JP2009197720A - Control device for vehicle internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To predict a future throttle opening without performing delay control over a throttle and to suppress influence on control over an air-fuel ratio by the accuracy of a predicted result, in a control device for a vehicle internal combustion engine calculating a control parameter value for control over the air-fuel ratio based on the future throttle opening by a predetermined pre-read time in comparison with the present. <P>SOLUTION: A change in the present throttle angle is multiplied by pre-read time to thereby calculate as a predicted variation in the future throttle opening with respect to the present throttle opening. If a rate of change of torque demand made to serve as the base of a target opening is low, the change in the throttle angle is corrected by a correction coefficient en to suppress the predicted variation to a low level. Thereby, the predicted variation is reduced in comparison with the high rate of change of the torque demand. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle internal combustion engine, and more particularly to a control device for a vehicle internal combustion engine equipped with an electronically controlled throttle.

  In a vehicle internal combustion engine equipped with an electronically controlled throttle, a throttle target opening is set based on the accelerator operation amount of the driver, and an opening command value to be output to the throttle is determined according to the set target opening. Yes. At this time, if a delay time is provided from the setting of the target opening to the output timing of the opening command value, the actual throttle opening changes with a delay by a delay time with respect to the target opening. . Hereinafter, control for delaying the output timing of the opening command value is referred to as throttle delay control. By performing the throttle delay control, it becomes possible to predict the future throttle opening from the target opening (opening command value before delay) by the delay time.

The predicted future throttle opening can be reflected in the control parameter value related to the air-fuel ratio control of the internal combustion engine. For example, Japanese Patent Laid-Open No. 2002-201998 discloses a technique for predicting a throttle opening at the closing timing of an intake valve and calculating a fuel injection amount based on an in-cylinder charged air amount obtained from the predicted throttle opening. Has been. If the throttle opening at the closing timing of the intake valve can be accurately predicted, the amount of air charged in the cylinder can be accurately predicted, and the air-fuel ratio control accuracy at the time of transition can be improved. In the technique disclosed in the above publication, an estimated change amount of the throttle opening is calculated by an electronic throttle model based on the opening command value before the delay, and the estimated change amount is added to the current throttle opening, and the intake valve The throttle opening at the closing timing is predicted.
JP 2002-201998 A

  As described above, by performing delay control that provides a delay time for the output timing of the opening command value, it becomes possible to predict the future throttle opening from the target opening. However, on the other hand, a time delay occurs in the torque response of the internal combustion engine in response to the torque request from the driver. Therefore, from the viewpoint of drivability, it is desirable that the delay time is as short as possible. Torque control is also used in vehicle control such as VSC (Vehicle Stability Control system), but it is desirable that the delay time is as short as possible in order to prevent inconvenience in the vehicle control.

  However, in the technique disclosed in the above publication, in order to calculate the fuel injection amount based on an accurate prediction of the in-cylinder charged air amount, at least the time from the fuel injection amount calculation timing to the intake valve closing timing is It is necessary to ensure the delay time. For this reason, if the delay time is simply shortened, the throttle opening at the intake valve closing timing cannot be accurately predicted, and the air-fuel ratio control accuracy at the time of transition is lowered.

  The present invention has been made to solve the above-described problems, and is a vehicle internal combustion engine that obtains a control parameter value related to air-fuel ratio control based on a future throttle opening for a predetermined look-ahead time from the present time. It is an object of the present invention to make it possible to predict a future throttle opening without performing throttle delay control in a control device, and to suppress the influence of the accuracy of the prediction result on air-fuel ratio control.

In order to achieve the above object, the first invention predicts a future throttle opening for a predetermined look-ahead time from the present time, and performs a predetermined control related to the air-fuel ratio control of the internal combustion engine based on the predicted throttle opening. In a control device for an internal combustion engine for a vehicle that calculates a parameter value,
Target opening setting means for setting a target opening of the throttle based on a torque request output from a predetermined torque request generation source;
Throttle control means for operating the throttle to achieve the set target opening;
Index value acquisition means for acquiring an index value indicating the rate of change in the target opening;
Predicting means for predicting a future throttle opening for the pre-reading time from the current time based on the current operating state of the throttle;
In the prediction of the future throttle opening by the predicting means, when the index value is a gradual value, the prediction for reducing the predicted change amount of the future throttle opening with respect to the current throttle opening compared to when the index value is a steep value Correction means;
It is characterized by having.

According to a second invention, in the first invention,
The index value acquisition unit acquires a change speed or a change acceleration of a torque request output from the torque request generation source as the index value.

According to a third invention, in the first invention,
The target opening setting means aggregates torque requests output from a plurality of torque request generation sources and adjusts to one request, and sets the throttle target opening based on the adjusted torque request. ,
The index value acquisition means acquires at least one change speed or change acceleration of torque requests output from the plurality of torque request generation sources as the index value.

