JP6769195B2 - Internal combustion engine control device - Google Patents

Description

The present invention relates to a control device for an internal combustion engine.

A control device for an internal combustion engine is known in which the opening degree of an intake throttle valve provided in an intake passage of an internal combustion engine is feedback-controlled by PID control based on a target intake pressure and an actual intake pressure.

JP-A-2009-57872

By the way, when the operating state of the internal combustion engine is in a transient operating state in which the operating state suddenly changes, the responsiveness of the intake throttle valve may be relatively deteriorated, the actual intake pressure may not catch up with the target intake pressure, and the controllability may be deteriorated. Therefore, for example, an acceleration delay may occur during acceleration.

Therefore, the present invention was conceived in view of such circumstances, and an object of the present invention is to provide a control device for an internal combustion engine capable of improving controllability when the operating state of the internal combustion engine is in a transient operating state.

According to one aspect of the invention
A control device for controlling an internal combustion engine, wherein the internal combustion engine has an intake throttle valve, and the control device has a control unit configured to control the intake throttle valve.
The control unit feedback-controls the opening degree of the intake throttle valve based on the target intake pressure and the actual intake pressure by PID control, and when the operating state of the internal combustion engine is a transient operating state, the D term of the PID control. Is provided, a control device for an internal combustion engine, characterized in that the fuel injection amount is calculated based on the amount of change per unit time.

Preferably, when the operating state of the internal combustion engine is not the transient operating state, the control unit sets the D term of the PID control to the amount of change in the target intake pressure per unit time and the amount of change in the actual intake pressure per unit time. Calculated based on the difference between.

According to another aspect of the invention
A control device for controlling an internal combustion engine, wherein the internal combustion engine has an intake throttle valve, and the control device has a control unit configured to control the intake throttle valve.
The control unit is configured to feedback-control the opening degree of the intake throttle valve by PID control based on the target intake pressure and the actual intake pressure.
The control unit is
The first target of the intake throttle valve including the first D term of PID control calculated based on the difference between the change amount of the target intake pressure per unit time and the change amount of the actual intake pressure per unit time. The opening degree and the second target opening degree of the intake throttle valve including the second D term of PID control calculated based on the amount of change in the fuel injection amount per unit time are calculated.
The first target opening and the second target opening are changed while changing the weighting between the first target opening and the second target opening according to the degree of transient operation of the internal combustion engine. A control device for an internal combustion engine is provided, which is configured to calculate the final target opening degree of the intake throttle valve based on the above.

Preferably, the control unit increases the weighting of the second target opening degree as the degree of transient operation of the internal combustion engine increases.

Preferably, the control unit determines the weighting between the first target opening degree and the second target opening degree based on the amount of change in the fuel injection amount per unit time.

According to the present invention, it is possible to improve the controllability when the operating state of the internal combustion engine is in the transient operating state.

It is the schematic which shows the structure of 1st Embodiment of this invention. It is a flowchart of the control routine in 1st Embodiment. It is a figure which shows each map. It is a flowchart of the control routine in 2nd Embodiment. It is a figure which shows the weight map.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a schematic view showing the configuration of the first embodiment of the present invention. The internal combustion engine (referred to as an engine) 1 is a multi-cylinder engine mounted on a vehicle (not shown). In the present embodiment, the vehicle is a large vehicle such as a truck, and the engine 1 as a vehicle power source mounted on the large vehicle is an in-line 4-cylinder diesel engine. However, the type, type, use, and the like of the vehicle and the internal combustion engine are not particularly limited. For example, the vehicle may be a small vehicle such as a passenger car, and the engine 1 may be a gasoline engine.

The engine 1 includes an engine main body 2, an intake passage 3 and an exhaust passage 4 connected to the engine main body 2, a turbocharger 14, and a fuel injection device 5. The engine body 2 includes structural parts such as a cylinder head, a cylinder block, and a crankcase, and movable parts such as a piston, a crankshaft, and a valve housed therein.

