space is detected based on the value of the temperature sensor 30. Next, it is confirmed whether the temperature of the lubricant that has entered the space is an appropriate value for acquiring electrical characteristic information. If necessary, the temperature of the housing is changed by the temperature change device. The temperature change by the temperature change device may be performed by the control unit 100, or the user of the lubricant abnormality detection system may change the temperature based on the value of the temperature sensor 30 via a controller or the like for controlling the temperature.

[0027] The minimum value determination unit 114 determines the minimum value of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit 111 or the temperature-corrected electrical characteristic information corrected by the electrical characteristic temperature correction unit 113. The minimum value is the smallest value at which the electrical characteristic decreases as the lubricant is used and then begins to increase. Specifically, the minimum value determination unit 114 (1) determines whether the lubricant being determined is a lubricant having a minimum value, and (2) if it is determined in (1) that the lubricant being determined is a lubricant having a minimum value, it determines the relationship between the current value and the minimum value.

[0028] First, in (1), an example of a specific method in which the minimum value determination unit 114 determines whether the lubricant to be determined is a lubricant having a minimum value will be described below.

[0029] As an example, the minimum value determination unit 114 determines whether the lubricant being determined has a minimum value by referring to the change over time in the electrical characteristic information stored in the storage unit 200. If the electrical characteristic information is on a downward trend from the initial value, the minimum value determination unit 114 determines that the lubricant has a minimum value. If the electrical characteristic information is on an upward trend from the initial value, the minimum value determination unit 114 determines that the lubricant does not have a minimum value.

[0030] As another example, the minimum value determination unit 114 determines whether the lubricant to be determined has a minimum value by referring to a database stored in advance in the storage unit 200. For example, the database contains information on whether each type of lubricant has a minimum value (hereinafter also referred to as minimum value information). A user inputs the type of lubricant to be determined via an input unit (not shown) of the lubricant abnormality detection device 10. The minimum value determination unit 114 determines whether the minimum value information for the input lubricant type is included in the database. If the minimum value determination unit 114 determines that the minimum value information for the input lubricant type is included in the database, it determines whether the lubricant to be determined has a minimum value based on the minimum value information. If the minimum value determination unit 114 determines that the minimum value information for the input lubricant type is not included in the database, it may perform re-determination by, for example, referring to the change over time in the electrical characteristic information described above.

[0031] Next, if the minimum value determination unit 114 determines in (1) that the lubricant being determined has a minimum value, it determines the relationship between the current value and the minimum value in (2). It is preferable that the minimum value determination unit 114 always determines the relationship between the current value and the minimum value. For example, it is preferable to continue determining the minimum value even after once determining that a past value is a minimum value or even after determining that the current value has already reached a minimum value. For example, even if the electrical characteristic has decreased and then started to increase, it may decrease again and then start to increase again. In this case, the minimum value determination unit 114 may determine that both minimum values ​​at each point in time when the electrical characteristic changes from decrease to increase are minimum values. For example, if an abnormal condition occurs in which fuel is mixed into a lubricant containing a metal-based detergent, the electrical characteristic may start to increase due to the fuel mixing, even though the electrical characteristic, which had decreased due to the influence of the metal-based detergent, has not yet reached the minimum value inherent in the properties of the lubricant. Similarly, the electrical characteristics may also increase due to the inclusion of metal (wear debris) and water. In these cases, the minimum value determination unit 114 may first determine the minimum value when the electrical characteristics change from decreasing to increasing as a minimum value, and may also determine the minimum value when the electrical characteristics change from decreasing to increasing due to the presence of a metal-based cleaning agent as a minimum value. In this way, it is preferable for the minimum value determination unit 114 to continuously determine the minimum values, from the viewpoint of preventing the overlooking of a minimum value due to a metal-based cleaning agent, even when multiple minimum values ​​occur.

[0032] In (2), an example of a specific method by which the minimum value determination unit 114 determines whether a past value is a minimum value will be described below. That is, whether the electrical characteristic has reached a minimum value can be determined by, for example, comparing the current value with the past value. Therefore, the minimum value determination unit 114 determines whether a past value (e.g., a measurement value in the immediately preceding measurement) prior to measuring the current value was a minimum value.

[0033] As an example, the minimum value determination unit 114 first calculates the difference between the current value and the previous value of the electrical characteristic. Here, the "current value" refers to the measurement value obtained in the current measurement as the target for determining whether an abnormal state is present. The "past value" refers to the measurement value obtained in the measurement immediately preceding the current measurement. Next, the minimum value determination unit 114 compares the current difference with the previous difference and determines whether the previous value is a minimum value based on whether there is a sign reversal (positive or negative). The "current difference" refers to the difference between the current value and the previous value, and the "previous difference" refers to the difference between the measurement value obtained in the measurement immediately preceding the current measurement and the measurement obtained two measurements prior to the current measurement. If there is a sign reversal between the current difference and the previous difference, the minimum value determination unit 114 determines that the past value is a minimum value. If there is no sign reversal between the current difference and the previous difference, the minimum value determination unit 114 determines that the past value is not a minimum value. Specifically, a case where the measured value changes from (1) 100 to (2) 90 to (3) 95 will be described as an example. In this case, the difference between (1) and (2) is -10 (negative), and the difference between (2) and (3) is 5 (positive). The minimum value determination unit 114 determines that (2) is the minimum value because the sign of the difference between (1) and (2) and the sign of the difference between (2) and (3) are reversed.

