JPH0451657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Regarding the idle speed feedback control method for an internal combustion engine of the present invention, in particular, the change in engine speed when the electrical load on the engine decreases during feedback control is suppressed, and the control accuracy is improved. This invention relates to an idle speed feedback control method.

Conventionally, a target idle speed is set, the difference between this target idle speed and the actual engine speed is detected, and the amount of air sucked into the engine is adjusted according to the size of the difference so that this difference becomes zero. An idle speed feedback control method is used in which the engine speed is controlled to maintain the target idle speed by adjusting the
No. 126634). In this method, when an electrical device such as a headlight is activated, a generator that supplies power to the electrical device is activated, and this operation becomes a load on the engine and reduces the engine speed, so the effect of increased load is to reduce the engine speed. The applicant has proposed an idle speed feedback control method that increases or decreases the amount of air taken into the engine by a predetermined amount in response to the on/off state of an electrical device. −066928).

However, when the required power of the electrical device exceeds the power generating capacity of the generator, the insufficient power is supplemented from the battery, so there may be cases where the off state of the electrical device and the load state of the engine do not correspond. That is, for example, when power is supplied from the battery to an electrical device and the battery becomes depleted such that the battery voltage V _B is lower than the predetermined voltage V _BEG ,
Since the generator maintains full power generation and charges the battery even after the electrical equipment is turned off, the engine is still subject to a load due to the operation of the generator even when the electrical equipment is turned off. Therefore, if the amount of intake air is reduced immediately when the electrical device is turned off, the engine will not be supplied with the amount of air commensurate with the load, resulting in a sudden decrease in engine speed, and then feedback control As a result, the engine speed is gradually returned to the predetermined speed. This sudden decrease in engine speed not only gives discomfort to the driver, but also delays charging of the battery, and there is a risk of engine stalling if the clutch is engaged when the engine speed suddenly decreases.

The present invention has been made in view of the above-mentioned points, and avoids a sudden drop in engine speed when the electrical device is turned off by supplying the engine with an amount of air corresponding to the load actually applied to the engine. The purpose is to In order to achieve this object, the present invention adjusts the operating amount of a control valve that adjusts the intake air amount of an internal combustion engine that is equipped with a plurality of electrical devices, a generator and a battery that supply electric power to these devices, to the actual operating amount during idling. In an idle speed feedback control method that performs control according to the difference between an engine speed and a target engine speed, the on-off state of each electrical device is detected, and the operating amount is adjusted based on the detected on-off state. A first correction amount to be corrected is determined and the actuation amount is corrected, and an amount of change in the first correction amount is determined when the at least one electrical device changes from on to off, and the amount of change in the first correction amount is determined when the at least one electrical device changes from on to off. determining a load parameter value of the electrical device in the on state before changing to the off state, comparing the load parameter value with a predetermined value, and changing the first correction amount when the load parameter value is larger than the predetermined value; The present invention provides a method for controlling the idle speed feedback of an internal combustion engine, in which the operating amount is corrected by a second correction amount depending on the magnitude of the amount.

An embodiment of the method of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram schematically showing the entire engine speed control device for an internal combustion engine to which the method of the present invention is applied. An intake passage (hereinafter referred to as "intake pipe") 3 to which an air cleaner 2 is attached is connected to an exhaust pipe 4. A throttle valve 5 is disposed in the middle of the intake pipe 3, and an air passage 8 that opens into the intake pipe 3 downstream of the throttle valve 5 and communicates with the atmosphere is disposed. An air cleaner 7 is attached to the open end of the air passage 8 on the atmosphere side.
Further, an auxiliary air amount control valve (hereinafter simply referred to as "control valve") 6 is arranged in the middle of the air passage 8.
This control valve 6 is a normally closed solenoid valve, and is composed of a solenoid 6a and a valve 6b that opens an air passage 8 when the solenoid 6a is energized.The solenoid 6a is an electronic control unit (hereinafter referred to as "ECU") 9. electrically connected to.

A fuel injection valve 10 is provided between the engine 1 of the intake pipe 3 and the opening 8a of the air passage 8, and this fuel injection valve 10 is connected to a fuel pump (not shown) and electrically connected to the ECU 9. It is connected.

A throttle valve opening sensor 11 is attached to the throttle valve 5, and a throttle valve opening sensor 11 is connected to the opening 8a of the air passage 8 of the intake pipe 3.
An intake pipe absolute pressure sensor 13 that communicates with the intake pipe 3 via a pipe 12 is installed on the downstream side, and an engine coolant temperature sensor 14 and an engine rotation angle position sensor 15 are installed on the engine 1 body, and each sensor is connected to the ECU 9. electrically connected.

Reference numerals 16, 17 and 18 indicate first, second and third electrical devices such as headlights, brake lights, radiator fans, etc., and the first, second and third electrical devices 16, 17 and 18 are switches 16a, 18, respectively. 17a, 18a, and connection point 19a, and is connected directly to the battery 19.
Each is connected to ECU9. An alternator 20 is connected to the connection point 19a, and a battery output voltage detector 21 is also connected to the voltage detector 2.
1 is connected to ECU9 and detected battery 19
The output voltage value signal is supplied to the ECU 9. Further, a regulator 20a is connected in parallel to the generator 20, and the field current of the generator 20 is controlled according to the output voltage value of the battery 19.

The generator 20 is the output shaft of the engine 1 (not shown)
It is mechanically connected to the engine 1 and is driven by the engine 1. And each switch 16a, 17a, 18a
is in the closed (on) state, and each electrical device 16,1
Electric power is supplied from the generator 20 to 7 and 18. When the total amount of electric power required for each electric device 16, 17, 18 to operate exceeds the power generation capacity of the generator 20, the regulator 20a is activated to increase the field current to the maximum rated current and to fully power the generator 20. Set to power generation state. Even so, the power that is still insufficient is compensated for by the battery 19, and the battery 19 is consumed and the output voltage value V _B of the battery 19 decreases from the predetermined value V _BEG . Therefore, when the battery 19 is exhausted, even if some or all of the switches 16a, 17a, and 18a are opened (off), the load of the generator 20, which is in full power generation state, is applied to the engine 1. It will continue to take place.

Throttle valve opening sensor 11, absolute pressure sensor 1
3. Engine operating state parameter signals from the cooling water temperature sensor 14 and engine rotation angle position sensor 15 and a battery output voltage signal from the voltage detector 21 are supplied to the ECU 9, and the ECU 9 receives the values of these engine operating state parameter signals and the engine operating state parameter signals. 1. 2nd
The engine operating state and the engine load state are determined based on the electrical load state signals from the third electric devices 16, 17, and 18 and the signal from the voltage detector 21, and the fuel supply to the engine 1 is determined based on these determined states. The supply amount, that is, the valve opening time of the fuel injection valve 10, and the auxiliary air amount, that is, the operating amount of the control valve 6, and in this embodiment, the valve opening time of the control valve 6 are calculated respectively, and fuel injection is performed according to each calculated value. A driving pulse signal is supplied to actuate the valve 10 and the control valve 6, respectively.

The solenoid 6a of the control valve 6 is energized for a valve opening time corresponding to the calculated value, and the valve 6b is opened to open the air passage 8, and a predetermined amount of air according to the valve opening time is supplied to the air passage 8 and the air passage 8. It is supplied to the engine 1 via the intake pipe 3.

The fuel injection valve 10 is opened for a valve opening time according to the above-mentioned calculated value to inject fuel into the intake pipe 3, and the injected fuel is mixed with the intake air and always maintains a predetermined air-fuel ratio (for example, stoichiometric air-fuel ratio). The air-fuel mixture is supplied to the engine 1.

When the amount of auxiliary air is increased by lengthening the opening time of the control valve 6, the amount of air-fuel mixture supplied to the engine 1 increases, the engine output increases, and the engine speed increases. Conversely, if the opening time of the control valve 6 is shortened, the amount of air-fuel mixture to be supplied will decrease and the engine speed will decrease. By controlling the amount of auxiliary air, that is, the opening time of the control valve 6 in this way, the engine speed can be controlled.

Figure 2 is a diagram showing the circuit configuration inside the ECU 9 in Figure 1, and shows the engine rotation angle position sensor 1 in Figure 1.
The output signal from 5 is waveform-shaped by a waveform shaping circuit 901, and then supplied to a central processing unit (hereinafter referred to as "CPU") 902 as a TDC signal.
It is also supplied to the Me counter 903. The Me counter 903 counts the time interval from the input of the previous TDC signal from the engine rotation angle position sensor 15 to the input of the current TDC signal, and its count value
Me is proportional to the reciprocal of the engine speed Ne. Me
Counter 903 supplies this count value Me to CPU 902 via data bus 904.

Detection signals from various sensors such as the throttle valve opening sensor 11, intake pipe absolute pressure sensor 13, water temperature sensor 14, etc. and the detection signal from the battery voltage detector 21 shown in FIG. 1 are adjusted to a predetermined voltage level by a level correction circuit 905. After being modified, multiplexer 90
6 is sequentially supplied to the A/D converter 907. The A/D converter 907 is connected to each sensor 1 described above.
The detection signals from 1, 13, 14 and the detector 21 are sequentially converted into digital signals, and the digital signals are supplied to the CPU 902 via the data bus 904.

First, second and third electrical devices 1 shown in FIG.
Switches 16a and 17 of 6, 17, and 18, respectively.
The on-off signal from a, 18a is corrected to a predetermined voltage level by a level correction circuit 908, converted into a predetermined signal by a data input circuit 909, and supplied to the CPU 902 via a data bus 904.

The CPU 902 further connects to a read-on memory (hereinafter referred to as "ROM") 9 via a data bus 904.
10. Random access memory (RAM) 911
and connected to drive circuits 912 and 913,
The RAM 911 temporarily stores calculation results etc. by the CPU 902, and the ROM 910 stores control programs etc. executed by the CPU 902.

According to the control program stored in the ROM 910, the CPU 902 determines the engine operating state and engine load state according to the aforementioned various engine parameter signals and battery voltage value signal, and opens the control valve 6 that controls the amount of auxiliary air. Duty ratio
Dout is calculated and a control signal corresponding to this calculated value is supplied to the drive circuit 912.

The calculation of this valve opening duty ratio Dout is given by the following equation (1) as described later.

Dout = D _PIo + D _Eo ...(1) Here, D _E is the value set corresponding to the magnitude of the load of each electrical device (hereinafter referred to as electrical load term) to correct the operating amount of the control valve 6. Corresponds to a correction amount of 1. D _PIo is a feedback term, and this feedback term D _PIo is further given by the following equation (2).

D _PIo = D _PIo + D _ETo (2) Here, the feedback term D _PIo is set for each TDC signal depending on the magnitude of the difference between the target idle speed and the actual engine speed. D _ETo is a value that is set according to the load condition of the generator applied to the engine as described later when the electrical device is turned from on to off, and corresponds to the second correction amount that corrects the operating amount of the control valve 6. do.

The CPU 902 further calculates the fuel injection time T _OUT of the fuel injection valve 10 and sends a control signal based on this calculated value to the drive circuit 913 via the data bus 904.
supply to. The drive circuit 913 supplies the fuel injection valve 10 with a control signal that opens the fuel injection valve 10 according to the calculated value, and the drive circuit 912 supplies an on-off drive signal that turns the control valve 6 on and off to the control valve 6. supply to.

Figure 3 is a flowchart of a calculation program that calculates the electrical load term D _Eo and the index number η _INDo that represents the load parameter value of the electrical load for the engine.
Executed every TDC signal.

When this calculation program is called (step 1 in FIG. 3), first, the stored values of D _Eo and η _INDo are reset to zero (step 2). Next, it is determined whether the switch 16a of the first electrical device 16 shown in FIG. 1 is in the on state (step 3), and if the determination is negative (NO), the process proceeds to step 5.
If the determination result is positive (YES) in step 3,
A predetermined amount D _E1 corresponding to the electrical load of the first electrical device 16 is added to the stored value of D _Eo , and this added value (D _Eo +
D _E1 ) is set as a new stored value of D _Eo , and a value corresponding to the load of the first electrical device 16 is added to the stored value of η _INDo , and this added value is set as a new stored value of η _INDo (step 4). ). The value corresponding to the load of the first electrical device 16 may be a numerical value representing the power consumption of the device 16, or may be a predetermined value set according to the power consumption of the electrical device. In this embodiment, a case will be described in which the index number η _INDo is set to 4, 2, and 1 for the first, second, and third electrical devices 16, 17, and 18, respectively. In this case, in step 4, 4 is added to the stored value of η _INDo .

Next, the on/off state of the switch 17a of the second electric device 17 is determined in the same manner as described above (step 5). If it is not on, the process proceeds to step 7, and if it is on, the stored value of D _Eo is set. 2 electrical equipment 17
A predetermined amount D _E2 corresponding to the electrical load of is added, and this added value (D _Eo +D _E2 ) is used as a new memory value of D _E , and the index number set corresponding to the second electrical device 17 is added. 2 to the stored value of η _INDo ,
This added value (η _INDo +2) is set as a new stored value of η _INDo (step 6). Furthermore, as above, the third
The on/off state of the switch 18a of the electrical device 18 is determined (step 7), and if it is not on, the process proceeds to step 9, which will be described later.
A predetermined amount D _E3 corresponding to the electrical load of the third electrical device 18 is added to the stored value of D _Eo , and this added value (D _Eo +
D _E3 ) as the new memory value of D _Eo , and the third
The index 1 set for the electrical device 18 is added to the stored value of η _INDo , and this added value (η _INDo +1) is set as the new stored value of η _INDo (step 8).

Next, the process proceeds to step 9, where it is determined whether the stored value of D _Eo is larger than a predetermined maximum value D _EMAX , and if the determination result is negative (NO), the execution of the current loop of the program is terminated, Apply the memorized value of D _Eo as the electrical load term. If the determination result in step 9 is affirmative (YES), that is, the stored value of D _Eo is the maximum value.
If it is larger than D _EMAX , proceed to step 10, set the maximum value D _EMAX as the new memory value of D _Eo , end the execution of the current loop of the program, and set the maximum value D _EMAX
is applied as the electrical load term. This value D _EMAX is a value corresponding to the maximum load of the generator 20 applied to the engine, and if the field current of the generator 20 is the maximum rated current value, no more load will be applied to the engine. It is preset to a value commensurate with this load.

Figure 4a shows the value corresponding to the second correction amount mentioned above.
This calculation program calculates D _ETo , and this calculation program is executed in the ECU 9 for each TDC signal.

When this calculation program is called (step 11), it first calculates the electric load term D _Eo calculated by the program shown in Figure 3 at the current TDC signal and the previous TDC.
Difference from the electrical load term D _Eo-1 obtained at the time of signal ΔD _Eo =
D _Eo -D _Eo-1 is obtained and it is determined whether this difference ΔD _Eo is greater than or equal to 0 (step 12). If this determination result is affirmative (YES), that is, if the current electrical load is the same as the previous time or has increased from the previous time,
Since there is no need to correct the valve opening duty ratio D _OUT using the D _ETo value, D _ETo is set to 0 (step 13), and the execution of the current loop of the program is ended.

If the determination result in step 12 is negative (NO),
That is, if the current electrical load has decreased from the previous time, the process proceeds to step 14, and the average value V BX of the output voltage V _B of the battery 19, which is a parameter value representing the power generation state _{of the generator 20, is lower than the predetermined value V BEG .} It is determined whether it is low or not. This average value V _BX is, for example, the fourth
It is calculated every time the TDC signal is generated in the V _BX calculation subroutine shown in FIG. b. That is, the output voltage of the battery 19
V _B is detected by the voltage detector 21 (step 21), and then, in step 22, the average value V _BX of the battery voltage is calculated based on the detected value V _B. This calculation is performed, for example, using the following equation.

V _BXo = X/256V _Bo +256-X/256V _BXo-1 ...( ₂ ) Here,
is the average value found last time, and V _Bo is the current detected value of battery voltage.

The reason why the average value V _BX of the voltage detection value V _B is used as the value to be compared with the predetermined value V _BEG in step 14 is because the charging pressure of the battery by the alternator 20 is pulsating and the battery voltage value is not accurate due to noise etc. V _B
This is because the noise cannot be detected, and the X value in the above equation (2) is set based on the magnitude of the influence of these noises. Further, the predetermined value V _BEG is a preset value that is used as a criterion for determining whether or not the operation of the generator 20 applies a high load to the engine, as described above.

Returning to FIG. 4a, if the determination result in step 14 is affirmative (YES), that is, even though the battery 19 is exhausted and the electrical load has been reduced, the generator 20 is in a full power generation state as described above. If a load is applied to the engine, proceed to step 15 and set the D _ETo value to the value obtained by multiplying the difference ΔD _Eo obtained in step 12 by (-1) for the reason described later. Terminate execution.

If the determination result in step 14 is negative (NO),
That is, if it is determined that the battery voltage is higher than the predetermined value V _BEG , the program proceeds to step 16, and the engine load condition is determined based on the previous value η _INDo-1 of the index number η _IND calculated using the program shown in FIG. Discern. The reason why the engine load state is further determined using the index number η _INDo when it is determined that the battery voltage value is higher than the predetermined value V _BEG is as follows. Whether or not the generator 20 is in a full power generation state can be accurately determined by detecting the output current of the generator or the magnitude of the field current that correlates with the output current. In order to accurately detect the magnitude of the field current, an expensive device must be used, and such a device is large, making it inconvenient to mount it on a vehicle.

On the other hand, battery voltage can generally be detected relatively easily with a small and inexpensive detector, so instead of detecting the field current described above, the battery voltage can be detected using the voltage detector 21.
If the state of the generator 20 is determined by detection, it will be advantageous in terms of cost and mounting on the vehicle. However, as the battery voltage V _B progresses in charging the battery 19 and approaches the predetermined value V _BEG , the change in the output voltage becomes smaller, making it difficult to accurately detect the output voltage value V _B. Further, if the characteristics of the voltage detector 21 change due to, for example, temperature, it becomes difficult to accurately detect the output voltage value _VB .
Furthermore, since the control voltage of the regulator similarly changes depending on the temperature, when setting the predetermined value V _BEG to be fixed, it must be set small in anticipation of temperature changes in the control voltage. Therefore, voltage detector 21
Even if it is determined that the generator 20 is not in a full power generation state based on the detection result (the determination in step 14 is negative),
In reality, the battery voltage V _B is low and the generator 20 is in a full power generation state, or even if the battery voltage V _B is actually determined to be higher than the predetermined value V _BEG , the full power generation state may continue. . Therefore, in step 16, it is detected when any one electrical device is turned off, and the generator 20 is turned off before the detection.
The index number η _INDo-1 at the previous loop is 5, for example.
The determination is made based on whether or not it is larger. If this determination result is affirmative (YES), that is, step 14
Even if it is determined that the battery 19 is not exhausted, if the generator 20 was in full power generation state until the previous loop, the load of the generator 20 in full power generation state will continue to be applied to the engine during the current loop. In this case, proceed to step 17 and set the D _ETo value to the previous step for reasons explained below.
The difference ΔD _Eo obtained in step 12 is multiplied by (-1) and then set to a value that is further multiplied by a predetermined coefficient value _XET , and the execution of the current loop of the program is ended. This predetermined coefficient value X _EX takes a value of 0≦X _ET ≦1, and for example,
X _ET = 0.6.

If the determination result in step 16 is negative (NO),
That is, if it is determined that the battery voltage has recovered during the current loop, and furthermore, it is determined that the generator 20 was not in the full power generation state during the previous loop, the load of the generator 20, which is in the full power generation state, will not be applied to the engine during the current loop. Since it can be determined that there is no such program, D _ETo is set to 0 (step 18), and the execution of the current loop of the program is ended.

Figure 5 shows the electric load terms D _Eo and D _ETo values mentioned above and the feedback term D _PIo calculated as described below.
This calculation program calculates the valve opening duty ratio D _OUT by
Executed every TDC signal.

When this program is called (step 31 in Figure 5), first, a number Me proportional to the reciprocal of the actual engine speed Ne is set to the upper limit of the target idle speed N _H
It is determined whether or not it is smaller than the number M _H corresponding to the reciprocal of (step 32). This determination result is negative (NO)
In this case (that is, Ne≦ _NH ), the process proceeds to step 33, where it is determined whether the number Me is larger than the number M _L corresponding to the reciprocal of the lower limit value N _L of the target idle speed. When the determination result in step 33 is negative (NO), that is, it is determined that the engine speed Ne is between the upper and lower limits of the target idle speed N _H and N _L based on the determination results in steps 32 and 33. Since there is no need to increase or decrease the actual engine speed Ne, the deviation value ΔMn is set to zero (step 34), and the value of the feedback term D _PIo is set to the value of the previous loop D _PIo-1 (step 34). 35), proceed to step 36.

The above-mentioned values M _H and M _L are determined so that the exhaust gas characteristics and fuel efficiency characteristics are optimized depending on, for example, the water temperature signal from the cooling water temperature sensor 14 and the engine load of the electrical devices 16 to 18. Set.

When the determination result in step 33 is affirmative {YES},
This means that the actual engine speed Ne is determined to be smaller than the lower limit value N _L , and in step 37, the deviation value ΔMn
(At this time, ΔMn becomes a positive value) is determined, and this deviation value ΔMn is multiplied by a constant number _K1 to determine the integral control term _ΔD1 (step 38). Next step
The difference between the deviation value ΔMn obtained in step 37 and the deviation value ΔM _o-1 in the previous loop, that is, the acceleration deviation value ΔΔMn
is obtained (step 39), and the proportional control term ΔDp is obtained by multiplying this acceleration deviation value ΔΔMn by a constant number Kp (step 40). The value obtained by adding the control value D _PIo-1 of the previous loop to the integral control term ΔD ₁ and proportional control term ΔDp obtained in this way is set as the current feedback term D _PIo (step
41), then proceed to step 36.

If the determination result in step 32 is affirmative (YES), it is determined that the actual engine speed Ne is greater than the upper limit value N _H of the target idle speed,
In step 42, the deviation value ΔMn (in this case, ΔMn becomes a negative value) is determined, and in the same way, in step 38, the integral control term ΔD ₁ is determined, in step 40, the proportional control term ΔDp, and in step 41, the current feedback term is determined.
D _PIo will be requested and you will proceed to step 36.

Next, add D _ETo to the D _PIo value obtained in step 35 or 41.
Add the values and use it as the new D _PIo value (step
36), and the value obtained by adding the electrical load term D _Eo to this D _PIo value is set as the valve opening duty ratio Dout (step
43), ends the execution of the current loop of the program. As a result, when D _ETo = 0 (steps 13 and 18 in Figure 4a), the Dout value is the sum of the D _PIo value calculated in step 35 or 41 and the electrical load term D _Eo during the current loop. is the sum of Also, D _ETo =−
When ΔD _Eo (=-D _Eo +D _Eo-1 ) is set (Step 15 in Figure 4a, Dout=D _PIo +D _Eo-1 , which is maintained at the value before the electrical load reduction, and the electrical equipment is Generator 20 in full power generation state even after being turned off
An amount of air commensurate with the load, in this embodiment an auxiliary air amount, is supplied to the engine. D _ETo =X _ET (−ΔD _Eo )
(Step 17 in Figure 4a)
is Dout = D _PIo + D _Eo + X _ET・(D _Eo-1 − D _Eo ), and as mentioned above, if X _ET = 0.6, the valve opening duty ratio Dout is the feedback term during the current loop.
The sum of D _PIo and electrical load term D _Eo plus the difference in electrical load term (−ΔD _Eo ) between the previous loop and this loop is 6.
The value is the sum of the percentages. Therefore, as mentioned above, if there is a possibility that the load of the generator 20 in full power generation state continues to be applied to the engine during this loop, the difference (-ΔD _Eo ) of this electrical load term is 6.
Since the control valve 6 is controlled by the valve opening duty ratio Dout with the added value, the risk of the engine speed decreasing significantly is avoided. Also, since the D _PIo value set in step 36 is used as the D _PIo-1 value in the next loop (step 35 or 41), the Dout value from next time onwards will be changed from the Dout value in this time to step 38.
It changes gradually according to the integral term ΔD ₁ and the proportional term ΔDp of 40 and 40, and a sudden change in the engine speed Ne can be avoided.

In the above embodiment, the auxiliary air control valve 6 disposed in the air passage 8 is controlled to adjust the intake air amount of the engine, but the present invention is not limited to this, and the intake air amount of the engine is adjusted. For example, the throttle valve opening may be directly controlled. Further, instead of controlling the actuation amount of the control valve as the duty ratio of the valve opening time of the control valve as in the above embodiment, the valve opening degree may be controlled.

As explained above, according to the present invention, the operation amount of the control valve that adjusts the intake air amount of the internal combustion engine, which is equipped with a plurality of electrical devices, a generator and a battery that supply electric power to these devices, is adjusted during idling. In an idle speed feedback control method that controls according to the difference between an actual engine speed and a target engine speed, the on-off state of each of the electrical devices is detected, and the operating amount is determined based on the detected on-off state. A first correction amount is determined to correct the operation amount, and when the at least one electrical device changes from on to off, an amount of change in the first correction amount is determined, and when the at least one electrical device changes from on to off, - determining the load parameter value of the electrical device in the on state before changing to the off state and comparing the load parameter value with a predetermined value, and when the load parameter value is larger than the predetermined value, the first correction amount is Since the actuation amount is corrected by the second correction amount depending on the magnitude of the change, the amount of air corresponding to the load actually applied to the engine is supplied to the engine when the electrical device is turned off. This makes it possible to avoid a sudden drop in engine speed when the electrical equipment is turned off.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram of an internal combustion engine control device to which the control method of the present invention is applied, Figure 2 is an electrical circuit diagram inside the electronic control unit (ECU) shown in Figure 1, and Figure 3 is an electrical load term D. A flowchart showing a calculation program for _Eo and the index number η _INDo , Fig. 4a is a flowchart showing a calculation program for the second correction value D _ETo , and Fig. 4b is a flowchart of a subroutine for calculating the average value of battery voltage. The chart shown in FIG. 5 is a calculation program for the feedback term _DPIo and the valve opening duty ratio Dout. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 3... Intake passage, 5... Throttle valve (throttle valve), 6... Auxiliary air control valve, 8... Air passage, 9... Electronic control unit, 10...
Fuel injection valve, 16, 17, 18... Electric device, 19
... Battery, 20... Generator, 21... Battery output voltage detector, V _B ... Battery output voltage value, V _BX ... Average value, V _BEG ... Predetermined value, D _PIo ... Feedback term,
D _Eo ...Electrical load term, Dout...Valve opening duty ratio,
η _INDo …Number of indexes.

Claims (1)

[Claims] 1. The operating amount of a control valve that adjusts the intake air amount of an internal combustion engine that is equipped with a plurality of electrical devices, a generator and a battery that supply electric power to these devices, is determined based on the actual engine rotational speed during idling. In the idle rotation speed feedback control method, the idle rotation speed feedback control method performs control according to the difference between the engine rotation speed and the target engine rotation speed. 1 and corrects the operation amount, and when the at least one electrical device changes from on to off, the first
The amount of change in the correction amount of the electric device is determined, and
determining a load parameter value of the electrical device in the on state before changing to the off state, comparing the load parameter value with a predetermined value, and changing the first correction amount when the load parameter value is larger than the predetermined value; A method for controlling an idle rotation speed of an internal combustion engine, characterized in that the operating amount is corrected by a second correction amount depending on the magnitude of the amount. 2. The idle speed feedback control method for an internal combustion engine according to claim 1, wherein the load parameter value of the electrical device is determined by the sum of power consumption for each electrical device in an on state. 3. Idle speed feedback control for an internal combustion engine according to claim 1, wherein the load parameter value of the electrical device is determined by the sum of predetermined values set corresponding to each electrical device in an on state. Method. 4. The internal combustion engine according to any one of claims 1 to 3, wherein the amount of change in the first correction amount is multiplied by a predetermined coefficient value to obtain the second correction amount. idle speed feedback control method. 5. Detecting a parameter value representing the amount of power output by the generator when the at least one electrical device changes from on to off, and comparing the detected value with a first predetermined value, 2. The idle speed feedback control method for an internal combustion engine according to claim 1, wherein the operating amount is corrected by the second correction amount when it is smaller than a first predetermined value. 6. Claims characterized in that the detected value of the parameter representing the amount of power output by the generator is the output voltage value of the battery, and when the battery voltage becomes large, it is determined that the output of the generator is small. 6. The idle speed feedback control method for an internal combustion engine according to claim 5.