JP3064606B2 - Engine ISC valve control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for accelerating or decelerating,
The present invention relates to an ISC valve control method for an engine that controls an intake air flow rate when a throttle valve is rapidly closed after an air blow to improve exhaust emission and prevent engine stall.

[0002]

2. Description of the Related Art When accelerating or decelerating, or when the throttle valve is rapidly closed after blowing, the pressure of the intake pipe rapidly decreases, and the adhered fuel adhering to the inner wall surfaces of the intake port and the intake manifold is removed. The air-fuel ratio is sucked into the combustion chamber at once, and the intake air amount is reduced due to the rapid closing of the throttle valve, thereby causing an over-rich air-fuel ratio, causing misfiring and abnormal combustion due to the over-rich, resulting in deterioration of exhaust emission, An engine stall occurs due to a sudden decrease in the amount of intake air.

In order to prevent such deterioration of exhaust emission and sudden engine stop when the throttle valve is suddenly closed,
In an electronically controlled engine, for example, Japanese Patent Application Laid-Open No. 61-104
As shown in JP 132, when the throttle valve is opened,
Set the ISC (idle speed control) valve interposed in the air bypass passage that bypasses the throttle valve to the set maximum opening, and after shifting to the throttle valve fully closed,
By controlling the opening degree of the ISC valve at a constant decreasing rate, the bypass intake air amount by the ISC valve is sequentially reduced, or, as disclosed in Japanese Patent Application Laid-Open No. Sho 62-178741, the opening degree of the ISC valve is controlled when the throttle is opened. After the throttle valve is fully closed, the decrease rate is set in accordance with the bypass air amount immediately after the throttle valve is fully closed, and the ISC valve is controlled to decrease the opening at this decrease rate to bypass intake by the ISC valve. A dashpot correction is adopted, which gradually reduces the intake air amount and buffers the decrease in intake pipe pressure.

[0004]

However, in the former example, when the throttle is opened, the ISC valve is set to the set maximum opening regardless of the throttle valve opening, and after the throttle is fully closed, the ISC valve decreases at a constant decreasing rate. Therefore, when the throttle is suddenly closed from a state where the throttle opening is relatively small, the dashpot correction period becomes unnecessarily long, and the feeling deteriorates. In the latter prior example, when the throttle valve is opened, the ISC valve opening is increased, and after the throttle valve is fully closed, the decrease rate is set according to the initial bypass air amount immediately after the throttle valve is fully closed. In addition, since the reduction is uniquely controlled in accordance with the reduction rate set by the initial bypass air amount, an appropriate dashpot period cannot always be obtained.

[0005] In both prior arts, since the reduction control is performed at a unique reduction rate after shifting to the idling fully closed state, especially when the throttle valve is suddenly closed and the operation shifts to the idling operation, the return to the idle target rotation speed is performed. If the reduction rate is set to a large value in consideration of the above, the convergence to the idle target speed is deteriorated, and if the reduction rate is set to a small value, the return to the idle target speed is delayed, and the return of the idle target speed is reduced. And convergence cannot be achieved at the same time, resulting in poor controllability.

[0006] Furthermore, after shifting the transmission to a parking range (P range) or a neutral range (N range), there is no load operation when the throttle valve is suddenly closed after blowing or during racing, and the transmission is driven. When the throttle valve is suddenly closed during acceleration / deceleration (load operation) when shifting to a range (first speed range, second speed range, third speed range, drive range, etc.), the rotation drop in no-load operation is more than the load. Since the speed is faster than the rotation drop during operation, control of the ISC valve at a unique reduction rate deteriorates controllability.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to improve exhaust emission at the time of acceleration / deceleration or sudden closing of a throttle valve after idling, and to prevent engine stall. An object of the present invention is to provide an ISC valve control method for an engine capable of shortening a return time to an idle target rotation speed and improving convergence.

[0008] The second object is, in addition to the first object,
An object of the present invention is to provide an ISC valve control method for an engine with improved controllability and excellent feeling regardless of the shift state of the transmission.

[0009]

To achieve the above first object, according to an aspect of, the invention of claim 1, wherein the throttle valve full
When closed, compare engine speed with idle target speed
Depending on the result, the air valve bypassing the throttle valve
The control amount for the ISC valve interposed in the
Feedback control, when the throttle valve is open,
Open loop control and proportional to throttle opening
To set the acceleration / deceleration correction value.
When shifting from fully closed to fully closed, the acceleration / deceleration correction value is gradually increased by the set value.
And then set at least based on engine temperature.
The set basic characteristic value is corrected by the acceleration / deceleration correction value to obtain I
Engine ISC to set control amount for SC valve
In the valve control method, make sure that the throttle valve is fully closed or open.
The procedure for determining whether the valve is a valve and the throttle valve
Set the acceleration / deceleration correction value in proportion to the
The acceleration / deceleration correction value set this time and the acceleration / deceleration correction set previously
Value, and the acceleration / deceleration correction value set this time is
If the acceleration / deceleration correction value is equal to or greater than the
Set as the deceleration correction value, and the current acceleration / deceleration correction value
If it is smaller than the specified acceleration / deceleration correction value,
Acceleration / deceleration correction by subtracting a preset weight loss value from the speed correction value
The procedure for setting the value and the operation when the throttle valve is fully closed
Offset to target idle speed set according to status
Comparison of the judgment threshold value with the added value and the engine speed
If the engine speed is higher than the judgment threshold,
The above acceleration / deceleration correction value is set by the first set value until the value is reached.
It gradually decreases, and the engine speed
When the value falls below the above, the first
Gradually with a second set value smaller than the set value of
The procedure for decreasing the acceleration and deceleration
In the meantime, perform open loop control and at least
The above acceleration / deceleration correction value is added to the basic characteristic value set based on the temperature.
Is added to set the control amount for the ISC valve.
Feedback at least when the acceleration / deceleration correction value becomes zero
And a procedure for shifting to control.

According to a second aspect of the present invention, a throttle valve is provided.
When fully closed, the engine speed and idle target speed
According to the comparison result, the throttle valve bypass
Control of the ISC valve interposed in the bypass passage
When the throttle valve is opened, the amount is feedback controlled.
Performs open loop control and the throttle valve opens
Dashpot correction value is initialized when shifting from
The dashpot correction value by the set value.
And then set at least based on engine temperature.
The specified basic characteristic value is supplemented by the above dashpot correction value.
An engine that sets the control amount for the ISC valve
In the ISC valve control method of
Procedure for determining whether the valve is fully closed or open, and opening the throttle valve
At times, a procedure for setting the dashpot correction value to zero,
When the throttle valve is fully closed,
Discrimination speed set to a value higher than the idle speed
Compare engine speed with engine speed to determine engine speed
When the engine speed drops below the
Initially set the dashpot correction value according to the
Until the rotation speed reduction speed falls below the preset value
During the interval, the dash
The procedure for step-by-step setting of the
When the rotational speed reduction speed falls below the set value,
The set correction value gradually to zero until it reaches zero.
When the dashpot correction value becomes zero,
Until that time, open loop control is performed and at least
The basic characteristic value set based on the engine temperature
Control of ISC valve by adding Schpot correction value
Set the amount and make sure that at least the dashpot correction value is zero.
A procedure to shift to feedback control when
It is characterized by having.

[0011] To achieve the second object, according to claim 3
The invention described in claim 1 is the automatic transmission according to claim 1.
The aircraft is shifted to the P, N range or
Further provided with a procedure for determining whether the
In the range, the above-mentioned off
Set the set value to a high value and set the throttle valve
The above adjustment set in proportion to the throttle opening when the valve is opened
The speed correction value, the weight loss value, and the first set value are increased.
It is characterized in that it is set to a value.

[0012]

According to the first aspect of the present invention, the throttle valve is completely
Determine whether the valve is closed or open. And open the throttle valve
Time, the acceleration / deceleration correction value is proportional to the throttle valve opening.
Set the acceleration / deceleration correction value set this time and the acceleration / deceleration set last time.
Compared with the speed correction value, the acceleration / deceleration correction value
If the acceleration / deceleration correction value is equal to or greater than the specified acceleration / deceleration correction value,
Set the value as the acceleration / deceleration correction value. Also, this acceleration / deceleration
When the correction value is smaller than the previously set acceleration / deceleration correction value
Is the pre-set weight loss value from the previously set acceleration / deceleration correction value.
Subtract and set the acceleration / deceleration correction value. On the other hand, the throttle bar
When the lube is fully closed, the idle target set according to the operating conditions
Judgment threshold and engine that add offset value to rotation speed
And the rotation speed. And the engine speed is determined
If the value exceeds the threshold, the above acceleration /
The correction value is gradually reduced by the first set value. That
Later, the engine speed falls below the judgment threshold due to a decrease in engine speed.
The first setting until the acceleration / deceleration correction value becomes zero.
Gradually reduced by a second set value that is less than the value
You. Until the acceleration / deceleration correction value becomes zero,
Perform open loop control and determine at least
The acceleration / deceleration correction value is added to the basic characteristic value set based on
Set the control amount for the SC valve. And less
Feedback when the acceleration / deceleration correction value becomes zero
Transfer to control.

According to a second aspect of the present invention, there is provided a throttle valve.
Is fully closed or open, and when the throttle valve is open,
Set the dashpot correction value to zero. Also, the slot
When the throttle valve is fully closed, the
The discrimination speed set to a value higher than the idle speed and the
Engine speed and the engine speed is determined.
When the engine speed drops below
Initialize the dashpot correction value. And engine
Until the rotation speed reduction speed falls below the preset value.
In the meantime, the dash
And the step correction value is gradually reduced. Then above
When the engine speed falls below the set value,
The Schpot correction value is gradually reduced by the set small value until it reaches zero.
Next, decrease. And the dashpot correction value is zero.
Open loop control is performed until
Above the basic characteristic value set based on the engine temperature
Add the dashpot correction value to the ISC valve
Set the control amount. And at least the dash
When the correction value becomes zero,
Run.

When setting the acceleration / deceleration correction value,
As in the invention described in claim 3, in the P and N ranges,
Set the above offset value to a higher value than in the driving range.
Set the throttle when opening the throttle valve.
The acceleration / deceleration correction value set in proportion to the opening, and the reduction
Value and the first setting value may be set to a large value.
desirable.

[0015]

[0016]

[0017]

[0018]

Thereafter, the basic characteristic value set based on at least the engine temperature is corrected with the dashpot correction value to set the opening of the ISC valve interposed in the air bypass passage that bypasses the throttle valve.

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are flowcharts showing an ISC valve control procedure.
4 is a flowchart showing a correction value setting procedure, FIG. 4 is a flowchart showing a basic characteristic value setting procedure, FIG. 5 is a flowchart showing an idle target rotational speed setting procedure, FIG. 6 is a flowchart showing a closed / open loop control determination procedure, and FIG. 8 is a flowchart showing an air conditioner correction value setting procedure, FIG. 9 is a flowchart showing an air conditioner correction learning procedure when the air conditioner switch is turned on, and FIG. 10 is a flowchart showing an air conditioner correction learning procedure when the air conditioner switch is turned on. 11 and 12 are flowcharts showing an AT vehicle traveling range correction value setting procedure, and FIGS. 13 and 14 are flowcharts showing an acceleration / deceleration correction setting procedure.
5 is a flowchart showing a dashpot correction value setting procedure, FIG. 16 is a flowchart showing a dashpot correction value updating procedure, FIG. 17 is a flowchart showing a radiant fan correction setting procedure, and FIGS. 18 and 19 are flowcharts showing a power steering correction value setting procedure. 20, FIG. 20 is a flowchart showing a procedure for setting an air conditioner clutch correction value, FIG. 21 is a flowchart showing a procedure for setting a post-start correction initial value, FIG. 22 is a flowchart showing a procedure for setting a post-start correction, and FIGS.
Is a flowchart showing a closed loop correction I minute updating procedure, FIG. 26 is a flowchart showing a closed loop correction I minute learning procedure, FIG. 27 is a schematic diagram of an engine control system,
FIG. 28 is a block diagram of the control device, FIG. 29 is a time chart showing the relationship between the air conditioner switch, the air conditioner correction value and the engine speed, and FIG. 30 is the running range or N, P range, AT vehicle running range correction and engine speed. FIG. 31 is a time chart showing the relationship between the idle switch, the throttle opening, the acceleration / deceleration correction, and the engine speed, and FIG. 32 is a diagram showing the relationship between the idle switch, the engine speed, and the dashpot correction value. 33 is a time chart showing the relationship between the radiator fan ON / OFF and the radiator correction, FIG. 34 is a time chart showing the hysteresis when setting the idling speed, and FIG. 35 is a power steering switch and a power steering correction value. Chart showing the relationship between the engine speed and the engine speed, FIG.
6 is a time chart showing the relationship between the capacity of the air conditioner switch, the air conditioner clutch relay, the air conditioner compressor, the air conditioner clutch correction value, and the engine speed, FIG. 37 is a time chart showing the change in the post-start correction, and FIG. FIG. 39 is a time chart showing the shift of the post-start correction value to the closed loop correction I, FIG. 40 is an explanatory diagram showing the relationship between the correction amount of the closed loop correction I and the differential rotation, and FIG. FIG. 42 is a time chart showing the relationship between the engine speed, the correction amount for the closed loop correction I, and the closed loop correction I, and FIG. 42 is a time chart showing the use status of the learning value for the closed loop correction I.

[Structure of Engine Control System] In FIG. 27, reference numeral 1 in the figure denotes an engine body, and in the figure, a six-cylinder horizontally opposed engine is shown. This engine body 1
The cylinder block 2 is divided into two banks (the right bank in the figure is a left bank and the left bank is a right bank) about the crankshaft 1a.
Cylinder groups of # 3 and # 5 cylinders are arranged, and # 2 and #
A group of four and six cylinders is arranged.

Each cylinder head 3 of each bank has
Each intake port 4 is formed, and each intake port 4 communicates with an intake manifold 5. Upstream of the intake manifold 5, resonance tubes 6a and 6b are connected to correspond to the respective banks, and a variable intake valve 11c is interposed in a passage 6c connecting the resonance tubes 6a and 6b. The resonance tubes 6a and 6b, the passage 6c, and
The variable intake valve 11c constitutes a variable resonance supercharging system.

Further, the upstream of each of the resonance pipes 6a and 6b is connected to the surge tank 7 by opening the throttle chambers 11a and 11b.

An intake pipe 8 is provided upstream of the surge tank 7.
Is opened, and an air cleaner 9 is attached. Immediately downstream of the air cleaner 9, an intake air amount sensor (a hot film type air flow meter in the figure) 10 is interposed.

Further, each of the throttle chambers 11a, 11a,
The throttle valve 11d is provided with throttle valves 11d and 11e (so-called twin throttle valves), and one of the throttle valves 11e is provided with a throttle opening sensor 12a and an idle switch 12b for detecting that the throttle valve is fully closed.
Are connected to each other.

Further, the throttle chamber 11a,
An idle speed control (ISC) valve 13 is interposed in an air bypass passage 6e connecting the passage 6d and the surge tank 7 to the downstream side of the throttle valves 11d and 11e of 11b through a passage 6d.

An injector 14 is disposed immediately upstream of each intake port 4 of each cylinder of the intake manifold 5, and the tip of each cylinder of each cylinder head 3 is exposed to the combustion chamber. A spark plug 15 is attached. An ignition coil 15 a is directly attached to a terminal of the ignition plug 15, and is connected to an igniter 16.

The fuel tank 1 is connected to the injector 14.
Fuel is pressure-fed from an in-tank type fuel pump 18 provided in 7 via a fuel filter 19, and the pressure is regulated by a pressure regulator 20.

A cooling water temperature sensor 21 faces a cooling water passage (not shown) formed in the cylinder block 2, and a right bank knock sensor 22 a and a left bank knock sensor 22 A bank knock sensor 22b is attached, and each exhaust port 23 of each cylinder head 3 communicates with each exhaust pipe 24a, 24b provided for each bank.

The exhaust pipes 24a and 24b have a right bank O2 sensor 25a and a left bank O2 sensor 2 respectively.
5b, catalytic converters 26a and 26b are interposed downstream of the O2 sensors 25a and 25b, respectively, and a catalytic converter 27 is interposed at the junction of the downstream of the catalytic converters 26a and 26b. ing.

On the other hand, a crank angle detecting crank rotor 29 and a group cylinder discriminating crank rotor 30 are mounted on a crankshaft 1a of the engine body 1 at a predetermined interval. Further, each of the crank rotors 29, 3
A first crank angle sensor 31 and a second crank angle sensor 32 each composed of an electromagnetic pickup or the like for detecting a projection serving as a detection object are provided on the outer periphery of 0. Further, a cam angle sensor 34 is provided on the outer periphery of the cam rotor 33a axially mounted on the camshaft 33. The cam angle sensor 34 determines the compression top dead center of a specific cylinder, and determines an individual cylinder based on a cam pulse from the cam angle sensor 34 and a group determination pulse from the second crank angle sensor 32.

The crank rotors 29, 30,
A slit may be provided in the outer periphery of the cam rotor 33a instead of the projection.
2. The cam angle sensor 34 is not limited to an electromagnetic sensor such as an electromagnetic pickup, but may be an optical sensor or the like.

[Circuit Configuration of Control Unit] On the other hand, in FIG. 28, reference numeral 40 denotes a control unit (ECU) comprising a microcomputer. The ECU 40 includes a main computer 41 for controlling ignition timing and fuel injection, and a knock detection. It is composed of two computers, a dedicated sub-computer 42 for processing.

