JPH06146995A - Engine controller and control thereof - Google Patents

Abstract

PURPOSE:To achieve control of fuel injection and ignition timing which are not affected by noise by determining filling efficiency in the amount of inlet air based on the difference in the in-cylinder pressure, for which variation in two or more in-cylinder pressure values in compression stroke, is smoothed. CONSTITUTION:The pressure in a combustion chamber is detected by an in- cylinder pressure sensor 8 provided on a cylinder head 1a, and is output to an ECU (electronic control unit) 14. The in-cylinder pressure is smoothed in terms of variation in the pressure during a compression stroke for a fixed period of time by the ECU 14 based on a polytropic variation expression by using two or more in-cylinder pressure values measured and stored at crank angle timing which is specified in the compression stroke. The difference in the in-cylinder pressure for a specific period of time after smoothing, with which noise is removed, is determined, while the engine speed is measured based on the output signal from a crank angle sensor 11. Filling efficiency is calculated by means of filling efficiency calculation expression which is preliminarily determined by experience based on the difference in the in-cylinder pressure and the engine speed thus determined. Fuel injection and ignition timing are controlled based on the results.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control apparatus and an engine control method for calculating and controlling a fuel injection timing, a fuel injection amount, and an ignition timing from the pressure of a combustion chamber (hereinafter referred to as cylinder pressure). is there.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram of a conventional engine control device disclosed in, for example, Japanese Unexamined Patent Publication No. 1-253543. In FIG. 8, reference numeral 61 denotes an engine body in which a cylinder head 61a is provided with an in-cylinder pressure sensor 62 and an in-cylinder temperature sensor 63 in each cylinder.
The detection unit of the in-cylinder temperature sensor 63 is exposed in the combustion chamber of the cylinder.

An injector 64 is arranged at an intake port 61b communicating with each cylinder of the engine body 61, and the intake port 61b is communicated with a throttle chamber 66 via an intake manifold 65.

An upstream side of the throttle chamber 66 is connected to an air cleaner 68 via an intake pipe 67.

A distributor 691 connected to a camshaft (not shown) of the engine body 61 is provided with a timing sensor (crank angle sensor) 610 for detecting a preset crank angle of each cylinder.

On the other hand, an air-fuel ratio sensor 611 is installed at the confluence portion of the intake manifold 69 communicating with the intake port 61c of the engine body 61. Incidentally, 612 is a catalytic converter, and 613 is a throttle valve.

A control unit (hereinafter referred to as an ECU) 614 is composed of a microcomputer including, for example, a CPU, a RAM, a ROM, and an input interface. The in-cylinder pressure sensor 62 and the cylinder are provided on the input side of the ECU 614. An internal temperature sensor 63, a timing sensor 610,
The air-fuel ratio sensor 611 is connected.

Further, the injector 64 is connected to the output side of the ECU 614 via a drive circuit 616. Reference numeral 615 is an ignition plug, which is installed on the cylinder head 61a. The ignition plug 61 is connected to the output side of the ECU 614 via a drive circuit 617.
5 is connected.

Next, the operation will be described. EC mentioned above
The calculation of the intake air amount G _a for each cylinder in U614 is performed by the following equation, for example.

G _a = (P × V) / (R × T)

Here, P is a predetermined crank angle (for example, BTDC 90 ° CA, hereinafter, the crank angle will be referred to as ° CA) determined in advance during the compression process of each cylinder based on the timing sensor 610, EC under it
It is the in-cylinder pressure measured in U614. V is the volume of the combustion chamber at this predetermined crank angle. R is the gas constant during the compression process, and T is the in-cylinder gas temperature measured by the in-cylinder temperature sensor 63.

On the other hand, according to Japanese Unexamined Patent Publication No. 59-212433, as shown in FIG. 9, if the cylinder pressure difference between the compression bottom dead center (BDC) and the compression top dead center 40 ° CA is ΔP, The amount of air filled into the engine G _a and the cylinder pressure difference ΔP are shown in FIG.
A linear relationship as shown in 0 is established. There is also a method of calculating the intake air amount from the in-cylinder pressure difference ΔP at two predetermined crank angles during the compression process based on this relationship.

Further, according to Japanese Patent Application Laid-Open No. 60-47836, a two-dimensional map table of the fuel injection time stored in advance in the ROM of the ECU with the in-cylinder pressure difference ΔP and the engine speed N as parameters is used. There is also a method of obtaining the fuel injection time.

The ECU 614 executes the above calculation of the air charge amount G _a of the engine. The fuel injection pulse width T _i is calculated by the following formula based on this air amount calculation result.

T _i = K × G _a × K _FB × K _e

Here, K is an air-fuel ratio constant, K _FB is an air-fuel ratio feedback correction amount, and K _e is a correction coefficient for correcting the fuel injection pulse width based on the in-cylinder temperature sensor and the cooling water temperature sensor. Then, a signal is sent from the ECU 614 to the drive circuit 616 based on the result of the fuel injection pulse width calculation, the injector 64 is driven, and the air-fuel ratio control is performed.

Further, according to Japanese Patent Laid-Open No. 59-103965, the absolute value of the cylinder pressure as shown in FIG. 9 is measured at 40 ° CA after bottom dead center, and the cylinder pressure value and the engine speed are used. For each operating state to be determined, the ignition timing is determined by the ECU 614 based on a predetermined two-dimensional map of the ignition timing, a signal is sent to the drive circuit 617, the ignition coil is driven, and the ignition timing is controlled.

In such an engine control device, according to JP-A-1-142228, the intake air amount is detected based on the in-cylinder pressure in the first half of the intake process or the changing speed thereof, and the intake process is performed based on the detection result. There is also a conventional example in which fuel injection is executed in the latter half.

[0019]

Since the conventional engine control device is configured as described above, the in-cylinder pressure value at a predetermined limited one or two crank angles during the compression process is used. As a result, when the influence of pressure pulsation, mechanical vibration, or electrical noise occurs on this predetermined limited one or two in-cylinder pressure signals, the in-cylinder pressure value corresponding to the true intake air amount is calculated. There is an essential problem that the detection accuracy cannot be detected, the accuracy of detecting the intake air amount decreases, the accuracy of air-fuel ratio control also decreases, and the accuracy of ignition timing control also decreases.

The invention of claim 1 is to solve the above-mentioned problems, and detects whether the amount of air filled in each cylinder is detected without a detection error, and whether the engine operating state is in a steady state. An object of the present invention is to provide an engine control device that can accurately control the fuel injection amount and the ignition timing regardless of the transient time, and can perform both the air-fuel ratio control and the ignition timing control with high precision.

According to the second aspect of the present invention, the amount of air filled in each cylinder is detected without a detection error, and the fuel injection amount and the ignition timing are set regardless of whether the engine operating state is steady or transient. It is an object of the present invention to provide an engine control method capable of accurately controlling the engine and accurately performing both the air-fuel ratio control and the ignition timing control.

[0022]

An engine control apparatus according to a first aspect of the invention is an in-cylinder pressure for measuring in-cylinder pressure at at least two or more crank timings in synchronization with a predetermined crank angle during a compression process. By using the measuring means, the noise removing means for removing noise contained in the pressure measurement value measured by the in-cylinder pressure measuring means, and the in-cylinder pressure value smoothed by removing the noise by the noise removing means. In-cylinder pressure calculation means for calculating the in-cylinder pressure difference within a predetermined crank period, filling efficiency calculation means for calculating the filling efficiency from this in-cylinder pressure difference, and fuel injection amount and ignition timing control based on this filling efficiency And a control means for controlling the operation.

According to another aspect of the engine control method of the present invention, a crank angle sensor generates a signal for generating a cylinder identification signal and a crank angle signal in synchronization with the rotation of a multi-cylinder engine, and the crank angle sensor detects the signal. Pressure measurement step for measuring the pressure in the combustion chamber of the multi-cylinder engine during the compression process in synchronization with the generated crank angle signal, and noise removal for removing noise in the pressure measurement value in the combustion chamber measured in this pressure measurement step Step, a charging efficiency calculation step for calculating the charging efficiency based on the combustion chamber pressure value calculated in the noise removal step, and a fuel supply amount and ignition timing of the multi-cylinder engine based on the obtained charging efficiency. And a control step for controlling.

[0024]

According to the engine control device and the control method therefor of the first and second aspects of the present invention, noise is removed by smoothing changes in at least two or more in-cylinder pressure values during a predetermined period during the compression process. It is calculated by the cylinder pressure difference due to the difference between the above values, the charging efficiency of the intake air amount is calculated based on this cylinder pressure difference, and the fuel injection amount and ignition timing are controlled based on this charging efficiency. It is possible to detect the charging efficiency, control the fuel injection and the ignition timing without being affected by the noise generated on the in-cylinder pressure.

[0025]

【Example】

Example 1. Embodiments of an engine control device and a control method thereof according to the inventions of claims 1 and 2 will be described below with reference to the drawings. FIG. 1 is a block diagram of the embodiment.
In FIG. 1, reference numeral 1 denotes an engine body, and a case of four cylinders is illustrated. A cylinder head 1a is provided with an in-cylinder pressure sensor 8 and an ignition plug 9 in each cylinder. The detector is in communication with the combustion chamber of the cylinder.

An injector 4 is installed in an intake port communicating with each cylinder of the engine body 1, and the intake port is communicated with a throttle body 17 via an intake manifold 5. A throttle valve 13 is installed in the throttle body 17, and a throttle opening sensor 15 for detecting the opening of the throttle valve 13 is attached to the throttle body 17.

An intake air temperature sensor 18 for measuring the intake air temperature is attached to the intake manifold 5. Further, a crank angle sensor 11 for detecting a preset crank angle of each cylinder is provided on a ring gear 12 that interlocks with a crank shaft (not shown) of the engine body 1. The crank angle sensor 11 outputs a reference position pulse for each reference position of the crank angle, and for each unit angle (for example, 1 °).
Output the unit angle.

On the other hand, an air-fuel ratio sensor 6 is installed in the exhaust manifold 2. In addition, a cylinder identification crank angle sensor 11a that interlocks with a cam shaft (not shown) in the cylinder head 1a is installed.

Reference numeral 14 denotes a control device as control means (hereinafter,
ECU), for example, a microcomputer including a CPU, a RAM, a ROM, and an input / output interface, an in-cylinder pressure signal input circuit that amplifies an output signal of the in-cylinder pressure sensor 8, and a drive output signal circuit that drives an injector and an ignition coil. It consists of

The ECU 14 includes an air-fuel ratio sensor 6, an in-cylinder pressure sensor 8, and crank angle sensors 11, 11.
a, a signal from the throttle opening sensor 15 is input, a predetermined calculation is performed, and a fuel injection signal and an ignition signal are sent to the injector 4, an ignition coil (not shown), and an ignition plug 9 through a drive circuit (not shown) built in the ECU. It is output to control the fuel injection amount and ignition timing.

FIG. 2 shows an in-cylinder pressure sensor 8 for detecting the pressure in the combustion chamber of this embodiment and its mounting condition. In FIG. 2, 21 is a cylinder block, 1 a is a cylinder head, 23 is a piston, 8 is a cylinder pressure sensor, and these are mounted on the cylinder block 21.

The pressure detecting portion 8a of the in-cylinder pressure sensor 8 is exposed to the pressure guiding portion 25 which communicates with the combustion chamber 24 of the engine, and outputs the in-cylinder pressure signal proportional to the pressure in the combustion chamber. The pressure detection unit 8a is connected to a pressure conversion element (not shown) to measure the pressure, for example, through silicone oil enclosed in a metal diaphragm.

This pressure conversion element has a high temperature (300 ° C.),
A semiconductor type sensor that can withstand high pressure (60 kg / cm ² ) is used, and a strain gauge formed by injecting impurities such as boron into single crystal silicon formed on silicon oxide is added via silicon oil. The pressure is converted into strain and measured. Alternatively, a piezoelectric element may be used as the in-cylinder pressure sensor.

Next, the calculation procedure of the ECU 14 will be described based on the flowcharts of FIGS. 3, 4 and 5.

FIG. 3 shows the main routine, which is shown in FIGS.
Shows an interrupt routine for synchronizing the crank angle. This Figure 3
A program with a built-in ROM in the ECU 14 is configured to process the crank angle synchronization interrupt routine shown in FIGS. 4 and 5 at fixed crank angle intervals during the processing of the main routine shown in FIG.

The flowchart of FIG. 3 shows the operation of the main routine of one embodiment of the present invention, and will be described later with reference to FIG.
The charging efficiency C _e is calculated based on the in-cylinder pressure difference ΔP between the in-cylinder pressures P ₁ and P ₂ smoothed by the interrupt routine of FIG. 5 to eliminate noise, and the fuel injection amount and ignition are calculated based on this result. Perform timing control.

FIG. 4 shows the interrupt routine shown in FIG.
Using the in-cylinder pressure value P (θ _i ) measured and stored at at least two or more crank angle timings determined in advance in one compression process, during the compression process (BTD) within a predetermined period.
C160-BTDC 40 ° CA) pressure change is controlled by combustion chamber volume V and index m Polytropic change PV ^m =
Based on the fact that n, the coefficients m and n are calculated and determined by the least squares method, and the operating procedure of the program for smoothing the in-cylinder pressure in the compression process as P = n · V ^−m is shown.

First, the operation of the main routine shown in FIG. 3 will be described. Here, the case of a single cylinder will be briefly described. However, for multiple cylinders, a process for identifying the cylinder based on the output signal of the crank angle sensor 11a is added, and each cylinder is similar to the case of the single cylinder. Process. In step 101, an interrupt routine 200, which will be described later, calculates and R
Noise-removed noise-removed in-cylinder pressures P ₁ and P ₂ are read from the RAM. In step 102, the in-cylinder pressure difference Δ is calculated from the in-cylinder pressures P ₁ and P _2.
P = P ₂ −P ₁ is calculated and stored. And step 10
At 3, the engine speed N is measured from the output signal of the crank angle sensor 11 and stored in the RAM. Then step 10
4, based on the cylinder pressure difference ΔP and the engine speed N, the charging efficiency C _e which is experimentally obtained in advance.
Is calculated by the filling efficiency calculation means in the ECU 14 using the following equation and stored in the RAM.

C _e = C _e0 × (a × ΔP / ΔP ₀ + b) × K _s

Here, the coefficients a and b are values which are experimentally obtained in advance based on the in-cylinder pressure difference ΔP and the engine speed N, for example, a = 1.109 and b = −0.108. It is a value. ΔP ₀ and C _e0 are the normalized central in-cylinder pressure difference ΔP and the normalized center filling efficiency at a predetermined operating point of the engine, which is predetermined with respect to the engine speed N.
Further, the coefficient K _s is a filling efficiency correction coefficient which is preset in the ROM as table data for the intake air temperature and the like.

In step 105, the charging efficiency C _e obtained in step 104 is used to calculate and store the injector valve opening pulse width T _p corresponding to the fuel injection amount using the following equation.

T _p = K _i × C _e × K _af × K _e + T _D

Here, K _i is a fuel discharge amount conversion coefficient of the injector for converting the charging efficiency C _e into a pulse width corresponding to the fuel injection amount at the theoretical air-fuel ratio, K _af is an air-fuel ratio correction coefficient, K _e
The air-fuel ratio feedback coefficient and other correction coefficient for correcting the air-fuel ratio based on the output of the air-fuel ratio sensor 6, T _D is the injector operation dead time correction value predetermined for the battery voltage.

At step 106, the ignition timing θ _SA is mapped from the ROM and calculated using the charging efficiency C _e and the engine speed N, and the routine proceeds to step 107. In step 107, the injector drive signal is output and set to the drive circuit based on the fuel injection pulse width T _p obtained in step 105, and the injector 4 is driven at a predetermined timing. Further, in step 108, ignition timing setting processing is performed based on the ignition timing θ _SA obtained as the result of the calculation in step 106, and an energization signal to the ignition coil is output.

Next, the operation of the cylinder pressure smoothing interrupt routine 200 will be described with reference to FIG. This interrupt routine 200 is provided in the ECU 14 so that the operation in the latter half of the compression process after the completion of the in-cylinder pressure detection routine 300 for crank angle synchronization, which will be described later with reference to FIG. 5, is executed at a predetermined timing. It is composed of a program stored in the ROM.

In step 201, variables i, A and B used in steps 203, 205 and 206 described later are reset to zero. RAM in step 202
In-cylinder pressure data P (θ _i ) at a predetermined crank angle θ _i stored in is read and the routine proceeds to step 203. In step 203, the in-cylinder pressure data P (θ _i )

A = A + log _e P (θ _i ).

And the integration calculation is carried out. Next step 20
4, the log of the engine combustion chamber volume V (θ _i ) stored in advance in the ROM at the crank angle θ _i corresponding to the detection timing of the in-cylinder pressure data P (θ _i ).
_Read eV (θ _i ).

In step 205, step 202
And P (θ _i ) and V (θ _i ) read in step 204
Using,

B = B + log _e P (θ _i ) × log _e V (θ _i )

The following arithmetic processing is performed. Then step 206
Then, the counter i for the number of integration processes is set to i = i + 1, and the process proceeds to step 207. In step 207, it is judged whether or not the processing number counter exceeds or is equal to a predetermined processing end counter value k, and "Y"
If it is determined to be "es", the process proceeds to step 208 and "N"
If it is determined to be "o", the process returns to step 202, and the integration process from step 202 to step 206 is repeated.

The values A and B calculated as described above are R
It is stored in AM. Then, these stored values A,
B is a polytropic change relational expression between the in-cylinder pressure P and the combustion chamber pressure V during the compression process based on the relationship shown in the following equation.

PV ^m = n ... (1)

It is used when the coefficient m and the constant n in are determined by the least square method. Step 2 of this procedure
From 08 to step 212 will be described. Above (1)
The formula is transformed to obtain the following formula.

[0055] _{log e P + mlog e V =} leg e n ··· (2)

The coefficient m and the constant n in the above equation (2) are determined by the least squares method using k pieces of data. That is, the coefficient m and the constant n are respectively

M = (C × A−D × B) / (k × C−D × D)

Log _e n = (k × B−D × A) / (k × C−D × D)

However, C and D are stored in the ROM in advance,
It is a constant given by

[0060]

[Equation 1]

[0061]

[Equation 2]

First, step 208 and step 209
Then, C and D given by the above equation are read from the ROM.
Then, in step 210, the value E = k × C−D × D previously stored in the ROM is read in the same manner as C and D. In step 211, the coefficient m of polytropic change is calculated by the following equation and stored in the RAM.

M = (C × A−D × B) / E

Next, the constant n of the polytropic change is calculated based on the following equation and stored in the RAM.

N = exp {(k × B−D × A) / E}

As described above, at least two or more crank timing detected k in-cylinder pressure detection values P are detected.
By obtaining the coefficient m and the constant n of the polytropic change in which the pressure is controlled, the smoothed pressure change value of the in-cylinder pressure P during the compression process can be calculated by P = nV ^−m .

Therefore, the routine proceeds to step 213, where the in-cylinder pressure P ₁ at a predetermined crank angle θ ₁ (BTDC 90 ° CA) during the compression process is

P ₁ = n × V ₁ ^-m

The cylinder pressure P after smoothing processing to RAM
Remember as ₁ . Next, the routine proceeds to step 214, where a predetermined crank angle θ ₂ during the compression process is set as in step 213.
Cylinder pressure P ₂ at (BTDC 40 ° CA)

P ₂ = n × V ₂ ^-m

Based on the above, it is calculated and stored in the RAM. Here, V ₁ and V ₂ are the combustion chamber volumes at the crank angles θ ₁ and θ ₂ .

By executing the above operation,
In-cylinder pressure detection value including noise P (θ ₁ ) to P (θ ₂ )
After smoothing the crank angle θ as a polytropic change curve as shown in FIG. 6, using P = n × V ^−m , the cylinder inside at the predetermined crank angles θ ₁ and θ ₂ during the compression process Obtain pressures P ₁ and P ₂ .

Next, the operation of the crank angle interrupt routine 300 will be described with reference to FIG. This crank angle interruption routine is performed at a predetermined crank angle θ ₀ (B
The program in the ROM is configured in advance so as to sequentially detect the in-cylinder pressure at predetermined crank angle intervals based on the crank angle detected by the crank angle sensor 11 based on the crank timing of (TDC 120 ° CA) and store it in the RAM.

In step 301, the crank angle is read from the crank angle sensor 11. Then step 302
, The predetermined crank angle θ _i previously stored in the ROM is compared and determined, and if the crank angle coincides with this crank angle θ _i
If it is determined to be s ", the routine proceeds to step 303. In step 303, the in-cylinder pressure P at this crank angle θ _i is detected and stored in RAM as P (θ _i ), and then this interrupt routine is terminated. Also, when it is determined to be “No” in step 302, this interrupt routine is ended.

Example 2. In the above embodiment, the polytropic change P during the compression process during the process of smoothing the in-cylinder pressure value.
= N · V ^−m , the polytropic index m is determined from the cylinder pressure measurement value P (θ _i ). This polytropic index m is m in the case of a gasoline engine during a predetermined compression process. = 1.32, so
Only the constant n may be determined based on the result obtained from the in-cylinder pressure measurement value P (i), and the same effect as that of the above-described embodiment is obtained.

The operation in this case will be described with reference to the flowchart of FIG. 7, steps 401 to 403 are step 3 in the flowchart of FIG.
The description is omitted because it is the same as 01 to step 303.

In step 404, the constant n of the polytropic change is calculated and calculated by the arithmetic mean from the k in-cylinder pressure detection values.

N = n + P (θ _i ) · V (θ _i ) ^-m

Based on the above, n is calculated and stored. Next, the routine proceeds to step 405, where the counter i is set to i = i + 1. The counter i and the constant n are reset to zero before executing this interrupt routine. In step 406,
It is determined whether the counter i is equal to or exceeds the predetermined value k. If “Yes” is determined in step 406, the process proceeds to step 407, where the average constant n _r of polytropic change is

N _r = n / k

Obtained from the above and stored in the RAM. According to the polytropic change relational expression P = n _r × V ^−m obtained as a result, in step 408 and step 409, the smoothed in-cylinder pressure P is set in the same manner as in step 213 and step 214 described above.
After calculating ₁ and P _2, they are stored in the RAM and used for the processing in the main routine 100.

[0082]

As described above, according to the first and second aspects of the present invention, the polytrope of the smoothed in-cylinder pressure given by the polytrope change from at least two or more in-cylinder pressure detection values during the compression process. The in-cylinder pressure difference ΔP during the predetermined period during the compression process is calculated based on the change formula, and the fuel injection amount and the fuel injection amount based on the filling efficiency calculated by the predetermined filling efficiency calculation formula for this ΔP value. Since the ignition timing is controlled, the charging efficiency can be accurately detected without being affected by noise, blowback, or abnormal pressure vibration on the cylinder pressure signal, and the engine operating condition is stable. It is possible to control the air-fuel ratio and ignition timing with high precision both during and during transient conditions, and to control the engine to the optimum air-fuel ratio that can constantly maintain high exhaust gas purification efficiency, and to prevent misfires and knocks during transient conditions. This has the effect of preventing the drivability from deteriorating.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an engine control device according to an embodiment of the present invention.

FIG. 2 is a configuration explanatory view showing an in-cylinder pressure sensor for detecting a pressure in a combustion chamber and an installation state thereof according to an embodiment of the present invention.

FIG. 3 is a flowchart of a main routine showing a flow of operations of the engine control device of the present invention.

FIG. 4 is a flowchart of a crank angle synchronization interrupt routine for explaining the first embodiment of the engine control device of the present invention.

FIG. 5 is a flowchart of a crank angle synchronization interrupt routine for explaining the first embodiment of the engine control device of the present invention.

FIG. 6 is a characteristic diagram of the relationship between the in-cylinder pressure detection value and the polytropic change of the present invention.

FIG. 7 is a flowchart of a crank angle synchronization interrupt routine for explaining the second embodiment of the engine control device of the present invention.

FIG. 8 is a diagram illustrating a configuration of a conventional engine control device.

FIG. 9 is a cylinder signal waveform diagram of a conventional engine control device.

FIG. 10 is a characteristic diagram of a relationship between a filling air amount and a cylinder pressure difference in a conventional engine control device.

[Explanation of symbols]

 8 In-cylinder pressure sensor (pressure measuring means) 11, 11a Crank angle sensor 14 ECU (noise removing means, charging efficiency calculating means)

[Procedure amendment]

[Submission date] May 19, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0075

[Correction method] Change

[Correction content]

Example 2. In the above embodiment, the polytropic change P during the compression process during the process of smoothing the in-cylinder pressure value.
= Was the polytropic exponent m when using n · V ^-m to be determined from the in-cylinder pressure measurements P (θ _i), in the period of the polytropic exponent m is a predetermined compression process, in the case of a gasoline engine, the engine Predetermined compression when specifications are determined
In the process period, m is given as a constant m = 1.32.
Therefore, only the constant n may be determined based on the result obtained from the in-cylinder pressure measurement value P (i), and the same effect as that of the above-described embodiment can be obtained.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

FIG. 3 is an engine control device and an engine control according to the present invention.
6 is a flowchart of a main routine showing a flow of operations of the control method .

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

FIG. 4 is an engine control device and engine control according to the present invention.
5 is a flowchart of a crank angle synchronization interrupt routine for explaining the first embodiment of the operation of the control device .

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

FIG. 5 is an engine control device and engine control according to the present invention.
5 is a flowchart of a crank angle synchronization interrupt routine for explaining the first embodiment of the operation of the control device .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

FIG. 7 is an engine control device and engine control according to the present invention.
6 is a flowchart of a crank angle synchronization interrupt routine for explaining a second embodiment of the operation of the control device .

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Front page continuation (72) Inventor Akira Izumi 840 Chiyoda-cho, Himeji-shi Himeji Works, Mitsubishi Electric Corporation (72) Inventor Norio Matsumoto 840 Chiyoda-cho, Himeji-shi Himeji Works (72) Invention Tatsuya Tsumura 840 Chiyoda-cho, Himeji City Mitsubishi Electric Corporation Himeji Works (72) Inventor Masakazu Sugai 6 Sadamoto-cho, Himeji City Mitsubishi Electric Engineer Ring Co., Ltd. Himeji Plant

Claims (2)

[Claims] 1. A crank angle sensor for generating a cylinder identification signal and a crank angle signal in synchronization with the rotation of a multi-cylinder engine, and a crank angle signal detected by the crank angle sensor in synchronization with the crank angle signal. Pressure measuring means for measuring the pressure in the combustion chamber of a multi-cylinder engine, noise removing means for removing noise in the pressure measurement value in the combustion chamber measured by the pressure measuring means, and pressure in the combustion chamber calculated by the noise removing means An engine control device comprising: a charging efficiency calculating means for calculating a charging efficiency based on a value; and controlling a fuel supply amount and an ignition timing of the multi-cylinder engine based on the obtained charging efficiency. 2. A signal generation stage by a crank angle sensor that generates a cylinder identification signal and a crank angle signal in synchronization with rotation of a multi-cylinder engine, and compression in synchronization with a crank angle signal detected by the crank angle sensor. A pressure measuring step for measuring the pressure in the combustion chamber of the multi-cylinder engine during the process, a noise removing step for removing noise of the pressure measurement value in the combustion chamber measured by the pressure measuring means, and a noise removing step for calculation. And a charging efficiency calculation step for calculating the charging efficiency based on the pressure value in the combustion chamber, and controlling the fuel supply amount and the ignition timing of the multi-cylinder engine based on the obtained charging efficiency. Control method.