JP4738463B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine control apparatus, and more particularly to an internal combustion engine control apparatus capable of controlling the opening of a throttle so as to obtain an intake air amount that matches a target intake air amount.

  In recent years, the output shaft torque of an internal combustion engine (hereinafter referred to as an engine), which is a physical quantity that directly affects vehicle control, is used as a required value of driving force from the driver or the vehicle side, and this output shaft torque is output from the engine. A control device for an internal combustion engine has been proposed in which a good running performance of a vehicle can be obtained by determining an air amount, a fuel amount, and an ignition timing, which are engine control amounts, as target values.

  Generally, it is generally known that among the engine control amounts, the intake air amount is the control amount that has the greatest influence on the engine output shaft torque. In order to control the intake air amount with high accuracy, the target effective opening of the engine intake system based on the target intake air flow rate, the atmospheric pressure, the pressure in the intake pipe (hereinafter referred to as “intake manifold pressure”) and the intake air temperature. An area is calculated, and a target throttle opening corresponding to the calculated target effective opening area is output from a correspondence map in which the correspondence between the effective opening area of the intake system and the opening of the throttle is stored in advance. A control device for an internal combustion engine that controls to follow the throttle opening has already been proposed by the applicant of the present application (see Patent Document 1).

  In the case of the control device for an internal combustion engine disclosed in Patent Document 1, the actual throttle opening area and the flow coefficient vary even when the throttle opening is the same due to manufacturing variations of individual throttle bodies. The intake air flow rate may vary from one to another, and variations in the target effective opening area may occur due to variations in sensors that measure intake manifold pressure, atmospheric pressure, or intake air temperature, or due to errors in the estimation method. In some cases, the actual intake air flow rate varies with respect to the target intake air flow rate.

  Therefore, when calculating the throttle opening for obtaining the target intake air flow rate, the applicant of the present application can achieve the target intake air flow rate satisfactorily with respect to variations in the throttle body and various sensors and various estimation errors. In addition, a control apparatus for an internal combustion engine having a throttle opening learning means for learning and correcting the relationship between the effective opening area and the throttle opening has already been proposed.

In a conventional control device for an internal combustion engine, the actual throttle opening changes so as to follow the target throttle opening. Therefore, the basic learning value to be learned at the target throttle opening is set to the throttle opening with the actual effective opening area. The throttle opening learning value is calculated by integrating the throttle opening learning value calculated based on the following formula. .
Actual throttle opening A- (Throttle opening B of actual effective opening area
+ Long time learning value C) of actual effective opening area = Basic learning value D
Basic learning value D x throttle opening learning gain = throttle opening learning value

  FIG. 9 is an explanatory diagram for explaining the contents of control in a conventional control apparatus for an internal combustion engine. FIG. 9A is a slope of a corrected correspondence map (solid line) showing the relationship between the target effective opening area and the throttle opening. Shows a case where the slope is substantially equal to the slope of the relationship between the actual effective opening area and the throttle opening (two-dot chain line), and (b) is a corrected correspondence map showing the relationship between the target effective opening area and the throttle opening. The case where the slope of (solid line) is different from the slope of the relationship between the actual effective opening area and the throttle opening (two-dot chain line) is shown. In FIG. 9, A is the actual throttle opening, B is the throttle opening of the actual effective opening area, C is the long time learning value of the actual effective opening area, D is the basic learning value, and ΔX is the target effective opening area. The deviation of the throttle opening to be learned is shown in FIG.

JP 2007-239650 A

  In the case of a conventional control device for an internal combustion engine, the deviation ΔX of the throttle opening to be learned is equivalent in the target effective opening area, and the slope of the (corresponding solid line) of the corrected correspondence map is (a) and ( If they are different as shown in b), the basic learning value D is different in the cases of (a) and (b). Since the learning of the throttle opening is obtained by sequentially integrating the deviation ΔX multiplied by the throttle opening learning gain, the convergence time of the throttle opening learning depends on this deviation ΔX, and the corrected correspondence map Depending on the slope of (solid line), there are problems such as the occurrence of hunting of the intake air amount and an increase in convergence time.

  The present invention has been made in order to solve the above-described problems in the conventional apparatus. When calculating the throttle opening for obtaining the target intake air amount, variations in the throttle body, various sensors, etc. And correct the relationship between the effective opening area and the throttle opening so that the target intake air volume can be satisfactorily achieved for various estimation errors, and prevent the occurrence of intake air volume hunting and increased convergence time An object of the present invention is to provide a control device for an internal combustion engine.

