Controller for internal combustion engine, control method for internal combustion engine, and program

Abstract

A control device for an internal combustion engine, a method for controlling an internal combustion engine, and a program are provided. A pressure sensor detects the differential pressure between the upstream and downstream parts of an exhaust passage for a filter as a pressure value. A processing circuit calculates a reference ratio when it is determined that the pressure sensor is detecting the pressure value normally. The reference ratio is the ratio between the pressure value detected by the pressure sensor and the reference pressure. For a vehicle trip in which the reference ratio is stored, the reference pressure is calculated based on driving parameters during the next trip. The pressure value is calculated by multiplying the calculated reference pressure by the stored reference ratio.

Description

Technology Field

[0001] [Cross-reference of related applications]

[0002] The present application claims priority to Japanese Patent Application No. 2025-038128 filed on March 11, 2025, the entirety of which is incorporated herein by reference.

[0003] The present disclosure relates to a control device for an internal combustion engine, a method for controlling an internal combustion engine, and a program. Background Technology

[0004] In the exhaust passage of an internal combustion engine described in Japanese Patent Publication No. 2012-184756, a filter is provided to collect particulate matter in the exhaust. The exhaust passage has an upstream exhaust section upstream of the filter and a downstream exhaust section downstream of the filter. A pressure pipe is connected to the upstream exhaust section upstream of the filter and the downstream exhaust section downstream of the filter within the exhaust passage. The pressure pipe is provided with a pressure sensor that detects the differential pressure between the pressure of the upstream exhaust section and the pressure of the downstream exhaust section as a pressure value. The control device of the above document performs control regarding the filter based on the pressure value detected by the pressure sensor. The problem to be solved

[0005] According to one aspect of the present disclosure, a control device for an internal combustion engine is provided. The control device has a processing circuit. The processing circuit is configured to execute a determination process for determining whether a pressure sensor is detecting a pressure value normally. The internal combustion engine is mounted in a vehicle. A filter is provided in the exhaust passage of the internal combustion engine to collect particulate matter in the exhaust of the exhaust passage. A pressure pipe is connected to an upstream portion of the exhaust passage relative to the filter and a downstream portion of the exhaust passage relative to the filter. The pressure sensor is provided in the pressure pipe and detects the differential pressure between the pressure in the upstream portion and the pressure in the downstream portion as the pressure value. The processing circuit is configured to execute a reference ratio storage process in which, when it is determined in the determination process that the pressure sensor is detecting the pressure value normally, it calculates a reference ratio and stores the reference ratio as a value to be used for the next trip of the vehicle. The next trip is the next trip for the vehicle trip in which the reference ratio is stored. The above reference ratio is the ratio of the pressure value detected by the pressure sensor to the reference pressure, which is the reference value of the pressure value. The above reference pressure is calculated based on the operating parameters involved in the pressure value. The processing circuit is configured to execute a pressure value calculation process in the next trip, comprising calculating the reference pressure based on the operating parameters and calculating the pressure value by multiplying the calculated reference pressure by the stored reference ratio.

[0006] According to another aspect of the present disclosure, a method for controlling an internal combustion engine is provided. The control method comprises determining whether a pressure sensor is normally detecting a pressure value by means of a processing circuit of a control device. The internal combustion engine is mounted in a vehicle. A filter is provided in the exhaust passage of the internal combustion engine to collect particulate matter in the exhaust of the exhaust passage. A pressure pipe is connected to an upstream portion of the exhaust passage relative to the filter and a downstream portion of the exhaust passage relative to the filter. The pressure sensor is provided in the pressure pipe. The pressure sensor detects the differential pressure between the pressure of the upstream portion and the pressure of the downstream portion as the pressure value. The control method comprises calculating a reference ratio by means of the processing circuit when it is determined that the pressure sensor is normally detecting the pressure value. The reference ratio is the ratio of the pressure value detected by the pressure sensor to a reference pressure, which is a reference value of the pressure value. The reference pressure is calculated based on an operating parameter involved in the pressure value. The above control method stores the reference ratio as a value used for the next trip of the vehicle, wherein the next trip is a trip of the vehicle in which the reference ratio is stored, and the reference ratio is stored, and in the next trip, the reference pressure is calculated by the processing circuit based on the driving parameter, and the pressure value is calculated by multiplying the calculated reference pressure by the stored reference ratio by the processing circuit.