[0034] Alternatively, the minimum value determination unit 114 may compare the current difference with a preset difference threshold, rather than comparing the current difference with the previous difference. As an example, the minimum value determination unit 114 compares the current value with a past value, and determines whether the calculated current difference is equal to or greater than a preset difference threshold. If the calculated current difference is equal to or greater than the preset difference threshold, the minimum value determination unit 114 determines that the past value is a minimum value. If the calculated current difference is less than the preset difference threshold, the minimum value determination unit 114 determines that the past value is not a minimum value. Specifically, a case will be described where the preset difference threshold is 0 and the measurement value changes from (1) 100 to (2) 90 to (3) 95. In this case, the difference between (1) and (2) is -10, and the difference between (2) and (3) is 5. The minimum value determination unit 114 determines that (2) is the minimum value because the difference between (2) and (3) is equal to or greater than a preset difference threshold. The specific numerical value of the preset difference threshold described above is merely an example, and the preset difference threshold can be set as appropriate. Note that in this embodiment, the preset difference threshold is set to 0, but the threshold may be set taking error into consideration.

[0035] Although an example of determining whether a past value is a minimum value has been described here, the minimum value determination unit 114 may determine that there is a minimum value between the past value and the current value if the current difference is zero. Specifically, a case will be described as an example in which the measurement value changes from (1) 100 to (2) 90 to (3) 90 to (4) 100. In this case, the difference between (1) and (2) is -10, the difference between (2) and (3) is 0, and the difference between (3) and (4) is 10. Since the difference between (2) and (3) is 0, the minimum value determination unit 114 determines that there is a minimum value between (2) and (3). In this way, even if the current difference is zero, by making the determination as described above, it is possible to prevent the minimum value from being overlooked.

[0036] As yet another example, the minimum value determination unit 114 may make a determination using a trained model obtained by machine learning using the components, electrical property information, temperature information, property information, etc., and the presence or absence, value, etc. of minimum values ​​of the electrical properties as training data. The specific configuration of the learning process for obtaining the determination result of the minimum value is not particularly limited, and machine learning techniques such as a support vector machine, linear regression, random forest, a neural network and a group of gradient boosting trees, a genetic algorithm, a gradient descent method, and Bayesian optimization can be used, for example.

[0037] As another example, the current value of the electrical characteristic may be compared with a minimum threshold value that is preset for each type of lubricant to determine the minimum value of the electrical characteristic. If the current value of the electrical characteristic is equal to or less than the threshold value, the minimum value determination unit 114 determines that the current value is a minimum value. If the current value of the electrical characteristic is greater than the threshold value, the minimum value determination unit 114 determines that the current value is not a minimum value.

[0038] Furthermore, if the minimum value determination unit 114 determines that the past value or the current value is not a minimum value, i.e., if the lubricant has a minimum value but the past value or the current value is not a minimum value, the minimum value determination unit 114 may further determine the relationship between the past value or the current value and the minimum value. For example, the minimum value may be determined by using the rate of change from a measurement value prior to the past value to the past value or the rate of change from a past value to the current value, or by calculating an estimated minimum value. Furthermore, if a minimum value (or its estimated value) based on the type of lubricant is stored in advance in the storage unit 200, the difference from the minimum value may be determined. Furthermore, the minimum value determination unit 114 may determine whether the time when the minimum value will be reached has already passed based on the rate of change from a measurement value prior to the past value to the past value or the rate of change from a past value to the current value.

[0039] The minimum value determination unit 114 outputs the determination result of the minimum value to the electrical characteristic comparison unit 115, the moving average value calculation unit 140, the abnormal state determination unit 150, and the storage unit 200.

[0040] The electrical characteristic comparing unit 115 compares the current value of the electrical characteristic with a past value. The current value of the electrical characteristic may be a value acquired by the electrical characteristic acquiring unit 111, a value corrected by the electrical characteristic temperature correcting unit 113, or a moving average value of the electrical characteristic information calculated by the moving average value calculating unit 140. The electrical characteristic comparing unit 115 may also correct the electrical characteristic information according to the determination result of the minimum value determining unit 114 to obtain the current value. The electrical characteristic comparing unit 115 acquires past values ​​of the electrical characteristic from the storage unit 200.

[0041] Furthermore, for example, the electrical characteristic comparing unit 115 subtracts a past value of the electrical characteristic from a current value thereof and determines whether the calculated value is positive or negative. Furthermore, for example, the electrical characteristic comparing unit 115 calculates a difference between a current value and a past value of the electrical characteristic described above and compares the calculated difference with a preset difference threshold. Furthermore, for example, the electrical characteristic comparing unit 115 determines whether the calculated difference is equal to or greater than a preset difference threshold.

[0042] The electrical characteristic comparison unit 115 outputs the comparison result of the electrical characteristic information to the abnormal state determination unit 150 and the storage unit 200.

[0043] In this embodiment, as described below, a configuration is described in which the determination of the electrical characteristics reaching a minimum value is used as a trigger for determining deterioration and soot contamination after that point, but the present invention is not limited to this configuration. For example, depending on the determination result of the minimum value determination unit 114, the electrical characteristic comparison unit 115 may use the determination result to correct the electrical characteristic information and set the corrected value as a past value or a present value. For example, if it is known that the lubricant being measured is a specific lubricant containing a metal-based detergent, the electrical characteristic information can be corrected as follows. In this case, for example, the correction may be based on the difference between the behavior of the electrical characteristics when no abnormalities occur in a specific lubricant containing a metal-based detergent and the behavior of the electrical characteristics when no abnormalities occur in the specific lubricant without a metal-based detergent.

[0044] (Temperature unit 120) The temperature unit 120 is a unit that performs processing related to temperature. The temperature unit 120 includes a temperature acquisition unit 121.

