JP2000110637A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress dispersion of an intake air volume caused by atmospheric pressure by regulating an opening of a flow rate control valve so as to increase the opening relating to the atmospheric pressure, in a device wherein the intake air volume is increased and an ignition timing is corrected to lagg. when an idling operation is performed after start. SOLUTION: When an internal combustion engine 1 is cranked, a starter motor is driven. When completed explosion is confirmed, a mode is transferred to an operating mode (a FIRE mode) in order to activate a catalyst device 3 in an early stage while performing an idling operation of the internal combustion engine 1, by a controller 2. An intake air volume supplied to the internal combustion engine 1 is increased more than that at the time of a normal idling operation by operating an opening of a flow rate control valve interposed in a bypass passage for bypassing a throttle valve through an actuator 24, in the FIRE mode. In this time, the opening is regulated so as the more to increase the opening as the more reducing the atmospheric pressure. An ignition timing is corrected to a phase lag side so as to converge engine rotating speed to target rotating speed simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In general, a catalyst device such as a three-way catalyst provided in an exhaust system of an internal combustion engine for purifying exhaust gas of the internal combustion engine has a certain rise in temperature and is not activated. In addition, it is difficult to secure required purification performance of exhaust gas. For this reason, securing the purification performance of exhaust gas immediately after the start of the internal combustion engine in which the catalyst device has a relatively low temperature has been a more important issue than before.

The applicant of the present application has proposed a technology for solving such a problem in Japanese Patent Application No. 9-109197 or Japanese Patent Application No. 10-10326, and the outline of this technology is as follows. It is.

[0004] That is, during the first idling operation after the start of the internal combustion engine, the amount of intake air taken into the combustion chamber of the internal combustion engine is reduced during normal idling operation (for example, during idling operation after traveling of a vehicle equipped with the internal combustion engine). The opening degree of a flow control valve (specifically, a throttle valve or a control valve of a bypass passage that bypasses the throttle valve) provided in the intake air passage of the internal combustion engine is operated so as to increase the opening amount.
Further, after the increase in the intake air amount is started, the rotation speed (actual rotation speed) of the internal combustion engine, which is increasing due to the increase, is converged to a required target rotation speed for idling operation immediately after the start of the internal combustion engine. The ignition timing of the internal combustion engine is operated by feedback control, whereby the ignition timing is corrected to a more retarded side than usual.

[0005] By increasing the intake air amount of the internal combustion engine and operating the ignition timing to the retard side, the calorific value of the exhaust gas generated by the internal combustion engine is increased, and the catalyst which is warmed by the exhaust gas is increased. The device activates early. As a result, the required purification performance of the catalyst device can be ensured at an early stage after the start of the internal combustion engine.

In this technique, the rotational speed of the internal combustion engine, which tends to increase as a result of an increase in the intake air amount of the internal combustion engine, is feedback-controlled to a target rotational speed, so that the rotational speed of the internal combustion engine is stabilized. Therefore, the operation of the intake air amount and the operation of the ignition timing can be performed independently of each other. Therefore, the construction of these control systems becomes easy and the control systems can be simplified.

In this technique, the opening degree of the flow control valve during the increase of the intake air amount is such that the operation after the start of the internal combustion engine is performed as smoothly and in a good combustion state as possible, Is set so that the amount of heat that can sufficiently activate the catalyst device within the required time can be given to the catalyst device. In this case, it is assumed that the actual intake air amount of the internal combustion engine is uniquely determined by the opening degree of the flow control valve, and the magnitude of the command value of the opening degree and the form of temporal change are determined in advance. The opening of the flow control valve is operated according to the command value.

However, the actual intake air amount of the internal combustion engine is affected by the atmospheric pressure even if the opening of the flow control valve is constant, and the higher the atmospheric pressure is, the more the actual intake air amount of the internal combustion engine is increased. Will increase. Further, although smaller than the influence of the atmospheric pressure, the actual intake air amount of the internal combustion engine is also affected by the atmospheric temperature, and the higher the atmospheric temperature, the smaller the density of the intake air. The amount of air is reduced. Therefore, the calorific value of the exhaust gas generated by the internal combustion engine according to the intake air amount is also affected by the atmospheric pressure and the atmospheric temperature. As a result, in an environment where the atmospheric pressure and the atmospheric temperature are different, when the opening degree of the flow control valve is operated as described above regardless of the atmospheric pressure and the atmospheric temperature, the amount of heat applied to the catalyst device varies, and as a result, Variations in the temperature rise and activation of the catalyst device may occur, and in some cases, the temperature rise and activation of the catalyst device may be insufficient to ensure sufficient purification performance.

[0009]

SUMMARY OF THE INVENTION In view of the foregoing, the present invention has been developed in consideration of the amount of intake air of an internal combustion engine based on atmospheric pressure and atmospheric temperature.
Eventually, it compensates for variations in the amount of heat applied to the catalyst device,
An object of the present invention is to provide a control device for an internal combustion engine that can perform a desired temperature rise and activation of a catalyst device regardless of the atmospheric pressure or the atmospheric temperature.

[0010]

In order to achieve the above object, a control apparatus for an internal combustion engine according to the present invention achieves the above object by controlling the intake air amount of the internal combustion engine during idling operation after the start of the internal combustion engine that discharges exhaust gas through a catalytic device. Means for operating an opening of a flow control valve provided in an intake air passage of the internal combustion engine so as to increase the amount by a predetermined amount from that during a normal idling operation; An ignition timing operating means for operating the ignition timing of the internal combustion engine by feedback control so as to converge the engine rotation speed to a predetermined target rotation speed and correcting the ignition timing to a retard side. In the control device, a means for adjusting the opening of the flow control valve when the amount of the intake air is increased according to the atmospheric pressure so that the opening is increased as the atmospheric pressure is lower is controlled by the intake air amount operation. By means And it said that there were pictures.

According to the present invention, the opening degree of the flow control valve when the intake air amount of the internal combustion engine is increased is adjusted according to the atmospheric pressure so that the opening degree increases as the atmospheric pressure decreases. This makes it possible to compensate for variations in the amount of intake air of the internal combustion engine due to the atmospheric pressure and, consequently, the amount of heat applied to the catalyst device. That is, when increasing the intake air amount of the internal combustion engine, when the flow control valve is operated to a certain opening degree, the actual intake air amount becomes smaller as the atmospheric pressure is lower. By adjusting the degree according to the atmospheric pressure, it is possible to make the intake air amount of the internal combustion engine a desired intake air amount (an intake air amount that is increased by a predetermined amount compared to a normal idling operation) regardless of the atmospheric pressure. it can. This allows
ADVANTAGE OF THE INVENTION According to this invention, desired temperature rise and activation of a catalyst device can be performed irrespective of atmospheric pressure, and, as a result, required purification performance of a catalyst device can be reliably ensured.

Further, according to the present invention, there is provided means for adjusting the opening of the flow control valve when the intake air amount is increased in accordance with the atmospheric temperature so that the opening increases as the atmospheric temperature increases. The intake air amount operation means is provided.

That is, when increasing the intake air amount of the internal combustion engine, when the flow control valve is operated to a certain opening degree, the actual intake air amount decreases as the atmospheric temperature increases, so that the flow control The opening degree of the valve is adjusted in accordance with the ambient temperature so that the opening degree increases as the ambient temperature increases.
As a result, the intake air amount of the internal combustion engine can be set to a desired intake air amount (an intake air amount that is increased by a predetermined amount compared to the normal idling operation) regardless of the atmospheric pressure and the atmospheric temperature. Intake air volume of the internal combustion engine according to temperature,
As a result, it is possible to compensate for variations in the amount of heat applied to the catalyst device. As a result, according to the present invention, it is possible to increase the temperature of the catalyst device without depending on the atmospheric pressure or the atmospheric temperature.
Activation can be performed more reliably, and the required purification performance of the catalyst device can be more reliably secured.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows the overall system configuration of the apparatus according to the present embodiment, wherein 1 is an internal combustion engine, and 2 is a controller for controlling the operation of the internal combustion engine 1.

The internal combustion engine 1 is mounted on a vehicle such as an automobile or a hybrid vehicle as a propulsion source. The internal combustion engine 1 generates exhaust gas generated by burning a mixture of fuel and air using, for example, a three-way catalyst. It is released to the atmosphere via the catalyst device 3 thus prepared.

FIG. 2 schematically shows an intake system of the internal combustion engine 1. As shown in FIG. 2, the combustion chamber 4 of the internal combustion engine 1 has a main intake passage 6 provided with a throttle valve 5 and a bypass valve 7 connected to the main intake passage 6 bypassing the throttle valve 5. The air can be sucked in through the bypass passage 8 provided with the air. In FIG. 2, 9 is a cylinder, 10 is a piston, 11 and 12 are intake and exhaust valves, respectively, and 13 is a chamber.

Returning to the description of FIG. 1, in the system of this embodiment, as an additional configuration for controlling the operation of the internal combustion engine 1, the rotation speed Ne (actual rotation speed) of the internal combustion engine 1 and the engine temperature Tw ( For example, the rotational speed sensor 14 and the engine temperature sensor 15 for detecting the cooling water temperature, respectively, and the internal pressure of the main intake passage 6 downstream of the throttle valve 5 and the bypass valve 7 (in this embodiment, the internal pressure of the chamber 13 in FIG. 2). An intake pressure sensor 16 for detecting a certain intake pressure Pb, an atmospheric temperature T
temperature sensor 1 for detecting a and atmospheric pressure Pa, respectively
7, an atmospheric pressure sensor 18, an operation amount Ap of an accelerator pedal (not shown) of a vehicle (hereinafter, referred to as an accelerator operation amount Ap).
, And various sensors such as an accelerator sensor 19 and a vehicle speed sensor 20 for detecting the vehicle speed V, respectively.

Further, as an additional configuration for driving the internal combustion engine 1, an ignition device 21 for igniting the air-fuel mixture in the combustion chamber 4, a fuel supply device 22 for supplying fuel to the combustion chamber 4, the throttle valve 5, A throttle valve actuator 23 and a bypass valve actuator 24 for operating the bypass valve 7 are provided.

Although illustration is omitted, in addition to the above configuration,
A starter motor for starting the internal combustion engine 1, a power supply battery for various electronic devices, and a transmission for transmitting the power of the internal combustion engine 1 to the drive wheels (automatic transmission in the system of the present embodiment)
Etc. are also provided.

The controller 2 is constituted by using a microcomputer, and has the various sensors 14 described above.
20 through an ignition device 21, a fuel supply device 22, a throttle valve actuator 23, a bypass valve actuator 24, and the like, based on output (detection value) data, a predetermined program, and a preset data value. The required operation of 1 is performed.

The controller 2 controls the opening degree of the throttle valve 5 or the bypass valve 7 via the throttle valve actuator 23 and the bypass valve actuator 24, thereby controlling the amount of intake air in the combustion chamber 4 of the internal combustion engine 1. And an ignition timing control means 26 for controlling the ignition timing of the internal combustion engine 1 via the ignition device 21.

The details of the functions of these means 25 and 26 will be described later, but the ignition timing operating means 26 has a function as a rotation speed control device according to the present invention. The valve 7 and the bypass passage 8 correspond to the flow control valve and the intake air passage according to the present invention, respectively. In the present embodiment, a control cycle (control cycle) in which the controller 2 executes the control process is a crank angle cycle (so-called TDC).

Next, the operation of the system according to the present embodiment will be described together with the functions of the intake air amount operation means 25 and the ignition timing operation means 26 of the controller 2.

First, an outline of the basic operation of the system according to the present embodiment will be briefly described with reference to FIG. FIG. 3 shows exemplary forms of the temporal change of the opening degree of the bypass valve 7 (hereinafter referred to as “bypass opening degree”), the ignition timing, and the rotational speed during the operation from the start of the internal combustion engine 1 to the idling operation, respectively. These are shown in the middle and lower sections.

Referring to FIG. 3, in the system according to the present embodiment, when the system is started by operating a start switch (not shown) while the operation of the internal combustion engine 1 is stopped, the system first operates. 1 is performed by a starter motor (not shown).
(Hereinafter, referred to as a start mode). In this start mode, the bypass opening and the ignition timing are respectively operated as shown, and the rotation speed Ne of the internal combustion engine 1 fluctuates as shown.

In the system of the present embodiment, the opening of the throttle valve 5 during operation of the internal combustion engine 1 is determined according to the accelerator operation amount Ap, and an accelerator pedal (not shown) is operated. In the state where the throttle valve 5 is not operated (Ap = 0. This state is the idling operation state of the internal combustion engine 1 while the vehicle is stopped), the opening of the throttle valve 5 is “0” (the closed state of the throttle valve 5). ). And
In this state, the intake of the combustion chamber 4 is performed only through the bypass passage 8. FIG. 3 shows the bypass passage 8 as described above.
This is related to the case where the intake of the combustion chamber 4 is performed only through this.

When the so-called complete explosion of the internal combustion engine 1 is confirmed in the start mode, the operation of the system is performed in an operation mode for early activation of the catalyst device 3 while performing idling operation of the internal combustion engine 1 ( (Hereinafter referred to as FIRE mode).

In the FIRE mode, for example, in the form of a temporal change (pattern) as shown in the upper part of FIG. 3, a command for a bypass opening degree larger than during a normal idling operation (during idling operation other than the FIRE mode). Value θCM
Generate D sequentially. By operating the bypass opening through the bypass valve actuator 24 in accordance with the command value θCMD, the amount of intake air in the combustion chamber 4 of the internal combustion engine 1 is increased as compared with the normal idling operation.

In this case, the operation in the FIRE mode is basically the elapsed time t / fire since the start of the operation (this is the elapsed time since the start of increasing the intake air amount). Hereinafter, the FIRE elapsed time t / fire is set to a predetermined time limit TFIELMT (hereinafter, FIRE mode time limit TFIELL).
MT).

The command value θCMD of the bypass opening in the FIRE mode is basically the same as the FIRE mode.
The exhaust gas having a calorific value capable of appropriately performing the desired temperature rise and activation of the catalyst device 3 within the RE mode time limit TFIRELMT (the calorific value of the exhaust gas is generally proportional to the intake air amount of the combustion chamber 4 of the internal combustion engine 1) Can be supplied to the device 3 and the FIR
The setting is made such that the idling operation of the internal combustion engine 1 can be performed stably and smoothly while the combustion state and the emission state of the internal combustion engine 1 in the E mode are kept good.

With the increase of the intake air amount (the increase of the bypass opening) in the FIRE mode, the rotation speed Ne (actual rotation speed) of the internal combustion engine 1 immediately after the start of the increase is shown in FIG.
In the form shown by the solid line in the lower part of FIG. When the rotational speed Ne reaches a set rotational speed (NOBJ + NEFSLDS) higher by a predetermined amount NEFSLDS than an idling rotational speed NOBJ (constant) predetermined as an appropriate rotational speed to be finally maintained in the FIRE mode, the internal combustion engine is started. The feedback timing for converging the engine speed Ne of the engine 1 to the required target engine speed ne / fire controls the ignition timing of the internal combustion engine 1 as shown by the solid line in the middle part of FIG. Hereinafter, this feedback control of the rotation speed Ne is referred to as ignition timing operation rotation speed F / B control. The ignition timing operation speed F / B control is performed when the speed Ne of the internal combustion engine 1 reaches the set speed (NOBJ + NEFSLDS) and also when the FI is set.
RE elapsed time t / fire is predetermined value TSLDIGST
(See the lower part of FIG. 3).

In this ignition timing operation speed F / B control,
The target rotational speed ne / fire of the internal combustion engine 1 is set in the form shown by the broken line in the lower part of FIG. The target speed ne / fire
Is reduced toward the idling rotational speed NOBJ from the set rotational speed (NOBJ + NEFSLDS) at a predetermined degree of decrease (slope), and after reaching the idling rotational speed NOBJ, is held at the idling rotational speed NOBJ. The idling rotational speed NOBJ is set to a rotational speed higher than the rotational speed during normal idling operation.

In the ignition timing operation speed F / B control, a feedback control process is performed to converge the speed Ne (actual speed) of the internal combustion engine 1 to the target speed ne / fire set in this manner. In the middle stage of FIG. 3, a correction amount DIG of the ignition timing as shown by the broken line (this correction amount DIG is an ignition timing deviation command value to be described later) is obtained, and the basic command value igbase (FIG. The command value iglog of the ignition timing is determined by compensating for the ignition timing. Here, the basic command value igbase of the ignition timing is determined during normal operation of the internal combustion engine 1 (during operation other than the FIRE mode).
And is a value on the advance side.

In the ignition timing operation speed F / B control, the command value ig obtained by correcting the basic command value igbase as described above is used.
The ignition timing of the internal combustion engine 1 is determined according to the log
Through the engine, the rotational speed Ne of the internal combustion engine 1 is set to the target rotational speed ne / fire (eventually, the idling rotational speed NO
Feedback control to BJ).

At this time, the rotation speed Ne of the internal combustion engine 1 tends to increase with respect to the target rotation speed ne / fire due to the above-described increase in the intake air amount.
The correction amount DIG obtained by the control is for correcting the ignition timing to the retard side from the basic command value igbase. Therefore, the ignition timing iglog obtained by correcting the basic command value igbase with the correction amount DIG (≦ 0) is on the retard side as shown by the solid line in the middle stage of FIG.

As described above, the FIRE mode performed at the time of the first idling operation after the start of the internal combustion engine 1 is such that the intake air amount is increased by the operation of the bypass opening degree and the ignition is performed by the ignition timing operation speed F / B control. By controlling the rotation speed Ne of the internal combustion engine 1 to a required target rotation speed ne / fire (eventually, an idling rotation speed NOBJ) by operating the timing to the retard side, the internal combustion engine 1 causes the combustion chamber 4 to rotate. Thus, the calorific value of the exhaust gas generated by the combustion of the air-fuel mixture is made larger than in the normal idling operation. Then, by supplying the exhaust gas having such a large amount of heat to the catalyst device 3, the temperature rise and activation of the catalyst device 3 is accelerated, and the required exhaust gas purification performance of the catalyst device 3 is secured early. .

In the FIRE mode in which the intake air amount is increased and the ignition timing operation speed F / B is controlled, the FIRE process is executed except when the accelerator pedal of the vehicle is operated during the operation. The operation is continuously performed until the time t / fire reaches the FIRE mode limit time TFIRELMT, and thereafter, the operation of the system shifts to a mode for performing a normal operation of the internal combustion engine 1 (hereinafter, referred to as a normal mode). In the normal mode, the bypass opening is set to, for example, the internal combustion engine 1.
Opening (<FI) for normal idling operation of
The bypass opening in RE mode. (See the right part in the upper part of FIG. 3). The ignition timing of the internal combustion engine 1 is gradually returned to the normal advance ignition timing determined by the basic command value igbase after the end of the FIRE mode, as shown in the right part of the middle part of FIG. .

In the system of this embodiment, the FI
During RE mode operation (FIRE elapsed time t / fire is FIR
Before the E-mode time limit TFIRELMT is reached), an accelerator pedal (not shown) is operated to start / run the vehicle or to perform a so-called flicking operation of the internal combustion engine 1, and the operation of the internal combustion engine 1 other than idling is performed. Is performed, the FIRE mode interruption operation is performed.

In this interruption operation, the amount of intake air is continuously increased by the operation of the bypass opening as described above in order to ensure that the temperature of the catalyst device 3 is increased and activated. However, in order to ensure the required power performance of the internal combustion engine 1, the ignition timing is returned to the normal advance ignition timing determined by the basic command value igbase (ignition timing operation speed F / B control is performed). Interrupted). Then, when the idling operation of the internal combustion engine 1 is again performed within the FIRE mode time limit TFIRELMT, the ignition timing operation speed F / B control is restarted. That is, the interruption operation of the FIRE mode is basically an operation of interrupting the ignition timing operation speed F / B control. However, regarding the increase in the intake air amount due to the operation of the bypass opening, the partial control processing related to the increase is also interrupted.

The contents described above are the outline of the basic operation of the system of this embodiment.

Next, the detailed operation of the system according to the present embodiment will be described below in consideration of such a basic operation.

When the system of the present embodiment is started with the operation of the internal combustion engine 1 stopped, the controller 2 executes the main routine shown in the flowchart of FIG. 4 in a predetermined control cycle, that is, a crank angle cycle (TDC). .

The controller 2 first determines whether the operation mode of the system is the start mode (ST).
EP4-1). This determination is made, for example, based on whether or not a so-called complete explosion of the internal combustion engine 1 has been confirmed. After the system is started, the operation mode is the start mode until the complete explosion is confirmed. The completion of the explosion is confirmed based on the output of the rotation speed sensor 14 (detected value of the rotation speed Ne).

If it is determined in STEP 4-1 that the operation mode is the start mode, the controller 2 executes a start mode process for starting the internal combustion engine 1 for each control cycle (STEP 4-2).

In this start mode process, the controller 2 sets the proper ignition timing for starting the internal combustion engine 1;
The fuel supply amount and the command value of the bypass opening are determined based on the outputs (detected values) of the various sensors 14 to 20 described above, predetermined maps, arithmetic expressions, and the like. The ignition device 21 and the fuel supply device 2
2, while operating the ignition timing, fuel supply amount, and bypass opening (intake air amount) via the bypass valve actuator 24, and cranking the internal combustion engine 1 by a starter motor (not shown). To start.

In the start mode process, the controller 2 initializes various parameters (details will be described later) such as flags used in the control process in the FIRE mode.

Further, in the start mode processing, the internal combustion engine 1
Engine temperature Tw, atmospheric temperature Ta and atmospheric pressure Pa at the start of
Are respectively detected by the engine temperature sensor 15, the atmospheric temperature sensor 17, and the atmospheric pressure sensor 18 and stored in a memory (not shown).

