JPH0330707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for processing and calculating operating parameter signals of an internal combustion engine, and in particular, to supplying detected values of operating parameters to a microcomputer;
The present invention relates to a method of processing a predetermined operating parameter signal according to an engine rotation range and calculating a basic control amount and its correction amount based on the detected value of the parameter signal.

In recent years, for example, in vehicles, for example, microcomputers are used to perform predetermined processing calculations based on various operating parameter values of the internal combustion engine detected by various sensors, and the operating performance and exhaust gas characteristics of the engine are determined based on the processing calculation results. Methods are being adopted to improve various characteristics such as these and to improve driving safety. In order to quickly respond to engine operating conditions that change from time to time, the processing and calculations are generally performed in synchronization with the rotation of the engine. In this method, each cycle (hereinafter referred to as a cycle) consisting of the input, processing and calculation of the above-mentioned operating parameter signal, and the output of a control output based on the calculation result, has a limit determined depending on the engine rotation speed. must be completed within the specified time. That is, each cycle must be completed within a time period corresponding to each pulse interval of a predetermined rotation angle position signal (for example, a top dead center signal) of the engine. On the other hand, for the microcomputer to complete each cycle, a predetermined calculation time determined by the capability of the microcomputer is required. Therefore, in the high rotation range of the engine, the engine rotation angle position signal pulse interval becomes short, so
There may be cases where the microcomputer is unable to completely execute each of the above cycles within the time corresponding to this pulse interval.

In order to solve this problem, conventionally, for example, a method has been adopted in which predetermined processing and calculation contents are divided into at least two parts and each part is executed alternately or sequentially in synchronization with engine rotation. However, according to the above method, signal processing and calculations are not performed based on the values read at the input of each synchronization signal, for example, the top dead center signal pulse, but are based on the parameter values read at the time of inputting the previous or previous synchronization signal pulse. Since the processing and calculations for each part are performed based on this, it is not possible to respond immediately to sudden changes in engine operating conditions or sudden modulations of the control device, which may result in problems such as deterioration of engine characteristics.

The present invention has been made to solve the above-mentioned problems, and it inputs detected value signals of various operating parameters of an internal combustion engine into a microcomputer and synchronizes them with a reference pulse signal generated in response to engine rotation. Processing and calculation of operating parameter signals of an internal combustion engine, which performs predetermined processing of these parameter detection value signals, and calculates a basic amount of control amount of engine operation and its correction amount based on the parameter detection value. In the method, an engine rotation speed is detected, and based on the detected value of the engine rotation speed, it is determined whether the engine rotation speed is a predetermined rotation speed or more, and it is determined that the engine rotation speed is the predetermined rotation speed or more. Sometimes, by omitting a part of the predetermined processing and the calculation of the correction amount that have little effect on the control amount, the remaining predetermined processing and at least the calculation of the basic amount may be omitted. The present invention provides a method for processing and calculating operating parameter signals of an internal combustion engine, which can be performed for each of the reference pulse signals.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of an apparatus to which the operating parameter signal processing and calculation method of the present invention is applied. Reference numeral 1 indicates, for example, a four-cylinder internal combustion engine, and engine 1 has four main combustion chambers and four main combustion chambers. The combustion chamber is of the type consisting of an auxiliary combustion chamber (both not shown) that communicates with the combustion chamber. An intake pipe 2 is connected to the engine 1, and the intake pipe 2 includes a main intake pipe communicating with each main combustion chamber and a sub-intake pipe (both not shown) communicating with each sub-combustion chamber. A throttle body 3 is provided in the middle of the intake pipe 2, and a main throttle valve and a sub-throttle valve (both not shown) disposed inside the main intake pipe and a sub-intake pipe, respectively, are provided in conjunction with each other. A throttle valve opening sensor 4 is connected to the main throttle valve to convert the valve opening of the main throttle valve into an electrical signal and send it to an electronic control unit (hereinafter referred to as "ECU") 5. Further, an air passage 6 having one end open to the intake pipe 2 is provided on the downstream side of the throttle body 3, and an air cleaner 7 is attached to the other end of the passage 6 communicating with the atmosphere. The auxiliary air amount control valve 8 disposed in the middle of the air passage 6 is a normally closed solenoid valve, and is composed of a solenoid 8a and a valve 8b that opens the air passage 6 when the solenoid 8a is energized. is an electronic control unit (hereinafter referred to as “ECU”)
) 5.