The control apparatus for an internal combustion engine according to the present invention variably controls the amount of intake air to the internal combustion engine by changing the effective opening area of the intake passage by controlling the throttle opening of a throttle provided in the intake passage of the internal combustion engine. An internal combustion engine control device comprising a throttle opening degree control means for detecting an actual throttle opening degree of the throttle, an intake air amount detection means for detecting an intake air amount to the internal combustion engine, Atmospheric pressure detecting means for detecting atmospheric pressure as atmospheric pressure, intake pipe internal pressure detecting means for detecting the pressure on the internal combustion engine side of the throttle as intake pipe internal pressure, and detecting the intake air temperature on the atmospheric side of the throttle An intake air temperature detecting means; a target intake air amount calculating means for calculating a target intake air amount based on an operating state of the internal combustion engine; and the calculated target intake air amount and the detected amount. Target effective opening area calculating means for calculating a target effective opening area in the throttle opening control means based on at least one of the detected atmospheric pressure, the detected intake pipe internal pressure, and the detected intake air temperature And a target throttle opening that calculates a target throttle opening from the calculated target effective opening area using a correspondence map in which a correspondence relationship between the effective opening area of the intake passage and the throttle opening of the throttle is previously adapted In the throttle opening control means based on at least one of the calculating means, the detected intake air amount, the detected atmospheric pressure, the detected intake pipe internal pressure, and the detected intake air temperature. The actual effective opening area calculating means for calculating the actual effective opening area and the corresponding map are used to calculate the learning throttle opening from the calculated actual effective opening area. Learning throttle opening calculation means, a corrected correspondence map in which the correspondence between the effective opening area and the throttle opening in the correspondence map is corrected based on the calculated throttle opening learning value, and the detection calculates a gain correction opening area by the actual throttle opening degree is, the slope in the slope of the corresponding map and the corrected correspondence map between the gain correction opening area and the actual effective opening area a throttle learning gain calculation means for calculating a throttle learning gain corrected by the gain correction coefficient calculated based on the slope ratio and the calculated actual throttle opening or the target throttle opening calculated and the detected learning and the deviation between the use throttle opening, subjected to integration or filtering by multiplying the throttle learning gain the calculated, Ro Processing means for calculating a torque opening learning value, and the correction opening learning value calculation means for calculating a correction throttle opening learning value based on the calculated throttle opening learning value, correction of the calculated Learning-corrected target opening calculating means for calculating a learning-corrected target throttle opening based on a throttle opening learning value and the calculated target throttle opening, and the throttle opening control means includes the calculation The throttle opening of the throttle is controlled based on the learning corrected target throttle opening .

According to the control apparatus for an internal combustion engine according to the present invention, the gain correction opening is determined by the corrected correspondence map in which the correspondence relationship between the effective opening area and the throttle opening in the correspondence map is corrected, and the detected actual throttle opening. In addition to calculating the area, it is corrected by the gain correction coefficient calculated based on the slope ratio between the slope of the corresponding map and the slope of the corrected corresponding map between the opening area for gain correction and the actual effective opening area. The throttle learning gain calculation means for calculating the throttle learning gain and the difference between the detected actual throttle opening or the calculated target throttle opening and the calculated learning throttle opening are multiplied and integrated by the calculated throttle learning gain. Or processing means for calculating a throttle opening learning value by performing a filtering process, and compensating based on the calculated throttle opening learning value. A corrected opening learning value calculation means for calculating a learning throttle opening learning value, and a target throttle opening after learning correction based on the calculated correcting throttle opening learning value and the calculated target throttle opening The throttle opening control means controls the throttle opening of the throttle based on the calculated learning corrected target throttle opening. Therefore, it is possible to prevent the occurrence of hunting of the intake air amount due to the above and an increase in the convergence time, and to control the throttle opening so that the intake air amount exactly matches the target intake air amount.

Embodiment 1 FIG.
Hereinafter, a control apparatus for an internal combustion engine according to Embodiment 1 of the present invention will be described in detail with reference to the drawings. 1 is a block diagram schematically showing a control device for an internal combustion engine according to Embodiment 1 of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of an engine control unit according to Embodiment 1 of the present invention. is there.

  In FIG. 1, on the upstream side of an intake passage constituting the intake system of the engine 1, an air flow sensor 2 for measuring an intake air flow rate (hereinafter referred to as "intake amount") Qa to the engine 1, an intake air An intake air temperature sensor 3 that directly measures a temperature To (hereinafter referred to as “intake air temperature”) To is provided. The intake air temperature sensor 3 may be configured integrally with the air flow sensor 2 or may be configured separately from the air flow sensor 2. Further, instead of the intake air temperature sensor 3 that directly measures the intake air temperature To, means for estimating the intake air temperature To from other sensor information may be used.

  In the intake system of the engine 1, a throttle 4 is provided on the engine 1 downstream of the air flow sensor 2 for electronically opening and closing to adjust the intake air amount Qa. The throttle 4 is provided with a throttle position sensor 5 for measuring the throttle opening TP. A surge tank 6 that equalizes the pressure in the intake pipe and an intake manifold pressure sensor 7 that directly measures the pressure in the surge tank 6 as the intake manifold pressure Pe are provided on the engine 1 downstream of the throttle 4.

Connected to the surge tank 6 is an EGR valve 8 for opening and closing an EGR (Exhaust Gas Recirculation) pipe communicating with the exhaust pipe of the engine 1. still,
Instead of the intake manifold pressure sensor 7 that directly measures the intake manifold pressure Pe, means for estimating the intake manifold pressure Pe from other sensor information may be used.

  The intake air amount Qa from the air flow sensor 2, the intake air temperature To that is the intake air temperature on the atmosphere side of the throttle 4, the throttle opening TP from the throttle position sensor 5, and the intake manifold pressure from the intake manifold pressure sensor 7 Pe is input to an electronic control unit (hereinafter referred to as “ECU”) 9 as information indicating the operating state of the engine 1 together with detection signals from other sensors (not shown).

The ECU 9 controls the throttle opening TP of the throttle 4 according to the calculation result based on the operating state of the engine 1 to adjust the intake air amount Qa, and the fuel injection device and the ignition device (not shown) of the engine 1 are adjusted. Drive control is performed at a required timing, and the EGR valve 8 is controlled to open and close to improve the combustion state of the engine 1.

  Next, in FIG. 2 showing the configuration of the engine control unit, the ECU 9 includes an input interface (hereinafter referred to as “input I / F”) 9a, an arithmetic processing unit 9b, and an output interface (hereinafter referred to as “output I / F”). / C ") 9c. The input I / F 9a includes an air flow sensor 2, an intake air temperature sensor 3, a throttle position sensor 5, an intake manifold pressure sensor 7, and an atmospheric pressure sensor 10 that directly detects an atmospheric pressure Po that is the pressure on the atmospheric pressure side of the throttle 4. An output terminal is connected, and an intake air amount Qa, intake air temperature To, throttle opening degree Tp, intake manifold pressure Pe, and atmospheric pressure Po detected by each sensor are taken in and input to the arithmetic processing unit 9b. Instead of the atmospheric pressure sensor 10 that directly measures the atmospheric pressure Po, a means for estimating and calculating the atmospheric pressure Po from other sensor information may be used.

