JP2021124112A - Abnormality determination device and abnormality determination method - Google Patents

Abstract

To provide an abnormality determination device and an abnormality determination method capable of highly accurately determining an abnormality of a catalyst.SOLUTION: An abnormality determination device includes an acquisition section, an estimation section, a calculation section and a determination section. The acquisition section acquires an operating state of an internal combustion engine immediately before a vehicle is stopped. The estimation section estimates heat quantity of an air-fuel ratio sensor that detects an air-fuel ratio of exhaust gas purified by a purification catalyst purifying exhaust gas of the internal combustion engine by heating using a heater, on the basis of the operating state acquired by the acquisition section at start of the vehicle. The calculation section calculates a required time that is required until the air-fuel ratio sensor is activated on the basis of the heat quantity at start of the vehicle estimated by the estimation section. The determination section determines presence/absence of an abnormality related to heating of the purification catalyst on the basis of the required time calculated by the calculation section.SELECTED DRAWING: Figure 2

Description

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

Conventionally, a system for purifying exhaust gas emitted from an internal combustion engine by an electric heating catalyst (EHC) mounted on a vehicle is known. In this type of system, the deterioration of the catalyst is determined based on the integrated intake amount corresponding to the amount of heat required to activate the catalyst (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 9-004438

However, since the initial calorific value of the catalyst varies greatly depending on the operating state of the internal combustion engine immediately before the stop, there is a possibility that the deterioration of the catalyst cannot be determined with high accuracy by the conventional integrated intake air amount.

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

In order to solve the above-mentioned problems and achieve the object, the abnormality determination device according to the present invention includes an acquisition unit, an estimation unit, a calculation unit, and a determination unit. The acquisition unit acquires the operating state of the internal combustion engine immediately before the vehicle stops. At the time of starting the vehicle, the estimation unit is empty of the exhaust gas purified by a purification catalyst that purifies the exhaust gas of the internal combustion engine by heating with a heater based on the operating state acquired by the acquisition unit. Estimate the amount of heat of the air-fuel ratio sensor that detects the fuel ratio. The calculation unit calculates the time required for the air-fuel ratio sensor to be activated based on the amount of heat estimated by the estimation unit at the time of starting the vehicle. The determination unit determines the presence or absence of an abnormality related to heating of the purification catalyst based on the required time calculated by the calculation unit.

According to the present invention, the abnormality of the catalyst can be determined with high accuracy.

FIG. 1 is a diagram showing an outline of an abnormality determination method according to an embodiment. FIG. 2 is a block diagram showing a configuration of an abnormality determination device according to an embodiment. FIG. 3A is a diagram showing an example of calorific value information. FIG. 3B is a diagram showing an example of map information. FIG. 4 is a diagram showing the processing contents of the determination unit. FIG. 5 is a diagram showing the processing content of the update unit. FIG. 6 is a flowchart showing a processing procedure of the entire processing executed by the abnormality determination device according to the embodiment. FIG. 7 is a flowchart showing a processing procedure of the abnormality determination process executed by the abnormality determination device according to the embodiment. FIG. 8 is a flowchart showing a processing procedure of the update process executed by the abnormality determination device according to the embodiment.

Hereinafter, embodiments of the abnormality determination device and the abnormality determination 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 determination method according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an outline of an abnormality determination method according to an embodiment. FIG. 1 shows an abnormality determination system S according to an embodiment. The abnormality determination system S according to the embodiment is mounted on a vehicle, for example.

As shown in FIG. 1, the abnormality determination system S according to the embodiment includes an abnormality determination device 1 and a purification device 100. The purification device 100 includes an engine 101, a catalyst unit 102, a power supply unit 1103, an underfloor catalyst 104, an exhaust heat recovery device 105, an A / F sensor 106, and an exhaust path 107.

The engine 101 is an internal combustion engine of a vehicle. The vehicle on which the engine 101 is mounted is a vehicle such as a hybrid vehicle or a range extender vehicle whose drive source is a motor driven by electric power generated by the engine 101.

