JP2875873B2 - Fuel injection control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention [Industrial Application Field] The present invention relates to a fuel injection control device that generates a fuel injection control signal and gives the signal to a fuel injection device provided in an engine. A fuel determined by determining a fuel supply amount from a basic fuel supply amount determined according to the oxygen concentration in the exhaust gas discharged from the engine and a corrected fuel supply amount determined by fuzzy inference from the engine speed and the like. The present invention relates to an injection control device.

[Prior Art] Conventionally, as a fuel injection control device of this type, as in the fuel injection control device 10 shown in FIG. 9, (i) a fuzzy set relating to the opening of the throttle valve and a change in the opening of the throttle valve. Fuzzy Set and Fuzzy Set for Engine Speed and Fuzzy Set for Air Supply to Engine Combustion Chamber and Fuzzy Set for Oxygen Concentration in Air Supply to Engine Combustion Chamber and Oxygen Concentration in Exhaust Gas Based on a first fuzzy rule established between a fuzzy set and a fuzzy set related to a basic fuel supply amount, a throttle valve opening detection sensor 101
Throttle valve opening detected by the throttle valve opening change detection sensor 102 and throttle valve opening change detected by the sensor 102 and the engine speed detection sensor
The engine speed detected by 103 and the amount of air supplied to the combustion chamber of the engine detected by the air supply amount detection sensor 104 and the air supplied to the combustion chamber of the engine detected by the oxygen concentration detection sensor 105 The basic fuel supply amount is obtained by fuzzy inference in the basic fuel supply amount inference device 201 in accordance with the oxygen concentration in the exhaust gas and the oxygen concentration in the exhaust gas detected by the exhaust gas oxygen concentration detection sensor 106, and (ii) throttle A fuzzy set concerning the valve opening, a fuzzy set concerning the change of the throttle valve opening, a fuzzy set concerning the engine speed, a fuzzy set concerning the temperature of the engine cooling water, and a fuzzy set concerning the increased fuel supply amount. Based on fuzzy rules, throttle valve opening detection sensor 101
The change in the opening of the throttle valve detected by the throttle valve and the throttle valve opening change detected by the sensor 102, the engine speed detected by the engine speed detection sensor 103, and the engine coolant temperature detected by the engine coolant temperature detection sensor 107 The increased fuel supply amount is obtained by fuzzy inference by the increased fuel supply amount inference device 202 in accordance with the temperature of the engine cooling water, and (iii) a fuzzy set relating to the temperature of the fuel supplied to the combustion chamber of the engine and the engine A fuel temperature detection sensor is provided based on a third fuzzy rule which is established between a fuzzy set relating to the temperature of the air supplied to the fuel chamber, a fuzzy set relating to the voltage fluctuation of the battery and a fuzzy set relating to the corrected fuel supply amount.
The temperature of the fuel supplied to the combustion chamber of the engine detected by 108 and the temperature of the air supplied to the fuel chamber of the engine detected by the air temperature detection sensor 109 and the voltage of the battery detected by the voltage fluctuation detection sensor 110 In accordance with the fluctuation, the corrected fuel supply amount inference device 203 obtains the corrected fuel supply amount by fuzzy inference, and (iv) the basic fuel supply amount and the increased fuel supply amount inference device obtained by the basic fuel supply amount inference device 201. The fuel supply amount is determined by the fuel supply amount determination device 204 from the increased fuel supply amount determined in 202 and the corrected fuel supply amount determined by the corrected fuel supply amount inference device 203, and then (v) the crank angle detection sensor 111 The fuel injection time is detected by the injection time detection sensor 301 from the crank angle detected by (vi), and (vi) the fuel supply amount determination device 20
The fuel supply amount obtained in (4) is converted by the conversion device 601 into a fuel injection time starting from the injection time detected by the injection time detection device 301, and (vii) a fuzzy set concerning the throttle valve opening and the throttle valve opening A throttle valve opening detection sensor 10 is provided based on a fourth fuzzy rule that is established between a fuzzy set relating to the change, a fuzzy set relating to the engine speed, and a fuzzy set relating to the supply or cutoff of fuel to the combustion chamber of the engine.
In accordance with the throttle valve opening detected by 1 and the throttle valve opening change detected by the throttle valve opening change detection sensor 102 and the engine speed detected by the engine speed detection sensor 103,
The fuel supply cutoff inference device 501 obtains fuel supply or cutoff to the combustion chamber of the engine by fuzzy inference and outputs it as a fuel supply cutoff signal, and (viii) the conversion device 601
The fuel injection control signal is generated by the fuel injection control signal generator 801 according to the fuel injection time converted in the above, and the fuel supply cutoff signal output from the fuel supply cutoff inference device 501 and the cylinder detection device detected by the cylinder detection sensor 112 A system has been proposed which is provided to a fuel injection device 701 provided in an engine according to the operating state of a cylinder determined by 401.

[Problems to be Solved] However, in the conventional fuel injection control device 10 , the basic fuel supply amount inferring device 201 uses the basic fuel supply amount obtained by fuzzy inference and the increased fuel supply amount inferring device 202 uses the increase obtained by fuzzy inference. Since the fuel supply amount is determined by the fuel supply amount determination device 204 from the fuel supply amount and the corrected fuel supply amount obtained by fuzzy inference by the corrected fuel supply amount inference device 203, (i) the fuel supply amount is determined. The fuzzy inference must be executed at three places, which leads to a complicated disadvantage, and furthermore, (ii) a fuzzy inference execution circuit becomes complicated, and (iii) a large amount of time is required for the fuzzy inference. As a result, (iv) downsizing or inexpensiveness cannot be achieved, and immediacy of fuel injection control cannot be ensured.