The constant voltage circuit 4 is provided in the ECU 40.
3 is provided, and a stabilized voltage is supplied from the constant voltage circuit 43 to each unit. The constant voltage circuit 43 is connected to a battery 45 via a relay contact of an ECU relay 44, and a relay coil of the ECU relay 44 is connected to a key switch 46.
Is connected to the battery 45 via the. The fuel pump 18 is connected to the battery 45 via a relay contact of a fuel pump relay 47.

The main computer 41 has a main C
PU48, ROM49, RAM50, backup RA
M50a, timer 51, serial interface (S
CI) 52 and an I / O interface 53 are connected to each other via a bus line 54. A backup voltage is always applied to the backup RAM 50a via the constant voltage circuit 43.

The input ports of the I / O interface 53 include an intake air amount sensor 10, a throttle opening sensor 12a, a cooling water temperature sensor 21, and a right bank O2 sensor 2.
5a, left bank O2 sensor 25b, atmospheric pressure sensor 55,
And the vehicle speed sensor 56 are connected via an A / D converter 57a, and the idle switch 12b,
Second crank angle sensors 31 and 32, cam angle sensor 34
Is connected, and the battery 45 is connected to monitor the battery voltage.

Further, the I / O interface 53
The input ports of the power steering switch 58 for detecting the steering state, the neutral switch 59 for detecting whether the automatic transmission select lever is set to the neutral position, and the parking state for detecting whether the switch is set to the parking position A switch 60 and a starter switch 61 for detecting a start state are connected. An igniter 16 is connected to an output port of the I / O interface 53, and a relay coil of a radiator fan relay 63 for controlling driving of an ISC valve 13, an injector 14, and a radiator fan 62, and a variable capacity air conditioner compressor 64. A relay coil of an air conditioner clutch relay 65 for operating connection / disconnection of the magnet clutch 64a is connected via a drive circuit 57b.

On the other hand, the sub-computer 42
U66, ROM67, RAM68, timer 69, SCI
70 and an I / O interface 71 are connected to each other via a bus line 72.

The input ports of the I / O interface 71 are connected to the first and second crank angle sensors 31 and 3 respectively.
2. While the cam angle sensor 34 is connected, the right bank knock sensor 22a and the left bank knock sensor 22b
Are the amplifier 73, the frequency filter 74, and the A / D
It is connected via a converter 75.

Each of the knock sensors 22a and 22b includes, for example, a vibrator having a natural frequency substantially equal to that of knock vibration,
A resonance type knock sensor composed of a piezoelectric element that detects the vibration acceleration of this vibrator and converts it into an electric signal. It detects vibration transmitted to a cylinder block, etc., due to a combustion pressure wave during the explosion stroke of the engine, and detects the vibration. The waveform is output as a knock signal.

After the knock signal is amplified to a predetermined level by the amplifier 73, necessary frequency components are extracted by the frequency filter 74 and converted from analog data to digital data by the A / D converter 75.

The main computer 41 and the sub-computer 42 are connected by a serial line via SCIs 52 and 70, and the output port of the I / O interface 71 of the sub-computer 42 is connected to the main computer 41. It is connected to the input port of the I / O interface 53.

The main computer 41 calculates the ignition timing and the like based on the crank pulse, and when a predetermined ignition timing is reached, outputs an ignition signal to the corresponding cylinder.
The sub-computer 42 calculates the engine speed from the input interval of the crank pulse, and based on the engine speed and the engine load, the knock sensors 22a, 22
A sample period of the knock signal from 2b is set, and in this sample period, the knock signal from each of the knock sensors 22a and 22b is A / D-converted at a high speed, and the vibration waveform is faithfully converted into digital data. Is determined.

The result of the determination as to whether or not knock has occurred is output to the I / O interface 71 of the sub-computer 42. If knock has occurred, the sub-computer 42 sends the main computer 41 through the serial line via the SCI 70 and 52. The main computer 41 immediately delays the ignition timing of the corresponding cylinder based on the knock data to avoid knocking.

Reference numeral 81 denotes an air conditioner control unit, which is connected to a CPU 82, a ROM 83, a RAM 84, and an I / O interface 85 via a bus line 86.
A stabilized voltage is supplied to each unit from a constant voltage circuit 88 connected to the battery 45 via an ignition switch 87.

An input port of the I / O interface 85 is connected to an air conditioner switch 89 and an I / O interface 53 of the main computer 41. The main computer 41 sends the variable capacity air conditioner to the air conditioner control unit 81. Compressor 64
DUTY signal is output.

The output port of the I / O interface 85 is connected to the variable capacity air conditioner compressor 6.
4 is connected to a variable capacity control valve (not shown) to output a capacity (DUTY) signal, and is connected to an input port of the I / O interface 53 of the main computer 41, and the air conditioner switch 89 is turned on. A signal indicating whether or not the operation has been performed is output.

[Operation] Next, I of the embodiment having the above configuration will be described.
The control operation of the SC valve 13 will be described.

(ISC Valve Control Main Routine) FIGS. 1 and 2 show a main routine showing an ISC valve control procedure executed by the main computer 41, which is executed at a predetermined calculation cycle.

First, step (hereinafter abbreviated as “S”) 101
The battery voltage correction value ISCVB is set based on the monitored battery voltage. If the battery voltage is low, the ISC valve 13 does not reach the predetermined opening, so the battery voltage correction value ISCVB is set to a larger value as the battery voltage is lower.

At step S102, an atmospheric pressure correction coefficient KALT is set. Since the intake air flow rate becomes relatively low when the atmospheric pressure is low, the atmospheric pressure correction coefficient KALT is set to a larger value as the atmospheric pressure is lower.

Thereafter, when the operation proceeds to S103, it is determined whether or not the starter switch 61 is ON in order to make a start determination. When the starter switch 61 is ON, it is determined that the engine is being started, and the operation proceeds to S104. When it is OFF, it is determined that the engine is stopped or the engine is operating. To S105.

In S105, it is determined whether the engine is stopped based on the engine speed NE detected by the output of the first crank angle sensor 31. If NE = 0 (engine stopped), S1 is executed.
Proceed to 04 and proceed to S114 if NE ≠ 0 (engine running).

If it is determined in S103 or S105 that the engine is being started or the engine is being stopped, the process proceeds to S104, where a start-time control process is executed.

In S104, the starting characteristic value table TIS based on the cooling water temperature TW detected by the cooling water temperature sensor 21.
Starting characteristic value ISCST by referring to CST with interpolation calculation
Set.

Then, the process proceeds to S106, where the starting characteristic value I
The value obtained by adding SCST and the battery voltage correction value ISCVB is multiplied by the atmospheric pressure correction coefficient KALT to obtain an ISC valve 13.
Is set (ISCON ← (ISCST + ISCVB) × KALT).

Thereafter, in S107, a post-start elapsed time determination count value COUNT for determining whether or not the elapsed time after engine startup has reached a set time TMASI [SEC] used in a closed / open loop control determination subroutine described later.
A set value COUNTTMASI corresponding to the set time TMASI is set in ST (down counter) (COUNTST ← COU
NTTMASI), and then proceeds to S108, in which a start-up / normal control discrimination flag FLAGST used for setting a post-start correction ISCSD and a closed-loop correction I minute ISCI described later is set.
After setting (FLAGST ← 1) to indicate that the start-time control is being executed, the process proceeds to S109.

In step S109, the duty ratio ISCON is compared with the lower limit value IMINOP during open loop control, and
If SCON ≦ IMINOP, set duty ratio IS
Since CON is equal to or lower than the lower limit, the duty ratio ISCON is set at the lower limit IMINOP in S110 (ISCON
← IMINOP), and proceed to S138.

On the other hand, in S109, ISCON> IMINOP
In step S111, the process proceeds to step S111, where the upper limit value IMAXOP is set by referring to the upper limit value table TBMXOP based on the cooling water temperature TW. The upper limit value table TMXOP stores a high upper limit value IMAXOP because the startability becomes more difficult if the cooling water temperature TW is low.

Then, in S112, the duty ratio ISCON
Is compared with the upper limit value IMAXOP, and ISCON ≧ IMAXOP
In step S113, the process proceeds to step S113, where the duty ratio ISCON is fixed at the upper limit value IMAXOP (ISCON ← IMAXOP), and the process proceeds to step S138. If ISCON <IMAXOP, the process proceeds directly to S138.

On the other hand, if it is determined in S105 that NEＮ0 (the engine is operating), the process proceeds to S114, and the normal control process is executed.

In S114, the start / normal control discrimination flag FLAGST is cleared (FLAGST ← 0, normal control), and in S115, the basic characteristic value setting subroutine (details will be described later) is executed to execute the basic characteristic value subroutine. Set the value ISCTW and S1
At step 16, an idle target rotation speed setting subroutine (to be described in detail later) is executed to set an idle target rotation speed NSET, and S
After executing the closed / open loop control determination subroutine (details will be described later) in 117 to determine whether the control is closed loop control or open loop control, the process proceeds to S118. S1
At 18, the air conditioner correction value ISCAC set in the correction value setting routine (interrupt execution every 51.2 msec) described later is read, and in S119, the AT vehicle travel range correction value ISCATDS set in the correction value setting routine is used in the main routine. Set the gear position correction value ISCAT to be used (ISCAT ← I
SCATDS), and the final acceleration / deceleration correction value I is calculated based on the acceleration / deceleration correction value DSHPT set in the correction value setting routine in S120.
The SCTR is set (ISCTR ← DSHPT), and the post-start correction value ICASS is set in S121 by the post-start correction ISCSD set in each interrupt routine to be described later (ISCAS ← ISCS).
D), the dashpot correction value DHENB updated in the correction value setting routine in S122 is read out, and the closed loop correction I minute ISCI set in the closed loop correction I minute update procedure (interrupt execution every 10 msec) described later in S123. The closed loop correction value ISCCL used in the main routine is set (ISCCL ← ISCI).

Then, the radian correction value ISCRA used in the main routine is set by the radiant fan correction ISCRAS set in the correction value setting routine in S124 (ISCRA ← ISCRAS), and in S125, the radian correction value ISCRAS is set in the correction value setting routine. The set power steering correction value ISCPS is read, and in S126, the air conditioner clutch correction value ISCCLH set in the correction value setting routine is read.

Thereafter, in S127, the basic characteristic value ISCTW,
Air conditioner correction value ISCAC, gear position correction value ISCAT, acceleration / deceleration correction value ISCTR, post-start correction value ISCAS, dashpot correction value DHENB, closed loop correction value IS
CCL, Radifan correction value ISCRA, Power steering correction value IS
The atmospheric pressure correction coefficient KALT is added to the sum of CPS, air conditioner clutch correction value ISCCLH, and battery voltage correction value ISCVB.
And the duty ratio ISCON is set as shown in the following equation.

ISCON ← (ISCTW + ISCAC + ISC
AT + ISCTR + ISCAS + DHENB + ISCCL + IS
CRA + ISCPS + ISCCLH + ISCVB) × KALT A closed / open loop control discrimination flag F which is set to 1 when closed loop control is selected in S128.
Referring to the value of LAGCL, if FLAGCL = 1 and closed loop control is selected, the process proceeds to S129, and FLAGCL
If the open loop control is selected at = 0, the process returns to S109 to execute the same duty limitation as at the start.

At step S129, the duty ratio ISCON
Is compared with the lower limit value IMINCL at the time of the closed loop control. If ISCON ≦ IMINCL, the routine proceeds to S130, where the duty ratio ISCON is set to the lower limit value IMINCL (ICONL).
SCON ← IMINCL), and proceeds to S138. The lower limit value IMI
In the case of NCL or IMINOP, the duty ratio ISCON is unnecessarily reduced and the opening of the ISC valve 13 is reduced, and
This is set to prevent the feeling from deteriorating and the engine stall due to a decrease in the idle speed due to a decrease in the air flow rate by the C valve 13.

On the other hand, when it is determined in S129 that ISCON> IMINCL and the routine proceeds to S131, the upper limit basic value IMAX is set by referring to the table TBMXCL with interpolation calculation based on the cooling water temperature TW. This upper limit basic value IMAX is the duty ratio ISC
This setting is made to prevent the ON speed from becoming unnecessarily large and the idling speed from becoming excessive. On the table, the higher the cooling water temperature TW, the lower the basic characteristic value ISCTW, and therefore, the duty ratio ISCON Therefore, the upper limit basic value IMAX is stored as the cooling water temperature TW becomes higher.

Then, the process proceeds to S132, where the air conditioner switch 8
9 is ON, and if it is ON, the process proceeds to S133, and the upper limit basic value air conditioner correction ID1 is set to the set value ISCBAC (ID1
← ISCBAC), and in the case of the OFF state, proceed to S134, and set the upper limit basic value air conditioner correction ID1 to 0 (ID1 ← 0).

Then, in S135, the upper limit basic value IMAX is added to the upper limit basic value air conditioner correction ID1 to set an upper limit value IMAXCL (IMAXCL ← IMAX + ID1). The upper limit value IMAXC because the air conditioner is idle when it is running
L is also set higher by the air conditioner correction value ID1.

Then, in S136, the duty ratio ISCON
And the above upper limit value IMAXCL, ISCON ≧ IMAXCL
In the case of, the process proceeds to S137 and the duty ratio ISCON is set to the upper limit value I.
MAXCL is set (ISCON ← IMAXCL), and the process proceeds to S138. If ISCON <IMAXCL, the duty ratio I
SCON is within the allowable range (IMINCL <ISC
ON <IMAXCL), and the process directly proceeds to S138.

Thereafter, when the process proceeds from S110, S113, S130, S136 or S137 to S138, the duty signal DUT corresponding to the duty ratio ISCON set in each of the above steps is obtained.
Y is output to the coil of the ISC valve 13 (DUTY ←
ISCON), exit the routine.

The output of the duty signal DUTY for the ISC valve 13 is held until a new duty signal DUTY is set at the next execution of the routine. (Correction Value Setting Routine) FIG.
This is a correction value setting routine that is executed by interruption every msec.

First, an air conditioner correction value setting subroutine (details will be described later) is executed in S201 to execute an air conditioner correction value ISCAC.
The AT vehicle running range correction value setting subroutine (to be described later) is executed in S202 to set the AT vehicle running range correction value ISCATDS, and the acceleration / deceleration correction value setting subroutine (details described later) is executed in S203. Acceleration / deceleration correction value DSH
The PT is set, the dashpot correction value update subroutine (details will be described later) is executed in S204 to update the dashpot correction value DHENB, and the radifan correction setting subroutine (details described later) is executed in S205 to execute the radifan correction ISC.
The RAS is set, the power steering correction value setting subroutine (details will be described later) is executed in S206 to set the power steering correction value ISCPS, and the air conditioner clutch correction value setting subroutine (details described later) is executed in S207. IS
Set CCLH and exit the routine.

(Basic characteristic value setting subroutine) FIG. 4 is a basic characteristic value ISCTW setting subroutine executed in the main routine (see S115).
Are set separately for warm-up (parked state) and running warm-up.

First, it is determined whether the vehicle is completely stopped in S301 to S303. In S301, the idle switch 12b is turned on
If it is ON (throttle valves 11d and 11e are fully closed), the process proceeds to S302, and OFF (throttle valve 1
If 1d and 11e are open), the process proceeds to S305.

In S302, the parking switch 60 is turned on.
(The state where the select lever is set to the P range)
In the case of, the process proceeds to S303, and in the case of OFF, the process proceeds to S305.

In S303, the vehicle speed V detected by the vehicle speed sensor 56
It is determined whether the vehicle speed VSP is 0 based on SP, and VSP = 0.
In the case of (stop state), the process proceeds to S304, and in the case of VSP ≠ 0 (running state), the process proceeds to S305.

In step S304, a leaving / running warm-up discrimination flag FLAGTIS is set (FLAGTIS ← 1, leaving warm-up), and in step S306, the basic warm-up warming characteristic value table TISTWS is referred to with interpolation calculation based on the cooling water temperature TW. After setting the basic characteristic value ISCTW, the routine exits.

Since the transmission is shifted to the P range and the vehicle is completely stopped, the opening characteristic of the ISC valve 13 is increased and the basic characteristic value ISCTW of the warming-up is taken by the ISC valve 13. The value is set higher than the running warm-up in order to increase the air amount, increase the engine speed, and shorten the engine warm-up completion time. Although there is an upper limit in consideration of the fuel consumption rate and feeling, the optimum basic characteristic value ISCTW is obtained from experiments and the like and the table is obtained by obtaining the cooling water temperature TW as a parameter.
Store in.

On the other hand, S301, S302, or S303 to S305
In step S307, the flag for leaving / running warm-up flag FLAGTIS is cleared (FLAGTIS ← 0, running warm-up), and in S307, the running warm-up basic characteristic value table TISTWR based on the cooling water temperature TW.
Is set with the interpolation calculation to set the basic characteristic value ISCTW, and then the routine exits.

When the transmission is in the D range (first speed, 2nd speed)
Speed) and the range has been shifted to the N range. In order to prevent discomfort during accelerator depression and running, the optimum basic characteristic value ISCTW during running warm-up is obtained by experiments using the cooling water temperature TW as a parameter and stored in the ROM 49. It is stored in a table and set to a lower value than the warm-up time.

(Idle target speed setting subroutine)
FIG. 5 is a subroutine for setting the idle target rotation speed NSET executed in the main routine (see S116).

First, in step S401, the idle / running warm-up discrimination flag F
With reference to the value of LAGTIS, if FLAGTIS = 1 (warm-up during standing), proceed to S402, FLAGTIS = 0 (warm-up during running).
In the case of, go to S403.

In S402, the target warm-up rotation speed NSETS is set by referring to the target warm-up rotation speed table TNSETS with interpolation calculation based on the cooling water temperature TW.
After setting the idle target rotation speed NSET stored at a predetermined address in the RAM 50 with the target rotation speed during idle warming NSETS (NSET ← NSETS), the flow proceeds to S406.

