JP3044408B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device for controlling an engine torque particularly at the time of idling.

[0002]

2. Description of the Related Art In an engine for a vehicle or the like, in order to stabilize the engine speed during idling, a target engine speed during idling is set according to the water temperature and the state of an external load. Normally, idle control is performed so that the idle speed converges to the target speed by correcting the filling amount with bypass air or the like based on rotational feedback based on the deviation from the above. However, in the idle control based on the rotation feedback, rotation fluctuation when an external load applied to the engine changes due to operation / stop of a compressor or a power steering pump of an air conditioner cannot be sufficiently suppressed.
In view of this, the present applicant previously disclosed in Japanese Patent Application No. 1-338511, a target filling amount was set according to a target rotation speed during idling, and a filling amount was set according to a deviation between the target filling amount and the actual filling amount. It proposes performing idle control by correction. When the idle control is performed by the feedback of the filling amount in this way, the torque control is particularly well performed at the transient time when the external load changes as described above, and thereby the rotation fluctuation is more effectively suppressed.

[0003]

Incidentally, even when the idle control is performed by the filling amount correction according to the difference between the target filling amount and the actual filling amount as described above, the filling amount is corrected by the bypass air or the like. In this case, since the response delay is large, it is not sufficient to suppress the rotation fluctuation at the transient time when the external load or the like suddenly changes. Therefore, it is considered effective to perform a highly responsive torque correction by correcting the ignition timing or the like based on the deviation between the target filling amount and the actual filling amount in the transient state. However, if the torque correction is performed based on the ignition timing or the like by the feedback of the charging amount during the transition, a new problem occurs because the feedback is the charging amount. In other words, the flow characteristics of the flow control valve that adjusts the flow rate of the bypass air have manufacturing variations, and there are variations due to aging or clogging. Even when the target filling amount and the actual filling amount have some deviation, and moreover,
The deviation is not constant. The steady-state deviation not caused by the load change is detected as being included in the deviation between the target filling amount and the actual filling amount even during a transient time when the load changes suddenly. Therefore, the correction of the ignition timing or the like performed based on the deviation between the target filling amount and the actual filling amount during the transition may not be in accordance with the actual excess / deficiency torque during the transition, and in some cases, A situation in which the rotation fluctuation increases on the contrary also occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to correct a torque in accordance with a deviation between a target filling amount and an actual filling amount, and to provide a flow control valve for adjusting a bypass air amount. It is an object of the present invention to prevent a rotation fluctuation during a transient when an external load of an engine caused by an air conditioner or the like suddenly changes without being affected by a variation in a flow rate characteristic.

[0005]

The structure of the present invention is as shown in FIG. That is, the engine control device according to the present invention includes: a torque parameter detection unit that detects a parameter related to engine torque; a torque parameter target value setting unit that sets a target value of the parameter according to a load state of the engine; Load change determining means for determining a change in the load state from the change in the target value, receiving an output of the load change determining means, and calculating a deviation between a target value and an actual value of the parameter in a steady state where the change in the load state is small. Receiving the outputs of the steady-state deviation detecting means for detecting and the load change determining means,
A transient deviation detecting means for detecting a deviation between a target value and an actual value of the parameter when a change in the load state is equal to or more than a predetermined value; and a transient deviation detecting means for detecting a deviation between the target value and the actual value of the parameter when the change in the load state is equal to or more than a predetermined value. Correction amount setting means for setting a correction amount for torque control based on a value obtained by subtracting a deviation between a target value and an actual value of the parameter at steady state from the deviation, and an engine torque corresponding to an output of the correction amount setting means. And torque control means for controlling the torque.

Further, the present invention may be an engine control device for controlling the actual charge amount so that the charge amount of the engine at the time of idling converges to the target charge amount. Sometimes, a correction amount of the filling control is set based on a value obtained by subtracting a deviation between the target filling amount and the actual filling amount in a steady state from a deviation between the target filling amount and the actual filling amount, and the engine is controlled according to the correction amount. The filling amount can be controlled.

The present invention also relates to an engine control device for controlling the actual charge amount so that the charge amount of the engine at the time of idling converges to the target charge amount. A correction amount for the filling control is set based on a value obtained by subtracting a deviation between the target filling amount and the actual filling amount in a steady state from a deviation between the filling amount and the actual filling amount, and the ignition timing of the engine is set in accordance with the correction amount. Is controlled. Also, at this time, in order to prevent the rotation from rising or falling during the unstable period following the start of the external load operation, the ignition timing correction when the load condition is equal to or more than the predetermined value even after the change in the load condition does not exceed the predetermined value. May be provided for extending the correction continuation period for a predetermined period.

[0008]

According to the present invention, an engine control device according to the present invention controls the operation of an air conditioner or the like according to an external load applied to the engine.
For example, a target value such as a filling amount at the time of idling is set. Conversely, the change in the load state is determined by observing the change in the target value, and the following torque correction is performed when the change in the load state is equal to or more than a predetermined value. That is, the actual value such as the filling amount, which is a parameter related to the engine torque, is detected, and at the time of a large load change, a deviation between the target value and the actual value of the filling amount is detected. A value obtained by subtracting the deviation between the target value and the actual value in the steady state where the change is small is obtained, and based on the value, torque control such as ignition timing control, charge control using an electrically controlled throttle valve, or fuel control is performed. Set the correction amount. Then, the engine torque is corrected based on the correction amount, and for example, the excess / deficiency torque at the time of transition when the actual charging amount is controlled so that the charging amount at idling converges to the target charging amount is corrected.

[0009] The deviation between the target filling amount and the actual filling amount detected during the transition includes a deviation in a steady state caused by a variation in the flow control valve for the bypass air. Therefore, the value obtained by subtracting the steady-state deviation from the detected deviation corresponds to the excess / deficiency torque during the transition, and by performing the torque correction based thereon, the influence such as the variation of the flow control valve is eliminated. Thus, the occurrence of rotation fluctuation due to the variation is prevented.

Further, in performing the torque correction based on the ignition timing, even if the change in the load state does not exceed a predetermined value,
Without immediately stopping the correction, the correction can be continued for a predetermined period of time, thereby preventing the rotation from rising or falling in the unstable period after the end of the transient determination.

[0011]

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

FIG. 2 is an overall system diagram of the first embodiment of the present invention. In this embodiment, an engine 1 includes a cylinder 2 and a cylinder head 3 that covers an upper portion of the cylinder 2.
And a piston 4 reciprocating in the cylinder 2. In the cylinder 2, a combustion chamber 5 is defined between the cylinder head 3 and the piston 4, and an ignition plug 6 is mounted on the cylinder head 3 so as to face the combustion chamber 5. An intake port 7 and an exhaust port 8 are formed on the left and right of the cylinder head 3 with the ignition plug 6 interposed therebetween.
And an exhaust valve 10 are provided. Further, an air flow meter 12 for detecting an intake air amount is provided upstream of the intake passage 11 of the engine 1, and a throttle valve 14 is provided upstream of a surge tank 13 downstream thereof.
An injector 15 for fuel injection is arranged at a cylinder head connection portion close to the intake port 7. A bypass passage 16 that bypasses the throttle valve 14 is formed, and an ISC (idle speed adjustment) valve 17 that is a duty solenoid type flow control valve is provided in the middle of the bypass passage 16. Further, a catalyst device 19 is provided in the exhaust passage 18 of the engine 1.
The cylinder 2 is provided with a water temperature sensor 20 for detecting a temperature of the cooling water of the engine 1.

A control unit 21 for controlling the engine 1 receives an intake air amount signal from the air flow meter 12 and a water temperature signal from the water temperature sensor 20, and receives a signal from a crank angle sensor attached to a distributor 22. A crank angle signal and an idle switch signal from an idle switch attached to the throttle valve 14 are input. Control unit 2
1, an external load signal indicating operation / stop of an air conditioner or the like is input. The control unit 21 outputs an ignition signal to the igniter 23 based on these signals, an injection signal to the injector 15, and an IS signal to the ISC valve 17.
It outputs a C valve drive signal.

The control of fuel injection during normal operation of the engine 1 is known, and a value obtained by dividing the amount of intake air by the engine speed obtained from the crank angle signal (intake charge amount) is multiplied by a constant. The final injection amount is determined by adding various correction amounts such as water temperature correction and acceleration correction to the basic injection amount, and further adding a voltage correction for compensating the invalid injection time. Then, the injector 15 is driven by an injection pulse having a pulse width corresponding to the final injection amount.

Regarding the ignition timing, normally, an advance angle control based on the engine speed is performed as is well known.

Next, the idle control of this embodiment will be described with reference to the time chart of FIG.

FIG. 3A shows an ON / OFF signal of an external load when the air conditioner is started or stopped. (B) shows the filling amount (a value obtained by dividing the intake air amount by the engine speed). Target filling amount at idling (Ce
TN) is set to a value corresponding to the idling target rotational speed when the external load signal is OFF as shown by the dotted line in FIG. 2B, and when the external load signal is ON, the filling amount corresponding to the load is set. Only a rectangular wave. The control of the idling speed is basically based on the target filling amount (Cetn).
This is performed by driving the ISC valve 17 with a duty ratio according to e).

Here, IS based on the volume of the intake system, etc.
In order to properly determine the excess or deficiency of the charged amount caused by the load change in consideration of the first-order lag of C, a value obtained by using the coefficient determined by the specifications of the intake system for the above Cetne is obtained. The average value (Cetned) of this Cetne is shown by a chain line in the figure. Cetned gradually rises when the load rises while the Cetne rises in a rectangular wave shape, and gradually decays when the load turns off while the Cetne also falls in a rectangular wave shape.

The actual filling amount (Ce) is shown in FIG.
As shown by the solid line. The actual filling amount (Ce)
Is a value obtained by taking into account the volume of the intake system and the like, and using the same coefficient as above to calculate the filling amount obtained from the raw detection value of the air flow meter 12.

FIG. 3C shows a deviation (ΔCetne) between the above Cetne and Cetned used to determine a change in the load state. Depending on whether or not the value of ΔCetne (dceabs (= Cetne−Cetned)) exceeds the determination line on the plus side and the minus side, it is determined that the load state is steady if not, and if it exceeds, it is determined that the load is in a transient state. Then, when it is determined that the time is a transition, a flag is set as shown in (d) and a counter (Cdce) is set as shown in (e).
Is set, and the value of the deviation (ΔCetne) (d
When (ceabs) returns within the determination line, the flag is lowered and the counter (Cdce) is decremented. And (f)
As shown in (1), a transient flag (Xdce) for performing a transient correction is set from when the counter (Cdce) is set to when it becomes zero or less.

FIG. 3 (g) shows the steady state deviation (-ΔCe) of the filling amount as data for performing torque control by ignition timing correction during transition without being affected by variations in the ISC valve 17 and the like. ing. Here, the value of ΔCe (dc
etno) is dcetno = Ce-Cetne, which is held at the value immediately before the transition.

FIG. 3 (h) shows the filling amount as in (b) above, and the solid line shows the target filling amount (Cetn).
e) minus the steady-state deviation (−ΔCe) (Cet
ne + ΔCe), and the dotted line is the same actual filling amount (Ce) as the solid line in (b) above. In a steady state, the value of ΔCe (dcetno) is Ce−Cetne, so the value of the solid line (Cetne + ΔCe) is Cetne + (Cene).
-Cetne), which is equal to the actual filling amount (Ce). Further, during a transition, since the steady-state deviation immediately before being held is used as the value of ΔCe (dcetno), the value is deviated from the actual filling amount (Ce) as shown in FIG. Here, the value (Cetne +
The difference between ΔCe) and the actual filling amount (Ce) indicated by the dotted line is a value excluding the steady-state deviation (−ΔCe), and indicates a substantial excess / deficiency of the filling amount due to the load change.

FIG. 3 (i) shows the solid line value (C) of the above (h).
etne + ΔCe) and the difference (ΔC) between the actual filling amount (Ce)
eld). Here, the value of ΔCeld (dceld) is dcel = (Cetne + ΔC
e) -Ce, as shown in the figure, when the load is ON, it is approximately plus side (filling amount is insufficient), and when the load is OFF, it is on the minus side (filling amount is excessive), indicating the excess / defective filling amount at the time of transition. Therefore, the value of this ΔCeld (dceld)
The correction amount (thtdce) of the ignition timing based on the above is set, and the ignition timing is controlled by the correction amount (thtdce).

FIG. 3 (j) shows the above thtdce. When the value of ΔCeld (dceld) is positive (insufficient charge), the ignition timing is corrected to the advanced side,
When the value of Celd (dceld) is negative,
Correct the ignition timing to the retard side. This compensates for the excess and deficiency of the engine torque due to the excess and deficiency of the filling amount, and prevents the rotation fluctuation during the transition.

FIGS. 4 and 5 are flowcharts for executing the idle control. Hereinafter, this will be described. Note that S1 to S35 indicate each step.

When starting, the engine speed (Ne) is read in S1, and the intake air amount (Qa) is read in S2. Then, in S3, an apparent filling amount (Ce ₀ ) is calculated by multiplying Qa / Ne by K (constant).

Next, in S4, the actual filling amount (Ce) is calculated based on the above Ce ₀ using a predetermined averaging coefficient (α).

Next, at S5, the engine coolant temperature (thw) is read, and then at S6, the basic ignition timing (thtbs) as a function of the engine speed (Ne) and the actual charge (Ce).
e) is set, and the basic ISC flow rate is set as a function of the water temperature (thw) in S7.

Next, in S8, it is determined whether or not a load such as an air conditioner is turned on. Then, if the load is ON, the process goes to S9, and the filling amount (Ce
ac) is a preset data value (KICEAC)
If the load is not ON, Ceac is set to zero.

Next, at S11, the engine coolant temperature (thw)
Is set as the target rotation speed (N ₀ ) during idle. Then, in S12, the basic ISC flow rate (Cebs
The target filling amount (Cetne) is calculated by adding the filling amount (Ceac) corresponding to the load to e) and converting it to the level of the target rotation speed (N ₀ ). In S13,
Average value (Cetne) of the target filling amount (Cetne)
d) is calculated using the smoothing coefficient (α),
Next, the process proceeds to S14, and the value (dceabs) of the deviation (ΔCetne) for load change determination is obtained as the absolute value of the difference between Cetne and Cetned.

Next, at step S15, the value (dceabs) of the deviation (ΔCetne) of the load change determination is set to a predetermined value (K).
Determine if d) is exceeded. If it exceeds, it means that it is in a transitional state, so it goes to S16 to set a transient flag (Xdce), and in S17 it sets a counter (Cdce).
Is set to a predetermined value (KCDCE). Also, S15
If dceabs does not exceed Kd, it means that it is in a steady state, so go to S18, decrement the counter (Cdce), and see in S19 whether Cdce has become zero or less. , If it becomes zero or less, the flow goes to S20 to reset the transient flag (Xdce),
In step S21, the counter (Cdce) is fixed to zero.

Next, in S22, it is determined whether or not the vehicle is idling. If it is idle, it is checked in step S23 whether the transient flag (Xdce) is set. If the transient flag (Xdce) is set, in step S24, the value of ΔCeld indicating the excess / deficient filling amount during the transition is set. (Dceld) is calculated. Here, dceld is the target filling amount (Cet
ne), a value obtained by converting the steady-state deviation (dcetno) of the filling amount into the target rotation speed (N ₀ ) is added, and the actual filling amount (Ce) is subtracted from the calculated value. In addition, the transient flag (Xdc
If e) does not stand, the steady-state error dcet is determined in S25.
No is calculated as dcetno = (Ce-Cetne) × Ne /
The calculation is performed using the equation of N ₀ , and dceld is fixed to zero in S26.

Next, in S27, Kt is added to the dceld.
By multiplying by (constant), an ignition correction amount (retard amount) thtdce according to dceld is calculated. Also, S2
8, the rotational deviation (N ₀ -Ne) is multiplied by Kf (constant) is calculated ignition feedback correction amount (thtfb).
Then, in S29, the above-mentioned thtdce is subtracted from the basic ignition timing (thtbse), and further the thtfb is added to calculate a final ignition timing (thtig). Then, in S30, ignition is performed. Then, in step S31, the ISC duty is calculated as a function of the product of the target filling amount (Cetne and the engine speed (Ne). In step S32, the ISC duty is calculated based on the duty.
Drive.

If it is determined in step S22 that the vehicle is not idling, then in steps S33 to S35, dceld, thtdce, th
A value such as tfb is fixed to zero, and ignition and ISC are controlled in S29 to S32.

In the above-described embodiment, the torque control for correcting the excess or deficiency in the transient state is performed by correcting the ignition timing. However, the torque control is performed by, for example, an electrically controlled throttle valve. It is also possible to perform the correction by the filling amount or the fuel control.

[0036]

Since the present invention is configured as described above, the actual charge amount is controlled so that the charge amount of the engine at the time of idling converges to the target charge amount, and the transient load in which the external load changes. At times, rotation fluctuations caused by excess or deficiency of the filling amount are suppressed by torque correction according to the deviation between the target filling amount and the actual filling amount, and rotation fluctuations are suppressed due to variations in the flow characteristics of the ISC valve etc. Can be prevented from being lost.

When the torque correction is performed by the ignition timing control, the torque correction is continued for a predetermined period even after the load condition does not exceed a predetermined value, so that the rotation speeds up or down after the external load is activated. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of the present invention.

FIG. 2 is an overall system diagram of an embodiment of the present invention.

FIG. 3 is a time chart illustrating control of the embodiment.

FIG. 4 is a flowchart for executing the control of the embodiment.

FIG. 5 is a flowchart for executing the control of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 6 Spark plug 12 Air flow meter 17 ISC valve 21 Control unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI F02P 5/15 F02P 5/15 EK (58) Investigated field (Int.Cl. ⁷ , DB name) F02D 45/00 312 F02D 45/00 322 F02D 45/00 330 F02D 41/08 315 F02D 41/16 F02P 5/15

Claims (4)

(57) [Claims] A torque parameter detecting means for detecting a parameter related to an engine torque; a torque parameter target value setting means for setting a target value of the parameter according to a load state of an engine; Load change determining means for determining a change in load state, and steady-state deviation detecting means for receiving an output of the load change determining means and detecting a deviation between a target value and an actual value of the parameter in a steady state where the load state change is small. A transient deviation detecting unit that receives an output of the load change determining unit and detects a deviation between a target value and an actual value of the parameter when the change in the load state is equal to or more than a predetermined value; At that time,
Correction amount setting means for setting a correction amount for torque control based on a value obtained by subtracting a deviation between a target value and an actual value of the parameter in the steady state from a deviation between a target value and an actual value of the parameter; and An engine control device comprising: torque control means for controlling engine torque according to an output of an amount setting means. 2. An engine control device for controlling an actual filling amount such that the filling amount of the engine at the time of idling converges to a target filling amount, a filling amount detecting means for detecting the filling amount of the engine, and a load on the engine. A target filling amount setting unit that sets a target value of the filling amount according to a state, a load change determining unit that determines a change in the load state from a change in the target filling amount, and an output of the load change determining unit. A steady state deviation detecting means for detecting a deviation between the target filling amount and the actual filling amount in a steady state where the change in the load state is small, and receiving an output of the load determining means, and when the change in the load state is equal to or more than a predetermined value. A transient deviation detecting means for detecting a deviation between the target filling amount and the actual filling amount; and a target filling amount in the steady state based on a deviation between the target filling amount and the actual filling amount when the change in the load state is equal to or more than a predetermined value. And actual filling volume Correction amount setting means for setting a correction amount of the filling amount control based on a value obtained by subtracting a deviation from the correction amount, and filling amount control means for controlling a filling amount of the engine according to an output of the correction amount setting means. An engine control device characterized by the above-mentioned. 3. An engine control device for controlling an actual filling amount so that the filling amount of the engine at the time of idling converges to a target filling amount, a filling amount detecting means for detecting the filling amount of the engine, and a load on the engine. A target filling amount setting unit that sets a target value of the filling amount according to a state, a load change determining unit that determines a change in the load state from a change in the target filling amount, and an output of the load change determining unit. A steady state deviation detecting means for detecting a deviation between the target filling amount and the actual filling amount in a steady state where the change in the load state is small, and receiving an output of the load determining means, and when the change in the load state is equal to or more than a predetermined value. A transient deviation detecting means for detecting a deviation between the target filling amount and the actual filling amount; and a target filling amount in the steady state based on a deviation between the target filling amount and the actual filling amount when the change in the load state is equal to or more than a predetermined value. And actual filling volume Correction amount setting means for setting a correction amount for ignition timing control based on a value obtained by subtracting the deviation from the above, and ignition timing control means for controlling the ignition timing of the engine according to the output of the correction amount setting means. An engine control device characterized by the above-mentioned. 4. The engine control device according to claim 3, further comprising a correction continuation period extending means for continuing the ignition timing correction for a predetermined period when the load state is equal to or more than a predetermined value even after the change in the load state does not exceed the predetermined value. .