[0045] The temperature acquisition unit 121 acquires temperature information indicating the temperature of the lubricating oil from the temperature sensor 30. The temperature acquisition unit 121 may acquire the temperature information output from the temperature sensor 30 via a communication interface. The temperature acquisition unit 121 outputs the acquired temperature information to the moving average value calculation unit 140, the abnormal state determination unit 150, and the storage unit 200. The temperature information is information indicating the results of measuring the temperature of the lubricating oil by the temperature sensor 30. The temperature sensor 30 will be described later.

[0046] The current temperature value may be a value acquired by the temperature acquisition unit 121, or may be a moving average value of temperature information calculated by the moving average value calculation unit 140, which will be described later.

[0047] (Property Unit 130) The property unit 130 includes a property acquisition section 131, a property temperature correction determination section 132, a property temperature correction section 133, and a property comparison section 134.

[0048] The property acquisition unit 131 acquires property information indicating the properties of the lubricating oil from the property sensor 40. In this specification, "property" refers to properties other than electrical properties and temperature. Examples of properties include viscosity, density, acid number, base number, and color tone. In one embodiment of the present invention, one or more of these properties may be measured. The property acquisition unit 131 may acquire the property information output from the property sensor 40 via a communication interface. The property acquisition unit 131 outputs the acquired property information to the property temperature correction determination unit 132 and the memory unit 200. The property information is information indicating the results of measurement of the properties of the lubricating oil by the property sensor 40. The property sensor 40 will be described later.

[0049] The property temperature correction determining unit 132 determines, based on the temperature information acquired by the temperature acquiring unit 121 and the property information acquired by the property acquiring unit 131, whether or not temperature correction is required for the property information.

[0050] For example, the property temperature correction determination unit 132 compares the temperature information acquired by the temperature acquisition unit 121 with a preset temperature range in which temperature correction of property information is not required. If the temperature information acquired by the temperature acquisition unit 121 is included in this range, the property temperature correction determination unit 132 determines that temperature correction is not required for the property information. On the other hand, if the temperature information acquired by the temperature acquisition unit 121 is not included in this range, the property temperature correction determination unit 132 determines that temperature correction is required for the property information.

[0051] If the property temperature correction determination unit 132 determines that the property information does not require temperature correction, it outputs the property information to the property comparison unit 134 and the storage unit 200. If the property temperature correction determination unit 132 determines that the property information requires temperature correction, it outputs the determination result as to whether or not temperature correction of the property information is required to the property temperature correction unit 133 and the storage unit 200.

[0052] When the property temperature correction determination unit 132 determines that temperature correction is required for the property information, the property temperature correction unit 133 performs temperature correction of the property information. For example, the property temperature correction unit 133 stores temperature information and viscosity information of the type of lubricant to be determined in advance as a database and calculates a correction formula based on the database. The property temperature correction unit 133 performs temperature correction of the property by referring to the calculated correction formula. Since properties are affected by temperature, the property temperature correction unit 133 performs temperature correction, allowing the abnormal state determination unit 150 to more accurately determine an abnormal state of the lubricant.

[0053] The property temperature correcting unit 133 outputs the property information after the temperature correction to the property comparing unit 134 and the storage unit 200 .

[0054] The property comparison unit 134 compares the current property value with a past property value. The current property value may be a value acquired by the property acquisition unit 131, a value corrected by the property temperature correction unit 133, or a moving average value of property information calculated by the moving average value calculation unit 140 (described later). The property comparison unit 134 also acquires past property values ​​from the storage unit 200. As one example, the property comparison unit 134 calculates the difference between the current property value and the past property value, and compares the calculated difference with a preset difference threshold. The property comparison unit 134 determines whether the calculated difference is equal to or greater than the preset difference threshold. As another example, the property comparison unit 134 subtracts the past property value from the current property value, and determines whether the calculated value is positive.

[0055] The property comparison unit 134 outputs the comparison result of the property information to the abnormal state determination unit 150 and the storage unit 200.

[0056] (Moving average value calculation unit 140) When the moving average value is used as the current value in the electrical characteristic comparison unit 115, the abnormal state determination unit 150, and the property comparison unit 134, the moving average value calculation unit 140 calculates the moving average value based on multiple values ​​per unit time of the electrical characteristic information, temperature information, and property information.

[0057] The moving average value calculation unit 140 outputs the calculated moving average value to the electrical characteristic comparison unit 115 , the abnormal state determination unit 150 , the property comparison unit 134 , and the storage unit 200 .

[0058] (Abnormal state determination unit 150) The abnormal state determination unit 150 determines an abnormal state of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit 111 and the minimum value determination result by the minimum value determination unit 114. Specifically, the abnormal state determination unit 150 determines an abnormal state of the lubricant based on the minimum value determination result determined by the minimum value determination unit 114 and the comparison result by the electrical characteristic comparison unit 115. By using the minimum value determination result to determine an abnormal state, when the lubricant to be determined contains a metal-based detergent, the abnormal state determination unit 150 can eliminate factors that cause extreme polarity changes resulting from consumption of the metal-based detergent, thereby enabling the abnormal state to be determined with high accuracy.

[0059] For example, the abnormal state determination unit 150 can determine an abnormal state of the lubricant by comparing the electrical characteristic information obtained by the electrical characteristic comparison unit 115 with a preset abnormal electrical characteristic value. Also, for example, the abnormal state determination unit 150 can more accurately detect an increase in the electrical characteristic by using the current value of the electrical characteristic corrected in accordance with the determination result of the minimum value in the electrical characteristic comparison unit 115, and therefore can more accurately determine an abnormal state.

