JP3331237B2 - Injection start section setting method for each cylinder of a multi-cylinder engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for setting an injection start section for each cylinder of a multi-cylinder engine in which one cycle of each cylinder is divided into eight sections and an injection start section is designated.

[0002]

2. Description of the Related Art In recent years, microcomputers have been introduced into vehicles such as automobiles, and it has become possible to control engines, power trains and the like with high accuracy. As a result, in the development of vehicle control systems, the software development of microcomputers has become a major player,
It is important to improve the efficiency of the processing on the control algorithm. In particular, in recent engine control systems, the control contents are complicated, and efficient utilization of the CPU is important in improving engine controllability.

Generally, the fuel injection start timing in the engine control system by the microcomputer is set by an interruption process at every predetermined crank angle. For example, in Japanese Patent Application Laid-Open No. SHO 61-160545, the number of crank pulses input at every constant crank angle is counted to detect the rotational angle position of the engine, and the injection start timing is determined based on the detected value (so-called angle control). Alternatively, an injection start timing is calculated based on an interval time measured between predetermined crank angles (so-called time control).

[0004]

By the way, when performing sequential control in a multi-cylinder engine, conventionally,
According to the instruction to start the injection several times before the start of the intake stroke, in the interrupt processing synchronized with the engine rotation, the current crank angle is calculated several times before the intake stroke, and the result is compared with the indicated value to compare the fuel value. The determination of whether to start the injection is repeated for all cylinders.

In an engine for controlling the injection end, the injection end timing is determined from the current engine speed.
The procedure for calculating the injection start timing back from the end timing is performed during the interrupt processing for each crank angle described above.

As a result, in the fuel injection control, the interrupt processing synchronized with the engine rotation becomes complicated and heavy, and if the sequential control is performed at a high rotation speed, other control processing is hindered. Could not do.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and reduces the load of interrupt processing executed in synchronization with engine rotation so that a multi-cylinder can obtain good controllability even at high rotation. It is an object of the present invention to provide a method for setting an injection start section for each cylinder of an engine.

[0008]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The present invention relates to a cylinder-specific crank indicating a cylinder and a crank position.
Parameterize the overall crank position variable that comprehensively represents the position section.
One cycle for each cylinder, the second half of the intake stroke,
First half of intake stroke, second half of exhaust stroke, first half of exhaust stroke, combustion stroke
8 in the second half, the first half of the combustion stroke, the second half of the compression stroke, and the first half of the compression stroke
Each cylinder is divided into sections and each section is represented by a unique numerical value.
Each injection start section table is provided, and the set injection start
The set time is set to a value that is executed at a preset time period.
Start interrupt of the above section by computer interrupt processing
From the input of the crank angle sensor indicating the angle
When the interval until the crank angle sensor signal indicating the rank angle is input
Between fuel injections until it becomes zero or negative.
The injection start section to be performed is specified, and the specified injection start section is specified.
Is set in the injection start section setting flag, and the
The engine rotation is synchronized by inputting the link angle sensor signal.
The current cylinder and current
And the crank position comprehensive variable representing the crank position
Referring to the injection start section table for the relevant cylinder,
Section and the above-mentioned injection
Specified by the variable set in the start section setting flag
Compared to the section with
The fuel injection start section is determined.

[0009]

According to the present invention, an injection start section is set for each cylinder.
Crank position by cylinder indicating cylinder and crank position
Parameterize the overall crank position variable that comprehensively represents the section
One cycle for each cylinder, the second half of the intake stroke,
The first half of the stroke, the second half of the exhaust stroke, the first half of the exhaust stroke, after the combustion stroke
8 sections: half, first half of combustion stroke, second half of compression stroke, first half of compression stroke
Between the cylinders, and this section is represented by a unique numerical value for each cylinder.
Is provided. And set
Executes the injection start set time at a preset time cycle
In the interrupt processing performed, the starting crank angle of the above section
From the crank angle sensor signal input indicating
Interval time until crank angle sensor signal indicating link angle
And then subtract until the value becomes zero or negative, and perform fuel injection.
To determine the injection start section, and the specified injection start section
Is set in the injection start section setting flag. Soshi
And engine rotation synchronization by inputting crank angle sensor signal
In the interrupt processing executed by the
The above crank position general variable representing the crank position
Referring to the injection start section table of the cylinder, the table
The interval indicated by the numerical value obtained by
Specified by the variable set in the start section setting flag
Compared to the section where
Determine the injection start section. Therefore, the engine rotation
In interrupt processing, refer to a table and refer to the table.
And the above-mentioned injection start section
The zone specified by the variable set in the configuration flag
Since the injection start section is determined by determining the match with the interval,
Interrupt that simplifies processing and executes in synchronization with engine rotation
The burden of processing is reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

The drawings relate to an embodiment of the present invention, and FIG. 1 is a flowchart showing a periodic interruption process every 0.5 ms.
FIG. 2 is a flow chart showing the class interrupt processing, and FIG.
4 to 7 are flowcharts showing a job execution subroutine, FIG. 8 is a flowchart showing a crank position calculation subroutine,
9 is a flowchart showing a CCAS / RCAS determination subroutine, FIGS. 10 and 11 are flowcharts showing a routine for calculating a fuel injection start timing, FIG. 12 is a flowchart showing an injection timer setting subroutine, FIGS.
4 is a flowchart showing an injection timer set macro 1 routine, FIGS. 15 and 16 are flowcharts showing an injection timer set macro 2 routine, FIG. 17 is an explanatory diagram showing a job execution state, and FIG. 18 is an explanatory diagram of a job flag. 1
9 is an explanatory diagram showing changes in the job execution flag and the overlap counter, FIG. 20 is an explanatory diagram of the system shift buffer, FIG. 21 is an explanatory diagram of the classen interval table, and FIG.
FIG. 23 is an explanatory diagram of a cylinder / crank position state map, FIG. 23 is a time chart of a crank position, a cam position and a crank position variable, an injection start section table, and a stroke order for each cylinder, FIG.
Is an explanatory diagram of an injection start section and an injection start section setting flag, FIG. 25 is a time chart showing an injection timer control, FIG. 26 is a schematic configuration diagram of an engine system, and FIG. 27 is a front view of a crank rotor and a crank angle sensor. 28 is a front view of a cam rotor and a cam angle sensor, and FIG. 29 is a circuit configuration diagram of an electronic control system.

In the engine control system of this embodiment, an engine system shown in FIG. 26 is controlled by an electronic control unit (ECU) 50 having a microcomputer shown in FIG. 29 as a core, and fuel injection control, ignition timing control and the like are performed. Will be The microcomputer of the ECU 50 is equipped with an operating system (OS) based on a new concept, and under the control of the OS, each job based on each control strategy is executed according to its priority level.

First, the configuration of the engine system will be described.

In FIG. 26, reference numeral 1 denotes an engine (in this embodiment, a horizontally opposed four-cylinder engine), which includes # 1 and # 3 cylinders on the right bank R side, and # 2 and # 3 on the left bank L side.
It has four cylinders. The intake port 2a of the cylinder head 2 provided in both left and right banks of the cylinder block 1a.
An intake manifold 3 is communicated with the intake manifold 3, and a throttle passage 5 is communicated upstream of the intake manifold 3 via an air chamber 4. An air cleaner 7 is mounted on the upstream side of the throttle passage 5 via an intake pipe 6, and the air cleaner 7 is communicated with an air intake chamber 8, which is an intake port for intake air.

An exhaust pipe 10 communicates with the exhaust port 2b via an exhaust manifold 9, and a catalytic converter 11 is interposed in the exhaust pipe 10 and communicates with a muffler 12. On the other hand, a throttle valve 5a is provided in the throttle passage 5, and an intercooler 13 is interposed in the intake pipe 6 immediately upstream of the throttle passage 5,
Further, a resonator chamber 14 is provided downstream of the air cleaner 7 in the intake pipe 6.

An idle speed control valve (IS) is connected to a bypass passage 15 which communicates the resonator chamber 14 with the intake manifold 3 and bypasses the upstream and downstream sides of the throttle valve 5a.
CV) 16 is interposed. Furthermore, this ISCV1
Immediately downstream of 6, a check valve 17 that opens when the intake pressure is negative and closes when the intake pressure becomes positive due to supercharging by the turbocharger 18 is interposed.

In the turbocharger 18, a compressor is provided downstream of the resonator chamber 14 of the intake pipe 6, and a turbine is provided in the exhaust pipe 10. Furthermore, a wastegate valve 19 is interposed at the turbine housing inlet of the turbocharger 18, and a wastegate valve operating actuator 20 is connected to the wastegate valve 19.

The wastegate valve actuating actuator 20 is divided into two chambers by a diaphragm, one of which forms a pressure chamber which communicates with a wastegate valve control duty solenoid valve 21, and the other of which forms the wastegate valve 19. A spring chamber containing a spring biased in the closing direction is formed.

The waste gate valve control duty solenoid valve 21 is interposed in a passage communicating between the resonator chamber 14 and the compressor of the intake pipe 6 downstream of the turbocharger 18, and a control output from the ECU 50. The pressure on the resonator chamber 14 side and the pressure on the downstream side of the compressor are adjusted in accordance with the duty ratio of the signal, and are supplied to the pressure chamber of the wastegate valve actuating actuator 20.

That is, the waste gate valve control duty solenoid valve 21 is controlled by the ECU 50, and the waste gate valve operation actuator 20 is controlled.
Is operated to adjust the exhaust gas relief by the wastegate valve 19, so that the supercharging pressure by the turbocharger 18 is controlled.

An absolute pressure sensor 22 is connected to the intake manifold 3 through a passage 23,
3, an intake pipe pressure / atmospheric pressure switching solenoid valve 24 for selectively communicating the absolute pressure sensor 22 with the intake manifold 3 or the atmosphere is provided.

Further, an injector 25 is located immediately upstream of each intake port 2a of each cylinder of the intake manifold 3.
In addition, an ignition plug 26a whose tip is exposed to the combustion chamber is attached to each cylinder of the cylinder head 2, and an igniter 27 is connected to an ignition coil 26b connected to the ignition plug 26a. I have.

The injector 25 has a fuel tank 2
Fuel is pressure-fed from an in-tank type fuel pump 29 provided in 8 via a fuel filter 30, and the pressure is regulated by a pressure regulator 31.

An intake air amount sensor 32 is disposed immediately downstream of the air cleaner 7 in the intake pipe 6, and a throttle sensor 33 having a throttle opening sensor 33a and an idle switch 33b built in the throttle valve 5a. Are connected.

Further, a knock sensor 34 is attached to the cylinder block 1a of the engine 1, and a cooling water temperature sensor 36 is exposed to a cooling water passage 35 communicating both left and right banks of the cylinder block 1a. O2 is added to the collecting part of the exhaust manifold 9
A sensor 37 is exposed.

A crank rotor 38 is axially mounted on a crankshaft 1b supported by the cylinder block 1a. A crank angle sensor 39 such as an electromagnetic pickup is provided on the outer periphery of the crank rotor 38. Further, a cam angle sensor 41 for discriminating cylinders, such as an electromagnetic pickup, is provided opposite the cam rotor 40 connected to the camshaft 1c of the engine 1. still,
The crank angle sensor 39 and the cam angle sensor 41
Is not limited to a magnetic sensor such as an electromagnetic pickup, but may be an optical sensor or the like.

As shown in FIG. 27, the crank rotor 38 has projections 38a, 38b, 38c formed on its outer periphery, and these projections 38a, 38b, 38c are connected to the cylinders (# 1, # 2 and # 2). 3, # 4) before compression top dead center (BTD
C) It is formed at the positions of θ1, θ2, θ3. In this embodiment, θ1 = 97 ° CA, θ2 = 65 ° CA,
θ3 = 10 ° CA.

Each protrusion of the crank rotor 38 is detected by the crank angle sensor 39. As shown in FIG. 23, BTDC 97 °, 65 °, and 10 ° CA crank angle signals (classen signals) are rotated by one-half engine revolution. Every (18
0 ° CA). Then, the input interval time of each signal is measured by a timer, and the engine speed is calculated. The protrusion 38b serves as a reference crank angle at the time of setting the ignition timing, and the protrusion 38c serves as a reference crank angle of the injection start timing at the start and a crank angle indicating a fixed ignition timing at the start.

As shown in FIG. 28, on the outer periphery of the cam rotor 40, protrusions 40a, 40b,
A projection 40a is formed at a position θ4 after the top dead center (ATDC) of compression of the # 3 and # 4 cylinders.
b is composed of three protrusions, and the first protrusion is A of the # 1 cylinder.
It is formed at the position of TDCθ5. Further, the protrusion 40
c is formed by two projections, and the first projection is A of the # 2 cylinder.
It is formed at the position of TCDθ6. In this embodiment, .theta.4 = 20 DEG CA, .theta.5 = 5 DEG CA, .theta.6 = 2.
0 ° CA.

When each of the protrusions of the cam rotor 40 is detected by the cam angle sensor 41, and the order of the combustion strokes of the cylinders is # 1, # 3, # 2, # 4, the order of the combustion strokes and Cylinder discrimination is performed based on a pattern of the detection signal of the cam angle sensor 41 and the value counted by the counter (see the time chart of FIG. 23).

On the other hand, as shown in FIG.
Is composed mainly of two computers, a main computer 51 for performing fuel injection control, ignition timing control, etc., and a dedicated sub-computer 52 for performing knock detection processing, and a constant voltage for supplying a predetermined stabilized power to each unit. The circuit 53 and various peripheral circuits are incorporated.

The constant voltage circuit 53 includes an ECU relay 54
, And a relay coil of the ECU relay 54 is connected to the battery 55 via an ignition switch 56.
The constant voltage circuit 53 is directly connected to the battery 55, and the fuel pump 29 is connected to the battery 55 via a relay contact of a fuel pump relay 57.

That is, the constant voltage circuit 53 supplies control power when the ignition switch 56 is turned on and the relay contact of the ECU relay 54 is closed, and the ignition switch 56 is turned off.
When power is supplied, supply power for backup.

The main computer 51 includes a CPU 5
8 (hereinafter, referred to as main CPU 58), ROM 59,
RAM 60, ignition switch 56 is OFF
The backup RAM 6 that is supplied with backup power from the constant voltage circuit 53 and retains data even when the
1. A microcomputer in which a counter / timer group 62, an SCI 63 which is a serial communication interface, and an I / O interface 64 are connected via a bus line 65.

The counter / timer group 62 includes various counters such as a free running counter, a cam angle counter for counting the input of a cam angle sensor (hereinafter, abbreviated as cam angle) signal, an injection timer, an ignition timer, and the like. A periodic interrupt timer for generating a periodic interrupt every 0.5 ms, a class time timer for measuring an input interval of a crank angle sensor (hereinafter abbreviated as classene) signal, a watchdog timer for monitoring a system abnormality, etc. These various timers are collectively referred to for convenience. In the main computer 51, various other software counters and timers are used.

Similarly to the main computer 51, the sub computer 52 includes a CPU 71 (hereinafter referred to as a sub CPU 71), a ROM 72, a RAM 73, a counter / timer group 74, an SCI 75, and an I / O interface 76. The main computer 51 and the sub-computer 52 are connected to each other via the SCIs 63 and 7.
5 are connected to each other by a serial communication line.

The input port of the I / O interface 64 of the main computer 51 includes an intake air amount sensor 32, a throttle opening sensor 33a, and a water temperature sensor 3 as input ports.
6. O2 sensor 37, absolute pressure sensor 22, vehicle speed sensor 4.
2, and the battery 55 is an 8-channel input A / D
Connected via a converter 66, the idle switch 33b, the crank angle sensor 39, the cam angle sensor 41
Are connected, and a starter switch 43 is connected to detect a start state.

In this embodiment, the A / D converter 66 uses inputs for seven channels, and the remaining one is used.
The channel is reserved.

An igniter 27 is connected to an output port of the I / O interface 64.
ISCV16, injector 2 via drive circuit 67
5. The relay coil of the fuel pump relay 57, the waste gate valve control duty solenoid valve 21, and the intake pipe pressure / atmospheric pressure switching solenoid valve 24 are connected.

On the other hand, the I / O of the subcomputer 52
The interface 76 has an input port to which the crank angle sensor 39 and the cam angle sensor 41 are connected.
A knock sensor 34 is connected via a / D converter 78, a frequency filter 79, and an amplifier 80. After the knock detection signal from the knock sensor 34 is amplified to a predetermined level by the amplifier 80, the frequency filter 79 A required frequency component is extracted by the A / D converter 78
Is converted into a digital signal and input.

The main computer 51 processes the detection signals from the sensors and calculates the fuel injection pulse width, ignition timing, and the like. That is, the intake air amount sensor 32
The amount of intake air is calculated from the output signal of, the amount of fuel injection corresponding to the amount of intake air is calculated based on various data stored in the RAM 60 and the backup RAM 61, and the ignition timing and the like are calculated.

Then, a drive pulse width signal corresponding to the above-mentioned fuel injection amount is output to the injector 25 of the corresponding cylinder at a predetermined timing via the drive circuit 67 to inject fuel, and the igniter 27 is output at a predetermined timing. To output an ignition signal to ignite the ignition plug 26a of the corresponding cylinder.

As a result, the air-fuel mixture supplied to the corresponding cylinder explodes and burns, and the oxygen concentration in the exhaust gas is detected by the O2 sensor 37 facing the collecting portion of the exhaust manifold 9, and the detection signal is shaped. After that, the main CPU 58 compares the air-fuel ratio with a reference value (slice level) to determine whether the air-fuel ratio state of the engine is rich or lean with respect to the target air-fuel ratio. Feedback control is performed so that

On the other hand, the sub-computer 52 sets a sample period of the signal from the knock sensor 34 based on the engine speed and the engine load, and A / D converts the signal from the knock sensor 34 at high speed in this sample period. Then, the vibration waveform is faithfully converted into digital data to determine whether knock has occurred.

The output port of the I / O interface 76 of the sub-computer 52 is connected to the input port of the I / O interface 64 of the main computer 51. It is output to the interface 76. When the main computer 51 outputs the knocking determination result from the sub-computer 52, the knocking data is read from the serial communication line via the SCI 63, and the ignition timing of the corresponding cylinder is immediately determined based on the knocking data. Delay and avoid knocking.

In such an engine control, the main computer 51 executes various programs for each item such as signal input processing from each sensor, engine speed calculation, intake air amount calculation, fuel injection amount calculation, and ignition timing calculation. Is efficiently executed under the control of one OS. The OS has various management functions for vehicle control and an internal strategy closely related to the management functions, and systematically combines various jobs.

The management functions of the OS include (1-1) job priority processing (1-2) support of divided files of each job according to section definitions (1-3) stack usage monitoring function (1-4) Monitoring function of abnormal interrupt operation (1-5) There are functions such as standard map and standard work memory settings that do not create unique restrictions for each job, which improves the development environment for control strategies and maximizes the limited CPU capacity. It is possible to achieve as much as possible the equal time interval processing that is the basis of digital control theory.

The processing at equal time intervals is based on periodic interruption every 0.5 ms, and is based on 2, 4, 10, 50, 250
There are provided five types of equally-spaced interrupt jobs for every ms, and a high-priority classa job (hereinafter simply referred to as a class job) which is immediately executed by a crank angle signal input as a process synchronized with the engine rotation. And a low priority classene job with a relatively low urgency that is interrupted by the input of a crank angle signal when there is no other job with a higher priority.

Each of these jobs is a class job>
In the order of 2 ms job> 4 ms job> 10 ms job> low priority class job> 50 ms job> 250 ms job, the priority levels of 7 to 1 are assigned from the higher side to the lower side, as shown in FIG. A low-speed job is divided and processed for a high-speed job, and multiple waiting processing for each job is performed.

The programs operating under the OS are arranged in order in each area for each function, and each function is named by a section declaration. Various strategy files (user-side files) working under the OS use, for each function, a section declaration having the same name as the OS, for example, in the development stage, for example, initial value setting processing, processing every 10 ms, background processing, and the like. Even if the processes and the like are described in separate files, when the files are linked, the same processes are collected in one continuous area and integrated with the OS to operate integrally.

The main section areas used on each strategy file side are: a variable declaration area; a self-file name; an automatic recording area when creating a file; a setting data area; a classen job area; a 2 ms job area; a 4 ms job area; Job area ○ Low priority classa job area ○ 50ms job area ○ 250ms job area ○ Initialization job area at reset ○ Initialization job area at stalling ○ Background job area ○ Program main area Program development and structured description of programs.

The above OS has the following internal strategies closely related to the management functions: (2-1) A / D conversion processing (2-2) Calculation of various information related to crank position (2-3) Debugging Simulation functions (engine rotation and A / D conversion) (2-4) Set ignition timer (2-5) Set injection timer, etc. In addition, various service routines related to these functions are provided. Prepared during the job.

Conventionally, such a function has been achieved at each job level. However, in this system,
When the fuel injection amount, ignition timing, and the like are set in each job on the user side based on the A / D conversion result, crank position information, engine speed, and the like, all of which are prepared on the OS side and processed on the OS side, The instruction value is set in the injection timer and the ignition timer by the OS.

Next, the function of the fuel injection control in the main computer 51 will be described with reference to the flowcharts shown in FIGS. Since the sub-computer 52 is a computer dedicated to knock detection processing, its operation will not be described.

First, the ignition switch 56 is turned on.
Then, when the system is turned on, a reset interrupt associated with the reset is activated, various initializations are performed, a periodic interrupt timer for activating a periodic interrupt every 0.5 ms is activated, and the crank angle sensor 3 is activated.
9 (BTDC 97 °, 65 °, 10 °)
Classen interruption started six times per engine revolution per CA) is permitted, and then the background job execution state is set.

Then, on this background job, a periodic interruption every 0.5 ms, and 6
The 7th-level job is prioritized by the first class interrupt. In these two interrupts, after executing their own processing, they jump to a common address and execute the job priority processing.

Note that the reset interrupt may be caused by a factor that does not occur in a normal state, such as when division by 0 is performed in an internal operation or when an infinite loop occurs.
Is activated.

First, the periodic interruption every 0.5 ms shown in FIG. 1 will be described. In this periodic interrupt, step S1
At 00, an OS work area is set, and at step S101,
When the watchdog timer is initialized, the process proceeds to step S102, and the P-RUN flag is set once every 20 times, that is, 10 times.
Invert every ms. The P-RUN flag is a flag for preventing the system from being automatically reset by a protection circuit (not shown). The P-RUN flag is used as long as the system operates normally and is inverted every predetermined time (every 10 ms). The operation of the circuit is blocked.

Then, the process proceeds to a step S103 to transfer the switch output. This switch output is the ON / OFF value of the bit written in the memory in each job. The output from the job is not output directly to the output port of the I / O interface 64, but is output to the memory every 0.5 ms on the OS side. Transfer the value to the output port.

Next, in step S104, an A / D conversion subroutine is executed to make various settings relating to A / D conversion, and in step S105, a job flag creation subroutine is executed to execute 2, 4, 10 , 50, and 250 ms, the job flag JB_FLG indicating each job interrupt request is created, and in step S106, A / D conversion is started.

In the A / D conversion, basically, the eight channel inputs of the A / D converter 66 are processed in a predetermined conversion order every 0.5 ms, and all the inputs are converted in a cycle of 4 ms. However, one specific channel is synchronized (with a time accuracy of 0.5 ms) at every crank angle of 90 ° in order to A / D convert the suction pipe pressure at which rotational pulsation occurs, and interrupts the conversion order. The processing is performed in the form of an ellipse, and the order of subsequent input is delayed by one.

When the engine speed is 3750 rpm or more, the input of the last order of the A / D conversion is completely stopped, and
At 500 rpm or more, the second to last input also stops, but the order of A / D conversion is relatively slow changes such as cooling water temperature, voltage, etc., with the fastest change in throttle opening, intake air amount, etc. Is set to be later,
In addition, since the last A / D conversion order is set to the crank synchronization input, there is no particular problem.

As shown in FIG. 18, the job flag JB_FLG assigns each bit of a 1-byte variable as a flag corresponding to each job, so that a plurality of job requests can be made simultaneously. I have. Bits 1 to 7 of this 1-byte variable correspond to priority levels 1 to 7, respectively, and represent a 250 ms job, a 50 ms job,
Allocated to flags of low priority classa job, 10 ms job, 4 ms job, 2 ms job, and class job. When a predetermined bit is set, a job interrupt request of a corresponding priority level is made. still,
Bit 0 is assigned to the background job flag and is not normally referenced.

Then, the job flag JB_FLG is created by the job flag creation subroutine in step S105, and after the A / D conversion is started in step S106, the process proceeds to step S107, where the job flag JB_FLG is processed. Check whether the bit to be set is set.

As a result, when no bit of the job flag JB_FLG is set, the interrupt is terminated because there is no request from any job, and the job flag JB_F
If any bit of the LG is set, the process proceeds to step S108, and there is no flag lower than the current level (a state in which a job of a predetermined priority level is being executed at the time of execution of this periodic interrupt). Find out what.

In step S108, when there is no flag below the current level, the process jumps to the job priority process shown in FIG. 3 indicated by the label WAR_JB. When there is a flag below the current level, in step S109, the level below the current level is reached. Is incremented by one.

The overlap counter OLC is a counter for storing job requests. One byte is assigned to each priority level, and the job flag JB_F
It is incremented when a job is requested by the LG, and decremented when the job ends. That is, by storing the job request by the counter, it is possible to cope with the multiplex request of the job.

Next, from step S109 to step S1
The process proceeds to step 10 to check whether there is a flag higher than the current level. If there is no flag higher than the current level, the process exits the routine and terminates the interrupt. If there is a flag higher than the current level, the job priority processing of the label WAR_JB is performed. Jump to

On the other hand, in contrast to the periodic interrupt every 0.5 ms, in the interrupt by the class shown in FIG.
In step S201, when the work area for the OS is set.
Then, a subroutine for calculating the crank position, which will be described later, is executed to calculate a crank position variable for determining the current crank position and the elapsed time of the engine half rotation, that is, the half rotation time, which is the sum of the latest three classen intervals. I do.

The above crank position variables are system variables prepared in the OS, and as shown in FIG.
The crank position for the # 4 cylinder is determined by the crank angle sensor 3
BTDC 97 °, 65 °, 10 by signal input from 9
Twelve states are classified according to ° CA, and the current crank position is represented.

That is, for each cylinder, a crank position information variable S_CC indicating the class input order by numerical values of 0, 1, and 2
AS, # 1 cylinder is 0, # 3 cylinder is 1, # 2 cylinder is 2, #
Cylinder information variable S_ indicating the combustion order of the cylinders, where four is three cylinders
RCAS and 3 of the total position variable S_ACAS which comprehensively represent the classen order and the cylinder order by numerical values from 0 to 11
The current crank position is represented by a variable, and 0 indicates that the crank position is normally determined with certainty.
The estimated state where the discrimination result is inconsistent and anxiety remains 1,
An error level S_ECAS in which the unknown state is set to 2 indicates the determination state of the crank position. In FIG. 23, S_, which indicates a system variable, is omitted.

Next, from step S201 to step S2
In step 02, it is checked whether the crank position determination has been normally completed or not determined in the subroutine for calculating the crank position by reading the code stored in the accumulator A (error code 1, normal end code 0). ).

When the value of the accumulator A is 1 and the crank position cannot be determined in step S202, the interrupt is terminated, the value of the accumulator A is 0, and the crank position is determined normally. If so, the process proceeds to step S203, and the engine stall flag is released.

The engine stall flag is a flag indicating that the engine is in an engine stall state. When the classen interval is 0.5 sec or more (about 30 rpm or less), an engine stall routine prepared for a 50 ms job is performed. , And the engine is cleared by this classen interrupt and the engine stall state is released.

Next, in step S204, an ignition timer setting subroutine is executed, and an ignition timer is set in accordance with an ignition schedule created based on an instruction value of ignition timing set on the user job side. The ignition schedule is a structural variable having dwell start time, dwell-on waiting time, dwell-off waiting time, and the like as members. A creation routine is prepared during a 10 ms job, and an ignition sequence is determined according to the ignition schedule.

Next, in step S205, an injection timer setting subroutine, which will be described later, is executed to set the injection time corresponding to the required fuel injection width for each cylinder set on the user job side.
It is calculated as an effective injection width per injection according to one injection or a plurality of injections, set to an injection timer, and proceeds to step S206.

In step S206, it is determined whether or not the current job level at which this class is executed is its own job level. If the current job level is its own job level, in steps S207 and S208, the class job is executed. ,
Low priority class job overlap counter OLC
Are incremented by one, and the interruption is terminated. If the current job level is not the level of the class job, it is checked in step S209 whether the current job level is equal to or higher than the level of the low priority class job.

If the current job level is equal to or higher than the low-priority classa job, the process proceeds from step S209 to step S210, where the overlap counter OLC of the low-priority classa job is incremented by one.
At 11, the job flag of the class job is set, and the process jumps to the job priority processing of the label WAR_JB.

On the other hand, if the current job level is not equal to or higher than the low-priority class job in step S209, the process proceeds from step S209 to step S212, and the job flag of the class job is set. The job flag is set, and the process jumps to the job priority processing for the label WAR_JB.

In the job priority process shown in FIG.
In S300, when the job level JB_LEV, which is a one-byte variable indicating the priority level of the job, is increased by one, step S3
The process proceeds to 01 to check whether a job flag corresponding to this priority level is set. If the job flag is not set, the process returns to step S300 to further increase the job level JB_LEV by one. The initial value is changed from 0 to 1, and the process proceeds to step S303.

In step S303, it is checked whether or not there is an upper job flag.
Returning to step S300, the above processing is repeated. If there is no higher job, the process proceeds to step S304, where the job execution flag JB_RUN is set.
At 05, the highest-level job is executed by a job execution subroutine described later.

The above-mentioned job execution flag JB_RUN is
This flag is set at the start of the execution of a job and cleared at the end of the job. With this flag, a job interrupted by a higher priority job can be identified during the processing.

For example, as shown in FIG. 19, JB_LE
If a 10 ms job with V = 4 is being executed and an interrupt request for a 2 ms job with JB_LEV = 6 is made, the processing of the 10 ms job is interrupted and the 2 ms job with higher priority is set to JB_RUN = 1 and OLC = 1 Is executed. During the processing of this 2 ms job, JB_
When an interrupt request of 4 ms job of LEV = 5 occurs,
The 4 ms job is set to JB_RUN = 0 and OLC = 1 and an interrupt is accepted, but is not executed and enters a standby state.

Thereafter, when the execution of the job by the job execution subroutine is completed, the process proceeds from step S305 to step S306, in which the overlap counter OLC is decremented by 1. In step S307, it is checked whether or not the overlap counter OLC has become zero. . As a result, if the overlap counter OLC has not become zero and there are multiple job interrupt requests at the same priority level, step S3
Returning to step 05, the job is repeatedly executed, and when the overlap counter OLC becomes zero, the process proceeds from step S307 to step S308 to clear the job execution flag JB_RUN.

Next, the flow advances to step S309 to lower the job level JB_LEV by one and shift to the next job level.
In step S310, it is checked whether or not the job level JB_LEV has become zero. And the job level JB_
When the LEV is zero, this interrupt is terminated, and when the job level JB_LEV is not zero, the step S3
Proceeding to 11, it is checked whether the overlap counter OLC is zero.

In step S311, when the overlap counter OLC is zero, there is no job request at this level. Therefore, the process returns from step S311 to step S309 to lower the job level JB_LEV by one and repeat the same processing. If the overlap counter OLC is not zero, the flow advances to step S312 to check whether the job execution flag JB_RUN is set at this job level.

In step S312, when the job execution flag JB_RUN is set, since the job was being executed before the interruption, the interruption is terminated, the process returns to the job before the interruption, and the job execution flag JB_RUN is set. If not, the flow returns to step S304 to execute the job at this level and repeat the same processing.

That is, in FIG. 19, JB_LEV
= 6 completed 2ms job, OLC = 0, JB_RU
When N = 0, the job level is reduced by one, and JB_
4 ms job with LEV = 5, JB_RUN = 0, OL
JB_RUN = 1 is set from the standby state of C = 1,
Be executed. Furthermore, when the 4 ms job is completed, JB
The processing shifts to _LEV = 4, and the processing of the 10 ms job interrupted by the 2 ms job and the 4 ms job is resumed from the state of JB_RUN = 1 (job execution).

As described above, the periodic interruption every 0.5 ms,
A job flag J that notifies the priority level and the execution timing of each job, using the class interrupt as the basic timing.
Since the B_FLG is created, equal time interval processing and engine rotation synchronization processing can be realized as accurately as possible, and each job can be processed efficiently. Further, a job flag JB_F updated for each interrupt serving as a basic timing
Regardless of the LG, the multiplexing request of the job is stored by the overlap counter OLC. Therefore, even if the processing time of a certain job is prolonged and the timing for executing the same job comes again, the processing is abandoned. Instead, the processing can be continued as far as possible.

Next, the job execution subroutine of FIGS. 4 to 7 will be described.

First, in step S500, the job flag JB
_FLG is checked to see if the job to be executed is not a casen job.
The process branches to label ALJ10, and in the case of a class job, the process proceeds to step S501 to check whether or not cylinder discrimination has been performed.

If the cylinder discrimination has not been performed, the routine does not go out of the routine and the job is not executed.
Proceeding to S502, it is checked whether or not it is in the multiplex waiting state by referring to the value of the overlap counter OLC.

In step S502, when the state is not the multiplex wait state, the process proceeds to step S503, in which the system variable S_ACAS (crank total position variable) calculated for each class interrupt is set as the user variable ACAS. Branching to step S504, the user variable ACA
S is incremented by 1, and the remainder obtained by dividing by 12 is taken as a new user variable ACAS.
The software is updated as 1, 2,..., 11, 0, 1,.

That is, the classen job and the low-priority classen job may be delayed by being interrupted by themselves or a high-priority job. However, the classen interrupt is executed exactly in synchronization with the crank angle sensor signal, and the system variable S
_ACAS is updated regardless of job delay.

Therefore, during the job, the system variable S_AC
If the user refers to the AS and obtains information related to the cylinder and the crank position, and tries to perform a job in accordance with the information, if the user himself is delayed by another job, the cylinder corresponding to his / her job is delayed. And information on the crank position cannot be known. For this reason, in a class job and a low-priority class job, the system variable S_ACAS for the OS is fetched as the user variable ACAS when the job is not in the multiplex wait state, and the user variable ACAS is updated each time a job is executed and a multiplex request is issued. In addition, the information relating to the cylinder and the crank position corresponding to itself is obtained so that appropriate processing is performed.

Thereafter, the process proceeds from step S503 or step S504 to step S505, where a work area for the job is set. In step S506, a level-zero interrupt is permitted. In step S507, the process proceeds to the section of a class job. Then, the process linked to the class job section is executed, and in step S508, the interruption is prohibited and the routine exits.

Next, in step S500, if the job to be executed is not a class job, the label AL
In step S510 of J10, it is checked whether the job is not a 2 ms job. If the job is a 2 ms job, a work area for the job is set in step S511. In step S512, a level zero interrupt is permitted. Go to section. Then, the job main body (a routine based on the control strategy on the user side or a service routine prepared on the OS side) linked to this section is executed, and in step S514, the interruption is prohibited and the routine exits.

On the other hand, if the job to be executed is not a 2 ms job at step S510, the process branches from step S510 to step S520 to check whether the job to be executed is a 4 ms job. If the job is not a 4 ms job, the process branches to the label ALJ30. If the job is a 4 ms job, the process proceeds to step S522 after setting the work area of the job in step S521. Note that this 4 ms job is A
This job is a / D conversion utilization job, and uses A / D conversion data via a system shift buffer SSHB described later.

In step S522, a level zero interrupt is permitted. Then, when the flow advances to step S523, the switch input is read, and in step S524, the section shifts to a 4 ms job section to execute the linked job body. Thereafter, when exiting from the section of the 4 ms job, the interruption is prohibited in step S525, and the process proceeds to step S526 to shift the system shift buffer SSHB and exit from the routine.

The system shift buffer SSHB is
As shown in FIG. 20, the head offset addresses 0, +8, +1 where the respective A / D conversion results of eight channels are stored.
Each memory of Nos. 6, +24, +32, +34, +36, and +38, and a one-word memory at the head offset address -2 where crank-synchronous A / D conversion results are stored every 4 ms, and 0.5 ms One A / D conversion result executed every time is stored in one word (2 bytes).

From the head offset address 0, 4
It is a stage shift memory, and A / D for every 90 ° CA
The conversion result is stored, and the latest four data (for one rotation) can be referred to from the job. The head offset addresses +32, +34, +36, and +38 are each 1
When a smoothing function is selected, a value obtained by weighted averaging of A / D conversion results is stored so that noise removal and accuracy can be improved. Data is available for slow jobs.

Each head offset address +8, +
From addresses 16 and +24, a 4-word memory is used.
It is used for a 4 ms job. Each of these memories stores the latest A / D conversion result in 4
The data is stored in the next word by the value of the overlap counter OLC of the ms job, and when the 4 ms job is executed, the data is read from the leading direction, and with the end of the job, the data of each subsequent word is sequentially shifted to the leading direction. Therefore, it is a FIFO buffer that is read from previously stored data.

That is, A / D conversion is accurately performed at a period of 4 ms by a periodic interrupt every 0.5 ms.
The ms job may be delayed by being interrupted by a high-priority job. Therefore, the FIFO buffer is used for the transfer of the A / D conversion, and +8 to +16 to +24 for a 4 ms job.
After referring to the data of each FIFO buffer at the address (1) to (5), the data of each FIFO buffer is sequentially shifted in step S526.

On the other hand, if the job to be executed is not a 4 ms job at step S520 but branches to label ALJ30, then at step S530, the job to be executed is
Check whether the job is a ms job, and if the job is a 10 ms job, set the work area of the job in step S531,
In step S532, if an interrupt of level zero is permitted, step S5
At 33, the process moves to the section of the 10 ms job, the job body is executed, and the interruption is prohibited at step S534 and the routine exits.

In the section of the 10 ms job, the OS provides a service routine for calculating the number of revolutions of the engine from the half rotation time, a service routine for creating the above-described ignition schedule, and the like.

If it is determined in step S530 that the job to be executed is not a 10 ms job, the flow branches to step S540 to check whether or not the job to be executed is a low priority class job. When the job is not the low priority classa job, the process branches from the step S540 to the label ALJ50. When the job to be executed is the low priority class job, the process proceeds from the step S540 to the step S541. Check if there is.

If the current state is not the multiplex wait state, the process proceeds from step S541 to step S542, where the system variable S_ACAS (crank total position variable) is set as a user variable ACAS, and the process proceeds to step S544.
In the multiplex wait state, the process branches from step S541 to step S543, and the user variable ACAS is incremented by one to 1
After taking the remainder divided by 2, the process proceeds to step S544.

In step S544, the work area of the job is set, and in step S545, the interrupt of level zero is permitted. In step S546, the process moves to the section of the low-priority classa job, and after executing the job body, the process proceeds to step S547.
To disable the interrupt and exit the routine.

Further, at the label ALJ50, the step
In step S550, it is determined whether the job to be executed is a 50 ms job. If the job is a 50 ms job, the process proceeds to step S551 to set a work area for the job, and then proceeds to step S552.

In step S552, when the interrupt of level zero is permitted, in step S553, the process proceeds to the section of the 50 ms job, and the engine stop processing routine prepared on the OS side is executed.
It executes an ignition timing retard routine for each cylinder, a fuel injection start timing calculation routine, and the like, and also executes a routine based on a control strategy on the user side. Then, after the end of the job, the interruption is prohibited in step S554, and the routine exits.

On the other hand, if the job to be executed in step S550 is not a 50 ms job, the flow branches to step S560 to set the work area of the job, permit interruption of level zero in step S561, and proceed to step S562.
After shifting to the section area of the 250 ms job and executing the job body, the interrupt is prohibited in step S563, and the routine exits.

In the job priority processing described above, it is necessary to always accurately grasp the crank position. For each classen interrupt, the crank position calculation subroutine shown in FIG. 8 is executed, and the crank position variable S_CCAS,
S_RCAS, S_ACAS, S_ECAS are calculated. In the following description, S_, which is a system variable, is omitted from the crank position variable.

In this crank position calculation subroutine,
First, in step S600, the lower two bytes of the classa timer are stored in the lower two bytes of the soft timer. The classa timer is a hardware timer provided in the ECU 50. In the present embodiment, the 16-bit timer is a maximum of 2
Although counting is possible up to 55 ms, a continuous area of 3 bytes is secured in the memory, the 2 bytes of the classen timer are transferred to the lower 2 bytes, and the 3rd byte is counted up by an interrupt generated by overflow of the classen timer. By doing so, it is used as a soft timer. As a result, the signal input interval time from the crank angle sensor 39 (hereinafter abbreviated as “classen interval”) is set to a maximum of 64 seconds (2
It is possible to count up to 55 ms x 256)
Without using a special hardware timer of 6 bits or more, it is possible to easily cope with an extremely long classen interval such as during cranking.

Next, when the flow advances to step S601, it is checked whether or not the classen interval is equal to or less than a set time. This setting time is
The time as the classen interval corresponding to the maximum engine speed is, for example, 0.3 ms. When the classen interval is equal to or less than the set time in step S601, a count error of the classen timer due to noise or the like is caused in step S602.
Then, the error code 1 is stored in the accumulator A, and the process exits the routine. If it is determined in step S601 that the classen interval is longer than the set time, the count of the classen timer is determined to be normal and the process proceeds to step S603.

In step S603, CCAS R
The crank position is determined by executing a CAS determination subroutine. In step S604, it is determined whether or not the error level ECAS is 2, that is, whether or not the cylinder determination is not performed such as during cranking. Research, ECAS
If = 2, the flow branches to step S605 to store the error code 1 in the accumulator A, and exits the routine.

On the other hand, in step S604, ECAS6042
In the case of, the process proceeds to step S606, and the third byte of the soft timer is set to 0. Then, the process proceeds to step S607 to determine whether or not the crank position information variable CCAS is 1, ie,
Current crank position is BTDC 65 ° CA to 10 ° CA
(See FIG. 23), and CCAS = 1
In step S607, the process jumps from step S607 to step S609. When CCAS ≠ 1, the process proceeds from step S607 to step S608 to increment the A / D conversion request by one.
Proceed to step S609.

This A / D conversion request is a flag-like variable for instructing crank synchronous A / D conversion at every crank angle of 90 ° CA, and takes a value of 0 or 1; Instructs synchronous A / D conversion. That is, as described above, one of the eight channels of A / D conversion is performed at every crank angle 90 ° CA, but when CCAS becomes 0 (BTDC 97 ° C.).
A) and when CCAS becomes 2 (BTDC 10 ° C
A), a crank synchronous A / D conversion request is set, and A / D conversion at every 90 ° crank angle (more precisely, every 87 °, 93 °) with respect to the A / D conversion order every 0.5 ms. Is interrupted.

Thereafter, in step S609, the total position variable ACAS is calculated by multiplying the cylinder information variable RCAS by 3 and adding the crank position information variable CCAS (ACAS = RCAS × 3 + CCAS).
Then, the soft timer is limited to 2 bytes, and if the classa timer overflows, the lower 2 bytes are F
The process advances to step S611 as FFF (255 ms).

In step S611, the total position variable ACAS
= 0, 1, 2,... 11 as subscripts TCAS [AC
AS] (array element), and in step S612, the crank position information variable CCAS =
Array MTCSX [CCAS] with subscripts 0, 1, 2
Store the classen interval data in (array element).

As shown in FIG. 21A, the array TCAS is a 12-word classen interval table storing classen interval data for two engine revolutions corresponding to ACAS = 0, 1, 2,... , The sequence MTCSX,
As shown in FIG. 6B, a three-word classen interval table in which three classen interval data corresponding to CCAS = 0, 1, and 2 are stored.

That is, the CCAS ·
The RCAS determination subroutine (details will be described later) and each information variable CCAS, RCAS, AC
AS is updated, for example, CCAS = 1, RCAS =
1. When ACAS = 4 is updated and the crank position is currently BTDC 65 ° to 10 ° CA of the # 3 cylinder, the # 3 cylinder BTDC of the # 3 cylinder is counted from the input of the class signal at the BTDC 97 ° CA measured by the classen timer. BTDC
At step S611, the time until classan signal input at 65 ° CA (classen interval data) is calculated by the total position variable AC.
AS is stored as a parameter at the address of ACAS = 3 in the array TCAS, and in step S612, the crank position information variable CCAS is stored as a parameter in the array MTCS.
X is stored at the address of CCAS = 0.

Therefore, the total position variable ACAS and the crank position information variable C
Each time the CAS is updated, the data in the arrays TCAS and MTCSX is sequentially updated. Therefore, by referring to the array TCAS, it is possible to know the change in the classen interval (change in rotational speed) at each crank position of each cylinder. It is possible to determine the presence or absence of a misfire in each cylinder, the combustion state, and the like, and to grasp the operation status of all cylinders. Also,
By referring to the array MTCSX, the latest classene interval can always be obtained, and the current driving situation can be quickly grasped.

Next, in step S613, the value of the error level ECAS is checked again. Here, since it is already confirmed in step S604 that ECAS ≠ 2, it is checked whether or not the error level ECAS is 1, that is, whether or not the determination of the crank position is an estimated state in which anxiety remains. .

If ECAS ≠ 1 (that is, ECAS = 0) in step S613 and the crank position has been determined with certainty, the process proceeds from step S613 to step S614, where the sum of the three latest classen interval data ( The sum of classen interval data stored in the array MTCSX) is calculated as a 3-byte half-rotation time MTCS18 (MTCS18 = ΣMTCSX). That is,
The half-rotation time MTCS18 is calculated every time the crank position information variable CCAS is updated every classan interrupt and the data in the array MTCSX is updated.
The latest data can always be obtained by taking the moving sum of the classen interval for each position of 65 ° and 10 ° CA.

On the other hand, in the above step S613, ECAS = 1
When it is in the estimated state where the determination of the crank position remains uneasy, the half rotation time MTCS1 is determined from the array MTCSX.
In step S615, a half rotation time estimation subroutine is executed to estimate the half rotation time MTCS18.

The estimation of the half rotation time MTCS 18 is to estimate the current half rotation time from the previous classen interval time. That is, as shown in FIG. 23, if the current crank position information variable CCAS is 1, the previous crank angle angle is 32 ° CA (BTDC 97 ° to 65 ° C.).
A), and from the crank angle angle and the previous classen interval data, the half rotation time MT is calculated based on the following equation.
Calculate CS18. MTCS18 = previous classen interval × 180/32 Also, when CCAS = 2, BT
From the angle 55 ° CA between DC 65 ° to 10 ° CA and the previous classen interval data, the previous classen interval × 180 /
The half rotation time MTCS18 is calculated by 55, and
When CCAS = 0, BTDC10 ゜ CA to ATD
Based on the angle 93 ° CA between C83 ° CA (BTDC 97 ° CA of the next cylinder) and the previous classen interval data, the half-rotation time MTC is calculated by the previous classen interval × 180/93.
S18 is calculated.

Then, in the above step S614, the half rotation time M
After calculating the TCS18 or after estimating the half-rotation time MTCS18 in step S615, the process proceeds to step S616, where the half-rotation time MTCS18 of 3 bytes is limited to 2 bytes and stored in a predetermined variable MTCSK. In step S617, this variable MTCSK is doubled to obtain a variable MT
The result is stored in CSK4, and in step S618, the normal end code 0 is stored in accumulator A, and the routine exits.

In the above-described job execution subroutine, the engine speed is calculated every 10 ms, and the engine speed is calculated from the reciprocal of the variable MTCSK in which the 3-byte half-rotation time MTCS18 is limited to 2 bytes.

More specifically, half the time 30 sec, which is a half of the unit time (1 min) of the number of revolutions per minute, is a half revolution time MT.
By dividing by CSK, 2 in units of 1 rpm
A variable NRPM in byte units, that is, the engine speed is calculated (NRPM = 30 sec / MTCSK), and this engine speed is used as one of the basic parameters in various control amount calculation processes.

Next, according to the flowchart shown in FIG. 9, step S603 of the above-described crank position calculation subroutine is performed.
Will be described.

In this subroutine, first, the Camcen counter is limited to 0 to 4 in step S800. Cam angle sensor 4 counted by this cam center counter
As shown in FIG. 23, the number of cam pulses from 1 (the number of cam pulses between classene signal inputs) is 0 to 0 in a normal state.
However, since there is a possibility that an abnormal count value of 4 or more may occur due to the influence of noise or the like,
The limit is set to four, and the abnormal state is represented by four.

Then, the flow advances to step S801 to determine a combination of 5 × 4 × 2 (the Camsen counter is 0 to 4 and 5) based on the (count value of) the Camsen counter, the cylinder information variable RCAS, and the crank position information variable CCAS. Type, cylinder information variable RCAS
CCHMA in which the state data is stored for four types 0 to 3 and two types when the crank position information variable CCAS is 0, 1 and 2.)
Read P.

This cylinder / crank position state map CCH
As shown in FIGS. 22 (a) and 22 (b), the MAP determines whether the crank position information variable CCAS is 0 or 1, and determines whether the crank position information variable CCAS is a change point of the cylinder information variable RCAS.
State data indicating whether the combination of the Camsen counter and the cylinder information variable RCAS may occur is stored as normal or abnormal, and whether the determination is OK or not is stored for all possible states of the CASCEN counter and the cylinder information variable RCAS. It is possible to evaluate the current state and know the next state to be taken.

The state data is 2-bit data, and the value of bit 0 indicates whether the state is determined or estimated, and the value of bit 1 indicates whether the state is normal or abnormal. The value of bit 0 is
As shown in FIG. 22, it is determined only when the Camcen counter is 2 or 3 (see the Camcen signal pattern shown in FIG. 23). It is inevitable. The value of bit 1 is normal when 0, abnormal when 1 and normal only when the Camcen counter is 3 or less and matches the combination of crank position variables shown in FIG. Is in an abnormal state.

For example, CCAS = 0 or 1, that is,
As can be seen from FIG. 23, the combination in which the Camsen counter is 0 and the cylinder information variable RCAS is 0 with respect to BTDC 97 ° to 10 ° CA of a certain cylinder is a state in which it is sufficient to estimate the crank position normally. , The cylinder shown in FIG.
State data of binary 01 (normal estimation) is stored in a corresponding area of the crank position state map CCHMAP.
Since the combination in which AS is 0 is clearly abnormal and can only be estimated, state data of 11 (abnormal estimation) is stored in the corresponding area of the cylinder / crank position state map CCHMAP in binary. .

Further, the combination of CCAS = 2, that is, the combination of the Camcen counter of 3 and the cylinder information variable RCAS of 0 for the BTDC of 10 ° CA to ATDC of 83 ° CA of a certain cylinder is the crank across the TDC of the # 1 cylinder. Since the position can be determined normally, the cylinder / crank position state map C
The state data of binary 00 (normally determined) is stored in the corresponding area of the CHMAP. Further, the combination in which the Camsen counter is 2 and the cylinder information variable RCAS is 0 is clearly abnormal, but the Camsen input is apparently abnormal. Since it is inevitable that there are two or more, the state data of 10 (abnormal) is stored in the corresponding area of the cylinder / crank position state map CCHMAP.

When the status data is read from the cylinder / crank position status map CCHMAP in step S801, the flow advances to step S802 to determine whether or not the error level ECAS is not 2, that is, the current status has not been determined by the cylinder. Check whether the state is unknown or not, ECAS = 2
In step S803, it is checked whether or not bit 0 of the status data read from the cylinder / crank position status map CCHMAP in step S803 is 0, that is, whether or not the status is determined. If the status is determined, the process proceeds to step S804. If the state is the estimation state, the routine exits from the routine and waits until the state is determined.

On the other hand, if ECAS ≠ 2 in step S802, the flow advances to step S804 to check whether the state is the estimated state, and to the processing after step S805 or the processing after step S812 according to the confirmed state or the estimated state. . When the process proceeds to step S804 in the determined state in step S803, the process proceeds to step S805 and subsequent steps.

First, the processing after step S805 will be described.
Because the cylinder is determined regardless of the abnormality,
As can be seen from the time chart of FIG. 23, since the current classane interrupt is an interrupt of BTDC 97 ° CA after three or two cam pulses are input, the crank position information variable CCAS is set to 0.

Then, the flow advances to step S806 to check whether or not the Camcen counter is not 3.
If not, that is, if the Camcen counter is 2, since the # 2 cylinder has been ignited, the cylinder information variable RCAS is set to 3 in step S807, and the process proceeds to step S809. If the Camcen counter is 3, the # 1 cylinder is Since the ignition has been performed, the cylinder information variable RCAS is set to 1 in step S808, and the process proceeds to step S809.

In step S809, state data is read again from the cylinder / crank position state map CCHMAP using the updated crank position information variable CCAS, cylinder information variable RCAS, and Camsen counter as parameters, and bit 1 of this state data is set to 1 , That is, whether it is in an abnormal state.

As a result, in step S809, when bit 1 of the status data is 1 and it is determined that the status is abnormal, the crank position information variable CCAS and the cylinder information variable RC
Assuming that the update result of the AS is an estimation that remains uneasy
In step S810, the error level ECAS is set to 1 and the routine is exited. When the bit 1 of the status data is 0 and the state is normal, the error level ECAS is set to 0 in step S811 and the routine exits.

On the other hand, in the processing after step S812, in step S812, the current crank position information variable CCAS (the crank position information variable CCAS calculated by the previous classen interrupt) is 2, that is, the changing point of the cylinder information variable RCAS. It is checked whether or not CCAS = 2. If CCAS = 2, the process proceeds from step S812 to step S813, where the cylinder information variable R
CAS is incremented by 1, and the crank position information variable CCAS is set to 0 in step S814, and the process proceeds to step S817.

On the other hand, in the above step S812, CCAS ≠ 2
In step S812, the process proceeds from step S812 to step S815 to check whether the Cam Seng counter is not 0. If the Cam Seng counter is not 0, the process branches to step S813. If the Cam Seng counter is 0, the process proceeds to step S816.
Increments the crank position information variable CCAS by 1, and proceeds to step S817.

In step S817, state data is read from the cylinder / crank position state map CCHMAP again using the updated crank position information variable CCAS, cylinder information variable RCAS, and Camsen counter as parameters, and it is determined whether an abnormal state is present. Check that bit 1 of the status data is 0
If the state is normal, the routine exits the routine without changing the current error level (ECAS = 0). If the bit 1 of the status data is 1 in step S817, indicating an abnormal state, the process proceeds to step S818, and the error level ECAS is determined as an update result of the crank position information variable CCAS and the cylinder information variable RCAS as an estimation that remains uneasy. Set to 1 and exit the routine.

As described above, the crank position variable CCA
S, RCAS, ACAS, and ECAS are used to grasp the ever-changing state of the crank position, and further, using the cylinder / crank position state map CCHMAP, to evaluate the current state and to know the next state to be taken. Therefore, the program can be greatly simplified as compared with the process based on normal condition judgment, and the memory capacity can be reduced, the processing speed can be improved, and the specification can be changed by improving the flexibility of the program. Can be flexibly dealt with.

Next, the fuel injection start timing calculation routine shown in FIGS. 10 and 11 will be described. This fuel injection start timing calculation routine is one of the 50 ms jobs executed in step S553 of the above-described job execution subroutine, and how many ms before the fuel injection is started based on 10 ° CA immediately before the intake stroke. Is set for all cylinders.

First, it is determined in step S1000 whether or not the engine is at the time of starting. If the engine is at the time of starting, the process proceeds to step S1001, the injection start delay time IJDELY is set to 0, and the injection start section setting flag IJTMGF is set to, for example, 2 times in step S1002. Set to injection and exit the subroutine.

The injection start delay time IJDELY is incorporated in a timer waiting time set by an injection timer set macro 2 to be described later, and starts the injection start section (BTDC).
Determines the number of milliseconds after the start of the injection from the 97 @ CA classa signal input (hereinafter abbreviated as "97 @ CA classa") or the BTDC 10 @ CA classa signal input (hereinafter abbreviated as "10 @ CA classa"). . Also, # 1 to # 4 are set by the injection start section setting flag IJTMGF.
The injection start section of the cylinder is specified. That is, this injection start section is stored in advance in the injection start section table IJnTBL (n = # 1, # 2, # 3, # 4) for each of the # 1 to # 4 cylinders. As shown in FIG. 23, each injection start section table IJnTBL (n = # 1, # 2, # 3, #
In 4), one cycle of cylinders # 1 to # 4 is divided into eight sections of 97 ° CA class and 10 ° CA class in accordance with the above-described crank total position variable ACAS, and each section is defined as bit 7 to bit 0. The injection start section is set by the above-mentioned injection start section setting flag IJTMGF as a 1-byte variable corresponding to. That is, in the present embodiment, each of the injection start sections of the injection start section table IJnTBL is set to 0 in the second half of the intake stroke, 1 in the first half, 2 in the second half of the exhaust stroke, and 3 in the first half.
The second half of the combustion stroke is defined as 4, the first half is defined as 5, the second half of the compression stroke is defined as 6, and the first half is defined as 7 immediately after the end of the intake stroke. However, the injection process is not performed in the injection start section 0.

Therefore, in step S1002, I
JTMGF = 2 is 00000 if represented by an 8-bit variable.
Since it is 010, fuel injection is started from the injection start section 1 (10 ° CA class) without any waiting time.

On the other hand, if it is determined in step S1000 that it is not the time of starting, and the flow branches to step S1003, it is determined whether the injection start set time IJTIME is zero, and IJTIM is determined.
If E = 0, return to step S1001 and return to step S100
Exit the routine via 1, S1002.

The injection start set time IJTIME is set by a control strategy on the user side.
The required injection width IJ is added to the injection start set time IJTIME.
By substituting SEIn (n = # 1, # 2, # 3, # 4), the injection end can be substantially fixed at BTDC10 ° CA immediately before the intake stroke. The injection end control can be performed by arbitrarily setting the injection start set time IJTIME.

Accordingly, it is conceivable to set IJTIME = 0 in the control strategy on the user side. In this case, the process returns from step S1003 to step S1001, and in step S1002, the injection start section 1 (10 ° CA class) Starts injection without waiting time.

In step S1003, IJTIMEＪ0
When the process proceeds to step S1004, this step S10
From 04 onwards, an injection start section and an injection start delay time IJDELY based on the injection start set time IJTIME are calculated.

That is, the injection start set time IJT
The IME is used for classifier intervals (BTDC97 for each injection start section).
° to 10 ° CA or BTDC 10 ° to ATDC 83 ° C
(Interval time between A and A) to sequentially specify the injection start section by subtracting the value until the value becomes zero or negative, and specify the number of milliseconds from the start of the specified injection start section (97 ° CA class or 10 ° CA class). Whether the fuel injection should be started later is set by the injection start delay time IJDELY.

First, in step S1004, the classifier interval is subtracted from the injection start set time IJTIME, and the value is stored in the accumulator A. In step S1005, it is determined whether the value of the accumulator A is positive, zero, or negative. , A ≦ 0, the process proceeds to step S1006, where the injection start delay time IJDELY is set by a two's complement of the value stored in the accumulator A (IJDELY = −A), and the injection start section setting flag IJTMGF is set to 4 in step S1007. Exit the routine. In this case, the injection start section is 2, and the injection start delay time I
Fuel injection is started after JDELY.

On the other hand, if it is determined in step S1005 that A> 0, the flow branches to step S1008, where the value of the accumulator A is set to a value obtained by subtracting the classen interval from the value stored in the accumulator A (A = (A-classen interval), the value of the accumulator A is referred to in step S1009, and if A ≦ 0, the process proceeds to step S1010, where the injection start delay time IJDELY is set by the two's complement of the value stored in the accumulator A ( IJDELY = -A). In step S1011, the injection start section setting flag IJTMGF is set to 8
To exit the routine. In this case, the injection start section is 3, and the fuel injection is started after the injection start delay time IJDELY from the immediately preceding 10 ° CA class.

On the other hand, if it is determined in step S1009 that A> 0, the flow branches to step S1012, and the value of the accumulator A is set to a value obtained by subtracting the classen interval from the value stored in the accumulator A (A = A), the value of the accumulator A is referred to in step S1013, and if A ≦ 0, the process proceeds to step S1014, where the injection start delay time IJDELY is set to 2 of the value of the accumulator A.
(IJDELY = -A), and step S101
At 5, the injection start section setting flag IJTMGF is set to 16, and the routine exits. In this case, the injection start section is 4, and the fuel injection is started after the injection start delay time IJDELY from the immediately preceding 97 ° CA class.

On the other hand, if it is determined in step S1013 that A> 0, the flow branches to step S1016, and the value of the accumulator A is set to a value obtained by subtracting the classen interval from the value stored in the accumulator A (A = A-classen interval), referring to the value stored in the accumulator A in step S1017, and if A ≦ 0, proceed to step S1018,
The injection start delay time IJDELY is set to the above accumulator A
(IJDELY = -A), and in step S1019, sets the injection start section setting flag IJTMGF to 3
The routine exits as step 2. In this case, the injection start section is 5, and the fuel injection is started after the injection start delay time IJDELY from the previous 10 ° CA class.

On the other hand, if it is determined in step S1017 that A> 0, the flow branches to step S1020, and the value of the accumulator A is set to a value obtained by subtracting the classen interval from the value stored in the accumulator A (A = A-classen interval), refer to the value stored in the accumulator A in step S1021, and if A ≦ 0, proceed to step S1022.
The injection start delay time IJDELY is set to the above accumulator A
(IJDELY = -A), and sets the injection start section setting flag IJTMGF to 6 in step S1023.
The routine exits as step 4. In this case, the injection start section is 6, and the fuel injection is started after the injection start delay time IJDELY from the 97 ° CA classen two before.

On the other hand, if it is determined in step S1021 that A> 0, the flow branches to step S1024, and the value of the accumulator A is set to a value obtained by subtracting the classen interval from the value stored in the accumulator A (A = A-classen interval), referring to the value stored in the accumulator A in step S1025, and if A ≦ 0, proceed to step S1026,
The injection start delay time IJDELY is set to the above accumulator A
(IJDELY = −)
A), in step S1027, the injection start section setting flag IJT
The routine exits with the MGF set to 128. In this case, the injection start section is 7, and the fuel injection is started after the injection start delay time IJDELY from the previous 10 ° CA classen.

On the other hand, if it is determined in step S1025 that A> 0, the flow branches to step S1028, where the injection start delay time IJDELY is set to 0, and in step S1029, the injection start section setting flag IJTMGF is set to 128, and the routine exits. In this case, the injection start section is 7 and the previous three 1
Fuel injection is started without waiting time from 0 ° CA class. That is, the fuel injection that is started from the injection start section 7 without any waiting time is the maximum injection amount.

For example, as shown in FIG. 24 (a), when the injection start section is set to 5 (IJTMGF = 32) based on the injection start set time IJTIME, the injection start delay time IJDELY after the injection start section 5 Fuel injection is started. This will be described with reference to the total position variable ACAS of FIG. 23. In the case of # 1 cylinder, ACAS = 2, #
ACAS = 5 for three cylinders, ACAS = 8 for # 2 cylinder,
ACAS = 11 for the # 4 cylinder.

In the above flowchart, the bit designation of the injection start section setting flag IJTMGF is set to one place per cylinder.
If a plurality of bits are specified and the fuel is injected multiple times during one cycle, for example, it is possible not only to promote the vaporization in the first injection and to totally adjust the air-fuel ratio in the last injection, As a result, it is possible to flexibly cope with an increase in the amount of acceleration or the like by adjusting the amount of injection later.

In this flowchart, since the injection start section is set every 50 msec, the load on the main CPU 58 does not increase even if the engine speed reaches a high speed such as 9000 to 10000 rpm. Injection end control becomes possible even in the rotation speed range.

FIG. 12 is an injection timer setting subroutine, which is executed in step S205 of the interrupt processing routine by the class shown in FIG. 2, and sets the injection timer for each injection start section.

First, at step S1100, the error level EC is set.
It is determined whether AS is 2. If ECAS = 2, the determination of the crank position is in an unknown state, so the subroutine is exited without performing the subsequent processing.
Proceeding to S1101, it is determined whether or not the crank position information variable CCAS is 1, and if CCAS = 1, it is determined that calculation is unnecessary and the routine exits. As shown in FIG. 23, when CCAS = 1, it is an interrupt of 65 ° CA class, and since the setting of the injection timer in the current injection start section has already been completed, the subroutine is immediately exited to reduce the processing load. On the other hand, in the case of CCAS ≠ 1, it is either the interruption of the 97 ° CA class or the interruption of the 10 ° CA class, which is the start of the injection start section. Set the width and injection start timing.

First, in steps S1102 to S1105, an injection timer set macro 1 to be described later is executed for all cylinders, and an injection width (hereinafter referred to as an “effective injection width”) TEIJAn (n = # 1, # 2, #
3, # 4) are set for all cylinders.

Then, in step S1106, the effective injection width TE set in each of steps S1102 to S1105 is set.
It is determined whether or not IJAn is all zero. If all are zero, the subroutine is exited because it is not necessary to reset the injection timer. In addition, at least one cylinder has TEIJAn ≠ 0
In the case of, the process proceeds to step S1107, in which all the injection timers are stopped, and during that time, the following steps S1108 to S1111 are performed.

In steps S1108 to S1111,
The injection timer set macro 2 described later is executed for all cylinders, and the injection time based on the effective injection width TEIJAn set by the injection timer set macro 1 is set for all cylinders.

Then, in step S1112, all the injection timers are restarted, and the process exits the subroutine.

In step S1107, when all the injection timers are stopped, the injection time is not measured, so that the fuel injection is continued in the cylinder during fuel injection, and the injection stop state is continued in the cylinder during injection stop. Is done. The injection time set in steps S1108 to S1112 takes into account the processing time corresponding to the time during which the injection timer is stopped.

The injection timer set macro 1 for each cylinder executed in steps S1102 to S1105 in the injection timer set subroutine is executed according to the flowchart shown in FIG. 13 and FIG. The program of the injection timer set macro 1 is based on the injection timer set routine of the # 1 cylinder, and is made into a macro so that it can be applied to the # 2 to # 4 cylinders.

First, in step S1200, the corresponding #n (n =
1, 2, 3, or 4) the current injection start section number of the cylinder
Based on the crank total position variable ACAS, a check is made with reference to the injection start section table IJnTBL (FIG. 23) of the #n cylinder, and it is determined in step S1201 whether the injection start section number is zero. When the injection start section is zero, the process proceeds to step S1202, and when the injection start section is not zero, the process proceeds to step S1210.

Since the injection start section 0 is in the latter half of the intake stroke and the injection processing is not performed, the initialization processing of the fuel injection is executed in steps S1202 to S1209 in preparation for the next fuel injection. First, in step S1202, the cumulative injection width TEIJBn of the #n cylinder is set to zero. In step S1203, it is determined whether there is a fuel cut request from the user side job. If there is no fuel cut request, the process proceeds to step S1204, where the fuel cut request is If there is, the process proceeds to step S1208.

It is determined that there is no fuel cut request and step S1
In step 204, it is determined whether the #n cylinder is in the fuel cut state with reference to the value of the fuel cut state flag PRCUT. If the fuel cut state is not in progress, the flow proceeds to step S1205. .

This fuel cut state flag PRCUT is #
Cylinders 1 to # 4 are represented in correspondence with the four bits of bit 0 to bit 3, and are set in the first routine when a fuel cut is requested by the user's job, and are also set after the fuel cut request is released. Cleared by the routine.

As described above, this fuel cut state flag PRCUT determines whether the bit corresponding to the #n cylinder is set in the injection start section 0, and there is no fuel cut request from the user side job, and No fuel is injected to the cylinder in which the fuel cut state flag PRCUT is set in the next cycle.

When it is determined that the fuel is not in the cut-off state and the process proceeds to step S1205, the injection processing is not performed in the injection start section 0, so that the effective injection width TEIJ of the #n cylinder concerned.
An is set to zero, and the injection timer set macro 1 for the #n cylinder is ended.

If the fuel cut state is determined from step S1204 and the flow advances to step S1206, there is no fuel cut request from the user side job, and the fuel cut state flag PRCUT is set. In order to inject the fuel equivalent to the adhesion correction amount once in the injection start section zero of the #n cylinder in preparation for the fuel cut recovery in the next cycle, the fuel adhesion correction amount TEFUCH set in the user-side job , The effective injection width TEIJAn of the #n cylinder is updated, and step S1207 is performed.
After the bit of the fuel cut state flag PRCUT corresponding to the #n cylinder is cleared, the injection timer set macro 1 for the #n cylinder is ended.

As a result, the adhesion correction for the fuel cut and the fuel cut recovery can be set for each cylinder.

If it is determined in step S1203 that there is a fuel cut request from the user side job, the fuel cut is requested in the injection start section 0 in which the injection process is not performed. Injection width TE
IJAn is cleared, the bit corresponding to the #n cylinder in the fuel cut state flag PRCUT is set in step S1209, and the injection timer set macro 1 for the #n cylinder is ended.

If it is determined in step S1201 that the current injection start section is other than zero, that is, it is within the injection processing area, normal injection processing is performed in step S1210 and subsequent steps. First, in step S1210, it is determined whether or not the #n cylinder is in the fuel cut state by referring to the value of the bit of the #n cylinder in the fuel cut state flag PRCUT. TEIJAn is set to zero, and the injection timer set macro 1 for the #n cylinder is ended.

On the other hand, if it is determined in step S1210 that the fuel is not in the fuel cut state, it is determined in step S1212 whether or not to inject fuel in a section after the current time.
Judgment is made with reference to the value of TMGF, and when it is judged that injection is to be performed also in a section after this, the process proceeds to step S1213,
Also, if it is determined that injection will not be performed in the section after now,
Proceed to step S1218.

Step S1212 is a step corresponding to a plurality of injections in one cycle. If there are two or more sections specified by bits 0 to 7 of the injection start section setting flag IJTMGF, for example, as shown in FIG. ), If IJTMGF = 32 + 4, section 5
And 2 are injection start sections. In the injection start section 5 (see FIG. 23), the injection is performed in a section after the present, so the process proceeds to step S1213. On the other hand, in the injection start section 2, no injection is performed in the section after the present. Therefore, the process proceeds to step S1218.

When the flow advances to step S1213, it is determined whether or not to perform the injection in the current section by the injection start section setting flag IJ.
Referring to the value of TMGF, the indicated value is determined in step S120.
Judgment is made based on whether it matches the current injection start section number searched at 0, and if injection is not performed in the current section, step S121
In step 4, the effective injection width TEIJAn is set to zero, and the injection timer set macro 1 for the #n cylinder is terminated.

On the other hand, if it is determined in step S1213 that the injection is to be performed in the current section, the flow advances to step S1215 to increase the cylinder-by-cylinder required injection width IJSEIn set by the user's job every 10 ms to the power of 2 n (n : 0, 1, 2, etc., which is set in advance or set according to the number of injections in one cycle) to obtain the injection amount per injection, and stores the value in the accumulator A. The effective injection width T of the #n cylinder is determined by the value stored in the accumulator A in S1216.
EIJAn is set, and in step S1217, the cumulative injection width TEIJBn is added to the value of the accumulator A, and the injection timer set macro 1 ends.

As shown in FIG. 24 (b), when there are two injection start sections, if the order n is set to 1, in the last injection start section, the latest required injection width for each cylinder IJSEIn
Is set to an effective injection width corresponding to 1/2 of the above.

Further, the steps S1212 to S12
Proceed to step 18 to determine whether to inject in the current section.
213, the injection start section setting flag IJTMGF
Is determined with reference to the value of, and when the injection is performed in the current section, the process proceeds to step S1219, and when the injection is not performed in the current section, the process proceeds to step S1223.

In step S1219, a value obtained by subtracting the cumulative injection width TEIJBn from the required injection width IJSEIn for each cylinder is stored in the accumulator A, and step S122 is performed.
When the value of the accumulator A is 0, the effective injection width TEIJ
Set An.

Next, in step S1221, the cumulative injection width TE
IJBn is set to the required injection width IJSEIn, and step S1
Proceed to 222. That is, the current section is the injection end section, and injection is not performed in the section after this. Therefore, in this routine, the cumulative injection width TEJBn is set to the required injection width IJ.
Make the same value as SEIn. As a result, for example, in the case of one injection in one cycle, TEIJBn = 0 and TEIJAn = IJSEIn. Then, when the routine is executed in the next injection start section, TEIJBn =
IJSEIn = 0.

Then, in step S1222, the injection wait setting flag FLG_IJ is set, and the injection timer set macro 1 ends. That is, this routine is the last injection in the cycle of the #n cylinder, and by setting the injection wait setting flag FLG_IJ, the injection end timing set by the injection timer set macro 2 described later is set to, for example, immediately before the intake stroke. Can be adjusted to 10 ° CA class.

On the other hand, steps S1218 to S12
In step 23, the accumulator A stores a value obtained by subtracting the cumulative injection width TEIJBn set in step S1221 from the required injection width IJSEIn for each cylinder.

In step S1224, the value of the accumulator A is referred to. If A <0, that is, if the required injection amount IJSEIn decreases due to a change in the operating condition, the process proceeds to step S1226, and A ≧ 0, that is, A ≧ 0 If the required injection amount IJSEIn has increased or has not changed, the process proceeds to step S1225. Since the fuel injection width is set every 10 ms in the user side job, if the required injection width IJSEIn read at the time of executing the next routine is different from the required injection width IJSEIn read at the time of executing the previous routine, the difference is obtained. Is increased or decreased, the effective injection width TEIJAn can always be set with the latest value, so that the follow-up performance to changes in operating conditions is improved.

Thereafter, the steps S1224 to S
Proceeding to 1225, the value of the accumulator A is compared with an allowable variation value of the injection width, for example, 0.5 ms, and A> 0.5 m
In the case of s, the process proceeds to step S1226, and in the case of A ≦ 0.5 ms, the process proceeds to step S1214, and the effective injection width TEIJA
n is set to zero, and the injection timer set macro 1 for the #n cylinder is ended.

When the process proceeds from step S1224 or step S1225 to step S1226, the effective injection width TEIJAn is set to the value of the accumulator A (a negative value in the case of step S1224), and the cumulative injection width TE is set in step S1227.
With IJBn set to the required injection width IJSEIn, the injection timer set macro 1 ends.

The injection timer set macro 2 in steps S1108 to S1111 in the injection timer set subroutine is executed according to the flowchart shown in FIG. 15 and FIG. The program of the injection timer set macro 2 is based on the timer set routine of the # 1 cylinder as a basic program, similarly to the flowchart showing the injection timer set macro 1, and the macro is set so that it can be applied to the # 2 to # 4 cylinders. It is a thing.

First, in step S1300, the fuel injection status set in the previous injection start section is determined from the state of the injection timer, and if injection is continuing during the current injection start section, the flow advances to step S1301 to wait for injection. When the state is continued, the process proceeds to step S1307, and when the injection is completed, the process proceeds to step S1312.

It is determined that the injection is continuing, and step S130 is performed.
When proceeding to 1, the current timer value of the stopped injection timer is
The positive or negative value effective injection width TEIJAn (ms) set by the injection timer set macro 1 of the #n cylinder is added, and the value is stored in the accumulator A. Therefore,
The value of the injection timer once set in the previous routine is corrected with the latest effective injection width TEIJAn set based on a change in the operating conditions thereafter.

Next, in step S1302, the processing time (time from the stop of the injection timer to the resetting) is subtracted from the value of the accumulator A, and this subtracted value is used in step S1302.
In S1303, a limit is set between two rotation times, which is the maximum injection amount of one cycle from zero (0 ≦ A <2 rotation times, so that when A is negative, A = 0), and step S1304.
Then, since the injection is currently being performed, the timer waiting time is set to 0, the reload value of the injection timer is set by the value of the accumulator A in step S1305, and the output pattern of the injection pulse corresponding to the reload value is set to the timer in step S1306. Then, the injection timer set macro 2 for the #n cylinder is terminated.

As a result, in the single injection, the effective injection width TEI set in the present section is the section after the injection section, and in the multiple injection, the section after the last injection section.
If JAn is longer than the value set in the previous section by 0.5 ms or more, the injection timer is extended, and if the effective injection width TEIJAn is reduced, the injection in the last injection section is The timer is shortened, and the total injection amount supplied to the cylinder during one intake stroke is adjusted.

On the other hand, if it is determined in step S1300 that the injection waiting state is continued, and the flow advances to step S1307, the timer reload value set in the injection timer is set to the positive or negative value set in the present section. Value effective injection width T
EIJAn is added, and the value is stored in accumulator A. In step S1308, the value of accumulator A is limited from zero to two rotation times, which is the maximum injection amount in one cycle (0 ≦ A <2 rotation times). ), Step S1309
In step S1310, the timer wait time is set to 0 to immediately perform injection, the timer reload value is set to the value stored in the accumulator A, and the output pattern of the injection pulse corresponding to the timer reload value is set in step S1311. To terminate the injection timer set macro 2 for the #n cylinder.

The timer waiting time is set in step S1325, which will be described later, in order to adjust the injection end timing. However, the waiting time set in the previous injection start section is also used in the current injection start section. If the time is still measured, the timer wait time is abnormally long, so the value is set to zero in step S1309, the injection is started immediately in the current injection start section, and the injection amount supplied during one intake stroke is adjusted. .

Also, in step S1300, it is determined that the injection in the previous injection start section has already been completed, and when the flow proceeds to step S1312, the effective injection width TEI is stored in accumulator A.
JAn is stored. In step S1313, it is determined whether the value of the accumulator A is positive, negative, or zero. If A ≦ 0, the process proceeds to step S1314. If A> 0, the process proceeds to step S13.
Branch to 18.

In step S1314, the effective injection width TEIJ
In order to end the injection in one cycle since An has not increased, the injection wait setting flag FLG_IJ is cleared, the timer wait time is set to zero in step S1315, the reload value of the injection timer is set to zero in step S1316, and step S1317 To set the output pattern to zero and terminate the injection timer set macro 2 for the #n cylinder.

Further, in the above step S1313, the effective injection width T
If EIJAn is positive, in step S1318, the accumulator A is provided with the dead time TSIN for each cylinder set by another control strategy to compensate for the increase in the injection amount.
Jn (n = # 1, # 2, # 3, # 4) is added, and in step S1319, if the value stored in the accumulator A exceeds the two rotation time, which is the maximum injection amount in one cycle, It is limited to two rotation times (A <2 rotation time), and in step S1320, it is determined whether or not the injection is in the injection waiting state by referring to the value of the injection waiting setting flag FLG_IJ. Flag FLG
If _IJ is cleared, the process proceeds to step S1321, the timer wait time is set to 0 in order to immediately inject the increased amount, and the timer reload value is set to the value of the accumulator A (TEIJAn + TSINJn) in step S1322, and step S1323 Then, the output pattern of the injection pulse corresponding to the timer reload value is set in the injection timer, and the injection timer set macro 2 for the #n cylinder is terminated.

On the other hand, if it is determined in step S1320 that the injection is in the injection waiting state and the flow advances to step S1324, the injection waiting setting flag FLG_IJ is cleared, and in step S1325,
The timer wait time is set by the injection start delay time IJDELY set in the injection start timing calculation routine, and step
In step S1326, the timer reload value is set by the value of the accumulator A. In step S1327, the output pattern of the injection pulse corresponding to the timer reload value is set in the injection timer, and the injection timer set macro 2 for the #n cylinder is ended. . As a result, fuel injection is started after a predetermined timer waiting time (IJDELY) from the start of the injection start section.

As a result, as shown in FIG. 25, the number of injections in one cycle is set to four, three, and two by the bit designation by the injection start section setting flag IJTMGF set in the fuel injection start timing calculation routine. And so on. Further, in the multiple injections, the effective injection width other than the last injection is set to 1/4, 1/2, or 1 of the required injection width.
/ 1, etc., and can be adjusted so that the total of the injection widths in one cycle in the final injection becomes the latest required injection width. Furthermore, if the injection does not end within the injection start section of the final injection, the injection timer is extended, and if the effective injection width is reduced, the injection timer is shortened to follow up during transients such as acceleration increase. To improve.

FIG. 25B shows four injections (IJT).
(MGF = 128 + 32 + 8 + 2), the effective injection width per injection is 1/4 of the required injection width, and FIG. 4C shows three injections (IJTMGF = 32 + 8 + 2), and the effective injection width per injection is required. 1/4 of the injection width, and FIG.
In the first injection (IJTMGF = 16 + 2), the effective injection width per injection is 1/1 of the required injection width, and FIG.
This is an example in which the effective injection width per one injection is set to 1/1 of the required injection width in two injections (IJTMGF = 4 + 2).

The embodiment of the present invention has been described above. However, the present invention is not limited to this.
Further, the present invention can be applied to engines other than the horizontally opposed engine.

[0211]

As described above, according to the present invention, one cycle of each cylinder of a multi-cylinder engine is divided into eight sections.
In the interrupt processing synchronized with the rotation, it is determined whether the current section is the designated injection start section and whether injection should be started is determined, so that the load of the interrupt processing is reduced,
Even when the engine is running at a high speed, there is an excellent effect such that a margin is provided for the processing, and good control of fuel injection can be obtained without hindering other control processing.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a periodic interrupt process every 0.5 ms.

FIG. 2 is a flowchart showing a class interrupt process;

FIG. 3 is a flowchart illustrating job priority processing.

FIG. 4 is a flowchart showing a job execution subroutine.

FIG. 5

FIG. 6

FIG. 7

FIG. 8 is a flowchart showing a crank position calculation subroutine.

FIG. 9 is a flowchart showing a CCAS / RCAS determination subroutine.

FIG. 10 is a flowchart showing a fuel injection start timing calculation routine.

FIG. 11

FIG. 12 is a flowchart showing an injection timer setting subroutine.

FIG. 13 is a flowchart showing an injection timer set macro 1 routine;

FIG. 14

FIG. 15 is a flowchart showing an injection timer set macro 2 routine;

FIG. 16

FIG. 17 is an explanatory diagram illustrating a job execution state.

FIG. 18 is an explanatory diagram of a job flag.

FIG. 19 is an explanatory diagram showing changes in a job execution flag and an overlap counter.

FIG. 20 is an explanatory diagram of a system shift buffer.

FIG. 21 is an explanatory diagram of a classen interval table.

FIG. 22 is an explanatory diagram of a cylinder / crank position state map.

FIG. 23 is a time chart of a crank position, a cam position and a crank position variable, an injection start section table, and a stroke order for each cylinder.

FIG. 24 is an explanatory diagram of an injection start section and an injection start section setting flag.

FIG. 25 is a time chart showing injection timer control.

FIG. 26 is a schematic configuration diagram of an engine system.

FIG. 27 is a front view of a crank rotor and a crank angle sensor.

FIG. 28 is a front view of a cam rotor and a cam angle sensor.

FIG. 29 is a circuit configuration diagram of an electronic control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 25 ... Injector 39 ... Crank angle sensor 41 ... Cam angle sensor 50 ... Electronic control unit ACAS ... Crank total position variable IJnTBL ... Injection start section table IJTMGF ... Injection start section setting flag

Claims (1)

(57) [Claims] 1. A cylinder-specific crank indicating a cylinder and a crank position.
Parameter of the overall crank position that comprehensively represents the
One cycle for each cylinder as a meter after the intake stroke
Half, first half of intake stroke, second half of exhaust stroke, first half of exhaust stroke, combustion
Second half of the stroke, first half of the combustion stroke, second half of the compression stroke, first half of the compression stroke
Are divided into eight sections, and each section is represented by a unique numerical value.
An injection start section table is provided for each cylinder, and the set injection start set time is set to a preset time.
The computer interrupt processing executed periodically
Crank angle sensor signal input indicating the starting crank angle of the section
From the crank angle sensor signal indicating the end crank angle of the section.
Decreases to zero or negative in the interval time until signal input
Calculation to determine an injection start section for performing fuel injection, and
Of the injection start section setting flag
And set the engine rotation synchronously by inputting the crank angle sensor signal.
Computer interrupt processing that is executed
The above crank position comprehensive variable representing cylinder and crank position
Referring to the injection start section table of the corresponding cylinder,
The interval represented by the numerical value obtained by referring to the table and the above
Specified by the variable set in the injection start section setting flag
Compared to the section that is
Multi-cylinder characterized by determining a fuel injection start section
How to set the injection start section for each cylinder of the engine.