[0007] According to another aspect of the present disclosure, a program is provided that is realized by a non-transient computer-readable storage medium storing program code for executing control processing of an internal combustion engine similar to the method above in a processing device.

[0008] With this configuration, a high-precision calculated value of the pressure value can be obtained.

[0009] However, if a pressure sensor malfunctions or the pressure piping becomes clogged, the pressure sensor may be unable to detect the pressure value normally. Therefore, it is desirable to use a calculated value for the pressure value whenever possible. To perform proper control, it is also required to obtain a high-precision calculated pressure value. The above configuration contributes to this. Brief explanation of the drawing

[0010] FIG. 1 is a schematic diagram of an internal combustion engine to which a first embodiment of a control device is applied. FIG. 2 is a flowchart showing the sequence of processing executed by a processing circuit of the same embodiment. Figure 3 is a flowchart showing the sequence of processing executed by the processing circuit of the same embodiment. FIG. 4 is a flowchart showing the sequence of processing executed by the processing circuit of the second embodiment. Specific details for implementing the invention

[0011] FIGS. 1 to 3 illustrate a first embodiment embodying the present disclosure. The first embodiment relates to a control device for an internal combustion engine, a control method, a control processing, a memory medium, a program product, and a program. In the present embodiment, "upstream" refers to the upstream direction in the direction of exhaust flow. "Downstream" refers to the downstream direction in the direction of exhaust flow.

[0012] Components of an Internal Combustion Engine

[0013] As shown in FIG. 1, the internal combustion engine (10) mounted on the vehicle (500) is equipped with a plurality of cylinders (10a). An intake passage (13) is connected to the intake port of each cylinder (10a). A throttle valve (14) for adjusting the intake air volume is provided in the intake passage (13).

[0014] A fuel injection valve (11) is provided in the combustion chamber of each cylinder (10a). In the combustion chamber of each cylinder (10a), a mixture of air and fuel is combusted by ignition through a spark discharge. Air is drawn into the combustion chamber through an intake passage (13). Fuel is injected into the combustion chamber from the fuel injection valve (11). The exhaust generated by the combustion of the mixture in the combustion chamber is discharged through an exhaust passage (15) connected to the exhaust port of the internal combustion engine (10).

[0015] A three-way catalyst (17) is provided in the exhaust passage (15). This three-way catalyst (17) produces water or carbon dioxide by oxidizing hydrocarbons (HC) or carbon monoxide (CO) contained in the exhaust. Additionally, the three-way catalyst (17) produces nitrogen by reducing nitrogen oxides (NOx) contained in the exhaust.

[0016] A gasoline perticulating filter (hereinafter referred to as GPF) (18) is provided in the exhaust passage (15) downstream of the three-way catalyst (17). The GPF (18) is equipped with a filter that captures particulate matter (appropriately referred to as PM) in the exhaust and a three-way catalyst supported by the filter.

[0017] In the exhaust passage (15), a pressure pipe (19) is provided that is connected to the upstream and downstream portions of the exhaust passage (15) for the GPF (18). That is, the exhaust passage (15) is provided with an upstream exhaust section (15a) upstream of the GPF (18) and a downstream exhaust section (15b) downstream of the GPF (18). The pressure pipe (19) is connected to the upstream exhaust section (15a) and the downstream exhaust section (15b). A pressure sensor (50) is provided in the pressure pipe (19). The pressure sensor (50) detects the differential pressure between the upstream exhaust section (15a) and the downstream exhaust section (15b) as a pressure value. That is, the pressure sensor (50) detects the differential pressure between the upstream exhaust pressure and the downstream exhaust pressure of the exhaust passage (15) for the GPF (18). The upstream exhaust pressure is the pressure of the upstream exhaust section (15a), and the downstream exhaust pressure is the pressure of the downstream exhaust section (15b). The pressure sensor (50) outputs the detected pressure value as the pressure sensor value (Ps).

[0018] The control device (100) is equipped with a processing circuit (110). The processing circuit (110) is equipped with a CPU that executes processing according to a program and a memory in which a program or various values ​​are stored. Various controls are performed by the CPU executing a program or program code stored in the memory.