[0060] Furthermore, the abnormal condition determination unit 150 may determine an abnormal condition further based on the temperature information obtained by the temperature acquisition unit 121 and the property information obtained by the property acquisition unit 131. Specifically, the abnormal condition determination unit 150 determines an abnormal condition of the lubricant based on the minimum value determination result obtained by the minimum value determination unit 114, the comparison result obtained by the electrical property comparison unit 115, the temperature information obtained by the temperature acquisition unit 121, and the comparison result obtained by the property comparison unit 134. By determining an abnormal condition by further referring to the temperature information and the property information, it is possible to more accurately determine an abnormal condition.

[0061] When the determination of an abnormal state may be affected by the electrical characteristics, it is preferable that the abnormal state determination unit 150 determine the abnormal state after referring to the determination result of the minimum value. In this case, for example, the abnormal state determination unit 150 determines the abnormal state after the electrical characteristics reach the minimum value. In other words, in determining an abnormal state that may be affected by the electrical characteristics, the determination result of the minimum value is used as a trigger for the abnormal state determination unit 150 to start determining the abnormal state. By referring to the determination result of the minimum value in this manner, it is possible to more accurately determine an abnormal state that may affect the electrical characteristics. Note that, when determining an abnormal state that is not an abnormal state that may be affected by the electrical characteristics, the abnormal state determination unit 150 may continue to determine the abnormal state regardless of the determination result of the minimum value. In other words, in this case, the abnormal state may be determined even before the electrical characteristics reach the minimum value.

[0062] The abnormal state is, for example, at least one selected from deterioration, fuel contamination, soot contamination, metal contamination, and water contamination. Deterioration is, for example, deterioration due to at least one of oxidation and heat. In the case of deterioration, the capacitance tends to increase, the viscosity tends to increase, and the density tends to increase. In the case of fuel contamination, the capacitance tends to increase, the viscosity tends to decrease, and the density tends to decrease. In the case of soot contamination, the capacitance tends to decrease, the viscosity tends to increase, and the density tends to increase. In the case of metal (wear powder) contamination, the capacitance tends to increase, the viscosity tends to remain unchanged, and the density tends to remain unchanged. In the case of water contamination, the capacitance tends to increase significantly, the viscosity tends to remain unchanged, and the density tends to remain unchanged. The abnormal state determination unit 150 determines various abnormal states by referring to these trends.

[0063] Examples of the abnormal state that may be affected by the electrical characteristics include deterioration and soot contamination. When determining deterioration and soot contamination, the abnormal state determination unit 150 determines deterioration and soot contamination after the time point at which the electrical characteristics reach a minimum value by referring to the electrical characteristic information, temperature information, and property information from that time point onward. In other words, when determining abnormal states of deterioration and soot contamination, the abnormal state determination unit 150 does not determine deterioration and soot contamination until the electrical characteristics reach a minimum value. In other words, in determining deterioration and soot contamination, the determination result of the minimum value is used as a trigger for the abnormal state determination unit 150 to start determining deterioration and soot contamination. Note that when determining metal contamination, moisture contamination, etc., the abnormal state determination unit 150 determines metal contamination, moisture contamination, etc. even before the electrical characteristics reach a minimum value. As mentioned above, even if the minimum value is measured more than once as a result, the trigger may be the arrival of the first minimum value, and if it is determined that there is a second minimum value after the first minimum value, or that there is a high possibility of this, the trigger may not be the arrival of the first minimum value, but rather the arrival of the second or subsequent minimum value.

[0064] The abnormal condition determination unit 150 outputs the abnormal condition determination result to the display control unit 160. Furthermore, the abnormal condition determination unit 150 may output the abnormal condition determination result to an external server via a communication interface.

[0065] (Display control unit 160) The display control unit 160 controls the display unit 300 to display the abnormal state determination result on the display unit 300. The display control unit 160 outputs the abnormal state determination result determined by the abnormal state determination unit 150 to the display unit 300. When the abnormal state determination unit 150 determines deterioration and soot contamination, the display control unit 160 may cause the display unit 300 to display the current value of the electrical characteristic and a message indicating that the minimum value has not been reached before the electrical characteristic reaches the minimum value, or may not display information about the electrical characteristic until the electrical characteristic reaches the minimum value.

[0066] (Storage unit 200) The storage unit 200 stores programs executed by the control unit 100 and various data used by the control unit 100. The storage unit 200 is configured, for example, with a hard disk drive (HDD), a solid state drive (SSD), an EEPROM (registered trademark) (Electrically Erasable Programmable Read-Only Memory), a read-only memory (ROM), a random access memory (RAM), or a combination thereof. Note that part or all of the memory is not limited to being built into the lubricant abnormality detection device 10, but may be externally attached via an input / output interface (not shown) such as a universal serial bus (USB). Also, part or all of the storage unit 200 may be connected to the lubricant abnormality detection device 10 via a network as a device independent of the lubricant abnormality detection device 10.

[0067] The storage unit 200 stores various types of information. For example, the storage unit 200 stores information such as the electrical characteristic information acquired by the electrical characteristic acquisition unit 111, the temperature information acquired by the temperature acquisition unit 121, the property information acquired by the property acquisition unit 131, the temperature-corrected electrical characteristic information temperature-corrected by the electrical characteristic temperature correction unit 113, the property information temperature-corrected by the property temperature correction unit 133, the minimum value determination result determined by the minimum value determination unit 114, the comparison result by the electrical characteristic comparison unit 115, the comparison result by the property comparison unit 134, the moving average value calculated by the moving average value calculation unit 140, the abnormal state determination result determined by the abnormal state determination unit 150, and various preset threshold values.

[0068] (Display section 300) The display unit 300 is controlled by the display control unit 160. The display unit 300 displays the abnormal state determination result by the abnormal state determination unit 150 output from the display control unit 160.

[0069] By knowing the results of the abnormality determination, the user can suggest an oil suitable for the machine using the lubricating oil and predict abnormalities in the parts of the machine.