The catalyst unit 102 purifies the exhaust gas G discharged from the engine 101. Specifically, the catalyst unit 102 includes an EHC (Electrical Heating Catalyst) 102a and an Rr catalyst 102b.

The EHC 102a is an electric heating catalyst provided downstream of the engine 101 via the exhaust path 107 and heated by an electric heater, and is a purification catalyst for purifying the exhaust gas G. EHC102a is, for example, a three-way catalyst.

The Rr catalyst 102b is a purification catalyst that purifies the exhaust gas G, and is, for example, a three-way catalyst. Specifically, the Rr catalyst 102b is provided downstream of the EHC102a and further purifies the exhaust gas G purified by the EHC102a.

The power supply unit 103 is a power source that supplies electric power to the catalyst unit 102. The power supply unit 103 transforms the electric power stored in the high-voltage battery (not shown) by a transformer and supplies it to the catalyst unit 102. As a result, the electric heater of the EHC102a generates heat, and the catalyst of the EHC102a and the Rr catalyst 102b are heated.

The underfloor catalyst 104 is provided downstream of the catalyst unit 102 via the exhaust path 107, and purifies the exhaust gas G purified by the Rr catalyst 102b. The underfloor catalyst 104 is, for example, a three-way catalyst.

The exhaust heat recovery device 105 is provided downstream of the underfloor catalyst 104 via the exhaust path 107, and exhausts the exhaust gas G purified by the underfloor catalyst 104. The exhaust gas G exhausted by the exhaust heat recovery device 105 is discharged to the outside of the vehicle.

The A / F sensor 106 is an air-fuel ratio sensor that is provided in the exhaust path 107 between the catalyst unit 102 and the underfloor catalyst 104 and detects the air-fuel ratio of the exhaust gas G purified by the catalyst unit 102.

The abnormality determination device 1 determines whether or not an abnormality has occurred in the purification device 100 by executing the abnormality determination method according to the embodiment. Specifically, the abnormality determination device 1 determines whether or not there is an abnormality in which the catalyst of the EHC102a is deteriorated and the catalyst is not heated to an appropriate temperature within a predetermined time.

Hereinafter, the abnormality determination method according to the embodiment will be specifically described with reference to FIG. As shown in FIG. 1, in the abnormality determination method according to the embodiment, the abnormality determination device 1 first acquires the operating state of the engine 101 immediately before the vehicle stops (step S1).

The operating state referred to here is an operating state of the engine 101, for example, the rotation speed of the engine 101, the load factor of the engine 101, and the like. The load factor of the engine 101 is the maximum cylinder when the intake amount per cycle of one cylinder is the cylinder inflow air amount and the cylinder inflow air amount when the throttle opening is the maximum opening is the maximum cylinder inflow air amount. It can be calculated as the ratio of the amount of inflowing air to the cylinder to the amount of inflowing air.

Further, the vehicle stop referred to here refers to a stop in the start-stop system, a so-called idling stop. That is, in the abnormality determination method according to the embodiment, the operating state of the engine 101 in a predetermined period immediately before the idling stop is performed is acquired.

Subsequently, it is assumed that the stopped engine 101 has started (step S2). Then, at the time of starting the engine 101, in the abnormality determination method according to the embodiment, the amount of heat possessed by the A / F sensor 106 is estimated based on the acquired operating state (step S3). Specifically, the abnormality determination device 1 determines the amount of heat at the time of starting the A / F sensor 106 based on the amount of heat of the A / F sensor 106 at the initial stage of stop based on the operating state and the elapsed time from the stop to the start. presume. The calorific value of the A / F sensor 106 is estimated based on the calorific value information (see FIG. 3A) described later, and details of this point will be described later.

Subsequently, in the abnormality determination method according to the embodiment, the required time required for the A / F sensor 106 to be activated is calculated based on the estimated amount of heat at the start of the A / F sensor 106 (step S4). ..

“The A / F sensor 106 is activated” refers to a state in which the detected value (air-fuel ratio) becomes a normal value when the A / F sensor 106 is heated to an appropriate temperature. That is, the required time is the time required to heat the A / F sensor 106 to an appropriate temperature using the exhaust gas warmed by passing through the heated purification catalyst (EHC102a) as a heat medium. The required time is calculated based on the map information (see FIG. 3B) described later, and the details of this point will be described later.

Subsequently, in the abnormality determination method according to the embodiment, the presence or absence of an abnormality related to heating of the purification catalyst EHC102a is determined based on the calculated required time (step S5).

Specifically, in the abnormality determination method according to the embodiment, when the detection value of the A / F sensor 106 after the lapse of the required time is equal to or higher than a predetermined threshold value (that is, a normal value), the abnormality determination device 1 A / Assuming that the F sensor 106 is heated to an appropriate temperature, it is determined that the heating of the EHC 102a is normal. That is, the abnormality determination device 1 determines that there is no abnormality (not deteriorated) in the EHC102a.

On the other hand, when the detection value of the A / F sensor 106 after the required time elapses is less than a predetermined threshold value (that is, an abnormal value), the abnormality determination device 1 assumes that the A / F sensor 106 has not been heated to an appropriate temperature. , It is determined that the heating of EHC102a is abnormal. That is, the abnormality determination device 1 determines that the EHC102a is abnormal (deteriorated).

That is, in the abnormality determination method according to the embodiment, the abnormality determination of the EHC 102a can be performed at the optimum timing by changing the determination timing of the abnormality determination according to the required time. As a result, it is possible to avoid erroneous determination due to erroneous determination timing. Therefore, according to the abnormality determination method according to the embodiment, the abnormality of the EHC 102a can be determined with high accuracy.

Further, if the determination timing is set to a fixed time, a relatively long time is often set in order to ensure the determination accuracy. In this respect, in the abnormality determination method according to the embodiment, the determination timing can be optimized by making the determination timing of the abnormality determination variable according to the required time, so that the determination accuracy is higher than that in the case where the determination timing is set to a fixed time. The judgment timing can be accelerated while ensuring the above.

In the abnormality determination method according to the embodiment, the determination timing can be set after the lapse of a total time obtained by adding a predetermined additional time to the required time, and details of this point will be described later in FIG.

Next, the configuration of the abnormality determination 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 determination device 1 according to the embodiment.

As shown in FIG. 2, the abnormality determination device 1 according to the embodiment is connected to the engine control device 200 and the A / F sensor 106.

The engine control device 200 is a control device that controls the engine 101. The engine control device 200 outputs information regarding the control state (operating state) of the engine 101 to the abnormality determination device 1. Further, the engine control device 200 outputs information regarding the idling stop state (stop and start) to the abnormality determination device 1.

Subsequently, the abnormality determination 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, an estimation unit 22, a calculation unit 23, a determination unit 24, and an update unit 25. The storage unit 3 stores the calorific value information 31 and the map information 32.

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

The CPU of the computer functions as the acquisition unit 21, the estimation unit 22, the calculation unit 23, the determination unit 24, and the update unit 25 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 estimation unit 22, the calculation unit 23, the determination unit 24, and the update unit 25 of the control unit 2 are ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or the like. It can also be configured with the hardware of.

Further, the storage unit 3 corresponds to, for example, a RAM or a flash memory. The RAM or flash memory can store heat quantity information 31, map information 32, information on various programs, and the like. The abnormality determination 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.

Here, the heat quantity information 31 stored in the storage unit 3 is information for estimating the heat quantity possessed by the A / F sensor 106, and is used by the estimation unit 22 described later. FIG. 3A is a diagram showing an example of calorific value information 31.

As shown in FIG. 3A, the calorific value information 31 is two-dimensional graph information in which the vertical axis is "calorific value" and the horizontal axis is "elapsed time". “Heat amount” indicates the amount of heat possessed by the A / F sensor 106. The "elapsed time" indicates the elapsed time from when the engine 101 is stopped to when it is started. The calorific value information 31 is generated based on the results obtained in advance by experiments or the like.

In the example shown in FIG. 3A, the change in the amount of heat according to the elapsed time for each of the three initial amounts of heat A to C is shown. Specifically, the higher the initial calorific value, the higher the rate of decrease in the calorific value according to the elapsed time. The initial calorific value is determined by the operating state, and the higher the rotation speed and the load factor of the engine 101, the higher the initial calorific value. That is, the estimation unit 22, which will be described later, refers to the heat quantity information 31 and estimates the heat quantity at the time of starting the A / F sensor 106 based on the initial heat quantity based on the operating state and the elapsed time until the start.

In FIG. 3A, as an example, three changes in the initial calorific value A to C are shown, but the initial calorific value may be four or more, or two or less.

Subsequently, the map information 32 is information for calculating the required time required for the A / F sensor 106 to be activated, and is used by the calculation unit 23 described later. FIG. 3B is a diagram showing an example of map information 32.

As shown in FIG. 3B, the map information 32 is two-dimensional graph information in which the vertical axis is the “necessary time” and the horizontal axis is the “calorific value”. The "required time" is the required time required for the A / F sensor 106 to be activated. The “heat amount” is the amount of heat at the start of the A / F sensor 106, and is the amount of heat estimated by the estimation unit 22. The map information 32 is generated in advance based on the results by an experiment or the like, and is updated by the update unit 25 described later.

As shown in FIG. 3B, the map information 32 is information showing the relationship between the amount of heat and the required time, and the required time is inversely proportional to the amount of heat. That is, the larger the amount of heat, the shorter the required time. The calculation unit 23, which will be described later, can calculate the required time from the amount of heat estimated by the estimation unit 22 by referring to the map information 32.

Next, each function of the control unit 2 (acquisition unit 21, estimation unit 22, calculation unit 23, determination unit 24, and update unit 25) will be described.

The acquisition unit 21 acquires various types of information. For example, the acquisition unit 21 acquires information regarding the start and stop of the engine 101 from the engine control device 200. Further, when the engine 101 is stopped, the acquisition unit 21 acquires the operating state of the engine 101 immediately before the vehicle is stopped from the engine control device 200.

Specifically, the acquisition unit 21 acquires the operating state in a predetermined period immediately before the stop. For example, the acquisition unit 21 acquires the average value of the rotation speed and the load factor of the engine 101 in a predetermined period immediately before the stop as an operating state. Further, the acquisition unit 21 is not limited to the average value of the rotation speed and the load factor of the engine 101, and may acquire the maximum value of the rotation speed and the load factor of the engine 101 in a predetermined period immediately before the stop as an operating state.

Further, the acquisition unit 21 acquires the air-fuel ratio which is the detected value of the A / F sensor 106.

At the time of starting the vehicle, the estimation unit 22 estimates the amount of heat possessed by the A / F sensor 106 at the time of starting based on the operating state acquired by the acquisition unit 21. Specifically, first, the estimation unit 22 measures the elapsed time from the time when the vehicle is stopped to the time when the vehicle is started.

Subsequently, the estimation unit 22 selects the initial calorific value corresponding to the operating state acquired by the acquisition unit 21 from the calorific value information 31. Then, the estimation unit 22 extracts the calorific value corresponding to the measured elapsed time as the estimation result in the graph corresponding to the selected initial calorific value.

Then, the estimation unit 22 outputs the heat amount information at the time of starting the A / F sensor 106, which is the estimation result, to the calculation unit 23.

The calculation unit 23 calculates the required time required for the A / F sensor 106 to be activated based on the amount of heat at the start of the A / F sensor 106 estimated by the estimation unit 22. Specifically, the calculation unit 23 refers to the map information 32 and outputs the required time corresponding to the amount of heat at the start of the A / F sensor 106 as the calculation result.

The determination unit 24 determines whether or not there is an abnormality related to heating of the A / F sensor 106 based on the required time calculated by the calculation unit 23. Specifically, the determination unit 24 determines the determination timing for performing the abnormality determination based on the calculated required time, and determines the presence or absence of the abnormality at the determined determination timing. Here, the determination process of the determination unit 24 will be described with reference to FIG.

FIG. 4 is a diagram showing the processing contents of the determination unit 24. FIG. 4 shows a timing chart of the control state (start and stop) of the engine 101 and the detected value of the A / F sensor 106. As shown in FIG. 4, it is assumed that the engine 101 is started at time t1.

When the engine 101 is started at time t1, the estimation unit 22 first estimates the amount of heat at the time of starting the A / F sensor 106. Further, the calculation unit 23 determines the required time D1 based on the amount of heat estimated by the estimation unit 22.

Then, the determination unit 24 calculates the total time D3 by adding the predetermined additional time D2 to the required time D1, and determines the time t3 after the lapse of the total time D3 as the determination timing. The determination unit 24 may determine the determination timing at time t2 after the required time D1 has elapsed.

Then, at the time t3, which is the determination timing, the determination unit 24 determines whether or not there is an abnormality in the EHC 102a based on the detection value of the A / F sensor 106. Specifically, the determination unit 24 determines that the EHC 102a is normal when the detected value at time t3 is equal to or greater than a predetermined threshold value TH (solid line in FIG. 4). The threshold value TH is a value preset by the A / F sensor 106.

Specifically, if the detected value is a normal value at time t3, the determination unit 24 is located upstream of the A / F sensor 106 because the A / F sensor 106 is normally heated and activated. It is determined that the heating of the EHC102a is also normal. In other words, the determination unit 24 determines that the EHC102a has not deteriorated.

On the other hand, when the detected value at the time t3 is less than the predetermined threshold value TH (broken line in FIG. 4), the determination unit 24 determines that the EHC 102a is abnormal.

Specifically, if the detected value is an abnormal value at time t3, the determination unit 24 has not activated the A / F sensor 106 because it has not been heated to an appropriate temperature, so that the A / F sensor 106 has not been activated. It is determined that the heating of the EHC102a located upstream is abnormal. In other words, the determination unit 24 determines that the EHC102a, which is the cause of the heating delay, has deteriorated.

In this way, the determination unit 24 can perform the abnormality determination at the optimum determination timing by making the determination timing variable according to the required time D1. That is, the determination accuracy of the abnormality determination can be improved.

Further, the determination unit 24 can improve the stability of the determination result while maintaining the determination accuracy as collateral by setting the total time D3, which is the required time D1 plus the predetermined additional time D2, as the determination timing.

The addition time D2 may be a fixed value or may be made variable according to the required time D1. For example, the addition time D2 may be proportional to the required time D1 or may be inversely proportional to the required time D1.

Returning to FIG. 2, the update unit 25 will be described. The update unit 25 updates the map information 32 based on the real time until the detected value of the A / F sensor 106 reaches the threshold value TH (see FIG. 4). Here, the processing content of the update unit 25 will be described with reference to FIG.

FIG. 5 is a diagram showing the processing contents of the update unit 25. FIG. 5 shows the detected values when the A / F sensor 106 is normally activated.

As shown in FIG. 5, it is assumed that the detected value of the A / F sensor 106 reaches the threshold value TH at time t2b. In such a case, the update unit 25 measures the time from the time t1 to the time t2b as the real time D4.

Then, the update unit 25 updates the map information 32 based on the real time D4. Specifically, the update unit 25 updates the map information 32 when the difference (time difference) between the real time D4 and the required time D1 is equal to or greater than a predetermined value. Specifically, the corresponding required time D1 in the map information 32 is replaced with the real time D4. Alternatively, the update unit 25 may correct the required time D1 based on the real time D4. For example, the update unit 25 makes a correction to replace the required time D1 with the average value of the real time D4.

That is, when the deviation between the real time D4 and the required time D1 which is the experimental value is equal to or more than a predetermined value, the updating unit 25 updates the map information 32 to obtain the accuracy of the required time D1 calculated thereafter. Can be enhanced.

The update unit 25 performs the update process only when the determination unit 24 determines that the EHC102a is normal, and prohibits the update process when the determination unit 24 determines that the EHC102a is abnormal.

Next, the processing procedure of the processing executed by the abnormality determination device 1 according to the embodiment will be described with reference to FIGS. 6 to 8. FIG. 6 is a flowchart showing a processing procedure of the entire processing executed by the abnormality determination device 1 according to the embodiment. FIG. 7 is a flowchart showing a processing procedure of the abnormality determination process executed by the abnormality determination device 1 according to the embodiment. FIG. 8 is a flowchart showing a processing procedure of the update process executed by the abnormality determination device 1 according to the embodiment.

First, the processing procedure of the entire processing will be described with reference to FIG.

As shown in FIG. 6, the acquisition unit 21 determines idling stop, that is, whether or not the vehicle has stopped (step S101), and if idling stop is not performed (step S101: No), step S101 until idling stop is performed. Is repeated.

When the vehicle stops idling (step S101: Yes), the acquisition unit 21 acquires the operating state of the engine 101 immediately before the stop (step S102).

Subsequently, the acquisition unit 21 determines whether or not the engine 101 has started (step S103), and if the engine 101 has not started (step S103: No), repeats step S103 until the engine 101 starts. do.

When the engine 101 is started (step S103: Yes), the estimation unit 22 estimates the amount of heat possessed by the A / F sensor 106 at the time of starting the engine 101 based on the acquired operating state (step S104).

Subsequently, the calculation unit 23 calculates the required time required for the A / F sensor 106 to be activated based on the estimated amount of heat (step S105).

Subsequently, the determination unit 24 determines an abnormality related to heating of the purification catalyst EHC102a based on the calculated required time (step S106), and ends the process.

Next, the processing procedure of the abnormality determination process will be described with reference to FIG. 7.

As shown in FIG. 7, the determination unit 24 determines whether or not the total time D3 has elapsed since the engine 101 was started (step S201), and when the total time D3 has not elapsed (step S201: No). ), Step S201 is repeatedly executed until the total time D3 elapses.

When the total time D3 has elapsed (step S201: Yes), the determination unit 24 acquires the detected value of the A / F sensor 106, which is the air-fuel ratio sensor after the total time D3 has elapsed (step S202).

Subsequently, the determination unit 24 determines whether or not the acquired detection value is equal to or greater than a predetermined threshold value TH (step S203).

When the detection value is equal to or higher than the threshold value TH (step S203: Yes), the determination unit 24 determines that the purification catalyst EHC102a is normal, that is, the EHC102a is normally heated (step S204), and ends the process. do.

On the other hand, when the detected value is less than the threshold value TH (step S203: No), the determination unit 24 determines that the EHC102a is abnormal, that is, the EHC102a cannot be heated normally (step S205), and ends the process.

Next, the processing procedure of the update process will be described with reference to FIG.

First, it is assumed that the engine 101 is started (step S301).

Subsequently, the update unit 25 acquires the detected value of the A / F sensor 106 after the engine 101 is started, and determines whether or not the acquired detected value has reached the threshold value TH (step S302).

When the detection value has not reached the threshold value TH (step S302: No), the update unit 25 repeatedly executes step S302 until the detection value reaches the threshold value TH.

Subsequently, the update unit 25 acquires the real-time D4 that has elapsed from the start of the engine 101 until the detected value reaches the threshold value TH (step S303).

Subsequently, the update unit 25 determines whether or not the difference (time difference) between the real time D4 and the required time D1 is equal to or greater than a predetermined value (step S304).

Subsequently, when the difference is equal to or greater than a predetermined value (step S304: Yes), the update unit 25 updates the map information 32 based on the real time D4 (step S305), and ends the process.

On the other hand, when the difference is less than a predetermined value (step S304: No), the update unit 25 ends the process without updating the map information 32.

As described above, the abnormality determination device 1 according to the embodiment includes an acquisition unit 21, an estimation unit 22, a calculation unit 23, and a determination unit 24. The acquisition unit 21 acquires the operating state of the internal combustion engine (engine 101) immediately before the vehicle stops. At the time of starting the vehicle, the estimation unit 22 purifies the exhaust gas G purified by the purification catalyst (EHC102a) that purifies the exhaust gas G of the engine 101 by heating with a heater based on the operating state acquired by the acquisition unit 21. The amount of heat of the air-fuel ratio sensor (A / F sensor 106) that detects the air-fuel ratio is estimated. The calculation unit 23 calculates the required time D1 required for the A / F sensor 106 to be activated based on the amount of heat at the start of the vehicle estimated by the estimation unit 22. The determination unit 24 determines whether or not there is an abnormality related to heating of the EHC102a based on the required time D1 calculated by the calculation unit 23. Thereby, the abnormality of the catalyst EHC102a can be determined with high accuracy.

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 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 judgment device 2 Control unit 3 Storage unit 21 Acquisition unit 22 Estimate unit 23 Calculation unit 24 Judgment unit 25 Update unit 31 Calorific value information 32 Map information 100 Purification device 101 Engine 102 Catalyst unit 102a EHC
102b Rr catalyst 103 Power supply 104 Underfloor catalyst 105 Exhaust heat recovery device 106 A / F sensor 107 Exhaust path 200 Engine control device G Exhaust gas S Abnormality judgment system D1 Required time D2 Addition time D3 Total time D4 Real time

Claims (6)

An acquisition unit that acquires the operating state of the internal combustion engine immediately before the vehicle stops,
At the time of starting the vehicle, based on the operating state acquired by the acquisition unit, the air-fuel ratio of the exhaust gas purified by the purification catalyst that purifies the exhaust gas of the internal combustion engine by heating with a heater is detected. An estimation unit that estimates the amount of heat of the fuel ratio sensor,
A calculation unit that calculates the time required for the air-fuel ratio sensor to be activated based on the amount of heat at the time of starting the vehicle estimated by the estimation unit.
An abnormality determination device including a determination unit for determining the presence or absence of an abnormality related to heating of the purification catalyst based on the required time calculated by the calculation unit. The determination unit
When the detected value of the air-fuel ratio sensor is less than a predetermined threshold value when the total time obtained by adding a predetermined additional time to the required time elapses, the claim is characterized in that the purification catalyst is determined to be abnormal. Item 1. The abnormality determination device according to item 1. A storage unit that stores map information indicating the relationship between the calorific value and the required time.
Further, an update unit for updating the map information based on the real time until the detected value of the air-fuel ratio sensor reaches the predetermined threshold value is provided.
The calculation unit
The abnormality determination device according to claim 2, wherein the required time is calculated based on the map information updated by the update unit. The acquisition unit
The abnormality determination device according to any one of claims 1 to 3, wherein the rotation speed of the internal combustion engine and the load factor of the internal combustion engine are acquired as the operating state. The vehicle
The abnormality determination device according to any one of claims 1 to 4, wherein the vehicle is a vehicle whose drive source is a motor driven by electric power generated by the internal combustion engine. The acquisition process to acquire the operating state of the internal combustion engine immediately before the vehicle stops,
At the time of starting the vehicle, the air-fuel ratio of the exhaust gas purified by the purification catalyst that purifies the exhaust gas of the internal combustion engine by heating with a heater is detected based on the operating state acquired by the acquisition process. The estimation process for estimating the amount of heat of the fuel ratio sensor and
A calculation step of calculating the time required for the air-fuel ratio sensor to be activated based on the amount of heat at the time of starting the vehicle estimated by the estimation step, and a calculation step.
An abnormality determination method including a determination step of determining the presence or absence of an abnormality related to heating of the purification catalyst based on the required time calculated by the calculation step.

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