The fuel injection device 5 includes a common rail type fuel injection device, and includes a fuel injection valve, that is, an injector 7, provided in each cylinder, and a common rail 8 connected to the injector 7. The injector 7 injects fuel directly into the cylinder 9, that is, into the combustion chamber. The common rail 8 stores the fuel injected from the injector 7 in a high pressure state.

The intake passage 3 is mainly defined by an intake manifold 10 connected to the engine body 2 (particularly a cylinder head) and an intake pipe 11 connected to the upstream end of the intake manifold 10. The intake manifold 10 distributes and supplies the intake air sent from the intake pipe 11 to the intake ports of each cylinder. The intake pipe 11 is provided with an air cleaner 12, an air flow meter 13, a compressor 14C of a turbocharger 14, an intercooler 15, and an electronically controlled intake throttle valve 16 in this order from the upstream side. The air flow meter 13 is a sensor for detecting the intake air amount per unit time of the engine 1, that is, the intake flow rate.

The exhaust passage 4 is mainly defined by an exhaust manifold 20 connected to the engine body 2 (particularly a cylinder head) and an exhaust pipe 21 connected to the downstream side of the exhaust manifold 20. The exhaust manifold 20 collects the exhaust gas sent from the exhaust port of each cylinder. A turbine 14T of a turbocharger 14 is provided between the exhaust pipe 21 or the exhaust manifold 20 and the exhaust pipe 21. The exhaust pipe 21 on the downstream side of the turbine 14T is provided with an oxidation catalyst 22, a particulate filter (DPF) 23, a selective reduction NOx catalyst (SCR) 24, and an ammonia oxidation catalyst 26 in this order from the upstream side. An addition valve 25 for adding urea water as a reducing agent is provided in the exhaust passage 4 on the upstream side of the NOx catalyst 24.

The turbocharger 14 includes a variable displacement turbocharger. A nozzle opening degree variable mechanism 28 for changing the nozzle opening degree at the turbine inlet is provided, and the nozzle opening degree variable mechanism 28 is operated by the nozzle actuator 29. The nozzle opening degree variable mechanism 28 has a plurality of movable nozzle vanes that open and close the nozzle, and the nozzle opening degree is increased or decreased by opening and closing the movable nozzle vanes at the same time.

The engine 1 also includes an EGR device 30. The EGR device 30 includes an EGR passage 31 for recirculating a part (referred to as EGR gas) of exhaust gas in the exhaust passage 4 (particularly in the exhaust manifold 20) into the intake passage 3 (particularly in the intake manifold 10), and an EGR. An EGR cooler 32 for cooling the EGR gas flowing through the passage 31 and an EGR valve 33 for adjusting the flow rate of the EGR gas are provided.

A control device for controlling the engine 1 is mounted on the vehicle. The control device includes an electronic control unit (referred to as an ECU) 100 that forms a control unit or a controller. The ECU 100 includes a CPU, a ROM, a RAM, an input / output port, a storage device, and the like. The ECU 100 is configured and programmed to control an injector 7, an intake throttle valve 16, an addition valve 25, an EGR valve 33, and a nozzle actuator 29.

The control device also has the following sensors. Regarding these sensors, in addition to the above-mentioned air flow meter 13, a rotation speed sensor 40 for detecting the rotation speed of the engine, that is, a rotation speed (rpm) per unit time, and an accelerator opening sensor for detecting the accelerator opening. 41 is provided. Further, exhaust temperature sensors 42, 43, 44, 46 for detecting the exhaust temperature (inlet gas temperature) on the upstream side or near the inlet of each of the oxidation catalyst 22, DPF23, NOx catalyst 24, and ammonia oxidation catalyst 26 are provided. ing. Further, a differential pressure sensor 45 for detecting the differential pressure of the exhaust pressures on the upstream side and the downstream side of the DPF 23 is provided. The output signals of these sensors are sent to the ECU 100.

Further, an intake pressure sensor 47 for detecting the intake pressure and a pressure sensor 48 for detecting the turbine inlet pressure are provided. The output signals of these sensors are also sent to the ECU 100. Here, since the engine of the present embodiment is a supercharging type, for convenience, "intake pressure" is rephrased as "supercharging pressure", and "intake pressure sensor 47" is rephrased as "supercharging pressure sensor 47". ..

In the present embodiment, the boost pressure sensor 47 is installed in the intake pipe 11 on the downstream side of the intake throttle valve 16 and immediately before the intake manifold 10. However, the installation position is arbitrary as long as it is on the downstream side of the intake throttle valve 16, and may be installed in, for example, the intake manifold 10. In the present embodiment, the pressure sensor 48 is installed in the EGR passage 31 on the upstream side of the EGR valve 33 and the EGR cooler 32 in the EGR gas flow direction, but the installation position may be on the upstream side of the turbine 14T (particularly the nozzle). This is optional, and may be installed in, for example, the exhaust manifold 20.

Next, the control of the present embodiment, particularly the control of the intake throttle valve 16, will be described. As basic control, the ECU 100 feedback-controls the opening degree of the intake throttle valve 16 by PID control based on the target boost pressure and the actual boost pressure. Further, when the operating state of the engine 1 is not the transient operating state, the ECU 100 sets the D term, that is, the differential term of the PID control as the amount of change in the target boost pressure per unit time and the amount of change in the actual boost pressure per unit time. It is configured to calculate based on the difference between.

On the other hand, the ECU 100 is configured to calculate the D term of the PID control based on the amount of change in the fuel injection amount per unit time when the operating state of the engine 1 is the transient operating state. As a result, the responsiveness of the intake throttle valve 16 when the operating state of the engine 1 is the transient operating state is improved, and the followability of the actual intake pressure to the target intake pressure is improved. Then, the acceleration delay at the time of acceleration is suppressed to improve the controllability.

In the present embodiment, a control mode for quickly raising the temperature of each aftertreatment device such as the oxidation catalyst 22, DPF23, SCR24 and the ammonia oxidation catalyst 26 from the cold start of the engine 1 to the completion of warm-up. That is, the temperature rising mode is executed by the ECU 100. Although details will be described later, it is preferable that the intake throttle valve control of the present embodiment is performed during the execution of the temperature rising mode.

The control routine in this embodiment will be described with reference to FIG. The illustrated routine is repeatedly executed by the ECU 100 every predetermined calculation cycle τ (for example, 10 msec).

In step S101, the ECU 100 has the engine speed Ne detected by the rotation speed sensor 40, the accelerator opening Ac detected by the accelerator opening sensor 41, and the supercharging pressure detected by the supercharging pressure sensor 47, that is, the actual one. Obtain the boost pressure Pr.

In step S102, the ECU 100 determines the fuel injection amount, particularly the target as the indicated injection amount to the injector 7, according to the target fuel injection amount map as shown in FIG. 3A based on the engine speed Ne and the accelerator opening degree Ac. The fuel injection amount Q is calculated. The target fuel injection amount map is created in advance through tests and the like and stored in the ECU 100. This point is the same for the map described later.

In step S103, the ECU 100 sets a target boost pressure Pt, which is a target value of the boost pressure, according to a target boost pressure map as shown in FIG. 3B based on the engine speed Ne and the target fuel injection amount Q. calculate.

In step S104, the ECU 100 calculates the basic opening Vb of the intake throttle valve 16 based on the engine speed Ne and the target fuel injection amount Q according to the basic opening map as shown in FIG. 3C. This basic opening degree Vb forms a feedforward (F / F) term that is uniquely determined according to the engine operating state.

In step S105, the ECU 100 calculates the difference between the target supercharging pressure Pt and the actual supercharging pressure Pr, that is, the supercharging pressure difference ΔP from the equation: ΔP = Pt-Pr.