[0070] (Electrical property sensor 20) The electrical property sensor 20 is a sensor for measuring the electrical properties of the lubricant. For example, when measuring capacitance, the electrical property sensor 20 preferably includes an interdigital electrode. The interdigital electrode has a structure in which comb-shaped electrodes are interdigitated. This structure of the interdigital electrode allows for a short distance between the electrodes. This distance may be, for example, 20 μm. The material of the electrodes is preferably, for example, platinum. The use of interdigital electrodes increases the sensitivity of the electrical properties of the oil. This allows for real-time detection of the electrical properties. The electrical property sensor 20 generates electrical property information indicating the results of measuring the electrical properties of the lubricant based on the results, and transmits the information to the lubricant abnormality detection device 10. Note that, in this embodiment, the electrical property sensor 20 includes an interdigital electrode. However, the electrical property sensor 20 of the present invention is not limited to this structure, and various conventionally known sensors may be used depending on the electrical properties of the object to be measured.

[0071] (Temperature sensor 30) The temperature sensor 30 is a sensor for measuring the temperature of the lubricant. There are no particular limitations on the temperature sensor 30, as long as it can appropriately measure the temperature of the lubricant within a desired range. Based on the results of measuring the temperature of the lubricant, the temperature sensor 30 generates temperature information that indicates the results and transmits it to the lubricant abnormality detection device 10.

[0072] (Property sensor 40) The property sensor 40 is a sensor for measuring the properties of the lubricant. There are no particular limitations on the property sensor 40, as long as it is a sensor that can appropriately measure the desired range of properties of the lubricant. Based on the results of measuring the properties of the lubricant, the property sensor 40 generates property information that indicates the results and transmits the information to the lubricant abnormality detection device 10.

[0073] (Type of lubricant) The type of lubricant for which the lubricant abnormality detection system 1 according to the present embodiment determines whether or not an abnormality exists is not particularly limited, and examples include internal combustion engine oil, drive system oil, and equipment oil. Specific examples of lubricant include gas engine oil, gasoline engine oil, and diesel engine oil. Lubricants may or may not contain metal-based detergents. However, the lubricant abnormality detection system 1 according to the present embodiment can be effectively used to determine whether or not an abnormality exists in lubricants containing metal-based detergents. The lubricant abnormality detection system 1 according to the present embodiment can accurately determine whether or not an abnormality exists in lubricants containing metal-based detergents because it determines the abnormality of the lubricant by taking into account the minimum value of the electrical properties, even for lubricants containing metal-based detergents. Metal-based detergents are used not only in internal combustion engine oils but also in various drive system oils and various equipment oils. Therefore, the lubricant abnormality detection system 1 according to the present embodiment can be used to determine the abnormality of various lubricants.

[0074] Examples of metal detergents include calcium detergents, magnesium detergents, and sodium detergents.

[0075] <Flow of lubricant abnormality detection method> The lubricant abnormality detection system 1 executes a lubricant abnormality detection method. Fig. 2 is a flow chart showing the flow of the lubricant abnormality detection method. As shown in Fig. 2, the lubricant abnormality detection method includes steps S101 to S110.

[0076] In step S101, the electrical characteristic acquisition unit 111 acquires electrical characteristic information from the electrical characteristic sensor 20. Also in step S101, the temperature acquisition unit 121 acquires temperature information from the temperature sensor 30. Furthermore, in step S101, the property acquisition unit 131 acquires property information indicating the properties of the lubricating oil from the property sensor 40. The electrical characteristic acquisition unit 111 outputs the acquired electrical characteristic information to the electrical characteristic temperature correction determination unit 112 and the storage unit 200, and the process proceeds to step S102. The temperature acquisition unit 121 outputs the acquired temperature information to the moving average value calculation unit 140, the abnormal state determination unit 150, and the storage unit 200, and the process proceeds to step S109. The property acquisition unit 131 outputs the acquired property information to the property temperature correction determination unit 132 and the storage unit 200, and the process proceeds to step S106.

[0077] In step S102, the electrical characteristic temperature correction determination unit 112 determines whether or not the electrical characteristic information requires temperature correction, based on the temperature information acquired by the temperature acquisition unit 121 and the electrical characteristic information acquired by the electrical characteristic acquisition unit 111. If the electrical characteristic temperature correction determination unit 112 determines that the electrical characteristic information requires temperature correction (YES in step S102), the control unit 100 proceeds to the processing of S103. If the electrical characteristic temperature correction determination unit 112 determines that the electrical characteristic information does not require temperature correction (NO in step S102), the control unit 100 proceeds to the processing of steps S104 and S105.

[0078] In step S103, if the electrical characteristic temperature correction determination unit 112 determines that the electrical characteristic information needs temperature correction, the electrical characteristic temperature correction unit 113 performs temperature correction on the electrical characteristic information. The electrical characteristic temperature correction unit 113 outputs the temperature-corrected electrical characteristic information to the minimum value determination unit 114, the electrical characteristic comparison unit 115, and the storage unit 200, and then proceeds to steps S104 and S105.

[0079] In step S104, the minimum value determination unit 114 determines the minimum value of the lubricant. The minimum value determination unit 114 outputs the determination result of the determined minimum value to the abnormal state determination unit 150 and the storage unit 200. For example, in step S104, the minimum value determination unit 114 determines whether or not the electrical characteristic has reached a minimum value, and outputs the determination result to the abnormal state determination unit 150 and the storage unit 200.

