JP4452230B2 - Device for controlling the amount of intake air into an internal combustion engine - Google Patents

Description

  The present invention relates to an apparatus for controlling the amount of intake air to an internal combustion engine in accordance with the degree of carbon clogging in a throttle of an intake pipe.

  In an intake system of an internal combustion engine, it is known that a lubricating oil component or a combustion product adheres to a throttle valve due to long-term use, and a so-called carbon clogging (deposit) is generated. When carbon clogging occurs, the opening area of the throttle valve decreases, so the amount of intake air with respect to the throttle opening decreases.

Patent Document 1 describes a method of correcting the throttle valve opening in accordance with the influence of the amount of carbon clogging. According to this method, the clogging coefficient representing the degree of clogging of the intake pipe is calculated based on the feedback correction amount for controlling the rotational speed of the internal combustion engine. The throttle valve opening is corrected based on the clogging coefficient.
JP 2005-76595 A

  According to the conventional method, the clogging coefficient calculated based on the feedback correction amount includes the influence of friction such as the internal combustion engine and the auxiliary machine load in addition to the degree of clogging of the intake pipe. Therefore, when the friction changes due to variations in the internal combustion engine and the auxiliary machine load, there is a possibility that the clogging coefficient indicating the degree of clogging of the intake pipe may not be accurately calculated.

  An object of the present invention is to provide an intake air amount control device that can accurately detect a clogging coefficient representing the degree of clogging of an intake pipe without being affected by friction of an internal combustion engine or an auxiliary machine.

  The present invention provides an apparatus for detecting the degree of clogging of an intake pipe based on a disturbance component identified from an intake pipe model and controlling the amount of intake air to the internal combustion engine. This device models an intake air amount detection means for detecting an intake air amount, a throttle valve opening degree detection means for detecting an opening degree of a throttle valve provided in the internal combustion engine, and an intake pipe of the internal combustion engine. An identifying means for identifying the component; and a clogging coefficient calculating means for calculating a clogging coefficient representing the degree of clogging of the intake pipe of the internal combustion engine based on the identified disturbance component. This device adjusts the opening of the throttle valve based on the clogging coefficient.

  According to the present invention, disturbance components such as carbon clogging applied to the intake pipe are identified, and a clogging coefficient is calculated based on the identified disturbance components. Therefore, even if the friction changes due to variations in the internal combustion engine and auxiliary equipment load, the clogging coefficient representing the degree of clogging of the intake pipe can be accurately detected.

  According to an embodiment of the present invention, the apparatus includes a correction unit that corrects the identified disturbance component based on the operating environment of the internal combustion engine, and an identification that represents a deviation between the corrected disturbance component and the reference value. And a means for obtaining a parameter. The clogging coefficient calculating means calculates the clogging coefficient based on the identification parameter. As a result, the disturbance component identified by the identification means is corrected so as not to fluctuate due to changes in atmospheric pressure or intake air temperature, so that the clogging coefficient representing the degree of clogging of the intake pipe can be accurately detected.

  Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an idle speed control device for an internal combustion engine. The engine 10 is, for example, a 4-cylinder automobile engine.

  A throttle valve 14 is disposed in the intake pipe 12. The throttle valve 14 is driven by an actuator 18 in response to a control signal from an electronic control unit (hereinafter referred to as “ECU”) 60. The ECU 60 sends a control signal for controlling the opening of the throttle valve 14 to the actuator 18 in accordance with an output from an accelerator pedal opening sensor (not shown). This method is called a drive-by-wire method (hereinafter referred to as “DBW”). In the control of the DBW throttle valve, when the accelerator pedal opening is 0, the ECU controls the actuator 18 so that the throttle opening is such that the intake air quantity can be obtained so that the engine can maintain the idling speed. Send a signal.

  A throttle valve opening sensor 20 is provided near the throttle valve 14 and outputs a signal corresponding to the throttle opening θTH.

  Alternatively, a mechanical throttle valve may be used instead of the DBW throttle valve 14. The throttle valve has a wire 16 connected to an accelerator pedal, and the opening degree is directly controlled by the accelerator pedal. In this case, a passage (not shown) that bypasses the throttle valve is provided, and an electromagnetic valve (not shown) that is driven to open and close according to a control signal from the ECU 60 is provided in the bypass passage. When the engine is in an idle state, the throttle valve is fully closed, and the amount of intake air to the engine can be adjusted by controlling the opening of the electromagnetic valve.

  A fuel injection valve 24 is provided for each cylinder between the throttle valve 14 and the intake valve of the engine 10. The fuel injection valve 24 is connected to a fuel pump (not shown) and receives fuel from a fuel tank (not shown) via the fuel pump. The fuel injection valve 24 is driven according to a control signal from the ECU 60.

  An air flow meter 17 is installed upstream of the throttle valve 14 in the intake pipe 12. The air flow meter 17 outputs an electric signal indicating the intake air amount to the ECU 60.

  An intake pipe pressure sensor 32 and an intake temperature sensor 34 are provided downstream of the throttle valve 14 in the intake pipe 12 and output electrical signals indicating the intake pipe absolute pressure PB and the intake temperature TA, respectively.

  A cylinder discrimination sensor (CYL) 40 is provided in the vicinity of the camshaft or crankshaft of the engine 10 and outputs, for example, a cylinder discrimination signal CYL at a predetermined crank angle position of the first cylinder. Further, a TDC sensor 42 and a crank angle sensor (CRK) 44 are provided, and the former outputs a TDC signal at a predetermined crank angle position related to the piston top dead center (TDC) position of each cylinder. The CRK signal is output at a crank angle (for example, 30 degrees) having a shorter cycle than the TDC signal.

  An exhaust pipe 46 is connected to the engine 10. The exhaust gas generated by the combustion is purified by the catalyst device 50 and discharged to the outside. A wide area air-fuel ratio (LAF) sensor 52 is provided upstream of the catalyst device 50 and outputs a signal proportional to the oxygen concentration in the exhaust gas in a wide range from lean to rich.

  A vehicle speed sensor 54 is disposed in the vicinity of the drive shaft that drives the wheels of the automobile, and outputs a signal every predetermined rotation of the drive shaft. The vehicle is provided with an atmospheric pressure sensor 56 and outputs a signal corresponding to the atmospheric pressure.

  Outputs of these sensors are sent to an ECU (electronic control unit) 60. The ECU 60 is constituted by a microcomputer, and includes a processor CPU 60a that performs calculations, a list of control programs and various data, a ROM 60b that stores tables, and a RAM 60c that temporarily stores calculation results by the CPU 60a. Outputs of various sensors are input to an input interface 60d of the ECU 60. The input interface 60d includes a circuit that shapes an input signal and corrects a voltage level, and an A / D converter that converts an analog signal into a digital signal.

  The CPU 60a counts the CRK signal from the crank angle sensor 44 with a counter to detect the engine speed NE, and also counts the signal from the vehicle speed sensor 54 to detect the vehicle running speed VP. The CPU 60a executes calculation according to a program stored in the ROM 60b, and sends a drive signal to the fuel injection valve 24, the throttle valve / actuator 18 and the like via the output interface 60e.

  FIG. 2 is a functional block diagram of the intake air amount control device according to one embodiment of the present invention.

  The feedback control unit 71 performs feedback control that controls the opening of the throttle valve so that the engine speed converges to the target speed during idle operation. The feedback control unit 71 calculates a control amount ICMDTH for controlling the opening degree of the throttle valve. This calculation is performed according to the equation (1), for example.

ICMDTH = (IFB + ILOAD) x KIPA + IPA (1)
Here, IFB is a correction term set so that the engine speed matches the target speed, and is calculated using a conventional feedback control method such as PID control, for example. ILOAD is an electric load applied to the engine, a compressor load of the air conditioner, a power steering load, and a load correction term set in accordance with whether the automatic transmission is in gear. KIPA and IPA are a correction coefficient and a correction term set according to the atmospheric pressure, respectively.

  The disturbance identification unit 72 calculates an identification value DFIL representing the influence of disturbance components such as carbon clogging based on the model of the intake pipe 12 that estimates the current intake air amount from the past intake air amount and the past throttle opening. To do. The identification value DFIL is a parameter for expressing a decrease in the intake air amount due to the influence of the disturbance component in the intake pipe model, and takes a negative value corresponding to the disturbance component. The identification value DFIL is updated so as to increase in the negative direction as the influence of the disturbance component increases, and works so that the intake pipe model estimates the intake air amount to be small. In the present embodiment, the disturbance identification unit 72 is an adaptive disturbance observer that identifies disturbance components using a sequential identification algorithm. Details of the processing in the disturbance identification unit 72 will be described later with reference to FIGS.

  The identification value correction unit 73 corrects the identification value according to the environmental conditions. When environmental conditions such as atmospheric pressure and intake air temperature are different, the volumetric efficiency changes, so that the correlation between the intake air amount and the throttle opening is broken. For this reason, the identification value DFIL calculated by the disturbance identification unit 72 based on the intake air amount and the throttle opening varies depending on the environmental conditions. Since the identification value DFIL is a parameter that represents the degree of clogging of the intake pipe due to carbon clogging or the like, it is desirable that the identification value DFIL does not change depending on the external environment. Therefore, in the present embodiment, the identification value DFIL is corrected using the environmental correction coefficient according to the atmospheric pressure and the intake air temperature, and the corrected identification value DTAPA is calculated.

  The identification parameter calculation unit 74 calculates the identification parameter DFTHF from the identification value DTAPA corrected by the identification value correction unit 73. The identification parameter DFTHF represents the degree of clogging of the intake pipe.

  Details of the processes in the identification value correction unit 73 and the identification parameter calculation unit 74 will be described later with reference to FIGS.

  The clogging coefficient calculation unit 75 calculates the clogging coefficient KTHC based on the identification parameter DFTHF. The clogging coefficient KTHC indicates how much the intake pipe is clogged. The larger the clogging coefficient KTHC, the worse the clogging. In the present embodiment, the clogging coefficient KTHC is calculated so that the difference from the clogging coefficient KTHC calculated in the previous operation cycle is within a predetermined range. Details of the processing in the clogging coefficient calculation unit 75 will be described later with reference to FIG.

  The throttle opening calculation unit 76 calculates the target throttle opening THICMD based on the control amount ICMDTH and the clogging coefficient KTHC. The opening degree of the throttle valve is controlled so as to converge to the target throttle opening degree THICMD. Thus, the throttle valve is controlled to an opening degree corresponding to the clogging of the intake pipe. The greater the clogging, the larger the opening of the throttle valve so that a desired amount of air is drawn into the engine. Details of the processing in the throttle opening calculation unit 76 will be described later with reference to FIG.

  Next, a method for calculating the target throttle opening degree THICMD will be described with reference to FIG.

  FIG. 3 is a map showing the throttle opening THICMD to be set with respect to the air amount ICMDTH to be taken into the engine. Reference numeral 81 indicates a throttle characteristic when the intake pipe is not clogged. Reference numeral 83 indicates a throttle characteristic when it is determined that the throttle valve is in a clogged limit that can be controlled.

  The throttle opening calculation unit 76 refers to the map based on the control amount ICMDTH calculated by the feedback control unit 71.

  The target throttle opening at which the throttle valve opening is actually controlled needs to be calculated in consideration of not only clogging but also other factors. Therefore, as shown in the above-described equation (1), the map is referred to based on the control amount ICMDTH calculated in consideration of the engine load and the like.

  Based on the throttle characteristics 81 and 83, an upper limit value THICMDC and a lower limit value THICMDX corresponding to the control amount ICMDTH are calculated. By using the clogging coefficient KTHC calculated by the clogging coefficient calculation unit 75, the target throttle opening degree THICMD corresponding to the clogging coefficient can be calculated by proportional calculation based on the upper limit value THICMDC and the lower limit value THICMDX. A detailed calculation formula will be described later with reference to FIG.

  Next, processing for calculating the identification value DFIL of the disturbance component of the intake pipe in the disturbance identification unit 72 will be described with reference to FIGS. This process is executed every predetermined time step (for example, 10 msec).

  FIG. 4 is a main flow of processing for calculating the identification value DFIL.

  In step S101, it is confirmed whether the engine is in an idle operation state. If it is during idling, the process proceeds to step S103 and the process is continued. If it is other than the idling operation, the process proceeds to step S107, and the identification value is not calculated in the current process and the previous identification value is held and the process is terminated.

  In step S103, an intake pipe model identification error EIDIPC is calculated. This process will be described later with reference to the subroutine of FIG.

  In step S105, among the past identification values DFIL stored in the buffer, the past identification value DFILZ is the one before N steps. Here, “N steps before” means, for example, 5 steps before and 50 ms in real time.

  In step S111, an update coefficient KPIPC for identification processing is calculated. This process will be described later with reference to the subroutine of FIG.

  In step S113, the identification error EIDIPC is multiplied by the update coefficient KPIPC to calculate an update component DDIPC for the identification process.

  In step S117, the past identification value DFILZ is added to the update component DDIPC to calculate the raw identification value DIPC.

  In step S119, the average value of the previous raw identification value DIPCZ and the raw identification value DIPC calculated in step S117 is obtained, and the identification value DFIL is calculated.

  FIG. 5 is a flowchart showing a process for calculating the identification error EDIPC of the intake pipe model. This process shows the details of the process in step S103 of FIG.

  In step S123, among past identification values DFIL stored in the buffer, the previous identification value DIPCFZ is set to be N steps before. Here, “N steps before” means, for example, 5 steps before and 50 ms in real time.

  In step S127, the current intake air amount gb0 (g / sec) is calculated from the measured value of the current air flow meter (AFM).

  In step S129, the intake air amount gb1 (g / sec) before N steps is calculated from the measured value of the air flow meter before N steps. Here, “N steps before” means, for example, 5 steps before and 50 ms in real time.

  In step S131, the intake air amount gb2 (g / sec) before the 2N step is calculated from the measured value of the air flow meter before the 2N step. Here, 2N steps ago is, for example, 10 steps ago, and is 100 msec ago in real time.

  In step S133, the throttle opening th2 (deg) before 2N steps is calculated from the measured value of the throttle opening sensor before 2N steps.

  In step S135, an estimated intake air amount GHATF is calculated. This calculation is performed using, for example, a model expression of the intake pipe 12 shown in Expression (2).

GHATF = A1 x gb1 + A2 x gb2 + B2 x th2 + DIPCFZ (2)
Here, gb1 represents the intake air amount before N steps calculated in step S129, and gb2 represents the intake air amount before 2N steps calculated in step S131. th2 represents the throttle opening 2N steps before calculated in step S133. A1, A2, and B2 are arbitrary constants. DIPCFZ is a past identification value before N steps obtained in step S123.

  Thus, the intake pipe model shown in equation (2) is based on the past values of actual intake air amount (gb1, gb2), the past value of throttle opening (th2), and the past value of disturbance identification value (DIPCFZ). Estimate the current intake air amount GHATF.

  In step S137, an intake pipe model identification error EIDIPC is calculated. The identification error EIDIPC is obtained by subtracting the estimated intake air amount GHATF calculated in step S135 from the current actual intake air amount gb0 calculated in step S127. When the throttle valve is clogged, the actual intake air amount becomes smaller than the estimated intake air amount, so the identification error EIDIPC takes a negative value.

  FIG. 6 is a flowchart showing a process for calculating the update coefficient KPIPC of the identification process. This process shows details of the process in step S111 of FIG.

  In step S141, an error DGTM between the current measured value GTM of the air flow meter and the target value GCIPCF is calculated.

  In step S143, the gain PDIPC is calculated by referring to the map based on the error DGTM. FIG. 7 shows an example of the map. The horizontal axis of the graph represents the error DGTM, and the vertical axis represents the corresponding gain PDIPC. Referring to FIG. 7, the gain PDIPC is set larger as the error DGTM is larger. Due to the action of the gain PDIPC, the larger the error DGTM, the faster the identification update speed, and the smaller the error DGTM.

  In step S145, the current intake air amount g1 (g / sec) is calculated from the measured value of the current air flow meter.

  In step S147, the previous intake air amount g2 (g / sec) is calculated from the measured value of the air flow meter one step before (for example, 10 msec).

  In step S149, the calculated intake air amount is subjected to a high-pass filter process. This process is performed according to, for example, the expression (3).

HFG = GA1 x g1 + GA2 x g2 + GB2 x HFG (previous value) (3)
Here, HFG is the amount of intake air that has been subjected to high-pass filtering, and represents an instantaneous variation in the amount of intake air. g1 is the current intake air amount, and g2 is the previous intake air amount. GA1, GA2, and GB2 are arbitrary constants.

  In step S151, it is confirmed whether or not the absolute value | HFG | of the intake air amount subjected to the high-pass filter process is larger than a predetermined threshold value. If the absolute value | HFG | is larger than the threshold value, the process proceeds to step S153, and 1.0 is assigned to the coefficient KPDIPC. If the absolute value | HFG | is equal to or smaller than the predetermined value, the process proceeds to step S155, and a predetermined value (for example, 0.1) is substituted for the coefficient KPDIPC. By this process, when the fluctuation of the intake air amount is large, the update speed is slowed by setting the coefficient KPDIPC small, and the sudden fluctuation of the identification value DFIL is suppressed.

  In step S157, the gain PDIPC calculated in step S143 is multiplied by the coefficient KPDIPC to calculate PDIPCF, and in step S159, the PDIPCF is normalized to calculate the update coefficient KPIPC. Normalization is performed, for example, according to equation (4).

KPIPC = PDIPCF / (1.0 + PDIPCF) (4)
Here, 0 <KPIPC <1.

  Next, a process for calculating the identification parameter DFTHF in the identification value correction unit 73 and the identification parameter calculation unit 74 will be described with reference to FIGS.

  FIG. 8 is a flowchart of the process for calculating the identification parameter DFTHF.

  In step S171, the base value DB is calculated by referring to the map based on the current measurement value GTM of the air flow meter. FIG. 9 shows an example of the map. The horizontal axis of the graph represents the measured value GTM of the air flow meter, and the vertical axis represents the corresponding base value DB. Referring to FIG. 9, the base value DB is set larger as the measured value GTM of the air flow meter is larger. Due to the action of the base value DB, the larger the measured value GTM of the air flow meter, the more the value of the identification parameter DFTHF calculated from the identification value DFIL increases in the negative direction, and the throttle correction amount increases.

  In step S173, the intake temperature correction coefficient KDTA is calculated by referring to the map based on the intake air temperature TA. FIG. 10 shows an example of the map. The horizontal axis of the graph represents the intake air temperature TA, and the vertical axis represents the corresponding intake air temperature correction coefficient KDTA. Referring to FIG. 10, the lower the intake air temperature TA, the larger the intake air temperature correction coefficient KDTA is set. By the function of the intake air temperature correction coefficient KDTA, the value of the identification parameter DFTHF increases in the negative direction as the intake air temperature TA is lower, and the correction amount of the throttle increases.

  In step S175, the atmospheric pressure correction coefficient KDPA is calculated by referring to the map based on the atmospheric pressure PA. FIG. 11 is a diagram showing an example of a map. The horizontal axis of the graph represents the atmospheric pressure PA, and the vertical axis represents the corresponding atmospheric pressure correction coefficient KDPA. Referring to FIG. 11, the atmospheric pressure correction coefficient KDPA is set larger as the atmospheric pressure PA is higher. Due to the action of the atmospheric pressure correction coefficient KDPA, the higher the atmospheric pressure PA, the more the value of the identification parameter DFTHF increases in the negative direction, and the throttle correction amount increases.

  In step S177, a correction value DTAPA is calculated. This calculation is performed by equation (5) using the identification value DFIL, the intake air temperature correction coefficient KDTA, and the atmospheric pressure correction coefficient KDPA.

DTAPA = KDTA x KDPA x DFIL (5)
In step S179, the identification parameter DFTHF is calculated. This calculation is performed by the equation (6) using the correction value DTAPA and the base value DB calculated in step S171.

DFTHF = DTAPA − DB (6)
As described above, since the identification value DFIL takes a negative value, DTAPA also takes a negative value. The base value DB takes a larger value as the intake air amount is larger. Therefore, from the equation (6), the identification parameter DFTHF is corrected so as to increase in the negative direction as the intake air amount increases, the intake air temperature TA decreases, or the atmospheric pressure PA increases.

  Next, a process for calculating the clogging coefficient KTHC will be described with reference to FIG. This routine is executed at predetermined time intervals.

  In step S201, the value of the flag F_K is checked. The flag F_K is initialized to zero when the operation cycle (from engine start to stop) is started. Therefore, when this routine is executed for the first time, the process proceeds to step S203, and the current clogging coefficient KTHC is stored as KTHCLAST. That is, the clogging coefficient calculated last in the previous operation cycle is stored as KTHCLAST.

  In step S209, the flag F_K is set to 1 to indicate that the clogging coefficient initial processing has been completed.

  Next, when this routine is entered, since the value of the flag F_K is 1, the process proceeds to step S219, and a process of updating the clogging coefficient KTHC is performed.

  In step S219, the identification parameter DFTHF is smoothed, and the smoothed identification parameter GAMIPC is calculated. This calculation is performed according to the equation (7), for example.

GAMIPC = C × DFTHF + (1−C) × GAMIPC (previous value) (7)
Here, C is a smoothing coefficient, for example, 0.008.

  In step S221, the temporary clogging coefficient kthctmp is calculated by referring to the map based on the smoothing identification parameter GAMIPC. FIG. 13 shows an example of the map. The horizontal axis of the graph represents the smoothing identification parameter GAMIPC, and the vertical axis represents the corresponding provisional clogging coefficient kthctmp. Referring to FIG. 13, the provisional clogging coefficient kthctmp is set larger as the smoothing identification parameter GAMIPC increases in the negative direction.

  In step S223, an update allowable range is set for the clogging coefficient KTHCLAST calculated in the previous operation cycle. Specifically, the upper limit value ktchmax of the allowable range is calculated by adding a predetermined value to the clogging coefficient KTHCLAST calculated in the previous operation cycle, and the allowable value is calculated by subtracting the predetermined value from the clogging coefficient KTHCLAST. Calculate the lower limit value kthcmin of the range.

  In step S224, the temporary clogging coefficient kthctmp is limited within the allowable update range. If the temporary clogging coefficient kthctmp exceeds the upper limit value kthcmax, the clogging coefficient KTHC is set to the upper limit value kthcmax. If the provisional clogging coefficient kthctmp falls below the lower limit value kthcmin, the clogging coefficient KTHC is set to the lower limit value kthcmin. Thus, the update range of the clogging coefficient KTHC is limited.

  With reference to FIG. 14, the process of calculating the target throttle opening degree THICMD will be described. This routine is executed at predetermined time intervals.

  In step S231, the control amount ICMDTH is calculated according to the above-described equation (1). In steps S233 and S235, the upper limit value THICMDC and the lower limit value THICMDX corresponding to the control amount ICMDTH are calculated by referring to the throttle characteristics 83 and 81 in the map shown in FIG. 3 based on the control amount ICMDTH.

  In step S237, as shown in Expression (8), proportional calculation is performed with respect to the upper limit value THICMDC and the lower limit value THICMDX using the clogging coefficient KTHCLAST calculated in the previous operation cycle. Thus, the target throttle opening degree THICMD is calculated.

Target throttle opening THICMD =
KTHCLAST x THICMDC + (1-KTHCLAST) x THICMDX (8)
Here, the reason why the clogging coefficient KTHCLAST calculated in the previous operation cycle is used is that in this operation cycle, the clogging coefficient KTHC is updated at a predetermined time interval, and the value is not yet determined. . In addition, since the clogging of the intake pipe does not change in a short period, an appropriate target throttle opening can be calculated using the clogging coefficient calculated in the previous operation cycle.

  Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to such embodiments.

It is a block diagram which shows the whole structure of the idle speed control apparatus of the internal combustion engine according to one Embodiment of this invention. It is a functional block diagram of the intake air amount control device according to one embodiment of the present invention. 6 is a map showing a throttle opening THICMD to be set with respect to an air amount ICMDTH to be taken into the engine. It is a flowchart of the process which calculates the identification value DFIL of the disturbance component of an intake pipe. It is a flowchart which shows the process which calculates the identification error EDIPC of an intake pipe model. It is a flowchart which shows the process which calculates the update coefficient KPIPC of an identification process. It is a figure which shows an example of the map which calculates gain PDIPC based on error DGTM. It is a flowchart of the process which calculates the identification parameter DFTHF. It is a figure which shows an example of the map which calculates base value DB based on the airflow meter measured value GTM. It is a figure which shows an example of the map which calculates the intake temperature correction coefficient KDTA based on the intake temperature TA. It is a figure which shows an example of the map which calculates atmospheric pressure correction coefficient KDPA based on atmospheric pressure PA. It is a flowchart of the process which calculates clogging coefficient KTHC. It is a figure which shows the map which calculates provisional clogging coefficient kthctmp based on the smoothing identification parameter GAMIPC. It is a flowchart of the process which calculates target throttle opening THICMD.

Explanation of symbols

17 Air flow meter 20 Throttle opening sensor 60 ECU
72 Disturbance Identification Unit 73 Identification Value Correction Unit 74 Identification Parameter Calculation Unit 75 Clogging Coefficient Calculation Unit

Claims (2)

An apparatus for controlling the amount of intake air to an internal combustion engine,
Intake air amount detection means for detecting the intake air amount upstream of the throttle valve provided in the intake pipe of the internal combustion engine ;
The throttle valve opening detecting means for detecting the opening of the throttle valve and the intake pipe of the internal combustion engine are modeled using the detected intake air amount and the opening of the throttle valve , and disturbance components of the model are expressed. An identification means for identifying;
Clogging coefficient calculating means for calculating a clogging coefficient representing the degree of clogging of the intake pipe of the internal combustion engine based on the identified disturbance component, and
An intake air amount control device for an internal combustion engine, wherein the opening degree of the throttle valve is adjusted based on the clogging coefficient. Correction means for correcting the identified disturbance component based on the operating environment of the internal combustion engine;
Means for obtaining an identification parameter representing a deviation between the corrected disturbance component and a reference value;
2. The intake air amount control device for an internal combustion engine according to claim 1, wherein the clogging coefficient calculating means calculates the clogging coefficient based on the identification parameter.

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