JPH07103043A - Idel speed control method - Google Patents

Abstract

PURPOSE:To accurately calculate a learning correction value of an intake air amount control valve by suppressing quick increasing a power generating quantity, and further deciding an electric load for whether provided or not based on a current value of a generator or the like, to also calculate a value reduced corresponding to the electric load, when the electric load is applied during idle operation. CONSTITUTION:In an intake pipe.2 of an engine 1, a throttle valve 2 and a bypass passage 4 of bypassing this valve are arranged. An ISC valve 5 for controlling an idle speed is arranged in the bypass passage 4. Further in an engine control unit 7, based on output signals from various sensors and switches for detecting an operating condition of the engine 1, the ISC valve 5 and an alternator (generator) 8 are controlled. Here during idle operation, when an electric load is applied, quick generating a generating quantity in the generator 8 is suppressed, and further based on each current value of the generator 8 and a battery, whether the electric load is provided or not is decided. A value corresponding to the electric load is calculated to be reduced, to accurately calculate a learning correction value of the ISC valve 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an idle speed of an internal combustion engine.

[0002]

2. Description of the Related Art There is known an idle speed control method in which an intake air amount is feedback-controlled in accordance with a difference between a target idle speed and an actual engine speed to maintain the idle speed at a target speed. There is. In this control method, if the feedback control amount becomes large due to deterioration of engine performance or the like, there is a possibility that delay of control response or hunting of idle speed may occur. Therefore, learning is performed and the learning correction value is obtained when the operation of the engine during the feedback control is stable. Then, the learning correction value is added to the target opening degree corresponding to the target rotation speed to determine the intake air amount, so that the feedback control is smoothly switched to the open loop control.

On the other hand, when an electric load is applied during idle rotation, the electric load is corrected to prevent the idle speed from decreasing. To correct the electric load, the amount of power generated by the alternator is detected, and the intake air amount control valve (ISC valve) provided in the bypass passage of the throttle valve of the intake passage is opened according to the magnitude of the generated current value to intake air. Increase the amount. At this time, the control of the intake air amount control valve regulates the increasing speed of the power generation amount of the alternator when the electric load is applied.

[0004]

However, the learning correction value cannot be accurately obtained if an electric load is applied during learning during feedback control of idle rotation. The present invention has been made in view of the above points, and when the electric load is applied during the calculation of the learning correction value of the target opening of the intake air amount control valve, the value corresponding to the applied electric load is subtracted. However, it is an object of the present invention to provide an idle speed control method for accurately obtaining a learning correction value.

[0005]

In order to achieve the above object, according to the present invention, a target opening degree of an intake air amount control valve for adjusting an intake air amount of an internal combustion engine and a target rotational speed during idle operation are set. Set, determine whether the operating state of the internal combustion engine is a specific operating state that allows feedback control of the idle rotational speed, and compare the target rotational speed with the actual rotational speed in the specific operating state to determine the actual rotational speed. Control the intake air amount control valve so as to approach the target number of revolutions and calculate learning value data for reducing or canceling the difference between the actual opening and the target opening amount, and the intake air amount control valve when not in a specific operating state. In the idle speed control method for performing open loop control of the opening of the control opening to a control opening set based on the target opening and learning value data, the field current of the generator driven by the internal combustion engine when an electric load is applied. Control To limit the sudden increase in the amount of power generation, calculate the generated current value based on the operating state of the generator, and calculate the battery consumption current value based on the battery state to calculate from the generated current value and the battery consumption current value. The presence or absence of an electric load is determined based on the electric load current value, and the intake air amount control valve in the open loop control is based on the generated current value or the electric load current value when the occurrence of the electric load is determined. The control opening is controlled to reflect the set electric load compensation opening data, and the learning value is calculated based on the generated current value when it is determined that an electric load is generated. The learning value data for reducing or canceling the difference between the actual opening and the sum of the target opening and the operating opening data is calculated.

