JP7431960B2 - Internal combustion engine control device - Google Patents

Description

The present invention relates to an internal combustion engine control device.

In an internal combustion engine, soot is produced as particulate matter when a mixture of fuel and air is combusted. In order to reduce the amount of soot emitted, internal combustion engines are provided with a gasoline particulate filter (hereinafter referred to as "GPF") which is a filter that collects soot. In order to prevent clogging of the GPF, when a predetermined amount of soot has accumulated, a regeneration operation is performed in which the collected soot is burned and removed (incinerated).

FIG. 13 is a time chart showing an operational example of conventional GPF regeneration control.
As shown in FIG. 13, when the temperature of the GPF reaches the regeneration temperature or higher, oxygen is supplied to the GPF by a fuel cut (F/C) executed when the vehicle is decelerated with the accelerator pedal off. Then, the GPF is regenerated by burning the soot. When performing a GPF regeneration operation, the amount of soot deposited on the GPF before regeneration (soot accumulation amount) is estimated, and after the regeneration operation, the amount of incinerated soot and the amount of soot remaining in the GPF are estimated. will be held.

Next, an outline of a conventional method for estimating the amount of soot remaining will be described with reference to FIGS. 14 to 16.
FIG. 14 is a schematic diagram showing a first method in the conventional method for estimating the amount of soot remaining.
The first method shown in FIG. 14 uses a soot accumulation amount estimation logic that estimates the soot accumulation amount, a soot incineration amount estimation logic that estimates the soot incineration amount, and a soot remaining amount estimation logic that estimates the soot remaining amount. configured. The soot accumulation amount estimation logic and soot incineration amount estimation logic estimate the soot accumulation amount and soot incineration amount from logical operations using physical formulas, MAP, etc. In the soot remaining amount estimation logic, the soot remaining amount is estimated by subtracting the estimated soot incineration amount from the estimated soot accumulation amount.

FIGS. 15A to 15C are schematic diagrams showing a second method in the conventional method for estimating the amount of soot remaining.
In the second method, as shown in FIG. 15A, a differential pressure sensor is used to measure the difference in pressure between the upstream side and the downstream side of the GPF (differential pressure). Then, the residual amount of soot is estimated as shown in FIG. 15C from the calibration curve showing the relationship between the differential pressure ΔP and the residual amount of soot shown in FIG. 15B.

Note that, as shown in FIG. 13, in the conventional method of estimating the amount of soot remaining, an error occurs between the estimated value and the actual value. Then, in order to eliminate this error, the estimated value is corrected.
FIG. 16 is a schematic diagram showing a third method in the conventional method for estimating the amount of soot remaining. The third method shown in FIG. 16 corrects the estimated value by combining the first method and the second method described above.

As shown in FIG. 16, the third method uses the second method, that is, the soot residual amount estimated using the GPF differential pressure ΔP, as a reference value (true value), and Calculate the difference from the amount of soot remaining estimated by calculation. Then, the soot accumulation amount estimation logic is corrected using the calculated difference.

As a conventional technique for estimating the amount of soot remaining, for example, there is a technique as described in Patent Document 1. In Patent Document 1, a first estimated amount based on the operating state of the internal combustion engine and a second estimated amount based on the differential pressure before and after the filter are calculated, and the deviation between the first estimated amount and the second estimated amount is calculated. A technique is described in which the amount of soot deposited is corrected using this deviation.

FIGS. 17A to 18B are explanatory diagrams showing errors occurring in the estimated value of the remaining amount of soot based on logical operations. 17A and 17B show errors caused by the soot accumulation amount estimation logic, and FIGS. 18A and 18B show errors caused by the soot incineration amount estimation logic.

In the examples shown in FIGS. 17A and 17B, if an error occurs in the logic for estimating the amount of soot deposited, the estimated amount of soot deposited will be overcalculated, resulting in an estimation error, so there will be an error in the estimated remaining amount of soot after regeneration. arise. At this time, the estimated soot remaining amount calculated from the differential pressure is taken as the true value, and the difference between it and the estimated soot remaining amount calculated by logical operation is calculated. Then, the estimation unit (soot accumulation amount estimation logic) that estimates the estimated soot accumulation amount is corrected based on the calculated difference.

On the other hand, in the examples shown in FIGS. 18A and 18B, if an error occurs in the logic for estimating the amount of soot incinerated, the estimated amount of soot remaining after regeneration is An error occurs in the amount. At this time, the estimated soot remaining amount calculated from the differential pressure is taken as the true value, and the difference between it and the estimated soot remaining amount calculated by logical operation is calculated. In the conventional technology, the calculated difference is an error caused by the amount of soot incinerated, but the estimation unit (the logic for estimating the amount of soot accumulated) that calculates the estimated amount of accumulated soot is corrected.

JP2019-105181A

In addition, errors occurring in the estimated value of the amount of soot remaining by logical operations include not only errors caused by the estimated value of the amount of soot accumulation, as shown in FIGS. 17A and 17B, but also errors as shown in FIGS. 18A and 18B. , there is also an error due to the estimated amount of soot incineration. However, in the technique described in Patent Document 1, when a difference occurs between the first estimated amount and the second estimated amount, the soot accumulation amount estimator always corrects the deviation. Therefore, the estimation unit that calculates the accurate estimated value will be corrected by the error caused by the estimation of the amount of soot incineration, and an error will occur in the estimated amount of soot deposited during the next GPF regeneration operation. It was necessary to perform correction using the differential pressure sensor again.

It is an object of the present invention to provide an internal combustion engine control device that takes the above-mentioned problems into account and can correct errors that occur when estimating the remaining amount of particulate matter using an appropriate estimator.

In order to solve the above problems and achieve the objectives, an internal combustion engine control device includes a control unit that controls a regeneration operation of a filter that is provided in an exhaust passage and collects particulate matter in exhaust gas. The control section includes an accumulation amount estimating section, an incineration amount estimating section, a remaining amount estimating section, and an estimation error determining section. The accumulation amount estimation unit estimates the accumulation amount of particulate matter deposited on the filter. The incineration amount estimation unit estimates the incineration amount of particulate matter that is incinerated during the regeneration operation. The remaining amount estimating section estimates the remaining amount of particulate matter remaining in the filter based on the estimated accumulated amount estimated by the accumulated amount estimating section and the estimated incinerated amount estimated by the incinerated amount estimating section. The estimation error determination section then determines whether the error in the estimated remaining amount estimated by the remaining amount estimation section is an error caused by the accumulation amount estimation section or an error caused by the incineration amount estimation section, and Correction is made for this.

According to the internal combustion engine control device configured as described above, an error that occurs when estimating the remaining amount of particulate matter can be corrected by an appropriate estimator.

1 is a schematic configuration diagram showing the configuration of an internal combustion engine equipped with an internal combustion engine control device according to an embodiment. 1 is a block diagram showing a control system of an internal combustion engine control device according to an embodiment. FIG. FIG. 2 is a block diagram showing a GPF control device of an internal combustion engine control device according to an embodiment. It is a flowchart which shows the 1st operation example of the calculation operation of the estimated residual amount of soot in the internal combustion engine control device concerning the example of embodiment. It is a time chart which shows the 1st operation example of the calculation operation of the estimated residual amount of soot in the internal combustion engine control device concerning the example of embodiment, and is a figure which shows just before regeneration of GPF. It is a time chart which shows the 1st operation example of the calculation operation of the estimated residual amount of soot in the internal combustion engine control device concerning the example of embodiment, and is a figure which shows immediately after regeneration of GPF. It is an explanatory view showing an actual value and an estimated value of soot accumulation amount concerning a conventional example. FIG. 3 is an explanatory diagram showing actual values and estimated values of the amount of soot deposited in the internal combustion engine control device according to the embodiment. 12 is a flowchart illustrating a second operation example of an operation for calculating an estimated residual amount of soot in the internal combustion engine control device according to the embodiment. 12 is a flowchart illustrating a second operation example of an operation for calculating an estimated residual amount of soot in the internal combustion engine control device according to the embodiment. It is a time chart which shows the 2nd operation example of the calculation operation of the estimated residual amount of soot in the internal combustion engine control device concerning the example of embodiment, and is a figure which shows just before regeneration of GPF. It is a time chart which shows the 2nd operation example of the calculation operation of the estimated residual amount of soot in the internal combustion engine control device concerning the example of embodiment, and is a figure which shows the state in which the internal combustion engine stopped. 3 is a time chart illustrating an operation example of conventional GPF playback control. FIG. 2 is a schematic diagram showing a first method in a conventional method for estimating the amount of soot remaining. This shows a second method in the conventional method for estimating the amount of soot remaining, and FIGS. 15A to 15C are schematic diagrams showing the second method. FIG. 3 is a schematic diagram showing a third method in the conventional method for estimating the amount of soot remaining. 17A shows a case where there is no error, and FIG. 17B is an explanatory diagram showing an error caused by the soot accumulation amount estimation logic. 18A shows a case where there is no error, and FIG. 18B is an explanatory diagram showing an error caused by the soot incineration amount estimation logic.

Embodiments of the internal combustion engine control device will be described below with reference to FIGS. 1 to 12.
Note that common members in each figure are given the same reference numerals.

1. Embodiment 1-1. Configuration Example of Internal Combustion Engine Control First, a configuration example of an internal combustion engine control device according to an embodiment (hereinafter referred to as "this example") will be described with reference to FIGS. 1 to 3.
FIG. 1 is a schematic configuration diagram showing an example of the configuration of an internal combustion engine equipped with an internal combustion engine control device.

The internal combustion engine 2 shown in FIG. 1 is a direct injection type engine. The internal combustion engine 2 is a four-stroke engine that repeats four strokes: an intake stroke, a compression stroke, a combustion (expansion) stroke, and an exhaust stroke. Further, the internal combustion engine 2 is, for example, a multi-cylinder engine including four cylinders.
Note that the number of cylinders that the internal combustion engine 2 has is not limited to four, and may have six or eight or more cylinders.

The internal combustion engine 2 includes an air flow sensor 41 that measures the amount of intake air, a compressor 42 that supercharges the intake air, an intercooler 43 that cools the supercharged intake air, and a throttle valve 44 that adjusts the gas sucked into the cylinder 45. Equipped with. A throttle sensor 59 is provided near the throttle valve 44 to detect the opening degree of the throttle valve 44.

The internal combustion engine 2 also includes a spark plug 46 that supplies ignition energy to the cylinder 45 of each cylinder, a fuel injection device 49 that injects fuel into the cylinder 45 of each cylinder, and a fuel injection device 49 that injects fuel and gas that has flowed into the cylinder 45. The piston 50 compresses the air-fuel mixture. Further, the internal combustion engine 2 includes an intake valve 47 that adjusts the air-fuel mixture flowing into the cylinder 45, and an exhaust valve 48 that discharges exhaust gas after combustion.

The internal combustion engine 2 also includes a crank angle sensor 51 that detects a signal from a signal rotor attached to the crankshaft 60, and a water temperature sensor 52 that measures the temperature of cooling water. Further, the internal combustion engine 2 includes a turbine 53 that transmits the kinetic energy of exhaust gas to the compressor 42 via a shaft, and a three-way catalyst 54 that purifies harmful substances in the exhaust gas. An A/F sensor 55 is installed near the three-way catalyst 54 to detect the oxygen concentration contained in the exhaust gas.

The internal combustion engine 2 also includes a gasoline particulate filter (hereinafter referred to as "GPF") 56 provided downstream of the three-way catalyst 54. The GPF 56 collects particulate matter, so-called soot, contained in exhaust gas. The GPF 56 is formed of a porous material having fine pores on its wall surface. Then, the GPF 56 collects and deposits soot in minute holes formed in the wall surface.

Further, a GPF temperature sensor 57 is provided upstream of the GPF 56, that is, between the three-way catalyst 54 and the GPF 56. GPF temperature sensor 57 measures the temperature of GPF 56. If the temperature is above the regeneration temperature, the GPF 56 is regenerated by supplying oxygen and incinerating soot through a fuel cut (hereinafter referred to as F/C).

Further, the GPF 56 is provided with a differential pressure sensor 58. The differential pressure sensor 58 measures the difference in pressure between the upstream side and the downstream side of the GPF 56 (differential pressure). The differential pressure sensor 58 and the GPF temperature sensor 57 are connected to the internal combustion engine control device 11 (see FIG. 2), and output the measured differential pressure information and temperature information to the internal combustion engine control device 11.

[ECU configuration]
Next, the configuration of the internal combustion engine control device 11 that controls the internal combustion engine 2 will be explained with reference to FIG.
FIG. 2 is a block diagram showing the configuration of the internal combustion engine control device 11. As shown in FIG.

As shown in FIG. 2, the internal combustion engine control device 11 includes an input circuit 301, an input/output port 302, a RAM (Random Access Memory) 303, a ROM (Read Only Memory) 304, and a CPU (Central Processing Unit) 305. has. Further, the internal combustion engine control device 11 includes an electronically controlled throttle valve drive circuit 306, a fuel injection device drive circuit 307, and an ignition output circuit 308.

The input circuit 301 receives outputs from various sensors such as a throttle sensor 59, an air flow sensor 41, a crank angle sensor 51, a water temperature sensor 52, an A/F sensor 55, a GPF temperature sensor 57, a differential pressure sensor 58, and the like. The input circuit 301 performs signal processing such as noise removal on the input signal and sends it to the input/output port 302 . The value input to the input port of the input/output port 302 is stored in the RAM 303.

The ROM 304 stores control programs that describe the contents of various calculation processes executed by the CPU 305, as well as MAPs, data tables, etc. used in each process. The RAM 303 is provided with a storage area for storing values input to the input/output port 302 and values representing the operation amount of each actuator calculated according to the control program.
Furthermore, the values representing the operation amounts of each actuator stored in the RAM 303 are sent to the output port of the input/output port 302 .

A drive signal that achieves the target opening degree of the throttle valve 44 set at the output port of the input/output port 302 is sent to the motor that drives the throttle valve 44 via an electronically controlled throttle valve drive circuit 306. The drive signal for the fuel injection device 49 is an ON/OFF signal that is ON when the valve is opened and OFF when the valve is closed. The drive signal for the fuel injector 49 set to the output port of the input/output port 302 is amplified by the fuel injector drive circuit 307 to enough energy to drive the fuel injector 49 and is supplied to the fuel injector 49. be done.

The activation signal for the spark plug 46 is an ON/OFF signal that is turned ON when the primary coil in the ignition output circuit 308 is conducting, and turned OFF when the primary coil is not conducting. The ignition timing of the spark plug 46 is the point in time when the activation signal for the spark plug 46 changes from ON to OFF. An activation signal for the spark plug 46 set at the output port of the input/output port 302 is amplified by the ignition output circuit 308 to sufficient energy necessary for ignition, and is supplied to the spark plug 46 .

Further, the CPU 305 is provided with a GPF control device 400 (see FIG. 3), which is an example of a filter control section that controls regeneration of the GPF 56.

[Configuration of GPF control device]
Next, the configuration of the GPF control device 400 will be described with reference to FIG. 3.
FIG. 3 is a block diagram showing the configuration of the GPF control device 400.

As shown in FIG. 3, the GPF control device 400 includes an input section 401, a soot accumulation amount estimating section 402, a soot incineration amount estimating section 403, a soot remaining amount estimating section 404, and a differential pressure type soot remaining amount estimating section 405. , an estimation error calculation section 406 , and a reproduction control section 407 . Furthermore, the GPF control device 400 includes an estimation error determination section 408.

The input unit 401 acquires differential pressure information measured by the differential pressure sensor 58 and temperature information measured by the GPF temperature sensor 57 from the RAM 303 . Furthermore, a detection flag for GPF regeneration processing is input to the input unit 401 from the CPU 305 . The CPU 305 detects or predicts the implementation of the playback operation of the GPF 56 in advance based on map data and navigation information, and inputs a detection flag to the input unit 401.

