JP2538626B2 - Control device for internal combustion engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine, and more particularly, to the number of man-hours and control accuracy of data input when performing various engine controls using a microcomputer. The present invention relates to an internal combustion engine control device that can be improved.

(Prior Art) Recently, various electronic controls have been performed in automobiles and the like with the development of electronics. For example, control related to engine combustion is one of them, and a microcomputer is widely applied to this. Has been done. In this case, the microcomputer internally has a map relating to combustion control of the engine, and the optimum value is stored in advance for this map value through experiments, etc. However, the greater the number of data, the better the control accuracy, Since the matching man-hour will increase, it is advantageous that the number of required data is small,
In this respect, a compromise has been made in an appropriate place.

There are various types of conventional control devices for internal combustion engines using this type of microcomputer, such as ignition timing control and fuel injection control. Among them, ignition timing control is a typical one. As a conventional technique for performing such ignition timing control, there is, for example, the one described in Japanese Patent Application Laid-Open No. 53-56429. In this device, the pressure in the combustion chamber (hereinafter referred to as cylinder pressure) is detected, and the crank angle at which the pressure becomes maximum (hereinafter referred to as cylinder pressure maximum timing) θ
Based on pmax is corrected controlling the ignition timing such that the θpmax coincides with a predetermined crank angle theta _M to maximize the torque generated by the engine.

The second one is described in JP-A-58-82074. In this device, the cylinder timing is detected, and the ignition timing is MBT controlled so that the θpmax comes to a predetermined position where the torque generated by the engine is maximized. At the same time, knocking is detected by passing a signal for detecting in-cylinder pressure through a signal processing circuit, and when the knocking level exceeds a predetermined value, ignition timing is retarded to control knocking with priority over MBT control. . Then, when knocking is controlled, the ignition timing is again MBT controlled so that the torque generated by the engine is maximized.

The microcomputer relating to the control of the two persons has a map for control inside, and as the map, for example, there is a basic table of ignition timing as shown in FIG. Then, the basic ignition timing is obtained from this basic table using the engine speed (engine speed) data and the intake air amount data as parameters. In this basic table, the ordinate and the abscissa are divided at equal intervals to create grid points for storing data. In detail, 8x8 =
It is divided into 64 to 16 × 16 = 256 grid points, and data is stored in each grid point.

(Problems to be Solved by the Invention) However, in such a conventional control apparatus for an internal combustion engine, a basic table is provided inside a microcomputer for ignition timing control, and the basic table is previously stored in the basic table. Since the data was stored in all data areas (corresponding to each grid point),
The process of actually realizing the operation state corresponding to each grid point and storing the optimum control data obtained from the operation result in the data area one by one, that is, the matching man-hours for matching the data are required. However, there has been a problem that the number of development man-hours increases, and eventually the cost of the engine increases.

In addition, since data is stored in all data areas, it is necessary to store data from the beginning even in an operating area where the frequency of actual use is extremely low depending on the engine, and useless matching occurs. Oops.

The above example is for ignition timing control, but when controlling the engine by the microcomputer, if the engine has a basic table, the same applies to other controls, such as fuel injection amount control and boost pressure control. There is a defect.

(Object of the invention) Therefore, an object of the present invention is to provide a control device for an internal combustion engine, which can reduce the number of matching steps of basic data and can improve the control accuracy of the engine and the control device. .

(Means for Solving Problems) In order to achieve the above object, the control device for an internal combustion engine according to the present invention refers to an operating state detecting means a for detecting the operating state of the engine and the operating state detecting means a separately according to the operating state of the engine. A data area b having a plurality of storage areas, basic data storage means c for storing basic data necessary for engine control in advance in a part of the data area, and data not stored depending on the operating state of the engine. When the empty area is referred to, the supplementary data is calculated based on the stored data of the area close to the empty area, and the supplementary data storage means d for storing the supplementary data in the empty area and the operating state of the engine are used. Updating means for updating the stored replenishment data based on the operating state of the engine when an area in which the replenishment data is already stored is referred to e, a control value calculating means f for calculating a control value for controlling the engine based on the stored data of the area referred to by the operating state of the engine, and an operation for operating a parameter related to the control of the engine based on the control value. And means g.

(Operation) In the present invention, since it is only necessary to match the minimum required number of basic data, the matching man-hours can be significantly reduced. Matching man-hours can be significantly reduced. Further, the lacking data is sequentially supplemented as supplementary data according to the operating state of the running engine, so that engine control is not hindered. Some data are used only under special operating conditions, but since basic data is not stored in such special areas, waste of having unused data is eliminated. The replenishment data is updated sequentially according to the actual operating state of the engine, and well follows the changes over time of the engine and the like, so that the control accuracy can be maintained good for a long period of time.

(Example) Hereinafter, the present invention will be described with reference to the drawings.

2 to 12 show a first control device for an internal combustion engine according to the present invention.
It is a figure showing an example, and this example is an example which controls especially ignition timing among controls of an internal-combustion engine.

First, the configuration will be described. In FIG. 2, reference numeral 1 denotes a sensor group, and the sensor group 1 is composed of a plurality of sensors that detect various parameters related to the operating state of the engine. That is, the sensor group 1 includes a crank angle sensor 2, an air flow meter 3, a throttle valve opening sensor 4, a cylinder discrimination sensor 5, a water temperature sensor 6, an accelerator sensor 7 and a pressure sensor 8.

The crank angle sensor 2 sets a predetermined position before the compression top dead center (TDC) of each cylinder at every explosion interval (crank angle 120 ° for a 6-cylinder engine, 180 ° for a 4-cylinder engine), for example, at a BTD 70 ° of [H] level. The reference position signal S ₁ that becomes a pulse is output, and the unit signal S ₂ that becomes a pulse of [H] level is output for each unit angle (for example, 2 °) of the crank angle. The engine speed Ne can be known by counting the signal S ₁ , and this processing is performed by the control unit 20 described later. The air flow meter 3 detects the intake air amount Qa to the engine, and the throttle valve opening sensor 4 detects the throttle valve opening Cv according to the load demand of the engine. Since the throttle valve opening sensor 4 is a sensor for detecting the load of the engine, it is not limited to the sensor for detecting the throttle valve opening Cv, and may be a sensor for detecting the intake pipe negative pressure, for example. Further, the cylinder discrimination sensor 5 discriminates a specific cylinder (for example, the first cylinder), and a cylinder discrimination signal is detected at a predetermined crank angle position (for example, BTDC80 ° of the first cylinder) before the compression top dead center of the specific cylinder. Output S ₅ . Therefore, this cylinder discrimination signal
S ₅ is output once every two rotations of the crankshaft. The water temperature sensor 6 detects the cooling water temperature in the engine, and the accelerator sensor 7 outputs an accelerator signal S ₇ according to the amount of depression of the accelerator pedal. The pressure sensor 8 is constituted by, for example, a piezoelectric element incorporated in a cylinder gasket between the cylinder head and the cylinder block, and a charge amplifier (not shown) that outputs a pressure signal S ₈ according to the pressure in the combustion chamber of the engine (cylinder pressure). It outputs to the control unit 20 and the knocking detection circuit 9 via.

The knocking detection circuit 9 is composed of a bandpass filter (BPF) 12 and a waveform shaping circuit 13, as shown in FIG. The band-pass filter 12 passes only the high frequency component S ₈ ′ (for example, 6 to 15 KHz) (see FIG. 4 (b)) which is particularly included when the knocking occurs from the pressure signal S ₈ (see FIG. 4 (a)). The waveform is output to the waveform shaping circuit 13, and the waveform shaping circuit 13 half-wave rectifies the high-frequency component S ₈ ′ and forms an envelope signal from the half-wave rectified signal (envelope detection). It is output to the control unit 20 as a knocking signal S ₉ as shown in. In this knocking detection circuit 9, the pressure signal S ₈ is smoothed to form a background level corresponding to the normal noise level of the engine, and the difference between the formed level and the maximum level of the envelope signal is knocked. It may be outputted as the signal S ₉ .

The sensor group 1 and the knocking detection circuit 9 constitute an operating state detection means 10 as a whole. The signals S _{1 to} S ₉ from the sensor group 1 are input to the control unit 20, and the control unit 20 includes the CPU 21, ROM 22 and RA.
The microcomputer is composed of an M23, an NVM (nonvolatile memory) 24, an input / output interface, a register, a counter, an A / D converter, an input / output control circuit 25 having a high-frequency cut filter, and the like. CPU21 is the input / output control circuit 25 according to the program written in ROM22.
The external data required by
While exchanging data with the M23, the processing value necessary for knock avoidance control, MBT control and control data setting supplement is arithmetically processed, and the processed data is output to the input / output control circuit 25 as necessary. To do. The input / output control circuit 25 receives signals from the sensor group 1 and the knocking detection circuit 9, and the input / output control circuit 25 outputs an ignition signal S ₁₀ . The ROM 22 stores a calculation program in the CPU 21, and also stores a predetermined number of data smaller than the entire data area in the basic ignition timing map in advance.
Performs temporary storage of data used for calculation and correction data and storage for data areas other than the prestored portion of the entire data area, and the NVM 24 retains the stored content even after the engine is stopped.

In the present embodiment, the above-mentioned CUP 21 is the correction data storage means, the updating means and the control value computing means, the ROM 22, RAM 23 and NVM (non-volatile memory) 24 are the data areas, and the ROM 22 is
Respectively constitute basic data storage means.

The ignition signal S ₁₀ is input to the ignition unit (operating means) 26, and the distributor 30 is connected to the ignition plugs 24a to 27.
f, ignition coil 28, power supply 29, distributor 30, and power transistor Q ₁ . The input / output control circuit 25 turns on the power transistor Q ₁ based on the ignition signal S _10.
N / OFF control is performed to generate a high voltage V _H on the secondary side of the ignition coil 28, and this high voltage V _H is distributed to the distributor 30.
Is distributed to the spark plugs 27a to 27f to ignite the mixture. The ignition timing control (ON / OFF control of the power transistor Q ₁ ) is performed by a value (advanced ignition timing) corresponding to an ignition timing determined in an advance value (ADV) register (not shown) provided inside the input / output control circuit 25. (Angle value) is set, the values of these registers are compared with the count value for counting the position signal S ₂ , and when they coincide, the power transistor Q ₁ is turned on or off.

Next, the operation will be described. First, the basic principle of this embodiment will be described. The basic principle of this embodiment is shown in the program of FIG. The prerequisites for executing this program are as follows.

First, a table of basic ignition timings for ignition timing control is prepared in advance in a predetermined area of the ROM 22, and optimum control values (basic data) obtained through experiments and the like are stored in each area of this table. This is a process corresponding to the above-mentioned data matching, and is performed at a predetermined stage before factory shipment. In this case, the predetermined area (memory area) of the ROM 22 does not correspond to the entire operation area as in the past, but only the area corresponding to the operation area corresponding to the idle condition and other minimum necessary conditions, for example. is there. As the base table, for example, FIG. 6 (b) are shown as the intake air amount Qa and (q ₁ to q _3), the engine speed N (n ₁ ~n ₃₎ and together the two-dimensional three stages The table A is used to store the data A ₁₁ ′ to A ₃₃ ′. Therefore, the memory area to be stored in the ROM 22 may be remarkably smaller than the conventional one, which leads to a reduction in matching man-hours. On the other hand, for areas where basic data is not stored, the memory areas of the RAM 23 and NVM 24 are used as learning tables, and subsequent supplementary data are sequentially stored in these areas. As a learning table, for example, as shown in FIG. 6A, the intake air amount (Q ₁ ~
Q ₈ ) and engine speed N (N _{1 to} N ₈ ) are divided into 8 levels, and a two-dimensional table is prepared. 8 × 8 = 64 ignition timing data (A _{11 to} A ₈₈ ) are prepared. The data is stored at each grid point. In this case, depending on the vehicle, there may be a driving area that is never used, so unlike the conventional case where basic data is prepared for all data areas from the beginning, the waste of matching can be eliminated. Also, the supplementary data is not calculated by interpolation of the basic data, but is calculated directly by a normal calculation format based on the actual operating state at that time and the average value of the data of the adjacent stored areas. Unlike that, the calculation time is short. The supplementary data thus obtained is stored in the corresponding data area as a substitute for the basic data.

Such data processing is performed by the program shown in FIG. Moving to FIG. 5, in P ₁ , the data area of the learning table corresponding to the current operating state is obtained using the intake air amount Qa and the engine speed N as parameters, and in P ₂ , the current data area is the first area for that area. It is determined whether it is a designation. Since still when the first area specifying data is not stored in the area, the optimum value of the ignition timing control is calculated based on the average value and the current combustion state of the data already stored area close by P ₃ , And stores this as supplementary data in the corresponding area. As a result, new data is replenished in the map area other than the basic data and the replenished data up to the previous time, and this replenishment data is immediately looked up for the next same area designation. On the other hand, if it is not the first area designation in P ₂ (after the second time), the optimum value of ignition timing control is calculated in P ₄ based on the current combustion state, and the stored data is updated to a new calculated value. . As a result, the latest data is always stored in the corresponding area following the changes over time of the engine and control device, which is also one of the great advantages of so-called learning control.

As can be seen from the above description, in the present embodiment, the supplementary data (learning value) is not taken in for each basic data stored in the preset area, but the supplementary data is used as a substitute for the basic data. The supplementary data obtained as described above is only updated according to the operating state.

Based on the above basic principle, in this embodiment, the ignition timing is controlled by the program shown in FIG. 7 and thereafter.

First, the combustion peak position θp required to perform MBT control
A subroutine program for obtaining max (which means the crank angle when the pressure in the combustion chamber becomes maximum. The same applies hereinafter) will be described with reference to FIG. The program shown in FIG. 7 is executed once every 2 ° CA in synchronization with the position signal S ₁ from the crank angle sensor 2.

First, the signal S ₈₀ obtained by cutting the high frequency component from the pressure signal S ₈ (indicating a signal corresponding to one cylinder) changing as shown in FIG. 8 (a) at P ₁₁ (see FIG. 8 (b)). It is determined whether or not it is the timing to start the A / D conversion, and if it is not the starting timing, the process immediately returns to the main routine shown in FIG. 9, and if it is the starting timing, it proceeds to P ₁₂ .

Here, the determination process of P ₁₁ is specifically performed as follows.

That is, the input / output control circuit 25 counts up the position signal S ₂ (2 ° signal) from the crank angle sensor 2 (see FIG. 8C) by the internal counter. The count value is reset each time the cylinder discrimination signal S _{5 from} is input. Then, the count value of this counter is read every time P ₁₁ is executed, and this read value corresponds to the crank angle range of the combustion process of each cylinder. Each section of the count value 0 to 60,60 to 120,120 to 180,180 to 240,240
~ 300,300 ~ 360 every xp, which is predetermined for θpmax detection
The first flag is set every time it matches + 60, x + 120, x + 180, x + 300. The first flag is set to be reset when θpmax described later is calculated, and the process proceeds to P ₁₂ only while the first flag is set. In P ₁₂ , the crank angle counter (soft counter) is incremented by [+1] (corresponding to 2 ° CA) in order to detect the crank angle based on x + 60n (n = 1,2,3 ...). Next, at P ₁₃ , the A / D converter of the input / output control circuit 25 is activated to A / D convert the pressure signal S ₈ at that time, and this A / D converted value is read after, for example, several tens of μsec.
At P ₁₄ , the difference value ΔP between the A / D converted value of the pressure signal S ₈ at the previous time and this time is calculated according to the following equation.

ΔP = AD1-ADφ ...... However, AD1: current A / D converted value ADfai: previous A / D conversion value (initially 0) is then compared with a reference value [Delta] P ₀ the difference value [Delta] P in P _15. The reference value ΔP ₀ is a value for determining that the signal level of the pressure signal S ₈ has become maximum, and is set to a predetermined value in advance. ΔP
When ≧ ΔP ₀ , it is judged that the signal level of the pressure signal S ₈ is not the maximum, and the current A / D conversion value AD 1 is changed to the old value ADφ at P _16.
To return. On the other hand, when ΔP <ΔP ₀ , it is determined that the signal level of the pressure signal S ₈ has become maximum, and at P ₁₇ , the combustion peak position θpmax is calculated from the count value α of the crank angle counter at that time and the above-mentioned x. Calculate according to.

θpmax = 2 (α + x) −80 ...... Incidentally, θpmax is represented by a crank angle with reference to the top dead center. Then, when the calculation of θpmax is completed, the above-mentioned first
The flag of is reset and the count value of the crank angle counter is reset. Next, at P ₁₈ , next A / D
For conversion, clear ADφ to zero and return.

By sequentially performing the above processing, the combustion peak position θ
pmax is calculated.

Next, the ignition timing control will be described with reference to the program shown in FIG. This program is executed once every time θpmax is calculated.

First, at P ₂₀ , the basic ignition timing ADVφ is looked up from the basic table as shown in FIG. 6 (b) which uses the engine speed N and the intake air amount Qa as parameters. This table map is given as a function of the engine speed N and the engine load (the intake air amount Qa is used as data, and may be data based on the negative pressure sensor output such as throttle opening and intake pipe internal pressure). Even in the low load region, even setting the condition of about MBT,
In the high load range, it is set according to the knocking level. However, this table map is created, for example, using the values matched with the median of these variations, without considering variations among engines, changes over time, changes in environment (changes in humidity, changes in fuel octane, etc.). By controlling, these fluctuation factors are absorbed and the accuracy as data is maintained.

Then, (as shown in FIG. 6 (a)) NVM24 the learning table by execution of the routine at P ₂₁ in the learning stored ignition timing correction amount learned value ADV1 (+, - data with sign)
Is looked up from the table map using N and Qa as parameters in the same manner as above. In P ₂₂ knock signal S ₉ from the knocking detection circuit 9 of FIG. 3 A / D conversion and incorporation as knocking level data KV, compares this KV with a predetermined slice level KVφ at P _23. KVφ is set to a value corresponding to, for example, a knock level that is extremely slight and has no problem in practical use. KV <determines that knocking when the KVφ has not occurred, the combination with MBT control of the ignition timing of the learning value ADV1 to come to a predetermined position where the combustion peak position θpmax is the maximum torque generated by the P ₂₄ Then, the ignition signal S ₁₀ is output at P ₂₅ .

On the other hand, when KV ≧ KVφ, it is determined that knock has occurred, and the knock timing knock control is performed so as to suppress the knock at P ₂₆ , and the process proceeds to P ₂₅ .

Next, regarding the MBT control performed in Step P ₂₄ ,
This will be described with reference to the program shown in the figure. In P _31, P _32, it is determined whether or not the engine is in excess operating condition.
Proceeds to P ₄₀ when it is determined that the engine P ₃₁ is accelerating, P ₄₅ when it is determined that the engine P ₃₂ is decelerating
Proceed to.

On the other hand, the process proceeds to P ₃₃ when it is determined that the engine P _31, P ₃₂ is in steady operation without excessive operating conditions. Specifically, these determinations are based on the accelerator signal from the accelerator sensor 7.
S ₇ is performed by comparing whether or not the amount of change per unit time of the data A / D converted by the A / D converter of the input / output control circuit 25 is larger than a predetermined value. Further, as another discriminant, for example, the intake air amount signal S ₃ or the load signal S ₄ can be used to perform the above determination, but since the response of the change in the accelerator pedal depression amount is the fastest, the accelerator signal S ₇ is used. It is desirable to use.

In P _33, the target crank angle range crank angle θpmax at cylinder pressure maximum determined in Figure 7 of the P ₁₇ is determined in advance .theta.M ₁
～ShitaM ₂ determines whether (θM ₁ <θM ₂₎ is within, .theta.M ₁ ≦
When θpamx ≤ θM ₂ , proceed to P ₄₁ , when θpmax <θM ₁ , proceed to P ₃₄ , and when θpamx> θM ₂ , proceed to P ₃₆ .
The purpose of this target crank angle range setting is to increase the stability of the MBT control. The range is such that the torque decreases by about 0.5% above and below θM with reference to the crank angle θM when the maximum torque is generated. Is θ M ₁ and the advance side is θ
It is set to M _2. However, since the generated torque characteristic of the engine changes according to the operating state of the engine, it is preferable to set θM ₁ and θM ₂ to be variable according to the operating state. In P ₃₄ , it is determined whether or not the state of θpmax <θM ₁ determined in P ₃₃ continues continuously for a predetermined number of times of n ignitions or more,
Crank angle θpmax when continuing n times or more
It is determined that There has been advanced, performs advance correction control at P _35. The process of P ₃₄ is the crank angle θ obtained in P ₁₇ of FIG.
Since pmax often becomes unstable due to changes in the operating state of the engine, this is done to reduce erroneous judgments due to this instability. In P ₃₅ the last of the feedback amount F
A value obtained by adding 1 ° CA to B (a value as a correction amount of the ignition timing based on θpmax and the initial value is zero) is used as the feedback amount FB of this time to perform the advance correction process.

On the other hand, when it is judged at P ₃₄ that it has not continued n times in a row, P ₃₅ is jumped to P ₃₈ .

In P ₃₆ , it is determined whether or not the state of θpmax> θM ₂ in P ₃₃ continues for a predetermined number of times m or more,
Crank angle θpmax when continuous more than m times
It determines that is retarded, performing retard correction control at P _37.
On the other hand, when the following m times proceeds to P ₃₈ to jump P _37.
Note the relationship between the "m" P ₃₆ "n" of the P ₃₄ is,? Pmax <theta
Since the torque decrease is larger in the case of M _{1 than in} the case of θpmax> θM ₂ , n <m is set. P ₃₇ value obtained by subtracting 1 ° CA from the previous feedback amount FB in performing retard correction processing to the current feedback amount FB.

At P ₃₈ , the basic ignition timing ADVφ obtained at P ₂₀ and P ₂₁ in Fig. 9
And feedback amount obtained by the learning value ADV1 and P _35, P ₃₇
The final ignition timing ADV is calculated by the following equation based on FB.

ADV = ADVφ + ADV1 + FB ...... Further, the process proceeds to P ₄₀ to interrupt the correction control of the ignition timing based on the crank angle θpmax when the engine at P ₃₁ is accelerating (during excessive operation). That is, during acceleration operation, θpmax
Becomes extremely unstable, the air-fuel ratio becomes lean due to the adhered wall surface of the injected fuel, and knocking occurs because the ignition timing is set to the advance side in the low load condition rather than in the high load condition. For example, the table for lookup of the delay amount table for avoiding knock during acceleration stored in advance in the ROM 22 with the engine speed data and the time change rate of the engine load data (the time differential value of the engine load data) is looked up. Then, after obtaining the retardation amount δ ₂ corresponding to the current acceleration operation state and performing a process of setting the obtained retardation amount δ ₂ with a negative sign as the feedback amount FB = −δ ₂ , immediately proceeds to P _38. It should be noted that the FB in this case does not naturally mean the feedback control amount related to the MBT control.

Further, when it is determined that θM ₁ ≦ θpmax ≦ θM ₂ in P _33, the engine is not in a transient state, yet the crank angle θ
Since pmax is controlled within the target crank angle range, learning and storage processing of the feedback amount FB is performed. However, immediately after the transient operation, i.e. a few seconds immediately after the acceleration or deceleration (T ₁ second), because the influence of vibration or the like torsion of the crankshaft of the response delay and the engine of the air flow meter 3, after acceleration at P ₄₁ T ₁ (It is desirable to change it according to the operating condition of the engine and the cooling water temperature) Check whether or not seconds have passed,
T If ₁ second has not elapsed, postpone learning and memory processing P
Proceed to ₃₈ . In P ₃₈ , when proceeding from P ₄₀ , FB = −δ ₂
When the process proceeds from P ₄₁ , each final ignition timing ADV is calculated by the formula using the previous feedback amount FB. It is assumed that the value of FB is reset to −δ ₂ or zero between P ₃₂ and P ₃₃ immediately after shifting from the acceleration operation to the steady operation. At P ₄₂ , it is determined whether the feedback amount FB is zero, and if FB = 0, at P ₄₃ AD1
Because of the rewrite process is not required proceed to P _45, if the FB ≠ 0, the process proceeds to P _43. At P ₄₃ , the engine was warmed up sufficiently and the engine was not in a transient operation state, and the crank angle θpmax
Is within the target crank angle range, T ₁ seconds has elapsed after transient operation, and FB ≠ 0. Therefore, the feedback value FB is used as the learning value ADV1, and the learning value ADV1 is updated to the learning table grid point for ADV1 in NVM24. Remember. If the actual engine speed data and engine load data do not match the two data that define the grid points in the learning table,
After weighting (interpolating) the FB in consideration of such shifts, the value obtained thereby is updated and stored in the approximate grid point (the reverse processing is performed at the time of the table look up at P ₂₀ in FIG. 9). ).

In addition, the feedback amount FB updated and stored in this P ₄₃
Is always subjected to the processing of P ₃₅ or P ₃₇ described above, the feedback amount FB can be regarded as a correction amount of the ignition timing based on the crank angle θpmax.

In P _44, a feedback amount that is used for program at P ₄₃
Clear FB to zero. In P _45, obtained in the P ₂₀ of FIG. 9
Final ignition timing AD from new ADV1 rewritten with ADVφ and P ₄₃
Calculate V by the following formula.

ADV = ADVφ + ADV1 ...... Moreover, when it is judged that the engine is decelerating in P ₃₂ or when FB = 0 is judged in P ₄₂ , it is directly P ₄₅ respectively.
Although coming proceed to, the ADV1 used when this such a ADV1 determined by P ₂₁ of FIG. 9.

Returning to FIG. 9 again, at P ₂₆ , various processes relating to knocking avoidance control as shown in FIG. 11 are performed.

First, at P ₅₀ , the value obtained by subtracting a predetermined amount δ ₃ to be retarded at each ignition from the previous feedback amount KFB (a value as a retard correction amount for avoiding knocking, the initial value is zero) is fed back this time. Perform the retard correction process to set the amount KFB and proceed to P ₅₁ . By performing the same processing as P ₃₁ in FIG. 10 in P _51, if the engine is in acceleration proceeds to P _53, the engine is accelerating (during the transient operation) unless the process proceeds to P _52. In P _52,
After acceleration T ₂ (T ₁ ≧ T ₂ : This T ₂ is also preferably changed according to the engine operating condition and cooling water temperature) Check whether or not seconds have elapsed, and if T ₂ seconds have not elapsed, P Proceed to ₅₃ , and if T ₂ seconds have elapsed, proceed to P ₅₄ . In P ₅₃ , P in Fig. 8
_{20, ADVφ} obtained in P _21, the final ignition timing ADV for knocking avoidance is calculated by the following equation based on the feedback amount KFB determined by ADV1 and P _50.

ADV = ADVφ + ADV1 + KFB elapsed ...... P In ₅₄ after the acceleration at least T ₂ seconds and is in a stable state engine is not excessive operation state (the retard correction amount of ignition timing by knocking avoidance control) feedback amount KFB in this case as learned value ADV1, proceeds to P ₅₅ after updating stored in the lattice point of the learning table of ADV1 in NVM24 determined by the engine speed data and engine load data at this time. In P _55, obtained in the P ₂₀ of FIG. 9 A
Using the new ADV1 rewritten in DVφ and P _54, the final ignition timing ADV at the table rewriting, it is calculated by the following equation.

ADV = ADVφ + ADV1 ...... In the present knocking avoidance control routine, the normal operation after the deceleration or deceleration of the engine, for example it is assumed that the processing of the P ₅₃ is performed (AD even during steady operation after deceleration
You may rewrite V1).

Returning to FIG. 9, in P ₂₅ executed after the MBT control of P ₂₄ or the knocking avoidance control of P ₂₆ is performed, P ₃₈ , P
₄₅ , P ₅₃ and P ₅₅ (see Fig. 10 or Fig. 11) The final ignition timing ADV obtained by subtracting from 70 ° CA (7
0-ADV) is output to the register of the input / output control circuit 25 in FIG. 2, and then the processing of this processing program is once terminated.

Then, every time the above processing is performed (70-AD
When the value V) is written in the register of the input / output control circuit 25, the ignition signal S ₁₀ is formed and output to the power transistor Q ₁ of the ignition unit 26 as follows.

That is, in the input / output control circuit 25, the counter value is reset to zero when the reference position signal S ₁ is input from the crank angle sensor 2 as shown in, for example, FIGS. Each time the signal S ₂ is input, the counter value is incremented by 1 every 1 ° CA at the rising and falling edges thereof. On the other hand, the register has been written 70-ADV as described above at a predetermined timing, by comparing the value of this register and the value of the aforementioned counter, the spark signal S ₁₀ when both match Unit 2
Output to 6 power transistor Q ₁ . Then, when the above ignition signal S ₁₀ is output to the power transistor Q ₁ ,
This power transistor Q ₁ is turned from ON to OFF, and the high voltage generated on the secondary side of the ignition coil 28 is supplied to the ignition plug (27a
~ 27f) to be ignited.

By operating the control unit 20 as described above, the past history of the ignition timing correction amount by the MBT control and the ignition timing retard correction amount by the knocking avoidance control is always used for the calculation of the current ignition timing. In addition, the MBT control during transient operation is interrupted, so when the operating state of the engine changes, the amount of correction of the ignition timing does not change significantly and torque fluctuation is not caused. Since the ignition timing control is not performed, the engine drivability is improved, and it is possible to prevent knocking to some extent by learning, so the range in which the MBT control is effective is expanded, thereby improving the engine output. Can be achieved.

 The effects of the first embodiment described above will be considered.

(I) Since only the minimum required number of basic data are matched, the matching man-hours can be significantly reduced.

(II) Since insufficient data is sequentially supplemented as supplementary data according to the operating state of the running engine, it does not hinder engine control.

(III) Some data is used only under special operating conditions, but basic data is not stored in such special areas, so the waste of having unused data is eliminated. .

(IV) The replenishment data is updated sequentially according to the actual operating state of the engine and follows the changes with time of the engine, etc., so that the control accuracy can be kept good for a long time.

(V) Unlike the conventional simple interpolation method, the calculation of the supplementary data is performed in the normal calculation format, so the calculation time is short and does not interfere with other control processing.

In the first embodiment, the pressure sensor 10 incorporated in the cylinder gasket has been described as an example, but the present invention is not limited to this. For example, a pressure sensor having a washer-like piezoelectric element incorporated in each spark plug as a washer. Can also be used.

In the first embodiment described above, the ignition timing control device for the internal combustion engine that performs both the MBT control and the knocking avoidance control has been described as an example. However, when only the MBT control is performed, the knocking detection circuit 9 of FIG. 7th with removal
P ₁₂ , P ₁₃ , P ₁₆ in the flow chart of the figure (P in Fig. 11
Can respond by omitting the processes of including) a ₅₀ to P _55,
Also in this case, it goes without saying that the above-mentioned effects corresponding to the configuration can be obtained.

13 to 15 are views showing a second embodiment of the present invention. In the second embodiment, both the basic table and the learning table utilize the memory area in the RAM 23 or NVM 24 to control a part of the basic data. The initialization routine when the power to the unit 20 is turned on is stored in the RAM 23 or the NVM 24.

First, as shown in FIG. 13, 8 × 8 = 64 in the RAM 23 or NVM 24 with the engine speed N as the horizontal axis and the intake air amount Qa as the vertical axis.
A map composed of grid points at equal intervals is provided. Then, for example, in the development stage, the data at the ignition timing of each representative point in the vicinity of idle, the city direct mode area, and the fully open area is examined in detail, and the data is applied to the corresponding portion of the grid point.
A ₁₁ , A ₂₂ , A ₂₅ , A ₂₈ , A ₃₃ , A ₅₂ , A ₅₈ , A ₈₈ are given in advance as constants. The above basic data Aij
Since there is no data at the beginning of the area (data to be learned data) except for, the data around this area is represented by the basic data Aij.

FIG. 14 is a flowchart showing an initialization routine for initially storing the above data in a predetermined area of the RAM 23 or NVM 24. First, the basic data Aij given as described above is not initially stored in the RAM 23 or the NVM 24 and is called by the initial program.
Therefore, in P ₇₁ , the basic data Aij is stored in the corresponding predetermined area at the same time when the control unit 20 is powered on. This store area is shown as in FIG. Then
In P ₇₂ , the learning data aij is stored in a predetermined area.First, since there is no data in RAM23 or NVM24, it is obtained by performing interpolation calculation of the value of aij from multiple adjacent Aij, and the first data is After being decided, by so-called learning control
The value of aij is updated sequentially. Note that the value of Aij may also be sequentially updated by learning control, and if so, the data is updated as data with higher accuracy than the entire map value, and control accuracy is increased. Note that the above example is an example in which the data aij is interpolated from the basic data Aij, but in order to speed up the arithmetic processing, the corresponding area of aij is represented by one of the values of Aij as follows. Alternatively, the value may be updated by learning calculation after the second time.

a ₂₁ = a ₂₁ = A ₁₁ , a ₃₁ = a ₃₂ = a ₁₃ = a ₂₃ = A ₂₈ , a ₄₁ = a ₄₂ = a ₄₃ = a ₁₄ = a ₂₄ = a ₃₄ = a ₄₄ = A ₂₈ , a ₅₁ ＝ a ₆₂ ＝ a ₇₁ ＝ a ₈₁ ＝ a ₆₂ ＝ a ₇₂ ＝ a ₈₂ ＝ a ₅₃ ＝ a ₆₃ ＝ a ₇₃ ＝
a ₈₃ = A ₈₅ , a ₁₅ = a ₁₈ = a ₂₆ = a ₃₅ = a ₄₅ = a ₃₆ = a ₄₆ = A ₂₅ , a ₅₄ = a ₆₄ = a ₇₄ = a ₈₄ = a ₆₄ = a ₇₅ = a ₈₅ ＝ a ₅₆ ＝ a ₆₆ ＝ a ₇₆ ＝
a ₈₆ = A ₅₅ , a ₁₇ = a ₂₇ = a ₃₇ = a ₁₈ = a ₃₈ = A ₂₈ , a ₄₇ = a ₅₇ = a ₆₇ = a ₄₈ = a ₆₈ = A ₅₈ , a ₇₇ = a ₈₇ = a ₇₈ = A ₈₈ , Fig. 15 is a flow chart showing a program for ignition timing control. The table lookup of ADV1 is carried out at P _91. This table lookup method is stored in RAM23 or NVM24 by the initialization routine described above. It is determined by looking up Aij and aij, and the process proceeds to the steps after P ₂₂ to perform the same processing as in the first embodiment.

Therefore, in this second embodiment, the ROM 22 is not used as the storage area for the basic ignition timing data in the ignition timing control, but the RAM 23 and the NVM 24 are used, and the basic data given in the initializing routine is very small, about several pieces. Basic data that is calculated and given in advance
The same effects as those of the first embodiment can be obtained in all, such as the number of Aij can be reduced and the man-hours for engine matching and the development cost can be reduced.

Further, the difference from the first embodiment is that even basic data can be sequentially updated by later learning control, which allows more accurate engine ignition timing control.

Although the first and second embodiments are examples in which the present invention is applied to ignition timing control of an internal combustion engine, the application of the present invention is not limited to this. In short, it can be applied to all that control the internal combustion engine by using a microcomputer. For example, in addition to ignition timing control, fuel injection control,
The present invention can be applied to any EGR control, supercharging pressure control, or the like that has a map inside the microcomputer and performs control based on this map value.

(Effect) According to the present invention, it is necessary to match only a minimum number of basic data, which is the minimum required, so that the number of matching steps can be significantly reduced. Further, since the lacking data is supplemented as supplementary data in accordance with the operating state of the running engine, it is possible to prevent the engine control from being disturbed. Also, some data is used only under special operating conditions, but basic data is not stored in such special areas, so it is possible to save the waste of having unused data. it can. Further, the replenishment data is sequentially updated according to the actual operating state of the engine and well follows the change with time of the engine and the like, so that the control accuracy can be maintained good for a long period of time.

[Brief description of drawings]

FIG. 1 is a basic conceptual diagram of the present invention, FIGS. 2 to 12 are diagrams showing a first embodiment of the present invention, FIG. 2 is a block diagram of an essential part including its control unit, and FIG. FIG. 4 is a detailed block diagram of the knocking detection circuit, FIG. 4 is a diagram showing the operation of the knocking detection circuit of FIG. 3, FIG. 5 is a flow chart showing a program of its basic principle, and FIG. 6 is a diagram showing its learning table. , FIG. 7 is a flow chart showing the program for the θpmax detection, FIG. 8 is a waveform chart showing the signal processing waveform, FIG. 9 is a flow chart showing the ignition timing control program, and FIG. 10 is the MBT of FIG. FIG. 11 is a flowchart showing a control program, FIG. 11 is a flowchart showing a knocking avoidance control program of FIG.
FIG. 12 is a timing chart showing the operation of the counter in the input / output control circuit, FIGS. 13 to 15 are diagrams showing a second embodiment of the present invention, and FIG. 13 is a table map for obtaining the basic ignition timing. FIG. 14 is a flow chart showing the initial program, FIG. 15 is a flow chart showing a program for the ignition timing control, and FIG. 16 is a view showing a basic table for obtaining the basic ignition timing showing the conventional ignition timing control. . 10 ... Operating state detection means, 21 ... CPU (supplementary data storage means, update means, control value calculation means), 22 ... ROM (data area, basic data storage means), 23 ... RAM (data area), 24 …… NVM (data area), 26 …… Ignition unit (operating means).

Claims (1)

(57) [Claims] 1. A) operating state detection means for detecting an operating state of an engine; b) a data area having a plurality of storage areas individually referred to according to the operating state of the engine; and c) a data area. Partly, basic data storage means for storing in advance basic data necessary for controlling the engine, and d) when an empty area in which no data is stored is referred to by the operating state of the engine, the area of the area close to the empty area is referred to. While calculating supplementary data based on the stored data,
Replenishment data storage means for storing the replenishment data in the empty area, and e) when the operating state of the engine refers to an area in which the replenishment data has already been stored, the stored replenishment based on the operating state of the engine. Updating means for updating data, f) control value calculating means for calculating a control value for controlling the engine based on the stored data in the area referred to by the operating state of the engine, and g) control of the engine based on the control value. A control device for an internal combustion engine, comprising: an operating means for operating a parameter related to.