On the other hand, if the operation mode is not the start mode (if the complete explosion of the internal combustion engine 1 is confirmed), the controller 2 sends the control signal to the internal combustion engine 1 every control cycle. A command value of the fuel supply amount is generated (STEP 4-3). In addition, the controller 2
After making a condition determination as to whether or not to perform the control process in the RE mode (whether the operation mode is the FIRE mode or the normal mode) (STEP 4-4), the command value θCMD of the bypass opening is changed to the intake air. It is generated by the quantity operation means 25 (STEP 4-5), and a command value iglog of the ignition timing of the internal combustion engine 1 is generated by the ignition timing operation means 26 (STEP 4-6).

In the process of generating the command value of the fuel supply amount in STEP 4-3, first, the rotation speed Ne (actual rotation speed) and the intake pressure of the internal combustion engine 1 detected by the rotation speed sensor 14 and the intake pressure sensor 16 are detected. From Pb, the basic fuel supply amount is obtained based on a predetermined map. Then, the basic fuel supply amount is determined by the engine temperature T detected by the engine temperature sensor 15 or the atmospheric temperature sensor 17.
By performing correction in accordance with w, the atmospheric temperature Ta, and the like, a command value of the fuel supply amount corresponding to the intake air amount of the combustion chamber 4 of the internal combustion engine 1 is generated.

The command value of the fuel supply amount generated in this manner is provided from the controller 2 to the fuel supply device 22 for each control cycle, and the fuel supply device 22 operates according to the provided command value. Supply fuel to the plant.

The processing of the condition determination in the above STEP4-4 is performed as shown in the flowchart of FIG.

That is, the controller 2 first determines whether or not the current FIRE elapsed time t / fire is within the FIRE mode limit time TFIRELMT (whether or not t / fire <TFIRELMT; STEP 5-1). The engine temperature sensor 1 determines whether or not the current rotational speed Ne detected by the rotational speed sensor 14 is within a normal predetermined range (STEP 5-2).
It is sequentially determined whether or not the current engine temperature Tw detected in Step 5 is within a normal predetermined range (STEP 5-3).
The FIRE elapsed time t / fire determined in STEP 5-1
Is initialized to “0” in the start mode process (STEP 4-2), and is counted from the time when the start mode ends (the control cycle in which the complete explosion of the internal combustion engine 1 is confirmed).

When the conditions of STEPs 5-1 to 5-3 are not satisfied, that is, when the FIRE elapsed time t / fire has already reached the FIRE mode limit time TFIRELMT, or when the current rotational speed of the internal combustion engine 1 If Ne is an abnormally high or low rotational speed, or if the current engine temperature Tw of the internal combustion engine 1 is an abnormally high or low temperature, the controller 2 performs a learning operation to be described later. A flag f / flrnend (hereinafter referred to as a learning calculation end flag f / flrnend) indicating whether or not to end the related processing (calculation processing of a basic learning correction coefficient vpskisld described later) by values “1” and “0”, respectively. Is determined (STEP 5-4). Then, the controller 2 executes f / fl
Current FIRE elapsed time only if rnend = 0
The value of t / fire is held as the value of the parameter t / kil (STEP5-5), and the learning calculation end flag f / flrn
The value of end is set to "1" (STEP 5-6). Here, the parameter t / kil is a basic learning correction coefficient vp
FIRE elapsed time t / fi at the end of skisld calculation
It represents re. Hereinafter, the parameter t / kil is referred to as a learning end time parameter t / kil.

The values of the learning calculation end flag f / flrnend and the learning end time parameter t / kil are initialized to "0" in the start mode process (STEP 4-2).

Next, the controller 2 forcibly sets the value of the FIRE elapsed time t / fire to the FIRE mode limit time TFIR.
After fixing to ELMT (STEP 5-7), a flag f / fpause (hereinafter referred to as FIRE interruption) indicating whether or not the interruption operation as described above in the FIRE mode is to be performed is indicated by values “1” and “0”, respectively. Flag f / fpause) and FI
A flag f / fireon (hereinafter referred to as FI) indicating whether or not the operation in the RE mode is to be performed is indicated by values “1” and “0”, respectively
The value of the RE execution feasibility flag f / fireon) is set to "0" (STEPs 5-8 and 5-9), and the process returns to the main routine of FIG. The fact that the operation in the FIRE mode is not to be performed (f / fireon = 0) means that the operation in the normal mode is to be performed.

On the other hand, when the conditions in STEPs 5-1 to 5-3 are satisfied, the controller 2 determines whether or not the accelerator pedal of the vehicle is operated based on the output of the accelerator sensor 19 (accelerator operation amount Ap). (STEP5-
10) It is sequentially determined whether or not the fuel cut of the internal combustion engine 1 is being performed (STEP 5-11). The internal combustion engine 1
The fuel cut is a process of cutting off the fuel supply when the vehicle is running at a reduced speed. When the accelerator pedal of the vehicle is operated, the controller 2 operates the throttle valve 5 through the throttle valve actuator 23 to an opening corresponding to the accelerator operation amount Ap.

At this time, if none of the conditions of STEPs 5-10 and 5-11 are satisfied, the internal combustion engine 1 is basically in a state of idling operation. In this case, the controller 2 sets the FIRE interruption flag f / fpau
After the value of se is set to "0" (STEP 5-12), the value of the FIRE execution enable / disable flag f / fireon is set to "1" (STEP 5-13), and the process returns to the main routine of FIG. I do.

When any one of the conditions in STEPs 5-10 and 5-11 is satisfied, the controller 2 sets F
After the value of the FIRE interruption flag f / fpause is set to “1” in order to perform the interruption operation of the IRE mode (STEP 5-1)
4), the value of the learning calculation end flag f / flrnend is determined (STEP 5-15). And the controller 2
Only when f / flrnend = 0, the current value of the FIRE elapsed time t / fire is held as the value of the learning end time parameter t / kil (STEP 5-16), and the learning operation end flag f / flrnend is set. Set the value to “1” (STE
P5-17).

Next, the controller 2 sets the value of a countdown timer cnt / igvpl used for the ignition timing operation process (details will be described later) after the end of the interruption operation of the FIRE mode to a predetermined initial value XCNT (STEP 5). -1
8) After step 5-13, the process returns to the main routine of FIG.

A situation in which any one of the conditions in STEPs 5-10 and 5-11 is satisfied, that is, a situation in which the value of the FIRE suspend flag f / fpause is set to “1” in order to perform the suspend operation in the FIRE mode is as follows. Basically, within the FIRE mode time limit TFIRELMT, the vehicle is starting or running by operating the accelerator pedal of the vehicle (the internal combustion engine 1 is driving its load), or In this state, the internal combustion engine 1 is being idled. However, when the vehicle is started within the FIRE mode time limit TFIRELMT and during the subsequent deceleration running of the vehicle, STEP 5
Neither -10 nor 5-11 may be satisfied. In other words, the situation in which the FIRE mode is interrupted
To be more precise, the situation is such that an operation other than the idling operation of the internal combustion engine 1 is performed while the air-fuel mixture is being burned.

By the above-described processing of the condition determination in STEP 4-4, after the internal combustion engine 1 is started (after the start mode is completed), as long as the rotation speed Ne and the engine temperature Tw of the internal combustion engine 1 are within appropriate ranges. Until the FIRE elapsed time t / fire reaches the FIRE mode time limit TFIRELMT, the operation mode of the system is set to the FIRE mode (f / fire).
on = 1). In the state in which the FIRE mode is set, basically, the increase in the intake air amount and the ignition timing operation rotation speed F by the operation of the bypass opening as described above, except during the interruption operation of the FIRE mode. / B control is performed in parallel.

In a situation where the rotational speed Ne or the engine temperature Tw of the internal combustion engine 1 is abnormally high or low for some reason, the operation mode of the system changes from the immediately after the start of the internal combustion engine 1 to the normal mode. It is set, or the FIRE mode is canceled (terminated) halfway and the normal mode is set (f / fireon = 0). When the normal mode is set, the bypass opening and the ignition timing are controlled to the bypass opening and the ignition timing for performing the normal operation of the internal combustion engine 1 (operation other than the FIRE mode). . Furthermore, when the normal mode is set,
In step 5-7, the value of the FIRE elapsed time t / fire is forcibly fixed to the FIRE mode limit time TFIRELMT.
The condition of TEP5-1 is not satisfied (the FIRE elapsed time t / fire is initialized only in the start mode). Therefore, the FIRE mode is set only during the period from the start of the internal combustion engine 1 to the elapse of the FIRE mode limit time TFIRELMT.

In a state where the operation mode of the system is set to the FIRE mode (f / fireon = 1), the operation of the accelerator pedal allows the vehicle to run, or the internal combustion engine 1 to be idled. In such a case, that is, when the operation of the internal combustion engine 1 other than the idling operation should be performed (when any of the conditions in STEPs 5-10 and 5-11 is satisfied), the FIRE interruption flag f / fpause is set to “ 1 ". In this case, the intake air amount is increased by operating the bypass opening as described above, but the F / B control for interrupting the ignition timing operation rotational speed F / B is interrupted.
The interruption operation of the IRE mode is performed. Then, in a state where the operation mode is the FIRE mode and the interruption operation is being performed (f / fireon = 1 and f / fpause = 1), any of the conditions of STEPs 5-10 and 5-11 is not satisfied, FIRE suspension flag f / fpause is "0"
(This is basically the case of restarting the idling operation), the suspension operation is released, and the ignition timing operation speed F / B control is restarted.

It should be noted that the FIRE is operated by operating the accelerator pedal.
In a situation where the mode interruption operation is performed (the condition of STEP 5-10 is satisfied), the opening of the throttle valve 5 is set to a value corresponding to the accelerator operation amount Ap (> 0). For this reason, in this situation, the intake air is taken into the combustion chamber 4 of the internal combustion engine 1 through both the bypass valve 7 and the throttle valve 5.

Although not adopted in this embodiment,
The operation mode of the system may not be set to the FIRE mode until a short time has elapsed after the start mode has ended.

Next, the generation processing of the command value θCMD of the bypass opening in STEP4-5 in FIG. 4 will be described.

Here, before describing the specific contents of this processing in detail, the basic contents of this processing will be described.

In the system of the present embodiment, as a main process performed by the intake air amount operating means 25 of the controller 2 to generate the bypass opening command value θCMD in the FIRE mode, a standard bypass opening command value θ0 ( Less than,
A process for generating a standard opening command value θ0) (hereinafter referred to as a standard opening command value generation process), and the integrated value of the actual intake air amount of the combustion chamber 4 of the internal combustion engine 1 is made to converge to a required target value. For correcting the bypass opening command value by the feedback control process (hereinafter, the intake air amount F / B
The correction amount of the bypass opening command value by the intake air amount F / B control correction process is learned each time the FIRE mode operation is performed, and based on the learning result, the next FIRE mode correction is performed. A process for correcting the command value of the bypass opening during operation (hereinafter referred to as a learning correction process), and the atmospheric pressure sensor 18 and the atmospheric temperature sensor 17
Pressure and atmospheric temperature Ta respectively detected by
(Hereinafter referred to as atmospheric condition correction processing), and the bypass opening degree is corrected according to the ignition timing operated by the ignition timing operation rotation F / B control. There is a process for correcting the command value (hereinafter, referred to as an ignition timing responsive correction process). The basic contents of these processes will be described below.

First, the standard opening command value generation processing will be described.

In the system of the present embodiment, the main purpose of increasing the intake air amount in the FIRE mode is to raise and activate the catalyst device 3 at an early stage.
The exhaust gas having a calorific value (the calorific value of the exhaust gas is approximately proportional to the amount of the intake air into the combustion chamber 4 of the internal combustion engine 1) can be catalyzed by the exhaust gas having a calorific value capable of reliably performing a desired temperature rise and activation of the catalyst device 3 within the RE mode time limit TFILIMT It is necessary to increase the amount of intake air so that it can be supplied to the device 3.

On the other hand, this increase in the intake air amount is started immediately after the internal combustion engine 1 is started, and the ignition timing is retarded from the normal ignition timing by the ignition timing operation speed F / B control. Since the operation is performed while the intake air amount is being increased, if the amount of increase in the amount of intake air (the pattern of a temporal change in the amount of increase) is inappropriate, the combustion state and emission state of the internal combustion engine 1 may be impaired. Therefore, it is necessary to increase the amount of intake air in the FIRE mode so that the idling operation of the internal combustion engine 1 can be performed stably and smoothly without impairing the combustion state and the emission state of the internal combustion engine 1 in the FIRE mode. There is.

For this reason, in the standard opening command value generation processing, the standard opening command value θ0 which is the basis of the command value of the bypass opening to be given to the bypass valve actuator 24 for increasing the intake air amount. Is generated in a feed-forward manner for each control cycle (TDC) according to the engine temperature Tw at the time of starting the internal combustion engine 1 (starting mode), the FIRE elapsed time t / fire, and the like.

The standard opening command value generation processing is performed as follows.

First, when starting the internal combustion engine 1 (start mode)
The engine temperature T detected by the engine temperature sensor 15
From w, a basic value i / ftbl of the standard opening command value θ0 (this is the maximum value of the standard opening command value θ0 during operation in the FIRE mode) is determined based on a predetermined data table.

In this case, in this embodiment, the basic value i /
ftbl is when the operation position (hereinafter referred to as shift position) of the operation lever of the automatic transmission (not shown) of the vehicle during the operation of the FIRE mode is in the N range (neutral range) and in the D range (drive range). And determine each different value.

That is, when the shift position of the automatic transmission is in the N range, the value ifiret (hereinafter referred to as N range) obtained from the engine temperature Tw at the start of the internal combustion engine 1 according to the data table of the solid line a in FIG. The basic value ifiret) is determined as the basic value i / ftbl of the standard opening command value θ0.

Here, the data table indicated by the solid line a basically indicates that the higher the engine temperature Tw, the more the N range basic value ifiret
Is set to be small. This means that the engine temperature Tw at the time of starting the internal combustion engine 1 corresponds to the initial temperature of the catalyst device 3, and the higher the temperature, the more heat required to perform a desired temperature increase and activation of the catalyst device 3, This is because the intake air amount of the internal combustion engine 1 can be reduced.

When the shift position of the automatic transmission is in the D range, the value ia obtained from the engine temperature Tw at the start of the internal combustion engine 1 according to the data table shown by the solid line b in FIG.
tfire (hereinafter, D range correction value iatfire) is added to the N range basic value ifiret to obtain a standard opening command value θ.
It is determined as a basic value i / ftbl of 0 (= ifiret + iatfire).

Here, the data table of the solid line b is basically such that the basic value fitbl in the D range is slightly higher than that in the N range at an arbitrary engine temperature Tw when the internal combustion engine 1 is started. Is set. This is because the load that absorbs the driving force of the internal combustion engine 1 is larger in the D range than in the N range, the rotation speed of the internal combustion engine 1 is easily reduced, and the calorific value of the exhaust gas is more than in the N range. It is because it becomes less.

In this embodiment, the engine temperature Tw at the start of the internal combustion engine 1 is used as the initial temperature of the catalyst device 3 (the temperature state of the catalyst device 3 at the start of the internal combustion engine 1). However, the initial temperature of the catalyst device 3 may be directly detected when the internal combustion engine 1 is started, and the basic value i / ftbl of the standard opening command value θ0 may be determined from the detected temperature in the same manner as described above.

In this embodiment, since the automatic transmission is employed in the vehicle, different basic values i / ftbl are set for the N range and the D range. When the engine is mounted on a vehicle, a single basic value i / ftbl is determined according to the engine temperature Tw (or the initial temperature of the catalyst device 3) at the time of starting the internal combustion engine 1 without making such a distinction. May be set in the same manner as described above.

While the basic value i / ftbl of the standard opening command value θ0 is determined in this manner, the standard opening command value generation processing further calculates the FIRE elapsed time t / fire as shown in FIG. A correction coefficient km / fire (≦ 1) for correcting the basic value i / ftbl (multiplication correction) according to a predetermined data table (time table) is obtained for each control cycle. Then, a value obtained by multiplying the basic value i / ftbl by the correction coefficient km / fire is used as a standard opening command value θ0 (=
i / ftbl ・ km / fire).

Here, in the data table of FIG.
In the initial stage of the RE mode (t / fire: 0 to t1), the standard opening command value θ0 is gradually increased toward the basic value i / ftbl in order to stabilize the combustion state of the internal combustion engine 1 immediately after starting. The correction coefficient km / fire is gradually increased toward “1” so as to increase. Then, the standard opening command value θ0
Has reached the basic value i / ftbl (after the correction coefficient km / fire has reached “1”), for a predetermined time (t / fire: t1)
-T2), the correction coefficient km / fire is set to "1" so that the standard opening command value θ0 is maintained at the basic value i / ftbl. After that (t / fire: t2 to TFIRELMT), the correction coefficient km / fire is gradually reduced so that the standard opening command value θ0 is gradually reduced. Thus, the standard opening command value θ
The reason why 0 is gradually reduced is as follows.

That is, when the internal combustion engine 1 warms up to some extent, the friction of each part of the internal combustion engine 1 is increased.
Gradually decreases, and the increasing tendency of the rotation speed Ne of the internal combustion engine 1 increases. As a result, the ignition timing operation rotation speed F /
The ignition timing of the internal combustion engine 1 operated by the B control shifts to a more retarded side. At this time, when the ignition timing of the internal combustion engine 1 reaches a limit value on the retard side where the ignition timing can be operated while the internal combustion engine 1 is operating normally, the rotation speed Ne of the internal combustion engine 1 is reduced. The upward trend cannot be suppressed. In order to prevent such a situation, after the FIRE elapsed time t / fire has reached the predetermined time t2 and the operation of the FIRE mode has progressed to some extent (after the internal combustion engine 1 has warmed up to some extent), the standard opening degree is set. The command value θ0 (the amount of intake air of the internal combustion engine 1) is gradually reduced to suppress the tendency of the rotational speed Ne to increase due to a decrease in friction.

The contents described above are the contents of the standard opening command value generation processing.

In the system of this embodiment, basically,
By operating the bypass opening in accordance with the standard opening command value θ0 generated in a feedforward manner as described above, the desired temperature increase and activation of the catalyst device 3 can be achieved while the operation of the internal combustion engine 1 is stably performed. It is possible to do it properly.

Next, the intake air amount F / B control correction process and the atmospheric condition correction process will be described.

In the present embodiment, the standard opening command value θ0 determined as described above in the standard opening command value generation processing
Is defined by a reference constant correlation between the actual opening degree of the bypass valve 7 and the actual intake air amount of the combustion chamber 4 of the internal combustion engine 1 with respect to the bypass opening command value given to the bypass valve actuator 24. And the atmospheric pressure Pa and the atmospheric temperature Ta are each set to a predetermined standard atmospheric pressure (for example, 1 atm),
It is determined based on ideal conditions such as a standard atmospheric temperature (for example, a normal temperature of 25 ° C.).

However, the actual opening degree of the bypass valve 7 or the actual intake air amount with respect to the bypass opening command value depends on variations in the operating characteristics of the bypass valve actuator 24 and the bypass valve 7 or changes in the characteristics over time. This causes variations (hereinafter, such variations in the intake air amount are referred to as variations due to structural factors).

Even if there is no variation due to the structural factors as described above, the actual intake air amount with respect to the bypass opening command value varies with the atmospheric pressure Pa. Further, although smaller than the influence of the atmospheric pressure Pa, the actual intake air amount with respect to the command value θCMD of the bypass opening also varies depending on the atmospheric temperature Ta (hereinafter, such an amount depends on the atmospheric pressure Pa and the atmospheric temperature Ta). Variations in the amount of intake air are called variations due to atmospheric conditions).

That is, when the bypass opening command value is fixed (bypass opening is fixed), the actual intake air amount decreases as the atmospheric pressure Pa decreases. Also, the atmospheric temperature T
Since the density of the air decreases as a increases, the actual intake air amount (mass of the intake air) decreases as the ambient temperature Ta increases.

When such a variation in the amount of intake air occurs, a variation in the amount of heat of the exhaust gas generated by the internal combustion engine 1 (which is substantially proportional to the amount of intake air) also occurs. Also occurs. For this reason, in some cases, it is not possible to reliably perform early temperature rise and activation of the catalyst device 3, which is the main purpose of increasing the intake air amount in the FIRE mode, and, consequently, during operation of the FIRE mode. May not be able to secure the required purification performance.

The intake air quantity F / B control correction processing and the atmospheric condition correction processing are processings performed to solve such inconveniences. Among them, the intake air quantity F / B control correction processing is
The process for compensating for variations due to the structural factors and the atmospheric condition correction process described above are processes for compensating for variations due to atmospheric conditions.

First, the intake air amount F / B control correction process for compensating for the variation due to the structural factors will be described.

The basic concept of the intake air amount F / B control correction processing is that, during operation in the FIRE mode, heat amount data representing the heat amount actually given to the catalyst device 3 by the exhaust gas of the internal combustion engine 1 is sequentially (control cycle). Each time, the value of the calorific value data is detected or estimated, and the value of the calorific value data is converged to a predetermined target value (this corresponds to the target calorific value to be given to the catalyst device 3). Correct the value. Then, by operating the bypass opening based on the corrected command value, the amount of heat actually given to the catalyst device 3 is matched with the target amount of heat corresponding to the target value of the value of the above-mentioned amount of heat data. In addition, the variation in the temperature rising mode of the catalyst device 3 is eliminated.