The target rotation speed table TNS at the time of the warm-up during the leaving as described above.
The ETS is stored in the ROM 49, and in each area, an optimum target rotation speed NSETS obtained in advance through experiments or the like is stored. During the warm-up period, the transmission is shifted to the P range, and the vehicle is completely stopped. Therefore, in order to reduce the warm-up time, the target rotation speed NSE of each region is reduced.
TS is set to a value higher than a target rotation speed NSETR during traveling warm-up described later.

On the other hand, in step S401, the travel warm-up (FLAGTIS
= 0), and proceeds to S403, based on the coolant temperature TW, refers to the target rotational speed table TNSETR at the time of traveling warm-up with interpolation calculation, sets the target rotational speed NSETR at the time of traveling warm-up, and proceeds to S405. After setting the idle target rotation speed NSET stored at a predetermined address in the RAM 50 to the target rotation speed NSETR at the time of traveling warm-up (NSET ← NSTR), the process proceeds to S406.

The target rotation speed table TNS at the time of running warm-up described above.
The ETR is stored in the ROM 49 and is obtained by calculating the target rotation speed NSETR using the cooling water temperature TW as a parameter, and is set to a value lower than that of the warm-up.

When the process proceeds from S404 or S405 to S406, it is determined whether the neutral switch 59 is OFF (the select lever is set to a position other than the N range).
Proceeding to S407, if the power is ON, the power is not transmitted to the transmission and the load on the engine 1 is not applied, so the process proceeds to S409.

When the operation proceeds to S407, the parking switch 6
0 is OFF (select lever is set other than P range)
The selector lever is in the D range,
It is determined that the engine has been shifted to the first, second, etc. drive ranges and the engine is under load, and the program proceeds to S408, where it is turned on.
In the case of, the select lever has been shifted to the P range,
Since no load is applied to the engine 1, the process proceeds to S409.

When the process proceeds from S407 to S408, the value of the flag for leaving / running warm-up flag FLAGTIS is referred to, and FLAGTIS is referred to.
If = 0 (running warm-up), proceed to S410, FLAGTIS = 1
In the case of (ignition warm-up), jump to S411.

In step S410, since the vehicle is running, the target rotational speed NSET is set to the target rotational speed NSETR set in step S403 to increase the idle target rotational speed NSET by the set value DNAT.
The idle target rotation speed NSET stored at a predetermined address of the RAM 50 is set with the value obtained by adding the AT (NSE
T ← NSETR + DNAT), and proceed to S411.

When the operation proceeds to S411, the air conditioner switch 89 is turned on.
Then, if it is ON, proceed to S412, compare the preset target rotation speed lower limit value DARCON when the traveling range air conditioner is ON with the idle target rotation speed NSET, and set NSET ≦ D
In the case of ARCON, the process proceeds to S413, in which the running range air conditioner ON target speed lower limit value D is a lower limiter for lowering the idle target speed NSET to the air conditioner load.
After setting with ARCON (NSET ← DARCON),
Exit the routine.

Further, in S411, it is determined that the air conditioner switch 89 is OFF, or in S412, NSET> DARCO
If it is determined to be N, the process exits the routine.

On the other hand, when the process proceeds from S406 or S407 to S409, it is determined whether or not the air conditioner switch 89 is ON. Value NARC
ON, and if NSET ≦ NACON, proceed to S415 and set the idle target rotational speed NSET with the N / P range air conditioner ON target rotational speed NARCON, which is the lower limiter to deal with the load when the air conditioner is ON. After performing (NSET ← narcon), the routine exits. Also,
If it is determined in S409 that the air conditioner switch 89 is OFF, or if it is determined in S414 that NSET> NARCON,
Exit the routine.

(Closed / Open Loop Control Determination Subroutine) FIG. 6 is executed in the main routine (S117).
This is a closed / open loop control determination subroutine to be performed.

First, in S501, in order to determine whether or not the set time after start TMASI has elapsed, the count value of the elapsed time after start determination COUNTST is referred to, and when COUNTST = 0,
That is, if it is determined that the set time has elapsed after the start, the process proceeds to S502, and if COUNTST ≠ 0, the process proceeds to S503, and the elapsed time determination count value COUNTST after the start is counted down (C
(OUTSTST ← COUNTST-1), since the set time has not elapsed after the engine is started and the engine speed is still estimated to be unstable, the flow jumps to S527 to select open loop control and close / open loop control discrimination flag Clear FLAGCL and exit the routine.

On the other hand, when the flow proceeds to S502, the idle switch 12
b is ON, and ON (throttle valve 11d,
If 11e is fully closed), the process proceeds to S504, and if OFF (throttle valves 11d and 11e are open), the process jumps to S527 to select open loop control.

When the process proceeds from S502 to S504, it is determined whether the neutral switch 59 is ON.
To determine if the parking switch 60 is ON and ON
In the case of, the process proceeds to S509, and in the case of OFF, the process proceeds to S506.

Neutral switch 5 in S504 and S505
9. Both the parking switch 60 is OFF and the select lever is in a range other than the N range and the P range, that is,
When it is determined that the travel range has been set and the process proceeds to S506, the elapsed time after the neutral switch 59 or the parking switch 60 has been turned ON, that is, after the shift to the P and N ranges has reached the set time ATC [SEC]. Elapsed time determination count value C after shifting to P and N ranges to determine
The set time ATC is set in OUNTAT (down counter).
After setting the set value COUNTATTC corresponding to the following, the routine proceeds to S507, where the vehicle speed VSP detected by the vehicle speed sensor 56 is compared with a preset vehicle speed VSPFBA for discriminating closed / open loop control during running, and if VSP <VSPFBA
Proceed to S508, and if VSP ≧ VSPFBA, proceed to S527 to select open loop control. Then, in S508, the engine speed NE detected based on the output of the first crank angle sensor 31 is compared with a preset closed / open loop control determination speed RPMFB, and NE <RPMFB
If so, proceed to S513; if NE ≧ RPMFB, proceed to S527 to select open loop control.

Further, when it is determined that the range is the N range or the P range and the process proceeds from S504 or S505 to S509, the value of the elapsed time determination count value COUNTAT after shifting to the P and N ranges is referred to. Or N
After shifting to the range, it is determined that the set time ATC [SEC] has elapsed, and the process proceeds to S510.

On the other hand, if it is determined in S509 that COUNTAT ≠ 0, the routine proceeds to S511, where the elapsed time determination count value COUNTAT after shifting to the P, N range is counted down (COUNT).
AT ← COUNTAT-1), after shifting from the driving range to the P and N ranges, it is estimated that the set time has not elapsed, and that the engine speed has not yet been stabilized due to a sudden change in the engine load, and the flow jumps to S527. Select open loop control.

When COUNTAT = 0 is determined in S509 and the routine proceeds to S510, the vehicle speed VSP detected by the vehicle speed sensor 56 is compared with a predetermined vehicle speed VSOPPA for determining closed / open loop control when the vehicle is stopped, and VSP ≧ VSPOPA.
If A, proceed to S512, compare the engine speed NE with a value obtained by adding the set value NCLOP to the idle target speed NSET set in the above-mentioned idle target speed setting subroutine, and go to S513 if NE <NSET + NCLOP. Proceeds, and if NE ≧ NSET + NCLOP, the process jumps to S527 to select ＄ open loop control.

If VSP <VSPOPA in S510, or if NE <(NSET + NCLOP) in S512, the process proceeds to S513, in which the set value DNACF is subtracted from the engine speed NE and the idle target speed NSET. The value is compared with the value, and if NE <(NSET-DNACF), S517
To S514 if NE ≧ (NSET-DNACF)
Proceed to. In S514, it is determined whether or not the air conditioner switch 89 is OFF.
15 、 Elapsed time after turning on and off the air conditioner is set time A
Air conditioner ON to determine whether OFF [SEC] has been reached
→ Set the count value COUNTA (down counter) after the OFF elapsed time determination to the set value COUNTAOFF corresponding to the set time AOFF (COUNTA ← COUNT)
TAOFF), because the air conditioner switch 89 is currently ON and the air conditioner correction is in transition, S5 is executed to execute open loop control.
Jump to 27.

On the other hand, in S514, the air conditioner switch 89 is turned off.
If it is determined to be F and the process proceeds to S516, the air conditioner is turned on → OF
Referring to the value of the post-F elapsed time determination count value COUNTA, if COUNTA = 0, it is determined that the set time AOFF [SEC] after the air conditioner switch 89 has been turned ON → OFF, and the flow proceeds to S517. If COUNTA ≠ 0, the process proceeds to S518, and the elapsed time determination count value C after the air conditioner has been turned on → off C
Count down COUNTA (COUNTA ← COU
NTA-1), and proceed to S527 to select open loop control.

Then, when proceeding from S513 or S516 to S517, the engine speed NE is subtracted from the idle target speed NSET to obtain a differential rotation ΔN. In S519, the differential rotation ΔN and the set value NDPS are calculated. Compare and if ΔN ≧ NDPS
Proceed to S520, and proceed to S527 if ΔN <NDPS.

At S520, the differential rotation ΔN and the set value D
NFB (however, DNFB ≧ NDPS) and ΔN ≦
In the case of DNFB, the process proceeds to S521, and in the case of ΔN> DNFB, it is determined that the closed loop control condition is satisfied, and the process proceeds to S525.

[0113] Proceeding to S521, with reference to the value of the acceleration correction value DSHPT set by the deceleration correction value setting subroutine to be described later, acceleration correction value DSHPT it is determined whether 0 [%], the DSHPT = 0 In this case, proceed to S522, and DSHPT $ 0
If so, proceed to S523.

When the flow advances to S522, the dashpot correction value DH set in a dashpot correction value setting routine described later.
With reference to the value of ENB, the dashpot correction value DHENB
Is determined to be 0 [%], and if DHENB ≠ 0, proceed to S523; if DHENB = 0, proceed to S524.

In S523, the acceleration / deceleration correction value DSHPT = 0,
Alternatively, the steady state shift determination count value COUNTCL (down counter) for determining whether or not the dashpot correction value DHENB = 0 has passed the set time CLSD [sec] is set to the set value CO corresponding to the set time CLSD.
Set UNTCLSD (COUNTCL ← COUNTCLS
D) Since the acceleration / deceleration correction or the dashpot correction is currently being performed, the process proceeds to S527 to select open loop control.

On the other hand, when the process proceeds from S522 to S524, the value of the steady state transition determination count value COUNTCL is referred to, and COU
If NTCL = 0, it is determined that the steady state is satisfied and the closed loop control condition is satisfied, and the process proceeds to S525 to select the closed loop control. If COUNTCL ≠ 0, the process proceeds to S526 to count down the steady state transition determination count value COUNTCL. (COUNTCL ← COUNTCL−1), and proceeds to S527.

Then, when the flow proceeds from S520 or S524 to S525, the closed / open loop control discrimination flag FLAG
CL is set (FLAGCL ← 1, closed loop control is selected), and the routine exits.

Also, S502, S503, S507, S508, S511, S512, S5
15, S518, S519, S523 Alternatively, when the process proceeds from S526 to S527, the closed / open loop control determination flag FLAGCL is cleared (FLAGCL ← 0, open loop control selection).
And exit the routine.

The closed loop control conditions according to the above-mentioned flowchart are summarized as the following <1> to <7>. Otherwise, open loop control is performed.

<1> Predetermined time TMASI [sec] after starting
<2> Idle switch 12b is ON. <3> (i) Neutral switch 59 or parking switch 60 is ON and vehicle speed VSP <VSPOPA.
Or (ii) when neutral switch 59 or parking switch 60 is ON, VSP ≧ VSPOPA [Km / h]
However, the engine speed NE <(NSET + NCLO
P) [rpm] or (iii) the neutral switch 59 or the parking switch 60 are both OFF, and the vehicle speed VSP <V
SPFBA [Km / h] and engine speed NE <RPMFB [r
<4> (i) The air conditioner switch 89 is ON and the air conditioner transient correction value ISCACF = 0 or ISCACF０0
[%], The engine speed NE <(NNSET−DN
ACF) [rpm] or (ii) Air conditioner switch 89 is OFF and ON →
After a lapse of a predetermined time AOFF [sec] after turning off, or when the engine speed NE <(NSET-DNACF) [rpm]. <5> The neutral switch 59 or the parking switch 60 is ON, and it is OFF → ON and predetermined. Time AT
<6> Power steering correction value ISCPS = 0 or ISC
Even if PS ≠ 0 [%], differential rotation ΔN ≧ NDPS [rpm] <7> (i) All of <1> to <6> are satisfied, and acceleration / deceleration correction value DSHPT = 0 [%] ] And dashpot correction
The state in which the value DHENB = 0 [%] is a predetermined time CLSD [sec]
Even if it has continued or the predetermined time CLSD [sec] has not been maintained, the differential rotation ΔN> DNFB [rpm] or (ii) all of <1> to <6> are satisfied and acceleration / deceleration correction is performed. Even when the value DSHPT ≠ 0 [%] or the dashpot correction value DHENB ≠ 0 [%], the differential rotation ΔN> DNFB [r
pm] (Air Conditioner Correction Value Setting Subroutine) FIGS. 7 and 8 are air conditioner correction value ISCAC setting subroutines (see S201) executed in a correction value setting subroutine interrupted every 51.2 msec.

First, in S601, it is determined whether the neutral switch 59 is ON. If it is OFF, the process proceeds to S602. If it is ON, it is determined that the range is the N range, and the process proceeds to S603.

When the flow advances to S602, the parking switch 60 is turned on.
If it is ON, it is determined that it is the P range and the process proceeds to S603. If it is OFF, it is determined that it is the travel range and the process proceeds to S604.

When the flow advances to S603, the traveling range determination flag FLA
Clear GAT (FLAGAT ← 0, N or P range)
Proceed to S605, and when proceeding to S604, set the running range determination flag FLAGAT (FLAGAT ← 1, running range).
Proceed to S605.

In S605, it is determined whether or not the air conditioner switch 89 is ON. If it is ON, the process proceeds to S606, and if it is OFF, S6.
In step 07, the air conditioner transient correction end determination count value COUNTAC (down counter) for determining whether a predetermined time AON [sec] has elapsed since the air conditioner switch 89 was turned on is set to a set value C corresponding to the predetermined time AON.
Set COUNTAON (COUNTAC ← COUNTAON
) And proceed to S620. Air conditioner switch 89 in S605 above
Is determined to be ON and proceeds to S606, referring to the value of the air conditioner transient correction end determination count value COUNTAC, and
If TAC ≠ 0, it is determined that the predetermined time AON has not elapsed since the air conditioner switch was turned off → on, and the process proceeds to S608. If COUNTAC = 0, the air conditioner switch is turned off.
→ It is determined that the predetermined time AON has elapsed after the ON, and the process proceeds to S611.

At S608, the air conditioner transient correction end determination count value COUNTAC is counted down (COU
NTAC ← COUNTAC-1), proceeds to S609, compares the engine speed NE with the value obtained by adding the set value DNAC to the idle target speed NSET, and determines that the engine speed NE is lower than the set speed when NE ≦ NSET + DNAC. Then, the process proceeds to S610, and if NE> NSET + DNAC, it is determined that the engine speed NE is higher than the set speed, and the process proceeds to S611.

When the flow advances to S610, the travel range determination flag FLA
Referring to the value of GAT, if FLAGAT = 1 (running range), proceed to S612, and if FLAGAT = 0 (N or P range), proceed to S613.

When the flow proceeds to S612, the air conditioner transient correction value ISCAC
After setting the initial value of F with the set value ACFFD (ISCAC
F ← ACFFD [%]), and the process proceeds to S616. Further, when the process proceeds to S613, the air conditioner transient correction value ISCACF is set to the set value ACFFN.
After setting the initial value with (ISCACF ← ACFFN
[%]), And proceed to S616.

On the other hand, when the process proceeds from S606 or S609 to S611, it is determined whether the air conditioner transient correction value ISCACF is equal to or less than 0 [%]. ] After setting (I
SCACF ← 0), and proceed to S616. If ISCACF> 0, the set value DAC is calculated from the air conditioner transient correction value ISCACF.
The air conditioner transient correction value ISCACF is the value obtained by subtracting FF.
(ISCACF ← ISCACF-DACF)
F), proceed to S616.

When the process proceeds to S616 from any of the above S612 to S615, the value of the travel range discrimination flag FLAGAT is referred to and FL is determined.
If AGAT = 1 (running range), proceed to S617, FLAG
If AT = 0 (P, N range), proceed to S618.

At S617, the air conditioner steady-state correction value ISCAC
After setting S with the set value ACDTY (ISCACS ← AC
DTY), and the process proceeds to S619. In step S618, the air conditioner steady-state correction value ISCACS is read from a predetermined address in the backup RAM 50a, and the air-conditioner learning correction value MACDTY is read.
(Set in a later-described air conditioner correction learning routine) (ISCACS ← MACDTY), and then the flow proceeds to S619.

When the process proceeds from S617 or S618 to S619,
The air conditioner correction value ISC is a value obtained by adding the air conditioner steady-state correction value ISCACS to the air conditioner transient correction value ISC ACF.
Set AC [%] (ISCAC ← ISCACF + ISCACS)
), Exit the routine.

On the other hand, when the process proceeds from S607 to S620, the air conditioner correction value ISCAC is read and the air conditioner correction value ISCA
It is determined whether CAC is 0% or less, and if ISCAC ≦ 0, S6
Proceed to 21 to set the air conditioner correction value ISCAC to 0 [%] (ISCAC ← 0), and then exit the routine.

If ISCAC> 0, the process proceeds to S622, where the air conditioner correction value ISCAC and the set value ISCACD [%] are set.
(A value close to 0%), and if ISCAC ≧ ISCACD, the process proceeds to S623. If ISCAC <ISCACD, the air conditioner correction value ISCAC is close to 0 [%], thereby preventing control hunting and improving convergence. Therefore, the process proceeds to S624 to reduce the subtraction amount.

When the flow advances to S623, the traveling range determination flag FLA
Referring to the value of GAT, if FLAGAT = 1 (running range), proceed to S626 and set the weight loss value DSAC to the set value DSAC1D.
Set in [%] (DSAC ← DSAC1D), and proceed to S630. When FLAGAT = 0 (P, N range), S6
Then, the process proceeds to step S27, in which the reduced value DSAC is set with the set value DSAC1N (DSAC ← DSAC1N), and the process proceeds to step S630.

When the process proceeds from S622 to S624, the value of the running range determination flag FLAGAT is referred to, and FLAGAT = 1.
In the case of (running range), proceed to S628 and set the reduced value DSAC to the set value DSAC2D (however, DSAC1D> DSAC2D)
(DSAC ← DSAC2D), and the process proceeds to S630. If FLAGAT = 0 (P, N range), the process proceeds to step S629, where the weight loss value DSAC is set to the set value DSAC2N (however, DS
AC1N> DSAC2N) (DSAC ← D
SAC2N), and proceed to S630.

When the process proceeds to S630 from any of S626 to S629, the air conditioner correction value ISCAC is subtracted by the reduced value DSAC (ISCAC ← ISCAC-DSAC), and the routine exits.

FIG. 29 shows a typical example of the above air conditioner correction value setting.
Will be described according to the time chart of FIG.

When the air conditioner switch 89 is set from OFF to ON, the air conditioner correction value ISCAC is set to a preset air conditioner steady-state correction value IS for a predetermined time AON [sec].
CACS (ACDTY or MACDTY) and air conditioner transient correction value ISCACF (ACFFD or A
CFFN) (elapsed time t1 to
t2) During the predetermined time AON [sec], the engine speed NE is controlled so as to approach the engine speed obtained by adding the set value DNAC to the idle target speed NSET.

At this time, if the air conditioner correction value ISCAC is set to a value that does not include the air conditioner transient correction value ISCACF, the load due to the driving of the air conditioner compressor is suddenly applied to the engine immediately after the air conditioner switch 89 is turned on. As shown by the broken line in (c), the engine speed greatly fluctuates, and the feeling deteriorates.

When the predetermined time AON [sec] has elapsed, the air conditioner transient correction value ISCACF is decreased by the set value DACFF in each operation cycle until it becomes 0 (elapsed time t2 to t3).

Thereafter, the air conditioner switch 89 is turned off.
When F (elapsed time t4), the above air conditioner correction value ISC
AC is set to DSAC1D or D
The air conditioner correction value ISCAC is reduced by the amount of SAC1N until it reaches the set value ISCACD.

When the air conditioner switch 89 is turned off from ON to OFF, if the air conditioner correction value ISCAC is suddenly set to 0, the air conditioner clutch relay 65 is not turned on for a predetermined time after ON → OFF, especially since the variable capacity air conditioner compressor 64 is used. Since the load is on (connected) and the load on the engine driven by the air conditioner compressor remains due to the air conditioner capacity control, the engine speed drops as shown by the broken line in FIG.

When the air conditioner correction value ISCAC reaches the set value ISCACD (elapsed time t5), the air conditioner correction value ISCAC is set to the set value DS for each operation cycle.
The air conditioner correction value ISCAC is reduced by 0 by AC2D or DSAC2N until it becomes zero.

The above set value DSAC2D or DSAC
Since 2N is smaller than the set value DSAC1D or DSAC1N, the convergence of the engine speed NE is improved. On the other hand, when the air conditioner correction value ISCAC is reduced with the large reduction value, the engine speed N near ISCAC = 0 as shown by the dashed line in FIG.
E has poor convergence.

(Air Conditioner Correction Learning Routine) FIG. 9 is a routine for executing an interrupt when the air conditioner switch 89 turns from OFF to ON. First, in step S101, the value of the closed / open loop control discrimination flag FLAGCL is referred to, and FLAGCL = 1.
In case of (closed loop control), proceed to S702, FLA
If GCL = 0 (during open loop control), the flow proceeds to S707.

In S702, the closed loop correction ISC _I , which is the current feedback control value set in the closed loop correction I minute update routine described later, is read, and the current I minute value MISC is stored in a predetermined address of the RAM 50.
It is stored as I (MISCI ← ISC _I ), the timer TIMERLRN is started in S703, it is determined whether or not the air conditioner switch 89 is ON in S704.
In the case of FF, proceed to S707. In step S705, the value of the closed / open loop control discrimination flag FLAGCL is referred to
If LAGCL = 1 (during closed loop control), proceed to S706; if FLAGCL = 0 (during open loop control)
Proceed to S707.

At S706, the timer TIMERLRN is compared with the preset time TACLRN, and the TIMER is set.
If RLRN ≧ TACLRN, it is determined that the air conditioner switch 89 has been turned on for a predetermined time during the closed loop control, and the process proceeds to S708, where TIMERLRN <TA
In the case of CLRN, the process returns to S704.

On the other hand, from S701, S704 or S705
When proceeding to S707, the timer TIMERLRN is reset (TIM
After ELRRN ← 0), exit the routine.

When the process proceeds to S708, the timer TIMER
After resetting LRN (TIMERLRN ← 0), the current ISC _I for the closed loop correction _I is read in S709,
It is stored in a predetermined address of the RAM 50 as the I-minute value LISCI after the elapse of the time TACLRN.

Then, the flow advances to S710, where the backup RAM is used.
The air conditioner correction learning value MACDTY stored at the predetermined address of 50a is updated with the value obtained from the following equation, and the process exits.

MACDTY ← MACDTY + [(LISCI−MISCI) × KACON] KACON: I-Migration Rate FIG. 10 shows a routine for executing an interrupt when the air conditioner switch 89 is turned ON → OFF. First, in S801, the closed / open loop control discrimination flag FLAGCL is set. With reference to the value of
If LAGCL = 1 (during closed loop control), proceed to S802. If FLAGCL = 0 (during open loop control), exit the routine.

In S802, the I component MISCI (air conditioner switch 8) stored at a predetermined address in the RAM 50
9 is read from OFF to ON), the current closed loop correction I minute ISC _I is read out in S803, and stored at a predetermined address of the RAM 50 as the I minute value LISCI (L
ISCI ← ISC _I ).

Then, the flow advances to S804, where the backup RAM is used.
The air conditioner correction learning value MACDTY stored at the predetermined address of 50a is updated with the value obtained from the following equation, and the process exits.

MACDTY ← MACDTY + [(LIS
CI−MISCI) × KACON] When the air conditioner correction value ISCAC in the P and N ranges is set, the air conditioner correction learning value MACDTY is used to compensate for the aging of the ISC valve 13 and the like.
At the time of N, a predetermined idle-up can always be performed. Since the engine load is relatively large in the traveling range as compared with the N and P ranges, the influence of the deterioration of the ISC valve 13 is small, and therefore, it is not necessary to use the learning correction value.

Further, the air conditioner switch 89 is turned from OFF to O
By executing not only the interrupt at the time of N but also the interrupt at the time of ON → OFF, the air conditioner correction learning value MACDTY set in the interrupt routine executed when the air conditioner switch 89 is turned OFF → ON and the previous OFF → ON. The deviation from the air conditioning correction learning value MACDTY set at the time can be compensated.

(AT Vehicle Running Range Correction Value Setting Subroutine) FIGS. 11 and 12 show the AT executed in the correction value setting routine interrupted every 51.2 msec (see S202).
This is a subroutine for setting a vehicle travel range correction value ISCATDS.

First, the running range determination flag FLA set in the air conditioner correction value setting subroutine described above in S901.
Referring to the value of GAT, if FLAGAT = 1 (running range), proceed to S902; if FLAGAT = 0 (P, N range)
Proceed to S903.

In S902, the running range shift determination count value COUNTAT1 (down counter) corresponding to the delay time ISCAT1 [sec] at the time of shifting from the P, N range to the running range set in S913 described later is referred to. If COUNTAT1 = 0, the process proceeds to S904. Further, C
If COUNTAT110, the process proceeds to S905, in which the count value COUNTAT1 of the travel range shift determination is counted down (C
OUNTAT1 ← COUNTAT1 -1) Go to S908.

In S902, the travel range state (neutral switch 59 and parking switch 60 are both turned off).
FF) continued for more than the delay time ISCAT1 (COUN
(TAT1 = 0) and proceeds to S904, the AT vehicle travel range correction value I stored at a predetermined address in the RAM 50 is determined.
Compare SCATDS with the set increase value DRGDTY,
If ATDS ≧ DRGDTY, the routine proceeds to S906, where the AT vehicle travel range correction value ISCATDS is set to the set increase value DRGDTY.
(ISCATDS ← DRGDTY), and the process proceeds to S908. If ISCATDS <DRGDTY, the routine proceeds to S907, where the AT vehicle travel range correction value ISCATDS is set to the set value DL.
The AT vehicle travel range correction value ISCATDS is set to a value obtained by adding TAT1 (however, DLTAT1 <DRGDTY) (ISCATDS ← ISCATDS + DLTAT1), and S908
Proceed to.

Then, from S905, S906, or S907
When proceeding to S908, the set value COU corresponding to the delay time ISCAT2 [sec] when shifting from the traveling range to the N and P ranges
NTISCAT2, N, P range shift judgment count value COUN
Set TAT2 (COUNTAT2 ← COUNTISCA
T2), exit the routine.

On the other hand, in S901, the N and P ranges (FLAGAT =
0) and the process proceeds to S903, referring to the N, P range shift determination count value COUNTAT2, and
In the case of へ 0, proceed to S909 and the above count value COUNTAT2
Count down (COUNTAT2 ← COUNTAT
2-1), proceed to S913.

When it is determined in step S903 that COUNTAT2 = 0, the flow proceeds to step S910, where the AT vehicle travel range correction value I
Judge whether SCATDS is 0 or less, and if ISCATDS> 0, S9
Proceed to 11 to set the AT vehicle travel range correction value ISCATDS with a value obtained by subtracting the set value DLTAT2 from the AT vehicle travel range correction value ISCATDS (ISCATDS ← ISCATDS-D).
LTAT2), and proceed to S913. If ISCATDS ≦ 0, the routine proceeds to S912, where the AT vehicle traveling range correction value ISCATDS is set to 0 [%] (ISCATDS ← 0), and the routine proceeds to S913.

Then, from S909, S911, or S912
Proceeding to S913, the running range shift determination count value CO with the set value COUNTISCAT1 corresponding to the delay time ISCAT1 [sec] when shifting from the N, P range to the running range.
After setting UNTAT1 (COUNTAT1 ← COUN
TISCAT1), exit the routine.

A typical example of the setting of the AT vehicle running range correction value will be described with reference to the time chart of FIG.

When shifting from the N and P ranges (FLAGAT = 0) to the running range (FLAGAT = 1) (elapsed time t
1) The clocking of a predetermined delay time ISCAT1 [sec] is started, and after the delay time ISCAT1 [sec], a small set value DLTAT1 [%] is added for each operation cycle (ISCATDS ← ISCATDS + DLTAT1), and the AT vehicle is started. The travel range correction value ISCATDS [%] is the set value DRGDT
When Y [%] is reached (elapsed time t2), the AT vehicle travel range correction value ISCATDS [%] is changed to the set value DRGDT.
It is fixed at Y [%] (elapsed time t2 to t3).

When shifting from the N and P ranges to the driving range, the load is applied to the engine with a small delay time, so that the AT vehicle driving range correction value ISCATDS is immediately changed from 0 to →.
When the set value DRGDTY [%] is set, the engine speed NE temporarily increases as shown by the broken line in FIG.

If the AT vehicle travel range correction is not performed, the engine load is suddenly applied when shifting from the N, P range to the travel range, and the engine speed decreases as shown by the two-dot chain line in FIG. Thus, it takes time for the engine speed to converge due to the closed loop correction ISC _I.

On the other hand, when shifting from the running range (FLAGAT = 1) to the N, P range (FLAGAT = 0) (elapsed time t3), the counting of a predetermined delay time ISCAT2 [sec] is started, and the delay time ISCAT2 [sec] is started. After the elapse, the AT vehicle travel range correction value ISCATDS is decremented by a small amount set value DLTAT2 [%] in every operation cycle until it becomes 0 (ISCATDS ← ISCATDS-DLTAT2, elapsed time t4).

When the vehicle shifts from the driving range to the N and P ranges, the engine load suddenly decreases with a small delay time. Therefore, if the AT vehicle driving range correction value ISCATDS [%] is immediately set to 0, the transmission to the engine on the transmission side is stopped. Since the load is not completely removed, the engine speed temporarily decreases as shown by the broken line in FIG.
If the AT vehicle traveling range correction is not performed, when the traveling range is shifted from the traveling range to the N and P ranges, the engine load sharply decreases, so that the engine speed increases as shown by the two-dot chain line in FIG. The resulting feeling deteriorates.

(Acceleration / Deceleration Correction Value Setting Subroutine) FIGS. 13 and 14 are acceleration / deceleration correction value DSHPT setting subroutines (see S203) executed in a correction value setting subroutine interrupted every 51.2 msec.

First, in S1001, it is determined whether or not the idle switch 12b is OFF.
If the throttle valve is in the open state (11e is open), the flow proceeds to S1002, and if it is ON (the throttle valves 11d and 11e are fully closed), the flow proceeds to S1003.

When the flow advances to S1002, the travel range determination flag FL
Refer to the value of AGAT, FLAGAT = 0 (N, P range)
In the case of, the process proceeds to S1004, and in the case of FLAGAT = 1 (running range), the process proceeds to S1005.

When the flow advances to S1004, the throttle opening sensor 12
ROM 49 based on the throttle opening THV detected in step a.
After setting the acceleration / deceleration correction value DSHPT [%] by referring to the N / P range acceleration / deceleration correction value table TDASHN stored at a series of addresses with interpolation calculation, the process proceeds to S1006.

Further, when the process proceeds from S1002 to S1005, the acceleration / deceleration correction value table TD for the traveling range stored in a series of addresses in the ROM 49 based on the throttle opening THV.
Acceleration / deceleration correction value DSH with reference to ASHD with interpolation calculation
After setting PT [%], the process proceeds to S1006.

When the select lever is shifted to the N range or the P range, no load is applied to the engine, and when the throttle valves 11d and 11e are opened, racing, air blowing, etc., are performed. The change in the engine speed NE according to the degree change is larger than in the travel range.

[0176] Thus, N, acceleration correction value DSHPT to the throttle opening THV stored in each region of the P-range for deceleration correction value <br/> table TDASHN is running range for acceleration and deceleration to adopt during driving range Acceleration / deceleration correction value DSHP stored in correction value table TDASHD
T is set to a large value, so that controllability according to the engine load can be obtained.

[0177] Then, the process proceeds when the acceleration correction value current acceleration correction value stored in a predetermined address of the RAM50 in DSHPT from S1004 or S1005 to S1006 (D
(SHPT) Set NEW ((DSHPT) NEW ← DSH
PT).

Thereafter, when the flow advances to S1007, the acceleration / deceleration correction value (DSHPT) NEW set this time is compared with the acceleration / deceleration correction value (DSHPT) OLD set in the previous routine, and (D
If (SHPT) NEW <(DSHPT) OLD (throttle opening decreases), proceed to S1008, where (DSHPT) NEW ≧ (DSH)
If (PT) OLD (throttle opening increases or does not change), jump to S1030.

When the flow advances to S1008, the traveling range determination flag FL
Refer to the value of AGAT, FLAGAT = 0 (N, P range)
If so, proceed to S1009; if FLAGAT = 1 (running range), proceed to S1010.

At S1009, the first set value DDASHN is set.
To set the weight loss value DDASH [%] (DDASH ← D
DASHN), and proceed to S1011. Further, when the process proceeds to S1010, the second set value DDASHD (where DDASHN> DDA
SHD) and set the weight loss value DASHH [%] (DDA
(SH ← DDASHD), and proceeds to S1011.

It should be noted that the decrease in the engine speed when the throttle opening is reduced is smaller than in the running range in the no-load state.
Because the P range is quicker, (DSHPT) NEW <
The deceleration value DDASH of the acceleration / deceleration correction value DSHPT at the time of (DSHPT) OLD is set larger than the travel range at the time of the N and P ranges.

Then, when the flow advances to S1011, the previous acceleration / deceleration correction is performed.
The acceleration / deceleration correction value DSHPT is set with a value obtained by subtracting the above-mentioned weight reduction value DASH from the value (DSHPT) OLD (DSHPT).
T ← (DSHPT) OLD-DDASH).

On the other hand, at S1001, the idle switch 12
When it is determined that b is ON and the throttle is in the fully closed state and the process proceeds to S1003, the value of the travel range determination flag FLAGAT is referred to, and
If FLAGAT = 0 (N, P range), proceed to S1012,
If FLAGAT = 1 (running range), proceed to S1013.

At S1012, the set value NDASHN [%]
To set the offset value NDASH (NDASH ← ND
ASHN), and when the processing proceeds to S1013, the set value NDASHD
(However, NDASHN> NDASHD) [%] sets the offset value NDASH (NDASH ← NDASH).
D), and then proceed to S1014, respectively.