In step S106, the ECU 100 calculates the P term, that is, the proportional term Vp, and the I term, that is, the integral term Vi in PID control as follows. Both the P term Vp and the I term Vi form a feedback (F / B) term determined based on the supercharging pressure difference ΔP so that the supercharging pressure difference ΔP is zero.

First, regarding the P term Vp, the ECU 100 calculates the P term Vp by multiplying the supercharging pressure difference ΔP by a predetermined proportional gain Kp. Alternatively, the ECU 100 may directly calculate the P term Vp corresponding to the supercharging pressure difference ΔP according to the P term map as shown in FIG. 3 (D). The gradient of the diagram in the P term map represents the proportional gain Kp.

Further, regarding the term I Vi, the ECU 100 calculates the term I Vi by multiplying the integrated value ΣΔP of the supercharging pressure difference from the predetermined time point in the past to the current calculation time by the predetermined integrated gain Ki. Alternatively, the ECU 100 may directly calculate the I-term Vi corresponding to the integrated value ΣΔP of the supercharging pressure difference according to the I-term map as shown in FIG. 3 (D). The gradient of the diagram in the I-term map represents the integral gain Ki. Here, for simplification, the P-term map and the I-term map are shown together in FIG. 3 (D). However, it should be noted that these maps are actually provided separately, and the values of the proportional gain Kp and the integrated gain Ki may be the same or different.

Next, in step S107, the ECU 100 calculates the amount of change in the target fuel injection amount Q per unit time. In this embodiment, the unit time is equal to the calculation period τ. The amount of change per unit time of the target fuel injection amount Q, the difference between the target fuel injection amount Q _n in the present calculation period n, 1 and the target fuel injection amount Q _n-1 in the calculation cycle before the previous n-1 _{(Q n -Q n-1)} , i.e. equal to the target fuel injection amount differential value _{Q '(= Q' n =} Q n -Q n-1). However, the unit time does not have to be equal to the calculation cycle τ, for example, it may be equal to a plurality of times the calculation cycle τ.

Next, in step S108, the ECU 100 determines whether or not the absolute value of the target fuel injection amount differential value Q'is equal to or less than the predetermined transient determination threshold value α (> 0). When the absolute value of the target fuel injection amount differential value Q'is equal to or less than the transient determination threshold value α (| Q'| ≦ α), the ECU 100 considers that the operating state of the engine 1 is not the transient operating state, and proceeds to step S109. .. On the other hand, when the absolute value of the target fuel injection amount differential value Q'is larger than the transient determination threshold value α (| Q'|> α), the ECU 100 considers that the operating state of the engine 1 is the transient operating state, and steps S112. Proceed to. The transient operating state refers to a state in which the operating state of the engine 1 suddenly changes as the engine or vehicle accelerates or decelerates. More specifically, the transient operation state means a state in which the accelerator opening Ac changes suddenly due to the accelerator pedal operation by the driver.

When the absolute value of the target fuel injection amount differential value Q'is larger than the transient judgment threshold α (| Q'|> α), the target fuel injection amount differential value Q'is larger than the positive transient judgment threshold + α (Q). Both'> + α) and the case where the target fuel injection amount differential value Q'is smaller than the negative transient determination threshold −α (Q'<−α) are included. In the former case, the ECU 100 considers the operating state of the engine 1 to be a transient operating state due to acceleration, and in the latter case, the operating state of the engine 1 is regarded as a transient operating state due to deceleration. As described above, in the present embodiment, the magnitudes of the threshold values for the acceleration determination and the deceleration determination are equalized, but these may be different.

When the process proceeds to step S109, the ECU 100 calculates the D term, that is, the differential term VdA in the PID control when it is not in the transient operation state (referred to as the non-transient state) as follows. This differential term VdA is a feedback (determined based on the difference) so that the difference between the amount of change in the target boost pressure Pt per unit time and the amount of change in the actual boost pressure Pr per unit time is zero. It forms the F / B) term.

