JP7052669B2 - Engine control unit - Google Patents

Description

The present invention relates to an engine control device that calculates the intake amount of an engine and determines the fuel injection amount based on the calculated value of the intake amount to control the fuel injection of the injector.

In order to properly control the air-fuel ratio (mass ratio of fuel to air) of the air-fuel mixture burned in the cylinder, it is necessary to accurately grasp the intake amount of the engine, that is, the mass of the intake air flowing into the cylinder. Conventionally, three methods of calculating the intake air amount are known: a mass flow method, a speed density method, and a throttle speed method. In the mass flow method, the intake amount is calculated from the intake flow rate detected by the air flow meter installed in the portion upstream of the throttle valve in the intake passage. In the speed density method, the intake pipe pressure is detected by the intake pipe pressure sensor installed in the portion downstream of the throttle valve in the intake passage, and the intake air is taken from the intake air flow rate estimated based on the intake pipe pressure and the engine rotation speed. Calculate the amount. Further, in the throttle speed method, the intake amount is calculated from the intake flow rate estimated based on the throttle opening and the engine speed.

Usually, among these three calculation methods, the mass flow method can calculate the intake amount during steady operation of the engine with the highest accuracy. However, since each cylinder of the engine intermittently sucks intake air according to the opening and closing of the intake valve, the flow of intake air in the intake passage is accompanied by pulsation. And since the effect of such intake pulsation also appears in the detected value of the air flow meter, the speed density method and throttle speed method can calculate the intake amount with higher accuracy than the mass flow method in the operating area of the engine with large intake pulsation. In some cases. On the other hand, conventionally, as seen in Patent Document 1, the intake amount is calculated by the mass flow method when the intake pulsation is small, and the intake amount is calculated by the speed density method or the throttle speed method when the intake pulsation is large. An engine control device that calculates the intake amount while switching the calculation method according to the magnitude of the intake pulsation has been proposed.

Japanese Unexamined Patent Publication No. 2013-22418

In the speed density method and the throttle speed method, the intake air amount is calculated from the estimated intake air flow rate. Therefore, if there is an error in the estimation of the intake air flow rate, the calculated value also has an error. In the above-mentioned conventional engine control device, if such an error occurs when the intake pulsation becomes large, the air-fuel ratio may deviate from the target value and the exhaust performance of the engine may be deteriorated.

The engine control device that solves the above problems calculates the intake amount of the engine, determines the fuel injection amount based on the calculated value of the intake amount, and controls the fuel injection of the injector. Based on either the first intake amount calculation process that calculates the intake amount based on the detected value of the flow rate, the detected value of the intake pipe pressure, or the throttle opening without using the detected value of the same intake flow rate. A second intake amount calculation process for calculating the intake amount and a determination process for determining whether or not the intake pulsation in the intake passage is in a large state are performed.

In the first intake amount calculation process, the intake amount of the mass flow method is calculated based on the detected value of the intake flow rate of the air flow meter. In the second intake amount calculation process, the speed density type intake amount is calculated based on the detected value of the intake pipe pressure, or the throttle speed type intake amount is calculated based on the throttle opening degree. Here, the calculated value of the intake amount by the first intake amount calculation process is defined as the first intake amount, and the calculated value of the intake amount by the second intake amount calculation process is defined as the second intake amount. At this time, the engine control device further performs a deviation amount calculation process and a determination process for calculating the deviation amount of the second intake amount with respect to the first intake amount when it is determined in the determination process that the intake pulsation is not in a large state. When it is determined that the intake pulsation is not large, the first intake amount is set as the calculated value of the intake amount, and when it is determined in the determination process that the intake pulsation is large, the second intake amount is set. The calculation method switching process of setting the corrected second intake amount, which is the sum of the deviation amounts, as the calculation value of the intake amount is performed.

In the above engine control device, when it is determined by the determination process that the intake pulsation is not in a large state (hereinafter referred to as pulsation small determination), the detection accuracy of the intake flow rate of the air flow meter is not lowered and the detection is performed. It is considered that the accuracy of the calculation of the first intake amount in the first intake amount calculation process based on the value is also high. Therefore, in the engine control device, at the time of small pulsation determination, the first intake amount calculated by the mass flow method is calculated as the calculated value of the intake amount. Further, if the first intake amount at this time is an accurate value, the deviation of the second intake amount with respect to the first intake amount becomes an error of the calculated value of the second intake amount. In the engine control device, in the deviation amount calculation process, the deviation amount of the second intake amount with respect to the first intake amount at the time of pulsation small determination is calculated.

On the other hand, when it is determined by the determination process that the intake pulsation is in a large state (hereinafter referred to as pulsation large determination), the detection accuracy of the intake flow rate of the air flow meter is lowered, and the calculation accuracy of the first intake amount is also. descend. At this time, in the engine control device, the corrected second intake amount, which is the sum of the deviation amount calculated at the time of pulsation small determination added to the second intake amount, is calculated as the calculated value of the intake amount. That is, at this time, the value obtained by applying the compensation for the error of the second intake amount confirmed at the time of the small pulsation determination to the second intake amount is calculated as the calculated value of the intake amount. Therefore, according to the engine control device, it is possible to improve the calculation accuracy of the intake air amount in the operating region where the intake air pulsation is large.

Further, in the deviation amount calculation process in the engine control device, the deviation amount learning value, which is the learning value of the deviation amount, is learned by updating the value according to the deviation amount of the second intake amount after correction with respect to the first intake amount. are doing. The deviation amount learning value is reflected in the calculated value of the intake air amount in the pulsation region, which is the engine operating region where the intake air pulsation occurs. The deviation amount between the first intake amount and the second intake amount may differ between the pulsating region and the operating region away from the pulsating region. Therefore, in order to ensure the learning accuracy, it is desirable to limit the operating region for learning the deviation amount learning value to the operating region near the pulsating region. However, in such a case, the learning opportunity is limited, and it may take a long time to complete the learning of the deviation amount learning value.

Therefore, in the deviation amount calculation process in the engine control device, the deviation amount according to the deviation amount in the first learning region including the pulsation region, which is the engine operating region where the intake pulsation occurs before the learning of the deviation amount learning value is completed. The learning value is learned, and after the learning of the deviation amount learning value is completed, the deviation amount learning value is learned according to the deviation amount in the second learning area which is a region including the pulsating region and is narrower than the first learning area. ing. Therefore, before the learning is completed, it is possible to secure a learning opportunity and shorten the time required to complete the learning, and at the same time, it is possible to perform the learning with high accuracy after the learning is completed. Therefore, the deviation amount learning value can be preferably learned.

The deviation amount between the first intake amount and the second intake amount due to the difference in the calculation method may be different depending on the engine speed. In such a case, the deviation amount learning value, the first learning area, and the second learning area are individually set for each of a plurality of rotation speed areas divided according to the engine speed, and the deviation amount learning value is set. Whether or not the learning is completed may be individually determined in each of the plurality of rotation speed ranges.

It can be determined that the learning of the deviation amount learning value is completed if the value is updated until the deviation amount in the pulsation region becomes a sufficiently small value. On the other hand, as described above, the deviation amount between the first intake amount and the second intake amount due to the difference in the calculation method may be different in the operating region near the pulsating region and the operating region separated from the pulsating region. be. Therefore, when it is determined whether or not the learning of the deviation amount learning value is completed in the entire first learning region, the determination is made in the operating region far from the pulsating region, and the deviation amount is sufficiently small in the operating region close to the pulsating region. There is a possibility that it will be judged that the learning is completed in the state where it is not. In that respect, if the completion of learning of the deviation amount learning value is determined based on the deviation amount in the second learning area, the learning of the deviation amount learning value before the completion of learning is performed in the first learning area, but the learning is completed. Can be judged appropriately.

Incidentally, the determination of whether or not the learning is completed can be performed, for example, in the following embodiment. That is, when the engine is being operated in the second learning region, it is determined at each specified determination cycle whether or not the absolute value of the deviation amount is equal to or less than the specified convergence test value. Then, when the number of times that the absolute value of the deviation amount is determined to be equal to or less than the convergence test value is equal to or greater than the specified learning completion determination value, it is determined that the learning of the deviation amount learning value is completed.

The range of the first learning area and the second learning area can be set based on the intake pipe pressure as follows, for example. That is, the first learning region is a region where the intake pipe pressure is equal to or higher than the specified first lower limit value, and the second learning region is a region where the intake pipe pressure is higher than the first lower limit value and is equal to or higher than the second lower limit value.

The schematic which shows typically the structure of the engine control device which becomes the base of 1st Embodiment. The block diagram which shows the flow of the process which concerns on the control of the fuel injection amount executed by the engine control device. A block diagram showing the flow of intake air amount calculation processing executed by the engine control device. The graph which shows the calculation mode of the pulsation rate used in the pulsation determination process by the engine control device. The flowchart of the pulsation determination routine executed by the engine control device at the time of the pulsation determination process. A time chart showing an example of an embodiment of intake air amount calculation processing in the engine control device. The flowchart of the deviation amount learning routine executed by the engine control device of 1st Embodiment. A graph showing the relationship between the update amount and the deviation amount of the deviation amount learning value calculated in the deviation amount learning routine. The graph which shows the setting mode of the deviation amount learning area in the engine control device of the same embodiment. The flowchart of the learning completion determination routine executed by the engine control device of the same embodiment. A time chart showing an example of an embodiment of learning completion determination in the engine control device of the same embodiment. The figure which shows typically the structure of an example of an engine which switches a control mode. The graph which shows the setting mode of the deviation amount learning area using the load factor in the engine which switches a control mode. The graph which shows the setting mode of the deviation amount learning area using the throttle opening in the engine which switches a control mode. The graph which shows the setting mode of the deviation amount learning area using the intake pipe pressure in the engine which switches a control mode.

Here, first, the engine control device which is the basis of the engine control device of the first embodiment will be described. The engine control device of the first embodiment is an improvement of the engine control device (hereinafter referred to as a premise configuration) which is the basis of the engine control device.

As shown in FIG. 1, an air cleaner 12 for filtering dust and the like in the intake air is provided in the most upstream portion of the intake passage 11 of the engine 10 to which the engine control device of the premise configuration is applied. An air flow meter 13 for detecting an intake air flow rate is provided in a portion of the intake passage 11 on the downstream side of the air cleaner 12. Further, a throttle valve 14 which is a valve for adjusting the intake flow rate of the intake passage 11 is provided in a portion of the intake passage 11 on the downstream side of the air flow meter 13. In the vicinity of the throttle valve 14, a throttle motor 15 for driving the opening and closing of the throttle valve 14 and a throttle sensor 16 for detecting the opening degree (throttle opening TA) of the throttle valve 14 are provided. ..

An intake manifold (hereinafter referred to as an intake manifold 17), which is a branch pipe for distributing intake air to each cylinder of the engine 10, is provided in a portion of the intake passage 11 on the downstream side of the throttle valve 14. Each branch pipe of the intake manifold 17 is connected to a combustion chamber 19 of each cylinder via an intake port 18 for each cylinder. The intake port 18 of each cylinder is provided with an injector 20 that injects fuel into the intake air flowing into the combustion chamber 19 through the intake port 18. Further, the combustion chamber 19 of each cylinder is provided with an ignition device 21 for igniting the air-fuel mixture of the fuel flowing into the inside and the intake air by electric discharge. Each cylinder is provided with an intake valve 23 and an exhaust valve 24 that open and close in conjunction with the rotation of the crankshaft 22, which is the output shaft of the engine 10. Then, the intake air flows into the combustion chamber 19 from the intake port 18 according to the opening of the intake valve 23, and the exhaust gas is discharged from the combustion chamber 19 according to the opening of the exhaust valve 24.

The engine 10 is controlled by an electronic control unit 25 as an engine control device. The electronic control unit 25 includes an arithmetic processing circuit 26 that performs various arithmetic processing related to engine control, and a memory 27 that stores control programs and data. In addition to the above-mentioned air flow meter 13 and throttle sensor 16, the electronic control unit 25 includes an intake air temperature sensor 28 that detects the intake air temperature THA, an atmospheric pressure sensor 29 that detects the atmospheric pressure PA, and a rotation angle of the crankshaft 22. Detection signals of various sensors such as the crank angle sensor 30 for detecting (crank angle CRNK) are input. The electronic control unit 25 controls the engine 10 by controlling actuators such as the throttle motor 15, the injector 20, and the ignition device 21 based on the detection signals of the sensors. The electronic control unit 25 calculates the engine speed NE from the detection result of the crank angle CRNK by the crank angle sensor 30.

FIG. 2 shows the flow of processing of the electronic control unit 25 related to the control of the fuel injection amount of the injector 20. When controlling the fuel injection amount, the electronic control unit 25 first determines the engine in the intake amount calculation process P1 based on the AFM detected intake amount GA, throttle opening TA, and engine rotation speed NE, which are the detected values of the intake flow of the airflow meter 13. Calculate the intake amount of 10. The intake amount calculated by the intake amount calculation process P1 (hereinafter, referred to as an intake amount calculation value MC) represents an estimated value of the mass of air to be burned in the combustion chamber 19. Subsequently, in the injection amount determination process P2, the electronic control unit 25 sets the air-fuel ratio of the air-fuel mixture burned in the combustion chamber 19 as a target value based on the intake amount calculation value MC calculated by the intake amount calculation process P1. The fuel injection amount QINJ is determined as described above. Then, the electronic control unit 25 drives the injector 20 of each cylinder so as to inject fuel for the fuel injection amount QINJ in the injector drive process P3.

FIG. 3 shows the flow of processing of the electronic control unit 25 related to the intake amount calculation processing P1. The intake amount calculation process P1 is executed through each of the first intake amount calculation process P4, the second intake amount calculation process P5, the determination process P6, the deviation amount calculation process P7, and the calculation method switching process P8.

In the first intake amount calculation process P4, the intake amount is calculated based on the AFM detected intake amount GA, which is the detected value of the intake flow rate of the air flow meter 13, and the engine rotation speed NE. Specifically, in the first intake amount calculation process P4, the product (= K × GA / NE) obtained by multiplying the quotient obtained by dividing the AFM-detected intake amount GA by the engine speed NE by the specified coefficient K is obtained during steady operation. It is calculated as the value of the intake air amount. Then, the intake amount is calculated as a value that slowly changes while following the intake amount during the steady operation. That is, in the first intake air amount calculation process P4, the intake air amount is calculated by the so-called mass flow method using the detected value of the intake air flow rate of the air flow meter 13. In the following description, the calculated value of the intake amount by the first intake amount calculation process P4 is described as the first intake amount MC1.

In the second intake amount calculation process P5, the intake amount is calculated based on the throttle opening TA and the engine speed NE. Specifically, in the second intake air amount calculation process P5, the intake air flow rate is estimated based on the throttle opening TA and the engine rotation speed NE, and the estimated value of the intake air flow rate (estimated intake air flow rate GA *) is used as the engine rotation speed. The product (= K × GA * / NE) obtained by multiplying the quotient divided by NE by the above coefficient K is obtained as the value of the intake air amount during steady operation. Then, the intake amount is calculated as a value that slowly changes while following the intake amount during the steady operation. That is, in the second intake amount calculation process P5, instead of the detected value of the intake flow of the air flow meter 13, the estimated value of the intake flow based on the throttle opening TA and the engine rotation speed NE is used, that is, the intake by the so-called throttle speed method. A quantity calculation is performed. In the following description, the calculated value of the intake amount by the second intake amount calculation process P5 is described as the second intake amount MC2.

In the determination process P6, it is determined whether or not the intake pulsation in the intake passage 11 is in a large state. The details of the determination process P6 will be described later.
In the deviation amount calculation process P7, when it is determined in the determination process P6 that the intake pulsation is not in a large state (hereinafter referred to as pulsation small determination), the second intake amount MC2 with respect to the first intake amount MC1 Calculate the deviation amount DEV. Specifically, in the deviation amount calculation process P7, the difference obtained by subtracting the second intake amount MC2 from the first intake amount MC1 is obtained at the time of pulsation small determination, and the difference becomes the value after the deviation amount DEV is updated. The value of the deviation amount DEV is updated to. When it is determined in the determination process P6 that the inspiratory pulsation is in a large state (hereinafter referred to as a large pulsation determination), the deviation amount calculation process P7 is not executed and the value of the deviation amount DEV is retained. To.

In the calculation method switching process P8, the first intake amount MC1 is set as the value of the intake amount calculation value MC at the time of pulsation small determination. Further, in the calculation method switching process P8, at the time of determining the large pulsation, the corrected second intake amount MC3 (= MC2 + DEV), which is the sum of the second intake amount MC2 plus the deviation amount DEV, is set as the value of the intake amount calculation value MC. do.

Subsequently, the details of the determination process P6 will be described. As the determination process P6, the maximum value GMAX, the minimum value GMIN, and the average value GAVE of the AFM-detected intake amount GA in the specified period T as shown in FIG. 4 are used. The period T is set to be longer than the cycle of the inspiratory pulsation.

FIG. 5 shows a flowchart of the pulsation determination routine executed in the determination process P6. The processing of this routine is repeatedly executed by the electronic control unit 25 every calculation cycle of the intake air amount during the operation of the engine 10.

When the processing of this routine is started, first, in step S100, the pulsation rate RTE is calculated. The value of the pulsation rate RTE is calculated as the quotient (= (GMAX-GMIN) / GAVE) obtained by dividing the difference obtained by subtracting the minimum value GMIN from the maximum value GMAX of the above-mentioned AFM-detected intake amount GA by the average value GAVE. Subsequently, in step S110, it is determined whether or not the value of the pulsation rate RTE is equal to or greater than the specified pulsation large determination value α.

When the value of the pulsation rate RTE is equal to or higher than the pulsation determination value α (S110: YES), the process proceeds to step S120, and the pulsation large flag F is set in the step S120. Further, in this case, after the value of the counter COUNT is reset to 0 in step S130, the processing of this routine is terminated. The pulsation large flag F is a flag indicating the determination result of the determination process P6, is set at the time of the pulsation large determination, and is cleared at the time of the pulsation small determination. In the above-mentioned deviation amount calculation process P7 and calculation method switching process P8, the determination result of the determination process P6 is confirmed depending on whether or not the pulsation large flag F is set.

On the other hand, when the value of the pulsation rate RTE is less than the pulsation large determination value α (S110: NO), the process proceeds to step S140. Then, in step S140, it is determined whether or not the pulsation large flag F is set. Here, if the large pulsation flag F is not set (S140: NO), the process proceeds to step S130 described above, and after the value of the counter COUNT is reset to 0 in step S130, this routine of this time The process is finished. On the other hand, when the large pulsation flag F is set (S140: YES), the process proceeds to step S150.

When the process proceeds to step S150, the value of the counter COUNT is incremented in step S150. Then, in the subsequent step S160, it is determined whether or not the value of the counter COUNT after the increment is equal to or greater than the specified pulsation off determination value β. If the value of the counter COUNT at this time is less than the pulsation off determination value β (S160: NO), the processing of this routine is terminated as it is. On the other hand, when the value of the counter COUNT is equal to or higher than the pulsation off determination value β (S160: YES), the processing of this routine is terminated after the pulsation large flag F is cleared in step S170.

In the above pulsation judgment routine, the pulsation large flag F is set from the cleared state when the pulsation rate RTE value increases from a value less than the pulsation large judgment value α to a value of the same pulsation large judgment value α or more. It can be switched to the state. Further, the pulsation large flag F is switched from the set state to the cleared state when the pulsation rate RTE is less than the pulsation large determination value α and the counter COUNT value becomes the pulsation determination value β or more. On the other hand, the value of the counter COUNT is incremented when the pulsation rate RTE is less than the pulsation large determination value α and the pulsation large flag F is set, and is reset to 0 in other cases. That is, the increment of the value of the counter COUNT is started when the pulsation rate RTE decreases from the value of the pulsation large judgment value α or more to the value less than the pulsation large judgment value α, and then the pulsation rate RTE is changed to the pulsation large judgment value α. It continues until either the above or the pulsation large flag F is cleared. Then, the value of the counter COUNT at this time is incremented every time the pulsation determination routine is executed, and the pulsation determination routine is further executed every calculation cycle of the intake air amount. Therefore, in the switching from the setting of the pulsation large flag F to the clear, the pulsation rate RTE decreases from the value of the pulsation large judgment value α or more to the value of less than the pulsation large judgment value α, and then the pulsation rate RTE is determined to be the pulsation large judgment value. It is performed when the state where the value is less than the value α continues for a certain period of time.

Subsequently, the operation and effect of the engine control device described above will be described.
FIG. 6 shows an example of an embodiment of the intake air amount calculation process P1 in this engine control device.
In the intake passage 11 of the engine 10, pulsation of intake air is generated by the intermittent opening of the intake valve 23. During high-load operation of the engine 10, such intake pulsation becomes large, and its influence appears in the detection result of the air flow meter 13. Therefore, when the intake pulsation is large, the detection accuracy of the air flow meter 13 is lowered.

On the other hand, the calculation of the intake air amount by the mass flow method is performed based on the detected value of the intake air flow rate of the air flow meter 13 (AFM detected intake air amount GA). Therefore, if the detection accuracy of the air flow meter 13 is lowered in a state where the intake pulsation is large, the calculation accuracy of the intake amount by the mass flow method is also lowered.

On the other hand, in this engine control device, it is determined in the determination process P6 whether or not the intake pulsation is in a large state. The mass flow method is used to calculate the intake amount when the pulsation is small, while the throttle speed method is used to calculate the intake amount when the pulsation is large.

In the case of FIG. 6, the pulsation small determination is made by the determination process P6 until the time t1, and the pulsation large flag F is cleared. Then, at time t1, the determination result of the determination process P6 is switched from the pulsation small determination to the pulsation large determination, and after that time t1, the pulsation large flag F is set. It is considered that the detection accuracy of the air flow meter 13 does not decrease during the small pulsation determination, and the calculation accuracy of the first intake amount MC1 in the first intake amount calculation process P4 is also high. Therefore, in the engine control device of the premise configuration, the first intake amount MC1 is calculated as the value of the intake amount calculation value MC during the pulsation small determination.

Further, assuming that the first intake amount MC1 during the pulsation small determination is an accurate value, the error of the deviation amount DEV of the second intake amount MC2 with respect to the first intake amount MC1 at this time is the error of the second intake amount MC2. It will occur in the calculated value. In the engine control device of the premise configuration, such a deviation amount DEV is calculated during the pulsation small determination in the deviation amount calculation process P7.

On the other hand, when the pulsation small determination is switched to the pulsation large determination, the detection accuracy of the air flow meter 13 is lowered, and the calculation accuracy of the first intake amount MC1 by the first intake amount calculation process P4 is also lowered. At this time, in the engine control device, the corrected second intake amount MC3, which is the sum of the deviation amount DEV calculated at the time of pulsation small determination added to the second intake amount MC2, is calculated as the value of the intake amount calculation value MC. There is. That is, the value compensated for the error of the second intake amount MC2 confirmed from the calculation result of the deviation amount DEV at the time of determining the small pulsation is calculated as the value of the calculated intake amount MC at the time of determining the large pulsation. Therefore, the intake amount calculation value MC can be calculated accurately even when the intake pulsation is large.

Further, if the deviation of the second intake amount MC2 with respect to the first intake amount MC1 is appropriately set as the value of the deviation amount DEV, the deviation amount DEV is set to the first intake amount MC1 and the second intake amount MC2 at time t1. It becomes the same value as the corrected second intake amount MC3 which is the sum of the additions. Therefore, according to the engine control device, it is possible to suppress the occurrence of a step in the value of the intake amount calculation value MC before and after the switching of the calculation method.

(First Embodiment)
Subsequently, the difference between the engine control device of the first embodiment and the premise configuration described above will be described. In the engine control device of the present embodiment, in the deviation amount calculation process P7, the value is on the side where the deviation amount DI becomes smaller based on the deviation amount DI of the corrected second intake amount MC3 with respect to the first intake amount MC1 during engine operation. The deviation amount learning value, which is the learning value of the deviation amount DEV, is learned by updating. Further, in the present embodiment, the learning of the deviation amount learning value is individually learned for each of a plurality of deviation amount learning areas divided according to the engine rotation speed.

FIG. 7 shows a flowchart of the deviation amount learning routine for learning the deviation amount learning value. The processing of this routine is repeatedly executed by the electronic control unit 25 every calculation cycle of the intake air amount during the operation of the engine 10.

When the processing of this routine is started, it is first determined in step S300 whether or not the learning execution condition is satisfied. If the learning execution condition is not satisfied (NO), the processing of this routine is terminated as it is. In this embodiment, (1) the warm-up of the engine 10 has been completed, (2) the operating conditions of the engine 10 have not changed significantly during a transient period, and (3) there are no abnormalities in the sensor or actuator system. It is a requirement for the learning execution conditions to be satisfied that all of the above are satisfied.

When the learning execution condition is satisfied (S300: YES), the process proceeds to step S310, and in step S310, it is determined whether or not the pulsation is small. Specifically, the determination here is made based on the large pulsation flag F in FIG. That is, when the pulsation large flag F is cleared, it is determined that the pulsation is small, and when the pulsation large flag F is set, it is determined that there is no pulsation small determination (when the pulsation is large). The flag. Then, when the pulsation small determination is made (YES), the process proceeds to step S320, and when the pulsation small determination is not made (NO), that is, when the pulsation large determination is made, the processing of this routine is terminated as it is.

In the present embodiment, the operating area of the engine 10 is divided into a plurality of rotation speed ranges according to the engine rotation speed. Then, the deviation amount DEV is individually learned in each of the rotation speed ranges. In this embodiment, a case where five rotation speed ranges are set will be described as an example. Then, in the following description, the five rotation speed ranges are divided into the rotation speed range [1], the rotation speed range [2], the rotation speed range [3], and the rotation speed range [4] in order from the smaller side of the engine rotation speed NE. ] And the rotation speed range [5], respectively. Further, when "i" is any one of 1, 2, 3, 4, and 5, the learning value of the deviation amount DEV corresponding to the rotation speed range [i] is described as the deviation amount learning value DEV [i]. ..

When the process proceeds to step S320, the rotation speed range in which the engine 10 is currently operating is specified in step S320. In the following description, the rotation speed range in which the engine 10 is currently operating is described as the current rotation speed range. Then, in the subsequent step S330, it is determined whether or not the learning completion flag FG [i] corresponding to the current rotation speed range [i] is set. The learning completion flag FG [i] is individually set for each rotation speed range [i], that is, for each deviation amount learning value DEV [i]. Then, the learning completion flag FG [i] is in a set state, and it is cleared that the learning of the deviation amount learning value DEV [i] in the corresponding rotation speed range [i] is completed. It is a flag indicating that the learning of the deviation amount learning value DEV [i] in the corresponding rotation speed range [i] is not completed. The state of the learning completion flag FG [i] is manipulated in the processing of the learning completion determination routine described later.

When the learning completion flag FG [i] in the current rotation speed range is cleared (S330: NO), that is, when the learning of the deviation amount learning value DEV [i] in the current rotation speed range [i] is not completed. Is determined in step S350 whether or not the intake pipe pressure PM is equal to or higher than the specified first lower limit value PMGL. When the intake pipe pressure PM is equal to or higher than the first lower limit value PMGL (YES), the process proceeds to step S360, and when the intake pipe pressure PM is less than the first lower limit value PMGL (NO), the process of this routine is performed as it is. The process is finished. The first lower limit PMGL has a pressure lower than the minimum value of the intake pipe pressure PM in the pulsation region, which is the operating region of the engine 10 in which a large intake pulsation that causes a decrease in the detection accuracy of the air flow meter 13 occurs. It is set as a value.

On the other hand, when the learning completion flag FG [i] in the current rotation speed range is set (S330: YES), that is, the learning of the deviation amount learning value DEV [i] in the current rotation speed range is completed. In this case, in step S340, it is determined whether or not the intake pipe pressure PM is equal to or higher than the specified second lower limit value PMGH. Then, when the intake pipe pressure PM is equal to or higher than the second lower limit value PMGH (YES), the process proceeds to step S360, and when the intake pipe pressure PM is less than the second lower limit value PMGH (NO), this book is used as it is. Routine processing is terminated. The second lower limit value PMGH is set to a pressure lower than the minimum value of the intake pipe pressure PM in the pulsating region and higher than the first lower limit value PMGL.

If the process is advanced to step S360 as a result of the determination in step S340 or step S350, in step S360, the deviation amount learning in the current rotation speed range from the difference between the first intake amount MC1 and the second intake amount MC2. The value obtained by subtracting the value DEV [i] (= MC1-MC2-DEV [i]), that is, the difference between the corrected second intake amount MC3 (= MC2 + DEV [i]) with respect to the first intake amount MC1 is the deviation amount DI. Calculated as a value. Then, in the subsequent step S370, after the deviation amount learning value DEV [i] in the current rotation speed range is updated based on the deviation amount DI, the processing of this routine is terminated. The update amount ΔDEV of the deviation amount learning value DEV [i] at this time is determined by the deviation amount DI and the state of the learning completion flag FG [i].

In FIG. 8, the relationship between the update amount ΔDEV of the deviation amount learning value DEV [i] and the deviation amount DI when the learning completion flag FG [i] is cleared is shown by a solid line. Further, in FIG. 8, the relationship between the update amount ΔDEV of the deviation amount learning value DEV [i] and the deviation amount DI when the learning completion flag FG [i] is set is shown by a dotted line. The value ε shown in the figure is a convergence test value, and is used for determining the learning completion of the deviation amount learning value DEV [i] in the learning completion determination routine.

In the region where the absolute value of the deviation amount DI exceeds the convergence test value ε, the same value is the same regardless of whether the learning completion flag FG [i] is set or cleared, as long as the deviation amount DI value is the same. It is set as the value of the update amount ΔDEV. Specifically, the value of the update amount ΔDEV in this region is set to be as follows. That is, the value of the update amount ΔDEV when the value of the deviation amount DI is gradually increased from the convergence test value ε is set to be a value that increases as the deviation amount DI increases. Further, the value of the update amount ΔDEV when the value of the deviation amount DI is gradually decreased from “−ε” is set so as to be a value that decreases as the deviation amount DI decreases.

On the other hand, in the region where the deviation amount DI exceeds 0 and is "ε" or less, the specified positive value "ζ1" is the learning completion flag when the learning completion flag FG [i] is cleared. When FG [i] is set, “ζ2”, which is a positive value smaller than “ζ1”, is set as the value of the update amount ΔDEV, respectively. Further, in the region where the deviation amount DI is less than 0 and is "-ε" or more, "-ζ1" is set and the learning completion flag FG [i] is set when the learning completion flag FG [i] is cleared. If so, “−ζ2”, which is a negative value larger than “−ζ1” (the absolute value is small), is set as the value of the update amount ΔDEV, respectively. When the deviation amount DI is 0, 0 is set as the value of the update amount ΔDEV regardless of the state of the learning completion flag FG [i].

In the above deviation amount learning routine, the deviation amount learning value DEV [i] is learned by updating the value according to the deviation amount DI of the corrected second intake amount MC3 with respect to the first intake amount MC1 at the time of pulsation small determination. Will be done. Further, in the deviation amount learning routine, the deviation amount learning area, which is the operating area of the engine 10 that learns the deviation amount learning value DEV [i] according to the deviation amount DI at the time of such a small pulsation determination, is the deviation amount learning value DEV [i]. ] Can be switched depending on whether or not learning is completed.

FIG. 9 shows the setting of the deviation amount learning area in the present embodiment. The line L in the figure shows the maximum value of the intake pipe pressure for each engine speed in the operating region of the engine 10. Further, the pulsation region shown by hatching in the figure represents an operating region of the engine 10 in which a large intake pulsation that causes a decrease in the detection accuracy of the air flow meter 13 is generated.

As described above, in the deviation amount learning routine, before the learning of the deviation amount learning value DEV [i] is completed (S330: NO), when the intake pipe pressure PM is equal to or higher than the first lower limit value PMGL (S350: YES). The value of the deviation amount learning value DEV [i] is updated according to the deviation amount DI in steps S360 and S370. On the other hand, after the learning of the deviation amount learning value DEV [i] is completed (S330: YES), when the intake pipe pressure PM is equal to or higher than the second lower limit value PMGH (> PMGL), the steps S360 and S370 are performed. The value of the deviation amount learning value DEV [i] is updated according to the deviation amount DI. Further, the first lower limit value PMGL and the second lower limit value PMGH are set as values lower than the minimum value of the intake pipe pressure PM in the pulsating region. Here, the region where the intake pipe pressure PM in each rotation speed region [i] is equal to or higher than the first lower limit value PMGL is defined as the first learning region in each rotation speed region [i], and the intake pipe pressure in each rotation speed region [i]. The region where PM is equal to or higher than the second lower limit value PMGH is defined as the second learning region in each rotation speed region [i]. In the present embodiment, the learning of the deviation amount learning value DEV [i] according to the deviation amount DI in each rotation speed range [i] includes the pulsating region before the learning of the deviation amount learning value DEV [i] is completed. In the first learning area, after the learning of the deviation amount learning value DEV [i] is completed, the learning is performed in the second learning area, which is the area including the pulsating area and narrower than the first learning area.

FIG. 10 shows a flowchart of the learning completion determination routine. The processing of this routine is repeatedly executed by the electronic control unit 25 at a predetermined determination cycle during the operation of the engine 10.

When the processing of this routine is started, it is first determined in step S400 whether or not the learning completion flag FG [i] in the current rotation speed range [i] is cleared. Then, when the learning completion flag FG [i] is cleared (YES), the process proceeds to step S410, and when the learning completion flag FG [i] is already set (NO), this time as it is. The processing of this routine is terminated.

When the process proceeds to step S410, it is determined in step S410 whether or not the intake pipe pressure PM is equal to or higher than the above-mentioned specified value PMGH. If the intake pipe pressure PM is equal to or higher than the specified value PMGH (YES), the process proceeds to step S420, and if not (NO), the process of this routine is terminated as it is.

When the process proceeds to step S420, it is determined in step S420 whether or not the absolute value of the deviation amount DI is equal to or less than the convergence test value ε. Then, if the absolute value of the deviation amount DI is equal to or less than the convergence test value ε (YES), the process proceeds to step S430, and if not (NO), the process proceeds to step S460.

When the process proceeds to step S430, the determination counter GCNT [i] set for each rotation speed range [i] is counted up in step S430. That is, the value of the determination counter GCNT is updated so that the sum of the value before the update plus 1 is the value after the update. Subsequently, in step S440, it is determined whether or not the determination counter GCNT [i] has a value equal to or higher than the learning completion determination value ι. Then, if the determination counter GCNT [i] is a value equal to or greater than the completion determination value ι (YES), the process proceeds to step S450, and if not (NO), the current process is terminated as it is. If the process is advanced to step S450, the process of this routine is terminated after the learning completion flag FG [i] of the current rotation speed range [i] is set in step S450.

On the other hand, when the process is advanced to step S460, it is determined in step S460 whether or not the absolute value of the deviation amount DI exceeds the deviation determination value η. The deviation determination value η is set to a value larger than the convergence test value ε. Here, if the absolute value of the deviation amount DI exceeds the deviation determination value η (YES), the process proceeds to step S470, and if not (NO), the current process is terminated as it is. If the process is advanced to step S470, the value of the determination counter GCNT [i] is reset to 0 in step S470, and then the process of this routine is terminated.

FIG. 11 shows an example of an embodiment of learning completion determination of the deviation amount learning value DEV [i] by the learning completion determination routine. In the learning of the deviation amount learning value DEV [i], in order to prevent a step in the calculated value of the intake amount when switching the calculation method of the intake amount according to the intake pulsation, the second corrected second with respect to the first intake amount MC1. It is performed so that the deviation amount DI from the intake amount MC3 is sufficiently small. In the present embodiment, in the learning completion determination routine, whether or not the absolute value of the deviation amount DI of the corrected second intake amount MC3 with respect to the first intake amount MC1 is equal to or less than the convergence determination value ε is performed every specified calculation cycle. ing. Then, on condition that the value of the determination counter GCNT [i] indicating the number of times that the absolute value of the deviation amount DI is determined to be equal to or less than the convergence determination value ε is equal to or greater than the learning completion determination value ι or more, the deviation amount learning value DEV It is determined that the learning of [i] is completed.

In the period after the time t1 in the figure, the absolute value of the deviation amount DI of the corrected second intake amount MC3 with respect to the first intake amount MC1 is reduced to the convergence test value ε or less. However, in the present embodiment, the value of the determination counter GCNT [i] is counted up when the absolute value of the deviation amount DI is equal to or less than the convergence test value ε and the intake pipe pressure PM is equal to or more than the second lower limit value PMGH. ing. That is, the count-up of the determination counter GCNT [i] is performed only in the second learning area. Therefore, even if the absolute value of the deviation amount DI is equal to or less than the convergence determination value ε, the period from time t1 to time t2 and the time t3 to time t4 when the intake pipe pressure PM is less than the second lower limit value PMGH. The value of the determination counter GCNT [i] is retained during the period up to. Then, the value of the determination counter GCNT [i] becomes the learning completion determination value ι by counting up when the absolute value of the deviation amount DI is equal to or less than the convergence determination value ε and the intake pipe pressure PM is equal to or more than the second lower limit value PMGH. At the reached time t5, the learning completion flag FG [i] is set assuming that the learning is completed.

As described above, in the present embodiment, when the engine 10 is operated in the second learning region, it is determined at each specified determination cycle whether or not the absolute value of the deviation amount DI is equal to or less than the specified convergence test value ε. The number of times that the absolute value of the deviation amount DI is determined to be equal to or less than the convergence test value ε is recorded as the value of the determination counter GCNT. The deviation amount learning value DEV [ It is determined that the learning of i] is completed. It should be noted that the determination of whether or not the learning of the deviation amount learning value DEV [i] is completed is individually performed in each of the rotation speed regions [i].

The operation and effect of this embodiment will be described.
In the engine control device of the present embodiment, at the time of small pulsation determination, the first intake amount MC1 calculated based on the detection result of the air flow meter 13 by the first intake amount calculation process P4 is calculated as the value of the intake amount calculation value MC. There is. On the other hand, at the time of pulsation large determination in which the detection accuracy of the air flow meter 13 is lowered, the corrected second intake amount MC3 is calculated as the value of the intake amount calculation value MC. The corrected second intake amount MC3 is obtained as the sum of the deviation amount learning value DEV [i] added to the second intake amount MC2 calculated by the second intake amount calculation process P5 without using the detection result of the airflow meter 13. Has been done. Then, the deviation amount learning value DEV [i] is learned by updating the value according to the deviation amount DI of the corrected second intake amount MC3 with respect to the first intake amount MC1 at the time of small pulsation determination.

As described above, the deviation amount learning value DEV [i] is used for the calculation of the intake amount calculation value MC at the time of determining the large pulsation. That is, the deviation amount learning value DEV [i] is reflected in the intake amount calculation value MC only in the high load operation region of the engine 10, which is the pulsation region. On the other hand, since the deviations of the first intake amount MC1 and the second intake amount MC2 due to the difference in the calculation method differ depending on the operating region of the engine 10, the deviation amount learning value DEV [i] is used in the light load operating region and the high load operating region. ] There is a possibility that the learning result will be different. Therefore, in order to ensure the learning accuracy, it is desirable to learn the deviation amount learning value DEV [i] only in the high load operation region. However, the learning of the deviation amount learning value DEV [i] needs to be performed at the time of small pulsation determination, and the learning opportunity is limited only in the high load driving region. Therefore, if the deviation amount learning value DEV [i] is learned only in the second learning area, the time required for the learning to be completed tends to be long.

In that respect, in the present embodiment, before the learning of the deviation amount learning value DEV [i] is completed, the deviation amount learning value DEV [i] is learned in the first learning region including the light load operation region away from the pulsating region. I try to do. Therefore, it is possible to secure learning opportunities and shorten the time required to complete learning. On the other hand, even after the learning is completed, the deviation amount between the first intake amount MC1 and the second intake amount MC2 changes due to changes over time such as the detection characteristic of the air flow meter 13 and the opening characteristic of the throttle valve 14. Since such a change with time progresses slowly over a long period of time, the value of the deviation amount learning value DEV [i] can be made to follow the change even if there are not many learning opportunities. Therefore, in the present embodiment, after the learning is completed, the deviation amount learning value DEV [i] is learned only in the second learning area. As described above, in the present embodiment, as the operating area of the engine 10 for learning the deviation amount learning value DEV [i], a wide area is set in order to secure a learning opportunity before the learning is completed, while after the learning is completed. Sets a narrow area to ensure learning accuracy. Therefore, the deviation amount learning value DEV [i] can be preferably learned.

As described above, the deviation amount between the first intake amount MC1 and the second intake amount MC2 due to the difference in the calculation method differs depending on the operating region of the engine 10, so that the deviation amount DI becomes sufficiently small in the operating region away from the pulsating region. Even so, there may be cases where the deviation amount DI has not yet been sufficiently reduced in the operating region close to the pulsating region. In that respect, in the present embodiment, the deviation amount learning value DEV [i] is learned in the first learning area before the learning is completed, while the learning completion is determined only in the second learning area. While shortening the time required for completion, it is possible to accurately determine the completion of learning.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-In the above embodiment, the case where the deviation amount learning value DEV [i] is individually learned in each of the five rotation speed ranges [i] divided according to the engine rotation speed NE has been described. The number of [i] may be changed as appropriate. Further, a single deviation amount learning value may be used without dividing the rotation speed range.

-In the above embodiment, the calculation of the second intake air amount MC2 in the second intake air amount calculation process P5 is performed by the so-called throttle speed method using the estimated values of the intake air flow rate based on the throttle opening TA and the engine rotation speed NE. rice field. The calculation of the second intake air amount MC2 may be performed by a so-called speed density method using an estimated value of the intake air flow rate based on the detection results of the intake pipe pressure PM and the engine speed NE.

-In the above embodiment, the second lower limit value PMGH is fixed regardless of the engine speed NE. When the intake pipe pressure PM, which is the lower limit of the pulsation region, differs depending on the engine speed NE, the second lower limit value PMGH may be changed for each rotation speed range [i], or as a value that changes depending on the engine speed NE. The second lower limit value PMGH may be set or may be set.

-In the above embodiment, the range of the first learning area and the second learning area is defined by the engine rotation speed NE and the intake pipe pressure PM, but the engine load factor KL and the throttle opening TA may be used. Correlated parameters may be used in place of the intake pipe pressure PM to define the range of the first learning region and the second learning region.

(Second Embodiment)
In some engines such as in-vehicle engines, the control mode of the engine is switched by the manual operation of the driver. In such an engine, the control content of the engine may change depending on the control mode, and as a result, the pulsating region may change. In the present embodiment, a setting mode of the second learning area in the engine for switching the control mode will be described.

FIG. 12 shows a configuration of an example of the engine 100 that switches the control mode. As shown in the figure, the engine 100 includes an exhaust gas recirculation (EGR) system that recirculates a part of the exhaust gas during intake air. The EGR system includes an EGR passage 32 that connects an exhaust passage 31 and a portion of the intake passage 11 downstream of the throttle valve 14 (for example, the intake manifold 17). The EGR passage 32 includes an EGR cooler 33 that cools the exhaust gas (EGR gas) recirculated during intake through the EGR passage 32, and an EGR valve 34 that is a flow rate adjusting valve for adjusting the flow rate of the EGR gas. And are provided. Further, the engine 10 is provided with a variable valve mechanism 35 that changes the valve timing (off-off valve timing) of the intake valve 23.

In the engine 100, a fuel consumption mode and a power mode can be selected as the control mode of the engine 100 by operating a switch provided in the driver's seat. The fuel consumption mode is a control mode for improving the fuel consumption of the engine 100 by introducing a large amount of EGR gas even during high load operation. On the other hand, the power mode is a control mode in which the maximum output of the engine 100 is increased by suppressing the amount of EGR gas introduced during high-load operation and increasing the amount of air introduced into the combustion chamber 19 by that amount. It has become.

In the power mode, the variable valve mechanism 35 is controlled so that the valve closing timing of the intake valve 23 is later than the intake bottom dead center during high load operation. Assuming that the valve closing time of the intake valve 23 is later than the intake bottom dead center, a part of the intake air introduced into the combustion chamber 19 during the period from the intake bottom dead center to the closing of the intake valve 23 is in the intake passage 11. It is pushed back, and the intake pipe pressure PM increases accordingly. Therefore, in the fuel consumption mode, in order to secure the intake negative pressure required for mass introduction of EGR gas, the variable valve timing is such that the valve closing time of the intake valve 23 during high load operation is earlier than that in the power mode. It controls the mechanism 35.

In such an engine 100, the opening degree of the EGR valve 34 and the valve timing of the intake valve 23 are also factors that determine the intake amount. Therefore, in the first intake amount calculation process P4 when applied to the engine 100, in addition to the AFM detected intake amount GA and the engine rotation speed NE, the first is based on the opening degree of the EGR valve 34 and the valve timing of the intake valve 23. 1 It is advisable to calculate the intake amount MC1. Further, in the second intake amount calculation process P5, the second intake amount MC2 may be calculated based on the opening degree of the EGR valve 34 and the valve timing of the intake valve 23 in addition to the throttle opening TA and the engine rotation speed NE.

Also in this embodiment, as in the case of the first embodiment, the deviation amount learning value DEV [i] is learned according to the deviation amount DI of the corrected second intake amount MC2 with respect to the first intake amount MC1 at the time of pulsation small determination. At the time of determining the large pulsation, the intake amount is calculated using the deviation amount learning value DEV [i]. Further, the driving area for learning the deviation amount learning value DEV [i] is switched from the first learning area to the second learning area according to the completion of learning.

As described above, as the index value of the engine load that defines the range of the second learning region, it is possible to use the engine load factor KL and the throttle opening TA in addition to the intake pipe pressure PM. However, in the case of the engine 100 that switches the control mode as described above, it is necessary to consider the change in the pulsating region due to the control mode when setting the range of the second learning region. In the following description, one of the intake pipe pressure PM, the engine load factor KL, and the throttle opening TA is used as the index value of the engine load, and the index value of the engine load and the engine rotation speed NE are used as the coordinate axes. The line showing the relationship between the lower limit of the index value of the engine load in the pulsating region and the engine rotation speed NE when the range of the pulsating region is drawn in the system is described as the pulsating region boundary line. Further, a line showing the relationship between the lower limit of the index value of the engine load and the engine speed NE in the second learning region when the range of the second learning region is drawn in the orthogonal coordinate system is described as a learning switching line. ..

Here, first, in the engine 100 for switching the control mode, a case where the range of the second learning region is defined by using the engine load factor KL will be described.
The decrease in the detection accuracy of the air flow meter 13 due to the intake pulsation is due to the pressure fluctuation in the intake port 18 caused by the intermittent inflow of gas (intake + EGR gas) into the combustion chamber 19 according to the opening and closing of the intake valve 23. It is generated by running up the intake passage 11 to the installation location of 13. If the engine speed NE is the same, the pressure fluctuation in the intake port 18 increases as the flow rate of the gas flowing through the intake port 18 (hereinafter referred to as the port flow rate) increases. On the other hand, the port flow rate when the engine speed NE and the engine load factor KL are constant is larger in the fuel consumption mode than in the power mode due to the larger amount of EGR gas introduced. Therefore, the lower limit of the engine load factor KL in the pulsation region when the engine speed NE is constant is smaller in the fuel consumption mode than in the power mode. On the other hand, the second learning region needs to be set to be a high load operation region near the pulsating region. Therefore, in the engine 100 that switches the control mode as described above, when the second learning area is defined by using the engine load factor KL, the second learning area is changed according to the change of the pulsating area due to the control mode. The range also needs to be switched according to the control mode. In FIG. 13, the pulsating region boundary lines L1 and L2 in the power mode and the fuel consumption mode in this case, and the learning switching lines L3 in the power mode and the fuel consumption mode when the second learning region is set according to them are shown. An example of the setting mode of L4 is shown.

Subsequently, in the engine 100 for switching the control mode, a case where the range of the second learning region is defined by using the throttle opening TA will be described. When the engine speed NE and the throttle opening TA are constant, the port flow rate is larger in the fuel consumption mode than in the power mode due to the larger amount of EGR gas introduced. Therefore, the lower limit of the throttle opening TA in the pulsation region when the engine speed NE is constant is smaller in the fuel consumption mode than in the power mode. Therefore, also in this case, it is necessary to switch the range of the second learning region according to the control mode according to the change of the pulsating region depending on the control mode. FIG. 14 shows the pulsating region boundary lines L5 and L6 in the power mode and the fuel consumption mode in this case, and the learning switching lines L7 in the power mode and the fuel consumption mode when the second learning area is set accordingly. , An example of the setting mode of L8 is shown.

Finally, in the engine 100 for switching the control mode, a case where the range of the second learning region is defined by using the intake pipe pressure PM will be described. Since the port flow rate is almost uniquely determined by the engine speed NE and the intake pipe pressure PM, the relationship between the intake pipe pressure PM, which is the lower limit of the pulsating region, and the engine speed NE does not change even if the control mode is changed. .. Therefore, in this case, it is not necessary to switch the range of the second learning area by the control mode. That is, when the operating region of the engine 100 is defined by the engine speed NE and the intake pipe pressure PM, the range of the pulsating region is the same in both the power mode and the fuel consumption mode. A common range can be set as a learning area. FIG. 15 shows an example of the setting mode of the pulsating region boundary line L9 in this case and the learning switching line L10 when the second learning region is set according to the pulsating region boundary line L9. As shown in the figure, in this case, the pulsating region boundary line L9 and the learning switching line L10 in both the power mode and the fuel consumption mode control modes are common.

10,100 ... engine, 11 ... intake passage, 12 ... air cleaner, 13 ... airflow meter, 14 ... throttle valve, 15 ... throttle motor, 16 ... throttle sensor, 17 ... intake manifold, 18 ... intake port, 19 ... combustion chamber, 20 ... Injector, 21 ... Ignition plug, 22 ... Crank shaft, 23 ... Intake valve, 24 ... Exhaust valve, 25 ... Electronic control unit (engine control device), 26 ... Arithmetic processing circuit, 27 ... Memory, 28 ... Intake temperature sensor , 29 ... atmospheric pressure sensor, 30 ... crank angle sensor, 31 ... exhaust passage, 32 ... EGR passage, 33 ... EGR cooler, 34 ... EGR valve, 35 ... variable valve mechanism, P1 ... intake amount calculation processing, P2 ... injection Amount determination processing, P3 ... Injector drive processing, P4 ... First intake amount calculation processing, P5 ... Second intake amount calculation processing, P6 ... Judgment processing, P7 ... Deviation amount calculation processing, P8 ... Calculation method switching processing.

Claims (5)

In an engine control device that calculates the intake amount of the engine and determines the fuel injection amount based on the calculated value of the same intake amount to control the fuel injection of the injector.
The first intake amount calculation process that calculates the intake amount based on the detected value of the intake flow rate of the air flow meter,
A second intake amount calculation process for calculating the intake amount based on either the detection value of the intake pipe pressure or the throttle opening without using the detection value of the intake flow rate.
Judgment processing for determining whether or not the intake pulsation in the intake passage of the engine is large, and
When the calculated value of the intake amount by the first intake amount calculation process is set as the first intake amount and the calculated value of the intake amount by the second intake amount calculation process is set as the second intake amount, the determination process is performed. A deviation amount calculation process for calculating the deviation amount of the second intake amount with respect to the first intake amount when it is determined that the intake pulsation is not in a large state.
When it is determined in the determination process that the inspiratory pulsation is not in a large state, the first inspiratory amount is set as a calculated value of the inspiratory amount, and it is determined in the determination process that the inspiratory pulsation is in a large state. When, the calculation method switching process for setting the corrected second intake amount, which is the sum of the second intake amount and the deviation amount, as the calculation value of the intake amount, and
And
Further, in the deviation amount calculation process, the deviation amount learning value, which is the learning value of the deviation amount, is learned by updating the value according to the deviation amount of the corrected second intake amount with respect to the first intake amount. Before the learning of the deviation amount learning value is completed, the deviation amount learning value is learned according to the deviation amount in the first learning region including the pulsation region which is the engine operating region where the intake pulsation is generated, and the deviation amount learning value is learned. An engine control device that learns the deviation amount learning value according to the deviation amount in a second learning area which is a region including the pulsation region and is narrower than the first learning region after the learning of the deviation amount learning value is completed. The deviation amount learning value, the first learning area, and the second learning area are individually set for each of a plurality of rotation speed regions divided according to the engine rotation speed.
The engine control device according to claim 1, wherein the presence or absence of learning of the deviation amount learning value is individually determined in each of the plurality of rotation speed ranges. The engine control device according to claim 1 or 2, wherein the completion of learning of the deviation amount learning value is determined based on the deviation amount in the second learning region. When the engine is being operated in the second learning region, it is determined at each specified determination cycle whether or not the absolute value of the deviation amount is equal to or less than the specified convergence test value.
In claim 3, when the number of times that the absolute value of the deviation amount is determined to be equal to or less than the convergence determination value is equal to or greater than the specified learning completion determination value, it is determined that the learning of the deviation amount learning value is completed. The engine control device described. The first learning region is a region where the intake pipe pressure is equal to or higher than the specified first lower limit value, and the second learning region is a region where the intake pipe pressure is higher than the first lower limit value and is equal to or higher than the second lower limit value. The engine control device according to any one of claims 1 to 4, which is an area.

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