Then, when the flow advances to S1014, the engine speed N
The offset value ND is added to E and the target idle speed NSET.
Compare with the value obtained by adding ASH, and NE ≧ NSET + NDA
If SH, proceed to S1015, and if NE <NSET + NDASH, proceed to S1016.

When the flow advances to S1015, the travel range determination flag FL
Refer to the value of AGAT, FLAGAT = 0 (N, P range)
In step S1017, the process proceeds to step S1017, where the dashpot holding value RDASH is set with a preset set value RDASHN [%] (RD
ASH ← RDASHN), and if FLAGAT = 1 (running range), proceed to S1018 and hold the dashpot holding value RD
ASH is set by a preset set value RDASHD [%] (RDASH ← RDASHD), and thereafter, the process proceeds to S1019.

When the flow advances to S1019, the current acceleration / deceleration correction value DSH stored at a predetermined address in the RAM 50 is obtained.
PT, the acceleration / deceleration correction value DSHPT is compared with the dashpot holding value RDASH, and DSHPT ≦
In the case of RDASH, proceed to S1020, set the acceleration / deceleration correction value DSHPT with the dashpot holding value RDASH (DSHPT ← RDASH), and proceed to S1030.

If it is determined in step S1019 that DSSHP> RDASH and the flow advances to step S1021, the traveling range determination flag FLA is set.
Referring to the value of GAT, if FLAGAT = 0 (N, P range), proceed to S1022, and if FLAGAT = 1 (running range), proceed to S1023.

When the flow advances to S1022, the set value DDSH1N [%]
To set the first weight loss value DDSH1 (DDSH1 ← DD
SH1N), and if it proceeds to S1023, the set value DDSH1D
(However, DDSH1D <DDSH1N) [%] sets the first weight loss value DDSH1 (DDSH1 ← DDSH1).
D), and then proceed to S1024 respectively.

Then, when the flow advances to S1024, the acceleration / deceleration correction value DS
After setting the acceleration / deceleration correction value DSHPT with a value obtained by subtracting the first weight loss value DDSH1 from the HPT (DSHPT
← DSHPT-DDSH1), proceed to S1030.

[0191] On the other hand, the process proceeds to S1016 it is determined that NE <NSET + NDASH in S1014, it is determined whether deceleration correction value DSHPT is 0 or less, the process proceeds to S1025 if the DSHPT ≦ 0, fixing the acceleration correction value DSHPT 0 (DSHPT ←
After 0), proceed to S1030. If DSHPT> 0, the process proceeds to S1026.

At S1026, the running range determination flag F is set.
With reference to the value of LAGAT, if FLAGAT = 0 (N, P range), proceed to S1027, and if FLAGAT = 1 (running range), proceed to 1028.

At S1027, a second weight loss value DDSH2 is set with the set value DDSH2N (where DDSH1N> DDSH2N) [%] (DDSH2 ← DDSH2N), and
When the process proceeds to S1028, the set value DDSH2D (however, DD
SH1D> DDSH2D) [%] and the second weight loss value DDS
Set H2 (DDSH2 ← DDSH2D), and set
Proceed to S1029.

[0194] After setting the deceleration correction value DSHPT in the S1029 in deceleration correction value DSHPT value obtained by subtracting the second weight loss values DDSH2 (DSHPT ← DSHPT
-DDSH2), proceed to S1030.

The first and second weight loss values DDSH1, DD
Each set value DDSH1N, DDSH2 for setting SH2
N, DDSH1D, DDSH2D, DDSH1N> DD
By setting SH2N, DDSH1D> DDSH2D, when the engine speed NE drops to the idle target speed NSET when the throttle is fully closed , if the engine speed NE approaches the idle target speed NSET, the acceleration / deceleration correction value is set. by the this is a small value to decrease value for DSHPT, convergence to the target idle speed NSET the engine speed NE is improved, it is possible to prevent hunting of the control.

Then, S1007, S1011, S1020, S1024, S1025
Alternatively, when proceeding from S1029 to S1030, S1004, S1005, S101
The previous acceleration / deceleration correction value (DSHPT) OLD stored at a predetermined address in the RAM 50 is updated with the acceleration / deceleration correction value DSHPT set in 1, S1020, S1024, S1025, or S1029, and ((DSHPT) OLD ← DSHPT ), Exit the routine.

A typical example of the setting of the acceleration / deceleration correction value will be described with reference to the time chart of FIG.

The idle switch 12b changes from ON (throttle valves 11d and 11e are fully closed) to OFF (throttle valves 11d and 11e are open) (elapsed time t1).
In the acceleration operation in which the throttle opening THV gradually increases, the engine speed NE increases in accordance with the throttle opening THV. At this time, the acceleration / deceleration correction value DSHPT set based on the throttle opening THV increases in each calculation cycle, and the duty ratio ICON of the ISC valve 13 set by taking in the acceleration / deceleration correction value DSHPT (ISCTR) increases. The opening of the ISC valve 13 is increased (elapsed times t1 to t2 and t3 to t4).

In a steady operation in which the throttle opening THV is substantially constant, the acceleration / deceleration correction value DSHPT is constant (elapsed times t2 to t3 and t4 to t5).

When the throttle valves 11d and 11e are suddenly closed, the pressure in the intake pipe rapidly decreases, and the fuel adhering to the intake port 4 and the inner wall surface of the intake manifold 5 is sucked into the combustion chamber at a stretch. The air-fuel ratio becomes over-rich due to a decrease in the intake air amount due to the rapid closing of the throttle valves 11d and 11e. However, when the throttle valves 11d and 11e are closed (elapsed time t5), the throttle valve opening THV is increased. It is set deceleration correction value DSHPT according to this acceleration correction value D
By setting the duty ratio ISCON large by the amount of SHPT , ISC is proportional to the throttle opening THV.
The opening of the valve 13 is secured, and the throttle valve 11
After the valve closing transition of d and 11e, the idle switch 12b is
Until N (throttle fully closed) (elapsed time t5 to t
6) The acceleration / deceleration correction value DSHPT is
Calculation cycle ( 51.2msec) regardless of valve closing speed of d and 11e
Each time, the set value DDASH is decreased by the set value DDASH.

Therefore, during this time, the ISC valve 13 secures the air amount, compensates for the decrease in the intake pipe pressure, and prevents the air-fuel ratio from being over-rich. As a result, misfire and abnormal combustion due to the air-fuel ratio over-rich immediately after the throttle valve suddenly closes are prevented, and the exhaust emission is improved.

Since the acceleration / deceleration correction value DSHPT at the time of shifting from the throttle valve open state to the throttle fully closed state is set to a value corresponding to the throttle opening THV,
The dashpot period after shifting to the fully closed throttle is always obtained properly.

When the idle switch 12b is turned on, the acceleration / deceleration correction value DSHPT is increased to the dashpot holding value RDASH by the first set value DDSH1 every calculation cycle.
(However, DDASH>DDSH1> DDSH2) is decreased in increments (elapsed time t6 to t7). As a result, when the throttle is fully closed, the rate of decrease of the acceleration / deceleration correction value DSHPT becomes relatively large, and the time required to return to the target rotational speed is reduced.

Thereafter, when the acceleration / deceleration correction value DSHPT reaches the dashpot holding value RDASH, this value is
The engine speed NE is maintained until it decreases to a value obtained by adding the offset value NDASH to the idle target speed NSET (elapsed time t7 to t8), and the engine speed NE is obtained by adding the offset value NDASH to the idle target speed NSET. When the engine speed NE drops below the first set value DD, the engine speed NE reaches the target idle speed NSET.
The acceleration / deceleration correction value DSHPT is subtracted by a second set value DDSH2 smaller than SH1 for each calculation cycle (after the elapsed time t8).

As a result, the idle switch 12b is turned on.
Thereafter, until the engine rotational speed NE reaches the idle target rotational speed NSET, the decreasing rate of the duty ratio ISCON set using the acceleration / deceleration correction value DSHPT sequentially decreases, and the opening degree decreasing rate of the ISC valve 13 also increases. It becomes smaller sequentially.
Thus, the rate of decrease in engine rotational speed NE when approaching the target idle speed NSET is reduced, engine stall is proof <br/> stop Rutotomoni, convergence to the target idle speed NSET the engine rotational speed NE Is improved.

(Dashpot Correction Value Setting Interruption Routine) FIG. 15 is a dashpot correction value setting routine that executes an interruption every set time, for example, every 100 msec.

First, in S1101, it is determined whether or not the idle switch 12b is ON.
If e is fully closed), the flow proceeds to S1102, and if OFF (throttle valves 11d and 11e are open), the flow proceeds to S1104.

In step S1102, the engine speed NE is compared with a preset dashpot determination engine speed DHEKN.
If NE <DHEKN, proceed to S1103, and NE ≧ DHEK
If N, proceed to S1104. The dashpot determination rotational speed DHEKN is a value near the idle rotational speed (for example, 1900 rpm) in consideration of idle-up such as air conditioner correction.

When the process proceeds from S1101 or S1102 to S1104, the dashpot correction value DHENB is set to 0 (DHEN).
After B ← 0), the flow proceeds to S1113.

When the flow advances from S1102 to S1103, the engine speed (NE) OLD set at the time of execution of the previous routine (100 msec before) and stored at a predetermined address in the RAM 50 is read out.
In S1105, the engine speed reduction amount NDOWN in the set time (100 msec) is calculated from the difference between the previous engine speed (NE) OLD and the current engine speed NE (NDOWN ←
(NE) OLD). Here, engine rotation per set time
The number reduction amount NDOWN represents the engine speed reduction speed.

Then, in S1106, the engine speed reduction amount NDOWN is compared with the set value DNES1, and NDOWN <DN
In the case of ES1, proceed to S1107, and set the engine speed reduction amount discrimination flag FLAGDH indicating that the engine speed reduction amount is small (slow deceleration) (FLAGDH ← 1).
Then, the process proceeds to S1114.

When it is determined in step S1106 that NDOWN≥DNES1, the routine proceeds to step S1108, where the engine speed reduction amount NDO is determined.
WN and set value DNES2 (However, DNES1 <DNES
2), and if NDOWN <DNES2, the process proceeds to S1109 and sets the dashpot correction value DHENB to the set value DHNEB.
Set with 1 [%] (DHENB ← DHNEB1), S111
Proceed to 3. If NDOWN ≧ DNES2, the process proceeds to S1110.

In S1110, the engine speed reduction amount N
DOWN and set value DNES3 (however, DNES2 <DNES
3), and if NDOWN <DNES3, the process proceeds to S111 and sets the dashpot correction value DHENB to the set value DHNEB2.
(However, DHNEB1 <DHNEB2) [%] is set (DHENB ← DHNEB2), and the process proceeds to S1113. Also,
If NDOWN ≧ DNES3, the process proceeds to S1112, where the dashpot correction value DHENB is set to the set value DHNEB3 (however, DHN
EB2 <DHNEB3) [%] and set (DHENB ←
DHNEB3), and proceed to S1113.

The above S1104, S1109, S1111, S1112 to S1113
When the routine proceeds to (1), the engine rotational speed decrease amount determination flag FLAGDH is cleared (FLAGDH ← 0, the decrease amount is large), and the routine proceeds to S1114.

Then, S1107 or S1113 to S1114
When the process proceeds to step S3, the current engine speed NE is stored at a predetermined address in the RAM 50 at the previous engine speed (N
E) Update OLD ((NE) OLD ← NE) and exit the routine.

FIG. 16 shows a dashpot correction value updating subroutine executed (see S204) in a correction value setting routine interrupted every 51.2 msec.

First, in S1201, the value of the engine rotational speed decrease amount discrimination flag FLAGDH is referred to. If FLAGDH = 1 (decrease amount), the process proceeds to S1202, and if FLAGDH = 0 (decrease amount), the routine exits.

When the flow advances to S1202, the dashpot correction value DH
It is determined whether ENB [%] is equal to or less than 0, and if DHENB ≦ 0, the process proceeds to S1203 and the dashpot correction value DHENB is set to 0.
After setting to [%] (DHENB ← 0), the routine exits.

If it is determined in step S1202 that DHENB> 0, and the flow advances to step S1204, the dashpot correction value DHEN
The dashpot correction value DHENB is set by a value obtained by subtracting the set value DDFEB (small value) from B (DHENB).
← DHENB-DDFEB) and exit the routine.

FIG. 32 is a time chart showing a typical example of setting a dashpot correction value.

At the time of sudden deceleration due to sudden closing of the throttle valves 11d and 11e, the idle switch 12b shifts from the OFF state to the ON state (the throttle valves 11d and 11e are fully closed) and the engine speed NE sharply decreases. ,
Dashpot determination rotation speed DHEKN (for example, 1900 rp)
m) or less and the engine speed reduction amount NDOWN is relatively large (DNES3 ≦ NDOWN) (elapsed time t1 to t).
In 2), the dashpot correction value DHENB is set with the large set value DHNEB3 [%].

If the dashpot correction is not performed when the engine speed NE suddenly drops, the engine speed drops and stalls as shown by the broken line in the figure. Therefore, when the engine speed NE suddenly drops below a set value DHEKN (for example, 1900 rpm) near the idle speed when the throttle valves 11d and 11e shift from the open state to the fully closed state, the engine speed By increasing the dashpot correction value DHENB as the decrease amount NDOWN (= (NE) OLD-NE) of the ISC valve 13 is increased, the duty ratio ISCON for the ISC valve 13 is increased, and the opening of the ISC valve 13 is increased to increase air. Increase the amount to prevent the engine speed NE from dropping.

After that, the engine speed reduction amount NDOWN is
Section of DNES2 ≦ NDOWN <DNES3 (elapsed time t2
In t3), the dashpot correction value DHENB is set at the intermediate set value DHNEB2 [%].

Next, the engine speed reduction amount NDOWN is calculated as follows:
Section of DNES1 ≦ NDOWN <DNES2 (elapsed time t3
To t4), a relatively small set value DHNEB1
The dashpot correction value DHENB is set in [%].

If the dashpot correction value DHENB is kept at the set value DHNEB3 even when the engine speed reduction amount NDOWN is relatively small, a rotation fluctuation occurs as shown by a chain line in FIG. Convergence deteriorates.

Then, the engine speed reduction amount NDOWN
However, in the section of NDOWN <DNES1 (after the elapsed time t4), the dashpot correction value DHENB is decremented by a small set value DDFEB every calculation cycle (51.2 msec) until it becomes zero.

That is, when the dashpot correction value DHENB is set to 0 at the elapsed time t4, the ISC valve 13
, The engine speed NE drops as shown by the broken line in the figure, and the convergence to the idle speed deteriorates. Accordingly, the dashpot correction value DHENB is reduced in accordance with the decrease in the decrease amount NDOWN of the engine speed NE to improve the convergence to the idle speed.

(Radio fan correction setting subroutine) FIG.
7 is a radi fan correction ISCRAS executed in a correction value routine interrupted every 51.2 msec (see S205).
This is a setting subroutine.

First, in S1301, the main computer 41
It is determined whether the radiator fan relay 63 for controlling the operation of the radiator fan 62 is ON based on the data in the
If it is ON, proceed to S1302; if it is OFF, proceed to S1303.

When the flow advances to S1302, the radial fan correction ISCRAS stored at a predetermined address in the RAM 50 is set to the set value R.
Set with AS [%] (ISCRAS ← RAS) and exit the routine. In addition, the process proceeds to S1303, where
Set SCRAS to 0 [%] (ISCRAS ← 0) and exit the routine.

FIG. 33 is a time chart showing the setting of the above-mentioned radial fan correction ISCRAS.

When the radiator fan 62 is operating, the radiator fan motor consumes a large amount of current,
Since the amount of power generated by the alternator (generator) also increases, the load on the engine 1 increases accordingly and the engine speed NE tends to decrease. However, when the radiator fan 62 is ON, the duty with respect to the ISC valve 13 is reduced. The ratio ICON is increased by the radiator fan correction ISCRAS, and the opening of the ISC valve 13 is increased to prevent the engine speed NE from lowering.

(Power Steering Correction Value Setting Subroutine) FIG.
8 and FIG. 19 show a subroutine for setting a power steering correction value ISCPS which is executed (see S206) in a correction value setting routine executed by interruption every 51.2 msec. The power steering correction value ISCPS set in this subroutine is for compensating that the turning angle is large and the load on the engine 1 that drives the power steering oil pump increases, and the engine speed NE decreases.

First, at step S1401, a power steering turning switch (hereinafter abbreviated as "power steering turning switch") 5
It is determined whether or not 8 is ON. If it is ON (large turning angle), the process proceeds to S1402, and if it is OFF (low turning angle), the process proceeds to S1409.

In S1402, the vehicle speed VSP detected by the vehicle speed sensor 56 is compared with the set value VSPPS [Km / h], and
If P ≦ VSPPS, proceed to S1403; if VSP> VSPPS, proceed to S1409.

In S1403, the cooling water temperature T W detected by the cooling water temperature sensor 21 is compared with a set value T WPS [° C].
If TW ≧ TWPS, proceed to S1404, if TW <TWPS
Proceed to S1409.

In S1402, when the vehicle speed VSP is equal to or higher than the set value VSPPS, the engine load for driving the power steering oil pump is relatively small because the engine load due to traveling is large. Therefore, the power steering correction value IS
Eliminates the need for CPS compensation.

In S1403, the warm-up is not completed (TW <
TWPS), the basic characteristic value ISCTW is set large, so that the engine load for driving the power steering oil pump becomes relatively small, and the power steering correction value ISCPS
No compensation is required.

In S1404, the value of the idle speed discrimination flag FLAGPS set to 1 when the engine was idling at the time of execution of the previous routine is referred to as FLAGPS = 1.
In the case of (last idle state), proceed to S1405, and FLAGPS
If = 0 (previous idle release state), the process proceeds to S1406.

At S1405, the set value ISPSN [rpm
] To set the idle discrimination rotational speed ISPSN (ISP
SN ← ISPSNH), and proceeds to S1407. Further, when the process proceeds to S1406, the set value ISPSNNL (however, ISPSNNL <IS
(PSNH) [rpm] to set the idle discrimination rotational speed ISPSN (ISPSN ← ISPSNL), and proceed to S1407.
As shown in FIG. 34, by setting the hysteresis between the idle state (FLAGPS = 1) and the idle release state (FLAGPS = 0) when setting the idle determination rotation speed ISPSN, the control hunting of the idle state determination in S1407 is performed. I try to prevent it.

In S1407, the engine speed NE is compared with the idling speed ISPSN, and NE> ISPS.
In the case of N, it is determined that the idle is released, and the process proceeds to S1408, where the idle speed determination flag FLAGPS is cleared (FLAGPS
After ← 0), go to S1409. If NE ≦ ISPSN, it is determined that the engine is in the idle state, and the flow advances to S1410.

In S1410, the air conditioner switch 89 is turned off.
If it is OFF, proceed to S1411; if it is ON, S1
Proceed to 412.

At S1411, the main computer 41
Duty ratio IS for ISC valve 13 calculated by
Based on CON, power steering correction value IS when air conditioner is off
The CPS is set by referring to the table or by calculation, and S1413
Proceed to. Further, when the processing proceeds to S1412, the main computer 41
Duty ratio IS for ISC valve 13 calculated by
Power steering correction value ISCPS when air conditioner is ON based on CON
Is set by referring to the table or by calculation, and the process proceeds to S1413.

As shown in FIG. 35 (b), the power steering correction value ISCPS when the air conditioner is turned off indicated by a solid line is set to be larger than the power steering correction value ISCPS when the air conditioner is turned on indicated by a dashed line. That is, when the air conditioner is ON, the duty ratio ISCON is set to be large by the air conditioner correction value ISCAC, so that the engine load due to power steering is relatively reduced, and therefore, the power steering correction value ISCPS is set smaller than when the air conditioner is OFF.

The power steering correction value ISCPS set in S1411 or S1412 is such that when the duty ratio ISCON is large (small), the load on the engine 1 is large (small) and the opening of the ISC valve 13 is large (small). Although the air amount is increased (decreased) to prevent the engine speed NE from decreasing (increased), the load by the power steering pump is relatively small (large) with respect to the total load applied to the engine at this time. Therefore, it is set small (large).

Then, from S1411 or S1412 to S1
In 413, the idle speed discrimination flag FLAGPS is set (FLAGPS ← 1), and the routine exits.

Also, S1401, S1402, S1403, or S140
When the process proceeds from S8 to S1409, it is determined whether the power steering correction value ISCPS is equal to or less than 0. If ISCPS ≦ 0, the process proceeds to S1414, and the power steering correction value ISCPS is set to 0 [%] (ISCPS ←
0), exit the routine. S141 if ISCPS> 0
Proceed to 5 to change the power steering correction value ISCPS to the set value DISC.
After the power steering correction value ISCPS is updated by subtracting PS (ISCPS ← ISCP-DISCPS), the routine exits.

FIG. 35 shows a typical time chart for setting the power steering correction value.

At the time of idling after the completion of warm-up, when the turning angle becomes large and the power steering turning switch 58 is turned on, the power steering correction value ISCPS corresponding to the duty ratio ISCON (depending on whether the air conditioner switch 89 is off or not, is different. Is set (elapsed time t1).

As a result, when the power steering oil pump driving load increases due to the large turning angle, the power steering correction value IS
Duty ratio IS for ISC valve 13 by CPS
By increasing CON and increasing the opening of the ISC valve 13 to increase the amount of air, a drop in the engine speed is prevented.

Also, immediately after the power steering switch 58 is switched from ON to OFF (elapsed time t2), the power steering correction value ISCPS is immediately set to 0 [%]. Ratio ISC
Since ON is rapidly decreased by the power steering correction value ISCPS and decreased, but the power steering oil pump driving load is present, the engine speed N as shown by the two-dot chain line in FIG.
E fluctuates greatly, but the power steering correction value IS
Until CPS becomes 0, the power steering correction value ISCPS is subtracted by the set value DISCSP every calculation cycle (51.2 msec), thereby gradually decreasing the opening of the ISC valve 13 to compensate for the air amount. The fluctuation of the engine speed NE is prevented as shown by the solid line in FIG.

(Air Conditioner Clutch Correction Value Setting Subroutine) FIG. 20 is a subroutine for setting the air conditioner clutch correction value ISCCLH executed in the correction value setting routine interrupted every 51.2 msec (see S207). First, in S1501, it is determined whether the air conditioner switch 89 is ON.
If it is ON, proceed to S1502; if it is OFF, proceed to S1503.

In S1502, the air conditioner switch 89 is turned on.
N → Air conditioner ON → OFF elapsed time determination count value C for determining whether a predetermined time TCLH [SEC] has elapsed since OFF
COUNTCLH is set with a set value TACCLH corresponding to the predetermined time TCLH (COUNTCLH ← TACCL).
H), proceed to S1505.

[0254] When the flow advances to S1503, the air conditioner is turned on → OF.
With reference to the value of the elapsed time determination count value COUNTCLH after F, if COUNTCLH ≠ 0, the process proceeds to S1504, and after counting down (COUNTCLH ← COUNTCLH−1), the process proceeds to S1505.

When the process proceeds from S1502 or S1504 to S1505, the air conditioner clutch correction value ISCCLH is set to the set value DISCL.
After setting in H [%] (ISCCLH ← DISCLH),
Exit the routine.

On the other hand, since COUNTCLH3 = 0 in S1503, it is determined that the predetermined time TCLH [SSEC] has elapsed after the air conditioner switch 89 has been turned ON → OFF, and the flow proceeds to S1506. After setting (ISCCLH ← 0), exit the routine.

FIG. 36 shows the air conditioner clutch correction value IS.
Setting of CCLH and ON / OF of air conditioner switch 89
F, ON / OFF of the air conditioner clutch relay 65, displacement control of the variable displacement air conditioner compressor 64, and the relationship with the engine speed NE.

First, the variable capacity air conditioner compressor 64
Is described below. Air conditioner switch 8
When 9 is turned on, the main computer 41 turns on the air conditioner clutch relay 65 after the set delay time ACENT (for example, 0.3 sec) has elapsed, connects the magnet clutch 64a of the variable capacity air conditioner compressor 64, drives the compressor 64, and A compressor capacity (DUTY) signal is output from the air conditioner control unit 81 to the compressor 64 in accordance with the required capacity signal from the computer 41, and the capacity of the compressor 64 is reduced to the minimum capacity (MI
N) to the set capacity. When the air conditioner switch 89 is turned off, the compressor capacity (DUT
Y) The signal causes the capacity of the compressor 64 to gradually decrease to the minimum capacity (MIN). After the air conditioner switch 89 is turned off, a sufficient time that the capacity of the air conditioner compressor 64 can be considered to have reached the minimum capacity (MIN), Time A
After a lapse of CCLTM (for example, 8 seconds), the air conditioner clutch relay 65 is turned off.

Therefore, at the same time when the air conditioner switch 89 is turned on (elapsed time t1), the air conditioner clutch correction value IS
Set CCLH to the set value DISCLH and set ISC valve 1
3 is increased by the air conditioner clutch correction amount ISCCLH to increase the opening degree of the ISC valve 13 and increase the amount of air, thereby increasing the engine speed NE and turning on the air conditioner clutch relay 65.
To prevent a decrease in the engine speed due to an increase in the engine load driven by the compressor 64.

Thereafter, when the air conditioner switch 89 is turned off (elapsed time t2), the capacity of the variable capacity air conditioner compressor 64 is gradually reduced, and the above-described air conditioner correction value ISCAC is gradually reduced (FIGS. 7, 8 and 9). 29), the duty ratio ICON with respect to the ISC valve 13 decreases, and the ISC valve 1
3, the air amount decreases and the engine speed N
E is returned to the target rotation speed when the air conditioner is turned off.

From the time when the capacity of the variable capacity air conditioner compressor 64 has completely decreased (elapsed time t3), the time until the magnetic clutch 64a is disengaged (the air conditioner clutch relay
During the time T1 (until is turned off), the friction of the clutch remains. Therefore, at the moment when the magnet clutch 64a of the variable capacity air conditioner compressor 64 is disengaged, the friction by the clutch suddenly disappears, and as shown by the broken line in FIG. Will get worse.

The air conditioner clutch correction is for compensating the engine load due to the friction of the clutch. After the air conditioner switch 89 is turned on, the air conditioner switch 89 is turned off, and after the set time ACCLTM has elapsed, the air conditioner clutch relay 65 is turned off. Then, until the magnet clutch 64a of the variable displacement air conditioner compressor 64 is completely disengaged,
After FF, a predetermined time TACCLH (TACCLH> ACC
LTM), air conditioner clutch correction I
SCCLH is set to the set value DISCLH, and the duty ratio ISCON for the ISC valve 13 is increased during this time.
By setting the air conditioner clutch correction ISCCLH to 0 when the air conditioner clutch 64a is disengaged, the air conditioner clutch 6
At the moment when 4a is disconnected, the friction by the clutch disappears and the engine load is reduced, so that ICON is reduced to reduce the opening of the ISC valve 13 to reduce the amount of air, thereby preventing the rotation fluctuation at this time. As a result, as shown by the solid line in FIG. 9E, the rotational fluctuation due to the temporary increase in the rotational speed immediately after the air conditioner clutch 64a is disengaged is eliminated, and the feeling is improved.

(Post-Start Correction Setting Interrupt Routine) FIG.
Is a post-start correction initial value setting routine that executes an interrupt when the start / normal control discrimination flag FLAGST set in the ISC valve control main routine changes from 1 to 0.

Start / normal control discrimination flag FLAGST
From FLAGST = 1 (startup control) to FLAGST = 0
(Normal control), that is, the starter switch 61 is changed from ON to OFF, and the engine speed N
When an interrupt is started immediately after the start-time control when E is NE ≠ 0, first, in S1601, a post-start correction initial value table TISCSD based on the cooling water temperature TW (a larger value is stored as the cooling water temperature TW is lower). Is referenced with interpolation calculation to set the initial value of the post-start correction ISCSD. Next, in step S1602, the post-start correction update interrupt time is referred to by interpolation calculation with reference to the post-start correction update interrupt time table TTDISC (a longer time value is stored as the cooling water temperature TW is lower) based on the cooling water temperature TW. Set TDISC.

Then, in step S1603, an interruption for each post-start correction update interruption time TDISC is permitted, and the routine exits.

FIG. 22 is a post-start correction update setting routine that is executed every interruption time of the post-start correction update interrupt, and improves the connection of the duty ratio ISCON from the start control to the normal control to improve the startability. It is.

First, in S1701, it is determined whether the post-start correction ISCSD stored at a predetermined address in the RAM 50 is 0 or less. If ISCSD> 0, the flow advances to S1702 to go to S1702.
Update CSD with the value subtracted by the set value DISCSD (IS
CSD ← ISCSD−DISCSD), and exit the routine.

On the other hand, in S1701, it is determined that ISCSD ≦ 0,
In S1703, the post-start correction ISCSD stored at a predetermined address in the RAM 50 is fixed to 0 [%] (IS1703).
CSD ← 0), proceed to S1704, and start correction update interrupt time T after start
Disable interrupts for each DISC and exit the routine.

A representative example of the post-start correction setting will be described with reference to the time chart of FIG.

When the starter switch 61 is turned on, or
When the engine speed NE is 0 (start / normal control discrimination flag FLAGST = 1), the start-up switch 61 does not execute the post-start correction program (elapsed time t0 to t1).
Immediately after ON → OFF, and the engine speed NE is NE ≠ 0
At this time, the initial value of the post-start correction ISCSD is set (elapsed time t1).

Next, the set value DIS is set for each post-start correction update interrupt time TDISC until the post-start correction ISCSD becomes 0.
Decrease by CSD.

FIG. 38 shows the relationship between the change in the duty ratio ICON for controlling the ISC valve 13 and the post-start correction ISCSD.

At the time of starting control (FLAGST = 1), the duty ratio ISCON set in the main routine of the ISC valve control is set to a relatively large value. Since the control is precisely performed by the correction term, the connection of the duty ratio ISCON is deteriorated as shown by the one-dot chain line in the figure, and the startability is reduced.

The post-start correction ISCSD is for compensating for this, and the duty ratio ISCON set in the start-time control is mostly based on the start-time characteristic value ISCST set based on the cooling water temperature TW. As the water temperature TW is lower, the starting characteristic value ISCST is set to be larger (see FIG. 1).
The step of the duty ratio ISCON with respect to the SC valve 13 increases.

For this reason, the lower the cooling water temperature TW is, the more the FIG.
As shown by the solid line in FIG. 7, the initial value of the post-start correction ISCSD is set to be large, and the post-start correction ISCSD is set to be long to increase the time until the post-start correction ISCSD becomes 0 (elapsed time t1). T3) On the other hand, as the cooling water temperature TW becomes higher, as shown by the broken line in FIG.
Reduce the initial value of SD and correct the correction interrupt time after starting TDI
By setting the SC short and shortening the time until the corrected ISCSD becomes 0 after the start (elapsed time t1 to t2), the ISC valve at the time of transition from the start control to the normal control under any temperature condition. 13 duty ratio IS
The connection of CON is smoothed as shown by the solid line in FIG.
A sudden change in the air flow rate by the SC valve 13 is prevented, and the startability is improved.

(Closed Loop Correction I Minute Update Routine) FIGS. 23 to 25 are flowcharts showing a closed loop correction I minute update procedure executed by interruption every set time, for example, every 10 msec.

First, in S1801, the value of the start / normal control discrimination flag FLAGST set in the ISC valve control main routine is referred to. If FLAGST = 1 (at start or during engine stall), the flow advances to S1802, and FLAGST = 0.
In the case of (normal time), the process proceeds to S1803.

When the flow proceeds to S1802, the normal control shift time discrimination count value COUNTSTI (down counter) for judging whether or not the set time LRNISS [SEC] has elapsed since the shift to the normal operation (normal control) after the start is obtained. A set value COUNTLRNISS corresponding to the set time LRNISS is set (COUNTSTI ← COUNTLRNISS), and the process proceeds to S1858, where the closed loop correction I is set to 0 [%].
Proceed to S1859.

Further, when the flow advances to S1803, the normal control shift time discrimination count value COUNTSTI is referred to,
If UNTSTI ≠ 0, after shifting to normal control, it is determined that the set time LRNISS has not elapsed, and the flow advances to S1804 to count down the count value COUNTSTI (C
COUNTSTI ← COUNTSTI -1), and proceed to S1805.
On the other hand, if COUNTSTI = 0, it is determined that the set time has elapsed since the shift to the normal control, and the flow proceeds to S1805.

In S1805, the cooling water temperature TW and the set temperature L
RNITW [° C.], and if TW ≧ LRNITW, proceed to S1806; if TW <LRNITW, proceed to S1810. When the process proceeds to S1806, the value of the start / normal control discrimination flag (FLAGST) OLD read during the previous routine execution is referred to, and if (FLAGST) OLD = 1 (at the time of previous routine execution, start control), normal operation is performed. Judgment is the first time of control transfer, and initializing closed loop correction I ISCI
Proceed to 1807. If (FLAGST) OLD = 0, proceed to S1810.

At S1807, it is determined whether or not the air conditioner switch 89 is ON. If it is ON, the process proceeds to S1808, and if it is OFF, S180
Go to 9.

When the flow advances to S1808, the backup RAM 50a
Learning value ACON when the air conditioner is ON stored in
Read Te closed loop correction I portion ISC _I a I initialized at I minute learning value ACONI during air conditioner ON, also, the process proceeds to S1809, closed loop correction I min ISC
_I is initially set to the I-value learning value ACOFFI when the air conditioner is OFF stored in the backup RAM 50a, and the process proceeds to S1810.

Each of the above-mentioned I-minute learning values ACONI, ACOFF
I is updated in a closed loop correction I-based learning value learning subroutine described later and stored at a predetermined address in the backup RAM 50a.
Only once immediately after 1 has changed from ON to OFF (from start-up control to normal control), the closed-loop correction I-minute ISC based on the I-minute learning value ACONI or ACOFFI learned during the previous engine operation according to the air conditioner operating state.
Initialize _I. This allows closed loop correction I
The minute ISC _I is immediately compensated, and the startability is improved.

Then, when the flow advances to S1810, the value of the closed / open loop control determination flag FLAGCL set in the closed / open loop control determination subroutine described above is referred to. If FLAGCL = 1 (closed loop control), the flow advances to S1811 to execute FLAGCL. = 0 (open loop control), the process proceeds to S181 without updating the correction amount ΔI described later.
Proceed to 2.

In S1811, it is determined whether the post-start correction is being performed (ISCSD ≠ 0) by referring to the value of post-start correction ISCSD. If ISCSD ≠ 0, the flow proceeds to S1813, and if ISCSD = 0, the flow proceeds to S1817. . In S1813, the cooling water temperature TW is compared with the set temperature TWAS [° C.]. If TW ≧ TWAS (warm-up completed), the flow proceeds to S1814, where TW <TWAS (during warm-up).
In the case of, go to S1817. In S1814, the vehicle speed VSP is compared with the set value VSAS [Km / h], and VSP <VSAS
If (stop), the process proceeds to S1815, and if VSP ≧ VSAS (running), the process proceeds to S1817.

[0286] Thereafter, the process proceeds when the closed-loop correction in the I min value obtained by adding the after-start correction ISCSD to ISC _I update the above-mentioned closed-loop correction I portion ISC _I to S1815 (IS
C _I ← ISC _I + ISCSD), the process proceeds to S1816, and the post-start correction ISCSD is set to 0 to the extent that the post-start correction ISCSD is shifted to the closed-loop correction I portion (ISC
SD ← 0), and proceed to S1817.

As shown in FIGS. 39A and 39B, when the open-loop control is shifted to the closed-loop control, the post-start correction ISCSD (ISCAS) is not shifted to the closed-loop correction ISC _I. Until the closed loop correction ISC _I converges, a step in the duty ratio ISCON occurs, and the engine speed NE fluctuates. As a countermeasure, it is conceivable to increase a correction amount ΔI described later. However, when the correction amount ΔI is extremely increased, convergence deteriorates and hunting occurs in the engine speed NE.

On the other hand, as shown in FIGS. 39 (c) and (d), when the predetermined condition is satisfied (TW ≧ TWAS and VS
P <VSAS), when the control is shifted from the open loop control to the closed loop control, the post-start correction ISCSD (ISCA
When S) is ISCSD ≠ 0, the correction ISCSD (IS
Since the CAS) and is shifted to the closed loop correction I portion ISC _I, closed loop correction I portion ISC by increments
_The compensation is made by _I , and the connection from the open loop control to the closed loop control is improved, and the fluctuation of the engine speed NE at this time is prevented.

Thereafter, when the process proceeds from S1811, S1813, S1814, or S1816 to S1817, the idling target engine speed NSE
The difference rotation ΔN between T and the engine speed NE is obtained (ΔN ←
NSET-NE), and proceeds to S1818 to determine whether the air conditioner switch 89 is ON. If ON, proceed to S1819; if OFF, proceed to S1820.

In S1819, the differential rotation ΔN and the set value N
IH3 (NIH3 <0), and if ΔN ≦ NIH3, the process proceeds to S1826, where the correction amount ΔI is set to the set value TIPTAH3.
(TIPAH3 <0) and (ΔI ← TIPTAH)
3) Go to S1845.

If ΔN> NIH3 in S1819, the process proceeds to S1821, and the differential rotation ΔN and the set value NIH2 are set.
(Where NIH3 <NIH2 <0), and ΔN ≦
In the case of NIH2, the process proceeds to S1827 and the correction amount ΔI is set to the set value TI.
PTAH2 (however, TIPTAH3 <TIPATAH2
<0> (ΔI ← TIPTAH2), and the process proceeds to S1845. If ΔN> NIH2, the process proceeds to S1822 and the differential rotation Δ
N and set value NIH1 (however, NIH2 <NIH1 <0)
When ΔN ≦ NIH1, the process proceeds to S1828, where the correction amount ΔI is set to the set value TIPTAH1 (where TIPTAH2 <
Set by TIPTAH1 <0) (ΔI ← TIPTAH
1) Go to S1845.

When it is determined in step S1822 that ΔN> NIH1 and the flow advances to step S1823, the difference rotation ΔN is compared with 0, and ΔN
If ≦ 0, proceed to S1829 and set the correction amount ΔI to the set value TIPTA
H (however, TIPTAH1 <TIPTAH, TIPAT
H = 0 [%]) (ΔI ← TIPTAH), and S184
Proceed to 5. If ΔN> 0, the process proceeds to S1824. S1824
When the process proceeds to step, the differential rotation ΔN and the set value NIL1 (where 0 <N
IL1), and if ΔN ≦ NIL1, the process proceeds to S1830, where the correction amount ΔI is set to the set value TIPTAL (however, TIPT
AH ≦ TIPATL) (ΔI ← TIPTA
L), proceed to S1845. If ΔN> NIL1, S182
Proceed to 5.

At S1825, the differential rotation ΔN and the set value NI
L2 (where NIL1 <NIL2), and ΔN ≦
In the case of NIL2, the process proceeds to S1831, and the correction amount ΔI is
L1 (however, TIPTAL <TIPTAL1) is set (ΔI ← TIPTAL1), and the process proceeds to S1845. Also, ΔN
If> NIL2, proceed to S1832 and set the correction amount ΔI to the set value TI.
PTAL2 (however, TIPTAL1 <TIPTAL2)
(ΔI ← TIPTAL2), and the process proceeds to S1845.

FIG. 40 shows the relationship between the correction amount ΔI and the difference rotation ΔN. As can be seen from the figure, if the differential rotation ΔN is small, the correction amount ΔI is set small. Thereby, the convergence of the engine speed NE to the idle target speed NSET is improved.

On the other hand, in S1818, the air conditioner switch 89
Is determined to be OFF and proceeds to S1820, the S1820, S183
3 to S1837, the differential rotation ΔN and the set values NIH3, N
IH2, NIH1, 0, NIL1, and NIL2 are compared in the same manner as described above, and it is determined in S1820 that ΔN ≦ NIH3 and S1
When the process proceeds to 838, the correction amount ΔI is set by the set value TIPRTH3 (where TIPRTH3 <0) (ΔI ← TIPRT).
H3), proceed to S1845. In S1833, it is determined that ΔN ≦ NIH2, and when the flow proceeds to S1839, the correction amount ΔI is set to the set value TIPRTH.
2 (however, TIPRTH3 <TIPRTH2 <0) is set (ΔI ← TIPRTH2), and the process proceeds to S1845.

In S1834, it is determined that ΔN ≦ NIH1, and S184
When the process proceeds to 0, the correction amount ΔI is set to the set value TIPRTH1 (however,
Set by TIPRTH2 <TIPRTH1 <0) (ΔI
← TIPRTH 1), proceed to S1845.

At S1835, it is determined that ΔN ≦ 0, and the routine proceeds to S1841, where the correction amount ΔI is set to the set value TIPRTH (however, TIPRTH
TH1 <TIPRTH, TIPRTH = 0 [%]) is set (ΔI ← TIPRTH), and the process proceeds to S1845.

In S1836, it is determined that ΔN ≦ NIL1, and S184
2, the correction amount ΔI is changed to the set value TIPRTL (however, T
(IPRTH ≦ TIPRTHL) (ΔI ← TIP
RTL), proceed to S1845.

In S1837, it is determined that ΔN ≦ NIL2 and S184
When the process proceeds to 3, the correction amount ΔI is set to the set value TIPRTL1 (however,
Set by TIPRTL <TIPRTL1 (ΔI ← TI
PRTL1), proceed to S1845. In S1837, ΔN> N
If it is determined that IL2 and the process proceeds to S1844, the correction amount ΔI is set to the set value TIPRTL2 (where TIPRTL1 <TIPRT1).
L2) (ΔI ← TIPRTL2), and the process proceeds to S1845.

Then, S1826 to S1832 or S183
8 to S1844, the process proceeds to S1845.
Closed loop correction I portion ISC _I The closed loop correction I portion ISC _I that of being stored in a predetermined address
Is updated with a value obtained by adding the correction amount ΔI set in any of the above S1826 to S1832 and S1838 to S1844 (ISCI ← I
SC _I + ΔI), the process proceeds to S1846.

FIG. 41 is a time chart showing the relationship between the fluctuation of the engine speed NE relative to the target idle speed NSET, the correction amount ΔI and the closed loop correction ISC _I.

[Elapsed time t0 to t1] The engine speed NE is set to the set value NIH3 with respect to the idle target speed NSET.
(ΔN ≦ NIH3), the engine speed N
In order to reduce E, the correction amount ΔI is set to the minimum set value TIPTAH
3 is set (S1826).

As a result, the closed loop correction I component IS
C _I is a low value by the set value TIPTAH3, correspondingly, the duty ratio ISCON for ISC valve 13
, The opening of the ISC valve 13 decreases, and the engine speed NE decreases.

[Elapsed time t1 to t2] Next, the differential rotation Δ
When N falls between the set values NIH3 and NIH2, the correction amount ΔI is set at the set value TIPTAH2 (S1827),
The closed loop correction ISC ISC _I is the set value TIPTA
It becomes even lower by H2.

[Elapsed time t2 to t3] Then, the differential rotation Δ
When N falls between the set values NIH2 and NIH1, the correction amount ΔI is set to the set value TIPAH1 (S1828), and the closed-loop correction I minute ISC _I is set to the set value TIPTHA.
One minute, the engine speed NE decreases. When the differential rotation ΔN falls between the set values NIH1 and 0, the correction amount ΔI is set at the set value TIPTAH (0 [%]) (S1829).
The minute ISC _I does not change.

Thereafter, the differential rotation ΔN is set to 0 and NIL1.
Is smaller than the set value TIPTAL (T
IPTAH ≦ TIPTAL is set (S1830).

[Elapsed time t3 to t4] Next, the differential rotation Δ
When N falls between the set values NIL1 and NIL2, the correction amount ΔI is set at the set value TIPTAL1 (S1831), and the closed-loop correction I minute ISC _I is set at the set value TIPT.
It becomes higher by AL1 minute.

[Elapsed time t4 to t5] Thereafter, when the engine speed NE becomes lower than the set value NIL2 with respect to the idle target speed NSET (ΔN> NIL2), the correction amount ΔI is set to the set value TIPTAL2 (S1832). , Closed loop correction I ISCI is equal to the set value TIPTAL2
Only get higher.

[Elapsed time t5 to t6] Also, the differential rotation ΔN
Is smaller than the set values NIL2 and NIL1, the correction amount Δ
I is set at the set value TIPTAL1 (S1831), and the closed loop correction I minute ISC _I is set at the set value TIPTAL1.
Only get higher.

Then, the differential rotation ΔN is equal to the set values NIL1 and N
Since the set values TIPTAL and TIPTAH are 0 [%] during the period between the values IH1 and IH1, the closed-loop correction ISC _I does not change.

[After the elapsed time t6] On the other hand, when the differential rotation ΔN falls between the set values NIH1 and NIH2, the correction amount ΔI
Is set at the set value TIPTAH1, and thereafter, the differential rotation Δ
N converges between the set values NIH1 and NIL1, and the correction amount ΔI is set to the set values TIPTAL and TIPTAH (both are 0
[%]), The closed loop correction I component ISC _I is constant.

In S1845, the closed loop correction I component I
After setting the SC _I, the process proceeds to S1846, (details below) closed loop correction I portion of the learning subroutine is executed.

Next, in S1847, the value of the normal control shift time discrimination count value COUNTSTI is referred to, and COUNTST
If I 場合 0 (within the set time LRNISS after start) S1848
The process proceeds to S1850 if COUNTSTI = 0.

In S1848, a preset warm-up completion judgment value LRNI for judging whether to restart the warm-up and the cooling water temperature TW.
If TW ≧ LRNITW (restart of warm-up), the flow proceeds to S1849, and if TW <LRNITW (engine is in a cold state), the flow proceeds to S1850. Proceeding to S1849, the closed loop correction I minute ISC _I is compared with the adjustment value IMINBL. If ISC _I ≤IMINBL, the flow goes to S1853 to change the closed loop correction I minute ISC _I to the lower limit value IMI.
Set with NBL and proceed to S1859.

On the other hand, if it is determined in S1849 that ISC _I > IMINBL, the flow advances to S1851 to compare the above closed-loop correction I component ISC _I with the upper limit value IMAXBL.
_{If I} ≧ IMAXBL, the process proceeds to S1854, where the closed loop correction I component ISC _I is set to the upper limit value IMAXBL, and the process proceeds to S1859. If ISC _I <IMAXBL, it is determined that the closed-loop correction I component ISC _I is within the allowable range (IMAXBL> ISC _I > IMINBL), and the process directly proceeds to S1859.

Also, S1847 or S1848 to S185
0, the closed loop correction I
_I is compared with a value (lower limit value) obtained by subtracting the basic characteristic value ISCTW set in the basic characteristic value setting subroutine from the duty limit lower limit value IINCL set in the aforementioned ISC valve control main routine, and ISC _I ≤ ( IMIN
In the case of CL-ISCTW, the process proceeds to S1855, and the closed-loop correction ISC _{I is set} to the lower limit (IMINCL-IS).
CTW) (ISC _I ← IMINCL-ISCTW),
Proceed to S1859.

In S1850, ISC _I > (IMINCL−
In the case of (ISCTW), the process proceeds to S1852, where the closed loop correction amount ISC _I is compared with a value (upper limit value) obtained by subtracting the basic characteristic value ISCTW from the duty limit upper limit value IMAXCL set in the ISC valve control main routine. ISC
_{If I} ≧ (IMAXCL−ISCTW), proceed to S1856,
The closed loop I portion ISC _{I is set} to the upper limit (IMA
Set with (XCL-ISCTW) (ISC _I ← IMAXCL-IS
(CTW), and proceed to S1859. In S1852, ISC _I <(IMAXCL
-ISCTW), the closed loop correction I
Min ISC _I is within the allowable range ((IMINCL-ISCTW) <IS
It is determined that C _I <(IMAXCL−ISCTW)), and the process proceeds directly to S1859.

Duty ratio I for ISC valve 13
The majority of SCON is the basic characteristic value ISCTW, and the lower limit value for the correction term other than the basic characteristic value ISCTW is set by subtracting the basic characteristic value ISCTW from the duty limit lower limit value IMINCL.
Is subtracted from the basic characteristic value ISCTW to set the upper limit value.

However, <1> after starting, a predetermined time LRNIS
If it is within S [sec] (S1847), and <2> the set value LRNI for judging whether or not the cooling water temperature TW and the warm-up are restarted.
If TW is greater than or equal to LRNITW (S1848), it is determined that warm-up has been restarted, and IMINBL ≦ ISC _I ≦ IMAXBL regardless of open-loop or closed-loop control.

When the control is shifted to the normal control at the restart of the warm-up, when the closed-loop correction ISC _I is initially set (S1808 or S1809), the closed-loop correction ISC ISC _I has a small value (negative value). Learning value A)
CONI (when the air conditioner switch 89 is ON) or a learning value ACOFFI (when the air conditioner switch 89 is OFF)
If it is updated at (F), the engine speed NE will decrease, and if it is significant, it will stall. Therefore, the upper limit value and the lower limit value are set to the set values IMINBL and IMAX, respectively.
As the BL, the upper limit and the lower limit of the closed loop correction ISC ISC _I are shifted up to improve the restartability (see FIG. 41 (c)).

On the other hand, if it is determined in step S1810 that FLAGCL = 0 (open loop control) and the flow advances to step S1812, the cooling water temperature TW and the set value TWCL [for determining whether the cooling water temperature TW during open loop control is low water temperature] are determined. ° C] and T
If W ≦ TWCL, the process proceeds to S1857, and if TW> TWCL, the process proceeds to S1847 described above.

[0322] Proceeding to S1857 refers to the value of closed-loop correction I portion ISC _I, the process proceeds to S1858 case of ISC _I <0, after the above-mentioned closed-loop correction I portion ISC _I is set to 0 (ISC _I ← 0) Then, proceed to S1859. Also, ISC
_{When I} ≧ 0, the process proceeds to S1847.

As described above, during open loop control (FL
When the cooling water temperature TW of AGCL = 0 is low (TW ≤ TWCL)
) And the closed loop correction ISC _I is negative (ISC _I <0), the closed loop correction ISC _I is set to 0. (ISC _I
← 0). That is, when the closed-loop correction I component ISC _I set by the learning value ACONI or ACOFFI described later is on the negative side, the duty ratio ISCON decreases, and the opening degree of the ISC valve 13 decreases and the engine speed NE decreases. In order to prevent this, the lower limit value of the closed-loop correction ISC _I set by the learning value ACONI or ACOFFI immediately after the starter switch 61 shifts from ON to OFF (start-up control → normal control). It is set to 0.

Then, S1853 to S1856 or S185
When the process proceeds to S1859 from any one of the steps 8, the previous start / normal control discrimination flag (FLAGST) to be used in the next routine stored at a predetermined address in the RAM 50 with the current start / normal control discrimination flag FLAGST value ) Update the OLD value ((FLAGST) OLD ← FLAGST) and exit the routine.

(Closed Loop Correction I Minute Learning Subroutine) FIG. 26 shows the closed loop correction I correction subroutine executed in the closed loop correction I minute update procedure (see S1846).
This is a minute learning subroutine.

First, it is determined in S1901 to S1908 whether the learning condition is satisfied.

That is, in S1901, the cooling water temperature TW is compared with the warm-up completion judgment value LRNITW [° C.], and TW ≧ L
If RNITW (engine warm-up completed), proceed to S1902, if TW <LRNITW (engine cold), S1
Proceed to 913.

In S1902, the value of the power steering correction value ISCPS is referred to. If ISCPS = 0 (the power steering turning angle is small), the flow proceeds to S1903, and if ISCPS ≠ 0, the flow proceeds to S1913.

In S1903, it is determined whether the air conditioner switch 89 is OFF. If it is OFF, the flow proceeds to S1904, and if it is ON, the flow proceeds to S1905.

In S1904, the radian correction value ISC is set.
Referring to the value of RA, ISCRA = 0 (radiator fan 62
Is OFF), proceed to S1905, if ISCRAS ≠ 0
Proceed to S1913.

Then, S1903 or S1904 to S1905
When the process proceeds to, the value of the acceleration / deceleration correction DSHPT is referred to, and DSHPT = 0.
In the case of, the process proceeds to S1906, and in the case of DSHPT ≠ 0, the process proceeds to S1913.

At S1906, the dashpot correction value DH
Referring to the value of ENB, if DHENB = 0, that is, if it is determined that DSHPT = 0 and DHENB = 0 and it is determined that the engine is in the idling steady state, the flow proceeds to S1907, and DHENB ≠
If it is 0, the process proceeds to S1913.

In S1907, the closed loop correction I
Referring to the correction amount ΔI of the minute ISC _I , if ΔI = 0 (the state in which the engine speed NE converges within the allowable range of the idle target speed NSET), proceed to S1908, and if ΔI ≠ 0, proceed to S1913. .

In S1908, the set value LRISCT corresponding to the predetermined time is compared with the count value COUNTISCI of the learning condition satisfaction determination counter to determine whether or not the state in which learning is possible has continued for a predetermined time or more.
If ISCI ≧ LRISCT, it is determined that the learning condition is satisfied and S1
Continue to 909. If COUNTISCI <LRISCT, the process proceeds to S1910, where the count value COUNTISCI is counted up (COUNTISCI ← COUNTISCI + 1), and the routine exits.

On the other hand, if the flow proceeds to S1909, it is determined whether or not the air conditioner switch 89 is ON. If the air conditioner switch 89 is ON, the flow proceeds to S1911 and the I-part learning value ACONI stored at a predetermined address of the backup RAM 50a when the air conditioner is ON is closed loop at the present time. updated with the value of the correction I portion ISC _I (AC
ONI ← ISCI), and the process proceeds to S1913. S191 when OFF
2 and the I-minute learning value ACOF when the air conditioner is OFF stored at a predetermined address of the backup RAM 50a.
FI is the current closed-loop correction ISC ISC
Update with the value of _I (ACOFFI ← ISC _I ) and proceed to S1913.

Then, S1901, S1902, S1904 to S1907, S1
When the process proceeds to S1913 from 911 or S1912, the count value COUNTISCI is cleared (COU
NTISCI ← 0), exits the routine.

[0337] Incidentally, as shown by the broken line in FIG. 42 (a), when not using I component learning value ACONI or ACOFFI when setting the closed loop correction I portion ISC _I, via the open-loop control from the start control Therefore, a difference occurs before the control is shifted to the closed loop control.
As a result, as indicated by the broken line in FIG. 42 (b), the initial explosion occurs, but does not easily transition to the complete explosion, and the transition from the start control to the open loop control has a slight rise in the engine speed NE. Occurs.

On the other hand, as shown by the solid line in FIG. 42 (a), the difference from the start control to the transition to the closed loop control is obtained by adding the I component learning value ACONI or ACOFFI to the closed loop correction I. Improved,
As shown by the solid line in FIG. 42 (b), the operation immediately shifts from the first explosion to the complete explosion, so that the engine speed NE rises smoothly and the startability is improved.

[0339]

As described above , according to the first aspect of the present invention, it is determined whether the throttle valve is fully closed or open.
When the throttle valve is open, the throttle valve opening
The acceleration / deceleration correction value is set in proportion to
Compare the correction value with the previously set acceleration / deceleration correction value,
If the fixed acceleration / deceleration correction value is
In this case, the acceleration / deceleration correction value set this time is set as the acceleration / deceleration correction value.
I do. Also, the current acceleration / deceleration correction value is
If the value is smaller than the correction value,
Subtract the preset weight loss value from the
Therefore, when the opening of the throttle valve increases,
As the acceleration / deceleration correction value increases, the ISC valve opening
It is increased in proportion to the increase of the throttle valve opening,
The throttle valve opens when the throttle valve closes.
Opening of the ISC valve can be secured in proportion to the temperature
Then closes due to a decrease in the throttle valve opening.
After shifting the valve, adjust it until the throttle valve is fully closed.
The speed correction value is the reduction value regardless of the throttle valve closing speed.
Gradually decreases by Therefore, during acceleration or deceleration or
Immediately after the throttle valve suddenly closes after the engine is blowing
However, always accurately check the intake air volume with the ISC valve.
Can be maintained, the sudden decrease in intake pipe pressure is suppressed,
Fuel attached to the wall is supplied to the combustion chamber as the amount of air decreases sharply
Of air-fuel ratio over-rich due to
And the air-fuel ratio exceeds immediately after the throttle valve is suddenly closed.
Prevent misfires and abnormal combustion caused by rich
Qi emissions can be improved. Also, the slot
Acceleration / deceleration when transitioning from a torque-open state to a throttle-closed state
Correction value is set to a value corresponding to the opening of the rottle valve
Therefore, when the throttle is closed,
A so-called dashpot that buffers sudden drops in intake air volume
Period can always be obtained properly and the throttle valve
Immediately after closing, the ISC valve always sucks properly.
As the amount of incoming air is secured, the engine speed may drop sharply.
Engine stalling can be reliably prevented. On the other hand,
When the throttle valve is fully closed, set the arc according to the operating conditions.
Judgment threshold obtained by adding the offset value to the target idle speed
Comparing the value and the engine rotational speed, engine rotational speed is determined
If the value exceeds the threshold, the above acceleration /
Since the correction value is gradually reduced by the first set value,
The engine speed is idle after the fully closed
Acceleration / deceleration correction until it drops to near the target rotation speed
The rate of decrease of the value is set relatively large by the first set value
The intake air is reduced by the ISC valve opening reduction rate.
Idle target for engine speed early due to reduced fuel consumption
It is possible to converge on the rotation speed. And acceleration / deceleration correction
When the value reaches the hold value, the acceleration / deceleration correction value is
Maintain until the gin rotation speed falls to the judgment threshold.
As a result, the ISC valve opening
The controllability can be improved by suppressing the decrease. That
Later, the engine speed is determined based on the decrease in engine speed.
When the value falls below the threshold value, the acceleration / deceleration correction value becomes zero.
At a second set value smaller than the first set value.
Gradually until the acceleration / deceleration correction value becomes zero.
Performs open loop control and at least engine temperature
Add the acceleration / deceleration correction value to the basic characteristic value set based on the degree
To set the control amount for the ISC valve,
The engine speed falls below the judgment threshold and the idle target speed
Until it reaches, the control set using the acceleration / deceleration correction value.
The reduction rate of the control amount becomes smaller by the second set value, and the ISC
The rate of decrease in the opening of the lube also decreases. This allows the engine
Engine speed when the speed approaches the idle target speed
The number of drops is reduced, preventing stalling and
To improve the convergence stability of the engine speed to the idle target speed
Can be up. Therefore, the engine speed
Improves convergence to target speed and stability
Can significantly improve idle speed controllability.
Can be Then, at least the acceleration / deceleration correction value is zero.
Feedback from open loop control when
Control is transferred to the ISC valve by acceleration / deceleration correction.
Engine speed and idle from open loop control
To feedback control by comparison with target speed
Eliminate the step in the control amount of the ISC valve in the running process
Can be feedback from open loop control
The connection to the control can be made smooth. to this
The engine with the sudden change of the control amount for the ISC valve
To improve idle speed controllability by preventing fluctuations in engine speed.
Ru can be improved.

According to the second aspect of the present invention, the throttle
Judge whether the valve is fully closed or open, and open the throttle valve
At this time, the dashpot correction value is set to zero. Also,
When the throttle valve is fully closed,
Discrimination speed set to a value higher than the idle speed
Compare engine speed with engine speed to determine engine speed
When the engine speed drops below the
Initialize the dashpot correction value accordingly. And
Engine speed reduction speed falls below a preset value
Until the engine speed decreases,
Since the dashpot correction value is gradually reduced,
While matching the deceleration correction and the dashpot correction,
The dashpot correction using the
Throttle valve fully closed according to engine speed drop
Always give the opening reduction rate of the ISC valve properly after the transition
be able to. As a result, when the throttle valve suddenly closes
In addition, the ISC valve accurately reduces the sudden decrease in intake air volume.
Against the engine stall due to a drop in engine speed.
It can be reliably prevented. And the engine speed
Is below the discrimination speed set near the idle speed.
When the engine speed drops, a dash
Initialize the pot correction value, and then set the engine speed low.
Until the lower speed drops below the preset value,
Dashpot supplement with decreasing engine speed
Since the positive value is set to decrease gradually, the engine speed is low.
By directly controlling the ISC valve opening according to the lower speed,
In the process of converging the engine speed to the target idle speed
Engine speed fluctuations,
Further convergence of engine speed to idle target speed
Can be improved. After that, the engine speed
Dashpot correction when the drop rate falls below the set value
The value is gradually reduced by a small value until it reaches zero.
You. And until the dashpot correction value becomes zero
In the meantime, perform open loop control and at least
The above dash point is added to the basic characteristic value set based on the temperature.
Set the control amount for the ISC valve by adding the correction value
The engine speed approaches the idle target speed.
The speed of decrease in engine speed
The engine speed can be adjusted to the idle target speed
The convergence stability can it to significantly improved. And small
At least when the dashpot correction value reaches zero.
The transition from pun loop control to feedback control
The dashpot correction allows the
Engine speed and idle target times from open loop control
In the transition process to feedback control by comparison with the number of turns
In order to eliminate the step in the control amount of the ISC valve,
From open loop control to feedback control
Connection can be made smooth. This allows I
Engine speed due to sudden change in control amount for SC valve
To prevent idle fluctuations and improve idle speed controllability.
be able to. According to the third aspect of the present invention, acceleration / deceleration compensation is provided.
When setting a positive value, the engine when the throttle opening decreases
The speed at which the engine speed decreases decreases the power between the engine and the transmission.
Power transmission is interrupted more than in the driving range where transmission is performed.
Is faster in the P and N ranges where no load is applied
Correspondingly, in the case of the P and N ranges, the traveling range
If the offset value is set to a higher value than when
Both are proportional to the throttle opening when the throttle valve is opened
The acceleration / deceleration correction value, the weight loss value, and the
The first set value is set to a large value.
In addition to the effects of the invention described in item 1,
And can give the same or almost the same control characteristics.
You. Therefore, regardless of the range of the transmission,
To prevent engine stalling when the throttle valve is suddenly closed.
In addition, the convergence of the engine speed to the idle target speed and
It is possible to achieve both stability improvement and
It is possible to improve the controllability of the dollar rotation speed,
Wheeling can be significantly improved.

[Brief description of the drawings]

1 and 2 are flowcharts showing an ISC valve control procedure.

FIG. 2

FIG. 3 is a flowchart illustrating a correction value setting procedure.

FIG. 4 is a flowchart showing a basic characteristic value setting procedure.

FIG. 5 is a flowchart showing a procedure for setting an idle target rotation speed;

FIG. 6 is a flowchart showing a closed / open loop control determination procedure.

FIGS. 7 and 8 are flowcharts showing an air conditioner correction value setting procedure.

FIG. 8

FIG. 9 is a flowchart showing an air conditioner correction learning procedure when the air conditioner switch is turned from OFF to ON.

FIG. 10 is a flowchart showing an air conditioner correction learning procedure when the air conditioner switch is turned on → off.

FIGS. 11 and 12 are flowcharts showing a procedure for setting an AT vehicle traveling range correction value.

FIG. 12

13 and 14 are flowcharts showing an acceleration / deceleration correction setting procedure.

FIG. 14

FIG. 15 is a flowchart showing a dashpot correction value setting procedure.

FIG. 16 is a flowchart showing a procedure for updating a dashpot correction value.

FIG. 17 is a flowchart showing a procedure for setting a radial fan correction.

FIG. 18 and FIG. 19 are flowcharts showing a power steering correction value setting procedure.

FIG. 19

FIG. 20 is a flowchart showing a procedure for setting an air conditioner clutch correction value.

FIG. 21 is a flowchart showing a procedure for setting a correction initial value after starting.

FIG. 22 is a flowchart showing a post-start correction setting procedure.

FIGS. 23 to 25 are flowcharts showing a closed-loop correction I component updating procedure.

FIG. 24

FIG. 25

FIG. 26 is a flowchart showing a closed-loop correction I-minute learning procedure;

FIG. 27 is a schematic diagram of an engine control system.

FIG. 28 is a configuration diagram of a control device.

FIG. 29 is a time chart showing a relationship among an air conditioner switch, an air conditioner correction value, and an engine speed.

FIG. 30 is a time chart showing a relationship between a traveling range or N and P ranges, an AT vehicle traveling range correction, and an engine speed.

FIG. 31 is a time chart showing a relationship among an idle switch, throttle opening, acceleration / deceleration correction, and engine speed.

FIG. 32 is a time chart showing a relationship among an idle switch, an engine speed, and a dashpot correction value.

FIG. 33 is a time chart showing the relationship between radiator fan ON / OFF and radiator correction.

FIG. 34 is a time chart showing hysteresis at the time of setting the idling rotation speed.

FIG. 35 is a time chart showing a relationship between a power steering switch, a power steering correction value, and an engine speed.

FIG. 36 is a time chart showing a relationship among the capacity of an air conditioner switch, an air conditioner clutch relay, an air conditioner compressor, an air conditioner clutch correction value, and an engine speed.

FIG. 37 is a time chart showing changes in post-start correction.

FIG. 38 is a time chart showing a change in duty ratio.

FIG. 39 is a time chart showing a shift of a post-start correction value to a closed loop correction I portion.

FIG. 40 is an explanatory diagram showing the relationship between the correction amount for the closed loop correction I and the difference rotation.

FIG. 41 is a time chart showing the relationship between the engine speed, the amount of correction for closed loop correction I, and the amount of closed loop correction I;

FIG. 42 is a time chart showing a use state of a learning value for closed loop correction I;

[Explanation of symbols]

6e Air bypass passage 11d, 11e Throttle valve 13 ISC valve DDASH Decrease value DDSH1 First decrease value (first set value) DDSH2 Second decrease value (second set value) DHEBN Dashpot correction value DHEKN Discrimination speed DNES1 setting value DDFEB setting value (setting minute value) DSHPT acceleration / deceleration correction value ISCON duty ratio (control amount) ISCTW basic characteristic value NE engine speed NST idle target speed NDASH offset value NDOWN engine speed reduction amount per set time ( En
Gin rotation speed) RDASH Dashpot holding value (holding value) THV Throttle valve opening TW Engine temperature (cooling water temperature)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-81941 (JP, A) JP-A-63-100244 (JP, A) JP-A-2-91444 (JP, A) JP-A 61-1986 219430 (JP, A) JP-A-59-136541 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/08 315 F02D 41/12 315

Claims (3)

(57) [Claims] When the throttle valve is fully closed, the engine is turned on.
Depending on the result of comparing the speed and idle target speed,
Installed in the air bypass passage that bypasses the throttle valve
Control of the control amount for the selected ISC valve
When the throttle valve is open, open loop control
And adjust the acceleration / deceleration correction value in proportion to the throttle opening.
At the time of transition from opening the throttle valve to fully closed
Then, the acceleration / deceleration correction value is gradually decreased by a set value,
Basic characteristic value set at least based on engine temperature
To the ISC valve by correcting the
ISC valve control method for the engine to set the control amount
Oite, the procedure throttle valve to determine whether the fully closed or open valve, when the throttle valve opening, the ratio of the throttle valve opening
For example, by setting the acceleration / deceleration correction value,
Value and the previously set acceleration / deceleration correction value.
If the acceleration / deceleration correction value is equal to or greater than the acceleration / deceleration correction value set previously,
Set the acceleration / deceleration correction value set this time as the acceleration / deceleration correction value,
The current acceleration / deceleration correction value is
If it is smaller, it will be set in advance from the previously set acceleration / deceleration correction value.
The procedure for setting the acceleration / deceleration correction value by subtracting the weight loss value, and setting the throttle valve fully closed according to the operating state
Judgment by adding the offset value to the target idle speed
Value and the engine speed to determine the engine speed.
If the value exceeds the fixed threshold, the above
The speed correction value is gradually reduced by the first set value,
When the rotation speed falls below the threshold, the acceleration / deceleration
A value smaller than the first set value until the positive value becomes zero
And a procedure for gradually decreasing the acceleration and deceleration correction value until the above-mentioned acceleration / deceleration correction value becomes zero.
Control at least based on the engine temperature.
Add the acceleration / deceleration correction value to the basic characteristic value
Set the control amount for the valve and at least correct acceleration / deceleration
Move to feedback control when the value becomes zero.
ISC valve for an engine, comprising:
Control method. 2. When the throttle valve is fully closed, the engine
Depending on the result of comparing the speed and idle target speed,
Interposed of the air bypass passage bypassing the Ttorubarubu
Control of the control amount for the selected ISC valve
When the throttle valve is open, open loop control is
And the throttle valve has shifted from open to fully closed.
The dashpot correction value, and then
The Schpot correction value is gradually reduced by the set value,
At least the basic characteristic value set based on the engine temperature
Corrected by the dashpot correction value to the ISC valve
ISC valve control method to set the control amount for the engine
The method for determining whether the throttle valve is fully closed or open , and the method for determining the dashpot correction value when the throttle valve is open.
When the throttle valve is fully closed and the throttle valve is fully closed,
Discrimination speed set to a value higher than the idle speed
Compare engine speed with engine speed to determine engine speed
When the engine speed drops below the
Initially set the dashpot correction value according to the
Until the rotation speed reduction speed falls below the preset value
During the interval, the dash
A step-by-step setting of the engine correction value, and when the engine speed reduction speed falls below the set value,
Set the dashpot correction value to a small value until it reaches zero.
Between the gradual decrease procedure and the dashpot correction value of zero.
Perform open loop control and determine at least
Dashpot correction value to the basic characteristic value
Is added to set the control amount for the ISC valve.
At least when the dashpot correction value becomes zero.
And a procedure for shifting to a feedback control . 3. The automatic transmission is shifted to P and N ranges.
To determine whether the vehicle has been shifted to the driving range
The offset value is set to a higher value in the P and N ranges than in the travel range, and the acceleration / deceleration correction value set in proportion to the throttle opening when the throttle valve is opened. The ISC valve control method for an engine according to claim 1, wherein the reduced value and the first set value are set to large values.