A fuel injection device 9 is provided in the intake pipe 2 between the engine 1 and the throttle body 3. This fuel injection device 9 consists of a main injector 9a and a sub-injector 9b.
A is provided in the main intake pipe slightly upstream of an intake valve (not shown) for each cylinder, and only one sub-injector 9b is provided in the sub-intake pipe slightly downstream of the sub-throttle valve in common to each cylinder. The fuel injection device 9 is connected to a fuel pump (not shown).
Main injector 9a and sub injector 9b
is electrically connected to the ECU 5, and the valve opening time of fuel injection is controlled by a signal from the ECU 5.

On the other hand, absolute pressure sensors 12 and 13 for low pressure region and high pressure region are provided immediately downstream of the main throttle valve of the throttle body 3 via pipes 10 and 11. The absolute pressure signals converted into electrical signals are sent to the ECU 5 when the absolute pressure in the intake pipe is less than a predetermined pressure and when it is above a predetermined pressure, respectively.

Further, an intake air temperature sensor 14 is installed downstream thereof, and this intake air temperature sensor 14 converts the intake air temperature into an electrical signal and sends it to the ECU 5.

Engine water temperature sensor 15 is installed in the main body of engine 1.
The sensor 15 is made of a thermistor or the like, and is inserted into the circumferential wall of the engine cylinder filled with cooling water, and supplies the detected water temperature signal to the ECU 5.

An engine rotation speed sensor (hereinafter referred to as "Ne sensor") 16 and a cylinder discrimination sensor 17 are installed around the camshaft or crankshaft (not shown) of the engine 1, and the former Ne sensor 16 is connected to the TDC
The latter cylinder discrimination sensor 1 is activated at a predetermined crank angle position every 180° rotation of the engine crankshaft.
Reference numeral 7 outputs one pulse each time a specific cylinder rotates at a predetermined crank angle, and these pulses are sent to the ECU 5.

A three-way catalyst 19 is arranged in the exhaust pipe 18 of the engine 1, and performs a purifying action on HC, CO, and NOx components in the exhaust gas. On the upstream side of this three-way catalyst 19,
An O ₂ sensor 20 is inserted into the exhaust pipe 18 , and this sensor 20 detects the oxygen concentration in the exhaust gas and supplies the detected value signal to the ECU 5 .

Furthermore, a sensor 21 that detects atmospheric pressure, a starter switch 22 and a battery electrode 23 of the engine are connected to the ECU 5, and a detected value signal from the atmospheric pressure sensor 21, a voltage signal from the battery electrode 23, and a starter switch 22 are connected to the ECU 5. on/off
An off-state signal is provided.

Reference numeral 24 indicates an electrical device such as a headlight or an air conditioner, and this electrical device 24 is electrically connected to the ECU 5 via a switch 25. Reference numerals 26 and 27 respectively detect engagement and disengagement of a clutch (not shown) of the engine, and detect whether a clutch switch that outputs an on signal when the clutch is engaged and a transmission gear are in a neutral position. shows a neutral switch that outputs an on signal at the position of
Both are connected to ECU5 in series. The output signals of the switches 26 and 27 are, for example, the coefficient values described below.
K Used when calculating _AFC .

In addition, a three-way catalyst 1 is provided in the exhaust pipe 18 of the engine 1.
A turbine 28a of the supercharger 28 is disposed on the upstream side of the throttle body 3, and this turbine 28a is rotated by exhaust gas from the engine 1. The compressor 28b connected thereto is driven.

The idle adjustment means 29 has a variable resistance, for example, and is configured to be able to set the voltage V _IDL .
V _IDL is the basis for calculating the correction constant T _IDL that corrects the fuel injection time T _OUTM so as to obtain the optimum air-fuel ratio for the engine's idling operating state. For example, when assembling the fuel injection device 9 into the engine 1 Set during the process.

The alarm device 44 is an alarm display device made of, for example, a light emitting diode and arranged on the driver's seat panel, and is configured to display an alarm based on a drive signal supplied from the ECU 5 in accordance with the result of failure determination, which will be described later.

FIG. 2 is a diagram showing the circuit configuration inside the ECU 5 shown in FIG.
It is supplied as a TDC signal to the central processing unit (hereinafter referred to as CPU) 31, and is also supplied to the engine rotation speed measurement counter (hereinafter referred to as Me counter) 3.
2 is also supplied. The Me counter 32 counts the time interval from the input of the previous TDC signal from the engine rotation speed sensor 16 to the input of the current TDC signal, and the counted value Me is proportional to the reciprocal of the engine rotation speed Ne. The Me counter 32 sends this count value Me to the CPU 31 via the data bus 33.
supply to. Further, the output signal of the cylinder discrimination sensor 17 is waveform-shaped by the waveform shaping circuit 34 and then
It is supplied to the CPU 31.

On the other hand, throttle valve opening sensor 4, absolute pressure sensor 12 for low pressure region, absolute pressure sensor 13 for high pressure region, intake temperature sensor 14, water temperature sensor 15, O ₂ sensor 2
0, the output signals of the atmospheric pressure sensor 21 and the battery 23 (only some of which are shown) are applied to a level correction circuit 35, and after being corrected to a predetermined voltage level in the circuit 35, the output signals are operated based on instructions from the CPU 31. A multiplexer 36 supplies the signals sequentially to an analog-to-digital converter 37 . The converter 37 converts the output signals of the aforementioned sensors into digital signals, and supplies the digital signals to the CPU 31 via the data bus 33. Further, the output signals from the starter switch 22, clutch switch 26, and neutral switch 27 are supplied to an input circuit 38 that includes a level correction circuit and operates based on commands from the CPU 31, and after level correction, are sent via the data bus 33. and is supplied to the CPU 31.

This CPU 31 is further connected to a read-only memory (hereinafter referred to as ROM) 39 and a random access memory (hereinafter referred to as ROM) via a data bus 33.
(referred to as RAM) 40 and drive circuits 41, 4
2,43. The ROM39 is
The control program executed by the CPU 31 and the reference value Ti _M of the valve opening time of the main injector 9a and sub-injector 9b (FIG. 1), which will be described later,
It stores various data such as Ti _S and coefficient values or constant values corresponding to the values of various engine parameters. Further, the RAM 40 temporarily stores the calculation results of the CPU 31 and the like.

Then, according to the control program stored in the ROM 39, the CPU 31 reads coefficient values or constant values corresponding to the output signals of the respective sensors described above from the ROM 39, and opens the valves of the main and sub-injectors 9a and 9b based on the above calculation formula. Time T _OUTM , T _OUTS
is calculated, and the value obtained by this calculation is supplied to the drive circuit 41 via the data bus 33. The drive circuit 41
supplies a control signal to the fuel injection device 9 to open the main and sub-injectors 9a and 9b over the calculated valve-opening times T _OUTM and T _OUTS . Further, the CPU 31 calculates the amount of auxiliary air depending on the engine operating state, that is, the opening time of the auxiliary air amount control valve 8, and supplies the value obtained by this calculation to the drive circuit 42 via the data bus 33. The circuit 42 opens the control valve 8 during the valve opening time. Furthermore, the CPU 31 performs a predetermined failure determination to be described later.
When at least one failure determination condition is satisfied, an alarm signal corresponding to the determination result is supplied to the drive circuit 43 via the data bus 33 to activate the alarm device 44 and to store in the RAM 40 that there is a failure state. Instead of this RAM 40, a nonvolatile random access memory (not shown) may be configured to store the failure state.

Next, a case will be described in which the method of the present invention is applied to the fuel injection device 9 having the above-described configuration.

First, FIG. 3 is a block diagram showing the program structure according to the method of the present invention, which consists of a main program 1 and a subprogram 2.
The main program 1 performs control in synchronization with the TDC signal based on the engine rotation speed Ne, and consists of a starting control subroutine 3, a basic control program 4, and a high rotation control program 5. This consists of an asynchronous control subroutine 6 for cases where synchronization is not performed.

The basic calculation formula in the starting control subroutine 3 is expressed as T _OUTM = Ti _CRM × K _Ne + T _ACC + (T _V + ∆T _V ) ... (1) T _OUTS = Ti _CRS × K _Ne + T _V ... (2) It will be done. Here, Ti _CRM and Ti _CRS are reference values for the valve opening times of the main and sub-injectors, respectively, and are determined by the starting Ti table 7, respectively. K _Ne is a correction coefficient at the time of starting specified by the engine speed Ne, and is determined by the K _Ne table 8. T _ACC is a constant during acceleration and is determined in acceleration subroutine 9. T _V is a constant for correcting the increase or decrease of the valve opening time according to changes in battery voltage, and is obtained from _TV table 9. _TV is for the sub-injector, while the injector for the main injector is different due to the difference in structure. The amount of ΔT _V is increased according to the operating characteristics of.