According to a fourth invention, in the first invention,
The index value acquisition means acquires, as the index value, a change speed or a change acceleration of a basic signal of a torque request input to the torque request generation source.

According to a fifth invention, in any one of the first to fourth inventions,
The prediction means acquires a current change speed and / or change acceleration of the throttle opening, and based on the acquired change speed and / or change acceleration of the throttle opening, It is characterized by setting a predicted change amount.

According to a sixth invention, in the fifth invention,
The prediction means acquires a change rate and / or change acceleration of the target opening, and a predicted change in the future throttle opening with respect to the current throttle opening as the acquired change rate and / or change acceleration of the target opening is smaller. It is characterized by setting the amount small.

According to a seventh invention, in the fifth or sixth invention,
The prediction correction means increases a predicted change amount of the future throttle opening with respect to the current throttle opening as the difference between the target opening and the current throttle opening is larger when the index value is a steep value. It is characterized by that.

  According to the first invention, it is possible to eliminate the need for throttle delay control by predicting the future throttle opening from the current operating state of the throttle. In addition, when the operating state of the throttle changes greatly after prediction, the air-fuel ratio control based on the predicted throttle opening is affected by this, but this is also dealt with in the first invention. That is, in the first invention, in a situation where it is determined that there is a possibility that the throttle operating state may change significantly within the look-ahead time (that is, a situation where the change in the target opening is moderate), The amount of predicted change in the future throttle opening is reduced. By reducing the predicted change amount from the amount obtained from the current operating state of the throttle, even if the operating state of the throttle changes greatly within the look-ahead time, the predicted throttle opening and the actual throttle opening The influence of the deviation on the air-fuel ratio control can be suppressed. On the contrary, in a situation where the target opening is changing rapidly and it is determined that the current throttle operating state is maintained thereafter, the predicted change amount obtained from the current throttle operating state is used as it is. This makes it possible to perform air-fuel ratio control based on an accurate predicted throttle opening in a transient state where the target opening changes rapidly.

  According to the second aspect of the invention, the change rate or change acceleration of the torque request that is the basis of the target opening is obtained as an index value, so that the change rate or change acceleration of the target opening itself is used as the index value. Thus, the predicted change amount of the throttle opening can be corrected based on newer information for the calculation time required to set the target opening based on the torque request.

  According to the third invention, the change speed or change acceleration of the target opening itself is used as an index by acquiring at least one change speed or change acceleration among a plurality of torque requests as the basis of the target opening as an index value. Compared to the case of setting the value, the throttle opening is predicted based on newer information for the calculation time required to adjust multiple torque requests and set the target opening based on the adjusted torque requests. The amount can be corrected.

  According to the fourth aspect of the invention, the change speed or change acceleration of the basic signal of the torque request input to the torque request generation source is obtained as the index value, so that the change speed or change acceleration of the target opening itself is used as the index value. Compared to the case, the predicted change amount of the throttle opening can be corrected based on newer information for the calculation time required from the output of the torque request to the setting of the target opening.

  According to the fifth invention, the predicted change amount is set based on the current change speed and change acceleration of the throttle opening, so that the current throttle operation state is reliably reflected in the prediction of the future throttle opening. be able to.

  According to the sixth invention, the future throttle opening can be predicted more accurately by taking into account not only the current change speed and change acceleration of the throttle opening but also the change speed and change acceleration of the target opening. Can do.

  According to the seventh aspect, it is possible to predict the future throttle opening more accurately in a transient state where the target opening changes suddenly. If the target opening is changing rapidly and the difference between the target opening and the current throttle opening is large, then the change speed and acceleration of the throttle opening can increase rapidly following the change in the target opening. High nature. In such a case, the deviation between the predicted throttle opening and the actual throttle opening can be suppressed by correcting the predicted change amount to be larger than the value obtained from the current change speed or change acceleration of the throttle opening. it can.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a configuration of a control device for an internal combustion engine for a vehicle as Embodiment 1 of the present invention. The control device of the present embodiment is applied to an internal combustion engine (hereinafter simply referred to as an engine) for a vehicle, and is configured as a control device that controls the operation of a throttle 38 and a fuel injection device 56 that are actuators thereof. Hereinafter, the configuration of the control device of the present embodiment will be described with reference to FIG.

  First, the configuration of a control device for controlling the operation of the throttle 38 will be described. The throttle 38 according to the present embodiment is electronically controlled and is operated by a throttle motor. Control of the operation of the throttle 38 is directly performed by the throttle control unit 36. The throttle control unit 36 receives the target opening of the throttle 38 from the upstream calculation element, and outputs it to the throttle 38 as an opening command value. The throttle 38 operates according to the opening command value. The throttle opening actually realized by the throttle 38 can be measured by a throttle opening sensor 40 attached to the throttle 38.

