JP2020133643A - Abnormality detection device and abnormality detection method - Google Patents

Abstract

To provide an abnormality detection device and abnormality detection method capable of detecting abnormality with high accuracy.SOLUTION: An abnormality detection device 1 comprises a detection unit 22 and an abnormality determination unit 24. The detection unit detects an actual current flowing in switching of a switching valve that switches flow passages for fluid output from a pump of a fluid system. The abnormality determination unit determines an abnormality of the fluid system, based on the comparison result of the actual current and the estimated current required in the switching of the switching valve calculated based on a setting output for fluid in the pump.SELECTED DRAWING: Figure 2

Description

The present invention relates to an abnormality detection device and an abnormality detection method.

Conventionally, for example, an abnormality determining device for determining an abnormality of a cooling system for cooling an internal combustion engine is known. Some abnormality determination devices of this type perform abnormality determination based on the rotation speed of a pump that generates cooling water and the power consumption of the entire cooling system (see, for example, Patent Document 1).

JP-A-2017-057746

However, in the prior art, there is room for improvement in detecting an abnormality in the cooling system with high accuracy. Specifically, in the prior art, since the power consumption of the entire cooling system is monitored, if the current change due to the abnormality of the cooling system is minute, there is a possibility that the abnormality cannot be detected with high accuracy.

The present invention has been made in view of the above, and an object of the present invention is to provide an abnormality detection device and an abnormality detection method capable of detecting an abnormality with high accuracy.

In order to solve the above-mentioned problems and achieve the object, the abnormality detection device according to the present invention includes a detection unit and an abnormality determination unit. The detection unit detects the actual current that flows when the switching valve that switches the flow path of the fluid output from the pump of the fluid system is switched. The abnormality determination unit determines an abnormality in the fluid system based on a comparison result between the estimated current required for switching the switching valve calculated based on the set output of the fluid in the pump and the actual current. ..

According to the present invention, anomalies can be detected with high accuracy.

FIG. 1A is a diagram showing an outline of an abnormality detection method according to an embodiment. FIG. 1B is a diagram showing an outline of an abnormality detection method according to an embodiment. FIG. 2 is a block diagram showing a configuration of an abnormality detection device according to an embodiment. FIG. 3 is a diagram for explaining the determination process of the abnormality determination unit. FIG. 4 is a diagram for explaining the determination process of the abnormality determination unit. FIG. 5 is a diagram for explaining the determination process of the abnormality determination unit. FIG. 6 is a flowchart showing a processing procedure of the abnormality detection process executed by the abnormality detection device according to the embodiment.

Hereinafter, embodiments of the abnormality detection device and the abnormality detection method disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

First, the outline of the abnormality detection method according to the embodiment will be described with reference to FIGS. 1A and 1B. 1A and 1B are diagrams showing an outline of an abnormality detection method according to an embodiment. In the following, the abnormality detection device according to the embodiment is a cooling system that cools the battery and the air conditioner in the vehicle, and detects an abnormality in the cooling system that switches the cooling destination path of the cooling water output by the pump with a switching valve. The case will be described.

The cooling system is an example, and any fluid system equipped with a pump for outputting a fluid (not limited to water but also oil or the like) and a switching valve for switching a fluid path can be adopted.

As shown in FIG. 1A, the cooling system S according to the embodiment includes an abnormality detection device 1, a control device 100, a pump 110, a valve 120, a battery 130, and an air conditioner 140.

The control device 100 controls the pump 110 and the valve 120. Specifically, the control device 100 controls the pump 110 based on the set output of the cooling water CW in the pump 110 (for example, the rotation speed of the pump 110, the output flow rate of the cooling water CW, the output flow velocity, etc.).

The set output is determined based on, for example, the temperature of the battery 130 or the set temperature of the air conditioner 140. Further, the control device 100 outputs information regarding the setting output to the abnormality detection device 1.

Further, the control device 100 controls to switch the flow path FP of the cooling water CW by driving the valve 120 with an electric current according to the cooling timing of each of the battery 130 and the air conditioner 140. Specifically, the control device 100 outputs a switching signal indicating the switching timing of the valve 120 and a current required for switching to the valve 120.

The pump 110 is a so-called water pump that outputs (circulates) the cooling water CW. The valve 120 is a switching valve that switches the flow path FP of the cooling water CW based on the switching signal of the control device 100. The valve 120 is, for example, a solenoid valve. In the current drive of the valve 120, the higher the output of the cooling water CW, the higher the actual current at the time of switching.

The battery 130 is a battery that supplies electric power to each electronic device of the vehicle. The air conditioner 140 is a device that adjusts the temperature inside the vehicle interior of the vehicle.

The abnormality detection device 1 according to the embodiment detects an abnormality in the cooling system S by executing the abnormality detection method according to the embodiment. Specifically, the abnormality detection device 1 according to the embodiment first detects the actual current that flows when the valve 120 is switched.

Then, the abnormality detection device 1 according to the embodiment is a cooling system based on a comparison result between the estimated current required at the time of switching the valve 120 calculated based on the set output acquired from the control device 100 and the detected actual current. Determine the abnormality of S.

FIG. 1B shows graphs of estimated current and actual current. Note that FIG. 1B shows an actual current when the cooling system S is abnormal and an actual current when the cooling system S is normal.

As shown in FIG. 1B, when the cooling system S is normal, the detected actual current and the estimated current have substantially the same current value. This indicates that there is no error between the set output instructed by the control device 100 and the actual output of the pump 110, and that the valve 120 is also switched normally. Therefore, in the abnormality detection method according to the embodiment, when the actual current and the estimated current are substantially the same, it is determined that the cooling system S is normal.

On the other hand, when the cooling system S is abnormal, there is a discrepancy between the detected actual current and the estimated current. In FIG. 1B, the current value at which the actual current (abnormality) is the peak value is higher than the estimated current. This indicates that more force (current) is required to switch the valve 120 than expected.

The causes of this are, for example, that the actual output of the pump 110 is higher than the set output, that the valve 120 is in a locked state (or that it is difficult to move due to foreign matter), and that the wiring through which the current flows is broken. What you are doing, etc.

Therefore, in the abnormality detection method according to the embodiment, when the deviation between the actual current and the estimated current satisfies a predetermined condition, the cooling system S is determined to be abnormal.

That is, in the abnormality detection method according to the embodiment, in the cooling system S, the abnormality is detected by the actual current of the valve 120, so that the abnormality is detected by monitoring the power consumption of the entire cooling system as in the conventional case. Therefore, minute current changes can be captured with high sensitivity. Therefore, according to the abnormality detection method according to the embodiment, the abnormality can be detected with high accuracy.

The abnormality detection device 1 according to the embodiment can determine the type of abnormality according to the degree of deviation between the actual current and the estimated current, and the details of this point will be described later.

Next, the configuration of the abnormality detection device 1 according to the embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the abnormality detection device 1 according to the embodiment. As shown in FIG. 2, the abnormality detection device 1 according to the embodiment is connected to the control device 100 and the current sensor 200.

Note that FIG. 2 shows a case where the abnormality detection device 1 is configured separately from the control device 100, but the present invention is not limited to this, and the abnormality detection device 1 may be integrally configured with the control device 100.

The current sensor 200 is a sensor that measures the actual current flowing through the valve 120.

As shown in FIG. 2, the abnormality detection device 1 according to the embodiment includes a control unit 2 and a storage unit 3. The control unit 2 includes an acquisition unit 21, a detection unit 22, a calculation unit 23, and an abnormality determination unit 24. The storage unit 3 stores the map information 31.

Here, the abnormality detection device 1 includes, for example, a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a data flash, an input / output port, and various circuits.

The CPU of the computer functions as the acquisition unit 21, the detection unit 22, the calculation unit 23, and the abnormality determination unit 24 of the control unit 2, for example, by reading and executing the program stored in the ROM.

Further, at least one or all of the acquisition unit 21, the detection unit 22, the calculation unit 23, and the abnormality determination unit 24 of the control unit 2 are hardware such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array). It can also be configured with.

Further, the storage unit 3 corresponds to, for example, a RAM or a data flash. The RAM or data flash can store map information 31, information on various programs, and the like. The abnormality detection device 1 may acquire the above-mentioned program and various information via another computer or a portable recording medium connected by a wired or wireless network.

The map information 31 stored in the storage unit 3 is a diagram showing the relationship between the set output of the pump 110 and the current value. In the map information 31, there is a positive correlation between the set output and the current value. The map information 31 is generated in advance by an experiment or the like.

This map information 31 is used for conversion processing from the set output to the current value (conversion processing from the current value to the output of the pump 110) by the calculation unit 23 and the abnormality determination unit 24, which will be described later.

The acquisition unit 21 acquires various types of information. For example, the acquisition unit 21 acquires information on the setting output from the control device 100 and outputs it to the calculation unit 23. Further, the acquisition unit 21 acquires the value of the actual current of the valve 120 measured by the current sensor and outputs it to the detection unit 22. Further, the acquisition unit 21 acquires information on the switching signal indicating the switching timing of the valve 120 from the control device 100 and outputs the information to the detection unit 22.

The detection unit 22 detects the actual current that flows when the valve 120 that switches the flow path FP of the cooling water CW output from the pump 110 of the cooling system S is switched.

Specifically, the detection unit 22 detects the actual current flowing during the period when the switching signal is on as the actual current at the time of switching. The detection unit 22 outputs information regarding the detected actual current to the abnormality determination unit 24.

The calculation unit 23 calculates the estimated current required when switching the valve 120 based on the information regarding the set output acquired by the acquisition unit 21. Specifically, the calculation unit 23 calculates the current value corresponding to the acquired set output as the estimated current by using the map information 31 stored in the storage unit 3.

The estimated current is not limited to the case where the calculation unit 23 calculates, and the abnormality detection device 1 may acquire the estimated current calculated by the control device 100.

The calculation unit 23 outputs the information regarding the calculated estimated current to the abnormality determination unit 24.

The abnormality determination unit 24 determines the abnormality of the cooling system S based on the comparison result between the estimated current calculated by the calculation unit 23 and the actual current detected by the detection unit 22. Here, the determination process by the abnormality determination unit 24 will be specifically described with reference to FIGS. 3 to 5.

3 to 5 are diagrams for explaining the determination process of the abnormality determination unit 24. Note that FIGS. 3 and 5 show the actual current of the cooling system S when the valve 120 is abnormal, and FIG. 4 shows the actual current when the pump 110 is abnormal.

As shown in FIG. 3, the abnormality determination unit 24 determines that the valve 120 is abnormal when the absolute value of the difference D11 between the peak value of the actual current and the peak value of the estimated current is equal to or greater than the predetermined first threshold value TH11. judge.

That is, the abnormality determination unit 24 determines that the valve 120 is abnormal when a high actual current of the first threshold value TH11 or higher flows based on the peak value of the estimated current. More specifically, in such a case, the abnormality determination unit 24 determines that the valve 120 is in a locked state or the drive circuit of the valve 120 is short-circuited.

In this way, when a large current that should not normally flow when switching the valve 120 flows due to a locked state or a circuit short circuit, the abnormality of the valve 120 is detected to detect the abnormality with high accuracy. Can be done.

Further, as shown in FIG. 3, when the absolute value of the difference D12 between the peak value of the actual current and the peak value of the estimated current is equal to or greater than the predetermined first threshold value TH12, the abnormality determination unit 24 causes an abnormality in the valve 120. Judge that there is.

That is, the abnormality determination unit 24 determines that the valve 120 is abnormal when a minute actual current of the first threshold value TH12 or more flows based on the peak value of the estimated current. More specifically, in such a case, the abnormality determination unit 24 determines that the wiring that supplies the current to the valve 120 is in a broken state.

In this way, when the actual current that is lower than the current that should normally flow when the valve 120 is switched flows due to the disconnection, the abnormality is detected by detecting the abnormality of the valve 120 with high accuracy. can do.

Further, the abnormality determination unit 24 determines whether the abnormality type of the valve 120 is a locked state (or a circuit short circuit) or a disconnection depending on whether the detected actual current is higher or lower than the estimated current. be able to.

Further, as shown in FIG. 4, in the abnormality determination unit 24, the absolute value of the difference D21 between the peak value of the actual current and the peak value of the estimated current is less than the first threshold value TH11 and equal to or more than the second threshold value TH21. In this case, it is determined that the pump 110 is abnormal.

That is, when the abnormality determination unit 24 flows a moderately high actual current less than the first threshold value TH11 and more than the second threshold value TH21 with reference to the peak value of the estimated current, the valve 120 is abnormal. Judge that there is. More specifically, in such a case, the abnormality determination unit 24 determines that the abnormality is a state in which the flow rate, which is the actual output of the pump 110, is larger than the set output.

Further, as shown in FIG. 4, in the abnormality determination unit 24, the absolute value of the difference D22 between the peak value of the actual current and the peak value of the estimated current is less than the first threshold value TH12 and greater than or equal to the second threshold value TH22. In this case, it is determined that the pump 110 is abnormal.

That is, the abnormality determination unit 24 is an abnormality of the valve 120 when a moderately low actual current less than the first threshold value TH12 and more than the second threshold value TH22 flows based on the peak value of the estimated current. Is determined. More specifically, in such a case, the abnormality determination unit 24 determines that the flow rate, which is the actual output of the pump 110, is less than the set output.

As described above, the abnormality determination unit 24 can detect the output abnormality of the pump 110 with high accuracy by performing the abnormality determination using the first threshold values TH11 and TH12 and the second threshold values TH21 and TH22.

Further, the abnormality determination unit 24 can accurately determine whether the actual output of the pump 110 is larger or smaller than the set output, depending on whether the detected actual current is higher or lower than the estimated current. That is, the abnormality determination unit 24 can easily determine the type of output abnormality of the pump 110.

Further, the abnormality determination unit 24 determines whether or not the absolute values of the differences D11, D12, D21, and D22 between the peak value of the actual current and the peak value of the estimated current are equal to or greater than the first threshold values TH11 and TH12. Therefore, it is possible to easily determine whether the cause of the abnormality of the cooling system S is the pump 110 or the valve 120.

Next, as shown in FIG. 5, when the peak time of the actual current is later than the peak time of the estimated current by a predetermined delay threshold value or more, the abnormality determination unit 24 determines that the valve 120 is abnormal.

That is, the abnormality determination unit 24 determines that the valve 120 is abnormal when the delay time T1 of the peak time of the actual current is equal to or greater than the delay threshold value based on the peak time of the estimated current. Specifically, in such a case, the abnormality determination unit 24 determines that the switching delay state of the valve 120 is abnormal due to, for example, biting of foreign matter or the like.

In this way, the abnormality determination unit 24 can detect a slight deviation in the operation of the valve 120, so that a failure of the valve 120 can be detected in advance.

Then, when the abnormality determination unit 24 determines that the abnormality is determined by the determination processes shown in FIGS. 3 to 5, the abnormality determination unit 24 notifies the outside of the abnormality and stores the information indicating the abnormality.

Specifically, the abnormality determination unit 24 notifies the control device 100 of the abnormality location (pump 110 or valve 120) and the type of abnormality, and stores the abnormality in the control device 100. In the case of an output abnormality of the pump 110, the abnormality determination unit 24 calculates the actual output from the actual current based on the map information 31, and notifies the control device 100 of the information regarding the deviation from the set output.

Next, the processing procedure of the processing executed by the abnormality detection device 1 according to the embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing a processing procedure of the abnormality detection process executed by the abnormality detection device 1 according to the embodiment.

As shown in FIG. 6, first, the detection unit 22 detects the actual current flowing when the valve 120 is switched (S101). Subsequently, the calculation unit 23 calculates the estimated current required when switching the valve 120 based on the set output of the cooling water CW in the pump 110 (S102).

Subsequently, the abnormality determination unit 24 calculates the difference between the actual current and the estimated current and the delay time (S103). The difference is the absolute value of the difference between the peak value of the actual current and the peak value of the estimated current. The delay time is the time difference between the peak time of the actual current and the peak time of the estimated current.

The abnormality determination unit 24 determines whether or not the peak time of the actual current is delayed (S104). Specifically, the abnormality determination unit 24 determines whether or not the delay time is equal to or greater than the delay threshold value.

When the abnormality determination unit 24 determines that the peak time of the actual current is delayed (S104: Yes), it determines that the valve 120 is abnormal due to the switching delay due to the biting of foreign matter (S105), and ends the process. ..

Further, the abnormality determination unit 24 determines whether or not the calculated difference is equal to or greater than the first threshold value when the peak time of the actual current is not delayed (S104: No) (S106).

When the abnormality determination unit 24 determines that the difference is equal to or greater than the first threshold value (S106: Yes), it determines that the valve 120 is abnormal due to a locked state, a circuit short circuit, or a disconnection (S107), and performs processing. finish.

Further, when the abnormality determination unit 24 determines that the difference is less than the first threshold value (S106: No), the abnormality determination unit 24 determines whether or not the difference is equal to or more than the second threshold value (S108).

When the abnormality determination unit 24 determines that the difference is equal to or greater than the second threshold value (S108: Yes), it determines that the pump 110 is abnormal due to an output deviation such as a flow rate (S109), and ends the process.

Further, when the abnormality determination unit 24 determines that the difference is less than the second threshold value (S108: No), the abnormality determination unit 24 determines that the cooling system S is normal (S110), and ends the process.

As described above, the abnormality detection device 1 according to the embodiment includes a detection unit 22 and an abnormality determination unit 24. The detection unit 22 detects the actual current that flows when the valve 120 that switches the flow path FP of the cooling water CW output from the pump 110 of the cooling system S is switched. The abnormality determination unit 24 determines the abnormality of the cooling system S based on the comparison result between the estimated current required at the time of switching the valve 120 calculated based on the set output of the cooling water CW in the pump 110 and the actual current. As a result, the abnormality can be detected with high accuracy.

In the above-described embodiment, the switching destinations of the valve 120 are two locations, the battery 130 and the air conditioner 140, but the switching destinations may be three or more locations.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

1 Abnormality detection device 2 Control unit 3 Storage unit 21 Acquisition unit 22 Detection unit 23 Calculation unit 24 Abnormality judgment unit 31 Map information 100 Control device 110 Pump 120 Valve 130 Battery 140 Air conditioner 200 Current sensor

Claims (5)

A detector that detects the actual current that flows when switching the switching valve that switches the flow path of the fluid output from the pump of the fluid system, and
It is provided with an abnormality determination unit that determines an abnormality of the fluid system based on a comparison result between the estimated current required for switching the switching valve calculated based on the set output of the fluid in the pump and the actual current. Anomaly detection device characterized by this. The abnormality determination unit
The first aspect of claim 1, wherein when the absolute value of the difference between the peak value of the actual current and the peak value of the estimated current is equal to or greater than a predetermined first threshold value, it is determined that the switching valve is abnormal. Abnormality detection device. The abnormality determination unit
The abnormality detection device according to claim 2, wherein when the absolute value of the difference is less than the predetermined first threshold value and greater than or equal to the predetermined second threshold value, it is determined that the pump is abnormal. .. The abnormality determination unit
According to any one of claims 1 to 3, wherein when the peak time of the actual current is later than the peak time of the estimated current by a predetermined delay threshold value or more, it is determined that the switching valve is abnormal. The described anomaly detector. A detection process that detects the actual current that flows when switching the switching valve that switches the flow path of the fluid output from the pump of the fluid system, and
Includes an abnormality determination step of determining an abnormality of the fluid system based on a comparison result between the estimated current required for switching the switching valve calculated based on the set output of the fluid in the pump and the actual current. An abnormality detection method characterized by this.

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