  The arithmetic processing unit 9b in the ECU 9 includes a throttle opening control means (to be described later) for controlling the throttle opening TP of the throttle 4, and by controlling the throttle opening TP of the throttle 4 by the throttle opening control means, The intake air amount Qa to the engine 1 is variably controlled by changing the effective opening area of the passage.

  In order to control the throttle opening TP of the throttle 4, the arithmetic processing unit 9 b firstly inputs the aforementioned intake air amount Qa indicating the operating state of the engine 1, the intake air temperature To, the throttle opening Tp, the intake manifold pressure Pe, Based on the atmospheric pressure Po, a target torque of the engine 1 is calculated, and a target intake air amount Qa * for achieving the calculated target torque is calculated.

  Subsequently, the arithmetic processing unit 9b calculates a target effective opening area CAt * for achieving the target intake air amount Qa *, and a target throttle opening degree (hereinafter, “ TP *) (referred to as “target opening”).

  Further, the arithmetic processing unit 9b controls the control command value for the EGR valve 8, the control command value for the throttle valve 4, and the control command value for the injector of the fuel injection device provided in the combustion chamber of the engine 1 and the ignition coil of the ignition device. Is calculated. These calculated control command values drive the EGR valve 8, the throttle 4, the injector (not shown), the ignition coil (not shown) of the ignition device, etc. included in the various actuators 40 via the output I / F 9 c. To each actuator or driving device.

  As a result, the EGR valve, the throttle 4, the injector, the ignition coil, and the like are driven by the respective actuators or driving devices so as to coincide with the respective control command values. As for the throttle 4, as will be described later, the throttle opening is controlled so that the throttle opening TP matches the target opening TP *.

  FIG. 3 is a functional block diagram showing a part of the throttle opening degree control means according to the first embodiment of the present invention provided in the arithmetic processing unit 9b in the ECU 9, in order to achieve the target intake air amount Qa *. The functional block in the case of performing the calculation process of the target opening degree TP * is shown. In FIG. 3, the arithmetic processing unit 9b in the ECU 9 includes a target intake air amount calculating means 90, a target effective opening area calculating means 11, a sound speed calculating means 12, a pressure ratio calculating means 13, and a dimensionless flow rate calculating means. 14 and target opening degree calculation means 15.

The target intake air amount calculation means 90 calculates a target intake air amount Qa * for achieving a target torque corresponding to the operating state of the engine 1 based on the intake air amount Qa from the air flow sensor 2 and sets the target intake air amount Qa * as a target. This is input to the effective opening area calculation means 11. The sound speed calculation means 12 calculates the sound speed ao in the atmosphere based on the intake air temperature To from the intake air temperature sensor 3, and calculates the target effective opening area calculation means 1.
Enter 1

  The pressure ratio calculation means 13 is composed of a divider that calculates the pressure ratio Pe / Po between the intake manifold pressure Pe from the intake manifold pressure sensor 7 and the atmospheric pressure Po from the atmospheric pressure sensor 10, and the calculated pressure ratio Pe / Po is not calculated. Input to the dimensional flow rate calculation means 14. The dimensionless flow rate calculation means 14 calculates a dimensionless flow rate σ based on the pressure ratio Pe / Po from the pressure ratio calculation means 13 and inputs it to the target effective opening area calculation means 11.

The target effective opening area calculating means 11 inputs the target intake air amount Qa * from the target intake air amount calculating means 90, the sound speed a ₀ from the sonic speed calculating means 12, and the dimensionless flow rate σ from the dimensionless flow rate calculating means 14. As information, the target effective opening area CAt * of the throttle 4 is calculated and input to the target opening calculation means 15.

  The target opening calculation means 15 uses a correspondence map (hereinafter, referred to as “CAt-TP map”) in which the correspondence relationship between the effective opening area CAt and the throttle opening TP is adapted in advance. 11 to calculate the target opening TP * corresponding to the target effective opening area CAt *. The calculated value of the target opening TP * is input to the learning basic value calculating means 21 and the learning corrected target throttle opening calculating means 23 described later.

Next, specific calculation of each of the above-described target effective opening area calculating means 11, sound speed calculating means 12, pressure ratio calculating means 13, dimensionless flow rate calculating means 14, and target opening degree calculating means 15 shown in FIG. The processing function will be described. In general, the volumetric flow rate calculation equation of the throttle type flow meter, and the intake amount Qa (volumetric flow rate), the speed of sound a ₀ in the atmosphere, and the flow coefficient C, a opening area of the throttle 4 At the intake manifold pressure Pe, the atmospheric pressure It is represented by the following formula (1) using Po and the specific heat ratio k.

Here, the dimensionless flow rate σ calculated by the dimensionless flow rate calculation means 14 is defined as the following equation (2).

By substituting equation (2) into equation (1), the intake air amount Qa can be expressed as the following equation (3).

The sound velocity a ₀ in the atmosphere is expressed by the following equation (4) when the gas constant R and the intake air temperature To are used.

Further, when the equation (3) is modified, the effective opening area CAt represented by the product of the flow coefficient C and the opening area At of the throttle 4 is calculated as follows: the intake air amount Qa required to achieve the target torque, When the speed of sound a ₀ and the dimensionless flow rate σ are given, they can be calculated by the following equation (5).

Therefore, in equation (5), if the intake air amount Qa is the target intake air amount Qa * and the effective opening area CAt is the target effective opening area CAt *, the target effective opening area calculating means 11 in the ECU 9 is Based on the sound velocity a ₀ and the dimensionless flow rate σ in the atmosphere, the target effective opening area CAt * for achieving the target intake air amount Qa * can be calculated using Equation (5).

  Thus, by calculating the target effective opening area CAt * based on the volumetric flow rate calculation formula of the throttle type flow meter represented by the formula (1), the EGR introduction due to the change of the environmental condition or the opening of the EGR valve 8 Even when the operating state of the engine 1 changes due to the above, it is possible to calculate the target effective opening area CAt * for achieving the target intake air amount Qa * satisfactorily.

By the way, it is not practical to calculate the sound speed a ₀ in the atmosphere necessary for calculating the target effective opening area CAt * using the equation (4) in the ECU 9 because the calculation load becomes enormous. In order to suppress the calculation load of in the ECU 9, the sound speed calculating means 12 is calculated in advance the theoretical values of the speed of sound a ₀ in the atmosphere, is stored as the map data for the intake air temperature To, the target effective opening area before computation processing in the calculating unit 11, and calculates the speed of sound a ₀ in the atmosphere by using the intake air temperature to.

  Similarly, it is not practical to calculate the dimensionless flow rate σ necessary for calculating the target effective opening area CAt * using the equation (2) in the ECU 9 because the calculation load becomes enormous. Therefore, in order to suppress the calculation load in the ECU 9, the dimensionless flow rate calculation means 14 calculates the theoretical value of the dimensionless flow rate σ in advance and stores it as map data for the pressure ratio between the intake manifold pressure Pe and the atmospheric pressure Po. The dimensionless flow rate σ is calculated using the pressure ratio Pe / Po between the intake manifold pressure Pe and the atmospheric pressure Po calculated by the pressure ratio calculation unit 13 before the calculation process by the target effective opening area calculation unit 11. is doing.

  In general, it is known that when the pressure ratio Pe / Po is equal to or less than a predetermined value (about 0.528 in the case of air), the air flow rate passing through the throttle 4 is saturated (so-called choke). When such a choke occurs, it is also known that the dimensionless flow rate σ calculated by the equation (2) becomes a constant value. Therefore, the pressure ratio calculating means 13 includes a pressure ratio fixing means (not shown). When the pressure ratio Pe / Po is equal to or less than the above-mentioned fourth predetermined value, the pressure ratio Pe / Po is set to the fourth ratio. By being fixedly set to a predetermined value, it is configured to be able to cope with the occurrence of choke.

  In the pressure ratio calculation means 13, instead of fixing the pressure ratio Pe / Po to the above-mentioned fourth predetermined value, the dimensionless flow corresponding to the pressure ratio Pe / Po in the dimensionless flow rate calculation means 14 is set. The map value of the flow rate σ may be set to the same value as the map value of the dimensionless flow rate σ corresponding to the fourth predetermined value in the region where the pressure ratio Pe / Po is equal to or smaller than the fourth predetermined value. .

  On the other hand, if the pressure ratio Pe / Po becomes larger than a certain level, the airflow sensor 2 and the intake manifold pressure sensor 7 are affected by the pulsation of the intake air, so that the measured value of the intake air amount Qa is smaller than the actual intake air amount. In addition, the calculation of the dimensionless flow rate σ may be greatly affected by the measurement error of the intake manifold pressure Pe due to the pulsation of the intake air.

  Therefore, a pressure ratio fixing means (not shown) in the pressure ratio calculation means 13 has a pressure ratio Pe / Po of a predetermined value or more at which the air flow sensor 2 and the intake manifold pressure sensor 7 are affected by the pulsation of the intake air. In this case, the pressure ratio Pe / Po is handled as the predetermined value, thereby suppressing the influence of the pulsation of the intake air and ensuring the controllability of the throttle 4.

  In the pressure ratio calculation means 13, instead of fixing the pressure ratio Pe / Po to the above-mentioned third predetermined value, the dimensionless flow rate σ relative to the pressure ratio Pe / Po in the dimensionless flow rate calculation means 14 is set. May be set to the same value as the map value of the dimensionless flow rate σ corresponding to the third predetermined value in the region where the pressure ratio Pe / Po is equal to or greater than the third predetermined value.

  Next, the target opening calculation means 15 calculates the target opening TP * of the throttle 4 using the target effective opening area CAt * calculated by the target effective opening area calculation means 11. At this time, the target opening calculation means 15 uses the measured value of the throttle opening TP from the throttle position sensor 5 and the measured value of the intake air amount Qa from the air flow sensor 2 to calculate the effective opening area CAt calculated by the equation (5). Is stored in advance as a two-dimensional map in which the throttle opening TP and the effective opening area CAt have a one-to-one correspondence. By using this two-dimensional map, the target effective opening area CAt * is obtained. The corresponding target opening TP * is calculated. A two-dimensional map of the throttle opening TP and the effective opening area CAt can be easily created, so that a significant reduction in setting man-hours can be realized.

  FIG. 4 is a functional block diagram schematically showing a calculation processing unit for the target opening after learning correction of the throttle opening control means according to the first embodiment of the present invention. In FIG. 4, the throttle opening degree control means 16 is provided in the arithmetic processing part 9b in ECU9 shown in FIG. As will be described later, the throttle opening control means 16 controls the body of the throttle 4 and various sensors when controlling the throttle 4 so that the target opening TP * calculated by the target opening calculation means 15 is achieved. The throttle opening degree learning value is calculated so that the error between the target intake air amount Qa * and the actual intake air amount Qa due to the variation of 31 and various estimation errors is reduced.

