JP2018178775A - Filter regeneration control device and filter regeneration control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the execution of filter regeneration at a proper timing considering passive regeneration.SOLUTION: An ECU 7 includes an instruction output part 110 for instructing a fuel injection device 6 to execute fuel injection when a travel distance of a vehicle reaches a filter regeneration threshold value, a heat rate calculation part 120 for calculating the heat rate of a DOC 8 provided on the upstream side of a DPF 9 when predetermined conditions are satisfied, a combustion amount estimation part 130 for estimating the combustion amount of PMs on the basis of the calculated heat rate, and a threshold value extension part 140 for extending a filter regeneration threshold value on the basis of the estimated combustion amount of the PMs.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a filter regeneration control device and a filter regeneration control method for controlling regeneration of a filter that collects particulate matter in exhaust gas.

  DESCRIPTION OF RELATED ART Conventionally, DPF (Diesel particulate filter) which collects the particulate matter (Particulate Matter: Hereinafter, it is called PM) contained in the exhaust gas of a diesel engine is known (for example, refer patent document 1).

  Of the PM collected by the DPF, a part is burned by the high temperature exhaust gas emitted from the diesel engine (referred to as passive regeneration or continuous regeneration), and the remainder is deposited in the DPF. Then, if the deposition amount of PM exceeds a certain amount, for example, a decrease in the output of a diesel engine, a decrease in fuel efficiency, and damage to the DPF due to abnormal combustion of PM and the like occur.

  Therefore, it is known to execute filter regeneration (also referred to as forced regeneration) in which the filter is regenerated by forcibly burning PM accumulated in the DPF by post injection or exhaust pipe injection.

JP 2005-54631 A

  The filter regeneration described above is performed, for example, when the travel distance of the vehicle reaches a preset threshold (hereinafter, referred to as a filter regeneration threshold). However, even if the traveling distance is the same, the PM deposition amount when the high load operation continues is smaller than the PM deposition amount when the low load operation continues. This is because when the high load operation continues, the above-described passive regeneration is performed.

  Therefore, when high load operation continues, there is a problem that filter regeneration is performed at an inappropriate timing.

  An object of the present invention is to provide a filter regeneration control device and a filter regeneration control method capable of executing filter regeneration at an appropriate timing considering passive regeneration.

  The filter regeneration control device according to the present invention is a filter regeneration control device that controls execution of filter regeneration that forcibly regenerates a filter that collects PM contained in an exhaust gas of an internal combustion engine of a vehicle. The heat generation rate of the catalyst provided on the upstream side of the filter when the predetermined condition is satisfied, and the instruction output unit that instructs the fuel injection device to execute the fuel injection when the first filter regeneration threshold is reached. The first filter regeneration based on the estimated combustion amount of the PM, and the combustion amount estimation unit for estimating the combustion amount of the PM based on the calculated heat ratio; And a threshold extension that extends the threshold.

  The filter regeneration control method according to the present invention is a filter regeneration control method for controlling execution of filter regeneration that forcibly regenerates a filter that collects PM contained in exhaust gas of an internal combustion engine of a vehicle. Calculating the heat generation rate of the catalyst provided on the upstream side of the filter, and estimating the combustion amount of the PM based on the calculated heat generation rate, and the combustion of the PM estimated. Extending the first filter regeneration threshold based on an amount, and instructing the fuel injector to perform fuel injection if the travel distance of the vehicle reaches the first filter regeneration threshold; Have.

  According to the present invention, filter regeneration can be performed at an appropriate timing in consideration of passive regeneration.

Post-processing apparatus according to an embodiment of the present invention and a conceptual diagram showing an example of its peripheral configuration Block diagram showing a configuration example of the ECU according to the embodiment of the present invention Flow chart showing an operation example of the ECU according to the embodiment of the present invention The figure which shows an example of the filter regeneration threshold value and the diagnostic threshold value which concern on the modification of this invention. The figure which shows the example of a change of the filter regeneration threshold concerning the modification of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, the post-processing apparatus according to the embodiment of the present invention and the peripheral configuration thereof will be described with reference to FIG.

  FIG. 1 is a conceptual view showing an example of the post-processing apparatus according to the present embodiment and its peripheral configuration. In FIG. 1, solid and straight arrows indicate the flow of gas, and broken arrows indicate the flow of signal.

  Each component shown in FIG. 1 is mounted on, for example, a vehicle.

  An intake passage 2 is connected to the upstream side of a diesel engine (an example of an internal combustion engine; hereinafter referred to as an engine) 1, and an exhaust passage 3 is connected to the downstream side of the engine 1.

  A turbocharger (supercharger) 4 is provided between the air supply passage 2 and the exhaust passage 3. The turbocharger 4 has a compressor 4 a disposed in the air supply passage 2 and an exhaust turbine 4 b disposed in the exhaust passage 3. The compressor 4a is coaxially driven by the exhaust turbine 4b.

  An intercooler 5 is provided in the air supply passage 2. The air discharged from the compressor 4 a is cooled by the intercooler 5 and flows into a combustion chamber (not shown) in each cylinder (not shown) of the engine 1.

  The engine 1 is provided with a common rail fuel injection device (hereinafter referred to as a fuel injection device) 6 that injects fuel into a combustion chamber in each cylinder. The fuel injection device 6 is controlled based on a control signal from the ECU 7 so that a predetermined amount of fuel is supplied from the common rail 6a to the fuel injection valve 6b at a predetermined timing. The details of the ECU 7 will be described later with reference to FIG.

  The exhaust passage 3 is provided with an oxidation catalyst (referred to as DOC hereinafter) 8 and a DPF 9 as a post-treatment device. The DOC 8 is provided on the upstream side of the DPF 9.

DOC 8 oxidizes and removes hydrocarbons (HC) and carbon monoxide (CO) in the exhaust gas, and oxidizes nitrogen monoxide (NO) in the exhaust gas to produce nitrogen dioxide (NO ₂ ).

  As described above, the DPF 9 collects PM such as soot contained in the exhaust gas and removes it from the exhaust gas.

  The exhaust gas discharged from the engine 1 passes through the exhaust passage 3 and drives the exhaust turbine 4b to coaxially drive the compressor 4a. Thereafter, the exhaust gas flows in the order of DOC 8 and DPF 9.

  The exhaust passage 3 is provided with an inlet temperature sensor 10 for detecting the temperature of the inlet of the DOC 8 and an outlet temperature sensor 11 for detecting the temperature of the outlet of the DOC 8 (in other words, the inlet of the DPF 9). The inlet temperature sensor 10 and the outlet temperature sensor 11 appropriately output a signal indicating the detected temperature to the ECU 7.

  The post-processing apparatus according to the present embodiment and the configuration around it have been described above.

  Next, the configuration of the ECU 7 (an example of the filter regeneration control device) according to the present embodiment will be described with reference to FIG.

  The ECU 7 includes, for example, a central processing unit (CPU), a storage medium such as a read only memory (ROM) storing a control program, a working memory such as a random access memory (RAM), and a communication circuit. The functions of the units in FIG. 2 described below are realized by the CPU executing a control program.

  The ECU 7 controls the execution of the filter regeneration that forcibly regenerates the DPF 9. Specifically, the ECU 7 controls the execution of fuel injection (for example, post injection) of the fuel injection device 6.

  As shown in FIG. 2, the ECU 7 includes an instruction output unit 110, a heat generation rate calculation unit 120, a combustion amount estimation unit 130, and a threshold value extension unit 140.

  When the actual travel distance of the vehicle reaches the filter regeneration threshold, instruction output unit 110 outputs a control signal instructing fuel injection device 6 to execute fuel injection (in other words, filter regeneration). The fuel injection device 6 having received this control signal executes fuel injection. The above "actual travel distance of the vehicle" is the travel distance from the time when the previous filter regeneration is completed.

  The filter regeneration threshold value (an example of a first filter regeneration threshold value) is a value indicating a travel distance to execute filter regeneration. The filter regeneration threshold is set to a default value (which may be reworded as a reference value), and this default value may be extended by a threshold extension unit 140 described later.

  The control signal output to the fuel injection device 6 includes an instruction of the fuel injection amount. For example, the instruction output unit 110 can calculate the injection amount of fuel based on input signals from various sensors such as a crank sensor, a cam sensor, an accelerator sensor, a throttle sensor, and a coolant temperature sensor (all not shown). . Since the process of calculating the injection amount is known, the detailed description thereof will be omitted.

  The heat generation rate calculation unit 120 determines whether the engine 1 has a high output. For example, first, the heat generation rate calculation unit 120 calculates the current output value of the engine 1 (engine torque × engine rotation speed. Hereinafter, referred to as engine output value). Since this calculation method is a known technique, the description will be omitted. Next, the heat generation rate calculation unit 120 determines whether the calculated engine output value is equal to or greater than a predetermined threshold. The threshold is a value set based on a previously performed experiment or simulation, and can be determined whether the engine 1 has a high output. Then, if the calculated engine output value is equal to or greater than the threshold value, the heat generation rate calculation unit 120 determines that the engine 1 has a high output. Note that the process of determining whether or not the engine 1 has high output is not limited to the method described above, and other methods may be used.

Then, when it is determined that the engine 1 has high output (an example when the predetermined condition is satisfied), the heat generation rate calculation unit 120 calculates the hydrocarbon heat generation rate of the DOC 8 (hereinafter referred to as DOC heat generation rate). This DOC heat release rate can be calculated, for example, by the following equation.
DOC heat generation rate = (hydrocarbon heat generation amount in DOC 8) / (theoretical heat generation amount at the time of fuel injection)

  The theoretical calorific value shown in the above equation is a value known to the ECU 7. On the other hand, the hydrocarbon calorific value shown in the above-mentioned formula is specified as follows, for example.

  First, the heat generation rate calculation unit 120 calculates a temperature difference between the temperature detected by the inlet temperature sensor 10 and the temperature detected by the outlet temperature sensor 11. Next, the heat generation rate calculation unit 120 is configured to associate the first reference data (for example, the temperature difference and the heat generation amount) in which the heat generation amount is predetermined for each temperature difference from a predetermined storage unit (not shown). Read a map or table). Then, the heat generation rate calculation unit 120 specifies the heat generation amount corresponding to the calculated temperature difference from the first reference data.

  The combustion amount estimation unit 130 estimates the combustion amount of PM (in other words, the filter regeneration amount by passive regeneration) based on the DOC heat release rate calculated by the heat release rate calculation unit 120. This estimation process is performed, for example, as follows.

  First, the combustion amount estimation unit 130 uses a predetermined storage unit (not shown) to generate second reference data (for example, the DOC heat generation rate and the PM combustion amount) in which the combustion amount of PM is determined for each DOC heat release rate. Read out the map or table etc. Then, the combustion amount estimation unit 130 specifies the combustion amount of PM corresponding to the DOC heat release rate calculated by the heat release rate calculation unit 120 from the second reference data.

  The combustion amount estimation unit 130 converts the estimated (specified) combustion amount of PM into a travel distance. This conversion process is performed, for example, as follows.

  First, the combustion amount estimation unit 130 determines, from a predetermined storage unit (not shown), third reference data (for example, the PM combustion amount and the travel distance correspond to each other) for which the travel distance is determined for each PM combustion amount. Read the attached map or table etc.) Then, the combustion amount estimation unit 130 specifies the travel distance corresponding to the estimated combustion amount of PM from the third reference data.

  The travel distance converted in this manner is a value larger than the filter regeneration threshold value (for example, default value) being set.

  The threshold extension unit 140 extends the filter regeneration threshold based on the converted (specified) travel distance. For example, the threshold extension unit 140 changes the filter regeneration threshold (for example, default value) being set to the converted travel distance. That is, the converted travel distance is used as a new filter regeneration threshold.

  Note that the first to third reference data described above are data generated based on the results of experiments and simulations performed in advance.

  In addition, storage units that store the first to third reference data may be mounted on the vehicle or may be installed outside the vehicle. In the latter case, the ECU 7 acquires first to third reference data by wireless communication via a predetermined network.

  Moreover, the method of the process which the heat release rate calculation part 120, the combustion amount estimation part 130, and the threshold value extension part 140 perform is not limited to the said description.

  The configuration of the ECU 7 according to the present embodiment has been described above.

  Next, the operation of the ECU 7 (an example of the filter regeneration control method) according to the present embodiment will be described with reference to FIG.

  First, the heat generation rate calculation unit 120 calculates the DOC heat generation rate at the time of high output of the engine 1 (step S101).

  Next, the combustion amount estimation unit 130 estimates the combustion amount of PM based on the DOC heat release rate calculated in step S101 (step S102).