In order to eliminate these drawbacks, the present invention provides a correction fuel obtained by fuzzy inference from a basic fuel supply amount determined according to the oxygen concentration in the exhaust gas discharged from the engine and the engine speed. It is an object of the present invention to provide a fuel injection control device that determines a fuel supply amount from a supply amount.

(2) Configuration of the Invention [Means for Solving the Problems] The means for solving the problems provided by the present invention is as follows: "A fuel injection control device that generates a fuel injection control signal and gives the signal to a fuel injection device provided in the engine. (A) for determining a basic fuel supply amount to the combustion chamber of the engine according to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine detected by the exhaust gas oxygen concentration detection sensor (106). Basic fuel supply amount determination device (20
1) and (b) between a fuzzy set related to the engine speed, a fuzzy set related to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine, and a fuzzy set related to the corrected fuel supply to the combustion chamber of the engine. Based on the first fuzzy rule that is satisfied, the engine speed detection sensor (10
3) or the engine speed calculated from the crank angle detected by the crank angle detection sensor (111) by the engine speed calculation device (103A) and the exhaust gas detected by the exhaust gas oxygen concentration detection sensor (106). A corrected fuel supply amount inference device (203) for obtaining a corrected fuel supply amount by fuzzy inference according to the oxygen concentration in the gas; and (c) a basic fuel determined by the basic fuel supply amount determination device (201) Supply amount and corrected fuel supply amount inference device (203)
(D) a fuel supply amount determining device for determining the fuel supply amount to the combustion chamber of the engine in accordance with the corrected fuel supply amount obtained by (c), and (d) the crank angle detected by the crank angle detection sensor (111). Injection time detection device (301) for detecting the injection time of fuel into the combustion chamber of the engine from an angle
And (e) a conversion device for converting the fuel supply amount obtained by the fuel supply amount determination device (204) into a fuel injection time starting from the injection time detected by the injection time detection device (301) and outputting the converted fuel ( 601) and (f) an engine speed detection sensor (103) based on a second fuzzy rule established between a fuzzy set regarding engine speed and a fuzzy set regarding supply or cutoff of fuel to a combustion chamber of the engine. Supply or cut-off of fuel to the combustion chamber of the engine by fuzzy inference according to the engine speed calculated from the crank angle detected by the crank angle detection sensor (111) by the engine speed calculation device (103A) or detected by the engine speed calculation device (103A) (G) a fuel supply cut-off inference device for determining and outputting a fuel supply cut-off signal; A fuel injection control signal is generated in accordance with the fuel injection time output from the fuel supply cut-off inference device, and the fuel injection device disposed in the engine according to the fuel supply cut-off signal output from the fuel supply cut-off inference device. And a fuel injection control signal generating device (801) for providing the control signal to the fuel injection control device.

[Operation] The fuel injection control device according to the present invention generates the fuel injection control signal and supplies the fuel injection control signal to the fuel injection device provided in the engine, as specified in the above-mentioned [Solution Means] section. The control device, in particular, (a) determines a basic fuel supply amount to the engine combustion chamber according to the oxygen concentration in the exhaust gas discharged from the engine combustion chamber detected by the exhaust gas oxygen concentration detection sensor. (B) a fuzzy set related to the engine speed, a fuzzy set related to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine, and a corrected fuel supply rate to the combustion chamber of the engine. Based on the fuzzy rules established between the fuzzy set and the engine speed detection sensor or the engine speed calculation device To obtain the corrected fuel supply amount by fuzzy inference according to the engine speed calculated from the crank angle detected by the crank angle detection sensor and the oxygen concentration in the exhaust gas detected by the exhaust gas oxygen concentration detection sensor. Correction fuel supply amount inference device, and (c)
Fuel supply amount determination for determining the fuel supply amount to the combustion chamber of the engine according to the basic fuel supply amount determined by the basic fuel supply amount determination device and the corrected fuel supply amount determined by the corrected fuel supply amount inference device. Since it is equipped with a device, it has the effect of (i) simplifying fuzzy inference, and thus (ii) the effect of simplifying the execution circuit of fuzzy inference, and (iii) the effect of accelerating fuzzy inference. (Iv) To achieve miniaturization or inexpensiveness and to ensure the immediacy of fuel injection control.

Next, a preferred embodiment of a fuel injection control device according to the present invention will be described in detail with reference to the accompanying drawings.

However, the embodiments described below are described for facilitating or facilitating the understanding of the present invention, and are not described for limiting the present invention.

In other words, each element disclosed in the embodiments described below includes all design changes and equivalent replacements that fall within the spirit and scope of the present invention.

FIG. 1 is a circuit diagram showing a first embodiment of a fuel injection control device according to the present invention.

FIG. 2 is a graph for explaining the operation of the embodiment shown in FIG. 1. In particular, FIG. 2 shows an example of a conversion graph for determining the basic fuel supply amount from the air supply amount by the basic fuel supply amount determining device 201. Is shown.

3 (a) to 3 (d) are graphs for explaining the operation of the embodiment of FIG. 1, and are used particularly in fuzzy inference in the corrected fuel supply amount inference device 203 and the fuel supply cutoff inference device 501. 1 shows an example of a fuzzy set.

Figure 4 (a ₁₎ ~ (j) is a graph for explaining the operation of Figure 1 embodiment, particularly showing an example of fuzzy inference in the correction fuel supply quantity estimating apparatus 203.

Figure 5 (a ₁₎ ~ (e) is a graph for explaining the operation of Figure 1 embodiment, particularly the fuel supply cutoff inference apparatus
An example of fuzzy inference at 501 is shown.

FIG. 6 is a circuit diagram showing a second embodiment of the fuel injection control device according to the present invention.

FIG. 7 is a circuit diagram showing a third embodiment of the fuel injection control device according to the present invention.

FIG. 8 is a circuit diagram showing a fourth embodiment of the fuel injection control device according to the present invention.

(Configuration of First Embodiment) First, the configuration of a first embodiment of a fuel injection control device according to the present invention will be described in detail with reference to FIG.

In the following, for convenience, a case mainly applied to a gasoline engine will be described, but the fuel injection control device according to the present invention is not limited to this.
The present invention is applicable to various other engines such as a diesel engine. Incidentally, when the fuel injection control device according to the present invention is applied to, for example, a diesel engine, it is only necessary to appropriately remove unnecessary members and appropriately correct defective portions.

Reference numeral 10 denotes a fuel injection control device according to the present invention, which is provided for an engine (not shown), and the number of revolutions of the engine per unit time (referred to as "engine revolution number").
And an exhaust gas oxygen concentration detection sensor 106 for detecting the concentration of oxygen in the exhaust gas discharged from the combustion chamber of the engine.
And a crank angle detection sensor 111 for detecting the angle of the crank, and a piston provided at a predetermined position (for example, an appropriate position corresponding to the top dead center) of all cylinders included in the engine. A cylinder detection sensor 112 for detecting arrival at a predetermined position.
Incidentally, the cylinder detection sensor 112 may be provided in one of the plurality of cylinders.

The fuel injection control device 10 according to the present invention is also connected to the exhaust gas oxygen concentration detection sensor 106, and the oxygen concentration in the exhaust gas given from the exhaust gas oxygen concentration detection sensor 106 (“exhaust gas oxygen concentration”). ) Is provided with a basic fuel supply amount determination device 201 for determining the basic fuel supply amount from the detection result.

The fuel injection control device 10 according to the present invention further includes an engine speed detection sensor 103 and an exhaust gas oxygen concentration detection sensor 1.
06, a fuzzy set relating to the engine speed, a fuzzy set relating to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine, and a fuzzy set relating to the corrected fuel supply to the combustion chamber of the engine. Based on the first fuzzy rule, the engine speed detected by the engine speed detection sensor 103 and the exhaust gas exhausted from the combustion chamber of the engine detected by the exhaust gas oxygen concentration detection sensor 106 A corrected fuel supply amount inference device 203 for obtaining a corrected fuel supply amount by fuzzy inference according to the oxygen concentration is provided.

The fuel injection control device 10 according to the present invention further includes a basic fuel supply amount determination device 201 and a corrected fuel supply amount inference device 203.
The combustion of the engine is performed based on the determination result of the basic fuel supply amount given from the basic fuel supply amount determination device 201 and the inference result of the corrected fuel supply amount given from the corrected fuel supply amount inference device 203. A fuel supply amount determination device 204 for determining the fuel supply amount to be supplied to the chamber is provided.

In addition, the fuel injection control device 10 according to the present invention is connected to the crank angle detection sensor 111 and starts the fuel injection time given from the crank angle detection sensor 111 (that is, starts the fuel injection to the combustion chamber of the engine). Injection time detection device 301 for detecting the power injection time) and the cylinder detection sensor 112, which is connected to the cylinder detection sensor 112, detects the operating state of each cylinder, and creates a cylinder discrimination signal indicating the time during which fuel can be injected into each cylinder. Cylinder discriminating device 401 for output
And The cylinder determination device 401 determines (i) when the cylinder detection sensors 112 are arranged one-to-one with respect to all cylinders, the number of cylinders corresponding to the number of cylinders corresponding to the cylinder detection sensors 112 one-to-one. The signal is output as a cylinder discrimination signal as many as the number of cylinders output by appropriately processing the detection result of the cylinder detection sensor 112, and (ii) the cylinder detection sensor 112 If the number of cylinders is equal to the number of cylinders output by appropriately processing the detection result of the cylinder detection sensor 112, the number of the determination circuits is equal to the number of cylinders when the cylinders are provided only for the respective cylinders. Is output as a cylinder discrimination signal.

The fuel injection control device 10 according to the present invention additionally includes:
The engine speed sensor 103 is connected to the engine speed detection sensor 103, and based on a second fuzzy rule that is established between a fuzzy set related to the engine speed and a fuzzy set related to the supply or cutoff of fuel to the combustion chamber of the engine, the engine speed A fuel supply cutoff inference device for obtaining fuel supply or cutoff (that is, whether or not fuel supply should be cut off) by fuzzy inference according to the engine speed detected by the detection sensor 103 and outputting it as a fuel supply cutoff signal It has a 501.

The fuel injection control device 10 according to the present invention is also connected to the fuel supply amount determination device 204 and the injection time detection device 301, and shows the result of determining the fuel supply amount given from the fuel supply amount determination device 204. Voltage signal is used to detect fuel injection time 30
Conversion device for converting and outputting a time signal starting at a given fuel injection time from 1 or a fuel injection time signal
601, a cylinder discriminating device 401, a fuel supply cutoff inference device 501, and a fuel injection cutoff signal supplied from the fuel supply cutoff inference device 501 which are connected to the conversion device 601 and receive the fuel injection time signal given from the conversion device 601. And a fuel injection control signal generation device 801 for passing the fuel injection control signal as a fuel injection control signal to the fuel injection device 701 in accordance with the cylinder determination signal provided from the cylinder determination device 401.

(Operation of First Embodiment) Further, the operation of the first embodiment of the fuel injection control device according to the present invention will be described with reference to FIGS. ₁ to 5 (a1) to (e). This will be described in detail.

Determination of Basic Fuel Supply Amount The basic fuel supply amount is determined by the basic fuel supply amount determination device 201 as follows.

That is, the basic fuel supply amount determination device 201 sets the basic amount of fuel to be supplied to the engine according to the detection result of the oxygen concentration in the exhaust gas given from the exhaust gas oxygen concentration detection sensor 106 as the basic fuel supply amount. decide.

The basic fuel supply amount is created in advance based on, for example, a correlation existing between the oxygen concentration in the exhaust gas and the fuel supply amount when the engine is operated under no load, and stored in the basic fuel supply amount determining device 201. It is determined by the converted graph (see FIG. 2). For example, when the conversion graph is shown in FIG. 2 and the oxygen concentration in the exhaust gas is 13% as shown in Table 2, the basic fuel supply amount is determined to be 1.87 V.

Inference of Corrected Fuel Supply Amount The corrected fuel supply amount is obtained by fuzzy inference in the corrected fuel supply amount inference device 203 as follows.

That is, the corrected fuel supply amount inference device 203 includes a fuzzy set related to the engine speed (for example, a fuzzy set A in FIG. 3A) and a fuzzy set related to the exhaust gas oxygen concentration (for example, a fuzzy set B in FIG. 3B). ) and, on the basis of fuzzy set relating to the corrected fuel supply amount (e.g. FIG. 3 (c) fuzzy rule f ₁ ~f ₉ shown in fuzzy rule (for example, the first table holds between the fuzzy set C) of) Engine speed detection result given by engine speed detection sensor 103 and exhaust gas oxygen concentration detection sensor
A corrected fuel supply amount is obtained by fuzzy inference according to the exhaust gas oxygen concentration detection result given from 106. Below, inferred corrected fuel supply The fuzzy inference in the device 203 is shown in FIG.
The first one that is established among the fuzzy sets A to C shown in (c)
It is described as being performed on the basis of the fuzzy rule f ₁ ~f ₉ shown in Table. Accordingly, in the present invention, (i) the number of membership functions included in the fuzzy sets A to C may be increased or decreased, or the shape thereof may be changed, if desired, and (ii) the fuzzy rules f _{1 to} f ₉ may be changed. May be increased or decreased, or the content thereof may be changed.

The fuzzy inference in the corrected fuel supply amount inference device 203 is based on the detection result of the engine speed given from the engine speed sensor 103 and the exhaust gas oxygen concentration sensor 10
If the exhaust gas oxygen concentration detection result given from FIG. 6 is generalized and described, it will involve a great deal of complexity, so here, the engine speed detection result given by the engine speed detection sensor 103 and the exhaust gas The detection result of the exhaust gas oxygen concentration given from the gas oxygen concentration detection sensor 106 will be described exemplarily by giving a case where each is as shown in Table 2.

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _1, first (i) Based on Table 1, Figure 3 membership functions included in the fuzzy set A shown in (a) S _A third The membership function S _B included in the fuzzy set B shown in FIG. 9B is selected, and then (ii) the function values ▼ and の of the membership function S _A corresponding to the engine speed 2000 times / minute. function value ▲ ▼ and a fourth view of the membership function S _B corresponding to the exhaust gas oxygen concentration 13% (a ₁₎
Obtain as shown in (a ₂ ). 2000 engine revolutions /
Function value of membership function S _A corresponding to minute ▲ ▼
There FIG. 4 (a ₁₎ (a ₂₎ membership functions corresponding to the apparent as the exhaust gas oxygen concentration of 13% to S function value _B ▲
▼, the corrected fuel supply amount inference device 203
Is obtained by cutting the membership function NS _C belonging to the fuzzy set C shown in FIG. 3 (c) at the position of the height ▲ ▼, and forming a trapezoidal membership function NS as shown in FIG. 4 (a ₃ ). Create _C ^{* 1} .

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _2, first (i) Based on Table 1, Figure 3 membership functions included in the fuzzy set A shown in (a) S _A third elect a membership function M _B contained in the fuzzy set B shown in FIG. (b), then (ii) the function value of the membership function S _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ and function value ▲ ▼ and a fourth view of the membership function M _B corresponding to the exhaust gas oxygen concentration 13% (b ₁₎
Obtain as shown in (b ₂ ). 2000 engine revolutions /
Function value of membership function S _A corresponding to minute ▲ ▼
There FIG. 4 (b ₁₎ (b ₂₎ membership functions corresponding to the apparent as the exhaust gas oxygen concentration of 13% to M function value _B ▲
補正, the corrected fuel supply amount inference device 203
Is obtained by cutting the membership function ZR _C belonging to the fuzzy set C shown in FIG. 3 (c) at the position of the height ▲ ▼ and forming a trapezoidal membership function ZR as shown in FIG. 4 (b ₃ ). Create _C ^{* 2} .

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _3, first (i) Based on Table 1, Figure 3 membership functions included in the fuzzy set A shown in (a) S _A third elect a membership function L _B contained in the fuzzy set B shown in FIG. (b), then (ii) the function value of the membership function S _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ and function value ▲ ▼ and a fourth view of the membership function L _B corresponding to the exhaust gas oxygen concentration 13% (c ₁₎
Obtain as shown in (c ₂ ). 2000 engine revolutions /
Function value of membership function S _A corresponding to minute ▲ ▼
There FIG. 4 (c ₁₎ the function value of the membership function L _B corresponding to apparent as the exhaust gas oxygen concentration of 13 percent (c ₂₎ ▲
補正, the corrected fuel supply amount inference device 203
The membership function PS _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as shown (c ₃₎ which belongs to the fuzzy set C shown in FIG. 3 (c) 0)
Create a membership function PS _C ^{* 3} of

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _4, first (i) Based on Table 1, Figure 3 membership functions included in the fuzzy set A shown in (a) M _A and the third The membership function S _B included in the fuzzy set B shown in FIG. 13B is selected, and then (ii) the function values ▲ ▼ of the membership function M _A corresponding to the engine rotation speed of 2000 / min. function value ▲ ▼ and a fourth view of the membership function S _B corresponding to the exhaust gas oxygen concentration 13% (d ₁₎
Obtain as shown in (d ₂ ). 2000 engine revolutions /
Function value of membership function M _A corresponding to minute ▲ ▼
There FIG. 4 (d ₁₎ (d ₂₎ from the function value of the membership function S _B corresponding to the apparent as the exhaust gas oxygen concentration 13% ▲
▼, the corrected fuel supply amount inference device 203
The membership functions NM _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as shown (d ₃₎ which belongs to the fuzzy set C shown in FIG. 3 (c) 0)
To create a membership function NM _C ^{* 4.}

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _5, first (i) Based on Table 1, Figure 3 membership functions included in the fuzzy set A shown in (a) M _A and the third The membership function M _B included in the fuzzy set B shown in FIG. 13B is selected, and then (ii) the function values ▲ ▼ of the membership function M _A corresponding to the engine speed of 2000 / min. function value ▲ ▼ and a fourth view of the membership function M _B corresponding to the exhaust gas oxygen concentration 13% (e ₁₎
It is determined as shown in (e ₂ ). 2000 engine revolutions /
Function value of membership function M _A corresponding to minute ▲ ▼
There FIG. 4 (e ₁₎ function value of the membership function M _B corresponding to apparent as the exhaust gas oxygen concentration of 13 percent (e ₂₎ ▲
▼, the corrected fuel supply amount inference device 203
The membership functions ZR _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as shown (e ₃₎ which belongs to the fuzzy set C shown in FIG. 3 (c) 0)
To create a membership function ZR _C ^{* 5} of.

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _6, first (i) Based on Table 1, Figure 3 membership functions included in the fuzzy set A shown in (a) M _A and the third elect a membership function L _B contained in the fuzzy set B shown in FIG. (b), then (ii) the function value of the membership function M _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ and function value ▲ ▼ and a fourth view of the membership function L _B corresponding to the exhaust gas oxygen concentration 13% (f ₁₎
It is obtained as shown in (f ₂ ). 2000 engine revolutions /
Function value of membership function M _A corresponding to minute ▲ ▼
There FIG. 4 (f ₁₎ function value of the membership function L _B corresponding to apparent as the exhaust gas oxygen concentration of 13 percent (f ₂₎ ▲
Since it is the same as ▼, the corrected fuel supply amount inference device 203
The membership function PS _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as shown (f ₃₎ which belongs to the fuzzy set C shown in FIG. 3 (c) 0)
Create the membership function PS _C ^{* 6} of

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _7, first (i) Based on Table 1, the membership functions are included in the fuzzy set A shown in FIG. 3 (a) L _A third elect a membership function S _B contained in the fuzzy set B shown in FIG. (b), then (ii) the function value of the membership function L _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ and function value ▲ ▼ and a fourth view of the membership function S _B corresponding to the exhaust gas oxygen concentration 13% (g ₁₎
Determine as shown in (g ₂ ). 2000 engine revolutions /
Function value of the membership function L _A corresponding to the minute ▲ ▼
There FIG. 4 (g ₁₎ (g ₂₎ from the function value of the membership function S _B to clear as corresponding to the exhaust gas oxygen concentration 13% ▲
▼, the corrected fuel supply amount inference device 203
The membership functions NM _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as shown (g ₃₎ belonging to the fuzzy set C shown in FIG. 3 (c) 0)
To create a membership function NM _C ^{* 7.}

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _8, first (i) Based on Table 1, the membership functions are included in the fuzzy set A shown in FIG. 3 (a) L _A third elect a membership function M _B contained in the fuzzy set B shown in FIG. (b), then (ii) the function value of the membership function L _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ and function value ▲ ▼ and a fourth view of the membership function M _B corresponding to the exhaust gas oxygen concentration 13% (h ₁₎
Determined as shown in (h ₂ ). 2000 engine revolutions /
Function value of the membership function L _A corresponding to the minute ▲ ▼
There FIG. 4 (h ₁₎ function value of the membership function M _B corresponding to apparent as the exhaust gas oxygen concentration of 13 percent (h ₂₎ ▲
▼, the corrected fuel supply amount inference device 203
The membership functions NS _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as indicated (h ₃₎ which belongs to the fuzzy set C shown in FIG. 3 (c) 0)
Create the membership function NS _C ^{* 8} of

Correction fuel supply quantity estimating apparatus 203 relates to a fuzzy rule f _9, first (i) Based on Table 1, the membership functions are included in the fuzzy set A shown in FIG. 3 (a) L _A third elect a membership function L _B contained in the fuzzy set B shown in FIG. (b), then (ii) the function value of the membership function L _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ and function value ▲ ▼ and a fourth view of the membership function L _B corresponding to the exhaust gas oxygen concentration 13% (i ₁₎
It is obtained as shown in (i ₂ ). 2000 engine revolutions /
Function value of the membership function L _A corresponding to the minute ▲ ▼
There FIG. 4 (i ₁₎ (i ₂₎ membership functions corresponding to the exhaust gas oxygen concentration of 13% as is evident from the L function value _B ▲
Since it is the same as ▼, the corrected fuel supply amount inference device 203
The membership functions ZR _C height ▲ ▼ Figure 4 is cut at the position of the ladder shape (where height as shown (i ₃₎ that belongs to the fuzzy set C shown in FIG. 3 (c) 0)
To create a membership function ZR _C ^{* 9.}

Correction fuel supply quantity estimating apparatus 203, the membership function NS _C ^{* 1} created by the ^{_{above, ZR C * 2, PS C}} * 3, NM C * 4, ZR C
^{_{* 5, PS C * 6,}} NM C * 7, NS C * 8, ZR C * 9 for enclosed hatched area in calculating the center of gravity as shown in Figure 4 (j), the abscissa -0.87V Is inferred as the corrected fuel supply amount.

Determination of Fuel Supply Amount The fuel supply amount is determined by the fuel supply amount determination device 204 as follows.

That is, the fuel supply amount determining device 204 determines the basic fuel supply amount (1.87 V in this case) provided from the basic fuel supply amount determining device 201 and the corrected fuel supply amount (here, 1.87 V) provided from the corrected fuel supply amount inference device 203. Then, -0.87V) is added at an appropriate ratio according to the characteristics of the engine to determine the fuel supply amount.

Generation of a fuel injection time signal The fuel supply amount determined by the fuel supply amount determination device 204 is given to the conversion device 601, and the fuel injection time is detected in accordance with the crank angle given from the crank angle detection sensor 111. It is converted into a fuel injection time signal starting at the fuel injection time detected by the device 301.

The fuel injection time signal is, for example, a signal that rises at the fuel injection time detected by the fuel injection time detection device 301 and maintains a high level state for a time corresponding to the fuel supply amount determined by the fuel supply amount determination device 204. is there.

Inference of fuel supply interruption Fuel supply or interruption (that is, whether or not fuel supply should be interrupted) is determined by the fuel supply interruption inference device 501.
It is obtained by fuzzy inference as follows.

That is, the fuel supply cutoff inference device 501 includes a fuzzy set relating to the engine speed (for example, a fuzzy set A in FIG. 3 (a)) and a fuzzy set relating to the fuel supply cutoff (for example, a fuzzy set D in FIG. 3 (d)). based on the fuzzy rules established between (e.g. fuzzy rule g ₁ to g ₄ shown in table 3), an engine speed sensor 103
In accordance with the result of the detection of the engine speed given by the above, the supply or cutoff of the fuel to the combustion chamber of the engine is obtained by fuzzy inference. Below, fuel supply cutoff inference The fuzzy inference in the device 501 is shown in FIGS.
It is described as being performed on the basis of the fuzzy rule g ₁ to g ₄ shown in indicated fuzzy set A, in Table 3 that holds between D. Therefore, in the present invention, if desired, (i)
The number of membership functions included in the fuzzy sets A and D may be increased or decreased, or their shapes may be changed.
i) to increase or decrease the number of fuzzy rules g ₁ to g _4, or may change its contents.

The fuzzy inference in the fuel supply cutoff inference device 501 is as follows.
If the result of detection of the engine speed given by the engine speed detection sensor 103 is generalized and described, it involves a great deal of complexity. Results,
An example will be described with reference to the case shown in Table 2.

Fuel cut off inference device 501 relates to the fuzzy rules g _1, based on the first (i) Table 3 elected membership function L _A contained in the fuzzy set A shown in FIG. 3 (a), then (ii) determining as shown in function value of the membership function L _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ the FIG. 5 (a _1). Fuel supply cutoff inference device 50
1, membership function L function value of _A ▲ ▼ corresponds to the height corresponding to the engine rotation speed 2000 times / min ▲
Figure 3 at the position of ▼ membership Figure 5 by cutting the membership function F _D belonging to the fuzzy set D shown in (d) (a ₂₎ a ladder shape (0 height in this case) as shown in Create function F _D ^{* 1} .

Fuel cut off inference device 501 relates to the fuzzy rules g _2, based on the first (i) Table 3 elected membership functions S _A contained in the fuzzy set A shown in FIG. 3 (a), Next, (ii) the function value ▼ of the membership function S _A corresponding to the engine speed of 2000 revolutions / minute is obtained as shown in FIG. 5 (b ₁ ). Fuel supply cutoff inference device 50
1 is the height ▲ corresponding to the function value ▲ ▼ of the membership function S _A corresponding to the engine speed 2000 times / minute.
▼ Figure 3 at the position of (d) to create a membership function N _D ^{* 2} of ladder shape as shown in FIG. 5 was cut membership functions N _D belonging to fuzzy set D (b ₂₎ shown I do.

The fuel supply cutoff inference device 501 selects a membership function M _A included in the fuzzy set A shown in FIG. 3A based on (i) Table _{3 with} respect to the fuzzy rule g3, then (ii) determining as shown in function value of the membership function M _a corresponding to the engine rotational speed 2000 rev / min ▲ ▼ the FIG. 5 (c _1). Fuel supply cutoff inference device 50
1 is the height ▲ corresponding to the function value ▲ ▼ of the membership function M _A corresponding to the engine speed 2000 times / minute.
▼ Membership of FIG. 3 in the position of Figure 5 to cut the membership function F _D belonging to the fuzzy set D shown in (d) (c ₃₎ ladder shape as shown in (here height 0) Create function F _D ^{* 3} .

Fuel cut off inference device 501 relates to the fuzzy rules g _4, based on the first (i) Table 3 elected membership function Z _A contained in the fuzzy set A shown in FIG. 3 (a), Next, (ii) the function value ▼ of the membership function Z _A corresponding to the engine speed of 2000 revolutions / minute is obtained as shown in FIG. 5 (d ₁ ). Fuel supply cutoff inference device 50
1 is the height ▲ corresponding to the function value ▲ ▼ of the membership function Z _A corresponding to the engine speed 2000 times / minute.
▼ Figure 3 at the position of (d) to create a membership function N _D ^{* 4} of ladder shape as shown in FIG. 5 was cut membership functions N _D belonging to fuzzy set D (d ₂₎ indicated I do.

Fuel cut off inference device 501 shown in FIG. 5 (e) for the membership functions _{^{F D * 1, N D *}} 2, F D * 3, N D * enclosed hatched area ⁴ created by the above The center of gravity is calculated as described above, the abscissa -2.61 V is obtained and compared with a predetermined value (for example, 0), and fuel is supplied or cut off according to the comparison result (here, since the comparison result is smaller than the predetermined value, Supply).

The fuel supply cutoff inference device 501 outputs an inference result as a fuel supply cutoff signal. The fuel supply cutoff signal is, for example, a signal that is in a high level state when the inference result is to supply the fuel and is in a low level state when the fuel is to be cut off.

Generation of Cylinder Discrimination Signal Cylinder discrimination device 401 discriminates the time during which fuel can be injected into each cylinder by processing the detection result given from cylinder detection sensor 112, and outputs it as a cylinder discrimination signal.

The cylinder discrimination signal is, for example, a signal that is set to a high level during the fuel injection possible time, and is generated for each cylinder.

Generation of fuel injection control signal The fuel injection time signal converted by the converter 601 is given to the fuel injection control signal generator 801, and the fuel supply cutoff signal given from the fuel supply cutoff inference device 501 is used to cut off the fuel. Is provided to the fuel injection device 701 as a fuel injection control signal for each cylinder according to the cylinder determination signal generated by the cylinder determination device 401, unless otherwise indicated. The fuel injection device 701 is a combustion chamber (and thus a cylinder) of the engine.
On the other hand, fuel is injected in an amount corresponding to the fuel supply amount obtained by the fuel supply amount determination device 204, and thus the fuel injection time signal.

On the other hand, when the fuel supply cutoff signal given from the fuel supply cutoff inference device 501 indicates that the fuel is cut off, the fuel injection time signal is sent from the fuel injection control signal generator 801 as the fuel injection control signal. Not given to 701.

Second Embodiment In addition, a configuration and an operation of a second embodiment of the fuel control injection device according to the present invention will be described in detail with reference to FIG.

In the second embodiment, the engine speed detection sensor 103 is replaced with an engine speed calculation device 103A, and the input end of the engine speed calculation device 103A is connected to a crank angle detection sensor 11A.
1 and is substantially the same as the first embodiment except that the engine speed is calculated from the detection result of the crank angle given from the crank angle detection sensor 111. It has a configuration.

In other words, the second embodiment has substantially the same operation and effect as the first embodiment, except that the number of sensors provided for the engine can be reduced.

Therefore, for simplicity of description, elements corresponding to those included in the first embodiment are denoted by the same reference numerals as in the first embodiment, and other detailed descriptions are given here. Is omitted.

Third Embodiment In addition, the configuration and operation of a third embodiment of the fuel control injection device according to the present invention will be described in detail with reference to FIG.

In the third embodiment, the cylinder detection sensor 112 is eliminated, and the input end of the cylinder discriminating device 401 is connected to the crank angle detection sensor 1.
11 is substantially the same as that of the first embodiment except that the operation state of the cylinder is determined from the detection result of the crank angle given from the crank angle detection sensor 111. It has the configuration of

In other words, the third embodiment has substantially the same operation and effect as the first embodiment, except that the number of sensors provided for the engine can be reduced.

Therefore, for simplicity of description, elements corresponding to those included in the first embodiment are denoted by the same reference numerals as in the first embodiment, and other detailed descriptions are given here. Is omitted.

Fourth Embodiment In addition, the configuration and operation of a fourth embodiment of the fuel control injection device according to the present invention will be described in detail with reference to FIG.

In the fourth embodiment, the cylinder detection sensor 102 is eliminated, and the input end of the cylinder discriminating device 401 is connected to the crank angle detection sensor 1.
11 is substantially the same as that of the second embodiment except that the operating state of the cylinder is determined from the detection result of the crank angle given from the crank angle detection sensor 111. It has the configuration of

In other words, the fourth embodiment has substantially the same operation and effect as the second embodiment, except that the number of sensors provided for the engine can be reduced.

Therefore, for simplicity of description, elements corresponding to those included in the second embodiment are given the same reference numerals as in the second embodiment, and other detailed descriptions are given here. Is omitted.

(Modification) In the above description, only the case where the cylinder discriminating device 401 is connected to the fuel injection control signal generating device 801 has been described. However, the present invention is not limited to this. A case where the fuel injection device is directly connected to the fuel injection control signal and the fuel is injected into the fuel injection device in response to the cylinder discrimination signal when the fuel injection control signal is given is also included.

Also, in the above description, the fuzzy inference is performed by cutting the top of the membership function to obtain the center of gravity, but the present invention is not limited to this, and may be performed in other well-known manners (for example, member It also subsumes the case where fuzzy inference is performed (by changing the height of the ship function to find the center of gravity). In other words, the present invention does not limit fuzzy inference to a certain one.

(3) Effects of the Invention As is apparent from the above description, the fuel control injection device according to the present invention is a fuel injection control device that generates a fuel injection control signal and gives the signal to a fuel injection device provided in an engine. In particular, (a) a basic fuel supply for determining a basic fuel supply amount to the combustion chamber of the engine according to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine detected by the exhaust gas oxygen concentration detection sensor. An amount determination device, and (b) a fuzzy set relating to the engine speed, a fuzzy set relating to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine, and a fuzzy set relating to the corrected fuel supply to the combustion chamber of the engine. Based on the fuzzy rule that holds, the engine speed is detected by the engine speed sensor or the crank speed is calculated by the engine speed calculator. According to the engine speed calculated from the crank angle detected by the angle detection sensor and the oxygen concentration in the exhaust gas detected by the exhaust gas oxygen concentration detection sensor,
A corrected fuel supply amount inference device for obtaining a corrected fuel supply amount by fuzzy inference; and (c) a corrected fuel supply amount determined by the basic fuel supply amount determined by the basic fuel supply amount determination device and the corrected fuel supply amount inference device. A fuel supply amount determination device for determining the fuel supply amount to the combustion chamber of the engine in accordance with the amount of the fuel supply, has the effect of (i) fuzzy inference being simplified, and (ii) fuzzy inference And (iii) have the effect of speeding up fuzzy inference, and consequently (iv) achieve the effect of achieving miniaturization or inexpensiveness and ensuring the immediacy of fuel injection control. Have.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a fuel injection control device according to the present invention, FIG. 2 is a graph for explaining the operation of the FIG. 1 embodiment, and FIG. ~ (d) graph for explaining the first FIG embodiment, FIG. 4 (a ₁₎ ~
(J) is a graph for explaining the first FIG embodiment, FIG. 5 (a ₁₎ ~ (e) are graphs for explaining the first FIG embodiment, the fuel injection according to Figure 6 the present invention FIG. 7 is a circuit diagram showing a second embodiment of the control device, FIG. 7 is a circuit diagram showing a third embodiment of the fuel injection control device according to the present invention, and FIG. 8 is a fuel injection device according to the present invention. FIG. 9 is a circuit diagram showing a fourth embodiment of the control device, and FIG. 9 is a circuit diagram showing a conventional example. 10 Fuel injection control device 103 Engine speed detection sensor 103A Engine speed calculation device 106 Exhaust gas oxygen concentration detection sensor 111 Crank angle detection sensor 112 Cylinder detection sensor 201 Basic fuel Supply amount determination device 203 ... Corrected fuel supply amount inference device 204 ... Fuel supply amount determination device 301 ... Injection time detection device 401 ... Cylinder determination device 501 ... Fuel supply cutoff inference device 601 ... Conversion device 701 ... Fuel injection device 801 ... Fuel injection control signal generator

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 41/00-45/00 G05B 13/02

Claims (1)

(57) [Claims] A fuel injection control device for generating a fuel injection control signal and applying the signal to a fuel injection device provided in the engine, comprising: (a) a combustion chamber of the engine detected by an exhaust gas oxygen concentration detection sensor (106); Fuel supply amount determining device (20) for determining the basic fuel supply amount to the combustion chamber of the engine according to the oxygen concentration in the exhaust gas discharged from the engine
1) and (b) between a fuzzy set related to the engine speed, a fuzzy set related to the oxygen concentration in the exhaust gas discharged from the combustion chamber of the engine, and a fuzzy set related to the corrected fuel supply to the combustion chamber of the engine. Based on the first fuzzy rule that is satisfied, the engine speed detection sensor (10
3) or the engine speed calculated from the crank angle detected by the crank angle detection sensor (111) by the engine speed calculation device (103A) and the exhaust gas detected by the exhaust gas oxygen concentration detection sensor (106). A corrected fuel supply amount inference device (203) for obtaining a corrected fuel supply amount by fuzzy inference according to the oxygen concentration in the gas; and (c) a basic fuel determined by the basic fuel supply amount determination device (201) Supply amount and corrected fuel supply amount inference device (203)
(D) a fuel supply amount determining device for determining the fuel supply amount to the combustion chamber of the engine in accordance with the corrected fuel supply amount obtained by (c), and (d) the crank angle detected by the crank angle detection sensor (111). Injection time detection device (301) for detecting the injection time of fuel into the combustion chamber of the engine from an angle
And (e) a conversion device for converting the fuel supply amount obtained by the fuel supply amount determination device (204) into a fuel injection time starting from the injection time detected by the injection time detection device (301) and outputting the converted fuel injection time ( 601) and (f) an engine speed detection sensor (103) based on a second fuzzy rule established between a fuzzy set regarding engine speed and a fuzzy set regarding supply or cutoff of fuel to a combustion chamber of the engine. Supply or cut-off of fuel to the combustion chamber of the engine by fuzzy inference according to the engine speed calculated from the crank angle detected by the crank angle detection sensor (111) by the engine speed calculation device (103A) or detected by the engine speed calculation device (103A) (G) a fuel supply cut-off inference device for determining and outputting a fuel supply cut-off signal; A fuel injection control signal is generated in accordance with the fuel injection time output from the fuel supply cut-off inference device, and the fuel injection device disposed in the engine according to the fuel supply cut-off signal output from the fuel supply cut-off inference device. And a fuel injection control signal generating device (801) for providing the control signal to the fuel injection control device.