JPS60247025A - Learning control device for rotational speed of internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance the stability of idle rotational speed to prevent engine stall upon transient operation in a feed-back control for idle rotational speed, by ceasing the learning of feed-back compensating amounts for predetermined time periods after starting and stopping. CONSTITUTION:An idle control valve is disposed in an auxiliary air passage bypassing a throttle vavle. A compemsating amount setting means B compares a desired rotational speed of an engine with an actual rotational speed thereof to set a feed-back compensating amount by means of an integration control A leaning ceasing means H ceases the data up-dating operation of the leaning control for predetermined time after starting and stopping to continuously carry out a satisfactory leaning control after starting. Thus, it is possible to enhance the stability of idle rotational speed, thereby it is possible to prevent engine stall and to enhance the fuel consumption rate.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> 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 fourth
As shown in the figure, there is an idle control valve (ISO pulp) 3 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
6 is a hot wire air flow make, and 6 is a blow-high gas reflux pipe.

By the way, the duty ratio of the pulse signal to the idle control valve is determined by the control value l5Cdy calculated by the following equation. Note that the unit of this control value is expressed in (%), and is output as the percentage of time that the valve opening coil is ON.

ISCdy=ISCtw+l5Cet+l5CfbHere, ISCtw is the basic control value depending on the cooling water temperature (hereinafter referred to as water temperature), ISCet is the various correction amounts for the air conditioner, D range, and acceleration/deceleration correction, and l5cfb is the idle rotation speed feedback control (described later). This is the feedback correction amount for ISO).

Regarding the feedbank control of the idle rotation speed, the target rotation speed depends on the water temperature detected by the water temperature sensor, and the actual rotation speed detected by the rotation angle signal from the crank angle sensor or the signal from the ignition coil (hereinafter referred to as the actual rotation speed). If there is a difference, a correction is made to the control value at that time to control the target rotation speed, and for this reason, a feedback correction amount l5Cfb is determined. .

The value of the feedback correction amount l5Cfb 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 than the target rotation speed (higher than the target rotation speed), the feedback correction amount l5Cfb is increased (decreased) little by little.

By the way, the open loop duty (feed bank correction amount l5Cfb) corresponding to the basic control value ISCtw (or the added value of this and the correction amounts l5Ctr and l5Cet)
If the rotation speed obtained by the control value I S Cdy when is the reference value completely matches the target rotation speed, the feedback correction amount l5Cfb will remain at the reference value, so feedback control is not necessary. In reality, feedback control is performed because the correlation may deviate due to clogged throttle chambers, variations in parts, etc.

However, if the correlation between the open-loop duty and the target rotational speed is off, when the actual rotational speed deviates from the target rotational speed, feed puncture control is used to compensate for the deviation in the correlation between the open-loop duty and the target rotational speed. It takes time to correct, that is, to settle down to the original target rotation speed. This may lead to the engine stalling or the like. In addition, in order to solve this problem, if the integral constant of integral control is increased when setting the feedback correction amount l5Cfb, hunting, over (under) shoot, etc. will occur, resulting in unstable idling rotation and engine stall due to drop in rotation. There are problems that arise.

Therefore, by correcting the open-loop duty, that is, 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 control the feed bank control. The applicant of the present invention has already filed an application for a system in which the stability of idling rotation can be improved by making it possible to reduce the integral constant at the time of idling.

However, when starting the engine (particularly when starting at a low temperature) and immediately after starting, friction is large due to oil viscosity and lubrication delays, making it difficult for the engine speed to increase.As shown in Figure 5, the integral of feedhack correction is If the correction amount is large and this value is learned, it will have an adverse effect on the learning correction amount in the stable state that was learned until the previous time, resulting in a decrease in the effectiveness of the learning control.

<Problems to be Solved by the Invention> The present invention has been made in view of the above points, and is designed to continuously perform good learning control after startup without adversely affecting the learning correction amount during startup. The purpose is to solve the above problems.

<Means for Solving the Problems> For this reason, the present invention, as shown in FIG. a basic control value setting means A that sets a basic control value setting means A, and a feedback correction amount setting means that sets a feed hack correction amount by integral control by comparing the target engine rotation speed and the actual rotation speed of the engine, which are set based on the engine operating state. B, a learning correction amount search means for searching the learning correction amount stored in the map C of the RAM according to the engine operating state, and adding a predetermined percentage of the deviation amount from the reference value of the feed bank correction amount to the learning correction amount. a learning correction amount correcting means E for setting a new learning correction amount by updating the data of the same engine operating state in the RAM; a means F for detecting the starting state of the engine; and a means F for detecting the starting state of the engine; a learning stop means H which stops the data update operation of the learned correction amount at the time of starting and for a certain period of time after the start; and a learning stop means H which adds the feedback correction amount and the learning correction amount to the basic control value. A configuration comprising a control value calculation means (1) for calculating a control value of a duty ratio of a pulse signal based on the calculated control value, and a pulse signal output means (J) for outputting a pulse signal of a duty ratio based on the calculated control value to an idle control valve. shall be.

In the second aspect of the invention, the predetermined time period after startup for stopping the learning correction amount data updating operation of the learning stop means H in the first aspect is set in accordance with the temperature state of the engine.

(Function) With this configuration, learning is stopped during startup and during a predetermined period of time after startup when the engine friction is large and the feedhack correction amount cannot be properly learned, and the integral correction amount is stabilized. Since learning is started from , fluctuations in the learning correction amount can be suppressed, and good learning can be continued.

<Example> Examples will be described below.

Figure 2 shows the hardware configuration.

11 is a CPU, 12 is a P-ROM, 13 is a CuO2-RAM for learning control, and 14 is an address decoder. Note that a bank amplifier power supply circuit is used for the RAM 13 in order to retain the stored contents even after the key switch is turned off.

The analog input signal to the CPU II for controlling the idle control valve 3 is water from the water temperature sensor 15. & (
t, the throttle opening signal from the throttle sensor 16, and the battery voltage from batch January 7, which are connected to the analog input interface 18 and the A/D converter 19.
It is now input via the .

20 is an A/D conversion timing controller.

Digital input signals include starter switch 21, idle switch 22 . 0N-OFF from neutral switch 23 and air conditioner switch 24 (No. 8 is available,
These are inputted via the digital input interface 25.

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

The input signal from C'PUII (pulse signal to the idle control valve 3) is passed through the phase inversion driver 30 to the valve opening coil 3a and valve closing coil 3b of the idle control valve 3 in a mutually inverted state. It is designed to be sent to

Here, the CP Ull performs input/output operations as well as in accordance with a program (stored in the ROM 12) based on the flowchart shown in FIG. It is designed to perform calculation processing, etc.

Next, the flowchart shown in FIG. 3 will be explained.

At Sl, a basic control value ISCtw is set from the water temperature Tw detected by the water temperature sensor 15. In addition, this setting is
A map of the basic control value l5Cby using the water temperature Tw as a parameter may be stored in advance in the ROM 12, and the determination may be performed by searching from the map or by calculation.

In addition, if necessary, the transient correction amount l5Ctr is set to 83 in S2.
Set other correction amounts l5Cet.

Further, in S4, a learning correction 1iIscle is searched from the water temperature Tw. In addition, the learning correction amount l using the water temperature Tw as a parameter
The map of 5C1e is stored in the rewritable RAM 13, and all initial values are given at the time when learning has not started.

In S5, it is determined whether or not the SC condition (area where ISC is performed) 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 0N (1
-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 86.

In S6, the target rotational speed Ns is set by searching or calculating from the water temperature Tw.

In S7, the target rotation speed Ns and the actual rotation speed N detected by the crank angle sensor 26 are compared. Then, the feedback correction amount l5Cfb is set by integral control.

That is, if Ns>N, the feedback correction amount l5Cfb is increased by a predetermined amount from the previous value based on integral control in S8, and if Ns<N, the feedbank correction amount l5Cfb is increased based on integral control in S9. is decreased by a predetermined amount from the previous value. When N5=N (including the dead zone), the feedback correction amount l5Cfb is kept at the previous value.

In S10, it is determined whether or not the starter switch 21 is in a starting (cranking) state depending on whether it is ON or not, and if this determination is NO, the process proceeds to Sll.

Sll searches for a predetermined time after startup at which learning is to be stopped, as will be described later, based on the water temperature Tw.

In S12, after the SIO determination is NO, that is,
After starting, it is determined whether a predetermined time set in S12 has elapsed, and when this determination is YES, the process proceeds to S13.

In S13, the reference value (
Deviation amount ΔrsCfb (
Based on ISCfb-IC), the learning correction amount l5
C1e is updated as shown in the following equation.

I S C1e+I S C1e+Δ1.5Cfb/M
(However, M is a constant, and M>1) The new learning correction amount l5C1e is written to the corresponding water temperature in the RAM 13, and the data in the RAM 13 is updated. Next, the process advances to S14.

On the other hand, during start-up when the SIO judgment is YES and after the start-up period when the S10 judgment is NO, the data of the learning correction amount l5C1e is updated in 313, that is, the process proceeds to 314 without performing learning. move on.

In this way, learning starts when a predetermined period of time has elapsed after starting the engine.

In step 314, the control value l5Cdy is calculated using the following equation.

I5Cdy=ISCtw+I5Ctr+I
5Cet+ E 5C1e+ I 5Cfb Note that when the ISC condition is not satisfied in S5, the process jumps to S14 and calculates the control value rscdy without performing feedback control and learning.

The control value l5Cdy is calculated above, and this control value l5C
A pulse signal with a duty ratio corresponding to dy 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.

In addition to the idle control valve of the type shown in FIG. 4, the present invention is applicable to control of various types of idle control valves that are opened and closed by pulse signals.

Further, in this embodiment, an embodiment of the second invention is shown in which a predetermined time after startup for stopping learning is set based on the water temperature Tw, but if this predetermined time is set constant, the first invention This is an example.

<Effects of the Invention> As explained above, according to the present invention, in feed-hack control of the idle rotation speed, engine friction is large and the integral correction amount of the feedback correction amount obtained by integral control is large. Since learning of the feedback correction amount is stopped during the adjustment period after startup, good learning control can be performed continuously, and the stability of idle rotation due to learning is increased to prevent engine stalling during transient operation.

The effect of truly promoting improvements in fuel efficiency, etc. can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a hardware configuration diagram showing an embodiment of the present invention, FIG. 3 is a flowchart of the same as above, and FIG. 4 is a throttle diagram showing an example of an idle control valve. FIG. 5, a cross-sectional view of the chamber, is a diagram showing the characteristics of the feed bank correction amount and engine speed immediately after starting by a conventional learning control device. ■... Throttle valve 2... Auxiliary air passage 3...
Idle control valve 11...CPU 12...P-P
OM 13...CMO,%-RAM 15...Water temperature sensor 21...Starter switch 22...Idle switch 23...Neutral switch 26
...Crank angle sensor 28...Vehicle speed sensor Patent applicant Japan Electronics Co., Ltd. Patent attorney Fujio Sasashima

Claims (1)

[Claims] In an internal combustion engine, an auxiliary air passage that bypasses an ill throttle valve is provided with an idle control valve that is driven by a pulse signal and whose opening degree is adjusted according to its duty ratio. Basic control value setting means for setting the basic control value of the signal duty ratio, and feedback correction for setting the feedback correction amount by integral control by comparing the target rotation speed set based on the engine operating state and the actual rotation speed. a learning correction amount searching means for searching a learning correction amount stored in a RAM according to an engine operating state; and adding a predetermined proportion of a deviation amount from a reference value of the feedback correction amount to the learning correction amount. a learning correction amount correcting means for setting a new learning correction amount and updating data of the same engine operating state in RAM; a means for detecting the starting state of the engine; and a starting means for measuring the elapsed time after starting the engine. elapsed time measuring means; learning stop means for stopping the data update operation of the learning correction amount at the time of startup and for a certain period of time after startup; and the duty of the pulse signal by adding the feed bank correction amount and the learning correction amount to the basic control value. An idle rotation of an internal combustion engine, comprising: a control value calculation means for calculating a ratio control value; and a pulse signal output means for outputting a pulse signal of a duty ratio based on the calculated control value to an idle control valve. Number learning control device. (2) In an internal combustion engine equipped with an idle control valve in an auxiliary air passage that bypasses a throttle valve, the idle control valve is driven by a pulse signal and its opening degree is adjusted according to its duty ratio, and the duty ratio of the pulse signal is determined based on the engine operating state. basic control value setting means for setting a basic control value; and feedback correction amount setting means for setting a feedback correction amount by integral control by comparing a target rotation speed set based on the engine operating state and an actual rotation speed. a learning correction amount retrieval means for searching the learning correction amount stored in the RAM according to the engine operating state; A learning correction amount correcting means for setting a learning correction amount and updating data of the same engine operating state in RAM, a means for detecting a starting state of the engine, and an elapsed time after starting for measuring the elapsed time after starting the engine. a measuring means, a learning stop means for stopping the data update operation of the learning correction amount for a predetermined time set according to the temperature state of the engine at the time of starting and after starting, and adding the feedback correction amount and the learning correction amount to the basic control value. and a pulse signal output means for outputting a pulse signal having a duty ratio based on the calculated control value to the idle control valve. A learning control device for the idle speed of an internal combustion engine.