[0019] Detection signals from various sensors are input to the control device (100). As various sensors, for example, a crank angle sensor (53) is provided near the crankshaft of the internal combustion engine (10). Based on the detection signal of the crank angle sensor (53), the engine rotation speed (NE) of the internal combustion engine (10) is calculated. In addition, as various sensors, an air flow meter (54) that detects the intake air volume (GA) and a water temperature sensor (55) that detects the cooling water temperature (THW), which is the temperature of the cooling water of the internal combustion engine (10), are also provided in the internal combustion engine (10).

[0020] The control device (100) performs various controls regarding the GPF (18). Examples of various controls as filter controls include, for instance, regeneration control of the GPF (18) and control for determining abnormal defects in the GPF. An example of filter regeneration control is a control that raises the temperature of the exhaust to burn and remove accumulated PM in the GPF (18) when the pressure value, which is the differential pressure described above, becomes greater than or equal to a predetermined threshold value. An example of control for determining abnormal defects in the GPF is a control that determines that an abnormal defect has occurred in the GPF and notifies a warning when the pressure value, which is the differential pressure described above, becomes less than or equal to another predetermined threshold value.

[0021] <Regarding the process for calculating pressure values>

[0022] FIG. 2 shows the sequence of processing executed by the processing circuit (110) of the control device (100). This processing is repeated at predetermined intervals during one trip from when the main switch of the vehicle (500) is turned ON until it is turned OFF. One trip of the vehicle (500) is from when the main switch of the vehicle (500) is turned ON until it is turned OFF. Also, below, the step number is expressed by a number with "S" assigned to the front.

[0023] In the series of processes shown in FIG. 2, the processing circuit (110) first performs a determination process to determine whether the pressure sensor (50) is normal (S100). That is, the determination process determines whether the pressure sensor (50) is detecting the pressure value (P) normally. In the process of S100, the processing circuit (110) determines whether the pressure sensor (50) is normal, for example, as follows. That is, during the operation of the internal combustion engine (10), the pressure in the exhaust passage (15) fluctuates. Therefore, if the pressure sensor (50) is normal, the pressure sensor value (Ps) fluctuates according to the pressure fluctuation in the exhaust passage (15). The processing circuit (110) determines that the pressure sensor (50) is normal when a fluctuation in the pressure sensor value (Ps) due to the pressure fluctuation in the exhaust passage (15) is detected within a predetermined determination period. Meanwhile, if no change in such pressure sensor value (Ps) is detected, the processing circuit (110) determines that the pressure sensor (50) is not normal.

[0024] In processing S100, if the pressure sensor (50) is determined to be normal (S100: YES), the processing circuit (110) determines whether the conditions for calculating the reference ratio (R) are established (S110). The reference ratio (R) will be described later. In step S110, if the state in which the intake air volume (GA) is greater than or equal to a predetermined threshold value (GAref) continues for a predetermined time (T) or longer, the processing circuit (110) determines that the conditions for calculating the reference ratio (R) are established. The threshold value (GAref) and the predetermined time (T) are pre-set values ​​necessary for properly calculating the reference ratio (R). As for the values ​​of the threshold value (GAref) and the predetermined time (T) necessary for properly calculating the reference ratio (R), for example, values ​​that can determine whether the intake air volume (GA) is in a state of being somewhat large can be used.

[0025] In processing S110, if it is determined that the calculation condition for the reference ratio (R) is established (S110: YES), the processing circuit (110) calculates the average pressure sensor value (Psav) (S120). The average pressure sensor value (Psav) is the average value of the pressure sensor value (Ps) detected by the pressure sensor (50) within a predetermined period (TP).

[0026] Next, the processing circuit (110) calculates a reference pressure (Pref) based on the average intake volume (GAave) (S130). The average intake volume (GAave) is the average value of the intake air volume (GA) detected by the air flow meter (54) within the aforementioned predetermined period (TP). As the intake air volume (GA) increases, the differential pressure between the upstream exhaust pressure and the downstream exhaust pressure for the GPF (18) increases. Therefore, in this embodiment, the intake air volume (GA) is adopted as an operating parameter that influences the pressure value (P), which is the differential pressure.

[0027] The reference pressure (Pref) is a reference value for the pressure value (P). The reference pressure (Pref) is calculated based on the intake air volume (GA), which is an operating parameter involved in the pressure value (P). For example, for a GPF (18) in a state where the PM deposition amount is "0", the correspondence relationship between the intake air volume (GA) and the pressure value (P) is determined in advance. Data or a calculation formula representing the correspondence relationship between the intake air volume (GA) and the pressure value (P) is stored in memory. The processing circuit (110) calculates the reference pressure (Pref) corresponding to the intake air volume (GA) by referring to the data or calculation formula stored in memory. The greater the intake air volume (GA), the larger the value of the reference pressure (Pref).

[0028] Next, the processing circuit (110) calculates a reference ratio (R) (S140). The reference ratio (R) is the ratio of the average pressure sensor value (Psav) to the reference pressure (Pref). That is, R = Psav / Pref. In processing S140, the processing circuit (110) calculates the reference ratio (R) by substituting the value obtained by dividing the average pressure sensor value (Psav) by the reference pressure (Pref) into the reference ratio (R).

[0029] When the amount of PM deposited in the GPF (18) provided in the exhaust passage (15) is "0", the reference ratio (R) becomes the minimum value "1". Meanwhile, even if the intake air volume (GA) is the same, the pressure loss of the GPF (18) increases as the amount of PM deposited in the GPF (18) increases. Therefore, even if the intake air volume (GA) is the same, the pressure sensor value (Ps) of the pressure sensor (50) increases as the amount of PM deposited in the GPF (18) increases. Therefore, as the amount of PM deposited increases and the pressure loss of the GPF (18) increases, the value of the reference ratio (R) increases.

[0030] Next, the processing circuit (110) calculates an average ratio (Rav) (S150). The average ratio (Rav) is the moving average value of the reference ratio (R). That is, the average ratio (Rav) is the value obtained by dividing the sum of the reference ratio (R) calculated in the current processing and the respective reference ratios (R) calculated up to n times of this processing, among the multiple reference ratios (R) calculated at each predetermined period during the trip of the vehicle (500), by (n+1). The value of “n” is a suitable value for calculating the average ratio (Rav).

[0031] When the processing circuit (110) calculates the average ratio (Rav), it stores the calculated average ratio (Rav) in memory (S160). The average ratio (Rav) stored in memory is not used in the current trip of the vehicle (500), but is used in the next trip. In the processing of S160, the average ratio (Rav) is overwritten. Therefore, when the processing of S160 is executed, the value of the average ratio (Rav) stored in memory is updated to the latest value calculated in the current processing of S150.

[0032] In the processing of the above S100, if it is determined that the pressure sensor (50) is not normal (S100: NO), that is, if it is determined that the pressure sensor (50) is not detecting the pressure value (P) normally, the processing circuit (110) performs the initialization of the reference ratio (R) (S170). That is, in the processing of S170, the processing circuit (110) assigns the initial value "0" to both the reference ratio (R) and the average ratio (Rav). The average ratio (Rav) stored in memory retains the current value.

[0033] If the processing of S160 or the processing of S170 is executed, or if a negative determination is made in the processing of S110, the processing circuit (110) terminates the execution of the main processing in this cycle.

[0034] Each of the processes from S120 to S160 above constitutes a reference ratio storage process.

[0035] FIG. 3 shows the sequence of pressure value calculation processing for calculating a pressure value (P). The pressure value calculation processing is executed by the processing circuit (110) of the control device (100). The pressure value calculation processing is executed repeatedly at predetermined intervals during one trip of the vehicle (500). One trip of the vehicle (500) is from when the main switch is turned ON until it is turned OFF.

[0036] In the series of processes shown in FIG. 3, the processing circuit (110) first determines whether the reading of the average ratio (Rav) is completed (S200).

[0037] If it is determined that the reading of the average ratio (Rav) is not completed (S200; NO), the processing circuit (110) reads the value of the average ratio (Rav) (S210). At this time, the value of the average ratio (Rav) read from memory is the value stored in memory as a result of executing the series of processes shown in FIG. 2. In other words, the value of the average ratio (Rav) read from memory is the value calculated during the previous trip of the vehicle (500). More specifically, during the previous trip, the average ratio (Rav) is overwritten. Therefore, the value of the average ratio (Rav) read by the processing circuit (110) during the processing of S210 is the average ratio (Rav) that was last stored during the previous trip. That is, the value of the average ratio (Rav) read during the processing of S210 is the latest value of the average ratio (Rav).

[0038] After executing the processing of S210, or when a positive determination is made in the processing of S200, the processing circuit (110) calculates a reference pressure (Pref) based on the current intake air volume (GA) (S220). The calculation of the reference pressure (Pref) in the processing of S220 is the same as the calculation of the reference pressure (Pref) in the processing of S130. That is, the processing circuit (110) calculates a reference pressure (Pref) corresponding to the intake air volume (GA) by referring to the data stored in memory or the calculation formula.

[0039] Next, the processing circuit (110) calculates the estimated pressure (Pes) (S230). The estimated pressure (Pes) is the calculated value of the pressure value (P). Specifically, the processing circuit (110) multiplies the reference pressure (Pref) calculated in the processing of S220 by the average ratio (Rav) read in the processing of S210. The processing circuit (110) substitutes the value of the product of the multiplication into the estimated pressure (Pes). By doing so, the processing circuit (110) calculates the estimated pressure (Pes).

[0040] Next, the processing circuit (110) substitutes the calculated estimated pressure (Pes) into the pressure value (P) (S240).

[0041] Next, the processing circuit (110) performs the filter control described above based on the pressure value (P) into which the estimated pressure (Pes) is input (S250).

[0042] After that, the processing circuit (110) terminates the execution of the main processing in this cycle.

[0043] <Operations and Effects of the Present Embodiment>

[0044] (1-1) The processing circuit (110) performs a determination process. The determination process determines whether the pressure sensor (50) is normally detecting a pressure value which is the difference pressure between the upstream exhaust pressure and the downstream exhaust pressure for the GPF (18).

[0045] The processing circuit (110) performs a reference ratio storage process. The reference ratio storage process calculates the reference ratio (R) and stores the reference ratio (R) as a value to be used for the next trip of the vehicle (500). The reference ratio (R) is the ratio of the pressure sensor value (Ps) of the pressure value detected by the pressure sensor (50) and the reference pressure (Pref) when it is determined in the judgment process that the pressure sensor (50) is detecting the pressure value normally. The reference pressure (Pref) is calculated based on the driving parameters involved in the pressure value.

[0046] The processing circuit (110) calculates a reference pressure (Pref) based on driving parameters involved in the pressure value during the next vehicle trip for the trip of the vehicle (500) in which the reference ratio (R) is stored. The processing circuit (110) performs a pressure value calculation process to calculate an estimated pressure (Pes), which is the calculated value of the pressure value (P), by multiplying the stored reference ratio (R) by the calculated reference pressure (Pref).

[0047] Accordingly, the reference ratio (R) is calculated based on the pressure sensor value (Ps), which is the pressure value detected by the pressure sensor (50) when it is determined that the pressure sensor (50) is detecting the pressure value normally, and the reference pressure (Pref), which is calculated based on the operating parameters involved in the pressure value.

[0048] The pressure loss of the GPF (18) changes depending on the PM deposition state or amount of PM deposition in the GPF (18). Since the pressure value detected by the pressure sensor (50) changes according to the pressure loss of the GPF (18), the value of the reference ratio (R) depends on the pressure loss of the GPF (18). In a vehicle trip where the reference ratio (R) is calculated, the pressure value (P) during the trip of the vehicle (500) is calculated based on the reference ratio (R) calculated in advance during the previous trip and the reference pressure (Pref) calculated based on the driving parameters involved in the pressure value. That is, in this embodiment, the pressure value (P) during the vehicle trip is calculated using the reference ratio (R) and the reference pressure (Pref). Here, the reference ratio (R) is a value calculated in advance when the pressure sensor (50) detects the pressure value normally. The reference ratio (R) is a value based on the pressure loss of the GPF (18). Therefore, in the next trip for the trip for which the reference ratio (R) was calculated, even if the pressure sensor (50) is in a state where it cannot normally detect the pressure value, a high-precision calculated value of the pressure value (P) can be obtained.

[0049] (1-2) In the process of storing the reference ratio, the reference ratio (R) stored is the moving average value of the reference ratio (R) calculated at a predetermined interval during the trip of the vehicle (500). Therefore, it is possible to store the reference ratio (R) based on the pressure loss of the GPF (18) when the trip of the vehicle (500) ends, after suppressing the deviation of the calculated reference ratio (R).

[0050] (1-3) When the processing circuit (110) determines in the determination process that the pressure sensor (50) is not detecting the pressure value normally, it performs a process to initialize the reference ratio (R) and the average ratio (Rav). The average ratio (Rav) is the moving average value of the reference ratio (R). Therefore, it is possible to prevent the situation where the reference ratio (R) and the average ratio (Rav) are calculated based on an incorrect pressure value.