In addition, the basic calculation formula in basic control program 4 is: T _OUTM = T _iM × (K _TA・K _TW・K _AFC・K _PA・K _AST・K _WOT・K
_O2・K _LS )＋T _ACC × (K _TA・K _TWT・K _TAST・K _PA )＋T _AIC +T _IDL + (T _V
+ΔT _V )...(3) T _OUTS = Ti _S × (K _TA・K _PA ) + T _V ...(4) Here, Ti _M and Ti _S are reference values for the valve opening times of the main and sub-injectors, respectively, and are calculated from the basic Ti map 11, respectively. This basic Ti map 11 is composed of, for example, a memory, and stores reference values for the amount of fuel supplied according to the engine speed Ne and the intake pipe internal pressure (absolute pressure) P _BA . The reference values Ti _M and Ti _S are multiplied
Various coefficients such as K _TA , K _TW . . . are calculated by respective tables and subroutines 12. K _{T A}
is the intake air temperature correction coefficient, calculated from the table based on the actual intake air temperature, and K _TW is the actual engine water temperature.
T _W is the fuel increase coefficient determined from the table, K _AFC is the fuel increase coefficient after fuel cut determined by the subroutine, K _PA is the atmospheric pressure correction coefficient determined from the table according to the actual atmospheric pressure, K _AST is the post-start fuel increase coefficient determined by the subroutine, K _WOT is a constant and is the enrichment coefficient of the air-fuel mixture when the throttle valve is fully opened, and K _O2 is determined by the subroutine according to the actual oxygen concentration in the exhaust gas. The obtained O ₂ feedback correction coefficient, _KLS , is a constant and is a lean coefficient of the air-fuel mixture during lean/stoichiometric operation. Stoiki is
Stoichiometric is an abbreviation for stoichiometric amount, or stoichiometric air-fuel ratio.

T _ACC etc. in the second term of equation (3) above are as described above, K _TAST is the post-start increase coefficient obtained by the subroutine, and K _TWT is the synchronous acceleration calculated based on the water temperature increase coefficient K _TW . , is the fuel increase coefficient after acceleration and during asynchronous acceleration. Furthermore, T _AIC in the third term and T _IDL in the fourth term of the same equation are the increase value during idle rotation speed control determined by the subroutine and the idle air-fuel ratio adjustment value determined from the table, respectively. T _V in the fifth term of the same equation,
ΔT _V is as described above.

Next, the basic calculation formula for high rotation control program 5 is: T _OUTM = Ti _M × (K _TA × K _PA・K _TW・K _WOT・K _O2・K _LS ) + T
It is expressed as _IDL + ( _TV + ΔT _V )...(5) T _OUTS = Ti _S × (K _{TA ·} K _PA ) + TV (6). Ti _M in the above formulas (5) and (6),
Various coefficients and constants such as Ti _S and K _TA are as described above. However, T _IDL is preferably not determined by a subroutine as described later, but is calculated and stored in the RAM 40 before entering the high rotation range and is used.

On the other hand, the formula for calculating the valve opening time T _MA of the main injector 9a, which is not synchronized with the TDC signal, in the asynchronous control subroutine 6 is: T _MA = Ti _A ×K _TWT・K _AST + (T _V + ΔT _V ) ……( 7) is expressed as Here, Ti _A is a fuel increase reference value during acceleration control that is asynchronous during acceleration, that is, not synchronized with the TDC signal, and is determined from the Ti _A table 13. K _TWT is the water temperature increase coefficient K _TW shown in Table 1.
Synchronous acceleration obtained from 4 and calculated based on it,
This is the fuel increase coefficient after acceleration and during asynchronous acceleration. The other coefficients _KAST, etc. are as described above.

Furthermore, in addition to the content for calculating the fuel injection amount, the main program 1 includes content that enables processing of predetermined operating parameter signals such as failure determination, which will be described later.