Again, the unit time is equal to the operation period τ. However, the point that the unit time does not have to be equal to the calculation cycle τ is the same as described above. ECU100 is the amount of change per unit time of the target supercharging pressure Pt, and the target supercharging pressure Pt _n at the current calculation time n, 1 and the target supercharging pressure Pt _n-1 in the calculation cycle before the previous n-1 difference _{(Pt n -Pt n-1)} , i.e. calculated as a value equal to the target boost pressure derivative value _{Pt '(= Pt' n =} Pt n -Pt n-1).

Similarly, ECU 100, the actual boost pressure variation per unit time of Pr, and the actual supercharging pressure Pr _n at the current calculation time n, 1 actual supercharging pressure Pr _n in the calculation period before the last n-1 the difference between the _{-1 (Pr n -Pr n-1} ), i.e. calculated as equal to the actual boost pressure derivative value _{Pr '(= Pr' n =} Pr n -Pr n-1).

Next, the ECU 100 calculates the difference between the target boost pressure differential value Pt'and the actual boost pressure differential value Pr', that is, the boost pressure differential value difference ΔP'from the equation: ΔP'= Pt'-Pr'. Then, the ECU 100 calculates the non-transient D-term VdA by multiplying the boost pressure differential value difference ΔP'by a predetermined non-transient differential gain KdA.

Alternatively, the ECU 100 may directly calculate the non-transient D-term VdA corresponding to the boost pressure differential value difference ΔP'according to the non-transient D-term map as shown in FIG. 3 (E). The gradient of the diagram in the non-transient D-term map represents the non-transient differential gain KdA. Here, for the sake of simplification, the diagram in the non-transient D-term map is substantially the same as the diagram in the P-term map shown in FIG. 3 (D), but it may be different as a matter of course.

Next, in step S110, the ECU 100 uses the following equation (1) to determine the intake throttle valve 16 based on the basic opening degree Vb, P term Vp, I term Vi, and non-transient D term VdA calculated as described above. The final target opening Vt is calculated.
Vt = Vb + Vp + Vi + VdA ... (1)

Next, in step S111, the ECU 100 controls the intake throttle valve 16 according to the target opening degree Vt. That is, the ECU 100 controls the opening degree of the intake throttle valve 16 so that the actual opening degree of the intake throttle valve 16 becomes equal to the target opening degree Vt. This is the end of this routine.

On the other hand, when the process proceeds from step S108 to step S112, the ECU 100 calculates the D term, that is, the differential term VdB in the PID control in the transient operation state (referred to as the transient operation) as follows. This differential term VdB is a feedback (F / B) term determined based on the amount of change in the target fuel injection amount Q per unit time.

Again, the unit time is equal to the operation period τ. However, the point that the unit time does not have to be equal to the calculation cycle τ is the same as described above. ECU100 calculates the amount of change per unit time of the target fuel injection amount Q, as a value equal to the target fuel injection amount differential value Q calculated _{'(= Q' n = Q} n -Q n-1) at step S107 ..

That is, the ECU 100 acquires the value of the target fuel injection amount differential value Q'calculated in step S107, and multiplies the target fuel injection amount differential value Q'by a predetermined transient differential gain KdB to obtain the transient D term VdB. calculate.

Alternatively, the ECU 100 may directly calculate the transient D-term VdB corresponding to the target fuel injection amount differential value Q'according to the transient D-term map as shown in FIG. 3 (F). The gradient of the diagram in the transient D-term map represents the transient differential gain KdB. Here, for the sake of simplicity, the gradient of the diagram in the transient D-term map is substantially the same as the gradient of the non-transient D-term map shown in FIG. 3 (E), but it is naturally different. You may.

Here, as shown in FIG. 3 (F), the upper limit guard value VdB1 and the lower limit guard value VdB2 of the D term VdB at the time of transition are set, and when the target fuel injection amount differential value Q'is a positive predetermined value G1 or more, the transition occurs. The D term VdB is held at the upper limit guard value VdB1, and when the target fuel injection amount differential value Q'is a negative predetermined value G2 or less, the transient D term VdB is held at the lower limit guard value VdB2.