In this case, the calorie data representing the calorie given to the catalyst device 3 includes, for example, the amount of intake air or the amount of fuel supplied at each control cycle (instantaneous moment) (these are basically the control cycle given to the catalyst device 3). For each (instantaneous instantaneous) amount of heat, or their integrated value (this is proportional to the instantaneous instantaneous amount of heat applied to the catalytic device 3), or the temperature rise amount of the catalytic device 3 (the catalytic device 3 Is proportional to the integrated value of the amount of heat at the moment when the temperature rise amount from the initial temperature is given to the catalyst device 3).

In this embodiment, for example, an integrated value of the intake air amount is used as the heat amount data.
The integrated value of the actual intake air amount of the internal combustion engine 1 during the operation in the IRE mode is estimated for each control cycle as follows, and the target value of the integrated value is set for each control cycle as follows.

First, regarding the estimation of the integrated value of the intake air amount,
The intake air amount drawn into the combustion chamber 4 of the internal combustion engine 1 per TDC, which is a control cycle in the present embodiment, is generally proportional to the internal pressure of the chamber 13 shown in FIG. 2, that is, the intake pressure Pb.

Therefore, in the present embodiment, the estimated value gair / pre of the intake air amount for each control cycle is obtained by the following equation (1) (hereinafter, this estimated value gair / pre is calculated as the estimated intake air amount gair / p
re)).

[0101]

(Equation 1)

Here, the coefficient Ga1 in the equation (1) is a predetermined value (constant value) determined in advance.

Then, the estimated intake air amount gair / pre is
During the operation of the FIRE mode, the cumulative value qa of the intake air amount is obtained by accumulative addition for each control cycle according to the following equation (2).
ir / pre is calculated (hereinafter, this integrated value qair / pre is referred to as an estimated integrated intake air amount qair / pre).

[0104]

(Equation 2)

Here, k in the equation (2) is the number of the control cycle (the same applies hereinafter).

Incidentally, the integrated value of the actual intake air amount of the internal combustion engine 1 may be obtained by directly detecting the intake air amount for each control cycle by, for example, an air flow sensor or the like, and integrating the detected air amount. Good.

Next, the target value of the integrated value of the intake air amount corresponding to the target value of the integrated value of the amount of heat applied to the catalyst device 3 (hereinafter, referred to as the target value)
The target cumulative intake air amount qair / cmd) can be set in various forms in order to appropriately raise and activate the temperature of the catalyst device 3. However, the target value is FIR
Since this affects the intake air amount of the internal combustion engine 1 during the operation in the E mode, and furthermore, the combustion state and the emission state of the internal combustion engine 1, it is necessary to consider the operation stability of the internal combustion engine 1.

Therefore, in the present embodiment, it has been determined that the temperature of the catalyst device 3 is appropriately raised and activated under ideal conditions as described above, and that the internal combustion engine 1 can be operated stably. The target integrated intake air amount qair / cmd is set based on the standard opening command value θ0.

That is, the standard opening command value θ0 is the atmospheric pressure Pa and the atmospheric temperature Ta at which the actual bypass opening and the intake air amount are uniquely determined with respect to the bypass opening command value.
Are constant standard atmospheric pressure and standard atmospheric temperature, respectively.
Under such ideal conditions, the temperature of the catalyst device 3 is appropriately raised and activated, and the operation of the internal combustion engine 1 is set to be stable. In other words, the standard opening command value θ0 is the optimum intake air to be taken into the combustion chamber 4 in order to properly raise and activate the catalyst device 3 and to operate the internal combustion engine 1 stably. It defines the amount.

Therefore, under the above ideal conditions,
When the bypass opening is operated according to the standard opening command value θ0, the intake air amount for each control cycle of the combustion chamber 4 of the internal combustion engine 1 is calculated as the target intake air amount gair / cmd for each control cycle.
And the integrated value of the target intake air amount gair / cmd may be set as the target integrated intake air amount qair / cmd.

In this case, the target intake air amount gair / cmd and the target integrated intake air amount qair / cmd can be obtained from the standard opening command value θ0 for each control cycle as follows.

First, assuming that the actual bypass opening is θ, the air amount Gi per unit time (fixed time) passing through the bypass valve 7 is equal to the atmospheric pressure Pa, which is the pressure on the upstream side of the bypass valve 7, and the downstream pressure. It is generally expressed by the following equation (3) using the intake pressure Pb which is the side pressure.

[0113]

(Equation 3)

Here, Ci in the equation (3) is a coefficient corresponding to the air density, and the air density corresponds to the atmospheric temperature Ta. The term θ in the equation (3) is strictly the effective opening area at the location of the bypass valve 7, but here, the bypass opening θ is used instead of the effective opening area. Note that the correction of the effect of using the bypass opening degree θ instead of the effective opening area may be included in the coefficient Ci.

In this case, when the bypass opening is operated in accordance with the standard opening command value θ0 under the ideal conditions described above, in equation (3), θ = θ0, Pa = standard atmospheric pressure (constant)
And the coefficient Ci is basically a constant value corresponding to the standard atmospheric temperature. Further, in the steady operating state of the internal combustion engine 1 in the FIRE mode, the change in the intake pressure Pb is relatively small and substantially constant. Further, in a steady operation state of the internal combustion engine 1 in the FIRE mode, the throttle valve 5 is basically in a closed state, and the intake air amount of the combustion chamber 4 of the internal combustion engine 1 is reduced by the air passing through the bypass valve 7. It can be considered equal to the quantity Gi.

Therefore, under ideal conditions, when the bypass opening is operated in accordance with the standard opening command value θ0, the intake air amount per unit time (constant time) of the combustion chamber 4 is equal to the standard opening command value θ0. Proportional.

Therefore, under ideal conditions, when the bypass opening is operated according to the standard opening command value θ0, the intake air amount per control cycle (1 TDC) of the combustion chamber 4, that is, the target intake air amount gair / cmd can be obtained by the following equation (4).

[0118]

(Equation 4)

Here, the term of the reciprocal (1 / Ne) of the rotational speed Ne of the internal combustion engine 1 is included in the equation (4) because the time of one control cycle (1 TDC) in the present embodiment is equal to the rotational speed Ne. Because it is inversely proportional to As is clear from the above, the parameter Ga2 in the equation (4) is, for example, the standard atmospheric pressure and the standard atmospheric temperature, the standard intake pressure Pb in the steady operation state of the internal combustion engine 1 in the FIRE mode, and the like. Is a predetermined constant determined by

In the present embodiment, the target intake air amount gair / cmd obtained by the equation (4) is cumulatively added for each control cycle by the following equation (5) during the operation of the FIRE mode. The target integrated intake air amount qair / cmd is obtained.

[0121]

(Equation 5)

Since the target integrated intake air amount qair / cmd obtained in this manner is determined by the standard opening command value θ0, the engine temperature Tw at the start of the internal combustion engine 1 is determined.
(Or the initial temperature of the catalyst device 3). Further, corresponding to the target cumulative intake air amount qair / cmd,
The intake air amount for each control cycle to be taken into the combustion chamber 4 of the internal combustion engine 1, that is, the target intake air amount gair / cmd
Changes in accordance with the FIRE elapsed time t / fire in the form of a temporal change similar to the standard opening command value θ0.

The target integrated intake air amount qa as described above
ir / cmd is set in advance by a time table, and FI is used for each control cycle using this time table.
It may be obtained from the RE elapsed time t / fire.

In the system of this embodiment, the intake air amount F
The / B control correction process is basically performed by calculating the estimated integrated intake air amount qair / pre (which corresponds to the integrated value of the amount of heat actually given to the catalyst device 3) as described above. Feedback control processing to converge to the amount qair / cmd (this corresponds to the target value of the integrated value of the amount of heat to be given to the catalyst device 3) (by eliminating these deviations) The correction amount is obtained, and the standard opening command value θ0 is corrected by the correction amount to determine the bypass opening command value, thereby compensating for the variation in the intake air amount due to the above-described structural factors. This is to eliminate the variation in the temperature rising mode.

In this case, in the intake air amount F / B control correction processing, as described later, the decay speed of the difference between the estimated integrated intake air amount qair / pre and the target integrated intake air amount qair / cmd (estimated integrated intake air amount qair) It is preferable to variably set the convergence speed of / pre to the target integrated intake air amount qair / cmd) depending on the situation. (More specifically, adaptive sliding mode control) is used in the above-described feedback control processing.

Using this adaptive sliding mode control (hereinafter referred to as intake side adaptive SLD control), the command value of the bypass opening is set so that the estimated integrated intake air amount qair / pre converges to the target integrated intake air amount qair / cmd. In the present embodiment, the algorithm of the intake air amount F / B control correction process for correcting the following is constructed as follows. In the following description, for convenience of explanation, the estimated integrated intake air amount qa will be briefly described.
The integrated intake air amount Qa is calculated by using the reference value Qa as an integrated value of the actual intake air amount of the combustion chamber 4 of the internal combustion engine 1 including ir / pre.
The target value is referred to as a target integration amount q using a reference symbol q.
(This corresponds to the target integrated intake air amount qair / cmd). In addition, the command value of the bypass opening is generally referred to as an opening command Θ using a reference symbol Θ.

First, the actual intake air amount of the combustion chamber 4 of the internal combustion engine 1 for each control cycle is represented by reference symbol Gcyl, and the correlation between the intake air amount Gcyl and the opening command Θ is given by the following equation. As shown in (6), it is represented by a discrete system (discrete time system) model of a first-order lag system (first-order autoregressive model).

[0128]

(Equation 6)

Here, α and β in the equation (6) represent the atmospheric pressure P
These are model parameters corresponding to a, the atmospheric temperature Ta, the intake pressure Pb, the rotation speed Ne, and the like.

Since the integrated intake air amount Qa for each control cycle is expressed by the following equation (7),

[0131]

(Equation 7)

The following equation (8) is obtained using the equations (7) and (6).

[0133]

(Equation 8)

Here, Gcyl (k) in the equation (8) is Gcyl (k) = Qa (k) -Qa (k-1) according to the equation (7). And rearranging by the following equation (9)
Is obtained.

[0135]

(Equation 9)

Equation (9) indicates that the system for generating the integrated intake air amount Qa from the opening degree command 、 in the system of the present embodiment, that is, the system to be controlled by the intake side adaptive SLD control is a discrete system. (A quadratic autoregressive model; hereinafter, referred to as an intake control target model). That is, the intake control target model calculates the integrated intake air amount Qa (k + 1) in each control cycle as the output of the control target of the intake side adaptive SLD control, and calculates the integrated intake air amount Qa in the past control cycle. This is expressed using the time series data Qa (k) and Qa (k-1) and the opening command Θ (k) as an input of a control target of the intake-side adaptive SLD control. In equation (9), the integrated intake air amount Qa
The coefficients a1 and a2 relating to (k) and Qa (k-1) and the coefficient b1 relating to the opening command Θ (k) are model parameters that define the behavior characteristics of the intake control target model.

In the present embodiment, the algorithm of the intake side adaptive SLD control is constructed as follows based on the intake control target model.

That is, in the intake-side adaptive SLD control, the switching function σ1 required for the sliding mode control is calculated by calculating the difference Eq between the integrated intake air amount Qa and the target integrated amount q =
Time series data Eq (k), Eq for each control cycle of Qa-q
It is defined by a linear function of the following equation (10) using (k-1) as a variable.

[0139]

(Equation 10)

Here, s 1 and s 2 in the equation (10) are coefficient parameters of each term of the switching function σ 1, and the following equation (11)
Is set to satisfy the condition of

[0141]

[Equation 11]

In this embodiment, s1 is used for simplification.
= 1. Further, in the present embodiment, the value of the coefficient parameter s2 (more generally, the value of s2 / s1) is variably set, which will be described later.

When the switching function σ1 is defined as described above,
As shown in FIG. 8, a state quantity (Eq (k), Eq (k-1)) composed of a set of the time series data Eq (k) and Eq (k-1) of the deviation Eq is expressed as σ
By converging on a switching line (which is also called a slip line) defined by a relational expression of 1 = 0 and maintaining the convergence state, the state quantities (Eq (k), Eq (k-1)) are The equilibrium point on the switching line σ1 = 0 extremely stably without the influence of disturbances,
That is, it is possible to converge to a point where Eq (k) = Eq (k-1) = 0.

In this embodiment, since the phase space related to the switching function σ1 is two-dimensional (the state quantities (Eq (k), Eq
The component (k-1)) is two) and the switching line σ 1 = 0 is a straight line, but when the phase space is three-dimensional, the switching line is a plane, and in this case, the switching line is It is sometimes called a slip surface. Furthermore, when the phase space becomes higher than four dimensions, the switching line becomes a hyperplane which cannot be shown geometrically.

On the other hand, in order to make the integrated intake air amount Qa converge to the target integrated amount q, the intake side adaptation S
The control input generated by the LD control, that is, the opening command Θ,
Basically, an equivalent control input Θeq determined based on a control law for constraining the state quantities (Eq (k), Eq (k-1)) to the switching line σ1 = 0 determined as described above, Quantity (Eq (k), E
q (k-1)) and a state law (Eq (k), Eq (k-1)), which is based on a reaching law input Θrch determined based on a reaching law that is a control law for converging the switching line σ1 = 0. This is the sum of an adaptive law input Θadp determined based on an adaptive law which is a control law for eliminating the influence of disturbance or the like upon convergence to the switching line σ1 = 0 (see the following equation (12)).

[0146]

(Equation 12)

In the ordinary sliding mode control, the adaptive law is not considered, and in this case, the adaptive law input Θad
p is omitted.

In this case, the equivalent control input Θeq is given by the following equation (1)
Given by 3).

[0149]

(Equation 13)

Note that this equation (13) is equivalent to the state quantity (Eq (k),
Σ1 (k) = for constraining Eq (k-1)) to the switching line σ1 = 0
It can be derived based on the condition of σ1 (k-1) and the equation (9) of the intake control object model.

Further, reaching law input {rch and adaptive law input}
The adp can be determined by various methods. However, in this embodiment, the reaching law input Θrch and the adaptive law input Θadp
Is the value of the switching function σ 1 and the switching function σ
It is made to be proportional to the integrated value (integrated value) of the value of 1 and is determined by the following equations (14) and (15), respectively.

[0152]

[Equation 14]

[0153]

(Equation 15)

Here, F1 in the equation (14) is a coefficient defining the gain relating to the attainment law, and may be set so as to satisfy the condition of the following equation (16). However, the switching function σ1
In order to reduce the chattering at the time of the convergence of the value to the switching line .sigma.1 = 0, it is preferable to set the coefficient F1 so as to satisfy the condition of Expression (16) '.

[0155]

(Equation 16)

F2 in the equation (15) is a coefficient defining the gain relating to the adaptive law, and may be set so as to satisfy the condition of the following equation (17). Note that Δ in equation (17)
T is a control cycle (control cycle).

[0157]

[Equation 17]

In the algorithm of the intake-side adaptive SLD control used in the present embodiment, basically, the equations (13) to (1)
5) The equivalent control input Θeq, the reaching law input Θrch, and the adaptation law input Θadp are obtained according to 5), and the sum thereof is generated as the opening degree command よ う so that the integrated intake air amount Qa converges on the target integrated amount q. It is possible to operate the intake air amount during the operation in the FIRE mode.

By the way, the equivalent control input Θeq, the reaching law input Θrch, and the adaptive law input adp are respectively expressed by the above-mentioned equation (13).
(15), the model parameters a1, a of the intake control object model represented by the above equation (9)
It is necessary to identify the values of 2, b1. However, the values of these model parameters a1, a2, b1 are FI
Under the influence of various factors during the operation of the RE mode, it is likely to be troublesome to perform the optimum identification of those values.

Therefore, in the present embodiment, a simplified algorithm of the intake-side adaptive SLD control is constructed by eliminating the model parameters a1, a2, and b1 as follows.

First, reaching law input {rch and adaptive law input}
Regarding adp, the above equation (1)
The model parameters included in 4) and (15) are only b1. Then, if (F1 / b1) is replaced by Fx in equation (14), and (F2 / b1) is replaced by Fy in equation (15), equations (14) and (15) are respectively expressed by the following equations ( 18) and (19).

[0162]

(Equation 18)

[0163]

[Equation 19]

Therefore, according to these equations (18) and (19), the reaching law input Θ can be obtained without using the model parameter b1.
rch and the adaptive law input Θadp can be obtained.

In this case, the values of the coefficients Fx and Fy in the equations (18) and (19) correspond to the switching line σ1 of the value of the switching function σ1.
It may be determined through experiments and simulations in consideration of the stability and quick response of convergence to = 0.

Next, with respect to the equivalent control input Θeq, the equation (13) for obtaining the equivalent control input Θeq is obtained by calculating the deviation Eq = Qa
The following equation (20) can be rewritten using -q.

[0167]

(Equation 20)

The term including the first bracket in the equation (20) is a deviation E between the integrated intake air amount Qa and the target integrated amount q.
In the feedback term based on q, the term including the second bracket is a feedforward term based only on the target integration amount q. Hereinafter, the feedback term and the feedforward term are set as Θeq / fb and Θeq / ff as shown in the following equations (21) and (22), respectively.

[0169]

(Equation 21)

[0170]

(Equation 22)

Here, the feedforward term Θeq / f
f is an input (opening command Θ) to be given to the control target in a state where the deviation Eq is constantly “0”. On the other hand, in the present embodiment, the standard opening command value θ0 defines the target integrated amount q, and the intake air amount, and consequently, the integrated intake air amount with respect to the standard opening command value θ0, is the target. This is set in a feed-forward manner as being uniquely determined to be a value to be performed.

Therefore, the feedforward term Θeq / ff in the equation (20) can be replaced with the standard opening command value θ0 that does not include the model parameters a1, a2 and b1.

Further, with respect to the feedback term Θeq / fb, the equivalent control input 含 む eq including the feedback term Θeq / fb changes the state quantity (Eq (k), Eq (k-1)) to the switching line σ1 = It is a control input to constrain on 0,
According to various studies by the inventors of the present application, in the system of the present embodiment, the state quantities (Eq (k), Eq (k-1)) have the switching line σ1 = 0.
Is high in the state in the vicinity of. In the present embodiment, by adopting the adaptive law input Θadp,
The stability of the convergence of the state quantities (Eq (k), Eq (k-1)) on the switching line σ1 = 0 can be improved.

Therefore, in the system of the present embodiment, it is considered that the controllability is not practically impaired even if the feedback term Θeq / fb is omitted.

In consideration of the above, it is considered that the equivalent control input も eq may be such that the feedback term Θeq / fb is omitted and the feedforward term Θeq / ff is replaced with the standard opening command value θ0. In this way, the equivalent control input Θeq is calculated from the model parameters a1 and a2
, B1 can be obtained.

Thus, in the present embodiment, the intake side adaptive SL
The equivalent control input Θeq of the D control is given by the following equation (23).

[0177]

(Equation 23)

As described above, in the intake air amount F / B control correction processing in the present embodiment, the intake side adaptation S
The input to the control object determined by the LD control, that is, the opening command Θ is obtained by the calculation of the following equation (24).

[0179]

(Equation 24)

In other words, in the present embodiment, the reaching law input Θrch obtained by the equations (18) and (19) is used.
And the sum of the adaptive law input Θadp (= Θrch + Θadp) is calculated by the correction amount i / sl of the command value of the bypass opening as in the following equation (25).
d (hereinafter referred to as an SLD opening correction amount i / sld), and the standard opening command value θ0 is corrected by the SLD opening correction amount i / sld (the SLD opening correction amount i / sld is added to the standard opening command value θ0). / sld) to obtain an opening command Θ for compensating for variations due to structural factors.

[0181]

(Equation 25)

In this case, the SLD opening correction amount i / sl
In the present embodiment, the value of the switching function σ1 required to obtain d (= Θrch + Θadp) is, in the present embodiment, the estimated integrated intake air amount qair obtained by the expression (2) as the integrated intake air amount Qa of the expression (10). / pre and the target integrated intake air amount qair obtained by the equation (5) as the target integrated amount q.
It is calculated by the following equation (26) using / cmd.

[0183]

(Equation 26)

In the present embodiment, the calculation of the SLD opening correction amount i / sld is interrupted during the interruption operation of the FIRE mode (when the FIRE interruption flag f / fpause is set to "1"). (The value of the SLD opening correction amount i / sld is kept at the value immediately before the interruption operation.) The estimated integrated intake air amount qair / p
The calculation of re and the target cumulative intake air amount qair / cmd is continued (however, the estimated cumulative intake air amount qair / pre is not
Except during fuel cut). If the suspension operation is released before the FIRE limit time TFIRELMT elapses, the calculation of the SLD opening correction amount i / sld and the correction of the standard opening command value θ0 corresponding thereto are restarted. I do.

This is done for the following reason. In other words, during the interruption operation of the FIRE mode, basically, the vehicle is driven or the internal combustion engine 1 is overrun by operating the accelerator pedal of the vehicle. In this situation, since the throttle valve 5 is opened at an opening corresponding to the accelerator operation amount Ap, the actual intake air amount of the combustion chamber 4 of the internal combustion engine 1 is reduced to the intake air amount via the bypass valve 7. , The amount of air intake via the throttle valve 5 is added.

In such a situation, the estimated integrated intake air amount
Since qair / pre is an integrated value of the intake air amount by both the bypass valve 7 and the throttle valve 5, this is integrated with a target integrated intake air amount qair / cmd determined according to the standard opening command value θ0 of the bypass valve 7. It is not preferable to operate the bypass opening so as to converge on the operation performance of the internal combustion engine 1 in accordance with the operation of the accelerator pedal. For this reason, in this embodiment, during the interruption operation of the FIRE mode, the SLD
The calculation of the opening correction amount i / sld is interrupted.

During the interruption operation of the FIRE mode, the actual intake air amount of the combustion chamber 4 of the internal combustion engine 1 is obtained by adding the intake air amount via the throttle valve 5 to the intake air amount via the bypass valve 7. Therefore, the amount of heat given to the catalyst device 3 further increases. Therefore, the catalyst device 3 may be sufficiently heated and activated during the interruption operation of the FIRE mode, but in many cases, the interruption operation is canceled in a short time. The temperature rise and activation of the device 3 may still be insufficient. For this purpose, in the present embodiment, the calculation of the estimated integrated intake air amount qair / pre and the target integrated intake air amount qair / cmd is continuously performed even during the interruption operation of the FIRE mode, and the SLD is performed after the interruption operation is released. By restarting the calculation of the opening correction amount i / sld and correcting the standard opening command value θ0, the temperature rise and activation of the catalyst device 3 during the operation of the FIRE mode are ensured. However, in this case, regarding the estimated cumulative intake air amount qair / pre, since the air taken into the combustion chamber 4 does not contribute to the amount of heat given to the catalyst device 3 during the fuel cut of the internal combustion engine 1, Is the estimated cumulative intake air amount qair / p
Do not calculate re.

In this embodiment, even when performing the ignition timing responsive correction process described later, the SLD opening correction amount i /
The calculation of sld is interrupted (the value of the SLD opening correction amount i / sld is held at the value immediately before the interruption operation). This is for the following reason. That is, although the details will be described later, the ignition timing responsive correction process is a process for correcting the opening command Θ in a feedforward manner with respect to the standard opening command value θ0 in a decreasing manner, and such processing is performed. At this time, when the SLD opening correction amount i / sld is calculated, the opening command Θ
This is because the SLD opening correction amount i / sld is calculated so as to cancel out the decrease in.

The contents described above are the basic contents of the intake air amount F / B control correction processing.

In the present embodiment, the stage immediately after the start of increasing the intake air amount of the internal combustion engine 1, that is, the stage of increasing the bypass opening, is performed in the internal combustion engine 1
Therefore, if the standard opening command value θ0 is greatly corrected by the SLD opening correction amount i / sld at this stage, the combustion state of the air-fuel mixture in the combustion chamber 4 of the internal combustion engine 1 deteriorates. Or the deterioration of the emission state of the internal combustion engine 1 may be caused. In the present embodiment, the target integrated intake air amount
Since qair / cmd assumes a steady intake state of the internal combustion engine 1, immediately after the start of increasing the intake air amount,
It is considered that the reliability of the target integrated intake air amount qair / cmd is poor. Therefore, immediately after the start of the increase of the intake air amount, the deviation Eq between the target integrated intake air amount qair / cmd and the estimated integrated intake air amount qair / pre becomes large, and the SLD opening correction amount i / sld may also be large.

In consideration of the above, in the intake air amount F / B control correction processing in the present embodiment, after the start of the increase of the intake air amount (after the start of the FIRE mode), a predetermined time TISLDL is set.
MT (SLD correction limit time TISLDLMT; see FIG. 7)
Until Elapses (until FIRE elapsed time t / fire ≧ TISLDLMT), the values of the target integrated intake air amount qair / cmd and the estimated integrated intake air amount qair / pre are forcibly set to “0” ( At this time, Eq = 0). By doing this,
FIRE elapsed time t / fire is SLD correction limit time TISLDLMT
In the state immediately after the start of the internal combustion engine 1 until the pressure reaches
The value of the D opening correction amount i / sld is also maintained at "0" so that the standard opening command value θ0 is not corrected by the SLD opening correction amount i / sld.

Furthermore, the intake air amount F / B in the present embodiment
In the control correction process, even immediately after the actual correction of the standard opening command value θ0 by the SLD opening correction amount i / sld is started, if the correction is rapidly performed, the combustion state and the emission performance of the internal combustion engine 1 are impaired. There is a fear. For this reason, in the present embodiment, the estimated integrated intake air amount qair / pre and the target integrated intake air amount qair / cmd are utilized by utilizing the response designation characteristic of the intake-side adaptive SLD control used in the intake air amount F / B control correction process. (The estimated cumulative intake air amount qair / pre and the target cumulative intake air amount qair / c of the deviation Eq)
convergence speed to md) is variably set as follows.

That is, in the intake-side adaptive SLD control, the state quantities (Eq (k), Eq (k-1)) related to the intake deviation Eq
Is converged to the switching line σ 1 = 0, the above equation (1)
As is clear from 0), the following relational expression (27) holds.

[0194]

[Equation 27]

Therefore, the coefficient parameter s of the switching function σ 1
1, s2 ratio (s2 / s1) (however, -1 <s2 / s1)
The value of <1) defines the rate of decay of the intake deviation Eq to "0" (the closer the | s2 / s1 |
The decay rate is faster). Therefore, this ratio (s2 / s1)
, The attenuation speed of the intake deviation Eq can be designated, which is the response designation characteristic of the intake-side adaptive SLD control.

It should be noted that increasing the decay speed of the intake deviation Eq is equivalent to increasing the gain of the feedback control by the intake-side adaptive SLD control.
Equation (27) expresses a first-order lag system with no input, and the ratio (s2 / s1) corresponds to the pole of the first-order lag system (hereinafter, the ratio (s2 / s1) ) Is called pole pole / i). In this embodiment, s1 =
It is set to 1, in this case, pole / i = s2. Further, the attenuation of the intake air deviation Eq to “0” is preferably non-vibrating. Therefore, in the present embodiment, s2 / s
1 = pole / i <0 (s2 / s1> 0,
As is apparent from the equation (27), the attenuation of the intake air deviation Eq to “0” becomes oscillatory.)

In the intake air amount F / B control correction processing in this embodiment, the response designation characteristic of the intake side adaptive SLD control is used, and basically, the FIRE elapsed time t / fire is shown in FIG. By setting a value pole / itbl (hereinafter referred to as a pole table value pole / itbl) obtained for each control cycle based on a predetermined data table (time table) as the value of the pole pole / i, The value of pole / i is variably set according to the FIRE elapsed time t / fire.

Here, in the data table of FIG.
RE elapsed time t / fire is a predetermined value TPOLEVST (however, TPOLEVST
≧ SLD correction time limit TISLDLMT), and then the pole table value pole / itbl and, consequently, the pole pole / i are FIR
As the elapsed time t / fire increases, the specified lower limit pole / i0
(<0; “−1” in this embodiment) from a predetermined steady-state value po
le / ix (pole / i0 <pole / ix <0), gradually increase (the absolute value of the pole table value pole / itbl is gradually reduced), and after the steady value pole / ix is reached ( FIR
E After the elapsed time t / fire reaches the predetermined value TPOLEX in FIG. 9)
Is maintained at the steady value pole / ix. As a result, in this embodiment, immediately after the correction of the standard opening command value θ0 by the SLD opening correction i / sld is started, the decay speed of the intake deviation Eq is gradually increased (the estimated integrated intake air amount qair). / pre gradually increases to the target integrated intake air amount qair / cmd), and the predetermined value TPOL is maintained until the FIRE elapsed time t / fire reaches the predetermined value TPOLEX.
The rate of decay of the intake deviation Eq is set to be slower than after reaching EX.

The above-described increase of the pole pole / i by the pole table value pole / itbl is basically performed at an initial stage after the start of the internal combustion engine 1 (a stage of increasing the intake air amount). .

In this embodiment, during the interruption operation of the FIRE mode, the intake air amount F / B control correction processing (more precisely, the calculation processing of the SLD opening correction amount i / sld) is not performed. In this state, the pole pole / i is set to the lower limit pole / i0 of the pole table value pole / itbl. Then, when the interruption operation of the FIRE mode is released, the pole pole / i is gradually returned from the lower limit value pole / i0 toward the pole table value pole / itbl (see the virtual line in FIG. 9). I have.

Next, the atmospheric condition correction processing for compensating for the influence of the variation in the intake air amount due to the atmospheric conditions described above will be described.

First, the atmospheric pressure among the atmospheric conditions will be described. In this description, it is assumed that the atmospheric temperature is constant and the bypass opening is equal to the opening command Θ.

The pressure in the combustion chamber 4 of the internal combustion engine 1 is set to Pcyl,
Assuming that the opening (effective opening area) of the intake valve 11 (see FIG. 2) is Acyl, the intake air amount Gcyl of the combustion chamber 4 is obtained by using the pressure Pcyl, the opening Acyl, and the intake pressure Pb. Generally, it is expressed by the following equation (28).

[0204]

[Equation 28]

Here, Ci is a coefficient corresponding to the air density, as described with respect to the equation (3).

In this case, in the internal combustion engine 1, the pressure in the combustion chamber 4 in the equation (28) is Pcyl, and the opening Acyl of the intake valve 11 is basically constant. Also, the coefficient Ci may be considered constant if the atmospheric temperature Ta is constant.

Accordingly, from the equation (28), in order to make the intake air amount Gcyl in the combustion chamber 4 independent of the atmospheric pressure, it is necessary that the intake pressure Pb does not change according to the atmospheric pressure Pa. You can see that.

On the other hand, the air amount Gi passing through the bypass valve 7 with respect to the opening command Θ of the bypass opening is expressed by the following equation (29), as in the above equation (3).

[0209]

(Equation 29)

Further, in a state where the atmospheric pressure Pa is a predetermined standard atmospheric pressure (hereinafter referred to as a reference symbol Pa0), the opening command Θ is changed to the standard opening command value θ0 (this is the standard If the air amount passing through the bypass valve 7 is Gi0 (which corresponds to the target intake air amount gair / cmd) when the atmospheric pressure Pa0 is assumed, the air amount Gi0 (hereinafter referred to as Gi0) , The standard air amount Gi0)
It is expressed by the following equation (30).

[0211]

[Equation 30]

Here, Pb0 in the equation (30) is the intake pressure (hereinafter referred to as the pressure generated in the chamber 13 (see FIG. 2) when the bypass opening is set to the standard opening command value θ0 at the standard atmospheric pressure Pa0. , Standard intake pressure Pb0).

According to the well-known gas equation of state,
The conditions that the intake pressure Pb in the chamber 13 does not fluctuate are the amount of air flowing into the chamber 13, ie, the amount of air Gi passing through the bypass valve 7, and the amount of air flowing out of the chamber 13, ie, the intake air of the combustion chamber 4. And the quantity Gcyl is equal.

From the above, when the atmospheric pressure Pa fluctuates with respect to the standard atmospheric pressure Pa0, the intake air amount Gcy of the combustion chamber 4
The opening command Θ for preventing l from changing is given by equation (2)
9) is determined so that the intake pressure Pb in FIG. 9 becomes equal to the standard intake pressure Pb0, and the air amount Gi expressed by the equation (29) becomes equal to the standard air amount Gi0 (equation (30)). I just need.

That is, the opening command Θ is given by the following equation (3)
What is necessary is just to determine so that the condition of 1) may be satisfied.

[0216]

(Equation 31)

Then, when this equation (31) is solved for the opening command Θ, the following equation (32) is obtained.

[0218]

(Equation 32)

Therefore, basically, if the opening command Θ is determined by correcting the standard opening command value θ0 based on the equation (32), it is possible to compensate for the variation in the intake air amount due to the atmospheric pressure. Can be. That is, the value of the square root kp in the equation (32)
By multiplying the opening command by a (hereinafter referred to as an atmospheric pressure correction coefficient kpa) and correcting the opening command, it is possible to determine the opening command for compensating the variation in the intake air amount due to the atmospheric pressure.

In the present embodiment, since the standard opening command value θ0 is changed over time as described above, the equation (3)
The standard intake pressure Pb0 used in the calculation in 2) also changes. Therefore, in order to accurately compensate for the variation in the intake air amount due to the atmospheric pressure, the value of the standard intake pressure Pb0 is set to a standard value using a data table or the like that is determined in advance. It is considered preferable to appropriately change the opening degree in accordance with the opening command value θ0. However, in the present embodiment, during steady operation of the internal combustion engine 1 in the FIRE mode, the fact that the fluctuation of the intake pressure Pb is actually small and the stability of the control system are taken into consideration. Predetermined value (fixed value) predetermined as standard intake pressure Pb0
Is used.

In the present embodiment, in order to reduce the calculation load on the controller 2, the following processing is actually performed without directly performing the calculation of the equation (32).

That is, for each control cycle, a predetermined standard atmospheric pressure Pa0, a standard intake pressure Pb0, and the atmospheric pressure sensor 1 at the time of starting the internal combustion engine 1 (start mode).
The parameter ratio / dpa defined by the following equation (33) from the atmospheric pressure Pa detected by Eq. 8 (hereinafter referred to as an atmospheric pressure correction parameter ratio / dpa), that is, equation (32)
Find the value within the square root of (√).

[0223]

[Equation 33]

A data table shown in FIG. 10 is prepared in advance by calculating the square root for various values of the atmospheric pressure correction parameter ratio / dpa, and the previously determined atmospheric pressure correction parameter ratio The square root of / dpa is obtained as the atmospheric pressure correction coefficient kpa. Then, the opening command is corrected (multiplication correction) using the atmospheric pressure correction coefficient kpa.

Note that the atmospheric pressure correction coefficient kpa is obtained by comparing the atmospheric pressure Pa detected by the atmospheric pressure sensor 18 with the standard atmospheric pressure Pa0.
, The value is “1”, and the value decreases as the atmospheric pressure Pa increases.

The contents described above are the basic contents of the processing for compensating the variation in the intake air amount due to the atmospheric pressure in the atmospheric condition correction processing.

Next, the atmospheric temperature among the atmospheric conditions will be described. As is apparent from equation (28), the intake air amount Gcyl of the combustion chamber 4 of the internal combustion engine 1 is affected by the coefficient Ci according to the atmospheric density, and increases as the atmospheric density increases.
The air density becomes lower as the air temperature is higher. Therefore, the intake air amount Gcyl of the combustion chamber 4 becomes higher as the air temperature becomes higher.
Less.

Therefore, even if the atmospheric temperature changes, the combustion chamber 4
In order to prevent the intake air amount Gcyl from changing, the opening command Θ may be corrected so that the bypass opening increases as the atmospheric temperature increases.

Therefore, in the present embodiment, at the time of starting the internal combustion engine 1 (start mode), a data table determined in advance based on experiments and the like as shown in FIG. Correction coefficient kta (hereinafter referred to as atmospheric temperature correction coefficient kta)
And the opening command is corrected (multiplied) using the atmospheric temperature correction coefficient kta.

In this case, in the present embodiment, since the intake air amount at the standard atmospheric temperature Ta0 (for example, 25 ° C.) is used as a reference, the atmospheric temperature correction coefficient kta is determined by comparing the detected atmospheric temperature Ta with the standard atmospheric temperature Ta0. Sometimes it is "1",
The value increases as the atmospheric temperature Ta increases.

This is the reason for the above-mentioned atmospheric condition correction processing.
This is the basic contents of processing for compensating for variations in the amount of intake air due to atmospheric temperature.

Next, the learning correction processing will be described.

In this embodiment, as described above, in order to compensate for variations in the intake air amount due to the structural factors, the intake air amount F / B control correction processing using the intake side adaptive SLD control is performed for each control cycle. SLD opening correction i / sl
d is obtained, and the standard opening command value θ0 is corrected by the SLD opening correction amount i / sld. In this case, the actual intake air amount with respect to the standard opening command value θ0 differs from the original standard intake air amount corresponding to the standard opening command value θ0 due to aging of the bypass valve 7 and the like. When the target intake amount Qa (estimated integral intake air amount qair / pre) is not converged with the target integral amount q (target integral intake air amount qair / cmd) in a state in which The SLD opening correction amount i / sld is large, and its temporal change is also large. Therefore, the SLD opening correction amount
The opening command Θ determined by correcting the standard opening command value θ0 by i / sld, and thus the pattern of the temporal change of the actual intake air amount, is the time of the standard opening command value θ0 in the initial stage of the FIRE mode. In some cases, a temporal change greatly deviates from a pattern of a temporal change (a pattern of a temporal change of a target intake air amount).

However, especially in the initial stage of the FIRE mode (a state shortly after the start of the internal combustion engine 1), the combustion chamber 4
The combustion state of the air-fuel mixture at the time tends to be unstable, and the pattern of the temporal change of the opening command Θ is the standard opening command value θ0.
If the change greatly deviates from the temporal change pattern, there is a possibility that the combustion state and the emission state may be deteriorated.

Therefore, in the learning correction process of this embodiment, the value to be obtained for each control cycle is learned during the operation of the FIRE mode, and the standard opening command value θ0 is multiplied and corrected over the entire period of the next operation of the FIRE mode. Correction coefficient kilearn (hereinafter referred to as learning correction coefficient kilearn) is obtained. Then, by multiplying the learning correction coefficient kilearn by the standard opening command value θ0, an opening command Θ exhibiting a stable temporal change consistent with the temporal change pattern of the standard opening command value θ0 is generated.

In this case, the learning correction coefficient kilearn is determined as follows in this embodiment.

That is, the SLD opening correction amount i / sld obtained for each control cycle during each operation of the FIRE mode.
From the following equation (34), the SLD opening correction amount i / sl
A correction amount gair / sld of the actual intake air amount corresponding to d (hereinafter referred to as an SLD intake correction amount gair / sld) is obtained for each control cycle.

[0238]

(Equation 34)

Here, equation (34) is obtained by equation (4) for obtaining the target intake air amount gair / cmd, that is, the actual intake air amount (per TDC) corresponding to the standard opening command value θ0. It is a similar formula, and Ga2 in the formula (34) is the same as Ga2 in the formula (4).

Further, the SLD intake correction amount gair / sld is cumulatively added for each control cycle according to the following equation (35), so that the integrated value qair / sld of the SLD intake correction amount gair / sld (hereinafter referred to as SLD integrated intake correction). Qair / sld).

[0241]

(Equation 35)

The SLD integrated intake air correction amount qair / s
The ratio (qair) of ld to the target integrated intake air amount qair / cmd
/ sld / qair / cmd) is used to determine a basic value vpskisld of the learning correction coefficient kilearn (hereinafter referred to as a basic learning correction coefficient vpskisld).

[0243]

[Equation 36]

The basic learning correction coefficient vpskisld is basically calculated for each control cycle until the operation of the FIRE mode is completed. When the response correction process is performed, the SLD opening correction amount i /
Since the calculation of sld is interrupted, the basic learning correction coefficient vpskisld before the interruption operation of the FIRE mode or the ignition timing responsive correction process is started (before the learning calculation end flag f / flrnend is set to “1”). Is completed.

The basic learning correction coefficient vp finally obtained during each operation of the FIRE mode in this manner
A learning correction coefficient kilearn for correcting the standard opening command value θ0 at the time of the next operation of the FIRE mode is obtained by performing a smoothing operation process (filtering process) according to the following equation (37) on skisld.

[0246]

(37)

Here, kilearn (j) in the equation (37) means a learning correction coefficient kilearn newly determined by the current operation of the FIRE mode, and kilearn (j-1) is the previous FILE mode.
The learning correction coefficient ki determined by the operation in the IRE mode
Means learn. Cki in the equation (37) is a predetermined constant of “1” or less.

In this case, in each operation of the FIRE mode, the final basic learning correction coefficient vpskis
FIRE elapsed time t / fire when ld was determined (this is
STEPs 5-5 and 5-16 in the flowchart of FIG.
Is less than the predetermined time, the basic learning correction coefficient vpskisld
Is not used for obtaining (updating) the learning correction coefficient kilearn, and maintains the current value of the learning correction coefficient kilearn. This is because the reliability of the basic learning correction coefficient vpskisld obtained at a stage where the FIRE elapsed time t / fire is short is poor.

The processing described above is the basic content of the learning correction processing.

Next, the ignition timing responsive correction processing will be described.

In this embodiment, as described above, when the internal combustion engine 1 warms up to some extent (FIRE elapsed time t / fi).
When re increases to some extent), the tendency of the rotation speed Ne of the internal combustion engine 1 to increase due to a decrease in the friction of each part of the internal combustion engine 1 is suppressed, and the ignition timing becomes the ignition timing operation rotation speed F / B.
In order to prevent the operation from being excessively retarded by the control, the standard opening command value θ0 is gradually reduced (see FIG. 7).

However, the form of the decrease in friction accompanying the warm-up of the internal combustion engine 1 is affected by various factors, and the decrease in the friction starts earlier than expected, or the decrease in the friction decreases. The degree may be larger than expected.

In such a case, even if the standard opening command value θ0 is gently reduced as described above,
The tendency of the rotational speed Ne of the internal combustion engine 1 to increase cannot be sufficiently suppressed. As a result, the ignition timing operation speed F / B
The ignition timing operated by the control reaches the limit value on the retard side that can be actually operated, and the rotation speed N
e cannot be feedback-controlled to the target rotational speed ne / fire.

The ignition timing responsive correction process is a process performed to avoid such a situation. The ignition timing command value determined by the ignition timing operation rotational speed F / B control as described later is changed to the retard side. When the retarded value exceeds the predetermined threshold value slightly set on the advance side of the limit value of the limit value until the condition is resolved (the ignition timing command value is equal to or more than the threshold value on the advanced side). Until the value returns to the value, the standard opening command value θ0 is corrected by a predetermined amount toward the decreasing side in each control cycle.

That is, for example, with the bypass opening being operated in accordance with the standard opening command value θ0 as shown in the upper part of FIG. 12, the ignition timing operation rotational speed F / is determined as shown in the A12 region in the lower part of FIG. When the command value iglog of the ignition timing determined by the B control falls to the retard side from the threshold value IGX which is slightly larger than the limit value IGLGG on the retard side, the opening command Θ is changed with respect to the standard opening command value θ0. As shown in the upper part of FIG. 12, a certain correction amount θdec (hereinafter referred to as an ignition timing responsive opening correction amount θdec) is reduced (減少 = θ0−θdec).