FIG. 4 shows a flowchart of the main program 1, which consists of an operating parameter signal processing block A, a starting control block B, a basic control block C, an operating parameter signal processing block D during high rotation, and a high rotation It consists of a time control block E. First, in the input signal processing block A, when the starter switch 22 shown in Fig. 1 is turned on, the CPU
31 is initialized (step 1), and the TDC signal is input when the engine starts (step 2). Next, the elapsed time from the first TDC signal to the next TDC signal is counted, and based on that value, the engine speed Ne is calculated and stored in the ECU 5 (step 3), and the engine speed is determined based on the calculated value of Ne. It is determined whether or not the number is less than a predetermined number of rotations Nz (step 4). This predetermined rotation speed Nz
is set to a rotational speed, for example, 4250 rpm, which is lower than the rotational speed at which inconveniences may occur if all processes such as predetermined operation parameter signal processing that are performed when the engine rotational speed Ne is less than the engine rotational speed Nz. Preferably, the value of this predetermined rotation speed Nz is set to 4500 rpm when entering the high rotation range, and to 4000 rpm when exiting the high rotation range, and the value of the fuel when the engine is operated near the rotation speed Nz Operational shocks due to fluctuations in the injection amount are prevented from occurring.

If the answer to the determination in step 4 is affirmative (Yes), then all basic analog values from each sensor are atmospheric pressure P _A , absolute pressure P _BA , P _BATC , engine water temperature T _W , and atmospheric pressure T _A , throttle valve opening θth and
The output voltage V of the O ₂ sensor, the setting voltage V _IDL of the idle adjustment means 29, and the battery voltage V _B are output to the ECU.
5, and furthermore, the starter switch 22,
The on/off states of the clutch switch 26 and neutral switch 27 are read into the ECU 5,
Necessary values are stored and a predetermined failure determination is performed by a subroutine to be described later (step 5).

Next, when the difference between the absolute pressure readings this time and the time before the previous time is more than a predetermined value, the formula P _BA = P _BAo +
The predicted absolute pressure P _BA is calculated by (P _BAo −P _BAo-1 ) (Step 6). is a calibration variable, and subscripts n and n-1 indicate the current time and the previous time, respectively. At low engine speeds, especially when the engine load changes suddenly, the actual value of the absolute pressure in the intake pipe at the time when the detected absolute pressure value P _BA and the injection amount calculated based on this value are supplied. Since the difference between the values becomes large and the fuel injection amount based on the detected value may become inappropriate, the predicted absolute pressure P _BA , that is, the estimated value close to the actual value, is used to perform fuel injection that immediately responds to the engine operating state. It is.

Next, an acceleration correction constant _TACC is set and deceleration processing is performed (step 7). First, calculate the difference Δθn between the current value θn and the previous value θ _o-1 of the throttle valve opening θth, and the difference ΔΔθn between the current difference Δθn and the previous difference Δθ _{o-1 .} do. Then, based on the values of Δθn and ΔΔθn, it is determined whether the engine is in an operating state during acceleration or after acceleration. During acceleration, T _ACC is set to a larger value as Δθn is larger, and after acceleration, T _ACC is set to a value that gradually decreases until a predetermined number of TDC signals are input. On the other hand, when it is determined based on Δθn and ΔΔθn that the vehicle is decelerating or within a predetermined time after deceleration, the basic
Instead of the Ti map value Ti _M , the value calculated by the formula Ti _M × R _M (R _M is a calibration coefficient and takes a value of 0.5 to 1.0) is used to reduce the fuel injection amount.

Next, it is determined whether the engine speed Ne is less than or equal to the cranking speed (starting speed) (step 8), and if the answer is yes, the engine is sent to the starting control block B. , determine the battery voltage correction constants T _V and ΔT _V using the T _V table (step 9), and calculate the correction coefficient based on the engine speed Ne.
Determine KNe by KNe table (step
10), Ti _CRM and Ti _CRS are further determined based on the engine water temperature Tw using the starting Ti table (step 11). The numerical values obtained in this way are expressed in the previous equations (1) and (2).
Calculate T _OUTM and T _OUTS by substituting
12).

If the answer is No in step 8, it is sent to basic control block C, which determines whether or not the engine is in a state where fuel should be cut (step 13), where the answer is affirmative (Yes).
If so, the values of T _OUTM and T _OUTS are both set to zero and a fuel cut is performed (step 14).

On the other hand, if the answer to step 13 is No, each correction coefficient K _TA , K _TW , K _AFC ,
K _PA , K _AST , K _WOT , K _O2 , K _LS , K _TWT , K _{TAST ,} etc. and correction constants T _AIC , T _IDL , T _V , ΔT _V are calculated (step 15). These correction coefficients and constants are determined by subroutines, tables, etc., respectively.

Next, a predetermined corresponding map is selected according to each data such as the rotational speed Ne, absolute pressure P _BA , P _BATC, etc., and Ti _M and Ti _S are determined based on the map (step
16). Then, T _OUTM and T _OUTS are calculated by the above equations (3) and (4) based on the correction coefficient value, correction constant value, and reference value obtained in steps 15 and 16 (step 17). And the thus obtained T _OUTM , T _OUTS
The main and sub-injectors are operated based on the values of (step 18).

If the answer to step 4 is negative (No),
Processing block D for operating parameter signals at high rotation speeds
Atmospheric pressure P _A , absolute pressure P _BA , P _BATC , engine water temperature T _W , atmospheric temperature T _A , throttle valve opening θth,
O ₂ sensor output voltage V and battery voltage V _B
It is read into the ECU 5, stores necessary values, and is part of the failure determination performed in step 5 according to the subroutine described later.For example, absolute pressure sensors 12, 13
(Step 19) The operating parameter signals are selected from operating parameter signals that are highly important (substantially have a large influence on the control amount, fault determination, etc.) in calculating the fuel injection amount at high rotational speeds, fault determination, and the like.

Next, the deceleration process described in step 7 of control block A is performed (step 20), and the process is sent to high rotation control block E.

First, it is determined whether or not the engine is in a state that requires a fuel cut (step 21). If the answer to this determination is affirmative (Yes), the values of T _OUTM and T _OUTS are both set to zero and a fuel cut is performed (step 21).
14). On the other hand, if the answer is negative (No), each correction coefficient K _TA , K _TW , K _PA , K _O2 , L _LS , K _WOT and correction constants T _V and ΔT _V are calculated. These correction coefficients and correction constants are determined by subroutines, tables, etc., as in step 15 (step 22). Then, approximate engine speed Ne
A predetermined corresponding map is selected according to each data such as absolute pressure P _BA , P _BATC etc.
Determine Ti _M and Ti _S (Step 23). Then, based on the correction coefficient values, correction constant values, and reference values obtained in steps 23 and 24 above, T _OUTM and T _OUTS are calculated using the calculation formulas (5) and (6) at high rotation.
(Step 24).

As a result of simply determining the fuel injection amount at high rotation as described above, the number of types of correction coefficients etc. to be calculated is reduced, and the calculation execution time in the microcomputer is significantly shortened. On the other hand, since the omitted correction coefficients and the like are of low importance in calculating the fuel injection amount at high engine speeds, the negative effects associated with their omission can be minimized. Correction coefficients that can be omitted at high speeds include, for example, the after-start increase coefficient K _AST , the after-fuel cut increase coefficient K _AFC , the water temperature increase coefficient K _TWT ,
Accelerated bulking constant T _ACC and AIC bulking constant T _AIC .

The coefficient K _AST is used for the increase correction to stabilize the engine rotation at the time of starting, and is set to a smaller value as the engine speed increases at the time of starting, so it is important for correction at high engine speeds. It is not a significant coefficient. The coefficient K _AFC is used, for example, to prevent engine stall after the fuel cut is completed.
This can be omitted since there is little risk of engine stalling at high speeds. In general, in a high engine speed range, the air flow rate in the combustion chamber increases, so the allowable range of air-fuel ratio for normal combustion tends to widen, and secondary correction factors such as acceleration increases are hardly required. On the other hand, the constant T _ACC is a correction constant to compensate for the lack of fuel supply due to a delay in the increase in absolute pressure PBA when the throttle valve opening θth increases rapidly. Since the delay in following the throttle valve opening of the PBA is also alleviated, this constant T _ACC can be omitted at high speeds. Therefore, all coefficients of the constant T _ACC that apply only to the constant T _ACC , such as the warm-up increase coefficient during acceleration, can be omitted. The constant T _AIC is used, for example, for increase correction to avoid engine stalling when an electrical load is applied at low engine speeds, and can be omitted at high engine speeds.

In addition, in the basic T _i map, the engine speed
Regarding Ne, for example, in the range of 0 to 6000 rpm, N ₁ to
There are 16 stages of N ₁₆ , and at low speeds the rotational speed Ne
When the injection amount is an intermediate value other than N ₁ to N ₁₆ , the injection amount is calculated by interpolation using an interpolation method, whereas at high rotation speeds, when the rotation speed Ne is an intermediate value, the injection amount is calculated from N ₁ to N 16.
By using the closest value of _N16 , that is, the approximate rotational speed, interpolation calculation is omitted and calculation time is shortened. Furthermore, the calculated correction constant value T _IDL
Instead, the calculation time is reduced by using a correction constant value T _IDL that is calculated and stored before entering the high rotation range.

Then, the fuel injection device 9 is operated based on the values of T _OUTM and T _OUTS obtained in this way (step 18).

FIG. 5 shows a flowchart of a subroutine for fault determination carried out in step 5 of the start-up control block A shown in FIG. It is determined whether the failure determination conditions are satisfied (step 1). The objects of this predetermined failure determination include, for example, the throttle valve opening sensor 4, the main and sub-injectors 9a and 9b, the absolute pressure sensors 12 and 13, the Ne sensor 16, and the cylinder discrimination sensor 1.
7, an O ₂ sensor 20, an atmospheric temperature sensor 21, and an idle adjustment means 29 (FIG. 1).

If the answer to step 1 is negative (No),
The process moves to step 6 (FIG. 4) of the starting control block A (step 2). On the other hand, if the answer to the determination is affirmative (Yes), that is, it is determined that at least one of the predetermined failure determination conditions is satisfied, the abnormal state continues for a predetermined time t _FS i (the subscript i corresponds to each of the above sensors, etc.). It is determined whether the process continues for a timer (not shown) (step 3). If the answer to this determination is negative (No), the process moves to step 6 of the control block A (step 2). On the other hand, if the answer to the determination is affirmative (Yes), the occurrence of an abnormal condition is displayed on the alarm device 44 to issue an alarm, and is also stored in the RAM 40 of the ECU 5 (Step 4), and a predetermined fail-safe operation is performed (Step 5). ).

FIG. 6 shows a flowchart of a subroutine for fault determination performed in step 19 of processing block D of operating parameter signals at high rotation speeds shown in FIG. i.e. t _FS i(i≠
j, where the subscript j indicates a timer corresponding to the absolute pressure sensor) is set to zero (step 1) to prevent the timer not corresponding to the absolute pressure sensors 12 and 13 from running on its own and operating in a fail-safe manner. Next, based on the parameter values read and stored as described above, it is determined whether the failure determination conditions for the absolute pressure sensors 12, 13 are satisfied (step 2).
In this way, during high rotation, the absolute pressure sensor 12,
By not performing abnormality determination for items other than 13, the execution time of step 19 of processing block D can be significantly shortened compared to that of step 5 of control block A, and it is also possible to prevent absolute pressures 12 and 13 from operating abnormally. It is possible to prevent damage to the engine 1 and the three-way catalyst 19 that may occur if the engine continues to be operated based on the output signal despite the fact that the engine is running.

If the answer to the determination in step 2 is negative (No), the process moves to step 20 of processing block D (step 3), and if the answer is affirmative (Yes), that is, at least one of the absolute pressure sensors 12 and 13 is abnormal. If it is determined, it is determined whether the abnormal state continues for a predetermined time _tFSj (step 4). If the answer to this determination is negative (No), the process moves to step 20 of processing block D (step 3).
On the other hand, if the answer is affirmative, an alarm is issued and stored (step 5) in the same manner as described above for step 5 in FIG. 5, and a predetermined fail-safe operation is performed (step 6).

In the above embodiment, the fuel injection amount is calculated based on the parameter values of the engine speed Ne and the intake pipe absolute pressure P _BA , but the intake air amount Qa or the throttle valve opening θth is used instead of the absolute pressure P _BA . The method of the present invention is also applicable to methods that have previously been used.

Furthermore, in the above embodiments, the fuel injection amount was explained as an example of the control variable to which the method of the present invention is applied, but the control variable may also be the ignition timing or the exhaust gas recirculation amount in a device equipped with an exhaust gas recirculation device.

As explained above, according to the present invention, a microcomputer is used to perform predetermined processing of operating parameter signals and predetermined control amounts, etc. based on the parameters in synchronization with a reference pulse signal generated in response to engine rotation. In the method of performing calculations,
Detects the engine rotation speed, determines whether the engine rotation speed is equal to or higher than a predetermined rotation speed, and substantially applies to the control amount as part of the predetermined processing and correction amount calculation when the engine rotation speed is equal to or higher than the predetermined rotation speed. By omitting processing and calculations that have little influence, the remaining predetermined processing and at least the calculation of the basic quantity can be performed for each reference pulse signal,
A method for processing and calculating operating parameter signals of an internal combustion engine that can reliably process operating parameter signals and calculate control variables, etc. required at high engine speeds in synchronization with engine rotation even when the engine is in a high-speed operating state. can be provided.

Further, according to the embodiments of the present invention, operating parameters of the internal combustion engine allow calculation of the fuel injection amount and predetermined correction coefficients that are important even at high rotation speeds, as well as predetermined processing such as failure determination that is important even at high rotation speeds. A signal processing and calculation method is provided, and by applying this method to fuel injection control of a multi-cylinder engine, it is possible to perform sequential injection in a multi-cylinder engine even at high rotation speeds, improve various engine characteristics, and prevent engine failure. Prevention is planned.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram illustrating an apparatus to which the method of the present invention is applied, FIG. 2 is a circuit configuration diagram illustrating the electronic control unit (ECU) shown in FIG. 1, and FIG. A block diagram illustrating a method and a program configuration related to fuel injection amount control using the control output obtained by the method, FIG. 4 is a flowchart of the main program shown in FIG. 3, and FIGS. 5 and 6 are respectively 5 is a flowchart of a failure determination subroutine carried out in the start-up control block and the high-speed operation parameter signal processing block shown in FIG. 4. FIG. In FIG. 1, 1...engine, 5...electronic control unit, 9...fuel injection device, 44...alarm device, in FIG. 3, 1...main program, 3...starting control program, 4...basic control program, 5
... Control program at high speed, in Figure 4, A... Processing block for operating parameter signals, B... Control block at startup, C... Basic control block, D... Processing block for operating parameter signals at high speed, E... High speed. Rotation control block.

Claims (1)

[Claims] 1. Detected value signals of various operating parameters of the internal combustion engine are inputted to a microcomputer, and predetermined values of these parameter detected value signals are input in synchronization with a reference pulse signal generated in response to engine rotation. In a method for processing and calculating operating parameter signals of an internal combustion engine, the processing and calculating a basic amount of a control amount of engine operation and its correction amount based on the detected parameter value. It is determined whether the engine rotation speed is equal to or higher than a predetermined rotation speed based on a detected value of the engine rotation speed, and when it is determined that the engine rotation speed is equal to or higher than the predetermined rotation speed, the predetermined processing and the correction amount are performed. By omitting processes and calculations that have little effect on the control amount in some of the calculations, the remaining predetermined processing and at least the calculation of the basic amount can be performed for each of the reference pulse signals. A method for processing and calculating operating parameter signals of an internal combustion engine, characterized in that: 2. The control amount is the fuel injection time, and the correction amount whose calculation is omitted when it is determined that the engine speed is equal to or higher than the predetermined speed is the increase value after starting, the increase value after fuel cut, the water temperature increase value, and A method for processing and calculating an operating parameter signal of an internal combustion engine as claimed in claim 1, which is at least one acceleration increase value. 3. Claims 1 or 2, wherein the processing of the operating parameter signal that is omitted when it is determined that the engine speed is equal to or higher than the predetermined number of rotations is part of the processing for reading the operating parameter signal. A method for processing and calculating operating parameter signals of an internal combustion engine as described. 4. Claims 1 to 4, wherein the operation parameter processing that is omitted when it is determined that the engine rotation speed is equal to or higher than the predetermined rotation speed is a failure determination process for at least one of the input system of the operation parameter signal. 4. A method for processing and calculating operating parameter signals of an internal combustion engine according to any one of clauses 3-3. 5 The process to be omitted when it is determined that the engine speed is equal to or higher than the predetermined speed is based on the value of the reference pulse signal of the operating parameter signal at the time of current input and the read value up to the time of input this time. 5. A method for processing and calculating operating parameter signals for an internal combustion engine according to any one of claims 1 to 4, wherein the current input value is corrected based on the current input value.