[0006]

When an electric load is applied during idle operation of the engine, the field current of the generator driven by the engine is controlled to limit a sudden increase in the amount of power generation, and power is generated based on the operating state of the generator. Calculate the current value. At the same time, calculate the current consumption value of the battery based on the state of the battery,
The presence or absence of an electric load is determined based on the electric load current value calculated from the generated current value and the battery consumption current value. Then, in the open loop control, the intake air amount control valve is set to a control opening that reflects the electric load compensation opening data set based on the generated current value or the electric load current value when the occurrence of the electric load is determined. Learning to reduce or cancel the difference between the sum of the opening data for electric load compensation set based on the generated current value and the target opening and the actual opening when the occurrence of an electric load is determined. Calculate value data. As a result, learning based on the battery state quantity used for electric load detection in electric load correction is avoided, and a decrease in rotation speed is also prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an outline of an engine idle speed control system to which the method of the present invention is applied. A throttle valve 3 and a bypass passage 4 that bypasses the throttle valve 3 are provided upstream of an intake pipe 2 of the engine 1. And the bypass passage 4 has idle speed control (ISC)
Intake air amount control valve (hereinafter referred to as "ISC valve")
5 are provided. The ISC valve 5 controls the opening / closing of the bypass passage 4 by, for example, a stepper motor to control the amount of air taken into the engine 1 during idle operation.
The engine 1 may be the above-described cylinder deactivated engine, or an engine of a type in which a stratified vertical vortex of air-fuel mixture and air is formed in the cylinder to perform lean combustion.

The engine control unit 7 includes a water temperature sensor, a crank angle sensor, an air conditioner switch, a power steering fluid pressure switch, an ignition switch ST, an idle switch and the like, as well as a transmission neutral switch, an electric load switch and a vehicle speed sensor. The signal and the signal from the FR terminal of the alternator (generator) 8 are input to control the continuity between the G terminal of the alternator 8 and the ground during idle operation to control the output current of the alternator 8 and also according to the load. The ISC valve 5 is controlled to correct the idle speed.

FIG. 2 shows a charging system of the alternator 8 of FIG. 1. The alternator 8 incorporates a rectifier circuit 10, an auxiliary diode 11, and a voltage regulator 12, and each output terminal of the stator coil 13 has a rectifier circuit. 1
It is connected to the B terminal via 0 and is also connected to the T terminal of the voltage regulator 12 and one end of the field coil 14 via each auxiliary diode 11. The other end of the field coil 14 is connected to the F terminal of the voltage regulator 12.

The voltage regulator 12 is composed of a battery voltage detection type IC circuit for detecting a voltage by a battery. The L terminal is connected to the T terminal and the E terminal via a series circuit of resistors R1 and R2. , S terminal is resistor R
It is connected to the E terminal through a series circuit of 5 to R7. The collector of the transistor Tr2 is connected to the L terminal via the resistor R3, the emitter is connected to the E terminal, and the base is connected to the connection point between the resistors R1 and R2 via the Zener diode ZD1 and the diode D1 and the resistor R4. Via the capacitor C1 to the collector, and the connection point between the Zener diode ZD1 and the diode D2 is connected to the connection point between the resistors R5 and R6.

The collector of the power transistor Tr1 is F
The terminal and the flywheel diode DF to the T terminal, the diode D3 to the FR terminal, and the base
The collector and the emitter of the transistor Tr2 are connected to the E terminal, respectively. The collector of the transistor Tr3 is
The emitter is connected to the E terminal at the connection point between the resistors R6 and R7, and the base is connected to the G terminal via the resistor R8. G
The terminal is connected to the L terminal via the resistor R9. Further, the F terminal is connected to the FR terminal through the diode D3, and the E terminal is grounded together with the ground terminal of the rectifier circuit 10.

The B terminal of the alternator 8 is connected to the battery 1
5 + terminal and each electric load (not shown), the L terminal,
Via the parallel circuit of the charge lamp 16 and the resistor R10 and the ignition switch 17, the + terminal of the battery 15 and the S terminal are connected to the + terminal of the battery 15, respectively. The G terminal of the alternator 8 is connected to the terminal 7a of the engine control unit 7, and the FR terminal is connected to the terminal 7b.

Terminal 7 of engine control unit 7
a is connected to the collector of the transistor Tr4 via the resistor R11, the emitter of the transistor Tr4 is grounded, and the base is connected to a control circuit (not shown). The terminal 7b is connected to the control circuit via a diode D4 and a resistor R12, and is connected to the diode D4 and the resistor R1.
The connection point with 2 is connected to the power supply + V via a resistor R13.

The operation will be described below. When the ignition switch 17 is turned on, the battery 15, the charge lamp 16, the field coil 14 of the alternator 8,
A current flows through the path of the power transistor Tr1, the charge lamp 16 is turned on, and the initial exciting current flows through the field coil 14. Auxiliary diode 1 at this start
1 output voltage, that is, the input voltage of the T terminal of the voltage regulator 12 is less than the specified voltage, and the transistor Tr2
Is off and the power transistor Tr1 is on.
When the engine starts and the alternator 8 rotates to start power generation, the T terminal becomes equal to the battery voltage, the charge lamp 16 is turned off, and the field current is supplied from the auxiliary diode 11 to the field coil 14 to generate power. Continuing, the generated current is output from the rectifier circuit 10 to the B terminal and supplied to an electric load such as a headlamp. Also,
The battery 15 is charged.

When the output voltage of the alternator 8 exceeds the specified voltage, the transistor Tr2 is turned on and the transistor Tr1 is turned off. As a result, the field current of the field coil 14 of the alternator 8 continues to flow through the flywheel diode DF because of the inductance.
The output current of the alternator 8 also decreases by this field current.

Due to this decrease in output current, the output voltage becomes
Although it slightly increases, it gradually decreases because the field current decreases, and when the specified voltage is reached, the transistor Tr2 is turned off and the power transistor Tr1 is turned on again.
By repeating such operations, the output voltage is controlled to the specified voltage. Therefore, the power transistor Tr1 is turned on,
Off will be repeated. And alternator 8
The magnitude of the output current is determined by the rate at which the power transistor Tr1 is turned on.

The voltage at the FR terminal of the alternator 8 becomes a low level (hereinafter referred to as "L") when the power transistor Tr1 is on, and the power transistor Tr1 is turned on.
High level (hereinafter referred to as "H") when is off
Becomes Therefore, the output current of the alternator 8 can be detected by calculating the rate at which the FR terminal is at L. That is, the FR terminal of the alternator 8 is
The energization state (ON / OFF) of the field coil 14 is input to the engine control unit 7, and the engine control unit 7 detects the output current of the alternator 8 by this ON / OFF signal, and I
The SC valve 5 is driven to control the amount of air taken into the engine 1.

The engine control unit 7 controls the output current of the alternator 8 by duty-controlling the conduction between the G terminal of the alternator 8 and the ground. That is, the engine control unit 7 controls ON / OFF of the transistor Tr4 during idle operation to duty-control the conduction between the G terminal and the ground terminal of the alternator 8 and limits the output current of the alternator 8. The off-duty of the G terminal at this time is controlled to be the same as the on-duty of the power transistor Tr1 of the voltage regulator 12. The transistor Tr4 is turned off,
There is no continuity between the G terminal of the alternator 8 and the ground (1
In the case of (00% duty), the transistor Tr3 is always conductive (ON), and when the S terminal of the alternator 8 reaches the first predetermined voltage (for example, 14.4V), the power transistor Tr1 is turned off and the field The magnetic current is cut off, power generation is stopped, and the output voltage of the alternator 8 is adjusted to the predetermined voltage.

When the transistor Tr4 is turned on and the G terminal of the alternator 8 is short-circuited to ground (0% duty), the transistor Tr1 is always turned off. In this case, the S terminal voltage of the alternator 8 is the second
When the predetermined voltage (for example, 12.3 V) is reached, the power transistor Tr1 is turned off. That is, the alternator 8 is
It is possible to issue an instruction to stop power generation (field current cut) from the outside, and the amount of power generation can be limited by setting the grounded duty of the G terminal. When the output voltage of the alternator 8 drops to the predetermined voltage, it is lower than the voltage of the charged battery 15, so that almost no current is supplied from the alternator 8.

Now, at the time of idling operation, when an electric load, for example, a head lamp is turned on, the consumption current increases sharply (arrow A in FIG. 9 (d)). This sudden increase in load current causes the battery voltage to drop momentarily before the amount of power generation increases (see FIG. 9).
(a)). Then, after the battery voltage drops, the alternator 8 operates so as to increase the power generation amount (see FIG. 9).
(e)). Therefore, the information on the battery voltage is the earliest with respect to the rapid increase in the electric load. And the decrease of the battery voltage is
It depends on the size of the electrical load. That is, the electric load is
When the battery voltage drops, a current value greater than the amount of power generated by the alternator 8 is requested.

The engine control unit 7 detects the battery voltage value, estimates and calculates the battery consumption current value from the deviation between the detected value and the preset value, and the calculated battery consumption current value and the alternator 8 The electric load current value is obtained from the sum of the generated current value. The power generation amount of the alternator 8 is obtained by the on-duty of the field coil 14 and the engine speed. And
The presence or absence of an electric load is determined based on the obtained electric load current value, the opening amount of the ISC valve 5 is determined, and the ISC valve 5 is controlled to increase the intake amount of the bypass passage 4 (Fig. 9 (c)). That is, when the expected load current value exceeds the predetermined value, the ISC valve 5 is opened accordingly and the air amount is increased quickly.

Immediately after the electric load is applied, the engine control unit 7 promptly detects the application of the electric load from the decrease in the battery voltage and opens the ISC valve 5 largely. On the other hand, the engine control unit 7
By increasing the power generation current value of the alternator 8 at a speed according to the increase of the intake air amount (FIG. 9 (e)), the load torque (power generation amount) and the output torque (intake air amount) are balanced.
As a result, the decrease in engine speed is reduced, and high idle stability is obtained against changes in electric load (Fig. 9).
(b)).

Next, with reference to the flow charts of FIGS. 3 to 7, an idling stabilizing method against a sudden increase in electric load during idling will be described. First, the signal level (L level) of the FR terminal of the alternator 8 is counted, and the duty driving of the G terminal will be described. In FIG. 3, the engine control unit 7 interrupts at a cycle of 0.25 ms, for example, by a timer interrupt or a crank pulse interrupt generated at every predetermined crank angle of the engine (step S1), and the signal level of the field terminal FR is L. If it is L, the count value of the FR counter is advanced by 1 (step S3), and the count value of the G counter is decremented by 1 (step S4). Then, it is determined whether or not the value of the G counter has become 0 or less (step S5), and when it is 0 or less, the G terminal is set to L (grounded) and the routine ends (step S6). When it is larger, G terminal is H (release)
Then, the routine is finished (step S7).

In the all-alternator 8, when the G terminal is L, the transistor Tr3 is always off (FIG. 2), and when the S terminal voltage reaches the second predetermined voltage, the power transistor Tr1 is off and the output is output. The voltage is adjusted to the predetermined voltage. When the G terminal is H, the transistor Tr3
Is always turned on, and when the S terminal voltage reaches the first predetermined voltage, the power transistor Tr1 is turned off and the output voltage is adjusted to the predetermined voltage.

Next, the calculation of the duty ratio of the field current flowing through the field coil 14, the estimation of the generated current value, the electric load current value, the judgment of the electric load, the G terminal duty drive, and the ISC electric load correction will be described. First, an interrupt is made in synchronization with the crank angle (step S10), and the previous FR duty ratio Dfold is stored in the memory (step S10).
11) The stroke cycle of the crankshaft is read (step S12), the present FR duty ratio Dfr is calculated based on the FR counter value of step S3 described above (step S13), and the FR counter is cleared (step S14). .

Dfr = FR counter count value × 0.25 ms / stroke cycle Next, the generated current Ialt of the alternator 8 is obtained from the map based on the calculated FR duty ratio Dfr and the engine speed Ne (step S15) (FIG. 5). ), And the electric load current value Iel is calculated (step S16). Ialt〓f [Ne, Dfr].

Then, the electric load current value Iel is calculated from the obtained alternator generated current value Ialt (step S16). Electric load current value = generated current value + battery consumption current value = f [Ne, Dfr] + Kamp · (Xvb-Vb) where f [] is a two-dimensional map based on engine speed Ne and alternator field duty Dfr The value Kamp represents the conversion coefficient, the value Xvb represents the reference voltage of the battery (for example, 14V), and the value Vb represents the battery voltage. However, the battery voltage Vb is the battery reference voltage Xvb
Higher than (Vb> Xvb), the electric load current value Iel
Is the alternator generated current Ialt.

After calculating the electric load current value Iel, it is determined whether or not a predetermined operating condition is satisfied (Xel> Xel1) (step S17). This operating condition is, for example, when all of the following conditions are satisfied. (1) Elapsed time after start ≥ XTWOIC (3 to 10 seconds), (2) Engine cooling water temperature ≥ X
WTFB, (3) idle switch ON, (4) A / C switch OFF, (5) generated current value> (XIELU / XIELL). Here, the value Xel1 represents the no-load current, the value XTWOIC represents the NF / B prohibition time after starting, and the value XWTFB represents the 0 2 F / B start water temperature.

When the predetermined operating condition is satisfied, the electric load current value Iel is equal to the no-load reference current value Xel1.
(For example, 10A) is determined (step S18), and when it is greater (Iel> Iel1), the electric load flag is turned on (step S19), and step S17.
If the predetermined operating condition is not satisfied, or if the determination result of step S18 is negative (N0), the electric load flag is turned off (step S20), and step S21
Proceed to (Fig. 6). In the determination of step S18, Iel
Since the value includes the Kamp. (Xvb-Vb) term, it is possible to speed up the detection of the presence or absence of an electric load that causes a large fluctuation in the idle speed. This step S21
At, the target FR duty ratio Dfrobj is calculated.

Dfrobj = min {Dfr, Dfrold + Xfrup} Then, as the target FR duty ratio Dfrobj, the present FR duty ratio Dfr and the previous FR duty ratio Dfrol are used.
The value obtained by adding the FR duty increase amount Xfrup to d is compared, and the smaller one is selected to suppress a sudden increase. Next, it is judged whether the engine is in the idle region (Ne
≦ Xneid), the process proceeds to step S23 when in the idle determination region, and step S23 when not in the idle region
In step 24, the G terminal duty ratio Dg is calculated.
Here, the value Xneid is an idle area determination value. Then, in step S23, the G terminal duty ratio Dg is calculated.

Dg (〓Dfrobj + Xgdb)
The value Xgdb is a dead zone value. In step S24, the G terminal duty ratio Dg (100%) is calculated. Here, the value Xgdb is a dead zone value. When the engine speed is in the idle range, the alternator 8
Is always duty-driven. Then, the calculated G terminal duty ratio Dg is converted into a counter value of the G counter and the routine is finished (step S25).

G counter = Dg × stroke cycle / 0.25 ms In the alternator 8, when the duty ratio Dg of the G terminal becomes, for example, 60%, the G counter value in step S4 described above is set to the value of the power generation amount of 60%. . And FIG.
By executing this routine every 0.25 ms, the G terminal is controlled and the power generation amount becomes 60%.

The target FR duty ratio Dfrobj is
It doesn't increase suddenly. That is, even if the FR duty ratio Dfr value suddenly increases this time, the target is only the amount obtained by adding the dead zone value Xgdb to the previous value Dfrold. Then, the amount obtained by adding the dead zone value Xgdb is set as the duty ratio Dg of the G terminal this time. For this reason, the duty ratio Dg of the G terminal gradually increases, and accordingly, the alternator power generation amount gradually increases.

Next, description will be made of a case where the electric load correction of the ISC valve opening degree is performed in a predetermined cycle (for example, 25 ms) in the ISC routine shown in FIG. 7 (step S30). First, the basic opening Pbase of the ISC valve 5 is calculated from the water temperature parameter map g [WT] (step S31), and the learning value Plearn is added to this basic opening Pbase to calculate the temporary target opening Pobjl of the ISC valve 5. Yes (step S32).

Bypass valve target opening degree Pobjl〓Pbase + Plearn Next, it is determined whether or not engine speed feedback control is being performed (step S33). The determination conditions are, for example, (1) the idle switch is on, (2) the vehicle speed is 0, (3) the air conditioner is switched and a predetermined time has passed, (4) immediately after the engine is started. (6) A predetermined time (for example, 3 seconds) has elapsed, (5) A predetermined period has elapsed since the engine speed decreased across the target idle speed + a predetermined speed (for example, 300 rpm), and (6) the electric load flag was turned on. This is when all the conditions such as the lapse of a predetermined time from the start of the open loop execution by are satisfied. Then, feedback control of the engine speed is not performed, that is, during open loop control,
It is determined whether or not the electric load flag is ON (step S34), and when the electric load flag is ON, step S
The provisional target opening degree Pobjl of the ISC valve 5 is added to the provisional target opening degree Pobjl of the ISC valve 5 calculated in step 32 to set the provisional target opening degree Pobjl of the ISC valve 5 (step S35), and the target opening degree of the ISC valve 5 is opened. The degree Pobj is updated to the provisional target opening degree Pobjl, and the previous target opening degree Pobjold is changed to the current target opening degree Pob.
It is updated to j (step S36).

Electric load correction amount 〓Kel ・ (Ialt-Xel2) ISC valve temporary target opening Pobjl〓Pobjl + Kel ・ (Ialt-
Xel2) Here, the value Xel2 is the electric load correction reference current value, and the value Kel
Is a conversion coefficient. When the electric load flag is on,
By adding the correction of Kel · (Ialt−Xel2), it is possible to prevent the idling speed drop due to the electric load application earlier.

The engine control unit 7 is an IS
The ISC valve drive signal is instructed so that the C valve 5 reaches the target opening Pobj (step S37), and the routine ends. If the determination result of step S34 is negative (NO), the process proceeds to step S36 without performing electrical load correction. When the determination result of step S33 is affirmative (YES), that is, when the engine speed feedback control is being performed, it is determined whether it is the operation timing for performing feedback control (step S40).

This determination is to determine whether or not a predetermined time has elapsed from the time when the drive signal was output to the ISC valve 5 last time, and the drive signal output to the ISC valve 5 should be separated by a predetermined time or more. This prevents control hunting. When it is not the time to perform the feedback control, the routine is ended, and when it is the time to perform the feedback control, the previous target opening Pobjold
In addition, the current target opening degree Pobj of the ISC valve 5 is calculated based on the value obtained by subtracting the current idle speed Ne from the target idle speed Nobj, and the previous target opening degree Pobjold is calculated.
To the target opening Pobj of this time (step S4
1).

ISC valve target opening Pobj〓Pobjold + Kfb
(Nobj-Ne) Pobjold = Pobj Next, it is determined whether or not a condition for updating the learning correction value of the ISC valve target opening is satisfied (step 42). This learning correction value update condition is, for example, (1) a certain time has elapsed after the idle speed feedback control was started,
(2) When the water temperature Tw is equal to or higher than a predetermined temperature (for example, 70 ° C.), (3) when a predetermined time has passed immediately after the engine is started, and the like. Then, when the update condition of the learning correction value is satisfied, it is determined whether or not the electric load flag is on (step S43), and when the electric load flag is on, the electric load correction amount according to the electric load is added to the ISC. The provisional target opening Pobjl of the valve 5 is corrected (step S
44).

ISC valve temporary target opening Pobjl = Pobjl + Kel
(Ialt-Xel2) Then, the temporary target opening Pobjl calculated in step S44 is subtracted from the target opening Pobj calculated in step S41 to calculate the difference Pcrnt (= Pobj-Pobjl) (step S45). Based on the difference value Pcrnt, the learning correction value (Ple
arn) is updated and the process proceeds to step S37 described above (step S46).

Plearn〓Plearn + (Pcrnt / KK)
(The value KK is a weighting factor) The value Pobj calculated in step S41 when the electric load flag is turned on naturally includes a correction amount due to the electric load, and the value Pobj is calculated as Kel · (Ialt−
By subtracting the Xel2) value, it is possible to eliminate the correction amount due to the electric load fluctuation from the learning correction value.

When the electric load flag is not turned on in step S43, the process proceeds to step S45 without correcting the electric load. If the learning update condition is not satisfied in step S42, the process proceeds to step S37.
In addition, when calculating the electric load correction amount in step S35, instead of the alternator generated current value Ialt, for example,
The electric load current value Iel may be used.

[0043]

As described above, according to the present invention, the occurrence of an electric load is immediately detected from the state of the battery and the state of the generated current while suppressing the sudden increase in the electric power generation load, and the intake air intake amount corresponding to the electric load is increased. It is possible to prevent a drop in the idle speed by executing the above immediately, and during learning execution, the learning value is obtained by excluding the factor due to the battery state detection that is unrelated to the torque originally applied to the engine. Therefore, there is an effect that erroneous learning can be avoided and a decrease in the engine speed during open loop control in which the learned value is reflected can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an idle speed control system to which the present invention is applied.

FIG. 2 is a circuit diagram showing an embodiment of a charging circuit of the alternator of FIG.

FIG. 3 is a flowchart showing a procedure for counting a signal level of a field terminal of the alternator of FIG. 2 and performing duty driving of a G terminal.

4 is a part of a flowchart showing a procedure for performing field duty ratio, generated current value, electric load current value calculation, electric load determination, and G terminal duty driving of the alternator of FIG.

5 is the rest of the flowchart of FIG.

6 is the rest of the flowchart in FIG.

FIG. 7 is a part of a flowchart showing a procedure for performing ISC electrical load correction.

8 is the rest of the flowchart of FIG.

FIG. 9 is a diagram showing an example of control characteristics during idling of an engine to which the control method according to the present invention is applied.

[Explanation of symbols]

 1 Engine 2 Intake Pipe 3 Throttle Valve 4 Bypass Passage 5 ISC Valve 7 Engine Control Unit 8 Alternator 10 Rectifier Circuit 12 Voltage Regulator 13 Stator Coil 14 Field Coil 15 Battery

[Procedure amendment]

[Submission date] October 13, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

When an electric load is applied during idle operation of the engine, the field current of the generator driven by the engine is controlled to limit a sudden increase in the amount of power generation, and power is generated based on the operating state of the generator. Calculate the current value. At the same time, calculate the current consumption value of the battery based on the state of the battery,
The presence or absence of an electric load is determined based on the electric load current value calculated from the generated current value and the battery consumption current value. Then, in the open loop control, the intake air amount control valve is set to a control opening that reflects the electric load compensation opening data set based on the generated current value or the electric load current value when the occurrence of the electric load is determined. Learning to reduce or cancel the difference between the sum of the opening data for electric load compensation set based on the generated current value and the target opening and the actual opening when the occurrence of an electric load is determined. Calculate value data. As a result, erroneous learning based on the battery state quantity used for electric load detection in electric load correction is avoided, and a decrease in rotation speed is prevented.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02D 45/00 340 C

Claims (1)

[Claims] 1. A target opening degree of an intake air amount control valve for adjusting an intake air amount of an internal combustion engine and a target rotation speed during idle operation are set, and a feedback control of the idle rotation speed of the internal combustion engine is allowed. It is determined whether or not it is in a specific operation state, and in the specific operation state, the target rotation speed is compared with the actual rotation speed, and the intake air amount control valve is controlled so that the actual rotation speed approaches the target rotation speed. The learning value data for reducing or canceling the difference between the opening degree and the target opening degree is calculated, and the opening degree of the intake air amount control valve is set based on the target opening degree and the learning value data except in the specific operation state. In an idle speed control method of performing open loop control on a control opening, a field current of a generator driven by the internal combustion engine is controlled when an electric load is applied to limit a sudden increase in power generation, and an operating state of the generator. Based on In addition to calculating the electric current value, the battery consumption current value is calculated based on the state of the battery, and the presence or absence of an electric load is determined based on the electric load current value calculated from the generated current value and the battery consumption current value. In the loop control, the intake amount control valve is set to a control opening that reflects the opening data for electric load compensation set based on the generated current value or the electric load current value when the occurrence of an electric load is determined. Control, the calculation of the learning value,
When it is determined that an electric load has been generated, the calculated value of the electric load compensating opening, which is set based on the generated current value, and learning value data for reducing or canceling the difference between the sum of the target opening and the actual opening. An idle speed control method characterized by: