JPS623146A - Idle rotation learning controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent deterioration of engine operating performance, in a system where the idle rotation is learning controlled, by executing different learning control with correspondence to the on/off condition of electric load and stopping the learning control upon turning on of electric load. CONSTITUTION:It is provided with means B for setting the basic control level of idle control valve A and means C for setting the correcting quantity of feedback with correspondence to the difference between the target idle rotation and the actual idle rotation. While first and second memory means D, E for storing the correcting quantity of learning in correspondence with the engine operating condition are provided to retrieve the correcting quantity from one memory upon detection of turning-on of electric load through electric load detecting means F while from the other memory upon detection of turning-off. The retrieved correcting quantity of learning is updated through updata means H as a new correcting quantity thus to operate the control level through operat ing means I on the basis of said basic control quantity, feedback correcting quantity and learning corrective quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a learning control device for the idle speed of an internal combustion engine.

(Prior art) As an idle speed control device for an internal combustion engine, for example, a sixth
As shown in the figure, an idle control valve (ISO valve) 3 is installed in the middle of the auxiliary air passage 2 that bypasses the throttle valve 1.
Some systems are equipped with a system that adjusts the amount of auxiliary air to control the idle speed. The idle control valve is a rotary set, and pulse signals are sent to a valve opening coil and a valve closing coil (not shown) in an inverted state, and the opening degree is adjusted according to the duty ratio of the pulse signal. be done. In addition, 4 is an SP1 type fuel injection valve, 5
is a hot wire air flow meter, and 6 is a blow-by gas reflux pipe.

Regarding the feedback control of the idle speed, the target speed depends on the water temperature detected by the water temperature sensor, and the actual idle speed (hereinafter the actual speed) detected by the rotation angle signal from the crank angle sensor or the signal from the ignition coil. A feedback correction amount is determined in order to control the idle rotation speed (hereinafter referred to as the target rotation speed) by adding correction to the control value at that time if there is a difference.

The value of the feedback correction amount is changed by integral control or proportional-integral control to achieve stable control. That is, the target rotation speed and the actual rotation speed are compared, and if the actual rotation speed is lower (higher) than the target rotation speed, the feedback correction amount is increased (decreased) by a small amount.

However, when the actual rotational speed deviates from the target rotational speed, if the deviation in the correlation between the open lube duty and the target rotational speed is corrected by feedback control, it takes time to settle down to the original target rotational speed. This may lead to the engine stalling or the like.

In addition, in order to solve this problem, the integral constant of the integral control when setting the feedback correction amount is increased (this will cause hunting, over (under) shoot, etc., resulting in unstable idle rotation and engine stall due to a drop in rotation. There are problems such as the occurrence of

Therefore, by correcting the basic control value through learning and correlating it with the target rotation speed, it is possible to eliminate the correlation deviation and quickly control the idle rotation speed, and also to adjust the integral constant during feedback control. Japanese Patent Laid-Open Publication No. 59-211738 has already proposed a device that can be made smaller to improve the stability of idle rotation.

That is, in the operating region where idle rotation speed control is performed, the feedback correction amount l5Cfb is set by proportional-integral control based on the actual rotation speed and the target rotation speed.

Further, the previous learning correction amount l5C1e stored in the RAM is searched from the actual rotation speed. Then, the feedback correction amount l5Cfb and the previous learning correction amount l5C retrieved
Weighted average with 1e [(I 5Cfb+ CM −1)
x I 5C1e) /Ml to obtain a new learning correction amount and update the learning correction amount stored in the RAM to this new learning correction amount. The flowchart of such a conventional example is shown in the seventh section.
As shown in the figure.

<Problems to be Solved by the Invention> However, in such a conventional learning control device, when controlling the idle rotation speed, a new learning correction amount obtained from the feedback correction amount and the previous learning correction amount is used to store RAM. The stored value is updated, so if learning control is performed continuously during night driving in the rain or when there is a large electrical load such as the front lights or electric heater, the electrical load will be turned off. The amount of feedback correction increases compared to when the controller is in use. As a result, the new learning correction amount obtained from the feedback correction amount and the previous learning correction amount will also be larger than when the electric load is OFF, so after the learning control when the electric load is ON has progressed, the electric load is turned OFF and the electric load is turned ON. If idle speed control is performed based on the learning correction amount during engine operation, the idle speed will rise for a predetermined period of time as shown in FIG. 8 immediately after the electric load is turned off, deteriorating the engine operating performance.

The present invention was made in view of the above-mentioned circumstances, and is capable of stably controlling the actual rotation speed by suppressing the increase in the actual rotation speed immediately after the electric load is turned off, regardless of whether the electric load is ON or OFF. An object of the present invention is to provide a learning control device for the idle speed of an internal combustion engine.

<Means for solving the problem> For this reason, the first invention, as shown in FIG. Means B; Feedback correction amount setting means C that compares the target idle speed set based on the engine operating state with the actual idle speed and sets the feedback correction amount; first and second storage means E for storing the learning correction amount; electrical load detection means F for detecting ON/OFF states of the electrical load of the engine; and the first and second storage means E when the electrical load is ON. , E, and a learning correction amount search means G for searching the learning correction amount in the other storage means based on the engine operating state when the electric load is OFF, and the searched learning correction amount and the feedback correction amount. a first or second storage means in which a new learning correction amount is set and the retrieved learning correction amount is stored, an updating means H for updating the data of E, and the basic control value. It includes a control value calculating means I that calculates a control value based on a feedback correction amount and a learning correction amount, and a control means J that controls the idle control valve A based on the calculated control value.

Further, as a second invention, as shown in FIG. 2, a basic control value setting means B for setting a basic control value of the idle control valve A that is set based on the engine operating state; a feed bank correction amount setting means C for setting a feedback correction amount by comparing a target idle rotation speed and an actual idle rotation speed; and a storage means for storing a learning correction amount set according to an engine operating state. A learning correction amount search means searches the learning correction amount in the storage means according to the engine operating state, sets a new learning correction amount based on the searched learning correction amount and the feedback correction amount, and performs a new learning correction. updating means M for updating the data in the storage means based on the amount; first control value calculating means N for calculating the control value based on the basic control value, the feedback correction amount and the learning correction amount; An electric load detection means F detects the ON/OFF state of the load, and a learning control means 0 stops the learning operation by the learning correction amount search means and update means M when the electric load is ON, and the learning operation is stopped. Sometimes, a second control value calculation means P calculates a control value based on a basic control value and a feedback correction amount, and a second control value calculation means P calculates a control value based on the control value calculated by the first and second control value calculation means N, P. and a control means Q for controlling the idle control valve A. In this way, the learning control is advanced by separate storage means when the electric load is turned on and when the electric load is turned off, or when the electric load is turned on.
Turn off the electrical load by stopping learning control at certain times.
This suppresses the increase in idle speed that occurs immediately after the engine is turned on, and prevents deterioration in engine performance.

<Example> Embodiments of the present invention will be described below based on the drawings.

3 and 4 show an embodiment of the first invention.

In FIG. 3, 11 is a CPU, and 12 is a P-ROM.

13 is 0MO3-RAM as first and second storage means.
, 14 is an address decoder. Note that a backup power supply circuit is used for the RAM 13 in order to retain the stored contents even after the key switch is turned off.

Analog input signals to the CP Ull for controlling the idle control valve 3 include a water temperature signal from the water temperature sensor 15, a throttle opening signal from the throttle sensor 16, and a battery voltage from the battery 17, and these are analog inputs. It is designed to be input via an interface 18 and an A/D converter 19. 20 is an A/D conversion timing controller.

Digital input signals include starter switch 21, idle switch 22 . There are ON/OFF signals from a neutral switch 23 and an air conditioner switch 24, and these are inputted via a digital input interface 25.

In addition, a reference signal every 180 degrees and a position signal every 1 degree from the crank angle sensor 26 are inputted via a one-shot multi-circuit 27, for example. Further, a vehicle speed signal from a vehicle speed sensor 28 is inputted via a waveform shaping circuit 29.

The input signal from the CPU II (pulse signal to the idle control valve 3) is sent to the valve opening coil 3 of the idle control valve 3 in a mutually inverted state via the phase inversion driver 30.
a and the valve closing coil 3b.

Further, an ON/OFF signal from an electric load switch 31 as an electric load detection means that outputs an H signal when the front light and electric heater are turned on is inputted to the CPU Ull via the digital input interface 25.

Here, the CPU II performs input/output operations and calculations according to a program (stored in the ROM 12) based on the flowchart shown in FIG. It is designed to perform processing, etc.

Here, the CPU II serves as a basic control value setting means, a feedback correction amount setting means, a learning correction amount retrieval means, an updating means, and a control value calculation means, and the CPU 11 and the phase inversion driver 30 constitute a control means.

Next, the flowchart shown in FIG. 4 will be explained.

In S21, the water temperature Tw detected by the water temperature sensor 15 is
The basic control value l5Cts4 is set from . This setting may be performed by storing a map of the basic control value ISCtw using the water temperature Tw as a parameter in advance in the ROM 12 and searching from the map, or by calculation.

Further, in S22, various correction amounts l5Cet for the air conditioner, D range, acceleration/deceleration, etc. are set.

In S23, it is determined whether the ISO condition (area for performing ISO) is met. Specifically, the idle switch 22 that detects the fully closed state of the throttle valve is ON (the throttle valve is in the fully closed position), and the neutral switch 23 is ON (
When the transmission gear position is neutral),
Or the idle switch 22 is ON and the vehicle speed sensor 28
When the vehicle speed detected by is less than or equal to a predetermined value, it is assumed that the ISO condition is satisfied, and the process proceeds to the next step 324.

At 324, the target rotational speed N3 is set by searching or calculating from the water temperature Tw.

At step 325, the target rotation speed Ns is compared with the actual rotation speed N detected by the crank angle sensor 26°. Then, the feedback correction amount l5Cfb is set by integral control. That is, if N3>N, the feedback correction amount l5Cfb is increased by a predetermined amount from the previous value based on integral control in S26, and if Ns<N, the feedback correction amount l5Cfb is increased based on integral control in S27. In the case of 6NS''N (including the dead zone), the feedback correction amount l5Cfb is left at the previous value.

At step 32B, it is determined whether or not the electric loads such as the front light and the electric heater are in the ON state based on the output signal of the electric load switch 31, and when they are ON, the process advances to S29.

Then, the learning correction amount l5C1e stored in map 1 of the RAM 13 is searched from the actual rotation speed N. Here, all learning correction amounts at the time when learning has not started are given initial values.

In 330, it is determined whether a predetermined period of time has elapsed since the ISC condition was met in S23, and if YES, the process proceeds to 331.

In S31, the feedback correction amount l5Cfb and S2
Based on the learning correction amount ISC]e retrieved in step 9, a new learning correction amount is calculated using the following formula (M is a constant). Update the actual rotation speed and the corresponding data.

In S33, the basic control value ISO glaze and various correction amounts l5G
et, the feedback correction amount l5Cfb, and the new learning correction amount l5C1e to obtain the control value l5Cdy.

Then, a pulse signal with a duty ratio corresponding to the control value l5Cdy is applied to the valve opening coil 3a and valve closing coil 3b of the idle control valve 3 via the phase inversion driver 30.

If NO in S30, S3 is executed based on the previous learning correction amount.
In step 3, the control value tsctiy is determined.

Further, when it is determined in step 32B that the electric load is OFF, the process proceeds to step S34, and the learning correction amount l5CIθ stored in map 2 of the RAM 13 is retrieved based on the actual rotation speed N.

In S35, similarly to S30, it is determined whether a predetermined time has elapsed since the establishment of the ISO condition 323, and if YES, the 3
36, and in 836, the feedback correction amount l5
Based on Cfb and the learning correction amount l5C1e retrieved in step 329, a new learning correction amount is calculated in the same manner as in step 531 above.

In S37, data in map 2 of the RAM 13 in which the rotational speed corresponds to the actual rotational speed is updated to the new learning correction amount l5C1e, and then the process proceeds to S33, where a control value l5Cdy is calculated.

Note that if the ISC condition is not satisfied in S23, the process proceeds to S38.
Then, the control value l5Cdy is determined by adding the basic control value rsctw and the various correction amounts l5Cet.

As explained above, since the learning control is performed in different maps of RAM 13 depending on the ON/OFF status of electrical loads such as front lights and electric heaters, the idle speed can be controlled with good responsiveness. It is possible to suppress the increase in idle speed that conventionally occurs immediately after turning off the engine, and prevent deterioration in engine operating performance. Further, according to this configuration, it is possible to suppress a decrease in the idle rotation speed (see FIG. 8) that occurs immediately after the electric load is turned on.

FIG. 5 shows a flowchart corresponding to an embodiment of the second invention. Note that the same steps as in FIG. 4 are assigned to the same controls as in the flowchart in FIG. 4, and the explanation thereof will be omitted.

When the electric load is determined to be OFF in 32B, S4
The learning correction amount l stored in a single map in RAM at 0
After searching 5C1e based on the actual rotation speed N, I at 341
It is determined whether a predetermined period of time has elapsed since the SC condition was satisfied.

When a predetermined period of time has elapsed, a new learning correction amount l5 is added in 342.
O1e is calculated in the same manner as in the above embodiment, and data in the RAM map is updated to the calculated new learning correction amount l5C1e (S43). Then, in S33, the control value l5Cdy is updated.
Calculate.

Further, when it is determined in 32B that the electric load is ON, the process proceeds to S44 without performing learning control, and the basic control value ISCtw, various correction amounts l5Cet, and feedback correction amounts l5Cfb are added to obtain the control value rscdy. .

As explained above, learning control is stopped when the electrical load is turned on, and learning control is performed when the electrical load is turned off. Idle rotation speed control is performed based on the learning correction amount before turning on. For this reason, the actual rotation speed can be controlled to the target rotation speed with good responsiveness, so that an increase in the idle rotation speed can be suppressed.

<Effects of the Invention> As explained above, the present invention can
Another learning control is performed depending on the F state, or the electrical load is
Since the learning control is stopped when the power is turned off, the actual rotation speed can be controlled to the target rotation speed with good responsiveness immediately after the electrical load is turned off, thereby suppressing the rise in idle rotation speed that previously occurred. This makes it possible to prevent deterioration of engine operating performance.

[Brief explanation of drawings]

1 is a claim correspondence diagram of the first invention, FIG. 2 is a claim correspondence diagram of the second invention, FIG. 3 is a block diagram showing an embodiment of the first invention, FIG. The figure is the second
FIG. 6 is a sectional view of a throttle chamber showing an example of an idle control valve, FIG. 7 is a flowchart of a conventional example, and FIG. 8 is a diagram for explaining the operation of the conventional example. . 3...Idle control valve 11...CPU 1
3...RAM 30...Phase reversal dry un-3
1... Electrical load switch patent applicant Fujio Sasashima, agent and patent attorney for Japan Electronics Co., Ltd. Figure 6 Figure 8, □ Actual rotation speed

Claims (2)

[Claims] (1) In an internal combustion engine equipped with an idle control valve that controls the intake flow rate of an auxiliary air passage that bypasses the throttle valve, basic control value setting that sets the basic control value of the idle control valve that is set based on the engine operating state. means, a feedback correction amount setting means for setting a feedback correction amount by comparing a target idle speed set based on the engine operating state and an actual idle speed, and a learning correction set according to the engine operating state. first and second storage means for storing the amount; electrical load detection means for detecting the ON/OFF state of the electrical load of the engine; and when the electrical load is ON, the learning correction amount of one of the first and second storage means is stored. Electrical load O
At the time of FF, a learning correction amount search means searches the learning correction amount in the other storage means according to the engine operating state, and a new learning correction amount is set based on the searched learning correction amount and the feedback correction amount, and a new learning correction amount is set. updating means for updating data in the first or second storage means in which the learning correction amount retrieved as the correction amount is stored; and calculating a control value based on the basic control value, the feedback correction amount, and the learning correction amount. 1. A learning control device for an idle rotation speed of an internal combustion engine, comprising a control value calculation means and a control means for controlling the idle control valve based on the calculated control value. (2) In an internal combustion engine equipped with an idle control valve that controls the intake flow rate of an auxiliary air passage that bypasses the throttle valve, basic control value setting that sets the basic control value of the idle control valve that is set based on the engine operating state. means, a feedback correction amount setting means for setting a feedback correction amount by comparing a target idle speed set based on the engine operating state and an actual idle speed, and a learning correction set according to the engine operating state. a storage means for storing the learning correction amount; a learning correction amount search means for searching the learning correction amount in the storage means according to the engine operating state; and a new learning correction amount based on the retrieved learning correction amount and the feedback correction amount. updating means for updating the data in the storage means with the set new learning correction amount; and a first calculating means for calculating a control value based on the basic control value, the feedback correction amount, and the learning correction amount.
a control value calculating means, an electrical load detecting means for detecting the ON/OFF state of the electrical load of the engine, a learning control stopping means for stopping the learning operation by the learning correction amount searching means and the updating means when the electrical load is ON; a second control value calculation means for calculating a control value based on the basic control value and the feedback correction amount when the operation is stopped; and a control value calculated by the first and second control value calculation means. A learning control device for idle rotation speed of an internal combustion engine, comprising: control means for controlling the idle control valve.