As can be understood from the above description, the target fuel injection amount Q is a value that is immediately determined according to the accelerator opening degree Ac. For example, when the accelerator pedal is suddenly depressed greatly during acceleration and the amount of change in the accelerator opening Ac per unit time is too large, an excessive positive target fuel injection amount differential value Q'is obtained, and an excessive positive transient is obtained. Time D term VdB may be obtained. Then, the opening degree of the intake throttle valve 16 may increase excessively, and the controllability may be deteriorated. The same applies when decelerating. An upper limit guard value VdB1 and a lower limit guard value VdB2 are provided for the purpose of suppressing such an excessive sudden change in the intake throttle valve opening degree. As a result, it is possible to suppress deterioration of controllability due to an excessive change in the accelerator opening degree Ac.

Since the change in boost pressure is gentler than the accelerator opening, no guard value is provided for P term Vp, I term Vi, and non-transient D term VdA. However, it is of course possible to set a guard value.

Next, in step S113, the ECU 100 finally determines the intake throttle valve 16 according to the following equation (2) based on the basic opening degree Vb, P term Vp, I term Vi, and transient D term VdB calculated as described above. Target opening Vt is calculated.
Vt = Vb + Vp + Vi + VdB ... (2)

Next, the ECU 100 proceeds to step S111 and controls the opening degree of the intake throttle valve 16 so that the actual opening degree of the intake throttle valve 16 becomes equal to the target opening degree Vt, as described above. This is the end of this routine.

As described above, according to the present embodiment, when the operating state of the engine 1 is the transient operating state, the transient D-term VdB is calculated based on the target fuel injection amount differential value Q', and the transient D-term is calculated. The target opening Vt of the intake throttle valve 16 is calculated based on VdB. Therefore, the opening degree of the intake throttle valve 16 can be PID controlled based on the target fuel injection amount that changes faster than the boost pressure, and the responsiveness of the intake throttle valve 16 during transient operation can be improved. .. Then, the responsiveness of the actual intake pressure Pr to the target intake pressure Pt can be improved, and the controllability can be improved. At the time of acceleration, the opening delay of the intake throttle valve 16 can be suppressed to suppress the acceleration delay, and at the time of deceleration, the closing delay of the intake throttle valve 16 can be suppressed to suppress the deceleration delay.

Conventionally, even when the operating state of the engine is in the transient operating state, the target opening degree of the intake throttle valve is calculated in the same manner as when the engine is not in the transient operating state, which causes the above-mentioned problem. In the present embodiment, when the operating state of the engine 1 is the transient operating state, the target opening Vt of the intake throttle valve 16 is calculated by using the transient D-term VdB based on the target fuel injection amount differential value Q'. , The above-mentioned problem is solved.

By the way, as described above, the intake throttle valve control of the present embodiment is preferably performed during the execution of the temperature rising mode. That is, during the temperature rise mode execution, the opening degree of the intake throttle valve 16 is reduced as compared with the case where the temperature rise mode is not executed, and the inflow of fresh air is suppressed to perform post-treatments such as the oxidation catalyst 22, DPF23, SCR24 and the ammonia oxidation catalyst 26. The temperature rise of the device is promoted. However, if the accelerator opening degree Ac is rapidly increased at this time and an acceleration request is generated, the opening degree increase of the intake throttle valve 16 is delayed as compared with the time when the temperature rising mode is not being executed, and the acceleration delay tends to occur easily. On the other hand, by executing the intake throttle valve control of the present embodiment during the execution of the temperature rise mode, the opening delay of the intake throttle valve 16 can be suppressed and the acceleration delay can be suppressed even during the execution of the temperature rise mode.

The temperature rising mode is executed by the ECU 100 from the cold start of the engine 1 to the completion of warming up. More specifically, it is executed when the detected value of the water temperature sensor (not shown) is less than a predetermined warm-up completion temperature. The temperature of each aftertreatment device is estimated based on the detected values of the exhaust temperature sensors 42, 43, 44, 46, and the temperature of at least one of them (for example, the oxidation catalyst 22 on the most upstream side) is the predetermined warm-up completion. The temperature rise mode may be executed when the temperature is lower than the temperature. In addition to this, various methods for executing the temperature rising mode, execution conditions, and the like can be considered.

[Second Embodiment]
Next, the second embodiment of the present invention will be described. The same parts as those in the first embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted. Hereinafter, the differences from the first embodiment will be mainly described. The configuration of this embodiment is the same as that shown in FIG. 1, and the content of control of this embodiment is different from that of the first embodiment.

The control routine in this embodiment will be described with reference to FIG.

Steps S201 to S207 are the same as steps S101 to S107 shown in FIG. In step S208, the ECU 100 calculates the non-transient D-term VdA as in step S109.

Then, in step S209, the ECU 100 calculates the target opening degree of the intake throttle valve 16, that is, the target opening degree VtA at the time of non-transientation, by the following equation (1)', as in step S110.
VtA = Vb + Vp + Vi + VdA ... (1)'

Next, in step S210, the ECU 100 calculates the transient D-term VdB as in step S112. Then, as in step S113, the ECU 100 calculates the target opening degree of the intake throttle valve 16, that is, the transient target opening degree VtB in the case of assuming a transient time, by the following equation (2)'.
VtB = Vb + Vp + Vi + VdB ・ ・ ・ (2)'

Next, in step S212, the ECU 100 calculates the weight W corresponding to the target fuel injection amount differential value Q'according to the weight map as shown in FIG. As will be understood later, the weight W determines the weights for each of the non-transient target opening VtA and the transient target opening VtB when calculating the final target opening Vt of the intake throttle valve 16. Is the value of.

As shown in FIG. 5, the weight W is a value within the range of 0 ≦ W ≦ 1. The weight W is zero when the target fuel injection amount differential value Q'is zero, increases as the target fuel injection amount differential value Q'increases from zero, and the target fuel injection amount differential value Q'is a positive predetermined value. When G3 or higher, it is held at 1. Further, the weight W increases as the target fuel injection amount differential value Q'decreases from zero, and is held at 1 when the target fuel injection amount differential value Q'is a negative predetermined value G4 or less.

Next, in step S213, the ECU 100 finally determines the intake throttle valve 16 according to the following equation (3) based on the non-transient target opening VtA, the transient target opening VtB, and the weight W calculated as described above. The target opening Vt is calculated.
Vt = (1-W) ・ VtA + W ・ VtB ・ ・ ・ (3)

Next, in step S214, the ECU 100 controls the opening degree of the intake throttle valve 16 so that the actual opening degree of the intake throttle valve 16 becomes equal to the target opening degree Vt, as in step S111. This is the end of this routine.

According to this control, both the non-transient target opening VtA and the transient target opening VtB are calculated regardless of whether the operating state of the engine 1 is the transient operating state. Then, the weighting of the two is determined according to the degree of the transient operating state, that is, the degree of acceleration or deceleration, and the two are weighted and averaged to calculate the final target opening Vt of the intake throttle valve 16.

For example, the larger the acceleration ratio and the larger the target fuel injection amount differential value Q'on the positive side, the larger the weight W is calculated, and the larger the weight of the target opening VtB at the time of transition. Therefore, the transient D-term VdB based on the target fuel injection amount differential value Q'can be made more effective, and as a result, the opening delay and acceleration delay of the intake throttle valve 16 can be suppressed.

On the contrary, even when the degree of deceleration is large and the target fuel injection amount differential value Q'is large on the negative side, a larger weight W is calculated and the weight of the target opening VtB at the time of transition becomes large. Therefore, the transient D-term VdB based on the target fuel injection amount differential value Q'can be made more effective, and as a result, the closing delay and deceleration delay of the intake throttle valve 16 can be suppressed.