  Next, the combustion amount estimation unit 130 converts the combustion amount of PM estimated in step S102 into a travel distance (step S103).

  Next, the threshold extension unit 140 extends the filter regeneration threshold based on the travel distance converted in step S104 (step S104).

  Then, when the actual travel distance of the vehicle reaches the extended filter regeneration threshold, the instruction output unit 110 instructs the fuel injection device 6 to execute the fuel injection by outputting the control signal (step S105). . Thus, the fuel injection device 6 executes fuel injection, and filter regeneration is realized.

  The flow of FIG. 3 described above is repeated while the vehicle is traveling. That is, in the present embodiment, while the vehicle is traveling, the filter regeneration threshold is extended each time the engine 1 has a high output (in other words, the filter regeneration threshold is continuously varied).

  The operation of the ECU 7 according to the present embodiment has been described above.

  As described in detail, according to the present embodiment, the heat generation rate of the DOC 8 at the time of the high output of the engine 1 is calculated, the PM combustion amount is estimated based on the calculated heat generation rate, and the estimated PM The present invention is characterized in that the amount of combustion of is converted into a travel distance, and the filter regeneration threshold is extended based on the converted travel distance. Thereby, filter regeneration can be performed at an appropriate timing in consideration of passive regeneration.

  As mentioned above, although the embodiment of the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and may be appropriately modified and implemented without departing from the scope of the present invention. It is possible. Each modification will be described below.

[Modification 1]
For example, in addition to the filter regeneration threshold, a diagnosis threshold larger than the filter regeneration threshold may be set. The diagnosis threshold value is a value indicating a travel distance to which a notification (hereinafter referred to as a notification) to urge the vehicle occupant to inspect or repair the DPF 9 (which may be referred to as warehousing to a dealer) may be performed. As with the filter regeneration threshold, a default value (which may be restated as a reference value) is also set for this diagnostic threshold.

  When the actual travel distance of the vehicle reaches the diagnosis threshold after the filter regeneration is performed, the instruction output unit 110 instructs the notification unit (not shown, for example, a lamp, a display, etc.) to execute notification. The notification unit that has received this instruction executes notification. Thereby, the occupant of the vehicle can recognize that it is necessary to inspect or repair the DPF 9 (carry-in to the dealer).

  Also, when extending the filter regeneration threshold, the threshold extension unit 140 may also extend the diagnostic threshold (for example, default value).

[Modification 2]
For example, the filter regeneration threshold and the diagnosis threshold described above may be set to indicate a differential pressure on the upstream side and the downstream side of the DPF 9 (hereinafter referred to as DPF differential pressure) in addition to the one indicating the travel distance.

  This example is shown in FIG. The vertical axis in FIG. 4 indicates the DPF differential pressure, and the horizontal axis in FIG. 4 indicates the travel distance.

  In FIG. 4, TH1 is a filter regeneration threshold (an example of a first filter regeneration threshold) indicating the traveling distance for which filter regeneration is to be performed as described in the above embodiment, and TH2 is described in the first modification. It is a diagnostic threshold value which shows the run distance which should perform information.

  Further, in FIG. 4, TH3 is a filter regeneration threshold (one example of a second filter regeneration threshold) indicating the DPF differential pressure at which filter regeneration should be performed, and TH4 is a diagnosis indicating the DPF differential pressure at which notification should be performed. It is a threshold.

  As shown in FIG. 4, when four threshold values are set, the instruction output unit 110 sets the fuel injection device 6 when the actual travel distance reaches TH1 or when the DPF differential pressure reaches TH3. Direct the execution of fuel injection to The DPF differential pressure is detected by a differential pressure sensor (not shown) that detects the DPF differential pressure. The differential pressure sensor appropriately outputs a signal indicating the DPF differential pressure to the ECU 7.

  In addition, the instruction output unit 110 instructs the notification unit to execute notification when the actual travel distance reaches TH2 or when the DPF differential pressure reaches TH4.

  And when extending TH1, threshold extension part 140 may change so that TH3 may fall gradually.

  This example is shown in FIG. The vertical axis in FIG. 5 indicates the DPF differential pressure, and the horizontal axis in FIG. 5 indicates the travel distance. Moreover, in FIG. 5, TH1 'has shown the filter regeneration threshold value which extended TH1.

  As shown in FIG. 5, when the TH1 is changed to TH1 ′, the threshold extension unit 140 changes the TH3 to gradually decrease as shown by a slope straight line A in the drawing.

  Alternatively, when the travel distance of the vehicle reaches TH1 before the extension, the threshold extension portion 140 may be changed so that TH3 gradually decreases as shown by the inclined straight line B in the figure.

  In FIG. 5, as an example, the decrease in TH3 is indicated by the inclined straight lines A and B, but is not limited to the straight line. Also, the size of the inclination is not limited to the size shown in FIG.

[Modification 3]
In the above embodiment, the post injection by the common rail fuel injection device 6 has been described as an example, but the present invention is not limited to this. For example, fuel injection (so-called exhaust pipe injection) may be performed using an injection device (not shown) provided in the exhaust passage 3 separately from the common rail fuel injection device 6.

[Modification 4]
Although the case where the filter regeneration threshold value is continuously varied has been described as an example in the above embodiment, the present invention is not limited to this. For example, the filter regeneration threshold may be discretely varied.

  For example, the combustion amount estimation unit 130 estimates the PM combustion amount (or the travel distance converted from the PM combustion amount) based on the heat generation rate from the time when the previous filter regeneration is completed, and the threshold extending unit 140 The filter regeneration threshold may be extended when the accumulated value of the estimated PM combustion amount (or the travel distance converted from the PM combustion amount) exceeds a certain value.

[Modification 5]
Although the heat generation rate calculation unit 120 described the case where the DOC heat generation rate is calculated when the engine 1 has a high output in the above embodiment, the present invention is not limited to this.

  For example, if the temperature of the exhaust gas in the exhaust passage 3 (for example, the temperature detected by the inlet temperature sensor 10) is equal to or higher than a predetermined threshold (the predetermined condition is satisfied) One example) DOC heat release rate may be calculated.

[Modification 6]
In the above embodiment, the combustion amount estimation unit 130 estimates the combustion amount of PM, converts the combustion amount of PM into a travel distance, and the threshold value extension unit 140 performs filter regeneration based on the converted travel distance. Although the case of extending the threshold has been described as an example, the present invention is not limited to this.

  For example, the combustion amount estimation unit 130 may estimate the PM combustion amount, and the threshold extension unit 140 may extend the filter regeneration threshold based on the estimated PM combustion amount.

  The modification has been described above.

<Summary of this disclosure>
The filter regeneration control device according to the present invention is a filter regeneration control device that controls execution of filter regeneration that forcibly regenerates a filter that collects PM contained in an exhaust gas of an internal combustion engine of a vehicle. When the engine reaches the first filter regeneration threshold, the instruction output unit instructs the fuel injection device to execute the fuel injection, and when the internal combustion engine has a high output, the heat generation of the catalyst provided on the upstream side of the filter A heat generation rate calculation unit for calculating the fuel consumption rate, a combustion amount estimation unit for estimating the combustion amount of the PM based on the calculated heat generation rate, and converting the estimated combustion amount of the PM into travel distance; And a threshold extending unit that extends the first filter regeneration threshold based on the travel distance.

  In the filter regeneration control device, the heat generation rate calculation unit satisfies the predetermined condition when the output value of the internal combustion engine is equal to or higher than a predetermined threshold or when the temperature of the exhaust gas is equal to or higher than a predetermined threshold. It may be determined that the

  Further, in the filter regeneration control device, the combustion amount estimation unit converts the estimated combustion amount of PM into a travel distance, and the threshold value extension unit performs the first calculation based on the converted travel distance. The filter regeneration threshold of may be extended.

  Further, in the filter regeneration control device, the instruction output unit is informed that the inspection or the repair of the filter is urged when the travel distance of the vehicle reaches a diagnosis threshold larger than the first filter regeneration threshold. When the notification unit is instructed to execute, and the threshold extension unit extends the first filter regeneration threshold, the diagnosis threshold may also be extended.

  In the filter regeneration control device, the instruction output unit instructs the fuel injection device to execute fuel injection when the differential pressure on the upstream side and the downstream side of the filter reaches a second filter regeneration threshold. The threshold extension unit may change the second filter regeneration threshold to gradually decrease when the first filter regeneration threshold is extended.

  In the filter regeneration control device, the second filter regeneration threshold is gradually decreased when the travel distance of the vehicle reaches the first filter regeneration threshold before the vehicle travel distance reaches the first filter regeneration threshold. You may change it.

  In the filter regeneration control device, the filter may be a DPF, and the catalyst may be an oxidation catalyst.

  The filter regeneration control method of the present invention is a filter regeneration control method for controlling execution of filter regeneration that forcibly regenerates a filter that collects PM contained in exhaust gas of an internal combustion engine of a vehicle, wherein the internal combustion engine is high. If it is an output, the step of calculating the heat generation rate of the catalyst provided on the upstream side of the filter, and the combustion amount of the PM estimated based on the calculated heat generation rate, the combustion amount of the PM estimated. Converting the first filter regeneration threshold based on the converted travel distance, and when the travel distance of the vehicle reaches the first filter regeneration threshold, And b. Instructing the fuel injection device to execute fuel injection.

  The present invention is applicable to a filter regeneration control device and a filter regeneration control method for controlling forced regeneration of a filter that collects PM contained in exhaust gas.

1 Diesel engine (an example of an internal combustion engine)
Reference Signs List 2 air supply passage 3 exhaust passage 4 turbocharger 4a compressor 4b exhaust turbine 5 intercooler 6 fuel injection device 6a common rail 6b fuel injection valve (example of filter regeneration control device)
7 ECU
8 DOC (example of catalyst)
9 DPF (example of filter)
10 inlet temperature sensor 11 outlet temperature sensor 110 instruction output unit 120 heat generation rate calculation unit 130 combustion amount estimation unit 140 threshold extension unit

Claims (8)

A filter regeneration control device that controls execution of filter regeneration that forcibly regenerates a filter that collects PM contained in an exhaust gas of an internal combustion engine of a vehicle.
An instruction output unit for instructing the fuel injection device to execute fuel injection when the travel distance of the vehicle reaches a first filter regeneration threshold;
A heat generation rate calculation unit that calculates a heat generation rate of a catalyst provided on the upstream side of the filter when a predetermined condition is satisfied;
A combustion amount estimation unit configured to estimate the combustion amount of the PM based on the calculated heat release rate;
And a threshold extending unit that extends the first filter regeneration threshold based on the estimated PM combustion amount.
Filter regeneration control device. The heat generation rate calculation unit
When the output value of the internal combustion engine is equal to or higher than a predetermined threshold value, or when the temperature of the exhaust gas is equal to or higher than a predetermined threshold value, it is determined that the predetermined condition is satisfied.
The filter regeneration control device according to claim 1. The combustion amount estimation unit
Convert the estimated amount of combustion of PM into travel distance,
The threshold extension unit
Extending the first filter regeneration threshold based on the converted travel distance;
The filter regeneration control device according to claim 1. The instruction output unit is
When the travel distance of the vehicle reaches a diagnosis threshold larger than the first filter regeneration threshold, the notification unit is instructed to execute notification to prompt inspection or repair of the filter,
The threshold extension unit
The diagnostic threshold is also extended if the first filter regeneration threshold is extended,
The filter regeneration control device according to any one of claims 1 to 3. The instruction output unit is
When the differential pressure on the upstream side and the downstream side of the filter reaches a second filter regeneration threshold, the fuel injection device is instructed to execute fuel injection,
The threshold extension unit
When extending the first filter regeneration threshold, the second filter regeneration threshold is changed so as to gradually decrease.
The filter regeneration control device according to any one of claims 1 to 4. The threshold extension unit
When the travel distance of the vehicle reaches the first filter regeneration threshold before extension, the second filter regeneration threshold is changed so as to gradually decrease.
The filter regeneration control device according to claim 5. The filter is DPF,
The catalyst is an oxidation catalyst,
The filter regeneration control device according to any one of claims 1 to 6. A filter regeneration control method for controlling execution of filter regeneration that forcibly regenerates a filter that collects PM contained in exhaust gas of an internal combustion engine of a vehicle, comprising:
Calculating a heat generation rate of a catalyst provided on the upstream side of the filter when a predetermined condition is satisfied;
Estimating the amount of combustion of the PM based on the calculated heat release rate;
Extending the first filter regeneration threshold based on the estimated amount of combustion of the PM;
Instructing the fuel injection device to execute fuel injection when the travel distance of the vehicle reaches the first filter regeneration threshold.
Filter regeneration control method.

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