In this case, the ignition timing responsive opening correction amount θdec
As shown in the B12 region in the upper part of FIG. 12, the ignition timing command value iglog returns to the advance side which is equal to or larger than the threshold value IGX.
It is increased by a predetermined amount Δθdec (> 0, hereinafter referred to as an opening reduction unit amount Δθdec) for each control cycle (see the equation in STEP15-9 in FIG. 15).

After the ignition timing command value iglog has returned to the advance side which is equal to or greater than the threshold value IGX as shown in the lower part C12 of FIG. 12, the ignition timing is responsive as shown in the upper part D12 of FIG. The opening correction amount θdec is held at the value at the time of the return (the process of increasing the ignition timing response opening correction amount θdec by the opening reduction unit amount Δθdec is stopped), and the held ignition timing response opening correction amount The opening command Θ is corrected by θdec to a value smaller than the standard opening command value θ0.

In this embodiment, the opening decrease unit amount Δθdec for increasing the ignition timing responsive opening correction amount θdec for each control cycle is shown in FIG. 13 from the engine temperature Tw at the time of starting the internal combustion engine 1. It is determined based on a data table determined in advance as described above. In this case, particularly when the engine temperature Tw at the time of starting the internal combustion engine 1 is in a high temperature range,
In the data table of FIG. 13, the opening degree reduction unit amount Δθdec in the high temperature region of the engine temperature Tw is larger than that in the low / medium temperature region because the friction is more likely to decrease than in the case where the engine temperature Tw is in the low / medium temperature region. Is set to

The contents described above are the basic contents of the ignition timing responsive correction processing.

Based on the above description, the process of generating the command value (opening command) θCMD of the bypass opening performed by the intake air amount control stage 25 in STEP 4-5 of FIG. 4 will be specifically described below. I do.

Referring to the flowchart of FIG. 14, in STEP4-5, the FIRE execution enable / disable flag f / set for each control cycle as described above in the condition determination process of STEP4-4 (see FIG. 15). Determine the value of fireon (the value set in the current control cycle) (STEP
14-1).

At this time, when f / fireon = 1, that is, when the operation mode is set to the FIRE mode, the standard opening command value θ0 used for obtaining the standard opening command value θ0 by the standard opening command value generation processing is used. N range basic value if
iret and D range correction value iatfire, the atmospheric pressure correction coefficient kpa and the atmospheric temperature correction coefficient kta used in the atmospheric condition correction processing, and the opening degree reduction unit amount Δθdec used in the ignition timing response correction processing, respectively. Correspondingly, using the data table determined as described above (STEP 1)
4-2).

That is, the starting mode process (STEP
Engine temperature Tw at the start of the internal combustion engine 1 obtained in 4-2)
Then, the N range basic value ifiret and the D range correction value iatfire are obtained based on the data table of FIG.

Further, from the atmospheric pressure Pa at the start of the internal combustion engine 1 obtained in the start mode process and the predetermined standard atmospheric pressure Pa0 and standard intake pressure Pb0, the above equation (3) is obtained.
According to 3), the atmospheric pressure correction parameter ratio / dpa
Is calculated, and an atmospheric pressure correction coefficient kpa (= square root of the parameter ratio / dpa) is obtained from the parameter ratio / dpa based on the data table of FIG.

Further, an atmospheric temperature correction coefficient kta is obtained from the atmospheric temperature Ta at the time of starting the internal combustion engine 1 obtained in the start mode processing, based on the data table of FIG.

Further, based on the engine temperature Tw at the start of the internal combustion engine 1 obtained in the start mode process, the opening reduction unit amount Δθdec is obtained based on the data table of FIG.

These processes in STEP 14-2 may be performed in advance in the start mode process.

Next, the intake air amount operation means 25 performs the preliminary opening degree command θi / fire by performing the intake amount F / B control correction processing and the ignition timing responsive correction processing on the standard opening degree command value θ0. Is performed as follows (STEP
14-3).

That is, referring to the flowchart of FIG. 15, the present (current control cycle) shift position of the automatic transmission detected by a sensor (not shown) is determined (STEP 15-1). In the case of the range, the basic value i / ftbl of the standard opening command value θ0 is set as the N range basic value ifiret obtained in the STEP 14-2 (STEP 15-2). Also, if the current shift position is D
If it is a range, the N range basic value ifiret
A value obtained by adding the D range correction value iatfire obtained in STEP 14-2 is set as a basic value i / ftbl (STEP 15-3).

Next, the correction coefficient km / fire in the current control cycle is obtained from the current FIRE elapsed time t / fire based on the data table shown in FIG. 7 (STEP).
15-4), the correction coefficient km / fire is calculated in STEP 15-2.
Alternatively, the standard opening command value θ0 is obtained by multiplying the basic value i / ftbl determined in 15-3 (STEP 15-
5). Thus, the standard opening command value θ0 for each control cycle in the FIRE mode is determined.

Next, the intake air amount operating means 25 performs the process of calculating the intake air deviation Eq as shown in the flowchart of FIG. 16 (STEP 15-6).

That is, referring to FIG. 16, first, the current intake pressure Pb detected by the intake pressure sensor 16 and a predetermined value Ga1 are estimated in the current control cycle by the above equation (1). Intake air amount gair / pre
(Estimated value of intake air amount per TDC) is obtained (S
TEP16-1).

Next, it is determined whether or not the fuel cut of the internal combustion engine 1 is being performed (STEP 16-2). If the fuel cut is not being performed, the current FIRE elapsed time t / fire is further reduced by the SLD correction limit time. It is determined whether or not TISLDLMT has been reached (STEP 16-3).

At this time, if t / fire <TISLDLMT, the estimated integrated intake air amount qa in the current control cycle
The value of ir / pre (k) is forcibly set to “0” (STEP 16
-4). If t / fire ≧ TISLDLMT, the estimated cumulative intake air amount qair / pre (k) is obtained by accumulatively adding the estimated intake air amount gair / pre by the equation (2) (STEP 1).
6-5).

When the fuel cut is being performed in STEP 16-2, the air drawn into the combustion chamber of the internal combustion engine 1 at that time does not contribute to the amount of heat given to the catalyst device 3 (during the fuel cut, The combustion of the air-fuel mixture in the first combustion chamber 4 is not performed.
re (k) is held at the current value (STEP 16-6).

The above STEP 16-1 to 16-6
In the FIRE mode (including during the interruption operation), the catalyst device 3 is sequentially switched from the time when the SLD correction limit time TISLDLMT elapses, except when the fuel cut of the internal combustion engine 1 is performed. The estimated integrated intake air amount qair / pre (k) corresponding to the integrated value of the actually applied heat amount is obtained.

Until the SLD correction limit time TISLDLMT has elapsed, that is, immediately after the start of the internal combustion engine 1, the value of the estimated integrated intake air amount qair / pre (k) is forcibly limited to "0". The Rukoto.

Note that the SLD correction time limit TISLDL
In order to limit the value of the estimated cumulative intake air amount qair / pre (k) until MT elapses, for example, the SLD correction limit time TISL
Until the DLMT elapses, the value of the estimated intake air amount gair / pre is forcibly limited to “0”, and the limited estimated intake air amount ga
The calculation of the expression (2) may be performed using the value of ir / pre. Even in this case, the estimated integrated intake air amount qair
The value of / pre (k) is limited to "0" until the SLD correction limit time TISLDLMT has elapsed.

Thus, the estimated integrated intake air amount qair / p
After obtaining re (k), the intake air amount operating means 25 returns to the S
The standard opening command value θ0 obtained by the TEP 15-5, the current rotation speed Ne detected by the rotation speed sensor 14,
From the predetermined value Ga2 determined in advance, the target intake air amount gair / c in the current control cycle is calculated according to the above equation (4).
md (a target value of the amount of intake air per TDC) is determined (STEP 16-7).

Further, the same determination as in STEP 16-3 is performed (STEP 16-8), and at this time, t / fire <TISL
If it is DLMT, the value of the target integrated intake air amount qair / cmd (k) in the current control cycle is forcibly set to “0” (STEP 16-9). If t / fire ≧ TISLDLMT, the target integrated intake air amount gair / pre for each control cycle is cumulatively added according to the equation (5).
qair / cmd (k) is obtained (STEP 16-10).

Steps 16-7 to 16-1 as described above
By the processing of 0, the target integrated intake air amount qair / cmd corresponding to the target value of the integrated value of the amount of heat actually given to the catalyst device 3
(k) shows the SLD correction limit time T after the start of the FIRE mode.
From the time when ISLDLMT has elapsed, it is sequentially obtained, including during the interruption operation of the FIRE mode.

In the state immediately after the start of the internal combustion engine 1 until the SLD correction limit time TISLDLMT has elapsed, the target integrated intake air amount is calculated in the same manner as the estimated integrated intake air amount qair / pre (k).
The value of qair / cmd (k) will be forcibly limited to "0".

The SLD correction time limit TISLDL
In order to limit the value of the target cumulative intake air amount qair / cmd (k) until MT elapses, the value of the target intake air amount gair / cmd is forcibly set until the SLD correction limit time TISLDLMT elapses. 0 ”and the limited target intake air amount gair / cmd
The calculation of the above equation (5) may be performed using the value of.

After obtaining the estimated cumulative intake air amount qair / pre (k) and the target cumulative intake air amount qair / cmd (k) in the current control cycle, the intake air amount operating means 25 Is the difference between them (qair / pre (k) −qair / cmd (k)
) Is calculated to determine the intake air deviation Eq (k) in the current control cycle (STEP 16-11).
The process returns to the process of the flowchart of FIG.

Returning to the description of FIG. 15, after obtaining the intake deviation Eq as described above, the intake air amount operating means 25 next determines the value of the flag f / dec (STEP 15-).
7). The flag f / dec is a flag relating to the ignition timing response correction processing, and is a command value ig of an ignition timing described later.
When the ignition timing command value iglog is a value on the more retarded side than the threshold value IGX (see FIG. 12) in the log generation process, f /
dec = 1, and f / dec = 0 when the command value iglog is an advance value equal to or greater than the threshold value IGX (hereinafter, the flag f / dec is set to an ignition timing determination flag f / dec ). The ignition timing determination flag f / dec is initialized to "0" in the start mode process (STEP 4-2).

At this time, when f / dec = 0 (i.e., when the ignition timing command value iglog is on the advance side which is equal to or greater than the threshold value IGX), the intake air amount operation means 25 sets the intake air amount F / B The processing for calculating the SLD opening correction amount i / sld related to the control correction processing is performed as shown in the flowchart of FIG.
P15-8).

That is, first, the FIRE suspension flag
The current value of f / fpause is determined (STEP 17-1).
At this time, if f / fpause = 1, that is, FIR
In the state where the above-described interruption operation of the E mode is performed,
After setting (initializing) the value of the pole pole / i defining the decay rate of the intake deviation Eq to the predetermined lower limit pole / i0 (see FIG. 9) in the intake air amount F / B control correction processing. (STEP 17-2), and immediately returns to the routine processing of FIG.

Therefore, during the interruption operation of the FIRE mode,
The SLD opening correction amount i / sld is held at the current value (the value before the start of the interruption operation).

The SLD opening correction amount i / sld and the pole po
le / i is initialized to “0” and “lower limit pole / i0” in the start mode process (STEP 4-2), respectively.

On the other hand, according to the judgment in STEP 17-1, f / fpau
When se = 0, that is, when the normal operation in the FIRE mode is performed, the intake air amount operation means 25 determines the current FIRE elapsed time t / fire based on the data table in FIG. To obtain the pole table value pole / itbl in this control cycle (STEP 17).
-3).

Next, basically, the pole table value pole / itbl obtained in STEP 17-3 is set as the value of the pole pole / i which defines the decay speed of the intake deviation Eq. During the lower limit pole
Pole po set to / i0 ("-1" in this embodiment)
le / i is gradually increased after the end of the interruption operation, and the FIRE elapsed time t /
The following processing is performed to return to the pole table value pole / itbl corresponding to fire.

That is, the value of the current pole pole / i pole / i
Unit increment value ΔPOLE / I (> 0) determined in advance for (k-1)
(Pole / i (k-1) + ΔPOLE / I)
It is compared with the pole table value pole / itbl obtained in 7-3 (STEP 17-4). And pole / i (k-1) + ΔPOLE
If / I ≧ pole / itbl, the pole table value pole / itbl obtained in STEP 17-3 is set as the value of the pole pole / i (k) in the current control cycle (STEP 17-3).
17-5) If pole / i (k-1) + ΔPOLE / I <pole / itbl, the value of pole / i (k-1) + ΔPOLE / I is calculated as pole pole / i ( k) (STEP 17-6).

After the interruption operation of the FIRE mode is completed by this processing, the pole pole / i is set to the lower limit pole / i0.
Thus, the unit gradually returns to the pole table value pole / itbl corresponding to the FIRE elapsed time t / fire by the unit increment value ΔPOLE / I.

If the interruption operation of the FIRE mode is not performed immediately after the start of the internal combustion engine 1, the pole pole / i becomes
Basically, the pole table value pole / itbl is set, and the value changes in accordance with the increase in the FIRE elapsed time t / fire in the same form as the pole table value pole / itbl (the unit increment value described above. ΔPOLE / I value is set).

After setting the value of the pole pole / i in this way, the intake air amount operating means 25 further operates the pole po / i.
le / i value and the ignition timing operation speed F described in detail later.
Pole / ig set in the / B control (this is a parameter that defines the decay speed of the deviation between the rotation speed Ne of the internal combustion engine 1 and the target rotation speed ne / fire by the ignition timing operation speed F / B control. ) Is compared with a value obtained by subtracting a predetermined small amount ΔPOLE / IG (> 0) from (ST) (ST
EP 17-7).

Then, at this time, pole / i <pole / ig-Δ
If it is POLE / IG, the process proceeds to the next step 17-9, but if pole / i ≧ pole / ig−ΔPOLE / IG, the value of the pole pole / i is forcibly set (pole / ig−ΔPOLE / IG). ) (STEP 17-8). That is, pole pole / i
Is always smaller than the pole pole / ig (<0) set as described later in the ignition timing operation speed F / B control (more precisely, 1> | pole / i |> | pole / ig ｜
> 0). This is for the following reason.

That is, in this embodiment, the intake-side adaptive SLD control (feedback control) for converging the estimated cumulative intake air amount qair / pre to the target cumulative intake air amount qair / cmd, and the rotational speed Ne of the internal combustion engine 1 The target speed ne / f
Ignition timing operation speed F / B to be converged to ire
While the controls are performed independently of each other, both controls are controls that affect the rotation speed Ne of the internal combustion engine 1. In general, the response of the change in the intake air amount to the change in the bypass opening based on the intake-side adaptive SLD control is the response of the change in the rotation speed Ne to the change in the ignition timing based on the ignition timing operation speed F / B control. Slower than sex.
Therefore, the intake deviation Eq related to the intake side adaptive SLD control is
Is made faster than the decay rate of the difference between the rotation speed Ne of the internal combustion engine 1 and the target rotation speed ne / fire by the ignition timing operation rotation speed F / B control, the two controls interfere with each other. In addition, there is a possibility that the rotation speed Ne of the internal combustion engine 1 becomes unstable.

For this reason, in the present embodiment, the pole pole / i related to the intake side adaptive SLD control is set to | pole
/ i |> | pole / ig | so that
The decay speed of the intake deviation Eq related to the intake side adaptive SLD control is made slower than the decay speed of the deviation between the rotational speed Ne of the internal combustion engine 1 and the target rotational speed ne / fire by the ignition timing operation rotational speed F / B control, Thus, the two controls are prevented from interfering with each other.

Then, in STEP 17-9, Paul po
The value of le / i is compared with “−1”, and if pole / i ≦ −1 (in such a case, it may be caused by the processing of STEP 17-8), the value of pole pole / i Is forcibly set to “−1” (STEP 17-10), and ST
Proceed to EP17-11.

Then, in STEP 17-11, the value of the pole pole / i determined as described above is compared with the value of the above-described STEP.
Based on the intake deviation Eq (k) in the current control cycle and the intake deviation Eq (k-1) in the previous control cycle obtained as described above in 15-6, the above equation (10) (in detail, equation (1)
0) is set to “1” for each of the coefficient parameters s1 and s2,
The value of the switching function .sigma.1 is determined by the equation (replaced by "pole / i").

Further, using the value of this switching function σ1,
The values of the reaching law input Θrch and the adaptive law input Θadp in the intake-side adaptive SLD control are obtained by performing the calculations of the equations (18) and (19) (in this case, s1 = 1) (STE
P17-12), the SLD opening correction amount i / sld in the current control cycle is obtained by adding the reaching law input Θrch and the adaptation law input Θadp (STEP 17-1).
3). Then, the process returns to the routine process of FIG.

Returning to the description of FIG.
If f / dec = 1 in the judgment of -7, that is, if the current ignition timing command value iglog is on the more retarded side than the threshold value IGX (see FIG. 12), the suction The air amount operation means 25 sets the ignition timing responsive opening correction amount θdec to the STE in order to perform the ignition timing responsive correction processing.
It is increased for each control cycle by the opening reduction unit amount Δθdec determined in P14-2 (STEP15-9).

The ignition timing responsive opening correction amount θdec is initialized to “0” in the start mode process (STEP 3-2).

When the processing of STEP 15-9 is performed, the processing for obtaining the SLD opening correction amount i / sld is not performed, and the value of the SLD opening correction amount i / sld is determined by the ignition timing determination flag f. / dec is kept at the value before it was set to "1".

Next, the intake air amount operation means 25 sets the ST
The current SL value is added to the standard opening command value θ0 obtained in EP15-5.
By adding the value of the D-opening correction amount i / sld and further subtracting the current ignition-timing-responsive opening correction amount θdec, the above-described intake-air-amount F / B control correction process and ignition-timing-dependent correction process are performed. Preliminary opening command θi / fire (= θ0 + i / sld −θdec
) Is calculated (STEP 15-10).

Next, the intake air amount operation means 25 judges the current value of the learning calculation end flag f / flrnend (STEP 15-11). This learning calculation end flag f / fl
rnend indicates that the interrupt operation is started (the FIRE interrupt flag f / fpause) while the FIRE mode is operating (the FIRE execution enable / disable flag f / fireon is set to “1”).
Is set to "1"), or when the ignition timing command value iglog is on the more retarded side than the threshold value IGX (see FIG. 12) and the ignition timing responsive correction process is started ( When the ignition timing determination flag f / dec is set to “1”, the value is set to “1” to end the calculation process of the basic learning correction coefficient vpskisld (STEP 5 in FIG. 5).
-17, and STEP22-8 in FIG. 22 described later).

If f / flrnend = 0, that is, if the calculation of the basic learning correction coefficient vpskisld is to be performed, the basic learning correction coefficient vpskisld is calculated as described with respect to the learning correction processing. Yes (STE
P15-12).

That is, in each control cycle, STEP5
The current SLD opening correction amount i / sld obtained in −18;
From the current rotational speed Ne of the internal combustion engine 1 and the predetermined value Ga2, the SLD intake air correction amount gair / s is calculated by the equation (34).
The SLD integrated intake air correction amount qair / sld is obtained by calculating ld and cumulatively adding it by the equation (35). The SLD integrated intake air correction amount qair / sld and the STE
The basic learning correction coefficient vpskisld is calculated by calculating the above equation (36) from the target integrated intake air amount qair / cmd for each control cycle obtained in P16-10 (see FIG. 16).

In this case, the FIRE elapsed time
Until t / fire reaches the SLD correction limit time TISLDLMT, qair / cmd = 0 as described above (at this time, the SLD integrated intake air correction amount qair / sld also becomes “0”), so the basic learning correction coefficient vpskisld Is forcibly set to “1”.

[0310] In step 15-11, f / flrnend =
1, ie, the basic learning correction coefficient vpskis
If the calculation of ld is to be terminated, STEP1
The processing of 5-12 is omitted, and the basic learning correction coefficient vpskisld
Is not performed (in this case, the basic learning correction coefficient vp obtained in the control cycle before f / flrnend = 1).
The value of skisld is determined as its final value.)

[0311] Thus, STEPs 5-11 and 5-1 are performed.
After performing the processing of step 2, the intake air amount operating means 25
The value of the preliminary opening command θi / fire obtained in P15-10 is limited to a value between a predetermined upper limit value and a lower limit value (when θi / fire> upper limit value or θi / fire <lower limit value, θi / fire respectively. /
After performing the limit process (forcibly restricting the fire to the upper limit value and the lower limit value) (STEP 15-13), the process returns to the routine process of FIG.

Returning to the description of FIG. 14, after obtaining the preliminary opening command θi / fire as described above, the intake air amount operating means 25
Is the preliminary opening command θi / fire (= θ0 + i / sld−θde
c) The atmospheric pressure correction coefficient kpa determined in STEP 14-2, the atmospheric temperature correction coefficient kta, and the learning correction coefficient kilearn determined at the end of the previous operation of the FIRE mode.
(The calculation of the learning correction coefficient kilearn will be described later) to determine the bypass opening command value θCMD in the current control cycle (STEP 1).
4-4). Then, the process returns to the main routine process of FIG.

The process described above is a process for determining the bypass opening command value θCMD in each control cycle in the FIRE mode.

On the other hand, when the current value of the FIRE execution enable / disable flag f / fireon is "0", that is, when the operation of the FIRE mode is not performed (step S14-1). Basically, after the internal combustion engine 1 is started, the FIRE elapsed time t / fire has reached the FIRE mode limit time TFIREMT and the operation in the FIRE mode has been terminated. Is F
The value of the IRE execution availability flag f / fireon in the previous control cycle is determined (STEP 14-5).