On the other hand, when the operating state of the engine 1 is not the transient operating state, the absolute value of the target fuel injection amount differential value Q'is small, and only a small weight W is calculated. Therefore, this time, the weighting of the target opening VtA in the non-transient state becomes large, the effect of the D-term VdB in the transient state can be suppressed, and the control of the boost pressure main body adapted in the non-transient state can be executed.

As can be understood from FIG. 5, the weight W also reflects an idea similar to the above-mentioned guard value, and the target fuel injection amount differential value Q'is a positive predetermined value G3 or more or a negative predetermined value G4 or less. In the case of, the weight W is held at 1. As a result, the weight W does not increase endlessly in response to an excessive change in the accelerator opening degree that may cause such a case, and the target opening degree Vt is calculated substantially only by the target opening degree VtB at the time of transition, and the accelerator is used. Deterioration of controllability due to excessive change in opening can be suppressed. The absolute values of the predetermined values G3 and G4 may be equal or different.

As described above, this embodiment can also exert the same effects as those of the first embodiment.

In the present embodiment, the non-transitional D term VdA corresponds to the first D term in the claims. Similarly, the transient target opening VdB corresponds to the second D term, the non-transient target opening VtA corresponds to the first target opening, and the transient target opening VtB corresponds to the second target opening. .. The weight W is changed according to the degree of transient operation of the engine 1, and the weights of the non-transient target opening VtA and the transient target opening VtB are changed. In both acceleration and deceleration, the higher the degree of transient operation of the engine 1, the larger the weight W, and the larger the weight of the target opening VtB during transient operation. The weighting between the non-transient target opening VtA and the transient target opening VtB is determined based on the target fuel injection amount differential value Q'.

Although the embodiments of the present invention have been described in detail above, other embodiments of the present invention are also possible.

(1) For example, the shape (gradient, etc.) of the diagram of each of the illustrated maps can be changed as appropriate.

(2) The engine is not limited to a supercharged engine, and may be a naturally aspirated engine.

(3) In the above embodiment, the transient D term VdB is calculated using the change amount of the target fuel injection amount Q per unit time, but the fuel injection amount actually injected from the injector 7, that is, the actual injection amount is detected. If there is a sensor or the like, the transient D term VdB may be calculated using the amount of change in the actual injection amount per unit time. Similarly, it may be determined whether or not the operating state of the engine 1 is a transient operating state (step S108 in FIG. 2) by using the amount of change in the actual injection amount per unit time.

The embodiment of the present invention is not limited to the above-described embodiment, and all modifications, applications, and equivalents included in the idea of the present invention defined by the scope of claims are included in the present invention. Therefore, the present invention should not be construed in a limited manner and can be applied to any other technique belonging within the scope of the idea of the present invention.

1 Internal combustion engine (engine)
16 Intake throttle valve 100 Electronic control unit (ECU)

Claims (2)

A control device for controlling an internal combustion engine, wherein the internal combustion engine has an intake throttle valve, and the control device has a control unit configured to control the intake throttle valve.
The control unit is configured to feedback-control the opening degree of the intake throttle valve by PID control based on the target intake pressure and the actual intake pressure.
The control unit
The first target of the intake throttle valve including the first D term of PID control calculated based on the difference between the change amount of the target intake pressure per unit time and the change amount of the actual intake pressure per unit time. The opening degree and the second target opening degree of the intake throttle valve including the second D term of PID control calculated based on the amount of change in the fuel injection amount per unit time are calculated.
The first target opening and the second target opening are changed while changing the weighting between the first target opening and the second target opening according to the degree of transient operation of the internal combustion engine. based on, it is configured to calculate a final target opening degree of the intake throttle valve,
The control unit is a control device for an internal combustion engine, characterized in that the higher the degree of transient operation of the internal combustion engine, the greater the weighting of the second target opening degree . Wherein the control unit, the weighting of the first target opening degree and the second target opening degree, to claim 1, wherein the determining based on the amount of change per the fuel injection quantity unit of time The control device for an internal combustion engine described.

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