  The target opening of the throttle 38 is calculated by the target opening calculation unit 34. The target opening calculation unit 34 calculates the target opening based on the target intake air amount of the engine calculated by the upstream target intake air amount calculation unit 32. An inverse model of an air model (intake system model) is used to calculate the target opening. In the air model, the response of the intake air amount to the operation of the throttle 38 is modeled based on fluid dynamics and the like, and is expressed by a mathematical formula. By inputting the intake air amount to the inverse model of the air model, the throttle opening for realizing the intake air amount is calculated. The target opening calculation unit 34 sets the throttle opening converted from the target intake air amount as the target opening of the throttle 38 and outputs it to the throttle control unit 36.

  The target intake air amount calculation unit 32 acquires a target torque of the engine and calculates an intake air amount necessary for realizing the target torque. This calculation uses an air amount map for converting the target torque into the intake air amount. In the air amount map, various operating conditions that affect the relationship between torque and intake air amount, such as ignition timing, engine speed, A / F, and valve timing, are used as parameters. The target intake air amount calculation unit 32 sets the intake air amount converted from the target torque as the target intake air amount of the engine, and outputs it to the target opening calculation unit 34.

  The target torque of the engine is set by the torque adjuster 30. The torque arbitration unit 30 aggregates various torque requests for the engine and mediates it to one value, and outputs the arbitrated torque value as a target torque of the engine. Arbitration here is an operation of obtaining one numerical value from a plurality of numerical values in accordance with a predetermined calculation rule. Calculation rules include, for example, maximum value selection, minimum value selection, averaging, or superposition. The plurality of calculation rules may be appropriately combined.

  The torque request to be arbitrated includes torque required for vehicle control such as VSC (Vehicle Stability Control system) in addition to the torque required by the driver. Of these, the torque required by the driver is calculated by the driver required torque calculator 20, and the torque required by the VSC is calculated by the VSC required torque calculator 22. The driver request torque calculator 20 calculates the driver request torque based on the accelerator pedal operation amount measured by the accelerator sensor 10. The VSC required torque calculation unit 22 calculates the VSC required torque based on the yaw rate of the vehicle measured by the yaw rate sensor 12.

  As described above, the control device according to the present embodiment sets the target opening of the throttle 38 based on torque requests generated from a plurality of torque request generation sources such as drivers and VSCs, and realizes the set target opening. Thus, the operation of the throttle 38 is controlled. The calculation of the target opening is performed at a constant calculation cycle (for example, 8 msec).

  Next, the configuration of a control device for controlling the operation of the fuel injection device 56 will be described. Control of the operation of the fuel injection device 56 is directly performed by the fuel injection control unit 54. The fuel injection control unit 54 receives the fuel injection amount from the upstream calculation element, and calculates the drive time and drive start timing or end timing of the fuel injection device 56 based on the fuel injection amount. Then, the fuel injection device 56 is operated according to the calculated drive time and the drive start timing or end timing. The fuel injection device 56 may be one that injects fuel into the intake port or one that injects fuel directly into the cylinder. Alternatively, a part of the required amount of fuel may be injected into the intake port and the remaining fuel may be directly injected into the cylinder.

  The fuel injection amount by the fuel injection device 56 is calculated by the fuel injection amount calculation unit 52. The fuel injection amount calculation unit 52 performs fuel injection based on the intake air amount of the engine calculated by the upstream intake air amount calculation unit 50 and the target value (target air-fuel ratio) of the in-cylinder air-fuel ratio realized by fuel injection. Calculate the injection amount. When air-fuel ratio feedback control for correcting the fuel injection amount is performed so that the air-fuel ratio of the exhaust gas becomes the target air-fuel ratio, the feedback correction coefficient is also reflected in the calculation of the fuel injection amount. Yes.

  The intake air amount calculation unit 50 calculates the intake air amount of the engine. The intake air amount calculation unit 50 obtains the throttle opening at the closing timing of the intake valve, that is, the determination timing of the intake air amount, and calculates the intake air amount achieved at the throttle opening by the air model. In this air model, it is possible to parameterize and set operating conditions that affect the relationship between the throttle opening and the intake air amount, such as the engine speed, atmospheric pressure, intake air temperature, and air flow rate measured by an air flow meter. It has become.

  The throttle opening used for calculation of the intake air amount is calculated by the pre-reading opening calculation unit 44. In order to accurately calculate the in-cylinder intake air amount, the throttle opening at the closing timing of the intake valve is obtained as information as described above. However, in order to execute fuel injection at an appropriate timing, the calculation of the fuel injection amount must be completed before the intake valve is closed. For this reason, the actual throttle opening at the intake valve closing timing, which is a future value, cannot be acquired at the calculation timing of fuel injection. Therefore, the pre-reading opening degree calculation unit 44 predicts the future throttle opening degree at the present time, that is, the time from the calculation timing of the fuel injection amount to the intake valve closing timing, and the predicted throttle opening degree at the closing timing of the intake valve. Output as throttle opening (hereinafter also referred to as pre-reading opening).

  The prefetch opening calculation unit 44 calculates the prefetch opening based on the current operating state of the throttle 38. More specifically, the look-ahead opening is calculated based on the current throttle opening and the change rate of the throttle opening (change angle per calculation cycle, hereinafter simply referred to as throttle change angle). The current throttle opening is taken from the throttle opening sensor 40 at the same cycle as the target opening calculation cycle. The throttle change angle is taken from the throttle change angle calculation unit 42. The throttle change angle calculation unit 42 calculates the difference between the current throttle opening and the previous throttle opening as the throttle change angle.

The pre-reading opening degree calculation unit 44 calculates the pre-reading opening degree according to the following formula 1. In Equation 1, “prefetch time” is the current time, that is, the time from the fuel injection amount calculation timing to the intake valve closing timing. “En” is a correction coefficient. The value of the correction coefficient en is set by a correction coefficient setting unit 46 described later.
Pre-reading opening = current opening + throttle change angle / en × pre-reading time Formula 1

  As described above, the control device of the present embodiment pre-reads (predicts) the throttle opening at the intake valve closing timing from the current operating state of the throttle 38, and based on the pre-read throttle opening, the predetermined target air-fuel ratio is determined. The operation of the fuel injection device 56 is controlled so as to realize the above. According to such a structure, the delay control of the throttle 38 for air-fuel ratio control is unnecessary, and it is possible to eliminate a decrease in engine responsiveness to a torque request.

  However, when pre-reading the future throttle opening, if the operating state of the throttle 38 changes greatly after pre-reading, specifically, if the throttle change angle changes suddenly, the air-fuel ratio control based on the pre-reading opening is affected. become. With respect to this point, the control device according to the present embodiment deals with this by using the correction coefficient en as a variable and changing the value according to the possibility of a sudden change in the throttle change angle. According to the above equation 1, as the value of the correction coefficient en is larger than 1, the look-ahead of the throttle opening is more negative, and as the value is closer to 1, the look-ahead can be positively performed. Hereinafter, the calculation procedure of the pre-reading opening degree adopted in the present embodiment will be described with reference to FIGS. 2 and 3.

  FIG. 2 is a flowchart showing a look-ahead opening degree calculation routine executed in the present embodiment. In the first step S100 of the routine shown in FIG. 2, the torque change rate determination result is taken into the correction coefficient setting unit 46 from a change rate determination unit 48 described later. When the determination result that the change speed is large is fetched in step S100, the process of step S300 is selected in the next step S200, and the correction coefficient setting unit 46 sets the value of the correction coefficient en to 1. On the other hand, if the determination result that the change rate is small is fetched in step S100, the process in step S310 is selected in the next step S200, and the correction coefficient setting unit 46 sets the value of the correction coefficient en to 2 to 3. Is set to a predetermined value. In the next step S400, the pre-reading opening degree is calculated according to the above equation 1 using the correction coefficient en set in step S300 or S310.

  The change speed determination unit 48 calculates the amount of change per calculation cycle of the target torque output from the torque arbitration unit 30. Then, it is determined whether the torque change speed is large or small based on the magnitude of the torque change amount. If the target torque changes, the target opening set by the target opening setting unit 34 also changes accordingly, and the throttle opening changes following the change of the target opening. Therefore, according to the determination of the torque change speed, it is possible to determine the possibility of a sudden change in the throttle change angle earlier than in the case of determining based on the change speed of the target opening.

  FIG. 3 is a flowchart showing a change speed determination routine executed in the present embodiment. In the first step S101 of the routine shown in FIG. 3, the difference between the current value of the target torque (current torque) and the previous value (previous torque) is calculated as the torque change amount. In the next step S102, the absolute value of the torque change amount is compared with a predetermined threshold value α. If the absolute value of the torque change amount is larger than the threshold value α as a result of the comparison, the change speed determination unit 48 determines that the torque change speed is high (step S103). On the other hand, if the absolute value of the torque change amount is equal to or less than the threshold value α, the change speed determination unit 48 determines that the torque change speed is small (step S104).

  By obtaining the pre-reading opening degree by the procedure as described above, it is possible to set the pre-reading opening degree according to the possibility of a sudden change in the throttle change angle. First, when the torque change speed is small, as shown in FIG. 4, the throttle change angle may change suddenly after the calculation timing of the fuel injection amount (after the current time). Specifically, this is a case where the accelerator pedal is suddenly returned in a slow acceleration state of the vehicle. In such a situation, the throttle change angle also changes from the throttle change angle at the current time. Therefore, when the prefetch opening is calculated based on the current throttle change angle, the prefetch opening is the actual throttle opening (necessary May be greatly deviated from the future opening). In particular, if the pre-reading opening is estimated to be larger than the actual opening, an amount of fuel that is larger than the required amount will be injected, leading to deterioration of fuel consumption and exhaust gas performance.

  Therefore, in the control apparatus of the present embodiment, the value of the correction coefficient en is set to a predetermined value greater than 1 in a situation where it is determined that the torque change speed is small and the throttle change angle may change significantly within the look-ahead time. A value is set (the process in step S310 described above). Then, the pre-reading opening is calculated based on the throttle change angle corrected by the correction coefficient en. As shown in FIG. 4, by calculating the predicted change amount of the look-ahead opening relative to the current throttle opening with the corrected throttle change angle as a reference, the predicted change amount is kept lower than the amount obtained from the current throttle change angle. be able to. According to this, even when the throttle change angle changes greatly within the pre-reading time, it is possible to suppress the influence of the difference between the pre-reading opening and the actual opening on the air-fuel ratio control.

  On the other hand, when the torque change speed is high, it can be determined that the current throttle change angle is maintained for a while after the calculation timing of the fuel injection amount (after the current time), as shown in FIG. Specifically, this is a case where the vehicle is in a state of rapid acceleration or a torque control such as VSC is working according to a driver's request. In such a case, the look-ahead opening can be calculated using the throttle change angle at the fuel injection amount calculation timing (current time) as it is.

  In the control device of the present embodiment, the value of the correction coefficient en is set to 1 in the situation where it is determined that the torque change speed is large and the current throttle change angle is maintained thereafter (the processing in step S300 described above) ). Then, the pre-reading opening is calculated based on the current throttle change angle. According to this, as shown in FIG. 5, the look-ahead opening can be adjusted to the actual throttle opening (required future opening), and the air-fuel ratio control is performed based on the accurately predicted look-ahead opening. Is possible.

  The control device as the first embodiment of the present invention has been described above. The correspondence relationship between the first embodiment and the present invention is as follows.

  In the configuration shown in FIG. 1, the driver request torque calculation unit 20 and the VSC request torque calculation unit 22 correspond to the “torque request generation source” of the first invention, and the torque arbitration unit 30, the target intake air amount setting unit 32, and the target The opening degree setting unit 34 constitutes “target opening degree setting means” of the first invention. The throttle control unit 36 corresponds to the “throttle control means” of the first invention. Further, the pre-reading opening degree calculation unit 44 corresponds to “prediction means” of the first and fifth inventions, and the correction coefficient setting unit 46 corresponds to “prediction correction means” of the first invention. The change speed determination unit 48 corresponds to the “index value acquisition means” of the first and second inventions, and the amount of torque change per calculation cycle of the target torque calculated by the change speed determination unit 48 is the first and second. This corresponds to the “index value” of the second invention. In addition, at least one of the intake air amount calculated by the intake air amount calculation unit 50 and the fuel injection amount calculated by the fuel injection amount calculation unit 52 is the “predetermined control parameter value relating to the air-fuel ratio control” of the first invention. It corresponds to.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS.

  FIG. 6 is a block diagram showing a configuration of a control device for an internal combustion engine for a vehicle as Embodiment 2 of the present invention. The difference between the control device of the present embodiment and the control device of the first embodiment is in the type of information used for determining the torque change speed and the function of the change speed determining unit 60 for using the information. . In the configuration shown in FIG. 6, elements that are the same as those in the first embodiment are given the same reference numerals.

  As shown in FIG. 6, the VSC request torque signal output from the VSC request torque calculation unit 22 is input to the change speed determination unit 60 in addition to the target torque set by the torque arbitration unit 30. The output signal of the VSC required torque calculation unit 22 is normally zero, and the VSC required torque is output when torque control by VSC works. Since the target torque is a total value of the VSC required torque and the driver required torque, when the torque control by the VSC is activated, the subsequent sudden change of the target torque is expected with high accuracy. Therefore, the change speed determination unit 60 obtains a change amount per calculation cycle of the VSC required torque signal, and obtains the change amount as an index value indicating the torque change speed.

  The change rate determination unit 60 also receives the yaw rate measured by the yaw rate sensor 12. Since the VSC required torque is calculated based on the yaw rate, when the yaw rate changes greatly, a subsequent sudden change in the target torque is expected with high accuracy. For this reason, the change rate determination unit 60 obtains a change amount per one calculation cycle of the yaw rate, and acquires the change amount as an index value indicating the torque change rate.

  Further, the accelerator pedal operation amount measured by the accelerator sensor 10 is also input to the change speed determination unit 60. Since the driver required torque is calculated on the basis of the accelerator pedal operation amount, when the accelerator pedal operation amount changes greatly, a subsequent sudden change of the target torque is expected with high accuracy. The change speed determination unit 60 obtains a change amount per operation cycle of the accelerator pedal operation amount, and acquires the change amount as an index value indicating the torque change speed.

  As described above, in the present embodiment, in addition to the change amount of the target torque per calculation cycle, the change amount of the VSC required torque signal per calculation cycle, the change amount of the yaw rate per calculation cycle, and the accelerator pedal A change amount per operation cycle of the operation amount is acquired as an index value indicating a torque change speed. In this way, by using more upstream information as an index value, it is possible to determine the possibility of a sudden change in the throttle change angle more quickly than when only the torque change amount is used as an index value. Become.

  FIG. 7 is a flowchart showing a change speed determination routine executed in the present embodiment. The same step numbers are assigned to processes common to the change speed determination routine executed in the first embodiment. In this routine, if it is determined in step S102 that the absolute value of the torque change amount is equal to or less than the threshold value α, the determinations in steps S105, S106, and S107 are further performed.

  First, in step S105, it is determined whether torque control by VSC has been started based on the amount of change in the VSC required torque signal. In the next step S106, it is determined whether or not the absolute value of the change amount of the accelerator pedal operation amount is larger than the threshold value β. In step S107, it is determined whether or not the absolute value of the change amount of the yaw rate is larger than the threshold value γ. In this routine, when the determination result of any of steps S105, S106, and S107 is Yes, it is determined that the torque change speed is large (step S103). On the other hand, it is determined that the torque change speed is small only when all the determination results in steps S105, S106, and S107 are No (step S104).

  By performing the change speed determination by such a routine, a sudden change in the target torque can be detected in advance, and the value of the correction coefficient en relating to the calculation of the pre-reading opening can be changed to 1 at an early stage. Therefore, according to the control device of the present embodiment, it is possible to improve the prediction accuracy of the look-ahead opening degree in an excessive state such as during rapid acceleration or when the VSC is activated.

  The control apparatus as the second embodiment of the present invention has been described above. The correspondence between the second embodiment and the present invention is as follows.

  In the configuration shown in FIG. 6, the driver request torque calculation unit 20 and the VSC request torque calculation unit 22 correspond to “a plurality of torque request generation sources” of the third invention, and include a torque arbitration unit 30 and a target intake air amount setting unit 32. The target opening setting unit 34 constitutes the “target opening setting means” according to the third aspect of the present invention. The change speed determination unit 60 corresponds to the “index value acquisition means” of the third and fourth inventions, and the change amount of the VSC request torque output from the VSC request torque calculation unit 22 is the “index” of the third invention. Corresponds to “value”. Further, both the change amount of the accelerator pedal operation amount and the change amount of the yaw rate correspond to the “index value” of the fourth invention. The other correspondence relationship between the second embodiment and the present invention is common to the correspondence relationship between the first embodiment and the present invention.

Embodiment 3 FIG.
A third embodiment of the present invention will be described with reference to FIGS.

  FIG. 8 is a block diagram showing a configuration of a control device for an internal combustion engine for a vehicle according to Embodiment 3 of the present invention. The difference between the control device of the present embodiment and the control device of the first embodiment is that the type of information used for calculation of the pre-reading opening and the function of the pre-reading opening calculation unit 64 for using the information. is there. In the configuration shown in FIG. 8, elements that are the same as those in the first embodiment are given the same reference numerals.

  In the present embodiment, in addition to the current throttle opening and throttle change angle, the target opening change speed (change angle per calculation cycle, hereinafter simply referred to as target opening change angle) is calculated as the pre-reading opening. Used for. The target opening change angle is fetched from the target opening change angle calculator 62. The target opening change angle calculation unit 62 calculates the difference between the current target opening and the previous target opening as the target opening change angle.

The pre-reading opening degree calculation unit 64 calculates the pre-reading opening degree according to the following formula 2. The “throttle change estimated angle” used in Equation 2 is calculated by Equation 3 below. “A” and “b” used in Equation 3 are coefficients. The total value of the coefficients a and b is 1, and is adjusted according to the engine operating conditions (for example, engine speed and throttle opening).
Pre-reading opening = current opening + throttle change estimated angle / en × pre-reading time Formula 2
Estimated throttle change angle = a × throttle change angle + b × target opening change angle (Equation 3)

  Thus, by calculating the look-ahead opening not only using the current throttle change angle but also the target opening change angle, the throttle opening at the intake valve closing timing can be predicted more accurately. . For example, as shown in FIG. 9, when the target opening change angle is considerably smaller than the current throttle change angle, it is considered that the throttle change angle gradually decreases after the current time. In this case, when the pre-reading opening is calculated based only on the current throttle change angle, the pre-reading opening may be greatly deviated from the actual throttle opening (necessary future opening). On the other hand, when the pre-reading opening is calculated based on the estimated throttle change angle obtained by Equation 3, the difference between the pre-reading opening and the actual opening is reflected by reflecting the target opening change angle. Can be suppressed.

  The control apparatus as the third embodiment of the present invention has been described above. In the configuration shown in FIG. 8, the pre-reading opening degree calculation unit 64 corresponds to the “prediction means” of the sixth invention. The other correspondence between the third embodiment and the present invention is common to the correspondence between the first embodiment and the present invention.

Embodiment 4 FIG.
A fourth embodiment of the present invention will be described with reference to FIGS.

  FIG. 10 is a block diagram illustrating a configuration of a control device for an internal combustion engine for a vehicle according to a fourth embodiment of the present invention. The control device according to the present embodiment has a configuration obtained by further changing the configuration of the control device according to the third embodiment. The difference between the control device of the present embodiment and the control device of the third embodiment is in the type of information used for calculating the correction coefficient en and the function of the correction coefficient setting unit 68 for using the information. . In the configuration shown in FIG. 10, elements that are the same as those in the third embodiment are given the same reference numerals.

  In the present embodiment, in addition to the torque change speed determination result, the deviation between the target opening and the current throttle opening is used for setting the correction coefficient en. The deviation of the opening is calculated by the deviation calculator 66. FIG. 11 is a flowchart showing a look-ahead opening degree calculation routine executed in the present embodiment. The same step numbers are assigned to the processes common to the pre-reading opening degree calculation routine executed in the first embodiment. In this routine, if it is determined in step S200 that the torque change speed is large, the determination in step S210 is further performed. Then, based on the determination result, the value of the correction coefficient en is set.

  In step S210, the absolute value of the opening degree deviation calculated by the deviation calculation unit 66 is compared with a predetermined threshold value ε. If the absolute value of the opening degree deviation is equal to or smaller than the threshold value ε as a result of the comparison, the process of step S300 is selected, and the correction coefficient setting unit 68 sets the value of the correction coefficient en to 1. On the other hand, when the absolute value of the opening deviation is larger than the threshold value ε, the process of step S320 is selected, and the correction coefficient setting unit 46 sets the value of the correction coefficient en to a predetermined value x smaller than 1. In the next step S400, the pre-reading opening degree is calculated according to the above equation 2 using the correction coefficient en set in step S300, S310 or S320.

  By obtaining the pre-reading opening degree by the procedure as described above, it is possible to further improve the prediction accuracy of the pre-reading opening degree in an excessive state such as during rapid acceleration or during operation of the VSC. For example, as shown in FIG. 12, when the target opening is changing rapidly and there is a large difference between the target opening and the current throttle opening, the subsequent throttle change angle is a change in the target opening. There is a high possibility that the number will increase rapidly. In such a case, in the present embodiment, the value of the correction coefficient en is set to a value smaller than 1 (the process in step S320 described above). The pre-reading opening is calculated based on the throttle change angle corrected by the correction coefficient en. As shown in FIG. 12, by calculating the predicted change amount of the look-ahead opening with respect to the current throttle opening with the corrected throttle change angle as a reference, the predicted change amount is made larger than the amount obtained from the current throttle change angle. As a result, the difference between the pre-reading opening and the actual opening can be suppressed.

  The control device as the fourth embodiment of the present invention has been described above. In the configuration shown in FIG. 10, the correction coefficient setting unit 68 corresponds to the “prediction correction unit” of the seventh invention. The other correspondence relationship between the fourth embodiment and the present invention is common to the correspondence relationship between the third embodiment and the present invention.

Others.
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the following modifications may be made.

  In the first to third embodiments described above, the correction coefficient en may be defined as a continuous function of the torque change speed. However, the value of the correction coefficient en is fixed to 1 when the torque change speed is equal to or greater than a predetermined value, and the value of the correction coefficient en is greater than 1 as the torque change speed is smaller than the predetermined value.

  In the fourth embodiment, when the torque change speed is smaller than a predetermined value, the correction coefficient en is defined as a continuous function of the torque change speed, and when the torque change speed is larger than the predetermined value, the correction coefficient en is set as an opening deviation. It may be defined as a continuous function of absolute values. However, the value of the correction coefficient en is set to a value smaller than 1 as the absolute value of the opening degree deviation is larger.

  In the first to fourth embodiments, the amount of change per one calculation cycle of the target torque, that is, the change speed, is acquired as the “index value indicating the rate of change in the target opening”, but the change acceleration is used as the index value. It can also be used. Further, the change rate of the target opening degree or the change acceleration itself may be used as the index value.

  In the first and second embodiments, the look-ahead opening is calculated from the current throttle change angle. However, the look-ahead opening is calculated in consideration of the throttle change angular velocity, that is, the change acceleration of the current throttle opening. Also good. Similarly, in the third and fourth embodiments, the look-ahead opening may be calculated in consideration of the change acceleration of the current throttle opening and the change acceleration of the target opening.

1 is a block diagram showing a configuration of a control device for an internal combustion engine for a vehicle as Embodiment 1 of the present invention. FIG. It is a flowchart which shows the prefetch opening degree calculation routine performed in Embodiment 1 of this invention. It is a flowchart which shows the change speed determination routine performed in Embodiment 1 of this invention. It is a time chart for demonstrating the look-ahead method of the throttle opening employ | adopted in Embodiment 1 of this invention. It is a time chart for demonstrating the look-ahead method of the throttle opening employ | adopted in Embodiment 1 of this invention. It is a block diagram which shows the structure of the control apparatus of the internal combustion engine for vehicles as Embodiment 2 of this invention. It is a flowchart which shows the change speed determination routine performed in Embodiment 2 of this invention. It is a block diagram which shows the structure of the control apparatus of the internal combustion engine for vehicles as Embodiment 3 of this invention. It is a time chart for demonstrating the look-ahead method of the throttle opening employ | adopted in Embodiment 3 of this invention. It is a block diagram which shows the structure of the control apparatus of the internal combustion engine for vehicles as Embodiment 4 of this invention. It is a flowchart which shows the prefetch opening degree calculation routine performed in Embodiment 4 of this invention. It is a time chart for demonstrating the look-ahead method of the throttle opening employ | adopted in Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Acceleration sensor 12 Yaw rate sensor 20 Driver required torque calculation part 22 VSC required torque calculation part 30 Torque adjustment part 32 Target intake air amount calculation part 34 Target opening degree calculation part 36 Throttle control part 38 Throttle 40 Throttle opening degree sensor 42 Throttle change angle Calculation units 44, 64 Pre-reading opening degree calculation units 46, 68 Correction coefficient setting units 48, 60 Change rate determination unit 50 Intake air amount calculation unit 52 Fuel injection amount calculation unit 54 Fuel injection control unit 56 Fuel injection device 62 Target opening change Angle calculator 66 Deviation calculator

Claims (7)

In a control apparatus for an internal combustion engine for a vehicle that predicts a future throttle opening for a predetermined look-ahead time from the current time and calculates a predetermined control parameter value related to air-fuel ratio control of the internal combustion engine based on the predicted throttle opening,
Target opening setting means for setting a target opening of the throttle based on a torque request output from a predetermined torque request generation source;
Throttle control means for operating the throttle to achieve the set target opening;
Index value acquisition means for acquiring an index value indicating the rate of change in the target opening;
Predicting means for predicting a future throttle opening for the pre-reading time from the current time based on the current operating state of the throttle;
In the prediction of the future throttle opening by the predicting means, when the index value is a gradual value, the prediction for reducing the predicted change amount of the future throttle opening with respect to the current throttle opening compared to when the index value is a steep value Correction means;
A control device for an internal combustion engine for a vehicle.   2. The control apparatus for an internal combustion engine for a vehicle according to claim 1, wherein the index value acquisition means acquires a change speed or a change acceleration of a torque request output from the torque request generation source as the index value. The target opening setting means aggregates torque requests output from a plurality of torque request generation sources and adjusts to one request, and sets the throttle target opening based on the adjusted torque request. ,
2. The vehicle internal combustion engine according to claim 1, wherein the index value acquisition unit acquires at least one change speed or change acceleration of a torque request output from the plurality of torque request generation sources as the index value. Control device.   2. The control of an internal combustion engine for a vehicle according to claim 1, wherein the index value acquisition unit acquires a change speed or a change acceleration of a basic signal of a torque request input to the torque request generation source as the index value. apparatus.   The prediction means acquires a current change speed and / or change acceleration of the throttle opening, and based on the acquired change speed and / or change acceleration of the throttle opening, The control device for an internal combustion engine for a vehicle according to any one of claims 1 to 4, wherein a predicted change amount is set.   The prediction means acquires a change rate and / or change acceleration of the target opening, and a predicted change in the future throttle opening with respect to the current throttle opening as the acquired change rate and / or change acceleration of the target opening is smaller. 6. The control apparatus for an internal combustion engine for a vehicle according to claim 5, wherein the amount is set small.   The predictive correction means increases the predicted change amount of the future throttle opening relative to the current throttle opening as the difference between the target opening and the current throttle opening is larger when the index value is a steep value. The control apparatus for an internal combustion engine for a vehicle according to claim 5 or 6.

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