[0080] In step S105, the electrical characteristic comparing unit 115 compares the current value and the past value of the electrical characteristic. Specifically, the electrical characteristic comparing unit 115 uses the electrical characteristic information acquired in step S101, or, if temperature correction has been performed, the electrical characteristic information temperature-corrected in step S103, as the current value. The electrical characteristic comparing unit 115 also acquires past values ​​to be compared from the storage unit 200. Then, the electrical characteristic comparing unit 115 compares the current value and the past value. The electrical characteristic comparing unit 115 outputs the comparison result of the electrical characteristic information to the abnormal state determining unit 150 and the storage unit 200, and proceeds to step S110. Note that in step S105, the moving average values ​​calculated by the moving average calculating unit 140 may be used as the current value and the past value of the electrical characteristic. In this case, the moving average value of the electrical characteristic information is calculated by the moving average calculating unit 140 before step S105. Note that, as a modification of the present embodiment, step S105 may be omitted depending on the result of step S104, for example. In other words, the comparison between the current value and the past value of the electrical characteristic performed for step S109 may be performed after it is determined in step S104 that the electrical characteristic has reached a minimum value, but may not be performed if it is determined that the electrical characteristic has not reached a minimum value.

[0081] In step S106, the property temperature correction determination unit 132 determines whether or not the property information requires temperature correction, based on the temperature information acquired by the temperature acquisition unit 121 and the property information acquired by the property acquisition unit 131. If the property temperature correction determination unit 132 determines that the property information requires temperature correction (YES in step S106), the control unit 100 proceeds to the process of S107. If the property temperature correction determination unit 132 determines that the property information does not require temperature correction (NO in step S106), the control unit 100 proceeds to the process of step S108.

[0082] In step S107, if the property temperature correction determination unit 132 determines that the property information needs temperature correction, the property temperature correction unit 133 performs temperature correction on the property information. The property temperature correction unit 133 outputs the temperature-corrected property information to the property comparison unit 134 and the storage unit 200, and the process proceeds to step S108.

[0083] In step S108, the property comparison unit 134 compares the current value and the past value of the property. Specifically, the property comparison unit 134 uses the property information acquired in step S101, or, if temperature correction has been performed, the property information temperature-corrected in step S107, as the current value. The property comparison unit 134 also acquires past values ​​to be compared from the storage unit 200. Thereafter, the property comparison unit 134 compares the current value and the past value. The property comparison unit 134 outputs the result of the comparison of the property information to the abnormal state determination unit 150 and the storage unit 200, and the process proceeds to step S109. Note that in step S108, moving average values ​​calculated by the moving average value calculation unit 140 may be used as the current value and past value of the property. In this case, the moving average value of the property information is calculated by the moving average value calculation unit 140 before step S108.

[0084] In step S109, the abnormal state determination unit 150 determines an abnormal state of the lubricant based on the minimum value determination result by the minimum value determination unit 114 in step S104, the comparison result of the electrical properties by the electrical property comparison unit 115 in step S105, the temperature information acquired by the temperature acquisition unit 121 in step S101, and the comparison result of the properties by the property comparison unit 134 in step S108. The abnormal state determination unit 150 outputs the determination result of the abnormal state to the display control unit 160 and the storage unit 200, and proceeds to step S110. Note that, depending on the result of step S104, some of the steps in step S109 may be omitted. In other words, among the abnormal state determinations performed in step S109, the determination of an abnormal state that may be affected by the electrical properties (e.g., deterioration, soot contamination) is performed if it is determined in step S104 that the electrical properties have reached a minimum value, but is not performed if it is determined that the electrical properties have not reached a minimum value.

[0085] In step S110, the display control unit 160 causes the display unit 300 to display the abnormal state determination result determined by the abnormal state determination unit 150. In step S110, the display unit 300 displays the abnormal state determination result by the abnormal state determination unit 150 output from the display control unit 160.

[0086] [Software implementation example] The functions of the lubricant oil abnormality detection device 10 (hereinafter referred to as the "device") can be realized by a program that causes a computer to function as the device, and a program that causes a computer to function as each control block of the device (particularly each part included in the control unit 100).

[0087] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program to realize each function described in each of the above embodiments.

[0088] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the system via any wired or wireless transmission medium.

[0089] Furthermore, some or all of the functions of the control blocks can be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of the control blocks can also be realized by, for example, a quantum computer.

[0090] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0091] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0092] [Note] From the above description, the present invention can be understood, for example, as follows: It should be noted that, to facilitate understanding of the present invention, reference numerals in the accompanying drawings are conveniently placed in parentheses, but this does not mean that the present invention is limited to the illustrated embodiments.

[0093] The lubricant abnormality detection system (1) according to aspect 1 includes an electrical characteristic acquisition unit (111) that acquires electrical characteristic information indicating the electrical characteristics of the lubricant, a minimum value determination unit (114) that determines a minimum value, which is the minimum value when the electrical characteristic of the lubricant decreases with use and then begins to increase, and an abnormal state determination unit (150) that determines an abnormal state of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit (111) and the determination result of the minimum value by the minimum value determination unit.

[0094] The lubricant oil abnormality detection system (1) according to aspect 2 is the same as in aspect 1, and further includes at least one of a temperature acquisition unit (121) that acquires temperature information indicating the temperature of the lubricant oil and a property acquisition unit (131) that acquires property information indicating the property of the lubricant oil, and the abnormal state determination unit (150) may determine the abnormal state further based on the temperature information acquired by the temperature acquisition unit (121) and the property information acquired by the property acquisition unit (131).

[0095] The lubricant oil abnormality detection system (1) according to aspect 3 may further include, in aspect 2, a moving average value calculation unit (140) that calculates a moving average value based on a plurality of values ​​per unit time of at least one selected from the electrical characteristic information, the temperature information, and the property information, and the abnormal state determination unit (150) may determine the abnormal state further based on the moving average value.

[0096] In the lubricant abnormality detection system (1) according to a fourth aspect, in the second or third aspect, the property may be at least one of viscosity and density.

[0097] The lubricant oil abnormality detection system (1) according to aspect 5 may be any one of aspects 1 to 4, wherein the abnormal state is at least one selected from deterioration, fuel contamination, soot contamination, metal contamination, and water contamination.

[0098] The lubricant abnormality detection system (1) according to aspect 6 may further include, in aspect 2, an electrical characteristic temperature correction determination unit (112) that determines whether or not temperature correction is required for the electrical characteristic information based on the temperature information acquired by the temperature acquisition unit (121) and the electrical characteristic information acquired by the electrical characteristic acquisition unit (111), and an electrical characteristic temperature correction unit (113) that performs temperature correction for the electrical characteristic information when the electrical characteristic temperature correction determination unit (112) determines that temperature correction is required for the electrical characteristic information.

[0099] The lubricant oil abnormality detection system (1) according to aspect 7 may further include, in aspect 2, a property temperature correction determination unit (132) that determines whether or not temperature correction is required for the property information based on the temperature information acquired by the temperature acquisition unit (121) and the property information acquired by the property acquisition unit (131), and a property temperature correction unit (133) that performs temperature correction for the property information when the property temperature correction determination unit (132) determines that temperature correction is required for the property information.

[0100] The lubricant oil abnormality detection system (1) according to aspect 8 may be any one of aspects 1 to 7, further comprising an electrical characteristic sensor (20) that measures the electrical characteristics to obtain the electrical characteristic information, and the electrical characteristic acquisition unit (111) may acquire the electrical characteristic information from the electrical characteristic sensor (20).

[0101] The lubricant oil abnormality detection system (1) according to aspect 9 may be any one of aspects 1 to 8, further comprising a display unit (300) that displays the abnormal state determination result by the abnormal state determination unit (150).

[0102] The lubricant oil abnormality detection device (10) according to aspect 10 includes an electrical characteristic acquisition unit (111) that acquires electrical characteristic information indicating the electrical characteristics of the lubricant oil, a minimum value determination unit (114) that determines a minimum value, which is the minimum value when the electrical characteristic of the lubricant oil decreases with use and then begins to increase, and an abnormal state determination unit (150) that determines an abnormal state of the lubricant oil based on the electrical characteristic information acquired by the electrical characteristic acquisition unit (111) and the determination result of the minimum value by the minimum value determination unit (114).

[0103] The lubricant abnormality detection method of aspect 11 is a lubricant abnormality detection method executed by one or more computers, and includes an electrical characteristic acquisition step (S101) of acquiring electrical characteristic information indicating the electrical characteristics of the lubricant, a minimum value determination step (S104) of determining a minimum value, which is the smallest value when the electrical characteristic of the lubricant decreases with use and then begins to increase, and an abnormal state determination step (S109) of determining an abnormal state of the lubricant based on the electrical characteristic information acquired in the electrical characteristic acquisition step and the determination result of the minimum value in the minimum value determination step.

[0104] The lubricant oil abnormality detection program of aspect 12 is a lubricant oil abnormality detection program for causing a computer to function as the lubricant oil abnormality detection device (10) of aspect 10, and is a lubricant oil abnormality detection program for causing a computer to function as the electrical characteristic acquisition unit (111), the minimum value determination unit (114), and the abnormal state determination unit (150).

[0105] A recording medium according to a thirteenth aspect is a computer-readable recording medium on which the lubricant oil abnormality detection program according to the twelfth aspect is recorded.

[0106] [Reference example] A reference example of the present invention will be described below.

[0107] (Reference example 1) An Indiana Stirring Oxidation Test (ISOT) in accordance with JIS K2514-1:2013 was conducted at 165.5°C without a catalyst using gas engine oil A containing 0.29 wt% calcium and a calcium detergent (metallic detergent). Portions of gas engine oil A were sampled and cooled to 30°C at 0, 72, 96, and 120 hours after the start of the test. The capacitance at 30°C was measured using a platinum interdigitated electrode (manufactured by BAS) with a 20 μm gap between the electrodes. The capacitance in air was also measured in the same manner as the blank. The capacitance of gas engine oil A / the capacitance of the blank was calculated as the capacitance ratio. Figure 3 shows a graph showing the capacitance ratio at 30°C versus the degradation time of gas engine oil A during the ISOT test.

[0108] (Reference example 2) Gas engine oil B was used, which had the same composition as gas engine oil A, except that the calcium content of the calcium detergent was 0.10 wt%. The ISOT test was otherwise carried out in the same manner as in Reference Example 1. The capacitance was measured 0 hours, 24 hours, 48 ​​hours, and 72 hours after the start of the test. Figure 4 is a graph showing the capacitance ratio at 30°C versus the ISOT test deterioration time for gas engine oil B.

[0109] (Reference example 3) An engine oil containing no metallic detergent was used. The ISOT test was conducted in the same manner as in Reference Example 1. The capacitance was measured 0 hours, 48 ​​hours, 72 hours, and 96 hours after the start of the test. Figure 5 is a graph showing the capacitance ratio at 30°C versus the ISOT test deterioration time for engine oil containing no metallic detergent.

[0110] (result) In Reference Example 1, it was found that gas engine oil A had a minimum capacitance ratio after 72 hours. In Reference Example 2, it was found that gas engine oil B had a minimum capacitance ratio after 24 hours. Furthermore, in Reference Example 3, it was found that engine oils containing no metal-based detergents did not have a minimum point. The results of Reference Examples 1 to 3 revealed that lubricating oils containing metal-based detergents have a minimum capacitance ratio, but do not have a minimum capacitance ratio when not containing metal-based detergents.

[0111] Electrical properties depend on the type and amount of polar substances; a decrease in the amount of polar substances leads to a decrease in capacitance, while an increase in the amount of polar substances leads to an increase in electrical properties. Because metal-based detergents are polar substances, it is believed that the capacitance decreases as the metal-based detergent is consumed and its amount decreases. Therefore, in the case of gas engine oil A and gas engine oil B, which contain metal-based detergents, the decrease in capacitance ratio is believed to be due to the consumption (deterioration) of the metal-based detergent. Furthermore, since many of the deteriorated substances in the main component oil and additives other than the metal-based detergent are polar substances, it is believed that the electrical properties increase as the main component oil and additives other than the metal-based detergent deteriorate and their amounts increase. Therefore, the increase in capacitance after passing the minimum point for gas engine oil A and gas engine oil B, which contain metal-based detergents, is believed to be due to the deterioration of the main component oil and additives other than the metal-based detergent. Furthermore, the increase in capacitance from the initial value for engine oil without metal-based detergents is believed to be due to the deterioration of the main component oil and additives. [Explanation of symbols]

[0112] 1. Lubricant abnormality detection system 10. Lubricant abnormality detection device 20 Electrical property sensor 30 Temperature Sensor 40 Property sensor 100 control unit 110 Electrical Characteristics Unit 111 Electrical characteristics acquisition unit 112 Electrical characteristics temperature correction judgment unit 113 Electrical characteristics temperature compensation section 114 Minimum value determination unit 115 Electrical characteristics comparison section 120 temperature units 121 Temperature acquisition section 130 Property Unit 131 Property acquisition department 132 Property temperature correction judgment section 133 Property temperature correction section 134 Property comparison section 140 Moving average value calculation section 150 Abnormal state determination unit 160 Display control unit 200 Storage section 300 Display

Claims

1. an electrical characteristic acquisition unit that acquires electrical characteristic information indicating electrical characteristics of the lubricating oil; a minimum value determination unit that determines a minimum value when the electrical characteristic of the lubricating oil decreases with use and then starts to increase; a lubricant abnormality detection system comprising: an abnormality state determination unit that determines an abnormal state of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit and the result of the minimum value determination by the minimum value determination unit.

2. The lubricating oil temperature sensor further includes at least one of a temperature acquisition unit that acquires temperature information indicating the temperature of the lubricating oil and a property acquisition unit that acquires property information indicating the property of the lubricating oil, The lubricant abnormality detection system according to claim 1, wherein the abnormal state determination unit determines the abnormal state further based on the temperature information acquired by the temperature acquisition unit and the property information acquired by the property acquisition unit.

3. a moving average value calculation unit that calculates a moving average value based on a plurality of values ​​per unit time of at least one selected from the electrical characteristic information, the temperature information, and the property information; The lubricant abnormality detection system according to claim 2 , wherein the abnormality determination unit determines the abnormality further based on the moving average value.

4. The lubricant abnormality detection system according to claim 2 , wherein the property is at least one of viscosity and density.

5. The lubricant abnormality detection system according to claim 1 , wherein the abnormal state is at least one selected from the group consisting of deterioration, fuel contamination, soot contamination, metal contamination, and water contamination.

6. an electrical characteristic temperature correction determination unit that determines whether temperature correction is required for the electrical characteristic information based on the temperature information acquired by the temperature acquisition unit and the electrical characteristic information acquired by the electrical characteristic acquisition unit; The lubricant abnormality detection system according to claim 2, further comprising: an electrical characteristic temperature correction unit that performs temperature correction of the electrical characteristic information when the electrical characteristic temperature correction determination unit determines that temperature correction is necessary for the electrical characteristic information.

7. a property temperature correction determination unit that determines whether or not temperature correction is required for the property information based on the temperature information acquired by the temperature acquisition unit and the property information acquired by the property acquisition unit; The lubricant abnormality detection system according to claim 2, further comprising a property temperature correction unit that performs temperature correction of the property information when the property temperature correction determination unit determines that temperature correction is necessary for the property information.

8. further comprising an electrical characteristic sensor that measures the electrical characteristic to obtain the electrical characteristic information; The lubricant abnormality detection system according to claim 1 , wherein the electrical characteristic acquisition unit acquires the electrical characteristic information from the electrical characteristic sensor.

9. The lubricant oil abnormality detection system according to any one of claims 1 to 8, further comprising a display unit that displays the abnormal state determination result by the abnormal state determination unit.

10. an electrical characteristic acquisition unit that acquires electrical characteristic information indicating electrical characteristics of the lubricating oil; a minimum value determination unit that determines a minimum value when the electrical characteristic of the lubricating oil decreases with use and then starts to increase; a lubricant abnormality detection device comprising: an abnormality state determination unit that determines an abnormal state of the lubricant based on the electrical characteristic information acquired by the electrical characteristic acquisition unit and the minimum value determination result by the minimum value determination unit.

11. A lubricant abnormality detection method executed by one or more computers, comprising: an electrical characteristic acquisition step of acquiring electrical characteristic information indicating electrical characteristics of the lubricating oil; a minimum value determination step of determining a minimum value, which is the minimum value when the electrical property of the lubricating oil decreases with use and then starts to increase; a lubricant abnormality detection method including an abnormality determination step of determining an abnormal state of the lubricant based on the electrical characteristic information acquired in the electrical characteristic acquisition step and the determination result of the minimum value in the minimum value determination step.

12. A lubricant abnormality detection program for causing a computer to function as the lubricant abnormality detection device described in claim 10, wherein the lubricant abnormality detection program causes a computer to function as the electrical characteristic acquisition unit, the minimum value determination unit, and the abnormal state determination unit.

13. A computer-readable recording medium on which the lubricant oil abnormality detection program according to claim 12 is recorded.

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