At this time, the FIRE execution availability flag f / fire
When the value of on in the previous control cycle is “1”, that is, when the operation in the FIRE mode has been performed until the previous control cycle (the state immediately after the FIRE mode is ended), the operation has been performed up to immediately before. In the FIRE mode, the opening command is corrected in the next operation in the FIRE mode from the basic learning correction coefficient vpskisld finally obtained by the processing in STEP 15-12 as shown in the flowchart of FIG. 18 (STEP 14-4. Then, a learning correction coefficient kilearn is determined (updated) (STEP 14-6).

That is, referring to FIG. 18, first, the learning end time parameter t / kil representing the FIRE elapsed time t / fire at the time when the calculation of the basic learning correction coefficient vpskisld is finally ended is set in advance. Set value TMKILLMT
It is determined whether or not this is the case (STEP 18-1). Here, as shown in FIG. 5, the learning end time parameter f / flrnend is set to “0” for the learning end time parameter t / kil.
FIRE elapsed time t / fi when switching from "1" to "1"
re. That is, when the interruption operation of the FIRE mode is performed, the FIRE elapsed time until the start of the interruption operation
When performing the ignition timing responsive correction processing during the operation of the FIRE mode in t / fire, the FIR until the start of the processing is performed.
The RE elapsed time is t / fire. Then, the FIRE mode is not interrupted and the ignition timing response correction process is not performed.
When the operation in the IRE mode ends, the FIRE elapsed time t / fire at the end of the operation (this is usually the FIRE mode limit time TFIRELMT).

In other words, the learning end time parameter t / kil is used for continuously calculating the SLD opening correction amount i / sld and correcting the standard opening command value θ0 in accordance with the calculation. FIRE elapsed time t / fire.

At step 18-1, t / kil is determined.
In the case of <TMKILLMT, it is considered that the reliability of the finally obtained basic learning correction coefficient vpskisld is poor.
With the learning correction coefficient kilearn maintained at the current value, FIG.
It returns to the processing of.

On the other hand, when t / kil ≧ TMKILLMT, that is, the process of calculating the SLD opening correction amount i / sld and the correction of the standard opening command value θ0 corresponding thereto are continuously performed for a relatively long time. In this case, a new learning correction is performed by the smoothing calculation processing (filtering processing) of the above equation (37) from the basic learning correction coefficient vpskisld finally obtained in the operation in the FIRE mode performed until the previous control cycle. The coefficient kilearn (j) is obtained (STEP 18-2). Then, the learning correction coefficient kilearn (j) is limited to a value between a predetermined upper limit and a lower limit (when kilearn (j)> upper limit or kilearn (j) <lower limit, kilearn (j) is used, respectively). Is forcibly limited to the upper limit value and the lower limit value) (STEP 18-3), and the process returns to the routine process of FIG.

The initial value of the learning correction coefficient kilearn (j) is “1”. The value of the learning correction coefficient kilearn (j) is stored and held in a nonvolatile memory such as an EEPROM so as not to be lost even when the operation of the system according to the present embodiment is stopped.

Returning to the description of FIG. 14, STEP 14-5
When the value of the FIRE execution feasibility flag f / fireon in the previous control cycle is “1”, the learning correction coefficient kilearn is updated as described above. Is "0"
In the case of, since the learning correction coefficient kilearn has already been updated, the processing in STEP14-6 is omitted. That is, the update processing of the learning correction coefficient kilearn is performed only in the control cycle immediately after the end of the FIRE mode, and the updated learning correction coefficient kilearn is updated in the next FI file.
It is used to correct the opening command when operating in the RE mode.

Thus, STEPs 14-5 and 14-
6, the intake air amount operating means 25 sets the opening command θCMD to the opening command for the normal mode (ST
EP 14-7). This opening command is basically based on the FIR
The opening degree command θCMD in the E mode is smaller than the opening command θCMD, and is set to a required value for performing a normal operation of the internal combustion engine 1.

The processing described above with reference to FIGS. 14 to 18 is the details of the processing for generating the opening command (command value of the bypass opening) θCMD in each control cycle in STEP 4-5 in FIG. And the opening command θ determined in this way.
CMD is given to the bypass valve actuator 24. The bypass valve actuator 24 operates the opening of the bypass valve 7 in accordance with the given opening command θCMD.

Next, the process of generating the ignition timing command value iglog in STEP 4-6 in FIG. 4 will be described.

Here, before describing the specific contents of this processing, the basic contents of this processing will be described.

In the system of the present embodiment, the rotation speed Ne (actual rotation speed) of the internal combustion engine 1 tends to increase due to the above-described intake air amount increase control in the FIRE mode. Feedback control is performed to the required target rotation speed ne / fire by the timing operation rotation speed F / B control to correct the ignition timing to the retard side (ignition timing operation rotation speed F / B control). In this case, as described later, it is preferable to variably set the decay speed of the deviation between the rotation speed Ne and the target rotation speed ne / fire (this corresponds to the gain of the feedback control).

For this reason, in the ignition timing operation rotational speed F / B control in the system of the present embodiment, as in the case of the intake air amount F / B control correction processing, the decay speed of the deviation is designated. Sliding mode control (adaptive sliding mode control in this embodiment), which is a possible response assignment type control, is used.

The process of the ignition timing operation rotational speed F / B control using the adaptive sliding mode control (hereinafter, referred to as ignition timing side adaptive SLD control), that is, the rotational speed Ne
The algorithm for generating the ignition timing command value iglog so as to converge to the target rotational speed ne / fire is constructed as follows.

First, in this embodiment, the ignition timing side adaptation S
The control target of the LD control is considered to be a system that generates data representing the rotation speed Ne (actual rotation speed) from data representing the ignition timing command value iglog, and is modeled by a discrete system (discrete time system). .

In this case, in this embodiment, a command value iglog of the ignition timing, a predetermined reference command value ig0, and a deviation DIG (= iglog
−ig0. Hereinafter, an ignition timing deviation command value DIG) will be used as data representing the ignition timing command value iglog, and the deviation DNE between the rotation speed Ne and a predetermined reference rotation speed Ne0 will be described.
(= Ne-Ne0; hereinafter, referred to as deviation rotational speed DNE) is used as data representing the rotational speed Ne.

In this embodiment, the basic command value igbase shown in FIG. 3 (the command value of the ignition timing during normal operation other than the FIRE mode of the internal combustion engine 1) is used as the reference command value ig0 for the ignition timing. (Ig0 = igbase). Accordingly, the correction amount DIG shown in FIG. 3 is the ignition timing deviation command value DIG. In this embodiment, the predetermined idling rotational speed NOBJ shown in FIG. 3 is used as the reference rotational speed Ne0 related to the rotational speed Ne (Ne0 = NOBJ).

In this embodiment, using the above-mentioned ignition timing deviation command value DIG and deviation rotational speed DNE, the model of the control object of the ignition timing side adaptive SLD control is discretely expressed by the following equation (38). It is represented by a system model (a second-order autoregressive model in the present embodiment).

[0333]

(38)

The model of the control object represented by the equation (38) (hereinafter referred to as the rotation speed control object model) is the deviation rotation speed DNE (k + 1) in each control cycle as the output of the rotation speed control object model. , The deviation rotation speed in the past
DNE time series data DNE (K) and DNE (k-1), and the ignition timing deviation command value DIG as an input of the rotation speed control target model
(k).

In equation (38), the deviation rotational speed DNE (K),
The coefficients c1 and c2 relating to DNE (k-1) and the coefficient d1 relating to the ignition timing deviation command value DIG (k) are model parameters that define the actual behavior characteristics of the rotation speed control target model. The model parameters c1, c2, and d1 are previously identified through experiments, simulations, and the like so that the behavior characteristics of the rotation speed control target model and the behavior characteristics of the actual control target expressed by the model match.

In this case, since the rotation speed control target model is a discrete system model, various known identification algorithms (for example, deviation rotation speed DN generated on the rotation speed control target model)
The model parameters c1, c2, d are obtained by the least squares method so that the error between E (k + 1) and the actual deviation rotation speed is minimized.
The algorithm can identify the model parameters c1, c2, and d1 relatively easily using an algorithm for identifying (1).

The algorithm of the ignition timing side adaptive SLD control process is constructed as follows based on the rotation speed control target model determined in this manner.

That is, in the ignition timing side adaptive SLD control, the switching function σ 2 required for the sliding mode control is set.
In the same manner as in the case of the intake side adaptive sliding mode control described above, a time series of a deviation En = DNE−dne (hereinafter, referred to as a rotational speed deviation En) between the differential rotational speed DNE and its target value dne in each control cycle. It is defined by a linear function of the following equation (39) using the data En (k) and En (k-1) as variables. Note that the target value dne of the deviation rotation speed DNE (hereinafter referred to as the deviation target rotation speed dne
Is the deviation (= ne / fire-Ne0) between the target rotational speed ne / fire shown in FIG. 3 and the reference rotational speed Ne0 (= idling rotational speed NOBJ). Therefore, the rotational speed deviation En = DNE-dne is the same as the deviation (= Ne-ne / fire) between the rotational speed Ne (actual rotational speed) and the target rotational speed ne / fire.

[0339]

[Equation 39]

Here, s3 and s4 in the equation (39) are coefficient parameters of each term of the switching function σ2, and are set so as to satisfy the following condition.

[0341]

(Equation 40)

In this embodiment, s3 is used for simplicity.
= 1. The value of the coefficient parameter s4 (more generally, the value of s4 / s3 = pole / ig) is variably set, which will be described later.

When the switching function σ2 is defined as described above,
As in the case of the intake side adaptive sliding mode control,
A state quantity (En (k), En (k-1)) composed of a set of time series data En (k), En (k-1) of the rotational speed deviation En is defined by a relational expression σ2 = 0. When the convergence state is maintained on the switching line, and the convergence state is maintained, the state quantities (En (k), En (k-1))
Is extremely stable without being affected by disturbances or the like.
It can be converged to an equilibrium point on 0, that is, a point where En (k) = En (k-1) = 0.

The deviation rotation speed DNE is converged to the deviation target rotation speed dne (the rotation speed Ne is reduced to the target rotation speed ne / f).
The control input generated by the ignition-timing-side adaptive SLD control as an input to be given to the control object modeled by the above equation (39), that is, the ignition-timing deviation command value DIG is set to the intake-side adaptive sliding mode. As in the case of control, equivalent control input DIGeq and reaching law input DIGr
This is the sum of ch and the adaptive law input DIGadp (see the following equation (41)).

[0345]

[Equation 41]

The equivalent control input DIGeq, the reaching law input DIGrch, and the adaptive law input DIGadp are given by the following equations (42) to (44), respectively, as in the case of the intake-side adaptive sliding mode control.

[0347]

(Equation 42)

[0348]

[Equation 43]

[0349]

[Equation 44]

Then, in this case, the coefficient F in the equation (43)
3 (the coefficient that defines the gain of the reaching law) is given by the following equation (4
5), more preferably, is set in advance so as to satisfy the condition of (45) '.

The coefficient F4 (coefficient for defining the gain of the adaptive law) in the equation (44) is set in advance so as to satisfy the condition of the following equation (46). Note that ΔT in the equation (46) is a control cycle (control cycle).

[0352]

[Equation 45]

[0353]

[Equation 46]

The adaptive SLD on the ignition timing side in this embodiment
In the control, the equations (42) to (4) are used for each control cycle.
4) An equivalent control input DIGeq, a reaching law input DIGrch, and an adaptive law input DIGadp are obtained, and the sum of them is calculated (Equation (41)) to obtain an ignition timing deviation command value DIG. Then, the ignition timing deviation command value DIG is added to the reference command value ig0, that is, the basic command value igbase during normal operation of the internal combustion engine 1 as shown in the following equation (47), so that the ignition timing command Determine the value iglog.

[0355]

[Equation 47]

In this case, the target deviation rotational speed dne required to obtain the equivalent control input DIGeq and the value of the switching function σ2
Is determined as follows.

That is, in this embodiment, when the rotation speed Ne (actual rotation speed) of the internal combustion engine 1 reaches the set rotation speed (= NOBJ + NEFSLDS) shown in FIG.
The ignition timing operation speed F / B control is started when the E elapsed time t / fire reaches a predetermined value TSLDIGST. The target rotational speed ne / fire of the internal combustion engine 1 in the FIRE mode is the elapsed time Δt / nfb (hereinafter referred to as the rotational speed F / B elapsed time Δt / nfb) from the start of the ignition timing operation rotational speed F / B control. ) Is set according to the following equation (48).

[0358]

[Equation 48]

Here, K / NE in the equation (48) is a constant predetermined value (> 0) which defines the degree of temporal decrease (gradient) of the target rotational speed ne / fire.

In this case, when the calculation result on the right side of the equation (48) is lower than the idling rotational speed NOBJ (Δ
t / nfb> NEFSLDS / K / NE), the target speed ne / f
Fix ire to idling speed NOBJ.

Thus, the target rotational speed ne / fire gradually decreases linearly from the set rotational speed (= NOBJ + NEFSLDS) toward the idling rotational speed NOBJ after the start of the ignition timing operation rotational speed F / B control. , The idling speed NO
After reaching BJ, the idling rotational speed NOBJ is maintained.

Therefore, in the present embodiment, the target rotation speed ne / fire (k) in each control cycle is calculated by the equation (48) from the rotation speed F / B elapsed time Δt / nfb in the control cycle.
By subtracting the idling rotational speed NOBJ from the target rotational speed ne / fire (k), a deviation target rotational speed dne (k) (= ne / fire (k) -NOBJ) in each control cycle is determined. Can be Then, the deviation target rotational speed dne (k) and its previous value dne (k-1) (= ne / fire (k-1) -NOBJ), that is, the deviation target rotational speed dne (dne (dne) obtained in the previous control cycle) By using (k-1), the value of the switching function σ2 (k) can be obtained from the above equation (39) for each control cycle. And
By using the value of this switching function σ2, the above equation (4)
3), reaching rule input DIGrch and adaptive law input according to (44)
DIGadp can be obtained.

In this embodiment, the control cycle (T
DC) is inversely proportional to the rotational speed Ne of the internal combustion engine 1,
The time ΔT (∝) for one control cycle from the current rotational speed Ne
1 / Ne), and the time ΔT is added to the current rotational speed F / B elapsed time Δt / nfb to predict the rotational speed F / B elapsed time (= Δt / nfb + ΔT) in the next control cycle. (Hereinafter, this predicted value is referred to as the rotation speed F /
B predicted elapsed time Δt / nfbpre). Then, the rotation speed F / B predicted elapsed time Δt / nfbpre is applied to the above equation (48) (substituting Δt / nfbpre for Δt / nfb on the right side of the equation (48)) to obtain the following equation (49). Thus, the target rotation speed ne / fire (k + 1) in the next control cycle can be obtained.

[0364]

[Equation 49]

Further, by subtracting the idling rotational speed NOBJ from the target rotational speed ne / fire (k + 1), the deviation target rotational speed dne (k + 1) (= ne / fire (k +) in the next control cycle is obtained.
1) -NOBJ) is required.

Then, using the deviation target rotational speed dne (k + 1) obtained in this way and the deviation target rotational speeds dne (k), dne (k-1) obtained as described above, By performing the calculation of 42), the equivalent control input DIGeq can be obtained.

In this embodiment, during the interruption operation of the FIRE mode, the ignition timing operation speed F / B control is interrupted.
The ignition timing command value iglog is returned to the basic command value igbase during normal operation of the internal combustion engine 1. In this case, after the interruption operation is started, the value (absolute value) of the ignition timing deviation command value DIG in the equation (47) is changed to a predetermined unit value dec / ig for each control cycle until the value becomes “0”. The ignition timing command value iglo is gradually reduced (slowly approaching “0”).
g is gradually returned to the basic command value igbase. Then, when the interruption operation is released, the ignition timing operation speed F / B control is immediately restarted.

In this embodiment, the operation in the FIRE mode is completed (the FIRE execution enable / disable flag f / fireon changes from “1” to “0”), and the operation mode of the system shifts to the normal mode. The ignition timing command value iglog is gradually returned to the basic command value igbase.

The contents described above are the basic contents of the processing of the ignition timing operation speed F / B control in this embodiment.

Incidentally, in the ignition timing side adaptive SLD control which is the response designation type control, the intake side adaptive SL
Similarly to the D control, the coefficient parameter s3 of the switching function σ2
, S4 (hereinafter referred to as the pole pole / ig), the rotational speed deviation En
(= DNE-dne = Ne-ne / fire) can be specified. That is, pole pole / ig (= s4 /
As the absolute value of s3) approaches "0" within a range smaller than "1", the decay speed of the rotational speed deviation En increases.
In the present embodiment, as in the case of the intake side adaptive SLD control, s4 / s3 = pole / ig <0 in order to avoid vibrational attenuation of the rotational speed deviation En.

By utilizing the response designation characteristics of the ignition timing side adaptive SLD control, in the present embodiment, the decay speed of the rotational speed deviation En is variably set as follows.

That is, the change in the rotation speed Ne of the internal combustion engine 1 with respect to the change in the ignition timing tends to increase as the ignition timing is more retarded. Therefore, in order to stably control the rotation speed Ne to the target rotation speed ne / fire, the decay speed of the rotation speed deviation En is made slower as the operated ignition timing is on the retard side. (Increase the absolute value of the pole pole / ig) is considered preferable.

Therefore, in the present embodiment, for each control cycle, the current ignition timing command value iglog (the command value iglog determined in the previous control cycle) is determined based on a data table predetermined as shown in FIG. Pole
The basic value pole / igtbl of / ig is obtained, and this basic value pole / igtbl is basically set as the value of the pole pole / ig. In this case, the basic value pole / igtbl (hereinafter referred to as the ignition timing corresponding pole basic value pole / igtbl) is the command value iglog of the ignition timing.
Is set to increase the absolute value | pole / igtbl | as the angle is more retarded (where −1 <pole / igtbl <
0).

Incidentally, the basic value of the pole corresponding to the ignition timing pole / igtbl
Is basically set to a value closer to “0” side than the pole table value pole / itbl determined by the data table of FIG. 9 for the intake side adaptive SLD control. In other words, with respect to the ignition timing adaptive SLD control, the decay rate of the rotational speed deviation En defined by the ignition timing corresponding pole basic value pole / igtbl is equal to the intake adaptive SLD.
Regarding the control, the ignition timing corresponding pole basic value pole / igtbl is set so as to be faster than the decay rate of the intake deviation Eq specified in the pole table value pole / itbl.

In this embodiment, when starting the ignition timing operation rotation speed F / B control, the rotation speed Ne is changed to the target rotation speed ne / f by the above-described ignition timing side adaptive SLD control processing.
If the ignition timing is suddenly changed to converge to ire,
The combustion state of the internal combustion engine 1 may be deteriorated. Therefore,
In the initial stage of the ignition timing operation rotational speed F / B control, the pole pole / ig is set so as to slow down the decay rate of the rotational speed deviation En.
Is preferably set.

Therefore, in the present embodiment, in each control cycle, the rotational speed F / B elapsed time Δt / nfb (the elapsed time from the start of the ignition timing operation rotational speed F / B control) is shown in FIG. As shown, the basic value of the pole corresponding to the ignition timing based on a predetermined data table (time table)
A correction coefficient kigt for correcting (multiplying correction) the / igtbl in accordance with the rotation speed F / B elapsed time Δt / nfb is obtained, and this correction coefficient kigt (hereinafter referred to as a time-dependent correction coefficient kigt) is used as the ignition timing pole basic. By multiplying the value pole / igtbl, the ignition timing corresponding pole basic value pole / igtbl is corrected.

In this case, in the data table of FIG.
The time-dependent correction coefficient kigt is set at an initial stage of the ignition timing operation rotation speed F / B control (the rotation speed F / B elapsed time Δt / nfb is a predetermined value
Until T / NFBX is reached), the basic value of the ignition timing pole
The value (> 1) is set such that the ignition timing-corresponding pole basic value pole / igtbl is corrected in a direction in which the absolute value of pole / igtbl is slightly increased (direction in which the decay rate of the rotational speed deviation En is reduced). . Moreover, at this time, the time corresponding correction coefficient kigt
Is set to a larger value as the rotation speed F / B elapsed time Δt / nfb is shorter, whereby the rotation speed F / B elapsed time Δt / nf
As b is shorter, the ignition timing-corresponding pole basic value pole / igtbl is set such that the absolute value of the ignition timing-corresponding pole basic value pole / igtbl becomes larger (the decay rate of the rotational speed deviation En becomes slower).
bl is corrected. After the rotation speed F / B elapsed time Δt / nfb has reached the predetermined value T / NFBX, the time corresponding correction coefficient kigt is held at “1”. In this state, the ignition timing corresponding pole basic value pole / igtbl Is not corrected.

Further, in this embodiment, during the interruption operation of the FIRE mode, the ignition timing operation rotational speed F / B control is interrupted, and the feedback operation of the rotational speed Ne is not performed. Timing operation speed F / B
When the control is restarted, the rotation speed of the internal combustion engine 1 is changed to the target rotation speed.
May be significantly higher than ne / fire. In such a state, the rotational speed deviation En
Becomes larger, the ignition timing command value iglo obtained by the ignition timing operation speed F / B control as described above.
g suddenly becomes excessively large on the retard side, and the combustion state of the internal combustion engine 1 may be deteriorated. Accordingly, when the ignition timing operation speed F / B control is resumed by canceling the interruption operation of the FIRE mode, the speed Ne of the internal combustion engine 1 is largely separated from the target speed ne / fire toward the high speed side. In such a situation, the decay speed of the rotational speed deviation En is slowed down, so that the ignition timing deviation command value DIG which makes the ignition timing command value iglog excessively retarded is avoided. It is considered preferable.

Therefore, in the present embodiment, the ignition timing corresponding pole basic value pole / igtbl is calculated for each control cycle from the current rotational speed Ne of the internal combustion engine 1 based on a predetermined data table as shown in FIG. A correction coefficient kigne for correction (multiplication correction) according to the rotation speed Ne (hereinafter, referred to as a rotation speed corresponding correction coefficient kigne) is obtained. in this case,
In the data table of FIG. 21, the correction coefficient kign
e is basically the absolute value of the basic value pole / igtbl of the pole corresponding to the ignition timing as the rotational speed Ne increases (the rotational speed Ne is further away from the target rotational speed ne / fire on the high rotational side). Is set to a value (> 1) such that the ignition timing corresponding pole basic value pole / igtbl is corrected in a direction in which is increased (a direction in which the decay rate of the rotational speed deviation En is reduced). In the present embodiment, the correction of the ignition timing corresponding pole basic value pole / igtbl based on the rotation speed corresponding correction coefficient kigne is performed for a predetermined period XCNT after the restart of the ignition timing operation rotation speed F / B control. In order to perform only the countdown timer cnt / igvpl set in STEP5-18 of STEP 3), the rotational speed-dependent correction coefficient kigne is corrected by the following equation (50), and the corrected correction coefficient kignef (hereinafter referred to as rotation) is corrected. The correction coefficient kignef corresponding to the number is referred to as the basic pole value pole / i corresponding to the ignition timing.
By multiplying gtbl, the ignition timing corresponding pole basic value po
Correct le / igtbl.

[0380]

[Equation 50]

Here, the countdown timer cnt / igvpl in the equation (50) is determined by STEP5-18 in FIG.
During suspend operation (FIRE suspend flag f / fpause = 1)
The predetermined period XCNT is always set. Then, when the ignition timing operation speed F / B control is resumed due to the release of the interruption operation, the value of the countdown timer cnt / igvpl decreases by a predetermined value for each control cycle from the value of the XCNT for a predetermined period. After it becomes "0", it is held at that value.
Therefore, the rotational speed corresponding correction correction coefficient kignef obtained by the equation (50) is a value (≧ 1) corresponding to the rotational speed Ne until the predetermined period XCNT elapses after the ignition timing operation rotational speed F / B control is restarted. However, after the elapse of the predetermined period XCNT, kignef = 1 (at this time, the ignition timing corresponding pole basic value pole / igtbl based on the rotational speed corresponding correction correction coefficient kignef).
Is no longer corrected).

Note that the countdown timer cnt / igvpl is:
"0" in the start mode process (STEP3-2)
The value is held at "0" except during the interruption operation of the FIRE mode and during the period from the end of the interruption operation until the predetermined period XCNT elapses.

In this embodiment, the ignition timing corresponding pole basic value pole / igtbl
Then, a value obtained by multiplying the time-corresponding correction coefficient kigt and the rotational-speed-correction correction coefficient kignef as in the following equation (51) is set as a final pole pole / ig value.

[0384]

(Equation 51)

The time-dependent correction coefficient kigt can be obtained only in the initial stage immediately after the start of the ignition timing operation speed F / B control.
kigt> 1, and in other states, kigt = 1. Further, the rotational speed corresponding correction correction coefficient kignef is calculated by
Kignef> 1 only in the initial stage immediately after the cancellation of the mode interruption operation and when the rotation speed Ne is relatively high, and kignef = 1 in other states. Therefore, the value of the pole pole / ig set by the equation (51) is usually the ignition timing corresponding pole basic value pole / igtbl.

Based on the contents described above, the generation process of the ignition timing command value iglog performed by the ignition timing operation means 26 in STEP 4-6 in FIG. 4 will be specifically described below.

Referring to the flowchart of FIG. 22, in STEP 4-6, the ignition timing operation means 26 first
The basic command value igbase of the ignition timing is determined (STEP 22).
-1). In this case, the basic command value igbase is, for example, the current rotational speed Ne of the internal combustion engine 1, the intake pressure Pb, the engine temperature T
From w, the atmospheric temperature Ta, and the like, it is obtained using a predetermined map or arithmetic expression.

Next, the ignition timing operating means 26 executes a process for determining the ignition timing deviation command value DIG as shown in the flowchart of FIG. 23 (STEP 22-).
2).

That is, in the processing of STEP 22-2,
First, the value of the current FIRE execution availability flag f / fireon is determined (STEP 23-1).

At this time, f / fireon = 1, ie, FI
When the operation in the RE mode is to be performed, the ignition timing operation means 26 determines whether or not to perform the ignition timing operation rotation speed F / B control by means of a flag f / ne indicating by a value "1" or "0", respectively.
fb (hereinafter referred to as rotation speed F / B execution availability flag f / nefb)
Is determined (STEP 23-2).

This rotational speed F / B execution availability flag f / nefb
Is initialized to "0" in the start mode process (STEP 4-2).

In this STEP 23-2, f / nefb =
0, that is, when it is not in a state to perform the ignition timing operation rotation speed F / B control yet, the value of the rotation speed F / B elapsed time Δt / nfb is initialized to “0” (STEP 23-).
3). The rotation speed F / B elapsed time Δt / nfb is calculated in STEP 2
In 3-2, f / nefb = 1, and the ignition timing operation speed F /
Time measurement is started from the control cycle in which the B control should be performed. If f / nefb = 1 in STEP 23-2, the processing in STEP 23-3 is omitted.

Next, the ignition timing operating means 26 obtains the target rotation speed ne / fire (k) in the current control cycle and the target rotation speed ne / fire (k + 1) in the next control cycle (STEP 23-). 4). In this case, the target rotation speed ne / fire (k) in the current control cycle is equal to the current rotation speed F /
It is obtained from the equation (48) from the B elapsed time Δt / nfb. Also, the target rotation speed ne / f in the next control cycle
Regarding ire (k + 1), the current rotational speed Ne of the internal combustion engine 1 is
(The detected value of the rotation speed sensor 14), the time ΔT of one control cycle is taken as the current rotation speed F / B elapsed time Δt / nf
b, the rotation speed F / B predicted elapsed time Δt / nfbp
re is obtained, and the target rotation speed ne / fire (k + 1) is obtained from the rotation speed F / B estimated elapsed time Δt / nfbpre by the above equation (49).

The target rotational speed ne / fire (k) in this control cycle is determined by the rotational speed F / B elapsed time Δt / nfb being equal to ST.
While it is set to “0” in EP23-3 (f / nefb = 0
State) is the set rotation speed (NOBJ + NEFSLDS).

Next, the ignition timing operating means 26 determines that the current rotational speed Ne of the internal combustion engine 1 is the current target rotational speed ne / fire (k).
Whether or not it is above (STEP23-5), the current FI
It is sequentially determined whether or not the RE elapsed time t / fire has become equal to or longer than a predetermined value TSLDIGST (constant value) (STEP 23-6).

When any one of the conditions in STEPs 23-5 and 23-6 is satisfied, the value of the rotational speed F / B execution availability flag f / nefb is set to "1" (STEP 23).
-7). As a result, after the start of the operation in the FIRE mode, the rotation speed Ne of the internal combustion engine 1 is changed to the set rotation speed (NOBJ).
+ NEFSLDS) or when the FIRE elapsed time t / fi
When re reaches the predetermined value TSLDIGST, the rotation speed F / B execution enable / disable flag f / nefb is set to “1”, and a state is established in which the ignition timing operation rotation speed F / B control can be performed.

If none of the conditions of STEPs 23-5 and 23-6 are satisfied, the processing of STEP 23-7 is omitted, and the value of the rotation speed F / B execution availability flag f / nefb is set to "0". Will be maintained. Further, the rotational speed F / B execution availability flag f / nefb is not returned to “0” during the operation of the FIRE mode after being set to “1”.

Next, the ignition timing operating means 26 determines the rotational speed in the present control cycle from the current rotational speed Ne of the internal combustion engine 1 and the current target rotational speed ne / fire (k) obtained in STEP 23-4. Deviation En (k) (= Ne-ne / fire
(k)) is calculated (STEP 23-8).

Next, the ignition timing operating means 26
The value of the IRE interruption flag f / fpause is determined (STEP 23).
-9), when f / fpause = 0, that is, when the FIRE mode is not in the state of performing the interruption operation, the rotation speed F / B is further increased.
Judge the value of the feasibility flag f / nefb (STEP 23-
10).

At this time, if f / nefb = 0, the value of the ignition timing deviation command value DIG (k) in this control cycle is set to “0” (STEP 23-11), and the routine proceeds to the routine of FIG. Return.

On the other hand, if f / nefb = 1 in STEP 23-10, the ignition timing deviation command value DIG (k) for the ignition timing operation speed F / B control is calculated (STEP 23-).
12).

The calculation of the ignition timing deviation command value DIG (k) is performed as follows.

That is, referring to the flowchart of FIG. 24, first, the current ignition timing command value iglog (k-1) (the command value determined in the previous control cycle) is obtained from the data table of FIG. Pole basic value for ignition timing po
le / igtbl is determined (STEP 24-1).

The current rotation speed F / B elapsed time Δt / nf
The time-corresponding correction coefficient kigt is obtained from b using the data table of FIG. 20 (STEP 24-2).

Further, from the current rotational speed Ne of the internal combustion engine 1, the rotational speed corresponding correction coefficient kigne is obtained from the data table of FIG. 21 (STEP 24-3), and the rotational speed corresponding correction coefficient kigne and the countdown are calculated. From the current value of the timer cnt / igvpl and the predetermined period XCNT predetermined as the initial value of the countdown timer cnt / igvpl after the end of the interruption operation of the FIRE mode, the above equation (5) is obtained.
0), the rotational speed corresponding correction correction coefficient kignef is obtained (STEP 24-4).

Then, the ignition timing corresponding pole basic value pole / igtbl obtained in STEP 24-1 is multiplied by the time corresponding correction coefficient kigt and the rotational speed corresponding correction correction coefficient kignef obtained in STEPs 24-2 and 24-4, respectively ( Equation (51)
Is calculated, the value of the pole pole / ig in the current control cycle is determined (STEP 24-5).

Next, the ignition timing operation means 26 performs the above-mentioned STEP 2 in the current and previous control cycles, respectively.
From the rotational speed deviations En (k) and En (k-1) obtained in 3-8 and the current value of the pole pole / ig obtained in the above STEP24-5, the present control is performed by the calculation of the above equation (39). The switching function σ2 (k) in the cycle is obtained (STEP 24-
6). In this case, the coefficient parameters s3 and s4 in equation (39) are "1" and "pole / ig", respectively.

Next, the ignition timing operation means 26 obtains the equivalent control input DIGeq, the reaching law input DIGrch, and the adaptive law input DIDadp in the current control cycle, respectively, according to the equations (42) to (44) (STEP 24-7). ).

More specifically, regarding the equivalent control input DIGeq, first, in this control cycle, the STE
Target rotation speed ne / fire (k) and ne / fire obtained in P23-4
(k + 1) and STEP23− in the previous control cycle.
From the target rotation speed ne / fire (k-1) obtained in step 4, the above-mentioned criteria for the target rotation speeds ne / fire (k), ne / fire (k + 1) and ne / fire (k-1) are obtained. The deviation from the rotation speed Ne0 (= idling rotation speed NOBJ), that is, the deviation rotation speeds dne (k), dne (k + 1), dn
Find e (k-1). Then, the deviation rotational speeds dne (k), dne
(k + 1) and dne (k-1), the rotational speed deviations En (k) and En (k-1) obtained in the above-described STEP23-8 in the current and previous control cycles, and obtained in STEP24-5. The equivalent control input DIGeq (k) is obtained by performing the calculation of Expression (42) using the current value of the pole pole / ig. In this case, the coefficient parameters s3 and s4 in the equation (42)
Are "1" and "pole / ig", respectively. The model parameters c1, c2, d1 in the equation (42) are predetermined values identified in advance for the rotation speed control target model (see the equation (38)).

As for the reaching law input DIGrch (k), the operation of the equation (43) is performed using the value of the switching function σ2 (k) obtained in STEP 24-6.
Is required. In this case, the coefficient parameter s3 in the equation (43) is "1", and the coefficient F3 in the equation (43) is a predetermined value set in advance to satisfy the condition of the equation (45) or (45) '. Value.

Also, regarding the adaptive law input DIDadp, ST
Switching function σ obtained for each control cycle in EP24-6
The cumulative value Σσ2 of the switching function σ2 is obtained by cumulatively adding the value of 2 in each control cycle. Then, the integrated value Σ
The adaptive law input DIDadp is obtained by performing the calculation of the above equation (44) using σ2. In this case, the coefficient parameter s3 in the equation (44) is "1", and the equation (4)
The coefficient F4 in 4) is a predetermined value set in advance so as to satisfy the condition of the above equation (46).

After obtaining the equivalent control input DIGeq, the reaching law input DIGrch, and the adaptive law input DIDadp as described above, the ignition timing operating means 26 calculates the sum of them according to the equation (41), The ignition timing deviation command value DIG (k) in the control cycle of (1) is obtained (STEP 24-8), and the process returns to the routine of FIG.

Returning to the description of FIG. 23, after calculating the ignition timing deviation command value DIG (k) in STEP 23-12 as described above, the ignition timing operating means 26 sets the ignition timing deviation command value DIG (k ) Is limited to a value between the predetermined upper limit and lower limit (when DIG (k)> upper limit or DIG (k) <lower limit, the value of DIG (k) is forcibly set, respectively) After setting the upper limit value and the lower limit value (step 23-1).
3) Return to the routine processing of FIG.

If f / fpause = 1 in step 23-9, that is, if the FIRE mode is to be interrupted, the ignition timing operation speed F / B control is interrupted and the ignition timing is stopped. The basic command value igba
In order to gradually return to se (to gradually return the ignition timing deviation command value DIG to “0”), the unit value dec / ig (> 0, hereinafter the ignition value) defining the return amount of the command value iglog for each control cycle. (Step back unit value dec / ig) (STEP
23-14).

When f / fireon = 1 in STEP 23-1, that is, when the operation of the FIRE mode is terminated or not performed, the ignition timing command value iglog is changed to the basic command value igbase. To gradually return to
The ignition timing return unit value dec / ig is determined (STEP 2
3-15).

In this case, in the present embodiment, STEP 23
In -15, the ignition timing return unit value dec / ig is set to a predetermined value (constant value) determined in advance, but the ignition timing return unit value dec / ig set in STEP23-14 at the time of the interruption operation of the FIRE mode is the current value. (The ignition timing return unit value dec / ig increases as the opening of the throttle valve 5 increases).

[0417] This is for the following reason. That is, FIR
The interruption operation of the E mode is basically performed in a situation where the vehicle is running or the internal combustion engine 1 is overrun by operating the accelerator pedal of the vehicle. At this time, the opening degree of the throttle valve 5 is set to the accelerator operation amount A as described above.
When the throttle valve 5 is operated to an opening degree corresponding to the opening degree of the throttle valve 5 and the opening degree of the throttle valve 5 is large, the ignition timing is set to the normal ignition timing as soon as possible in order to secure required operating performance of the internal combustion engine 1 (this is It is considered preferable to return the basic command value igbase). For this, STEP23-
At 14, the ignition timing return unit value dec / ig is
Is determined to be a value proportional to the opening degree.

In this case, the ignition timing return unit value dec / ig
The opening of the throttle valve 5 required to determine
An opening command value given from the controller 2 to the throttle valve actuator 23 or a detection value of the opening by a sensor (not shown) is used.

Thus, the ignition timing return unit value dec /
After the ignition timing is determined, the ignition timing operating means 26 next determines the current ignition timing deviation command value DIG (this is the ignition timing deviation command value DIG (k-1) determined in the previous control cycle). )
Is smaller than “0”, that is, whether or not the value is on the retard side (STEP 24-16).

If DIG (k-1) <0 (DIG (k-
1) is a value on the retard side), the current ignition timing deviation command value DIG (k-1) is added to the above-mentioned STEP 24-14 or 24-1.
A value (DIG (k-1) + dec / ig) obtained by adding the ignition timing return unit value dec / ig determined in step 5 is determined as the ignition timing deviation command value DIG (k) in the current control cycle (STEP 24-
17), returning to the routine processing of FIG. In this case, if the upper limit value of the ignition timing deviation command value DIG (k) is set to “0” and (DIG (k−1) + dec / ig) becomes larger than “0”, the ignition timing The value of the deviation command value DIG (k) is forcibly set to “0”.

On the other hand, in STEP24-16, DIG (k-1) ≧ 0
(In effect, when DIG (k-1) = 0), the FIR
E Determine the value of the feasibility flag f / fireon (STEP 24)
-18), when f / fireon = 1 (in this case, FIRE
Mode is being interrupted), the ignition timing deviation command value DIG (k) in this control cycle is set to “0” (S
(TEP24-19), and returns to the routine processing of FIG.

[0422] During the interruption operation of the FIRE mode (f / fire
(on = 1 and f / fpause state), the value of the integrated value Σσ2 of the switching function σ2 is held at the value immediately before the start of the interruption operation.

Further, in STEP24-18, f / fireon = 0.
In other words, when the FIRE mode is terminated, the FIRE interruption flag f / fpause and the rotation speed F / B
The value of the feasibility flag f / nefb is reset to “0”, the ignition timing deviation command value DIG (k), the value of the switching function σ2 and its integrated value Σσ2, the equivalent control input DIGeq, and the reaching law input DI
After initializing the values of Grch and the adaptive law input DIGadp to “0” (STEP24-20), the process returns to the routine process of FIG.

Returning to the description of FIG. 22, as described above, ST
After executing the processing for determining the ignition timing deviation command value DIG in EP22-2, the ignition timing operating means 26 executes the processing in STEP22.
By adding the ignition timing deviation command value DIG determined in STEP 22-2 to the basic command value igbase determined in -1, an ignition timing command value iglog in the current control cycle is obtained (STEP 22-3).

Next, the ignition timing operating means 26 determines the ignition timing retard correction limit value IGLGG shown in FIG. 12 for the ignition timing responsive correction processing of the intake air amount operating means 25 described above.
And a threshold value IGX slightly advanced from the limit value IGLGG (STEP 22-4).

In this case, the ignition timing retard side limit value IGLG
G is obtained from the engine temperature Tw of the internal combustion engine 1 based on a data table (not shown), and is determined so that the normal operation of the internal combustion engine 1 can be performed at the advanced ignition timing that is equal to or greater than the limit value IGLGG. The threshold value IGX is equal to the limit value IGLGG.
Is set to a value obtained by adding a predetermined value (constant value) determined beforehand (a value on the advance side by a predetermined value from the limit value IGLGG).
The limit value IGLGG is a constant value when the engine temperature Tw of the internal combustion engine 1 is in a normal temperature range, but is a normal value when the engine temperature Tw is in a considerably low temperature range. The value is set to be more advanced than the temperature range.

Thus, the limit value of the ignition timing on the retard side
After determining the IGLGG and the threshold IGX, the ignition timing operating means 2
Step 6 compares the command value iglog obtained in STEP 22-3 with the threshold value IGX (STEP 22-5). At this time, if the command value iglog is equal to the threshold value IGX or is a value on the advanced side of the threshold value IGX (iglog ≧ IGX), the ignition timing discrimination processing is not performed, so that the ignition timing discrimination is not performed. The value of the flag f / dec (see STEP 15-7 in FIG. 15) is set to “0” (STEP 22-6), and ST
Proceed to EP22-9.

If iglog <IGX in STEP 22-5, the value of the ignition timing determination flag f / dec is set to "1" in order to perform the ignition timing response correction processing (S
TEP22-7) Further, the learning calculation end flag relating to the learning correction process by the intake air amount operating means 25
The value of f / flrnend is determined (STEP 22-8). Then, only when f / flrnend = 0, the ignition timing operating means 26 holds the value of the current FIRE elapsed time t / fire as the value of the learning end time parameter t / kil (STEP 22-9). ) And the basic learning correction coefficient vp
Learning calculation end flag f / fl to end skisld calculation process
Set the value of rnend to “1” (STEP 22-1)
0).

Next, the ignition timing operating means 26
The command value iglog obtained in P22-3 is compared with the retard side limit value IGLGG determined in STEP22-4 (STEP22).
−11), if iglog ≧ IGLGG, that is, the command value
If the iglog is within the limit value IGLGG on the retard side, the process returns to the main routine of FIG.

On the other hand, if iglog <IGLGG, that is, if the command value iglog obtained in STEP22-3 exceeds the limit value IGLGG on the retard side and becomes a value on the retard side, the command value The iglog is forcibly set to the limit value IGLGG (STEP 22-12). Further, at this time, the switching function σ
Forced hold of the integrated value of the value of 2 Σσ2 to the value obtained in the control cycle immediately before iglog <IGLGG
After that (STEP 22-13), the process returns to the main routine of FIG. The reason why the value of the integrated value Σσ2 is held in this manner is that the ignition timing command value iglog is forcibly set to the limit value IGLGG and the calculation of the ignition timing deviation command value DIG is continued by the processing of the above STEP23-12. If this is done, the value of the integrated value Σσ2 of the value of the switching function σ2, and consequently, the value (absolute value) of the adaptive law input DIGadp becomes excessively large.

The processing described with reference to FIGS. 19 to 24 corresponds to the command value of the ignition timing in STEP 4-6 in FIG.
Details of the process of generating iglog for each control cycle,
The command value iglog determined in this way is given to the ignition device 21. Then, the ignition device 21 controls the ignition timing of the internal combustion engine 1 according to the given command value iglog.

By the operation of the system of the present embodiment described above, in the operation in the FIRE mode, the amount of intake air in the combustion chamber 4 of the internal combustion engine 1 is increased by the operation of the bypass opening as compared with the normal idling operation. . In parallel with this, by the ignition timing operation rotation speed F / B control,
The rotational speed Ne of the internal combustion engine 1 is set to the required target rotational speed ne / fire.
(Finally, the ignition timing is operated to the retard side so as to converge to the idling rotational speed NOBJ). As a result, the amount of heat given to the catalyst device 3 by the exhaust gas generated by the combustion of the air-fuel mixture by the internal combustion engine 1 becomes larger than in the normal idling operation, and the temperature rise and activation of the catalyst device 3 are performed early. At the same time, the rotation speed Ne of the internal combustion engine 1, which tends to increase due to an increase in the intake air amount, can be maintained at an appropriate rotation speed.

In this case, regarding the increase of the intake air amount,
The estimated integrated intake air amount qair / pre corresponding to the integrated value of the instantaneous heat amount actually given to the catalyst device 3 after the start of the increase is set to the target integrated value of the heat amount to be actually given to the catalyst device 3. The command value of the bypass opening is corrected by the intake air amount F / B control correction process using the intake side adaptive SLD control so as to converge to the corresponding target integrated intake air amount qair / cmd.

For example, as shown in the middle part of FIG. 25, the estimated integrated intake air amount qair / pre is determined according to the standard opening command value θ0 due to the variation of the intake air amount due to the structural factors. When an error (intake deviation Eq) occurs with respect to qair / cmd, the opening command Θ (command value of the bypass opening) is, as shown in the upper part of FIG. It is corrected by the degree correction amount i / sld. By this correction, the estimated integrated intake air amount qair / pre is made to converge to the target integrated intake air amount qair / cmd as shown in the middle part of the figure, and the integrated value of the amount of heat actually given to the catalyst device 3 is calculated. The target value can be followed. This makes it possible to compensate for variations in the amount of intake air due to the structural factors, and to eliminate variations in the temperature rise mode of the catalyst device 3 due to the structural factors.

Further, in this embodiment, the opening command Θ is multiplied and corrected by the atmospheric pressure correction coefficient kpa and the atmospheric temperature correction coefficient kta obtained by the atmospheric condition correction processing.
That is, the lower the atmospheric pressure Pa, the more the opening command Θ is corrected, and the higher the atmospheric temperature, the more the opening command Θ is corrected. This makes it possible to compensate for variations in the amount of intake air due to atmospheric conditions, and thus to eliminate variations in the temperature rising mode of the catalyst device 3 due to the atmospheric conditions.

As a result, the temperature rising mode of the catalyst device 3 in the FIRE mode can be adjusted to a desired temperature rising mode (in this embodiment, the engine temperature Tw at the time of starting the internal combustion engine 1)
Also, if the shift position of the automatic transmission during the operation of the FIRE mode is constant, the temperature rise mode of the catalyst device 3 by each operation of the FIRE mode is substantially the same, except when the interruption operation of the FIRE mode is performed. ), And the desired temperature rise and activation of the catalyst device 3 by the operation in the FIRE mode can be reliably performed.

Further, the standard opening command value θ0, the target intake air amount gair / cmd, and the target integrated intake air amount qair / c
Since md is set to a value corresponding to the engine temperature Tw at the time of the start of the internal combustion engine 1 corresponding to the temperature state of the catalyst device 3 at the time of the start of the internal combustion engine 1 (basically, as the engine temperature Tw becomes higher, (The target intake air amount gair / cmd and the target integrated intake air amount qair / cmd become smaller), and the temperature of the catalyst device 3 suitable for the temperature state of the catalyst device 3 when the internal combustion engine 1 is started is raised and activated. be able to. That is, the mode of temperature rise of the catalyst device 3 in the FIRE mode (degree of temperature rise over time)
Depends on the temperature state of the catalyst device 3 when the internal combustion engine 1 is started, but the final temperature condition of the catalyst device 3 by the operation in the FIRE mode is appropriately set based on the activation of the catalyst device 3. It can be in a temperature state.

The target integrated intake air amount qair / cmd defined by the standard opening command value θ0 is a corresponding intake air amount to be taken into the combustion chamber 4 of the internal combustion engine 1 for each control cycle, that is, The target intake air amount gair / cmd is
After the E elapsed time t / fire reaches a predetermined value t2 (see FIG. 7) (after the internal combustion engine 1 has warmed up to some extent), it is set to gradually decrease. For this reason, it is possible to prevent the rotation speed Ne of the internal combustion engine 1 from rising even if the friction of each part is reduced due to the progress of the warm-up of the internal combustion engine 1. As a result, it is possible to prevent the ignition timing of the internal combustion engine 1 from being excessively retarded by the ignition timing operation F / B control.

Further, in the present embodiment, the ignition timing command value ig determined by the ignition timing operation speed F / B control.
log is a limit value IGLGG on the retard side at which the ignition timing can be manipulated.
When the threshold value IGX is exceeded, the intake air amount F / B control correction processing is interrupted, and the opening degree command Θ is reduced in a feedforward manner by the ignition timing response correction processing. For this reason, even if the decrease in the friction of the internal combustion engine 1 is larger than expected or occurs early,
It is possible to suppress an increase in the tendency of the rotation speed Ne of the internal combustion engine 1 to increase, and to avoid a situation where the ignition timing is excessively retarded as the ignition timing reaches the limit value IGLGG on the retard side.

In this embodiment, the intake air amount F / B
For the control correction process, use sliding mode control that is not easily affected by disturbance, modeling error of the control target, and disturbance.
In particular, by using adaptive sliding mode control (intake-side adaptive SLD control) using an adaptive law for minimizing the influence of disturbances, etc., the estimated integrated intake air amount qair / pre is reduced to the target integrated intake air amount qair / cmd. Thus, control for converging the integrated value of the amount of heat applied to the catalyst device 3 to the target value can be performed with high stability. As a result, the desired temperature rise and activation of the catalyst device 3 can be performed more reliably.

In the intake-side adaptive SLD control of the intake air amount F / B control correction processing, a discrete system model (a system for generating an integrated intake air amount Qa from the opening degree command Θ) is used as a control object. Since the control target is represented by an intake control target model), the ignition timing side adaptive SLD control algorithm can be constructed to be simpler and more suitable for computer processing than when the control target is represented by a continuous system model.

In particular, by modeling the control object of the intake-side adaptive SLD control in a discrete system, the switching function σ1 used for the intake-side adaptive SLD control can be changed without using the change speed of the intake deviation Eq or the like. It can be configured using time series data of only the deviation Eq. As a result, the SLD
It is possible to improve the reliability of the value of the switching function σ1 necessary for obtaining the opening correction amount i / sld, and thus to improve the reliability of the intake-side adaptive SLD control.

In the intake-side adaptive SLD control, the feedback term Θeq / fb of the equivalent control input Θeq is omitted.
By setting the standard opening command value θ0 corresponding to the feedforward term Θeq / ff as the equivalent control input Θeq in the present embodiment, the model parameters a1, a2, and b1 of the control target model (the intake control target model) are used. Instead, the SLD opening correction amount i / sld can be obtained by a simple algorithm.

The SLD opening correction amount i / sld may be determined using the model parameters a1, a2, and b1. Of course, even in this case, the intake-side adaptive SLD control is performed. Since the model of the control target is constructed by a discrete system, by using a known identification algorithm,
It is possible to accurately identify the values of the model parameters a1, a2, b1.

In the intake air amount F / B control correction processing, as shown in the middle part of FIG. 25, until the SLD correction limit time TISLDLMT elapses immediately after the start of the internal combustion engine 1, the estimated integrated intake The values of the air amount qair / pre and the target integrated intake air amount qair / cmd are forcibly held at "0", and the value of the SLD opening correction amount i / sld is also held at "0".

[0446] Therefore, immediately after the start of the internal combustion engine 1, the SL
The intake air amount F / B control correction process is not performed until the D correction limit time TISLDLMT has elapsed, and the bypass opening is
Standard opening command value θ0 (More precisely, standard opening command value θ
The operation is performed in a feed-forward manner mainly by using a value obtained by multiplying 0 by an atmospheric pressure correction coefficient kpa, an atmospheric temperature correction coefficient kta, and a learning correction coefficient kilearn (see the upper part of FIG. 25).

Therefore, immediately after the start of the internal combustion engine 1, the intake air amount is smoothly increased in a manner similar to the manner in which the standard opening command value θ0 is increased. As a result, the internal combustion engine immediately after the start is started. 1 can be stabilized smoothly, and a favorable emission state of the internal combustion engine 1 can be secured.

Further, when actually starting the intake air amount F / B control correction processing, as shown in the lower part of FIG. 25, the value of the pole pole / i related to the intake side adaptive SLD control is set to FIRE.
"-1" until the elapsed time t / fire reaches the specified value TPOLEX
By gradually increasing from the side (gradiently decreasing | pole / i |), the decay rate of the intake deviation Eq is maintained at the predetermined value until the FIRE elapsed time t / fire reaches the predetermined value TPOLEX.
Slower than after reaching TPOLEX.

As a result, by starting the intake air amount F / B control correction process, it is possible to avoid a situation where the opening degree command Θ and, consequently, the amount of intake air suddenly largely change. , A good emission state of the internal combustion engine 1 can be secured while maintaining the stability of the combustion state of the internal combustion engine 1 at the time.

Also, in this embodiment, the learning correction process learns the SLD opening correction amount i / sld by the intake air amount F / B control correction process for each operation in the FIRE mode.
A learning correction coefficient based on the ratio of the SLD integrated intake air correction amount qair / sld obtained by integrating the LD opening correction amount i / sld during the operation of the FIRE mode to the target integrated intake air amount qair / cmd.
kilearn (basically the basic learning correction coefficient vpskisld)
Ask for. Then, in the next operation of the FIRE mode, the opening command Θ is multiplied and corrected in a feed-forward manner over the entire period of the FIRE mode by the learning correction coefficient kilearn, thereby obtaining the SLD opening correction amount i / sld in the FIRE mode. The correction of the opening command Θ for each control cycle can be minimized. As a result, even when the intake air amount greatly varies due to structural factors, the temporal change pattern of the intake air amount greatly deviates from the pattern of the standard opening command value θ0. Such a situation can be avoided, and stable operation of the internal combustion engine 1 can be performed without impairing the combustion state and the emission state of the internal combustion engine 1.

In this embodiment, the internal combustion engine 1 is operated by operating the accelerator pedal of the vehicle during the operation in the FIRE mode.
In this state, the lashing and the starting and running of the vehicle are performed, and the operation of the internal combustion engine 1 other than the idling operation is performed.
Even in the situation where the interruption operation of the IRE mode is performed, the bypass opening is operated to increase the intake air amount (however, the intake air amount F
/ B control correction process is interrupted)
The calculation of qair / pre and the target integrated intake air amount qair / cmd is continued. Then, after the suspension operation is canceled, the intake air amount F / B control correction process is restarted, and the opening command Θ is corrected so that the estimated integrated intake air amount qair / pre converges to the target integrated intake air amount qair / cmd. I do. For this reason, during the operation of the FIRE mode, the operation of the internal combustion engine 1 other than the idling operation is performed. Even if the operation of interrupting the FIRE mode occurs, the operation of the catalyst device 3 within the FIRE mode limit time TFIRELMT occurs. Temperature rise and activation can be reliably performed.

[0452] Regarding the ignition timing operation rotational speed F / B control, the feedback control process includes the intake air amount F
As in the case of the / B control correction process, by using the adaptive sliding mode control (ignition timing side adaptive SLD control), the stability of the control of the rotation speed Ne of the internal combustion engine 1 to the target rotation speed ne / fire is improved. be able to.

In this case, in particular, the command value iglog of the ignition timing operated for controlling the rotational speed Ne by utilizing the response designation characteristic of the ignition timing side adaptive SLD control which is the response designation type control.
Is more retarded, the rotational speed deviation En (= Ne−ne / f)
ire), so that the pole pole / ig (= s4 / s), which is a parameter defining the decay rate, is decreased.
3) The ignition timing corresponding pole basic value pole / igtbl set as a normal value of 3) is variably determined. That is, in general, the more the ignition timing is on the retard side, the greater the change in the rotation speed Ne of the internal combustion engine 1 with respect to the change in the ignition timing. In such a state, the decay speed of the rotation speed deviation En is reduced. By setting the value of pole pole / ig so that it is delayed, the command value determined by the adaptive SLD control on the ignition timing side
The change in iglog is suppressed, and the rotation speed Ne becomes the target rotation speed ne / fir
Avoid sudden changes to e. Conversely, on the advanced side of the ignition timing, the value of the pole pole / ig is set so that the decay rate of the rotational speed deviation En is increased, so that the rotational speed N
Ensure quick follow-up to target rotational speed ne / fire of e.
As a result, it is possible to enhance stability while ensuring appropriate quick response of control of the rotation speed Ne to the target rotation speed ne / fire.

In the initial stage immediately after the start of the ignition timing operation rotational speed F / B control (until the rotational speed F / B elapsed time Δt / nfb reaches a predetermined value T / NFBX), the decay rate of the rotational speed deviation En is reduced. Is multiplied by the ignition timing corresponding pole basic value pole / igtbl by the time corresponding correction coefficient kigt to determine the pole pole / ig. Thus, it is possible to avoid a situation in which the engine speed Ne fluctuates rapidly immediately after the start of the ignition timing operation engine speed F / B control, and the combustion state of the internal combustion engine 1 deteriorates.

Further, in the present embodiment, when the ignition timing operation speed F / B control is resumed after canceling the interruption operation of the FIRE mode, the speed Ne of the internal combustion engine 1 becomes higher than the target speed ne / fire. The farther away you are on the rotation side,
The pole pole / ig is determined by multiplying and correcting the ignition timing-corresponding pole basic value pole / igtbl by the rotational speed-dependent correction correction coefficient kignef so as to slow down the decay rate of the rotational speed deviation En. Accordingly, when the ignition timing operation speed F / B control is restarted, the speed Ne of the internal combustion engine 1 is reduced to the target speed ne / fire.
When the ignition timing is greatly separated to the high rotation side, the ignition timing command value iglog
Of the internal combustion engine 1 can be suppressed, and a stable operating state of the internal combustion engine 1 can be ensured.

Further, in this embodiment, the intake air flow rate F is larger than the absolute value of the pole pole / ig defining the decay rate of the rotation speed deviation En related to the ignition timing operation rotation speed F / B control.
The absolute value of the pole pole / i that defines the decay rate of the intake deviation Eq related to the / B control correction processing is set to a larger value (see the processing in STEPS 17-7 and 17-8 in FIG. 17). In other words, the pole pole / ig is the rotational speed deviation E
n is set to a value such that the decay speed of n becomes faster than the decay speed of intake deviation Eq. Therefore, the rotation speed Ne of the internal combustion engine 1 is reduced to the target rotation speed by the ignition timing operation rotation speed F / B control.
Feedback control to converge to ne / fire and intake air amount F
/ B control correction processing avoids mutual interference with feedback control for converging the estimated cumulative intake air amount qair / pre to the target cumulative intake air amount qair / cmd, and thereby the rotation speed N of the internal combustion engine 1.
e can be stably controlled to the target rotation speed ne / fire.

In this embodiment, in the ignition timing side adaptive SLD control used for the ignition timing operation speed F / B control,
As a system for generating a deviation rotation speed DNE corresponding to the rotation speed Ne of the internal combustion engine 1 from an ignition timing deviation command value DIG corresponding to the ignition timing command value iglog, a discrete system model (rotation speed control object Expression), the algorithm of the ignition timing side adaptive SLD control can be made simple and suitable for computer processing.

In particular, by modeling the control target of the ignition timing-side adaptive SLD control in a discrete system, the switching function σ2 is changed to the rotational speed deviation En, as in the case of the intake-side adaptive SLD control.
Without using the change speed or the like, the time series data of only the rotational speed deviation En can be used. As a result, the reliability of the value of the switching function .sigma.2 necessary for obtaining the ignition timing deviation command value DIG can be enhanced, and the reliability of the ignition timing side adaptive SLD control can be enhanced.

In this embodiment, the bypass valve 7 is used as a flow control valve for increasing the intake air amount of the combustion chamber 4 of the internal combustion engine 1 in the FIRE mode, but the opening of the throttle valve 5 is operated. Thus, the intake air amount may be increased.

Further, in the above-described embodiment, when the air-fuel ratio of the air-fuel mixture burned in the combustion chamber 4 is constant, the amount of heat generated by the internal combustion engine 1 (the amount of heat of the exhaust gas), and hence the amount of heat given to the catalyst device 3 Is approximately proportional to the amount of intake air in the combustion chamber 4, and therefore, the integrated value of the amount of intake air for each control cycle is used as the amount of heat representing the amount of heat applied to the catalyst device 3. However, since the amount of heat generated by the internal combustion engine 1 slightly changes depending on the ignition timing of the internal combustion engine 1, if it is necessary to further improve the accuracy of the heat amount data representing the amount of heat applied to the catalyst device 3, the instantaneous (control) The calorific value data may be obtained by correcting the estimated value or the detected value of the intake air amount (for each cycle) according to the ignition timing at each time, and integrating the corrected values. When it is necessary to change the air-fuel ratio of the air-fuel mixture, the estimated value or the detected value of the intake air amount instantaneously (for each control cycle) is determined in the same manner as in the correction according to the ignition timing. The calorific value data may be obtained by correcting according to the air-fuel ratio and integrating the corrected values. In any case, it is possible to cope by preparing a data table or the like in which a correction coefficient for performing correction according to the ignition timing and the air-fuel ratio is set in advance.

Note that the above-described correction when obtaining the calorific value data representing the calorific value given to the catalyst device can be similarly applied when other parameters such as the fuel supply amount are used as the calorific value data.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a control system for an internal combustion engine including an embodiment of the present invention.

FIG. 2 is a diagram schematically showing an intake system of an internal combustion engine of the system of FIG. 1;

FIG. 3 is a diagram for explaining a basic operation of the system of FIG. 1;

FIG. 4 is a flowchart for explaining the operation of the system of FIG. 1;

FIG. 5 is a flowchart for explaining the operation of the system of FIG. 1;

FIG. 6 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 7 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 8 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 9 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 10 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 11 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 12 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 13 is a diagram for explaining the operation of the system in FIG. 1;

FIG. 14 is a flowchart for explaining the operation of the system of FIG. 1;

FIG. 15 is a flowchart for explaining the operation of the system in FIG. 1;

FIG. 16 is a flowchart for explaining the operation of the system in FIG. 1;

FIG. 17 is a flowchart for explaining the operation of the system of FIG. 1;

FIG. 18 is a flowchart for explaining the operation of the system in FIG. 1;

FIG. 19 is a diagram for explaining the operation of the system in FIG. 1;

FIG. 20 is a diagram for explaining the operation of the system of FIG. 1;

FIG. 21 is a diagram for explaining the operation of the system in FIG. 1;

FIG. 22 is a flowchart for explaining the operation of the system in FIG. 1;

FIG. 23 is a flowchart for explaining the operation of the system in FIG. 1;

FIG. 24 is a flowchart for explaining the operation of the system in FIG. 1;

FIG. 25 is a diagram for explaining the operation of the system in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 3 ... Catalyst device, 7 ... Bypass valve (flow control valve), 8 ... Bypass passage (intake air passage), 25 ... Intake air amount operation means, 26 ... Ignition timing operation means.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 43/00 301 F02D 43/00 301L 45/00 312 45/00 312P F02P 5/15 G05B 11/36 505A G05B 11/36 505 F02P 5/15 EC (72) Inventor Tadashi Sato 1-4-1, Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Yoshihisa Iwaki 1, Chuo, Wako, Saitama Prefecture No.4-1 Inside Honda R & D Co., Ltd. (72) Inventor Shusuke Akasaki 1-4-1, Chuo, Wako-shi, Saitama F-term inside Honda R & D Co., Ltd. 3G022 BA01 CA02 CA03 DA01 DA02 DA04 DA10 EA00 FA03 FA04 FA05 FA08 GA00 GA02 GA05 GA06 GA07 GA08 GA09 GA11 GA12 GA20 3G084 BA03 BA04 BA06 BA17 CA02 CA03 DA00 EB12 EC02 EC03 FA01 FA02 FA33 FA38 3G301 HA01 JA20 JA21 KA05 KA07 LA03 LA04 NA03 NA04 NA06 NA08 NB02 NB06 NB11 NC02 ND01 ND05 ND25 ND42 ND45 NE01 NE03 NE17 NE19 NE23 PA01Z PA07Z PA09Z PA10Z PA11Z PA18Z PB03Z PD12Z PE01ZPE01Z04 PE01ZPE01Z04 JA10 JB04 JB18 KA31 KA74 KB33 KC26 KD63 LA18 MA04 MA17

Claims (2)

[Claims] An internal combustion engine that discharges exhaust gas through a catalyst device during idling operation after startup so that the intake air amount of the internal combustion engine is increased by a predetermined amount compared to that during normal idling operation. Intake air amount operation means for operating the opening of the flow control valve provided in the passage; and ignition timing of the internal combustion engine such that the rotation speed of the internal combustion engine converges to a predetermined target rotation speed during the increase of the intake air amount. Operating by feedback control, and an ignition timing operating means for correcting the ignition timing to the retard side, wherein the opening degree of the flow control valve when the intake air amount is increased, A control device for an internal combustion engine, comprising: means for adjusting the intake air amount according to the atmospheric pressure so that the degree of opening increases as the atmospheric pressure decreases. And means for adjusting the opening of the flow control valve when the amount of intake air is increased in accordance with the air temperature so that the opening increases as the air temperature increases. 2. The control device for an internal combustion engine according to claim 1, wherein the control device is provided in an operation means.