[0051] (1-4) The reference ratio storage process performs a process to calculate the reference ratio (R) based on the average value of the pressure sensor value (Ps) and the reference pressure (Pref). The pressure sensor value (Ps) is detected by the pressure sensor (50) within a predetermined period (TP). The reference pressure (Pref) is calculated based on the average value of the operating parameters within the predetermined period (TP).

[0052] Therefore, the influence of fluctuations in the pressure sensor value (Ps) detected by the pressure sensor (50) and fluctuations in the operating parameter for calculating the reference pressure (Pref) on the reference ratio (R) can be suppressed.

[0053] (1-5) As the intake air volume (GA) increases, the pressure difference between the upstream exhaust pressure and the downstream exhaust pressure for the GPF (18) increases. Therefore, in this embodiment, the intake air volume (GA) is used as an operating parameter that influences the pressure value. Thus, it is possible to appropriately calculate the reference pressure (Pref).

[0054] FIG. 4 illustrates a second embodiment related to the present disclosure. The second embodiment and the first embodiment differ in that some of the processes shown in FIG. 3 are different. Accordingly, the present embodiment will be described below with an emphasis on such differences.

[0055] FIG. 4 shows the sequence of processing performed by the processing circuit (110) of the present embodiment. For processing identical to that shown in FIG. 3, the same step number is assigned in FIG. 4.

[0056] In the series of processes shown in FIG. 4, the processing circuit (110) calculates the estimated pressure (Pes) by executing each of the processes from S200 to S230 described above.

[0057] When the estimated pressure (Pes) is calculated during the processing of S230, the processing circuit (110) obtains the current pressure sensor value (Ps) of the pressure sensor (50) (S300). The processing of S300 is executed when the pressure sensor (50) detects the pressure value normally. If the pressure sensor (50) does not detect the pressure value normally, the processing circuit (110) substitutes, for example, "0" into the pressure sensor value (Ps).

[0058] Next, the processing circuit (110) determines whether the estimated pressure (Pes) is greater than or equal to the pressure sensor value (Ps) (S310). If it is determined that the estimated pressure (Pes) is greater than or equal to the pressure sensor value (Ps) (S310: YES), the estimated pressure (Pes) is greater than the pressure sensor value (Ps), or the estimated pressure (Pes) is equal to the pressure sensor value (Ps). In this case, the processing circuit (110) assigns the estimated pressure (Pes) to the pressure value (P) (S240).

[0059] Meanwhile, in processing S310, if it is determined that the estimated pressure (Pes) is not greater than or equal to the pressure sensor value (Ps) (S310: NO), the pressure sensor value (Ps) is greater than the estimated pressure (Pes). In this case, the processing circuit (110) substitutes the pressure sensor value (Ps) into the pressure value (P) (S320).

[0060] When either processing of S240 or processing of S320 is executed, the processing circuit (110) subsequently executes processing of S250. In processing of S250, the processing circuit (110) executes the filter control described above based on the pressure value (P) assigned by either processing of S240 or processing of S320.

[0061] After that, the processing circuit (110) terminates the execution of the main processing in this cycle.

[0062] <Operations and Effects of the Present Embodiment>

[0063] According to the present embodiment, in addition to the effects and functions of (1-1), (1-2), (1-3), (1-4), and (1-5) described above, the following effects and functions can be obtained.

[0064] (2-1) The processing circuit (110) performs control of the filter GPF (18) based on the larger of the estimated pressure (Pes) of the pressure value (P) and the pressure sensor value (Ps). The estimated pressure (Pes) of the pressure value (P) is calculated in the pressure value calculation process described above. The pressure sensor value (Ps) is the pressure value (P) detected by the pressure sensor (50).

[0065] Accordingly, when the differential pressure between the upstream exhaust pressure and the downstream exhaust pressure of the GPF (18) becomes unexpectedly high during the trip of the vehicle (500), control regarding the GPF (18) is performed using the higher value between the estimated pressure (Pes) and the pressure sensor value (Ps). The estimated pressure (Pes) is a calculated value of the pressure value (P). Thus, it is possible to cope with an excessively high pressure condition.

[0066] <Change Example>

[0067] Each of the above embodiments may be implemented by modifying it as follows. Each embodiment and the following modifications may be implemented in combination with one another to the extent that they are not technically contradictory.

[0068] · Although a moving average value of the reference ratio (R) was calculated, other average values ​​may be calculated. Furthermore, it is not necessary to calculate such an average value. In that case, other functions and effects other than those described in (1-2) above can be obtained.

[0069] · In the judgment process, if it is determined that the pressure sensor (50) is not detecting the pressure value normally, the initialization process of the reference ratio (R) and average ratio (Rav) is performed, but such initialization is not required. Even in that case, other functions and effects other than those described in (1-3) can be obtained.

[0070] · A reference pressure (Pref) was calculated based on the average value of the driving parameters, and a reference ratio (R) was calculated based on the reference pressure (Pref) and the average pressure sensor value (Psav). The average pressure sensor value (Psav) is the average value of the pressure sensor values ​​(Ps) detected by the pressure sensor (50). However, it is not necessary to calculate such an average value. Even in that case, other functions and effects other than those described in (1-4) can be obtained.

[0071] · As the operating parameter involved in the above pressure value, intake air volume (GA) is used, but other operating parameters may be used.

[0072] · The reference pressure (Pref) is calculated based on the correspondence between the intake air volume (GA) and the pressure value (P) in a GPF (18) where the PM deposition amount is "0". In addition, the correspondence between the intake air volume (GA) and the pressure value (P) in a GPF (18) where the PM deposition amount is a predetermined amount greater than "0" is determined in advance. Data or a calculation formula representing such correspondence is stored in memory. The processing circuit (110) may calculate the reference pressure (Pref) corresponding to the intake air volume (GA) by referring to the data or calculation formula stored in memory. Furthermore, in this modified example, when the PM deposition amount in the GPF (18) is greater than the above-determined amount, the reference ratio (R) becomes a value greater than "1". On the other hand, when the PM deposition amount in the GPF (18) is less than the above-determined amount, the reference ratio (R) becomes a value less than "1".

[0073] · In the processing of S160 shown in FIG. 2, the processing circuit (110) overwrites and stores the calculated average ratio (Rav) in memory. In addition, the processing circuit (110) may not delete the average ratio (Rav) already stored in memory by overwriting the average ratio (Rav) calculated during one trip, but may store all average ratios (Rav) of each trip in memory without deleting them. In this case, the processing circuit (110) may read the average ratio (Rav) that was last stored in the previous trip, that is, the latest value of the average ratio (Rav), when executing the pressure value calculation processing shown in FIG. 3.

[0074] · The placement position of the GPF (18) in the exhaust passage (15) can be appropriately changed.

[0075] ·GPF(18) may be a filter that does not support a three-way catalyst.

[0076] · The control device (100) is not limited to having a CPU and memory to execute software processing. For example, the control device (100) may have a dedicated hardware circuit, such as an ASIC, that performs hardware processing of at least a portion of the software processing in the above embodiment. That is, the control device (100) may include a processing circuit having any of the following configurations (a) to (c). (a) A processing circuit having one or more processing devices that execute all of the above processing according to a program or program code, and one or more program storage devices such as a ROM that store the program or program code. (b) A processing circuit having one or more processing devices and one or more program storage devices that execute a portion of the above processing according to a program or program code, and one or more dedicated hardware circuits that execute the remaining processing. (c) A processing circuit having one or more dedicated hardware circuits that execute all of the above processing. A program storage device, that is, a non-transient computer-readable memory medium, comprises all available media accessible by a general-purpose or dedicated computer.

Claims

Claim 1 As a control device for an internal combustion engine, the control device has a processing circuit, and the processing circuit is a determination process for determining whether a pressure sensor is detecting a pressure value normally, wherein the internal combustion engine is mounted in a vehicle, and a filter for capturing particulate matter in the exhaust of the exhaust passage of the internal combustion engine is provided in the exhaust passage of the internal combustion engine, and a pressure pipe is connected to an upstream part of the exhaust passage with respect to the filter and a downstream part of the exhaust passage with respect to the filter, and the pressure sensor is provided in the pressure pipe and is configured to detect the differential pressure between the pressure of the upstream part and the pressure of the downstream part as the pressure value, the determination process; and a reference ratio storage process for calculating a reference ratio when it is determined in the determination process that the pressure sensor is detecting the pressure value normally, and storing the reference ratio as a value to be used for the next trip of the vehicle, wherein the next trip is a trip of the next time for the vehicle trip in which the reference ratio is stored, and the reference ratio is the ratio of the pressure value detected by the pressure sensor and the reference pressure which is the reference value of the pressure value. A control device for an internal combustion engine configured to execute a pressure value calculation process comprising: a reference ratio storage process in which the reference pressure is calculated based on an operating parameter involved in the pressure value; calculating the reference pressure based on the operating parameter in the next trip; and calculating the pressure value by multiplying the calculated reference pressure by the stored reference ratio. Claim 2 A control device for an internal combustion engine according to claim 1, wherein the reference ratio stored in the reference ratio storage process is the moving average value of the reference ratio calculated at each predetermined period during the trip of the vehicle. Claim 3 A control device for an internal combustion engine according to claim 1 or 2, wherein the processing circuit is configured to initialize the reference ratio when it is determined in the determination process that the pressure sensor is not normally detecting the pressure value. Claim 4 A control device for an internal combustion engine according to any one of claims 1 to 3, wherein the reference ratio storage process calculates the reference ratio based on the reference pressure calculated based on the average value of the pressure value detected by the pressure sensor within a predetermined period and the average value of the driving parameter within the predetermined period. Claim 5 A control device for an internal combustion engine, wherein, in any one of claims 1 to 4, the driving parameter is the intake air volume. Claim 6 A control device for an internal combustion engine according to any one of claims 1 to 5, wherein the processing circuit is configured to perform control regarding the filter based on the larger of the pressure value calculated in the pressure value calculation process and the pressure value detected by the pressure sensor. Claim 7 As a method for controlling an internal combustion engine, the control method determines whether a pressure sensor is detecting a pressure value normally by means of a processing circuit of a control device, wherein the internal combustion engine is mounted in a vehicle, and a filter for capturing particulate matter in the exhaust of the exhaust passage of the internal combustion engine is provided in the exhaust passage of the internal combustion engine, and a pressure pipe is connected to an upstream part of the exhaust passage with respect to the filter and a downstream part of the exhaust passage with respect to the filter, and the pressure sensor is provided in the pressure pipe and is configured to detect the differential pressure between the pressure of the upstream part and the pressure of the downstream part as the pressure value, determining whether the pressure sensor is detecting the pressure value normally; and when it is determined that the pressure sensor is detecting the pressure value normally, the processing circuit calculates a reference ratio, wherein the reference ratio is the ratio of the pressure value detected by the pressure sensor and a reference pressure which is a reference value of the pressure value, and the reference pressure is calculated based on an operating parameter involved in the pressure value, and the reference ratio is calculated for the next trip of the vehicle A control method for an internal combustion engine, comprising storing a value to be used, wherein the next trip is a next trip for a vehicle trip in which the reference ratio is stored, storing the reference ratio; in the next trip, calculating the reference pressure based on the driving parameter by the processing circuit; and calculating the pressure value by multiplying the calculated reference pressure by the stored reference ratio by the processing circuit. Claim 8 A program realized by a non-transient computer-readable storage medium storing program code for executing control processing of an internal combustion engine in a processing device, wherein the control processing determines whether a pressure sensor is detecting a pressure value normally by a processing circuit of the processing device, wherein the internal combustion engine is mounted in a vehicle, and a filter for capturing particulate matter in the exhaust of the exhaust passage of the internal combustion engine is provided in the exhaust passage of the internal combustion engine, and a pressure pipe is connected to an upstream part of the exhaust passage with respect to the filter and a downstream part of the exhaust passage with respect to the filter, and the pressure sensor is provided in the pressure pipe and is configured to detect the differential pressure between the pressure of the upstream part and the pressure of the downstream part as the pressure value, wherein the control processing determines whether the pressure sensor is detecting the pressure value normally, and when it is determined that the pressure sensor is detecting the pressure value normally, a reference ratio is calculated by the processing circuit, wherein the reference ratio is the ratio of the pressure value detected by the pressure sensor to a reference pressure which is a reference value of the pressure value, and the reference pressure is a driving parameter involved in the pressure value A program comprising: calculating the reference ratio calculated based on the above; storing the reference ratio as a value used for the next trip of the vehicle, wherein the next trip is a next trip for the vehicle trip in which the reference ratio is stored; storing the reference ratio, wherein in the next trip, the processing circuit calculates the reference pressure based on the driving parameter; and calculating the pressure value by multiplying the calculated reference pressure by the stored reference ratio by the processing circuit.

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