The soot accumulation amount estimating section 402, which indicates the accumulation amount estimating section, is composed of a MAP and a physical formula. The soot accumulation amount estimation section 402 receives input from the input section 401 of the GPF temperature indicating the temperature of the GPF 56, the water temperature, the F/C flag, the fuel injection amount, and the like. Then, the soot accumulation amount estimation unit 402 calculates the estimated soot accumulation amount, which is the amount of soot accumulated in the GPF 56, from the input GPF temperature, water temperature, F/C flag, fuel injection amount, etc. The soot accumulation amount estimation section 402 outputs the calculated estimated soot accumulation amount to the soot remaining amount estimation section 404 .

The soot incineration amount estimating section 403, which indicates the incineration amount estimating section, is composed of a MAP and a physical formula. Similar to the soot accumulation amount estimating section 402, the soot incineration amount estimating section 403 receives input from the input section 401 of the GPF temperature indicating the temperature of the GPF 56, the water temperature, the F/C flag, the fuel injection amount, and the like. Then, the soot incineration amount estimating unit 403 calculates an estimated soot incineration amount, which is the amount of soot incinerated during the regeneration process, from the input GPF temperature, water temperature, F/C flag, fuel injection amount, etc. The soot incineration amount estimating section 403 outputs the calculated estimated soot incineration amount to the soot remaining amount estimating section 404 .

A residual soot amount estimating section 404 uses the estimated soot accumulation amount calculated by the soot accumulation amount estimating section 402 and the estimated soot incineration amount calculated by the soot incineration amount estimating section 403 to calculate the estimated soot remaining amount. seek. Then, the soot remaining amount estimating section 404 outputs the calculated estimated soot remaining amount to the estimation error calculating section 406.
Note that the estimated soot remaining amount X is determined by the following formula 1.
[Formula 1]
Estimated soot remaining amount X = Estimated soot accumulation amount - Estimated soot incineration amount

A differential pressure residual amount estimating section 405 indicating a differential pressure residual amount estimating section acquires differential pressure information from the input section 401 . Then, the differential pressure type remaining soot amount estimating unit 405 calculates the estimated differential pressure remaining amount Y, which is the amount of soot deposited on the GPF 56, based on the differential pressure information. The differential pressure type remaining soot amount estimating section 405 outputs the produced differential pressure estimated remaining soot amount Y to the estimation error calculation section 406.

The estimated error calculation unit 406 takes the differential pressure estimated soot remaining amount Y calculated by the differential pressure type soot remaining amount estimating unit 405 as the true value, and calculates the difference D of the estimated soot remaining amount X calculated by the soot remaining amount estimating unit 404, that is, the estimate. Calculate the error. Then, the estimated error calculation unit 406 outputs the calculated estimated error to the estimated error determination unit 408.

The estimated error determining unit 408 determines whether the estimated error obtained from the estimated error calculating unit 406 is an error resulting from the amount of soot accumulation or an error resulting from the amount of soot incineration. Based on the determination result, the estimation error determination unit 408 outputs the estimation error to the soot accumulation amount estimation unit 402 or the soot incineration amount estimation unit 403, and corrects the soot accumulation amount estimation unit 402 or the soot incineration amount estimation unit 403. Then, the corrected soot accumulation amount estimation unit 402 and soot incineration amount estimation unit 403 correct the fixed soot accumulation amount and the estimated soot incineration amount, and output the corrected values to the soot remaining amount estimation unit 404.

Further, the soot remaining amount estimation unit 404 corrects the estimated soot remaining amount based on the corrected value and outputs it to the reproduction control unit 407. The regeneration control unit 407 generates a regeneration command value for regeneration control based on the estimated remaining soot amount (correction) calculated and corrected by the remaining soot amount estimating unit 404 and the GPF temperature etc. input to the input unit 401. Calculate. The regeneration command value is information regarding fuel cut permission and ignition retard.

The regeneration command value calculated by the regeneration control unit 407 is changed into a signal for the spark plug 46 and a drive signal for the fuel injection device 49 by the ignition timing control unit and the fuel injection control unit in the CPU 305, and the input/output port 302 (see FIG. 3). The set drive signal is output from the input/output port 302 to the fuel injection device drive circuit 307 and the ignition output circuit 308.

1-2. First Operation Example Next, a first operation example of the internal combustion engine control device 11 having the above-described configuration will be described with reference to FIGS. 4 to 6. In the first operation example, an operation for calculating the estimated remaining amount of soot will be described.
FIG. 4 is a flowchart illustrating an example of an operation for calculating the estimated remaining amount of soot. 5 and 6 are time charts showing the calculation operation of the estimated remaining amount of soot. FIG. 5 is a diagram showing immediately before the GPF 56 is regenerated, and FIG. 6 is a diagram showing immediately after the GPF 56 is regenerated.

As shown in FIG. 4, first, the CPU 305 detects implementation of F/C based on map data and navigation information while the vehicle is running (step S11). Then, as shown in FIG. 5, the CPU 305 measures the time t1 of the executed F/C. Next, the CPU 305 determines whether the time t1 of the executed F/C is longer than a certain time (step S12). That is, the CPU 305 determines whether the regeneration operation of the GPF 56 has been performed for a certain period of time or more.

In the process of step S12, if it is determined that the F/C time t1 is less than the certain time (NO determination in step S12), the CPU 305 ends the process. On the other hand, if it is determined in the process of step S12 that the F/C time t1 is equal to or longer than the predetermined time (YES determination in step S12), the GPF control device 400 causes the GPF 56 to accumulate It is determined that all of the soot has been incinerated.

Then, the soot accumulation amount estimating unit 402 considers that the soot accumulation amount of the GPF 56 is zero (step S13). That is, the soot accumulation amount estimation unit 402 calculates that the estimated soot accumulation amount is zero. As a result, the initial value of the soot accumulation amount is cleared to zero, that is, a reset process is performed. In addition, in the process of step S13, the estimated remaining amount of soot is also reset to zero in the remaining soot amount estimating unit 404.

Further, when the initial value reset process is completed, the soot accumulation amount estimation unit 402 calculates the estimated soot accumulation amount from information such as the GPF temperature, water temperature, and fuel injection amount. Then, the soot accumulation amount estimation unit 402 outputs the calculated estimated soot accumulation amount to the soot remaining amount estimation unit 404. Next, the remaining soot amount estimating unit 404 determines whether the remaining amount of soot in the GPF 56 is determined by the amount of soot accumulated in the GPF 56 during a period t2 (see FIG. 5) until the next regeneration operation occurs, that is, during a period t2 until the next F/C is performed. (remaining amount of soot=amount of soot deposited) (step S14). The soot remaining amount estimation unit 404 estimates the estimated soot accumulation amount calculated by the soot accumulation amount estimating unit 402 to be the soot remaining amount.

Next, the CPU 305 predicts whether or not F/C will occur based on the map data and navigation information, that is, the execution of the regeneration operation of the GPF 56 (step S15). In the process of step S15, if it is determined that F/C will not occur (NO determination in step S15), the CPU 305 ends the process.

On the other hand, if the CPU 305 determines that F/C occurs (YES determination in step S15), the CPU 305 inputs a detection flag to the input unit 401. When the detection flag is input, the input unit 401 acquires the differential pressure information ΔP (see FIG. 5) of the GPF 56 at t3 immediately before the start of F/C from the differential pressure sensor 58, and sends the difference to the differential pressure type soot remaining amount estimation unit 405. Pressure information ΔP is input (step S16). Then, the differential pressure type remaining soot amount estimating unit 405 calculates the estimated remaining soot amount based on the differential pressure (differential pressure estimated remaining amount of soot) Y based on the differential pressure information ΔP acquired from the input unit 401.

Next, the estimated error calculation unit 406 determines whether there is an error between the estimated remaining soot amount Y based on the differential pressure and the estimated remaining soot amount X based on the logical operation (step S17). In the process of step S17, the estimation error calculation unit 406 obtains the estimated soot remaining amount Y calculated by the differential pressure type soot remaining amount estimating unit 405 as the estimated soot remaining amount Y based on the differential pressure. Furthermore, the estimation error calculation unit 406 obtains the estimated remaining soot amount X calculated by the soot accumulation amount estimating unit 402 and estimated by the soot remaining amount estimating unit 404 as the estimated remaining soot amount X by a logical operation. Estimation error calculating section 406 calculates the difference between estimated soot remaining amount Y and estimated soot remaining amount X, and calculates an estimation error. Then, the estimation error calculation unit 406 determines whether there is an error, for example, based on whether the calculated estimation error exceeds a threshold value.

In the process of step S17, if the estimated error calculation unit 406 determines that there is no error (NO determination in step S17), the process proceeds to step S19, which will be described later.

Here, during the period t2 from the previous regeneration operation of the GPF 56 to the current regeneration operation of the GPF 56, soot was not incinerated even once. This can be regarded as an error caused by Therefore, in the process of step S17, if the estimation error calculation unit 406 determines that there is an error (YES determination in step S17), the estimation error determination unit 408 determines that the estimation error calculated by the estimation error calculation unit 406 is the amount of soot deposited. It is determined that the error is caused by Then, as shown in FIG. 5, the estimation error determination unit 408 corrects the soot accumulation amount estimation unit 402 (step S18).

By correcting the soot accumulation amount estimating section 402, the soot accumulation amount estimating section 402 corrects the estimated soot accumulation amount. Then, the soot accumulation amount estimation unit 402 outputs the corrected estimated soot accumulation amount to the soot remaining amount estimation unit 404. The soot remaining amount estimation unit 404 estimates the corrected estimated soot accumulation amount to be the soot remaining amount. Further, the soot remaining amount estimation section 404 outputs the estimated soot remaining amount (correction) to the reproduction control section 407.

Next, the CPU 305 determines whether the reproduction operation of the GPF 56 has been completed (step S19). For example, the CPU 305 determines that the regeneration operation of the GPF 56 has ended when the F/C execution flag is turned off. Alternatively, when estimating whether to perform F/C in the process of step S15, the CPU 305 estimates the time required for F/C. Then, the CPU 305 determines that the regeneration operation of the GPF 56 has ended when the F/C time reaches the F/C time estimated in advance.

In the process of step S19, if it is determined that the regeneration operation of the GPF 56 has ended (YES determination in step S19), the CPU 305 inputs the detection flag to the input unit 401.
When the detection flag is input, the input unit 401 acquires the differential pressure information ΔP of the GPF 56 immediately after the end of regeneration t4 (see FIG. 6), that is, immediately after the end of F/C from the differential pressure sensor 58 (see FIG. 6), The differential pressure information ΔP is input to the differential pressure type residual soot amount estimation unit 405 (step S20). Then, the differential pressure type remaining soot amount estimating unit 405 calculates the estimated remaining soot amount based on the differential pressure (differential pressure estimated remaining amount of soot) Y based on the differential pressure information ΔP acquired from the input unit 401.

Further, during the regeneration operation of the GPF 56, that is, during execution of F/C, the soot incineration amount estimation unit 403 calculates the estimated soot incineration amount from information such as the GPF temperature, water temperature, and fuel injection amount. Then, the soot incineration amount estimating section 403 outputs the calculated estimated soot incineration amount to the soot remaining amount estimating section 404. The soot remaining amount estimating unit 404 calculates the estimated soot remaining amount by calculating the difference between the estimated soot incineration amount calculated by the soot incineration amount estimating unit 403 from the corrected soot accumulation amount.

Next, the estimated error calculation unit 406 determines whether there is an error between the estimated remaining soot amount Y based on the differential pressure and the estimated remaining soot amount X based on the logical operation (step S21). In the process of step S21, the estimation error calculation unit 406 obtains the estimated soot remaining amount Y calculated by the differential pressure type soot remaining amount estimating unit 405 as the estimated soot remaining amount Y based on the differential pressure. Furthermore, the estimation error calculation unit 406 obtains the estimated remaining soot amount X calculated by the soot accumulation amount estimating unit 402 and estimated by the soot remaining amount estimating unit 404 as the estimated remaining soot amount X by a logical operation. Estimation error calculating section 406 calculates the difference between estimated soot remaining amount Y and estimated soot remaining amount X, and calculates an estimation error.

In the process of step S21, if the estimated error calculation unit 406 determines that there is no error (NO determination in step S21), the CPU 305 ends the process.

Here, since the soot accumulation amount has already been corrected, the estimation error calculated at t4 immediately after the end of regeneration can be regarded as an error caused by the soot incineration amount estimation unit 403. Therefore, in the process of step S21, if the estimated error calculating unit 406 determines that there is an error (YES determination in step S21), the estimated error determining unit 408 determines that the estimated error calculated by the estimated error calculating unit 406 is the amount of soot incinerated. It is determined that the error is caused by Then, the estimation error determination unit 408 corrects the soot incineration amount estimation unit 403 (step S22).

By correcting the soot incineration amount estimating section 403, the soot incineration amount estimating section 403 corrects the estimated soot incineration amount. Then, the soot incineration amount estimating unit 403 outputs the corrected estimated soot incineration amount to the soot remaining amount estimating unit 404. The soot remaining amount estimating unit 404 estimates the value obtained by subtracting the corrected estimated soot incineration amount from the corrected estimated soot accumulation amount to be the soot remaining amount. Then, the soot remaining amount estimation unit 404 outputs the estimated soot remaining amount (correction) to the reproduction control unit 407. This completes the operation of calculating the estimated remaining amount of soot in the internal combustion engine control device 11.

Further, in the processing of step S17 and step S21 described above, if the estimation error calculation unit 406 determines that the estimation error is equal to or greater than a certain value, the estimation error calculation unit 406 determines that the differential pressure sensor 58 is malfunctioning. Thereby, a failure determination of the differential pressure sensor 58 can be performed.
Note that the value used for failure determination is a value larger than the threshold value used for determining the presence or absence of an error.

As described above, according to the internal combustion engine control device 11 of this example, by determining whether the estimation error is caused by the soot accumulation amount estimating section 402 or the soot incineration amount estimating section 403, the respective Errors can be corrected for appropriate estimators.

Moreover, after the process of step S22, the estimated soot remaining amount (corrected) Z1 calculated by the soot remaining amount estimation unit 404 may be used as an initial value when calculating the soot remaining amount next time. That is, the next estimated remaining soot amount Z2 can be calculated by the estimated remaining soot amount (corrected) Z1 + the next estimated soot accumulation amount (after correction) W2 - the next estimated soot incineration amount (after correction) W3. The soot accumulation amount estimation unit 402 stores the differential pressure information Q when calculating the estimated remaining soot amount (corrected) Z1, and calculates the differential pressure from the actual differential pressure when correcting the next estimated soot accumulation amount W2. Pull information Q. Thereby, it is possible to obtain the differential pressure only for the next estimated soot accumulation amount W2, and it is possible to appropriately correct the next estimated soot accumulation amount W2.

1-3. Comparison with Conventional Example Next, a comparison example of the actual value and estimated value of the amount of soot deposited in the internal combustion engine control device 11 of the conventional example and the present example will be described with reference to FIGS. 7 and 8.
7 and 8 show actual values and estimated values of the amount of soot deposited. FIG. 7 shows a conventional example, and FIG. 8 shows an example calculated by the internal combustion engine control device 11 of the present example described above. shows.

In the conventional example shown in FIG. 7, as in the third method shown in FIG. This has been corrected. That is, even if the error is due to the soot incineration amount estimation section, the soot accumulation amount estimation section is corrected. Therefore, as shown in FIG. 7, during the next regeneration operation, an error due to the previous correction occurs in the soot accumulation amount estimating section. Then, the difference between the actual value and the estimated value of the amount of soot deposit increases. As a result, in the conventional example, in order to eliminate this difference, the number of corrections based on differential pressure information from the differential pressure sensor increases.

On the other hand, in the internal combustion engine control device 11 of this example, as described above, by determining whether the estimation error is caused by the soot accumulation amount estimating section 402 or the soot incineration amount estimating section 403, , each error is corrected by an appropriate estimator. That is, the error caused by the soot incineration amount estimating section 403 is corrected by the soot incineration amount estimating section 403, not by the soot accumulation amount estimating section 402.

Therefore, as shown in FIG. 8, an error due to the correction does not occur in the next regeneration operation, and the difference between the actual value and estimated value of the amount of soot accumulation can be reduced or eliminated. As a result, in the internal combustion engine control device 11 of this example, the number of times of correction based on the differential pressure information of the differential pressure sensor 58 can be reduced compared to the conventional example.

2. Second Operation Example Next, a second operation example of the internal combustion engine control device 11 having the above-described configuration will be described with reference to FIGS. 9 to 12. In the first operation example, an operation for calculating the estimated remaining amount of soot will be described.
9 and 10 are flowcharts illustrating an example of the operation for calculating the estimated remaining amount of soot. 11 and 12 are time charts showing the calculation operation of the estimated residual amount of soot. FIG. 11 is a diagram showing immediately before regeneration of the GPF 56, and FIG. 12 is a diagram showing a state in which the internal combustion engine 2 is stopped.

The difference between this second operation example and the first operation example is that before the regeneration operation of the GPF 56 ends, it is determined whether the internal combustion engine 2 is stopped due to idling stop or the like. As shown in FIGS. 9 and 11, the processing from step S31 to step S38 is the same as the processing from step S11 to step S18 in the first operation example, so a description thereof will be omitted.

As shown in FIG. 10, when the process of step S38 is completed, the CPU 305 determines whether the internal combustion engine 2 has stopped during the regeneration operation of the GPF 56 (step S41). In the process of step S41, if the CPU 305 determines that the internal combustion engine 2 is not stopped (NO determination in step S41), the process moves to step S42. Note that the processing from step S42 to step S45 is similar to the processing from step S19 to step S22 in the first operation example. Therefore, the error occurring during this time is determined to be an error caused by the soot incineration amount estimating section 403, and the soot incineration amount estimating section 403 is corrected.

On the other hand, as shown in FIG. 10, when the CPU 305 determines that the internal combustion engine 2 has stopped in the process of step S41 (YES determination in step S41), the differential pressure type soot remaining amount estimation unit 405 The differential pressure information ΔP (see FIG. 12) of the GPF 56 is recorded (step S46). Further, the soot remaining amount estimating unit 404 records the estimated soot remaining amount based on the logical operation immediately after the stop (step S47). That is, the soot remaining amount estimating unit 404 records the value obtained by subtracting the estimated soot incineration amount calculated by the soot incineration amount estimating unit 403 immediately after the stop from the corrected estimated soot accumulation amount as the estimated soot remaining amount.

Next, as shown in FIG. 12, when the internal combustion engine 2 is restarted (step S48), the estimated error calculation unit 406 determines that there is an error between the estimated remaining soot amount Y based on the differential pressure and the estimated remaining soot amount X based on the logical operation. It is determined whether there is one (step S49).

In the process of step S49, the differential pressure type soot remaining amount estimating unit 405 calculates the estimated soot remaining amount Y based on the differential pressure using the differential pressure information recorded at t5 immediately after the stoppage of the internal combustion engine 2, and estimates It is output to the error calculation section 406. Further, the soot remaining amount estimating section 404 outputs the estimated soot remaining amount recorded at t5 immediately after the internal combustion engine 2 stops to the estimation error calculating section 406 as the estimated soot remaining amount X based on the logical operation. Then, the estimation error calculation unit 406 calculates the difference between the estimated remaining amount of soot Y and the estimated remaining amount of soot X, and calculates the estimation error.

In the process of step S49, if the estimated error calculation unit 406 determines that there is no error (NO determination in step S49), the CPU 305 ends the process.

Here, since the soot accumulation amount has already been corrected, the estimation error calculated at t5 immediately after the internal combustion engine 2 stops can be regarded as an error caused entirely by the soot incineration amount estimation unit 403. Therefore, in the process of step S49, if the estimated error calculating unit 406 determines that there is an error (YES determination in step S49), the estimated error determining unit 408 determines that the estimated error calculated by the estimated error calculating unit 406 is the amount of soot incinerated. It is determined that the error is caused by Then, the estimation error determination unit 408 corrects the soot incineration amount estimation unit 403 (step S50).

By correcting the soot incineration amount estimating section 403, the soot incineration amount estimating section 403 corrects the estimated soot incineration amount. Then, the soot incineration amount estimating unit 403 outputs the corrected estimated soot incineration amount to the soot remaining amount estimating unit 404. The soot remaining amount estimating unit 404 estimates the value obtained by subtracting the corrected estimated soot incineration amount from the corrected estimated soot accumulation amount to be the soot remaining amount. Then, the soot remaining amount estimation unit 404 outputs the estimated soot remaining amount (correction) to the reproduction control unit 407. This completes the operation of calculating the estimated remaining amount of soot in the internal combustion engine control device 11.

In this second operation example, as in the first operation example, the error between the estimated soot remaining amount based on the differential pressure and the estimated soot remaining amount based on the logical operation can be corrected by an appropriate estimator. Therefore, as shown in FIG. 8, the error caused by the correction does not occur in the next regeneration operation, and the difference between the actual value and the estimated value of the soot accumulation amount can be reduced or eliminated, and the differential pressure sensor 58 The number of corrections based on differential pressure information can be reduced.

Note that the present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the gist of the invention as set forth in the claims.

Furthermore, although an example has been described in which a direct injection type internal combustion engine that injects fuel directly into the combustion chamber of the cylinder 45 is applied as the internal combustion engine, the present invention is not limited to this. For example, the present invention can be applied to an internal combustion engine in which the fuel injection device 49 is disposed near an intake port in an intake pipe or near a throttle valve to inject fuel into the intake pipe.

DESCRIPTION OF SYMBOLS 1...Vehicle, 2...Internal combustion engine, 11...Internal combustion engine control device, 45...Cylinder, 46...Spark plug, 47...Intake valve, 48...Exhaust valve, 49...Fuel injection device, 50...Piston, 54...Three-way catalyst , 56...GPF (gasoline particulate filter), 57...GPF temperature sensor, 58...differential pressure sensor, 301...input circuit, 302...input/output port, 303...RAM, 304...ROM, 305...CPU, 306...electronic control Throttle valve drive circuit, 307...Fuel injection device drive circuit, 308...Ignition output circuit 400...GPF control device (control unit), 401...Input unit, 402...Soot accumulation amount estimation unit (accumulation amount estimation unit), 403...Soot Incineration amount estimating unit (incineration amount estimating unit), 404... soot remaining amount estimating unit (remaining amount estimating unit), 405... differential pressure type soot remaining amount estimating unit (differential pressure type remaining amount estimating unit), 406... estimation error calculation unit, 407... Reproduction control unit, 408... Estimation error determination unit

Claims (10)

A control unit that controls the regeneration operation of a filter that is installed in the exhaust passage and collects particulate matter in the exhaust,
The control unit includes:
a deposition amount estimation unit that estimates the deposition amount of the particulate matter deposited on the filter;
an incineration amount estimation unit that estimates the incineration amount of the particulate matter that is incinerated during the regeneration operation;
a remaining amount estimating section that estimates the remaining amount of the particulate matter remaining in the filter based on the estimated accumulation amount estimated by the accumulated amount estimating section and the estimated incineration amount estimated by the incineration amount estimating section;
Determining whether the error in the estimated remaining amount estimated by the remaining amount estimating section is an error caused by the accumulated amount estimating section or the incineration amount estimating section, and correcting the determined estimating section. An estimation error determination unit;
Internal combustion engine control device. The control unit includes:
a differential pressure residual amount estimation unit that estimates the particulate matter remaining in the filter based on a differential pressure that is a difference between pressures on the upstream side and downstream side of the filter;
2. An estimated error calculating section that calculates the error of the estimated remaining amount estimated by the remaining amount estimating section from the estimated remaining amount based on the differential pressure estimated by the differential pressure type remaining amount estimating section. internal combustion engine control device. The estimation error determining section is configured to determine whether the error in the estimated remaining amount estimated by the remaining amount estimating section is determined from the time when the filter regeneration operation is performed for a certain period of time or more until the filter regeneration operation is performed next time. The internal combustion engine control device according to claim 2, wherein the error is determined to be caused by the accumulation amount estimating section. When it is determined that the regeneration operation of the filter has been carried out for a predetermined period of time or more, the accumulation amount estimating unit resets an initial value when the estimated accumulation amount is zero;
The internal combustion engine control device according to claim 3, wherein the remaining amount estimating unit determines the estimated remaining amount to be the estimated accumulated amount until a regeneration operation of the filter is performed next. The estimation error determining unit determines that the error in the estimated remaining amount estimated by the remaining amount estimating unit immediately after the filter regenerating operation is performed for a predetermined period of time or more, and immediately after the next filter regenerating operation is performed. The internal combustion engine control device according to claim 4, wherein the error is determined to be caused by the incineration amount estimation section. The internal combustion engine control device according to claim 1, wherein the accumulation amount estimating section and the incineration amount estimating section calculate the estimated accumulation amount and the estimated incineration amount from a MAP or a physical formula. When the internal combustion engine stops after correcting the accumulation amount estimating section, the differential pressure type remaining amount estimating section records the differential pressure of the filter immediately after the stop, and the remaining amount estimating section performs the calculation immediately after stopping. The internal combustion engine control device according to claim 2, wherein the estimated remaining amount is recorded. When the internal combustion engine is restarted, the differential pressure type remaining amount estimating unit estimates the estimated remaining amount immediately after stopping based on the differential pressure recorded immediately after stopping,
The internal combustion engine control device according to claim 7, wherein the estimated error calculating section calculates an error in the estimated remaining amount recorded by the remaining amount estimating section immediately after stopping from the estimated remaining amount immediately after stopping. The estimated error calculation unit determines that a differential pressure sensor that measures the differential pressure of the filter is malfunctioning when determining that the error in the estimated remaining amount estimated by the remaining amount estimating unit is equal to or greater than a certain value. The internal combustion engine control device according to claim 2. The internal combustion engine according to claim 1, wherein the remaining amount estimating section sets the estimated remaining amount after correcting the accumulated amount estimating section and the incineration amount estimating section as an initial value when estimating the estimated remaining amount next time. Engine control device.

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