  In FIG. 4, the throttle opening control means 16 includes an actual effective opening area calculation means 17, a learning throttle opening calculation means (hereinafter referred to as "learning opening calculation means") 18, a throttle position sensor. 5, a learning basic value calculating means 19 connected to 5, a throttle learning gain calculating means 20 for calculating a throttle learning gain, a corrected integration processing means 21 for integrating the learning basic value ΔTP, and a throttle opening learning value calculating means. 22, a target opening calculation means 15, and a learning corrected target throttle opening calculation means (hereinafter referred to as “learning corrected target opening calculation means”) 23.

The actual effective opening area calculating means 17 calculates the actual effective opening area CAtr in the throttle opening control means 16 based on the actual intake air amount Qa when the throttle opening of the throttle 4 is controlled to the target opening TP *. calculate. At this time, the actual effective opening area calculating means 17 applies the intake air amount Qa, the atmospheric pressure Po, the intake manifold pressure Pe, and the intake air temperature To to the flow rate calculation formula of the so-called throttle type flow meter, and throttles by the above formula (5). 4 is calculated, and this actual effective opening area CAtr is input to the learning opening calculating means 18.

  The learning throttle opening calculation means 18 calculates from the actual effective opening area CAtr using a correspondence map relationship (hereinafter referred to as “CAt-TP map”) between the throttle opening TP and the effective opening area CAt adapted in advance. The learning throttle opening (hereinafter referred to as “learning opening”) TPi, which is the sum of the learned map throttle opening, the real-time learning value TPR, and the long-time learning value TPLr corresponding to the actual effective opening area CAtr, Calculated and input to the learning basic value calculating means 19.

The learning basic value calculation means 19 calculates a deviation ΔTP (= TP−TPi) between the throttle opening TP detected by the throttle position sensor 5 and the learning opening TPi as a learning basic value, and supplies the corrected integration processing means 21 to the corrected integration processing means 21. input. Here, the throttle opening TP is assumed to be the same as the throttle opening at the timing at which the learning opening TPi is calculated. Note that the target opening TP * may be used instead of the throttle opening TP.

  The throttle learning gain calculating means 20 is an effective opening for gain correction in the corrected CAt-TP map corrected by the long time learning value TPL corresponding to the throttle opening obtained by removing the real time learning value TPR from the actual throttle opening TP. The area CAtg is calculated. The inclination of the effective effective opening area CAtr of the CAt-TP map and the effective correction opening area CAtg section of the CAt-TP map, and the inclination of the effective effective opening area CAtr of the corrected CAt-TP map and the effective opening area CAtg of the gain correction The throttle learning gain Kc is calculated from the slope ratio that is the ratio.

  Next, the above-described method for calculating the slope ratio and the like will be specifically described with reference to FIG. FIG. 5 is an explanatory diagram schematically showing a gain correction coefficient calculation method in the control apparatus for an internal combustion engine according to the first embodiment of the present invention. In FIG. 5, 100 is a CAt-TP map, 200 is a corrected CAt-TP map, and 300 is a relationship between the actual effective opening area CAt and the throttle opening TP.

In the CAt-TP map 100, the throttle opening calculated from the actual effective opening area CAtr is TP_A, the throttle opening calculated from the gain correcting effective opening area CAtg is TP_B, and the corrected CAt-TP map 200 is displayed. In this case, assuming that the throttle opening degree obtained from the actual effective opening area CAtr is TP_C and the throttle opening degree obtained from the gain correction effective opening area CAtg is TP_D, the slope ratio is expressed by the following equation (6).

尚、傾き比を軸としたマップで得られる値をゲイン補正係数としてスロットル学習ゲ
インＫｃを算出してもよい。 Assuming that the slope ratio expressed by the equation (6) is a gain correction coefficient and the set throttle learning gain is K (0 ≦ K ≦ 1), the throttle learning gain Kc is calculated by the following equation (7). .

Note that the throttle learning gain Kc may be calculated using a value obtained from a map with the tilt ratio as an axis as a gain correction coefficient.

  By the way, if the throttle learning gain Kc changes more than necessary, the throttle learning is adversely affected. Therefore, when the calculated throttle learning gain Kc is outside the fourth predetermined range, clip processing is performed so that the calculated throttle learning gain Kc falls within the fourth predetermined range. Thereby, it is possible to prevent the throttle learning gain Kc from changing more than necessary. It should be noted that the same effect can be obtained even when the clip target is a gain correction coefficient.

  Next, the post-correction integration processing means 21 sequentially integrates the value obtained by multiplying the learning basic value ΔTP by the throttle learning gain Kc described above or filters the learning basic value ΔTP to instantaneously calculate the learning basic value ΔTP. The value from which the variation is removed is input to the throttle opening learning value calculation means 22 as the throttle opening learning value TPLRN.

  FIG. 6 is a functional block diagram schematically showing throttle opening learning value calculation means in the throttle opening control means of the control apparatus for an internal combustion engine according to Embodiment 1 of the present invention. In FIG. 6, the throttle opening learning value calculation means 22 uses the throttle opening learning value TPLRN for each learning region corresponding to a real time learning value TPR that is used as feedback control and a point on the CAt axis of the CAt-TP map. The corrected throttle opening learning value (hereinafter referred to as “correction opening learning value”) TPLRNi is generated by performing a process described later, and is distributed to the long time learning value TPL stored in It inputs into the calculation means 23 (illustrated in FIG. 4).

  In addition, since the excessive learning value may be updated when the long-time learning value TPL is updated by changing the throttle learning gain Kc, the throttle opening learning value TPLRN that changes when the long-time learning value TPL is updated. Is limited within a predetermined value range. Accordingly, excessive learning can be prevented, and the throttle opening learning value can be prevented from greatly fluctuating. In the first embodiment of the present invention, the predetermined value of the throttle opening learning value TPLRN that is restricted when the long time learning value TPL is updated is referred to as a fifth predetermined value.

  Thereby, the sum of the throttle opening value on the CAt-TP map 100 and the long time learning value TPL can be brought close to the throttle opening value on the actual CAt-TP map 300. Further, by using the real-time learning value TPR together, an instantaneous error can be absorbed by feedback control.

  Next, the throttle opening learning value calculation means 22 will be described in more detail with reference to FIGS. FIG. 7 is an explanatory diagram schematically showing a long time learning value storing process according to the first embodiment of the present invention. In FIG. 6, the throttle opening learning value calculation means 22 includes a throttle opening comparison means 24, a post-correction integration processing means 21 (shown in FIG. 4), and a long connected to the throttle opening comparison means 24. Time learning value calculation means 25, real time learning value calculation means 26, monotonic increase processing means 28 connected to long time learning value calculation means 25 via switching means 27a, and long connected to monotone increase processing means 28 A correction throttle opening learning value calculating means (hereinafter referred to as “correction”) connected to the time learning value storage means 29 and the real time learning value calculation means 26 via the switching means 27b and connected to the long time learning value storage means 29. (Referred to as “opening learning value calculation means”) 30.

  The throttle opening learning value TPLRN obtained from the post-correction integration processing means 21 is the real-time learning value TPR updated in real time by the throttle opening learning value calculation means 22 and the effective opening area axis of the CAt-TP map. The long-time learning value TPL corresponding to each learning area corresponding to the CAt axis point, which is a point of the current point, is distributed to at least one of them.

6 and 7, first, the throttle opening degree comparison means 24 performs throttle opening degrees TP [m] and TP [m− at points CAt [m] and CAt [m−1] on the CAt axis. Compare the magnitude relationship with 1]. Here, CAt axis points CAt [m] and CAt [m−1
] Is a point on the CAt axis that sandwiches the actual effective opening area CAtr from both sides thereof.

  That is, the value of the throttle opening obtained by adding the long time learning value TPL to the value of the throttle opening TP on the CAt-TP map 100 corresponding to the point CAt [m] having a value larger than the actual effective opening area CAtr of the CAt axis. The long time learning value TPL is added to the value of the throttle opening TP on the CAt-TP map 100 corresponding to the point CAt [m−1] having a value smaller than the actual effective opening area CAtr of the CAt axis. The value of the throttle opening is set to TP [m−1], the magnitude relationship between TP [m] and TP [m−1] is compared, and the real time learning value TPR and the long time learning value that are updated as will be described later. Determine TPL.

  Next, based on the content determined by the throttle opening comparison means 24, the long time learning value calculation means 25 calculates the long time learning value TPL, and the real time learning value calculation means 26 calculates the real time learning value. TPR is calculated. Thereby, excessive learning at the time of learning update can be prevented.

  The switching unit 27a inputs the previous long time learning value TPL (n-1) when a predetermined update prohibition condition described later is satisfied, and prohibits updating of the long time learning value TPL. When the update prohibition condition for the long-time learning value TPL is not established, the long-time learning value TPL calculated by the long-time learning value calculating unit 25 is used in the learning area corresponding to the point on the CAt axis of the CAt-TP map. The final long time learning value TPL is used.

  The switching unit 27b inputs the previous real-time learning value TPR (n-1) as the real-time learning value TPR and prohibits the updating of the real-time learning value TPR when a predetermined update prohibition condition described later is satisfied. When the update prohibition condition for the real-time learning value TPR is not satisfied, the real-time learning value TPR calculated by the real-time learning value calculating unit 26 is set as a final real-time learning value TPR.

  The monotonic increase processing means 28 is the actual CAt-TP relationship after correction by adding the CAt-TP map and the long time learning value TPL, that is, the effective opening area CAt calculated by the throttle opening control means 16 and the throttle. The long time learning value TPL is limited so that the relationship with the opening TP increases monotonously. The long time learning value storage means 29 stores the long time learning value TPL via the monotonous increase processing means 28.

  The correction opening learning value calculation means 30 includes addition means for adding the real time learning value TPR and the long time learning value TPL, and the addition result is obtained as a correction throttle opening learning value (hereinafter referred to as “correction opening learning”). 4) is input to the post-learning corrected target opening degree calculation means 23 shown in FIG. The learning corrected target opening calculation means 23 adds the correction opening learning value TPLRNi and the target opening TP * calculated by the target opening calculation means 15 to obtain a target throttle opening after learning correction (hereinafter, TPLRN * (referred to as “target opening after learning correction”) is calculated.

  Thus, the throttle opening degree control means 16 calculates the throttle opening degree learning value TPLRN based on the learning basic value ΔTP which is the deviation between the throttle opening degree TP and the learning opening degree TPi, and sets the target opening degree TP *. An error between the target intake air amount Qa * and the intake air amount Qa is reduced by controlling the throttle opening TP using the post-learning target opening TPLRN * corrected by the correction opening learning value TPLRNi.

Therefore, when calculating the throttle opening TP for obtaining the target intake air amount Qa *, the target intake air amount Qa * can be satisfactorily achieved with respect to variations in the throttle body and various sensors and errors in various estimation calculations. Thus, the relationship between the effective opening area CAt and the throttle opening TP can be learned and corrected.

  The long time learning value storage means 29 in the throttle opening learning value calculation means 22 in the throttle opening control means 16 functions as a backup memory. That is, when the engine 1 is stopped or when the control device of the internal combustion engine is turned off, the real time learning value TPR is reset and the long time learning value TPL is held in the long time learning value storage means 29.

  FIG. 8 is an explanatory diagram schematically showing the calculation processing of the throttle opening learning value according to the first embodiment of the present invention. Next, with reference to FIGS. 8 and 7, the calculation process for each learning region of the long-time learning value TPL according to the first embodiment of the present invention will be specifically described.

  In FIG. 8, 100 is a CAt-TP map, 110 is a map obtained by adding a long time learning value TPL to the CAt-TP map, and 120 is a map obtained by adding a real time learning value TPR to the CAt-TP map. . As shown in FIG. 8, the difference between the point a and the point b, which is the throttle opening deviation between the throttle opening TP corresponding to the actual effective opening area CAtr of the intake air amount Qa and the learning opening TPi, is learned. The basic value ΔTP. As described above, the post-correction integration processing means 21 sequentially integrates the value obtained by multiplying the learning basic value ΔTP by the throttle learning gain Kc described above, or filters the learning basic value ΔTP, and instantaneously calculates from the learning basic value ΔTP. A value from which the typical variation is removed is calculated as a throttle opening learning value TPLRN.

  In FIG. 7, as described above, the points correspond to the points CAt [m] and CAt [m−1] on the CAt axis of the CAt-TP map 100 sandwiching the throttle opening TP and the actual effective opening area CAtr, respectively. The magnitude relationship between TP [m] and TP [m-1] on the CAt-TP map 100 to be compared is compared by the throttle opening degree comparing means 24, the real time learning value calculating means 26 calculates the real time learning value TPR, The long time learning value TPL is calculated by the long time learning value calculation means 25.

  There are three kinds of magnitude relationships between TP [m] and TP [m-1] described above, and each process is as follows.

ここに、所定値Ａとは、ＣＡｔ軸ポイント上でのリアルタイム学習値ＴＰＲの最大値であり、任意に設定できるものとする。但し、ＴＰ［ｍ］がスロットル開度ＴＰを上回らないこととする。 First, of the comparison results by the throttle opening comparison means 24, as a first magnitude relationship, when the throttle opening TP is equal to or greater than TP [m], that is, the throttle opening TP exists in the A region in FIG. In this case, in the long-time learning value calculation means 25, the long-time learning value TPL is calculated from the previous long-time learning value TPL [m] (n−1) corresponding to CAt [m] by the following equation (8). ), Throttle opening learning value TPLRN, and previous real-time learning value TP
It is calculated by subtracting a predetermined value A from the sum of R (n−1).

Here, the predetermined value A is the maximum value of the real-time learning value TPR on the CAt axis point, and can be arbitrarily set. However, it is assumed that TP [m] does not exceed the throttle opening TP.

At this time, in the real-time learning value calculation means 26, the real-time learning value TPR is calculated from the throttle opening learning value TPLRN, the previous real-time learning value TPR (n-1) and the previous time by the following equation (9). Long time learning value TPLr (n− in actual effective opening area CAtr
It is calculated by subtracting the long time learning value TPLr at the actual effective opening area CAtr from the sum of 1).

Next, as a second magnitude relationship among the comparison results by the throttle opening comparison means 24, when the throttle opening TP is smaller than TP [m] and larger than TP [m-1], that is, B in FIG. When the throttle opening TP exists in the region, the real-time learning value calculation means 26 calculates the throttle opening learning value TPLRN by adding the throttle opening learning value TPLRN to the real-time learning value TPR according to the following equation (10).

ここに、所定値Ｂとは、ＣＡｔ軸ポイント上でのＴＰＲの最小値であり、任意に設定できるものとする。但し、ＴＰ［ｍ−１］がスロットル開度ＴＰを下回らないこととする。 Of the comparison results by the throttle opening comparison means 24, as a third magnitude relationship, when the throttle opening TP is equal to or less than TP [m−1], that is, the throttle opening TP exists in the region C in FIG. In this case, in the long time learning value calculation means 25, the long time learning value TPL is calculated from the previous long time learning value TPL [m-1] corresponding to CAt [m-1] by the following equation (11). It is calculated by subtracting the predetermined value B from the sum of (n−1), the throttle opening learning value TPLRN, and the previous real time learning value TPR (n−1).

Here, the predetermined value B is the minimum value of TPR on the CAt axis point, and can be set arbitrarily. However, it is assumed that TP [m−1] does not fall below the throttle opening TP.

In the real-time learning value calculation means 26, the real-time learning value TPR is calculated from the following equation (12): the throttle opening learning value TPLRN, the previous real-time learning value TPR (n-1), and the previous actual effective opening. It is calculated by subtracting the long time learning value TPLr in the actual effective aperture area CAtr from the sum of the long time learning value TPLr (n−1) in the area CAtr.

  As described above, by performing throttle learning using the throttle learning gain Kc corrected by the gain correction coefficient calculated from the inclination ratio between the inclination of the CAt-TP map 100 and the inclination of the corrected CAt-TP map 200. In addition, it is possible to prevent the occurrence of hunting of the intake air amount caused by the inclination of the CAt-TP map 100 and the inclination of the corrected CAt-TP map 200 and the increase of the convergence time.

  Further, in order to prevent the gain correction coefficient from fluctuating greatly, a throttle correction gain calculation means 20 sets a gain correction coefficient separately under the following conditions.

In other words, in the region where the throttle learning has converged, the slope ratio fluctuates greatly with a slight fluctuation. Therefore, the deviation between the actual effective opening area CAtr and the gain correction effective opening area CAtg is within the first predetermined range, or the deviation between the throttle openings TP_C and TP_D obtained from the corrected CAt-TP map 200 is the second. If it is within the predetermined range, the gain correction coefficient is set to the first predetermined value. Thereby, it is possible to prevent the gain correction coefficient from fluctuating greatly.

  When the slope ratio is within the third predetermined value range, the difference between the slope of the CAt-TP map 100 and the slope of the corrected CAt-TP map 200 is small. There is no need to change frequently, and the gain correction coefficient is set to the second predetermined value. This can prevent the gain correction coefficient from fluctuating.

1 is a configuration diagram schematically showing an internal combustion engine control apparatus according to Embodiment 1 of the present invention; FIG. It is a block diagram which shows schematic structure of the engine control part by Embodiment 1 of this invention. It is a functional block diagram which shows a part of throttle opening control means by Embodiment 1 of this invention. It is a functional block diagram which shows roughly the calculation process part of the target opening after learning correction | amendment of the throttle opening control means by Embodiment 1 of this invention. It is explanatory drawing which shows roughly the gain correction coefficient calculation method by Embodiment 1 of this invention. It is a functional block diagram which shows roughly the calculation process part of the throttle opening learning value of the throttle opening control means by Embodiment 1 of this invention. It is explanatory drawing which shows roughly the storage process of the long time learning value by Embodiment 1 of this invention. It is explanatory drawing which shows roughly the calculation process of the throttle opening learning value by Embodiment 1 of this invention. It is explanatory drawing explaining the control content in the control apparatus of the conventional internal combustion engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Airflow sensor 3 Intake temperature sensor 4 Throttle 5 Throttle position sensor 6 Surge tank 7 In manifold pressure sensor 8 EGR valve 9 ECU 9b Arithmetic processing part 10 Atmospheric pressure sensor 11 Target effective opening area calculation means 12 Sonic speed calculation means 13 Pressure ratio calculation Means 14 Dimensionless flow rate calculation means 15 Target opening degree calculation means 16 Throttle opening degree control means 17 Actual effective opening area calculation means 18 Learning opening degree calculation means 19 Learning basic value calculation means 20 Throttle learning gain calculation means 21 Corrected integration processing Means 22 Throttle opening learning value calculating means 23 Learning corrected target opening calculating means 24 Throttle opening comparing means 25 Long time learning value calculating means 26 Real time learning value calculating means 27a, 27b Switching means 28 Monotonic increase processing means 29 Long time習値 storage unit 30 for correction opening learning value calculation means 31 the various sensors 40 various actuators 90 target intake air amount calculating means

Claims (6)

An internal combustion engine comprising throttle opening control means for controlling the throttle opening of a throttle provided in an intake passage of the internal combustion engine to change the effective opening area of the intake passage to variably control the intake amount to the internal combustion engine An engine control device,
Means for detecting an actual throttle opening of the throttle;
An intake air amount detecting means for detecting an intake air amount to the internal combustion engine;
Atmospheric pressure detection means for detecting the atmospheric pressure of the throttle as atmospheric pressure;
An intake pipe internal pressure detecting means for detecting the pressure on the internal combustion engine side of the throttle as an intake pipe internal pressure;
An intake air temperature detecting means for detecting an intake air temperature on the atmosphere side of the throttle;
Target intake air amount calculating means for calculating a target intake air amount based on the operating state of the internal combustion engine;
Based on at least one of the calculated target intake air amount, the detected atmospheric pressure, the detected intake pipe internal pressure, and the detected intake air temperature, the target effective in the throttle opening control means. Target effective opening area calculating means for calculating the opening area;
Target throttle opening calculation means for calculating a target throttle opening from the calculated target effective opening area using a correspondence map in which a correspondence relationship between the effective opening area of the intake passage and the throttle opening of the throttle is previously adapted. When,
Based on at least one of the detected intake air amount, the detected atmospheric pressure, the detected intake pipe internal pressure, and the detected intake air temperature, an actual effective opening in the throttle opening control means. An actual effective opening area calculating means for calculating an area;
A learning throttle opening calculation means for calculating a learning throttle opening from the calculated actual effective opening area using the correspondence map;
Based on the calculated throttle opening learning value, gain correction is performed based on the corrected correspondence map in which the correspondence between the effective opening area and the throttle opening in the correspondence map is corrected and the detected actual throttle opening. calculates a use opening area, in between the gain correction opening area and the actual effective opening area, is calculated based on the slope ratio of the slope of inclination as the corrected correspondence map of the correspondence map a throttle learning gain calculation means for calculating a throttle learning gain corrected by the gain correction coefficient,
The deviation between the detected actual throttle opening or the calculated target throttle opening and the calculated learning throttle opening is multiplied and integrated by the calculated throttle learning gain.
Is a processing means for performing a filtering process to calculate a throttle opening learning value,
A correction opening learning value calculating means for calculating a correction throttle opening learning value based on the calculated throttle opening learning value;
Learning corrected target opening calculation means for calculating a learning corrected target throttle opening based on the calculated correction throttle opening learning value and the calculated target throttle opening;
With
The control device for an internal combustion engine, wherein the throttle opening control means controls the throttle opening of the throttle based on the calculated learning corrected target throttle opening .   The gain correction coefficient is set to a first predetermined value when a deviation between the actual effective opening area and the gain correction opening area is within a first predetermined range. Control device for internal combustion engine.   When the deviation of the throttle opening calculated from the actual effective opening area and the gain correction opening area using the corrected correspondence map is within a second predetermined range, the gain correction coefficient is 3. The control device for an internal combustion engine according to claim 1, wherein the control device is set to a predetermined value.   The slope of the section between the gain correction opening area and the actual effective opening area in the corrected correspondence map, and the slope of the section between the gain correction opening area and the actual effective opening area in the correspondence map 4. The control device for an internal combustion engine according to claim 1, wherein the gain correction coefficient is set to a second predetermined value when an inclination ratio of the engine is within a third predetermined range. 5.   5. The control device for an internal combustion engine according to claim 1, wherein the throttle learning gain corrected by the gain correction coefficient is limited so as not to be out of a fourth predetermined range. 6. . The control apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the throttle opening degree learning value that changes when the throttle opening degree learning value is updated is limited within a fifth predetermined range.

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