JPH06146988A - Learned value controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To ensure relatively safe driving condition in the case where feeding from a battery is interrupted, and even within a period from the starting of an internal combustion engine to preparation of updating condition of learned values. CONSTITUTION:A trip meter 30 mechanically driven, for detecting summed running distance, is connected with an ECU 41. When the feeding from a battery 16 to the ECU 41 is interrupted, an air fuel ratio initially learned value is calculated based on the summed running distance, and the value is adopted as an air fuel ratio initially learned value when an engine 1 is started. Although previous air fuel ratio learned values are eliminated by the interruption of feeding from the battery 16 to the ECU 41, the data on the summed running distance is mechanically stored. Since an air fuel ratio initially learned value calculated based on the data corresponds to the degree of the change in time elapse of the engine 1, it becomes a value close to that directly before the interruption of the feeding from the battery 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a learning value used for various controls of an internal combustion engine such as air-fuel ratio control and idle speed control, and is updated according to a deviation between a basic operating state and a current operating state. The present invention relates to a control device for a learning value stored in a storage means that is powered by a battery.

[0002]

2. Description of the Related Art Conventionally, in various control of an internal combustion engine such as air-fuel ratio control and idle speed control, feedback control is performed and learning control is performed for the purpose of further improving control accuracy. This learning control means that the learning value according to the current operating state is reflected in, for example, the fuel injection time. This learning value is updated when a certain condition is met according to the deviation between the predetermined basic operating state of the engine and the current operating state of the engine. Further, the learned value is stored in the storage means of the control device which is supplied with power from the battery. Such a learned value is not erased even if the ignition key is turned “off”, that is, the engine rotation is stopped.

However, when the power supply from the battery to the storage means is interrupted, such as when the battery is replaced, the learning value is erased. Then, when the engine is restarted, a constant initial value is set as a new learning value instead of the deleted learning value. Therefore, if there is a large disparity between the initial value and the learning value immediately before being erased, it takes time for the learning value to return to the value immediately before being erased, and the learning value is restored. Until then, the operating condition becomes unstable.

Therefore, as a technique for dealing with the above problem, for example, the technique disclosed in Japanese Patent Laid-Open No. 61-28739 can be mentioned. In this technique, after the learning value stored in the storage means is erased due to the interruption of power supply, a constant initial value is set as the learning value as described above. Then, the update speed of the learning value is accelerated only for a predetermined time after the engine is started. This can shorten the time until the learning value immediately before being erased is restored.

[0005]

However, in the above-mentioned conventional technique, the learning value is still set to a constant initial value after being erased by interruption of power supply. Since the learned value is not updated until a predetermined update condition is met, it takes some time after the engine is restarted to return to the value just before the learned value is erased. During the time until the engine is restored, for example, a sufficient amount of fuel may not be obtained due to the valve deposit, which may hinder the engine rotation speed from increasing. And as a result, engine stall occurs without obtaining sufficient engine speed, etc.
There was a risk that the operating conditions would still be unstable.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a basic operating state of an internal combustion engine,
The control device for the learning value updated in accordance with the deviation from the current operating state and stored in the storage means powered by the battery determines that the power supply from the battery to the storage means is interrupted, and the internal combustion engine An object of the present invention is to provide a learning value control device for an internal combustion engine, which is capable of ensuring a relatively stable operating state even after the start of the engine until the conditions for updating the learning value are met.

[0007]

In order to achieve the above object, in the present invention, as shown in FIG. 1, a predetermined basic operating state of the internal combustion engine M1 and a current operating state of the internal combustion engine M1. Battery M is updated according to the deviation from
In the control device for the learning value stored in the storage means M3 supplied from the power source 2, the change degree detecting means M4 for indirectly detecting the degree of change with time of the internal combustion engine M1 and the battery M
2 to the storage unit M3, the determination unit M5 that determines whether the power supply to the storage unit M3 has been interrupted, and the determination unit M5 that determines the battery M2.
If it is determined that the power supply to the storage unit M3 is interrupted by the internal combustion engine M1, the temporal change degree detection unit M is started when the internal combustion engine M1 is started.
The gist is that it is provided with an initial value calculation means M6 for calculating an initial value of the learning value based on the detection result of No. 4.

[0008]

According to the above construction, as shown in FIG. 1, the degree of change over time of the internal combustion engine M1 is indirectly detected by the change over time detecting means M4. Further, the determination means M5 determines whether or not the power supply from the battery M2 to the storage means M3 has been interrupted. When it is determined that the power supply to the storage unit M3 is interrupted, the initial value calculation unit M6 calculates the initial value of the learning value based on the detection result of the temporal change degree detection unit M4 when the internal combustion engine M1 is started. To be done.

Here, by interrupting the power supply from the battery M2 to the storage means M3, the learning value stored in the storage means M3 is erased. However, since the initial value calculated at this time and newly adopted as the learning value is a value corresponding to the degree of change over time of the internal combustion engine M1,
A value close to the learned value immediately before the power supply from the battery M2 to the storage unit M3 is interrupted can be taken. Therefore, even before the conditions for updating the learned value are met, the operating state of the internal combustion engine M1 is ensured to be close to the state immediately before the interruption of power supply. If the update conditions are met, the learned value can be returned to the learned value immediately before the power supply is interrupted in a relatively short time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the learning value control device for an internal combustion engine according to the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic configuration diagram showing a learning value control device for an engine mounted on a vehicle in this embodiment. As shown in FIG. 1, an engine 1 as an internal combustion engine takes in outside air from an air cleaner 3 via an intake passage 2. Further, the engine 1 takes in the outside air and at the same time takes in fuel injected from an injector 4 provided for each cylinder near the intake port 2a. Then, the mixture of the taken-in fuel and the outside air is introduced into the combustion chamber 1a via the intake valve 5 provided for each cylinder, and the combustion chamber 1a is exploded and burned to obtain a driving force. Also, the exhaust gas after explosion and combustion is
From the combustion chamber 1a, an exhaust valve 6 is introduced to an exhaust passage 7 where the exhaust manifold for each cylinder is assembled, and the exhaust passage 7 is exhausted to the outside.

In the middle of the intake passage 2, there is provided a throttle valve 8 which opens and closes in conjunction with the operation of an accelerator pedal (not shown). And this throttle valve 8
The amount of intake air to the intake passage 2 is adjusted by opening and closing. Also, on the downstream side of the throttle valve 8,
A surge tank 9 for smoothing the pulsation of intake air is provided.

A bypass intake passage 10 is provided in the intake passage 2 so as to connect the upstream side and the downstream side of the throttle valve 8 to each other. Then, in the middle of the bypass intake passage 10, a linear solenoid idle speed control for adjusting the flow rate of the air flowing through the bypass intake passage 10 is performed.
A control valve (ISCV) 11 is provided. When the throttle valve 8 is closed and the engine 1 is in an idle state, the ISCV 11 is feedback-controlled by duty control to open and close to adjust the air flow rate in the bypass intake passage 10. With this, the idle rotation speed of the engine 1 is controlled.

An intake air temperature sensor 21 for detecting an intake air temperature THA is provided near the air cleaner 3 in the intake passage 2. In addition, in the vicinity of the throttle valve 8,
A throttle sensor 22 that detects the opening degree (throttle opening degree) θ is provided, and an idle switch 23 that “turns on” to detect an idle state when the throttle valve 8 is fully closed is provided. Further, the surge tank 9 is provided with an intake pressure sensor 24 that communicates with the surge tank 9 and detects the intake air pressure (intake pressure) PiM.

On the other hand, an oxygen sensor 25 for detecting the oxygen concentration OX in the exhaust is provided in the middle of the exhaust passage 7. Further, the engine 1 is provided with a water temperature sensor 26 that detects the temperature (cooling water temperature) THW of the cooling water.

An ignition signal distributed by a distributor 13 is applied to an ignition plug 12 provided for each cylinder of the engine 1. The distributor 13 is for distributing the high voltage output from the igniter 14 to each spark plug 12 in synchronization with the crank angle of the engine 1. The ignition timing of each spark plug 12 is the high voltage output timing from the igniter 14. Determined by

The distributor 13 is provided with a rotation speed sensor 27 for detecting the rotation speed (engine rotation speed) NE of the engine 1 from the rotation of a rotor (not shown) built in the distributor 13. Also,
The distributor 13 is also provided with a crank angle sensor 28 that detects a change in the crank angle of the engine 1 at a predetermined rate according to the rotation of the rotor.

Further, the engine 1 is provided with a starter 15 for applying a rotational force to the engine 1 by cranking at the time of starting the engine 1. Further, an ignition switch 29 is provided at the front of the vehicle compartment.
As is well known, the ignition switch 29 is connected to the battery 16 and is switched on / off by a key operation of a driver. Then, the ignition switch 29 outputs an ignition signal IG corresponding to the operation position.

At the same time, a trip meter 30 is provided at the front of the vehicle compartment as a means for detecting the degree of change over time for displaying the total traveling distance TD. In this trip meter 30, the drum of each digit for displaying the total travel distance TD is mechanically driven to rotate, and a digital switch type distance transmitting means (not shown) is provided on the back side of the display surface. There is. With this distance transmission means, the rotation status of the drum can be output as an electric signal.

Then, each of the sensors 21, 22, 24 ...
The operating state of the engine 1 including the traveling distance is appropriately detected by the switch 28, the switches 23 and 29, and the trip meter 30.

Further, each injector 4, ISCV 11 and igniter 14 are electronic control units (hereinafter simply referred to as "EC
U ”) 41 and is electrically connected to the ECU 41.
The drive timings of them are controlled by the operation of.
The ECU 41 constitutes storage means, determination means, and initial value calculation means.

The ECU 41 includes an intake air temperature sensor 21, a throttle sensor 22 and an idle switch 2 which are described above.
3, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 2
6, a rotation speed sensor 27, a crank angle sensor 28, an ignition switch 29, and a trip meter 30 are connected to each other. Therefore, the ECU 41 suitably controls the injector 4, the ISCV 11, the igniter 14, and the like based on the output signals from the sensors 21, 22, 24 to 28, the switches 23 and 29, the trip meter 30, and the like. Further, a battery 16 is connected to the ECU 41, and the power supply voltage is supplied from the battery 16 so that the ECU 41 can execute various controls.

Next, the structure of the ECU 41 will be described with reference to the block diagram of FIG. The ECU 41 includes a central processing unit (CPU) 42, a read-only memory (ROM) 43 in which a predetermined control program, maps, etc. are stored in advance, and a CPU 42.
Random access memory (RAM) 44 for temporarily storing the calculation results and the like, backup RAM 45 for storing previously stored data, and the like. In addition, the ECU 41
Is an external input circuit 46 and an external output circuit 47.
And the like are connected as a logical operation circuit by a bus 48.

The external input circuit 46 includes the intake air temperature sensor 21, the throttle sensor 22, and the idle switch 2 described above.
3, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 2
6, a rotation speed sensor 27, a crank angle sensor 28, an ignition switch 29, a trip meter 30, etc. are connected. Then, the CPU 42 reads output signals from the sensors 21, 22, 24 to 28, the switches 23 and 29, and the trip meter 30 as input values via the external input circuit 46. Then, the CPU 42 suitably controls the injector 4, the ISCV 11, the igniter 14, etc. connected to the external output circuit 47 based on these input values.

Further, each learned value in this embodiment is stored in the backup RAM 45 described above. Then, the battery 16 is removed,
When the power supply from the battery 16 to the ECU 41 is interrupted, the learned value is erased.

Next, of the various processes executed by the ECU 41, the process for performing the air-fuel ratio control will be described with reference to the flowcharts of FIGS. Therefore, first, the process of setting the initial air-fuel ratio learning value KG in the air-fuel ratio control when the power supply from the battery 16 to the ECU 41 is interrupted will be described with reference to the flowchart of FIG.

FIG. 4 shows an "initial learning value calculation routine" which is executed when the engine 1 is started, and is executed by a regular interruption every predetermined time. When the processing shifts to this routine, first, at step 101, it is judged based on the ignition signal IG from the ignition switch 29 whether or not the ignition has been switched from "off" to "on". Then, when the ignition is not switched from "OFF" to "ON", the subsequent processing is once ended. If the ignition is switched from "off" to "on", the next step 102
Move to.

In step 102, it is determined whether or not the battery standby flag F is "1". Here, the battery standby flag F is preset in another routine. That is, the battery 16
Is removed from the battery 16 and the ECU 4
When the power supply to 1 is interrupted, the battery standby flag F is set to "1", and when not, the flag F is set to "0". Then, if the battery standby flag F is not "1", it is determined that the power supply from the battery 16 to the ECU 41 has not been interrupted, and the subsequent processing is temporarily terminated. When the battery standby flag F is "1", the battery 1
Assuming that the power supply from 6 to the ECU 41 has been interrupted, the process proceeds to step 103.

In step 103, the rotation status of the drum is grasped from the distance transmission means of the trip meter 30,
The total traveling distance TD so far is read. At this stage, since the power supply from the battery 16 to the ECU 41 is interrupted, the data such as the air-fuel ratio learning value KG stored mainly in the backup RAM 45 has been erased. However, at least the data of the total travel distance TD is used as the trip meter 30 that is mechanically driven to rotate.
It is saved as the rotation status of the drum. Then, under this situation in which the power supply voltage of the battery 16 is being supplied to the ECU 41 again, the total traveling distance TD from the distance transmitting means is read as an electric signal.

Subsequently, at step 104, the air-fuel ratio initial learning value KG1 is calculated based on the total traveling distance TD read in this routine. This air-fuel ratio initial learning value KG1 is calculated based on the map shown in FIG. As is clear from the figure, in a region where the total traveling distance TD is equal to or greater than a certain value, the air-fuel ratio initial learning value KG1 becomes higher as the total traveling distance TD becomes longer.

Then, in step 105, the air-fuel ratio initial learning value KG1 calculated in this routine is set as the air-fuel ratio learning value KG, and in the next step 10
In 6, the battery standby flag F is reset to "0" and the subsequent processing is temporarily terminated.

As described above, in the "initial learning value calculation routine", the air-fuel ratio initial learning value KG1 is only once when the power supply from the battery 16 to the ECU 41 is interrupted and the ignition is turned "on". Is calculated.
This air-fuel ratio initial learning value KG1 is calculated according to the total traveling distance TD, and that value is set as the initial air-fuel ratio learning value KG.

Next, the processing for performing the air-fuel ratio control based on the air-fuel ratio learning value KG and the like will be described with reference to the flowchart of FIG. FIG. 6 shows an "air-fuel ratio control main routine" executed when performing the air-fuel ratio control, which is executed by a regular interrupt every predetermined time.

When the processing shifts to this routine, first, at step 201, the engine speed NE and the intake pressure PiM are read based on the detection signals from the rotation speed sensor 27 and the intake pressure sensor 24.

In step 202, the engine speed NE and intake pressure PiM read in this routine are read.
Based on, the basic injection time τBASE corresponding to the so-called basic injection amount is calculated. Here, the basic injection time τBAS
E is calculated based on the engine rotation speed NE and the intake pressure PiM by referring to a predetermined map (not shown).

Next, at step 203, the air-fuel ratio feedback correction coefficient F calculated by a separate routine.
Read AF. This air-fuel ratio feedback correction coefficient F
The AF is a separate routine in which the air-fuel ratio is calculated by the oxygen concentration OX or the like based on the detection signal from the oxygen sensor 25, and feedback control is appropriately performed depending on whether the air-fuel ratio is on the lean side or the rich side. Is.

In step 204, the air-fuel ratio learning value KG calculated by a separate routine including the above-mentioned "initial learning value calculation routine" is read. Here, this air-fuel ratio learning value KG is initially learned when the power supply from the battery 16 to the ECU 41 is interrupted, and as described above, the air-fuel ratio initial learning value KG1 calculated according to the total traveling distance TD. Is set as the air-fuel ratio learning value KG. After that, the air-fuel ratio learning value KG is set by a separate "learning value calculation routine". Briefly explaining this "learning value calculation routine",
First, various operating states such as whether the engine 1 is in the idling state or whether the intake pressure PiM is within a predetermined range are determined. Then, the air-fuel ratio learning value KG corresponds to the above-mentioned air-fuel ratio feedback correction coefficient FA only when the learning condition is satisfied according to the determination result.
It is appropriately updated and set according to F. The learning condition here is, for example, a condition that the air-fuel ratio feedback control is being executed, the cooling water temperature THW is equal to or higher than a predetermined temperature, and the intake air temperature THA is within a predetermined range.

Then, in step 205, the target injection time τ is calculated based on the basic injection time τBASE calculated in this routine and the air-fuel ratio feedback correction coefficient FAF and the air-fuel ratio learning value KG read in this routine. To do. That is, in this embodiment, the target injection time τ is the air-fuel ratio feedback correction coefficient FAF and the air-fuel ratio learning value KG with respect to the basic injection time τBASE.
It is calculated by multiplying together.

Next, at step 206, based on the detection signal from the crank angle sensor 28 and the like, it waits until the injection timing is reached. When the current injection timing has come, in step 207, the fuel injection is executed for the target injection time τ calculated in this routine, and the subsequent processing is temporarily terminated.

As described above, in the "air-fuel ratio control main routine", the air-fuel ratio feedback correction coefficient FAF and the air-fuel ratio learning value K with respect to the basic injection time τBASE.
The target injection time τ is calculated by multiplying G together, and the fuel injection is executed based on that value.

As described above, in this embodiment, in the air-fuel ratio control, the value obtained by multiplying the basic injection time τBASE by the air-fuel ratio feedback correction coefficient FAF and the air-fuel ratio learning value KG is the target injection time τ. Is set as. Here, the air-fuel ratio learning value KG is updated when various learning conditions are met and stored in the backup RAM 45.

Then, when the power supply from the battery 16 to the ECU 41 is interrupted, based on the total traveling distance TD,
The air-fuel ratio initial learning value KG1 is calculated, and that value is adopted as the initial air-fuel ratio learning value KG. Since the air-fuel ratio learning value KG adopted here corresponds to the degree of change over time of the engine 1, it becomes close to the value immediately before the power supply from the battery 16 is interrupted.

That is, for example, when the engine 1 is used for a long period of time, the air-fuel ratio learning value KG immediately before the power supply from the battery 16 is interrupted should be a relatively high value. In this embodiment, as shown by the solid line in FIG. 7, the relatively high value is adopted as the initial air-fuel ratio learning value KG. Therefore, the engine speed NE is smoothly increased at the same time when the engine 1 is started, and a stable operating state can be obtained. On the other hand, in the conventional technique, as shown by the broken line in the figure, the air-fuel ratio learning value KG is set to a relatively low value (for example, KG = “1”) that does not hinder various controls. Therefore, when the engine 1 has been used for a long period of time, it is understood that the engine rotation speed NE is unlikely to increase due to valve deposits and the like. In order to compensate for the problem, the engine speed NE is increased by setting the air-fuel ratio feedback correction coefficient FAF to a large value after a considerable amount of time has elapsed. As a result, the increase in the engine rotation speed NE is delayed, and the operating state becomes unstable until the engine rotation speed NE completely increases.

As is apparent from the above, according to this embodiment, even before the conditions for updating the air-fuel ratio learning value KG are met, the operating condition of the engine 1 is just before the power supply is interrupted. Since a state close to the state is secured, a relatively stable operating state can be secured. Further, if the update conditions are aligned, the air-fuel ratio learning value KG is restored to the learning value immediately before the power supply is interrupted in a relatively short time, and a more stable operating state can be secured promptly.

Further, when the power supply from the battery 16 is interrupted and the engine 1 is restarted, the air-fuel ratio learning value KG up to that time is erased. However, in this embodiment, paying attention to the fact that only the data of the total travel distance TD is mechanically stored, and this total travel distance TD is used to represent the degree of change over time of the engine 1.
The air-fuel ratio initial learning value KG1 is calculated based on that value. Therefore, the air-fuel ratio initial learning value KG1 can be brought close to the air-fuel ratio learning value KG immediately before the power supply from the battery 16 is interrupted.

The present invention is not limited to the above-described embodiment, but may be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the above embodiment, the air-fuel ratio learning value KG is adopted as the learning value for performing the air-fuel ratio control. However, the concept of the present invention may also be applied to, for example, idle speed control (ISC) or knock. It may be applied to learning value control of a control system (KCS).

(2) In the above embodiment, the trip meter 3
Although the digital switch type distance transmitting means is provided on the back side of the display surface of 0, the total traveling distance TD may be read by a so-called panel checker.

(3) In the above embodiment, the total traveling distance TD
In the map in which the air-fuel ratio initial learning value KG1 is set to, the air-fuel ratio initial learning value KG1 is set to linearly increase as the total traveling distance TD increases, but it is not necessarily set in this way. That is, for example, the air-fuel ratio initial learning value KG1 may be set to increase in a curve, or the air-fuel ratio initial learning value KG1 may not be further increased when the total traveling distance TD reaches a constant value. .

(4) In the above embodiment, when calculating the target injection time τ, the air-fuel ratio feedback correction coefficient FAF and the air-fuel ratio learning value KG with respect to the basic injection time τBASE.
However, the calculation method of the target injection time τ is not necessarily limited to the above. Therefore, in addition to this, for example, the target injection time τ may be calculated in consideration of the element of the power supply voltage of the battery 16.

[0050]

As described above in detail, according to the present invention, the learning value updated according to the deviation between the basic operating state of the internal combustion engine and the current operating state and stored in the storage means fed from the battery. In the control device of the above, when it is determined that the power supply from the battery to the storage unit is interrupted, and even after the internal combustion engine is started until the learning value update condition is satisfied, Since the initial value of the learning value is calculated based on the detection result of the temporal change degree detecting means that indirectly detects the degree of change, it is possible to ensure a relatively stable operating state. .

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a learning value control device in one embodiment embodying the present invention.

FIG. 3 is a block diagram showing an electrical configuration of an ECU in one embodiment.

FIG. 4 is a flowchart illustrating a processing operation of an “initial learning value calculation routine” executed by the ECU in one embodiment.

FIG. 5 is a map showing a relationship between an air-fuel ratio initial learning value and a total traveled distance in one embodiment.

FIG. 6 is a flowchart illustrating a processing operation of an “air-fuel ratio control main routine” executed by the ECU in one embodiment.

FIG. 7 is a timing chart for explaining a relationship between an air-fuel ratio learning value, a feedback correction coefficient, and an engine rotation speed with respect to time in one embodiment, in comparison with a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as internal combustion engine, 16 ... Battery, 30
... Trip meter as a means for detecting change over time, 41 ...
EC constituting storage means, determination means, and initial value calculation means
U.

Claims (1)

[Claims] 1. A control device for a learning value, which is updated in accordance with a deviation between a predetermined basic operating state of an internal combustion engine and a current operating state of the internal combustion engine, and is stored in a storage means fed from a battery, A temporal change degree detecting unit that indirectly detects the degree of change over time of the internal combustion engine, a determining unit that determines whether power supply from the battery to the storage unit is interrupted, and a determining unit that determines whether the power supply from the battery is changed. When it is determined that the power supply to the storage means is interrupted, an initial value calculation means for calculating an initial value of the learning value based on the detection result of the temporal change detection means is provided when the internal combustion engine is started. A fuel injection control device for an internal combustion engine, comprising: