JPS632027B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an engine ignition timing control method. The engine has a throttle valve that controls the amount of intake air drawn into its combustion chamber, and the amount of intake air is controlled by the opening degree of the throttle valve. The control state of the intake air amount is detected by a pressure sensor that measures the intake manifold pressure, a flow rate sensor that measures the air flow rate, a throttle opening sensor that outputs a signal according to the throttle valve position, and the like. It is known that the fuel supply amount and ignition position are generally controlled based on the outputs of these sensors and engine speed information. In recent years, microcomputers have come to be used for engine control, and the control status of the intake air amount is input to the microcomputer as input information.
Based on this information, it has become possible to control the engine's ignition timing. Since microcomputers have memory, they have the advantage of being able to store more complex characteristics than conventional control based on analog circuits, which greatly improves control accuracy. As a result, the ignition position can be controlled with higher accuracy and over a wider range in accordance with the control state of the intake air amount. Furthermore, since the calculation processing speed is fast, the responsiveness to the control state of the intake air amount is also very fast. For example, this technology
It is disclosed in Publication No. 152716. These points make it possible to achieve higher engine output and faster engine response in response to changes in the amount of intake air. However, this has resulted in a sudden change in the torque of the engine's output shaft in response to rapid changes in the amount of intake air, which has brought about both great advantages and disadvantages. The problem with this is that the torque from the engine changes too faithfully and with a high response to commands from the driver, such as pressing the accelerator pedal, so if the driver is inexperienced, the commands due to his inexperience may suddenly change. A sudden change in the accelerator pedal, for example, will faithfully appear as a change in engine torque. This impairs smooth driving and makes driving that much more difficult. An object of the present invention is to provide an ignition timing control method for an engine that enables smooth operation. In the present invention, data on the ignition position obtained based on the control state of the intake air amount is used as the target value of the ignition position, and the ignition position where the previous ignition is actually ignited is brought closer to the target value by a certain predetermined value. is set as the new ignition position, and ignition is performed according to this new ignition position.
This suppresses unnecessary sudden fluctuations in torque due to inexperience of the driver. Furthermore, the embodiments described below also have the following features. In other words, conventional ignition position calculations are all performed in synchronization with engine rotation, and therefore, if engine rotational speed frequently fluctuates due to engine torque fluctuations, the amount of processing required of the computer will frequently fluctuate. For this reason, the processing capacity for engine control of the entire computer processing is unstable, and control accuracy is reduced. In other words, it is necessary to lower the evaluation of a computer's processing power and sacrifice its processing power to some extent from the beginning. In order to eliminate this problem, it is necessary to execute the ignition timing control program at regular intervals as much as possible. For this reason, there is a program executed to determine the ignition position according to the control state of intake air to the engine, and a program executed to correct the above program output by inputting the previous ignition timing as well. The program is separated into at least two types, and the former program is executed at regular intervals. By executing the latter program in synchronization with the engine's output shaft, the number of programs that are executed in synchronization with engine rotation can be minimized, and as a result, fluctuations in the amount of processing required of the computer can be reduced. . This will be explained below using examples. In this embodiment, a pressure sensor is used as a sensor for detecting the control state of the intake air amount of the engine, but as described above, an air flow rate sensor or a sensor for detecting the opening state of a throttle valve can also be used. FIG. 1 is a system diagram of the entire engine system. First, the flow of intake air guided to the cylinders of the engine will be explained. Air cleaner 2
The introduced air is compressed by a compressor 8 which is rotated at high speed by a turbine 6 of a turbocharger 4. Compressed air is introduced into each cylinder of the engine via a throttle valve 10 or an air bypass valve 14 provided in a throttle chamber. In FIG. 1, only one cylinder is representatively shown. This cylinder is provided with an intake valve 16.
When valve 6 is opened, a mixture consisting of air and fuel, which will be described later, is introduced. The throttle valve 10 is mechanically interlocked with an accelerator pedal 12 controlled by the driver, and the opening degree of the throttle valve is determined according to the amount of depression of the accelerator pedal. As a result, air resistance is controlled and the amount of air introduced into the cylinder is controlled. Next, the fuel supply system will be explained. fuel tank 2
Fuel is led from 0 to a fuel pump 24 via a filter 22, and the fuel pressurized by the fuel pump 24 is controlled by a fuel pressure control valve 26 so as to be maintained at a constant pressure with respect to the intake manifold pressure.
Fuel is introduced into the injection valve 28 at a pressure controlled by the fuel pressure control valve 26, and the injection valve is opened by an output pulse generated by the control unit 30, and fuel is supplied into the intake manifold. The fuel supplied into the intake manifold forms a mixture with intake air and is introduced into the cylinder via the intake valve 16. Next, the ignition system will be explained. The other end of the ignition coil, which is connected to the battery 40 via a key switch 42, is connected to the control unit 30. A power transistor provided in the control unit 30 supplies a charging current for charging the ignition coil with energy. Next, the charging current is cut off to generate a high voltage in the secondary coil of the ignition coil 44, and the high voltage is supplied to the spark plug 50 provided in each cylinder via the distributor 46. . The distributor 46 rotates in mechanical conjunction with an output shaft to which rotational force is applied by a piston 48 in the cylinder. The air-fuel mixture introduced into the cylinder is compressed by the piston 48, and combustion is started by the spark energy from the spark plug 50. The heat energy generated by the combustion of the air-fuel mixture is converted into mechanical energy, which is output through the output shaft of the engine. Next, the exhaust system will be explained. Combustion gas within the cylinder is led to the exhaust pipe 52 via an exhaust valve (not shown), causing the turbine 6 to rotate. It is then discharged to the atmosphere via the catalyst unit 54 and muffler 56. Note that the turbine 6 is provided with a bypass passage 60, and by controlling the opening of the bypass passage with a diaphragm 58, the turbine 6
The rotation speed is adjusted. Also, there is an EGR valve 62 between the exhaust pipe and intake manifold.
is provided, and exhaust gas is guided to the intake system. Explain the starter system. A starter motor 64 is connected to the output shaft of the engine as necessary. When the starter switch 66 is turned on, the starter motor is excited, and at the same time, the pinion provided on the starter shaft is coupled to the flywheel provided on the output shaft of the engine, thereby driving the pistons of the engine. This action converts thermal energy into mechanical energy within the engine's cylinders, and the engine uses this newly generated energy to move the output shaft. This causes the engine to become self-running, completing the starting operation. Next, the sensors for engine control will be explained. The control unit 30 has a knock sensor 7 as an input signal representing the status of each system of the engine.
2. Water temperature sensor 74, throttle switch 76,
The outputs of the pressure sensor 78, crank angle sensor 80, exhaust gas sensor 82, and starter switch 66 are input. Knock sensor 82 generates a pulse in response to a knocking condition in a known manner. Water temperature sensor 74 transmits an analog voltage to unit 30 based on the engine cooling water temperature. The throttle switch 76 outputs an "H" level output when the throttle is fully closed, and in other conditions,
Outputs “L” level output. The pressure sensor 78 outputs a voltage corresponding to the pressure above the throttle valve in the intake manifold. As is already known, the crank angle sensor 80 has a disc with two types of slits cut into it, which is fixed to the shaft of a distributor that rotates in synchronization with the output shaft of the engine, and the rotation of the disc is detected by a photocoupler. Ru. This generates a reference angle pulse (hereinafter referred to as REF pulse) and a unit rotation angle pulse (hereinafter referred to as POS pulse) in accordance with the rotation of the output shaft of the engine. In a four-cylinder engine, a reference angle (REF) pulse is generated every 90 degrees, and a unit (POS) pulse is generated, for example, every 2 degrees. Next, the control unit will be explained. FIG. 2 is a detailed circuit configuration diagram of the control unit 30 shown in FIG.
2 and read-only memory 104 (hereinafter referred to as ROM)
It is written as ) and random access memory 106
(hereinafter referred to as RAM) and an input/output circuit 108. The above CPU102 is ROM104
The input data from the input/output circuit 108 is operated on using various programs stored in the internal memory, and the operation results are returned to the input/output circuit 108 again. RAM 106 is used for intermediate storage necessary for these operations. CPU102, ROM104, RAM106,
Various types of data are exchanged between the input/output circuits 108 via a bus line 110 consisting of a data bus, a control bus, and an address bus. The input/output circuit 108 includes a first analog-digital converter ADC1 (hereinafter referred to as ADC1) and a second analog-digital converter ADC2.
(hereinafter referred to as ADC2), angle signal processing circuit 140 for detecting engine rotational speed, and discrete input/output circuit DIO (hereinafter referred to as DIO) for inputting and outputting 1-bit information. The ADC1 includes a battery voltage detection sensor 122 (hereinafter referred to as VBS) and a cooling water temperature sensor 74 (hereinafter referred to as VBS).
(hereinafter referred to as TWS) and atmospheric temperature sensor 124 (hereinafter referred to as TAS)
), the adjustment voltage generator 126 (hereinafter referred to as VRS), and the throttle angle sensor 128 (hereinafter referred to as θTHS)
) and exhaust gas sensor 82 (hereinafter referred to as λS)
The output from the multiplexer 130 (hereinafter referred to as MPX
MPX (multiplexer) 1
30 selects one of these and converts it into an analog/digital conversion circuit 132 (hereinafter referred to as ADC).
Enter. The digital value that is the output of the ADC 132 is held in a register 134 (hereinafter referred to as REG). In addition, the pressure sensor 78 (hereinafter referred to as VCS)
The signal is input to the ADC2, converted into digital data via an analog-to-digital conversion circuit 136 (hereinafter referred to as ADC), and set in a register 138 (hereinafter referred to as REG). From the angle sensor 80 (hereinafter referred to as ANGS)
REF (a signal indicating a reference crank angle, for example, 180 degrees crank angle) and POS (a signal indicating a unit angle, for example, 2 degrees crank angle) are output, and the angle signal processing circuit 1
40, where a measurement of engine speed is made. The DIO (discrete input/output circuit) includes a throttle switch 76 (hereinafter referred to as TH-SW) and a top gear switch 142 (hereinafter referred to as TH-SW).
TOP-SW) and starter switch 66
(hereinafter referred to as START-SW) is input. The details of this DIO will be described later using FIG. 28. Next, the pulse output circuit and control target based on the calculation results of the CPU will be explained. Control circuit 152 (denoted as INJC) for controlling the injection valve 28
is a circuit that converts the digital value of the calculation result into a pulse output. Therefore, a pulse having a pulse width corresponding to the fuel injection amount is generated by INJC152,
It is applied to the injector 28 via the AND gate 154. For details of INJC152, please refer to Parts 29-3.
This will be explained later using Figure 0. The ignition pulse generation circuit 156 (hereinafter referred to as IGNC) has a register (hereinafter referred to as ADV) for setting the ignition timing and a register (hereinafter referred to as DWL) for setting the primary current energization start time of the ignition coil.
These data are set by the CPU. AND gates 158, 16 to ignition 162 for generating pulses based on the set data and controlling the primary current of ignition coil 44 in FIG.
Apply this pulse through 0. This IGNC15
6 will be described later using FIG. 27. The opening rate of the bypass valve 14 is determined by the control circuit (hereinafter referred to as
ISCC) 164 via an AND gate 166.
ISCC164 is a register that sets the pulse width.
Register to set ISCD and repeat pulse period
Has ISCP. The detailed circuit of this ISCC will be explained with reference to FIG. Controls the EGR control valve 62 shown in FIG.
EGR amount control pulse generation circuit 168 (hereinafter referred to as EGRC)
) has a register EGRD for setting a value representing the pulse duty and a register EGRP for setting a value representing the pulse repetition period. This EGRC output pulse is AND gate 1
70 to the EGR control valve 62. This EGRC circuit will also be described later using FIG. Further, the 1-bit input/output signal is controlled by a circuit DIO (discrete input/output circuit). The input signal is TH-SW from the throttle switch.
Signal, TOP from top gear switch 142
SW signal, START from starter switch 66
- There is a SW signal. Further, the output signal includes a pulse output signal for driving the fuel pump 24. This DIO is provided with a register DDR 192 for determining whether a terminal is used as an input terminal or an output terminal, and a register DOUT 194 for latching output data. The mode register 172 is a register (hereinafter referred to as MOD) that holds instructions for commanding various states inside the input/output circuit 108. For example, by setting an instruction to this mode register 172,
AND gates 154, 158, 166, and 170 are all activated or deactivated. By setting the command in the mode register 172 in this way, INJC152 and IGNC1
56, ISCC164, and EGRC168 output stop and start can be controlled. Next, the programs stored in the ROM 104 will be explained. FIG. 3 shows a program system for the control circuit of FIG. When power supply voltage is applied to CPU 102 by key switch 42 (FIG. 1), CPU 10
2 enters a start mode 202 and executes an initialization program (INITIALIZ) 204. Next, execute the monitoring program (MONIT) 206 and perform the back ground job (BACK
GROUND JOB) 208 is executed. Examples of this bug ground job include the task of calculating the EGR amount (hereinafter referred to as EGR・TASK) and the task of calculating the opening degree of the bypass valve 14 (hereinafter referred to as ISC・TASK).
(denoted as TASK). During execution of this task, when an interrupt factor (hereinafter referred to as IRQ) occurs, the process jumps to point 222 to analyze the interrupt factor, and the interrupt factor analysis program 2
24 (hereinafter referred to as IRQ ANAL). This interrupt factor analysis (IRQ ANAL) program further includes ADC1 end interrupt processing (hereinafter referred to as ADCIEND).
IRQ) program 226, ADC2 end interrupt processing (hereinafter referred to as ADC2END IRQ) program 228, and certain period elapsed interrupt processing (hereinafter INTV)
It consists of an engine synchronous interrupt processing (hereinafter referred to as IRQ) program and an engine synchronous interrupt processing (hereinafter referred to as INTL IRQ) program, and issues a startup request (hereinafter referred to as QUEUE) to each task that needs to be started (described later). This interrupt analysis (IRQ ANAL) program 22
Each program in 4 ADC1 END IRQ226 and
ADC2 END IRQ228 and INTV IRQ230
Each task for which a start request (QUEUE) is issued by each program of INTL IRQ 232 is level zero task group 252, level 1 task group 254, level 2 task group 256, and level 3 task group 25.
8, or the tasks constituting each task group. Also INTV IRQ program 232
The task that generates a start request (QUEUE) when engine stoppage is further detected is an engine stoppage processing task 262 (hereinafter referred to as ENST TASK). When this ENST TASK 262 is executed, the control system enters the start mode again and returns to the starting point 202. The task scheduler 242 schedules tasks so that they are executed starting from the task group with the highest level (here, level zero is the highest) among the task group for which a start request (QUEUE) has occurred or the task group whose execution has been suspended. Determine the order of execution. When the execution of the task group is completed, the completion report program 2
60 (hereinafter referred to as EXIT), the completion is reported. Based on this completion report, the task group with the highest level among the task groups waiting for execution is executed next. When there are no more suspended tasks or tasks for which a QUEUE has been issued, the task scheduler 242 starts executing the background job 208 again. Furthermore, if an interrupt (IRQ) occurs while any of the level 0 task group to level 3 task group is being executed, the process returns to the starting point 222 of the interrupt analysis program. Table 1 shows the activation of each task described above and its functions.

【table】

[Table] In Table 1, interrupt analysis (IRQ ANAL) is a program for managing the control system.
Programs and task schedulers (TASK)
SCHDULER) program and exit report (EXIT)
There is a program. These programs (below
OS) is held at addresses A000 to A300 of the ROM 104 as shown in FIG. The address is expressed in hexadecimal notation. Additionally, AD1 as a level zero program
There are programs for capturing the output of AD2 (AD1IN), capturing the output of AD2 (AD2IN), and capturing the engine rotational speed output (RPMIN), which are usually started at 10 [mSEC] of a certain time elapse interrupt (INTV IRQ). Level 1 programs include fuel control (INJC), ignition timing control (IGNCAL), and conduction angle control (DWLCAL) programs, which are activated every 20 [mSEC] of a fixed time interrupt (INTV IRQ). There is a 02 feedback control (LAMBDA) program as a level 2 program, which is activated every 40 [mSEC] of a fixed time elapsed interrupt (INTV IRQ). There is a correction calculation (HOSEI) program as a level 3 program, which is activated every 100 [mSEC] of a certain time elapsed interrupt (INTV IRQ). There are also exhaust recirculation control (EGRCAL) and bypass air control (ISCCAL) programs as background jobs. The above level zero program is stored as PROG1 at addresses A600 to AAFF of the ROM 104 in FIG. 4, respectively. The level 1 program is stored as PROG2 at addresses AB00 to ABFF in the ROM 104. Level 2 program is PROG3
are stored in the ROM 104 from address AE00 to AEFF. Level 3 program is PROG4
They are stored in the ROM 104 from addresses AF00 to AFFF. Also, background job programs are held in B000 to B1FF. A list of start addresses for each program from PROG1 to PROG4 (hereinafter referred to as SETMR) is held from B200 to B2FF, and a value representing the start cycle of each program from PROG1 to PROG4 (hereinafter referred to as TTM) is stored in B200 to B2FF. Stored at addresses B300 to B3FF. These details are shown in FIG. Other data is stored at addresses B400 to B4FF of the ROM in FIG. 4 as necessary. This is followed by a data ignition timing map (ADV.
MAP), air-fuel ratio control map (AF.MAP), and exhaust gas control map (EGR.MAP). Explain the initialization program. Initialization INITIALIZ2 in Figure 3
The details of the 04 program will be explained using FIG. In step 282, a save area is set when an interrupt (IRQ) occurs. Next, in step 284, the RAM is
Clear all 106. In step 286, initial values are set in the registers of the input/output circuit 108. For example, for this initial value setting, angle sensor 1
There are 46 initial measurement time values, DDR settings for different uses of DIO terminal input and output, and timer settings for generating interrupts after a certain period of time (INTV IRQ). In step 288, ADC1 is activated, and
Release the prohibition for ADC1 end interrupt (ADC1 ENDIRQ). In this case, specify the multiplexer (MPX) input to ADC1,
Send a pulse to start ADC1. This allows the battery voltage detection sensor VBS12, which is one of the inputs of the multiplexer MPX of ADC1 in Figure 2, to
The output of 2 is selected and input to ADC1.
Return to step 290 and enter ADC1 END IRQ here.
have. ADC1 conversion operation is completed and REG134
When the digital value is set, the completion of the operation of ADC 164 is reported to status register STAUS 198, and ADC1 END IRQ is input to CPU 102. As a result, the program AD1 IN is executed and the output of the battery voltage sensor 132 is taken in. In step 292, it is confirmed whether all outputs from the sensors 122 to 82 have been taken in. In this case, the process returns to step 288 since the capture of the input from sensor 122 has only been completed. This step 288
Then, the multiplexer (MPX) 162 selects the next input, the output of the sensor 74. When the analog-to-digital conversion of the output of the water temperature sensor 74 is completed, the program AD1 is converted again in step 290.
IN (intake) is executed and register REG134
The digital value of the output of the water temperature sensor TWS 74 held in the ROM 104 is taken in and held in the data (DATA) area of the ROM 104. At step 292, the process returns to step 288. In this way, by going through the loop from step 288 to step 292, the digital values of the outputs from the sensors 122 to 82 are taken in one after another, and when the reading of the output value of the exhaust gas sensor λS 82 is completed, the process proceeds to step 294. In step 294, the ignition timing at startup is calculated and set. This ignition timing θADV (ST) is calculated as a function of the engine cooling water temperature TW. This function is shown in FIG. According to the characteristics shown in Figure 7, θADV
(ST) and the calculated result is shown in Figure 2.
Set in register ADV of IGNC156. At step 296, the air bypass
The initial value of the valve 14 is calculated. This calculation is performed based on the characteristics shown in FIG. 9, and the calculation output is set in the register ISCD of the control circuit ISCC 164. A fixed value is also set for ISCP. This fixed value is determined by the characteristics of the control valve. The characteristics shown in FIG. 8 are characteristic diagrams of INJD set values. In step 298, an initial value of on-duty, which is the fuel injection time, is calculated. This calculated value is calculated according to FIG.
2 register INJD. register
By setting INJD, execution of the initialization (INITIALIZ) program 204 shown in FIG. 3 ends. Next, the monitoring program 206 will be explained. FIG. 6 shows the MONIT program 206. The MONIT program 206 starts at step 302,
In step 302, the starter switch 6 of FIG.
This is done by monitoring the DIO5 input of DIO to see if DIO6 is in the ON state. If the starter switch 66 is in the ON state, the fifth bit DIO5 of DIO is "H". Conversely, when it is OFF, it is "L". Assuming that the engine has not yet started, the starter switch is OFF, and the process proceeds from step 302 to step 312, where it is determined whether or not the engine has been started. This determination is made, for example, by determining whether a starter flag is set. This starter flag is set in step 308. This starter flag is
Set to a specified location in RAM. The starter flag is not set before starting, so step 3
12 is NO, and the process returns to step 302 again.
The route goes from step 302 NO to step 312 NO and back to step 302 until the starter switch 152 is turned on. While going around this route, monitor the starter switch. When the starter switch is turned on, step 30
In step 2, the determination is YES, and the process proceeds to step 304.
At this point, determine whether the starter switch was already turned on. When proceeding to step 304 for the first time, it is immediately after detecting that the starter switch is ON, and the starter flag is not set, so the determination at step 304 is NO. Starter
If the flag is not set, the judgment is NO and the process proceeds to step 306, where preparations for starting are made.
For example, in this embodiment, the fuel pump 190
To start up, the zeroth bit of DOUT register 194 of DIO is set to "H". This turns on the fuel pump. Next, in step 306, the first bit of the DOUT register 194 is set to "H". As a result, the IGNC circuit 156
AND gate 160 provided at the output of is activated. Actually DOUT register 194
The setting of the zeroth bit and the first bit of is performed simultaneously. In step 308, a certain time elapsed interrupt (INTV
IRQ) is lifted. To cancel the inhibition of this certain time elapsed interrupt (INTV IRQ), for example, set the 4th bit of the MASK register 196 to “H” in Fig. 2.
This is done by making Further step 308
Set the starter flag. This starter flag already indicates that the starter switch is ON, and steps 304 and 312
This flag is used for judgment. In step 310, the control circuit INJC, the control circuit IGNC, and the control circuit which are the output system of the input/output circuit 108 are connected.
In order to put the AND gates at the output terminals of ISCC and the control circuit EGRC into operation, a mode register 172, which will be described later, is set to "H". This sends a pulse output to each control device. Step 31
The process returns to step 302 from 0, and in step 302 it is determined whether the starter switch 152 is ON. The starter switch is ON during starting, and the process advances to step 304 from YES. In this step 304, the starter flag is checked and
If the flag is set, it is assumed that the start has already started, and the process returns to step 302. While the starter motor is being driven in this manner, a loop formed by YES in steps 302 and YES in 304 is being executed. When the engine is started, starter switch 1
52 is turned off, the determination at step 302 is NO, and the process proceeds to step 312. The starter flag is checked in step 312, and since the starter flag is set, the process advances to step 314. In this step 314, an engine stall flag is set to detect engine stalling and release the prohibition of processing, and after this step 314, engine stalling can be detected at the engine stall detection step of the INTVIRQ and INTLIRQ processing programs. Next, proceed to the background job program 208. This program is detailed in FIG. In the figure, at step 410 it is determined whether throttle switch 76 is ON. if
If ON, exhaust gas recirculation control will not be performed. Therefore, proceed to step 412, where the register
Set EGRD to zero. Due to this
The opening rate of the EGR valve 62 becomes zero. On the other hand, in step 414, a predetermined value is set in ISCD. Therefore, the air bypass valve 14 of FIG. 1 is controlled according to the value set in the register ISCD. Air bypass valve 14, which controls the air flow rate in the bypass passage, is controlled according to specific operating conditions. That is, the air flow rate in the bypass passage is increased when driving in the winter when the temperature is low, when starting the engine when it is cold, when driving while using a car air condenser that places a load on the engine, etc. In step 414, the duty of the air bypass valve 14 is set in the register ISCD according to the cooling water temperature. The engine rotation speed during idling is controlled according to this value.
Upon completion of step 414, the process returns to step 410, and this flow is repeated. On the other hand, when the throttle switch 76 is not on, the air solenoid valve 22 is not closed, and exhaust gas recirculation control is performed instead. For this purpose, in step 418, the register ISCD is set to zero. In step 422, it is determined whether the cooling water temperature is higher than a certain value, for example, TA°C, and if it is higher, EGR is not applied. Therefore, in step 426, a value of zero is set for performing EGRCUT. Also, if the cooling water temperature is lower than a certain value (TA°C) in step 422, the process proceeds to step 424.
Proceed to. In step 424, it is determined whether the cooling water temperature is lower than TB°C. If it is low, then
Since EGR is not applied, EGRCUT is performed in step 426.
Set the value to zero. These values are set in the EGRD register at step 430. On the other hand, if the cooling water temperature TW is higher than TB degree and lower than TA degree, EGR is performed. The EGR amount at this time is determined by the output VC of the pressure sensor 78 and the engine rotation speed N. A map of the EGR amount based on the outputs VC and N is provided at addresses B700 to B7FF of the ROM in FIG. 4, and the EGR amount is determined by searching from this map. A search is performed in step 428, and this value is set in register EGRD in step 430. The EGR device 62 shown in FIG. 1 is driven according to the set value of the register EGRD. In the flowchart shown in FIG. 10, upon completion of step 430 or step 414,
The process returns to step 410 again. By doing so, the computer can always execute the flowchart from steps 410 to 414 or from steps 418 to 430 for controlling the air bypass valve 14. Therefore, assuming that an interrupt (IRQ) etc. does not occur, a program started at point 202 will back up through an initialization (INITIALIZ) program 204 and a monitoring (MONIT) program 206.
The ISC program or EGRCAL program, which is the ground job 208, will continue to be executed at all times. Monitoring (MONIT) program 206 and back
The ground job 208 is designed to be able to interrupt its processing by generating an interrupt (IRQ).
When the processing by interrupt (IRQ) is completed, execution of the above program is resumed. Next, the processing based on the occurrence of an interrupt (IRQ) in FIG. 3 will be explained. The interrupt (IRQ) factor analysis program 224 includes processing of ADC1 END IRQ 226, processing of ADC2 END IRQ 228, and INTV.
It consists of IRQ230 processing and INTL IRQ232 processing. Here, each program 226,
In order to execute each of steps 228, 230, and 232, first, it is determined what the request for the service based on the interrupt (IRQ) is. For this purpose, the contents of the status (STA TUS) register 198 in FIG. 2 are examined. By looking at the contents of this status (STA TUS) register, the cause of the interrupt (IRQ) can be determined. The programs 226, 228, 230, 232 are executed according to the cause of the occurrence, and the tasks (TASK) 252, 2 are executed.
A start request (QUEUE) is issued to a task (TASK) that needs to be executed among 54, 256, 258, and 262. However, if the occurrence of interrupts (IRQs) increases, the execution time of the management program (hereinafter referred to as OS) increases, and there is a drawback that it becomes difficult to take the calculation time for actual engine control. Therefore, in this example,
ADC1END IRQ 228 is generated only during execution of initialization (INITIALIZ) or monitoring (MONIT) programs 204 and 206, and is not generated at other times. That is, at step 314 shown in FIG. 6 of the MONIT program 206, the MASK register 196 of FIG.
ADC1END Sets the IRQ prohibition command to “L”. Also, set the mask (MASK) register so that ADC2END IRQ 226 is not generated from the beginning, that is, all interrupts are prohibited at the starting point 202, and the IRQ generation is prohibited by the general reset signal of the input/output circuit. .
After that, generation of ADC2END IRQ is prohibited by not issuing an instruction to cancel interrupt (IRQ) prohibition. Specific examples of the program 224 are shown in Figures 11 to 14.
As shown in the figure. If it is determined in step 450 from the interrupt (IRQ) entrance 222 that it is not the ADC1END IRQ, the process goes to step 452. On the other hand, it is determined whether the cause of the interrupt (IRQ) is the ADC1END IRQ, and if so, the program jumps from step 450 to step 290 of the initialization (INITIALIZ) program. In this embodiment, the ADC1 END IRQ is generated only during execution of the initialization (INITIALIZ) program 204 shown in FIG. 5. ADC1END IRQ is prohibited in any other state. If the determination at step 450 is "NO", the process advances to step 452. In step 452, the cause of the interrupt (IRQ) is a certain time elapsed interrupt (INTV IRQ) that occurs at a certain period.
determine whether If “YES”, proceed to step 454. Step 454 to Step 45
8 is combined with step 482 in FIG. 12 to detect the stopped state of the engine. Already step 45
At step 4, it is determined whether or not the engine stall state should be detected based on whether the engine stall detection flag is set. This engine stall detection flag is set only when it is necessary to detect engine stall. If this flag is reset in step 454, the engine stop detection is not performed and the process proceeds to step 460. On the other hand, if the flag is set, the process advances to step 456 to detect engine stoppage. In this step, the count value of the engine stall counter is updated to measure the elapsed time from the REF signal generated at the reference rotation angle of the engine output shaft. This engine stall counter is REF, which represents the reference rotation angle.
Since it is cleared after each signal, the stalled counter value represents the elapsed time since the previous REF signal occurrence.
If the engine stall count value has reached the specified value in step 458, it is determined that the engine has stopped, and the process advances to step 474 to execute the engine stall task (ENSTTASK) (FIG. 14). The contents of the engine stall task (ENSTTASK) are as follows.
In order to stop the fuel pump 24, the procedure shown in FIG.
Changing DIOO from “H” to “L”, 2nd
AND gates 154, 158, 166, 17 in the figure
0 to the halt state, setting the mode (MODE) register 172 to "L" and jumping to the starting point 202 of the program system. If it is determined in step 458 that the engine has not stopped, the process advances to step 460. Steps 460 to 470 are task level
It has a function to judge whether programs from zero to task level 3 have reached the start timing. First, check task level zero. To this end, in step 460, the contents of a predetermined address in the RAM representing number n of the task control word (TCW) are set to zero. task level
Zero task control word, bits b0-b5 of TCW0 in RAM 106 in FIG.
Increment counter 0 by +1. In this way, although the addition method is adopted in this embodiment, it is also possible to adopt the subtraction method. At step 462, the value of the counter of TCW0 is compared with the value of the task activation timer TTM0 of FIG. Here, TTM0 contains “1”.
Here, the certain time elapsed interrupt (INTV IRQ) is 10
Since it is assumed that it occurs every [mSEC],
“1” in TTM0 means that the task level zero program (252 in Figure 3)10
This indicates that it is activated every [mSEC].
The TCW0 counter (CNTR0) in Figure 15 and
TTM0 is compared in step 464, and if they match, the process goes to "YES". In this case, since they match, the process advances to step 466, and a flag "1" is set in bit b6 of the task control word TCW0.
In this embodiment, b6 of each TCW becomes a flag for the activation request (QUEUE) of that task. Step 46
In step 6, flag “1” was set in b6 of TCW0, so the counters set in b0 to b5 of this TCW0
Clear CNTR0. TCW at step 468
Increment n. That is, step 4
In step 68, the process moves to start timing search from task level zero to task level 1. Step 470
Determine whether task level 3 is finished. In other words, it is determined whether n=4. In this case, since n=1, the process returns to step 462. At step 462, the task control word for the task level 1 program, stored in RAM 106 in FIG.
Increment the contents of counter CNTR1 of TCW1 by "+1". In step 464, the steps shown in FIG.
Compare with TTM1 of ROM104. In this embodiment, the content of TTM1 is "2". In other words, the activation timing of task level 1 is 20 [mSEC]. Assuming that the content of the counter CNTR1 is "1", the determination at step 464 is "NO", that is, it is determined that it is not time to start the task level 1 program 254, and the process advances to step 468. Here, the task level to be searched again is updated, and the next task level is task level 2. Similarly, when task level 3 is completed, step 46
8, n=4, and in step 470, n=4.
The condition nMAX(4) is satisfied. And the task
Proceed to Stigiura 242. In step 452, a certain time elapsed interrupt (INTV
IRQ), the process advances to step 472. Here, it is determined whether a reference angle interrupt (INTL IRQ) occurs at each reference rotation angle of the engine's output shaft. In this case, the answer should always be YES, but if a malfunction occurs due to noise or the like, the answer will be NO at step 472, and the state will return to the state before the interrupt. On the other hand, in the case of reference angle interrupt (INTL IRQ), step 48 in Figure 12
Proceed to 2. Here, step 456, 4 in FIG.
58 to detect the stopped state of the engine. In other words, the engine stall counter is set to step 482.
Clear with . In step 484, it is determined whether the fuel pump is operating or not. If it is stopped, it means that the engine output shaft has rotated to the reference rotation angle, so in step 490, DIOO of DIO in FIG. 2 is set to "H". This will put the fuel pump into operation. At step 502, processing is performed to prevent sudden changes in engine torque due to sudden changes in ignition timing. Hereinafter referred to as DYNAMITSU LIMITATION (DYNAL). The details will be described later using FIG. 13. In step 504, the engine speed is read and it is determined whether the engine speed exceeds the maximum speed nMAX. If nMAX is exceeded, step 510 is performed to reduce the engine output torque.
Proceed to. Steps 520 to 524 are steps for thinning out ignition operations. In other words, AND in Figure 2
The gate 160 is intermittently activated. In step 520, it is determined whether the output of DIO1 is "H", and if it is "H", DIO1 is set to "L" in step 522 to stop ignition. If not, DIO1 is set to "H" in step 524. This causes intermittent ignition. In steps 506 to 514, it is determined whether the pressure P in the intake manifold exceeds the maximum pressure PMAX. It is dangerous if the pressure exceeds PMAX. This PMAX has a characteristic as shown in FIG. 18 with respect to the engine rotation speed. The characteristics shown in FIG. 18 are divided into bands of engine rotational speeds, for example NA to NM, and the lowest PMAX value in each band is selected as the representative value of that band, as shown in FIG. 19. It is stored in ROM addresses B800 to B80D. First, in step 506, the number Z is set to zero.
This Z represents the order of the bands NA to NM. At step 508, the band boundary value is read from the first address B80E+Z. In other words, initially the value of the boundary NO between bands NA and NB is address B80E.
read out. Therefore, in step 508, the engine rotational speed n is compared with the rotational speed value at the boundary between bands NA and NB stored at address B804. If the engine speed n is greater than this boundary value, the process proceeds to step 510, where Z is incremented. As a result, the value to be compared with the actual rotational speed n shifts to the value of N1 read from address B80F. This value of N1 is the boundary value between band NB and band NC. In this way, the actual engine speed n is compared with successively read boundary values, and the number Z is incremented each time. When the actual engine speed value n becomes smaller than the boundary value, the process proceeds from step 508 to step 5.
Proceed to step 12. In step 512, the value of Z which means this band order is used, the number from address B800 is determined by the value of Z, and the maximum pressure is set to B800.
It is read from the +Z address. This maximum pressure
PMAX and measured pressure P are compared, and this maximum pressure
If PMAX is exceeded, proceed to step 520 to reduce engine torque. On the other hand, when the manifold pressure is lower than the maximum pressure, the DIO1 output of DIO is set to "H", and the AND gate 160 (Figure 2)
is in the operating state. Then proceed to the task scheduler program. Explain the DYNAMITSU LIMITATION PROGRAM (DYNAL). FIG. 13 is a detailed flowchart of the dynamic limitation program (DYNAL) shown in FIG. 12. Table 1 in the Level 1 program described below
The target value θTARGET of ignition timing is calculated by the IGNCAL program shown in . The difference between this target value and the previous ignition timing θ(t-1) is calculated in step 532. In step 534, it is determined whether the magnitude of this difference Δθ is larger than the constant width ΔQMAX.
If ΔθKAX is not larger than ΔθKAX, the target value θTARGET is set as the current ignition timing in step 536 because the difference between the target value and the previous ignition timing is small. On the other hand, if it is determined in step 534 that the difference between the target value and the previous ignition timing is large, then step 53
8, 540, and 542, processing is performed to approach the target value only by a certain angle. That is, it is determined whether the target value θTAGET is larger or smaller than the previous ignition timing. This target value and the previous ignition position θ(t-1)
In this embodiment, is expressed by the number of POS pulses which are unit pulses from the sensor 80 between the reference rotation angle before the ignition position and the ignition angle. Therefore,
Satisfying the condition θTAGET>θ(t-1) means that the ignition timing needs to be moved to the retarded side; otherwise, it means that the ignition timing needs to be moved to the advanced side. In step 538, if the target value θTAGET is larger than the previous ignition position θ(t-1), in order to bring the current ignition position closer to the target value, a value θ(t-1)+Δθ1, which is obtained by adding a constant value Δθ1, is set this time. ignition position θ
(t). On the other hand, if not, θ(t-1)
The current ignition position θ(t) is obtained by subtracting the constant value Δθ2 from θ(t-1)−Δθ2. At step 544,
θ(t) obtained in any of steps 536, 540, and 542 is applied to the input/output circuit 108 of FIG.
Set to register ADV of IGNC156.
The process then continues to step 504 in FIG. Figure 14 is the ENST TASK.
This is a detailed flowchart of step 474 of FIG. As explained in step 474, the mode register (MODE) 172 is set to "L" in order to stop the fuel pump and stop all outputs from the input/output circuit 108 in FIG. Thereafter, it jumps to the start point 202 address. FIG. 16 is a detailed flowchart of the task scheduler 242, which determines at step 560 whether task level n needs to be executed. Initially, n is cleared, so n=0. task·
Determine the need for level zero program execution. That is, the existence of a start request (QUEUE) is checked in order of priority.
This can be determined by searching b6 and b7 of task control word TCW in RAM 106 in FIG. b6 is a startup request flag, and when it is set to "1", it can be seen that a startup request is "present". Also, b7 is a flag indicating that the process is being executed, and when "1" is set here, it indicates that the process is being executed and is currently suspended. accordingly
If at least either b6 or b4 is "1", execution is required and the process advances to step 568. At step 568, the flag b7 is determined, and if b7 is "1", execution is being suspended, and execution of the suspended task is resumed from point 570. b6 and
Even if both flags b7 are set, the determination at step 568 is still "YES" and the program is restarted from the interrupted program. Only b6 is “1”
, then the boot request flag for that level i.e. b6
is cleared in step 572, and then cleared in step 574.
Set the b7 flag (hereinafter referred to as the RUN flag) with . Steps 572 and 574
Indicates that the level has progressed from the startup request state to the execution state. At step 578, the task level
Find the start address of a program. This is obtained from the start address table TSA provided in the ROM 104 shown in FIG. 15 in correspondence with the TCW of each task level.
Task start address table (TASK START ADDRESS) in ROM 104 shown in Figure 5
(n+TASK・START・
The task is executed by determining a read address from the equation (starting address of ADDRESS) and jumping to this start address using the stored contents at this address as a start address. Returning to FIG. 16, if the determination in step 560 is "NO", this indicates that the search task level program has not been requested to start, nor has its execution been interrupted. In this case, the search will proceed to the next task level. In other words, the task level n becomes n+1, and the task level moves by one level. Here, it is checked whether n is MAX, that is, 4 in this case, and if it is not 4, the process returns to step 560. Repeat this and when n=4, the point 566
Return to the point where Back Ground Job left off. In other words, at point 566, task level zero ~
It turns out that all programs up to 3 do not need to be executed, and the process returns to the point where the background job was interrupted before the IRQ occurred. Figure 15 shows the task control system mentioned above.
This figure shows the relationship between the word TCW, the TTM representing the task start cycle in the ROM, and the task start address table. ROM corresponding to 0 to 3 of task control word TCW
There is a task activation period TTM in the TCW counter, and the TCW counter is
CNTR0~3 are updated individually and each task's
When the TTM matches, a flag is set in b6 of the TCW. This flag then searches the task start address TSA in the ROM for the start address of the task, and jumps to that start address. Selected programs 1 to 4 are executed. During this execution, a flag is set in b7 of the TCW corresponding to the program in the RAM 106. As long as this flag is set, it can be determined that the program is being executed.
In this way, task scheduler 2 in Figure 3
42, programs at levels 0 to 3 are executed. For example, if an interrupt (IRQ) occurs while any of the programs 252 to 258 at levels 0 to 3 is being executed, the task is interrupted again and the interrupt (IRQ) is processed. The task whose execution has just started due to the occurrence of an interrupt (IRQ) will eventually end its processing. In order to make an exit report, the exit report (EXIT) program 26
Jump to 0. The details of this exit report (EXIT) program are shown in FIG. This program consists of steps 592 and 594 for finding finished tasks. In steps 592 and 594, the task
Search from level zero to find the finished task level. This advances to step 596, where the flag b7 (RUN flag) of the task control word (TCW) of the completed task is reset. This means that the program has completely finished executing. Then, the process returns to the task scheduler again, and the next execution program is determined. FIG. 20 is a level 0 program. As shown in this program and Table 1, a startup request is issued every 10 milliseconds. ADC1 at step 650
At step 654, the next data to be acquired is selected, and at step 656, the ADC 1 is activated to acquire the next data. Also 652
The step is to use ADCEND IRQ before startup, and if the pre-start flag is set,
Since it has not yet started, restart the interrupt interruption (RTI), that is, return to the interrupted program. This program is the initialization (INITIALIZ) program 204 shown in FIG. In step 658, intake manifold pressure P, which is data of AD2, is fetched, and in step 670, ADC2 is activated to fetch the next data. Step 67
2 takes in the engine speed. After this, in step 674, it is determined whether the start-up is complete. If starting is completed, the process jumps to step 682. On the other hand, if this is not the case, it is determined in step 676 whether it is before starting or during starting. If the measured speed N of the engine has not reached the starting rotational speed, the engine has not yet been started, and the process jumps to step 682. If the engine is starting, the process moves to step 678, and the mode (MODE) register 172 is set to "H" in order to release the inhibition of output from the input/output circuit 108 shown in FIG. Then, a flag indicating that the engine is starting is set. Note that this level (LEVEL) zero task is requested to start every 10 mSEC, so it is executed approximately every 10 mSEC. Therefore, during startup, steps 678 and 68 are executed every 10 mSEC.
0 is executed. Once set, no actual harm will occur even if flags or data with the same purpose are set. Standard rotation angle interrupt (INTL IRQ) at step 680
In order to make it possible to accept the request, an "H" flag is set in the MASK register 196 shown in FIG. 2, and an engine stall detection flag is also set in order to detect engine stoppage. This detection flag is used in step 454 of FIG. In steps 682 and 684, if the engine speed is greater than the idle speed value NLL, the NLL flag is set. At step 686, it is determined whether the start-up is complete. If the measured value N is greater than the rotational speed at which it can be determined that the start has been completed, it is determined that the start has been completed, and a start complete flag is set. If not, reset the NLL flag. And this level (LEVEL)
The zero task has finished, and in order to report its completion,
Jump to the exit report (EXIT) program 260 and clear the b7 bit flag of RAM 106TCW0 in FIG. FIG. 21 shows a level 1 program, and in step 702 it is determined whether the program is being started. When starting, fuel is supplied during starting and ignition timing is determined, so step 70 is performed for these calculations.
Proceed to step 4. In step 704, starting fuel is determined based on the engine cooling water temperature value TW. Also, in step 706, the engine rotation speed N and water temperature TW are determined.
The ignition position θ is determined based on the following. On the other hand, if the engine is not starting, the fuel supply amount is determined from the intake manifold pressure P and engine speed N in step 708, and the control circuit INJC15 in FIG.
Set to the INJD register of 2. Next, steps 710 to 724 are a flowchart for calculating the ignition position. The ignition advance value W controlled here has a characteristic as shown in FIG. 22 with respect to the engine rotational speed N.
In other words, when the idle rotation speed becomes lower than the NLL value, the angle is advanced toward the advance value W2. This increases torque output and lowers the engine speed to the target value.
Get closer to NLL. It should be noted that at the target rotational speed NLL, the advance angle amount is small and the value is W1, and since the ignition advance angle is small with respect to the engine rotational speed, the torque output is small. Therefore, the engine rotational speed should be balanced around the target rotational speed NLL value. Note that the advance angle value when the throttle switch is open and access is depressed is not shown in FIG. in this case,
Specifically, it is determined by a function of manifold pressure P and engine rotation speed N. This relationship shows the address of ROM104 as an ADV map as shown in Figure 4.
Stored in B500~B5FF. In step 710, it is determined whether the throttle switch is closed, and if it is closed, in step 712 it is determined whether the address rotation speed is greater than NLL. If it is larger here, step 71
6, an angle θ corresponding to the ignition advance angle W shown in FIG. 22 is determined as a function of the engine rotational speed N.
As shown in FIG. 22, this value W is constant near NLL even if the rotational speed N increases, so as the rotational speed N increases, it becomes retarded compared to the maximum torque output characteristic. Therefore, the output torque decreases. However, when the rotational speed is significantly larger than the target rotational speed NLL, the angle is advanced in accordance with the rotational speed N as shown in FIG. This area is used when engine braking is applied at high speeds, and is determined by taking into consideration factors such as smooth driving and exhaust gas conditions. In any case, the ignition position is determined so that if the rotational speed N is greater than NLL, the deceleration characteristic is applied, and if not, the ignition position is determined so that the acceleration characteristic is applied. If the throttle switch is open, θ is determined from the pressure P and rotational speed in step 718. When this pressure P is larger than the specified value (pressure indicating the start of turbocharger operation), a correction coefficient θC is added to θ obtained in step 718 in step 722, and the value is set as θ. This correction coefficient θC is obtained in a level 3 task. Details will be described later. Step 724 is for correcting the time from receiving the ignition pulse until the ignition coil current control section including the power transistor operates, and the correction amount f(N) has a characteristic as shown in FIG. In other words, the delay in the control section is considered to be approximately a constant time, and the engine rotation angle corresponding to this time is determined as f(N),
At step 724, f(N) and θ are added,
Let this value be θTAGET. This θTAGET is the first
It is used in steps 532 to 544 of the dynamic limitation explained in FIG. Steps 726 to 734 are safety measures, and in step 726 the rotation speed N is the maximum rotation speed.
If NMAX is exceeded, the process jumps from step 726 to step 734 and turns off the fuel pump. If the maximum rotational speed NMAX has not been exceeded, the maximum value of the pressure is determined in step 728. This is the 12th
This operation is the same as the flow for determining PMAX through steps 506 to 512 in the figure. Pressure P is PMAX
If so, jump to step 734 to turn off the fuel pump. If not, turn on the fuel pump. Note that no problem will occur even if data is set in the input/output circuit to turn it on further when it is already in the on state. Thereafter, in step 736, the flow start point of the primary current in the ignition coil is calculated, and the level 1 program is terminated by jumping to the exit report (EXIT) program. Figure 24 is a level 3 program;
The correction amount θC used in the figure is determined. If the pressure becomes greater than the pressure at which the turbocharger started operating, the ignition position is shifted as the turbocharger operates. This shift value θC is obtained from the characteristics shown in FIG. In other words, using the intake air temperature TA as a parameter, when the intake air temperature is low, the ignition position is on the advance side, and as the intake air temperature rises, it moves to the lag side.
Therefore, the correction value θC becomes a larger positive value as the intake air temperature TA becomes higher. FIG. 26 is a detailed diagram of the control circuits EGRC168 and ISCC164 in FIG. 2. In Figure 2, ISCD and
Each register of EGRD represents the pulse width.
Corresponds to register 802. Also ISCP and EGRP
The register corresponding to 806 is 806. Assume that bit b0 of the mode (MODE) register 172 is set to "H". Therefore, AND gates 166 (Fig. 2) and 816 are both in operation. A timer 804 consisting of a counter circuit counts the clocks from an AND gate 816. This count value B is compared with the value of the register 806 by the comparator 810, and when the value of the count value B exceeds the value C of the register 806, the timer 804
is cleared. Therefore, the timer 804 repeats counting at a period determined by the value C of the register 806. Further, the count value of the timer 804 is compared with the value of the register 802 by a comparator 808. At this time, the value A of the register 802 is the count value B of the timer 804.
The flip-flop 812 is set under a larger condition, and reset under the condition that the value B is greater than or equal to the value A. Therefore, the set time of flip-flop 812 is determined by the value A of register 802. By increasing this value A, the flip-flop 81
The setting time for 2 is longer. Furthermore, as mentioned above, the count of timer 804 is repeated at a frequency corresponding to the set value of register 806, so that the set output of flip-flop 812 is repeatedly output according to the repetition period according to the set value of register 806. MODE register 1
Since the b0 bit of 72 (Fig2) goes to “H” level,
It is output via AND gate 166. When b0 of MODE register 172 is set to “L”
AND gates 166 and 816 are turned off, the output of flip-flop 812 is stopped, and at the same time the input to timer 804 is also stopped. Therefore, to the MODE register 172 shown in FIG.
By setting control data from the CPU,
The start or stop of the circuit operation shown in FIG. 26 can be controlled. FIG. 26 shows an example in which AND gates 166 and 816 are controlled by b0 of the MODE register, and b0 is the bit that controls ISCC 164 in FIG. The EGRC 168 in FIG. 2 has the same configuration as in FIG. 26, but the start/stop of the ISCC 164 operation is controlled by the b0 bit of the MODE register, and the EGRC 168 is controlled by the b2 bit. FIG. 27 is a detailed view of the IGNC 156 in FIG. The CPU sets the data that controls the starting point of primary current to the ignition coil to the DWL register.
Data representing ignition timing is set in the ADV register. Now set the DWL register value to A,
Let C be the set value of the ADV register. Now, the b1 bit of MODE Resta 172 is “H”
, AND gates 158 and 860 are in a communicating state, and the POS pulse is input to counter 850 through AND gate 860. This count value of 850 therefore increases with the engine crank angle and indicates the reference angle.
Cleared by REF pulse. Let this count value be B. When the count value is small, the output of comparator 852 (A>B) is applied to flip-flop 856 via an OR gate, and flip-flop 856 is reset. Therefore, no pulse output is output from AND gate 158. When the count value of the counter 850 increases, the count value of the counter 850 becomes larger than the value A of the DWL register, and the flip-flop 856 is set via the AND gate 864. This set output is
The primary coil current is applied to the ignition system through AND gate 158 and further through AND gate 160 of FIG. 2 to flow the ignition coil. When the count value becomes higher still, the flip-flop 856 is turned OFF again due to the C≦B output of the comparator 854.
As a result, the pulse output from the AND gate 858 is stopped, and a spark for ignition is generated. Details of DIO in FIG. 2 are shown in FIG. 28. In this diagram, DDR192 is from DIO input/output port DIO0.
This determines whether DIO7 is in the input state or output state. The signal from the bit set to “H” in DDR corresponds to 872~
It is added to the tristate of 886 and the tristate becomes conductive. As a result, the DOUT bit corresponding to the "H" bit of DDR is outputted via the corresponding tri-state. On the other hand, the signals on lines DIO0 to DIO7 can be freely read by the CPU via buffer amplifiers 892 to 904. Since the signal on the line corresponding to the non-conducting tristate among the tristates 872 to 886 depends on the external state, the external state can be read for this line. Figure 29 is a detailed diagram of INJC152 in Figure 2, and the REF pulse from the crank angle sensor is set at a certain angle (for example, 80 degrees or 90 degrees) before the top dead center of the crank angle.
Occurs at (degrees). Crank angle top dead center (TDC)
The relationship between REF and REF is shown in A and B of Fig. 30. now
Assuming that the b4 bit of the MODE register 172 is "H", the gates 910, 912,
154 (Fig2) is ON. Therefore, the count value of the counter 904 is as shown in FIG. 30C.
Cleared on every REF pulse. register 902
The value A is a register that receives and holds the value that determines the injection start point from the CPU. Value A of register 902 and count value B are set to comparator 906,
Set flip-flop 908. When flip-flop 908 is set
A pulse is sent from the AND gate 154 and sent to the injection valve 28. Furthermore, the gate 912 is opened and a timer 916 consisting of a counter counts the clock pulses. The INJD register 914 is the INJD register of FIG. 2, and the valve is opened for a time corresponding to the set value C of this register. That is, while the count value D of the timer 916 is smaller than C, the flip-flop 920 is set;
Under the condition of ≦D, the flip-flop 920 is reset and the injection pulse from the AND gate 154 is stopped. In this way, the starting point and valve opening time of fuel injection can be controlled. Furthermore, set b4 of MODE register 172 to zero (L)
By doing so, the output of gate 154 and all operations can be stopped. As explained above, according to the present invention, ignition position data based on the control state of intake air to the engine is not directly used for ignition control, but is based on the ignition position where the previous ignition was actually performed. Determine by adding or subtracting the specified value to the value.
Therefore, for the value actually ignited before the above,
The current ignition position will not change beyond the specified limit.
This eliminates sudden changes in the ignition position and smoothes engine torque changes. Furthermore, according to this embodiment, calculation of ignition position data based on the control state of intake air to the engine is performed as a certain period of time elapses. On the other hand, this ignition position data is corrected in synchronization with engine rotation. For this reason, most of the execution time is performed over a certain period of time, and the amount of processing required of the computer is less affected by changes in engine rotation speed, making it stable.This makes it possible to evaluate the ability of the computer. Can be set higher, improving control ability.

[Brief explanation of the drawing]

Figure 1 is an overall system diagram of the engine control system, Figure 2 is a block diagram of the control circuit in Figure 1, Figure 3 is a program system diagram, and Figure 4 is a diagram of the control circuit in Figure 2.
ROM program storage diagram, Figure 5 is a detailed diagram of the initialization (INTIALIZ) program 204 in Figure 3, Figure 6 is a detailed diagram of the monitoring (MONIT) program 206 in Figure 3, and Figure 7 is an ignition timing characteristic diagram. , FIG. 8 is a fuel supply characteristic diagram, FIG. 9 is a characteristic diagram of air bypass control, FIG. 10 is a detailed diagram of the background program 208 in FIG. 3, and FIG. 11 is a diagram of the programs 226, 228 in FIG. 230, FIG. 12 is a detailed diagram of the program 232 in FIG. 3, FIG. 13 is a detailed diagram of the dynamic limitation program (DYNAL) 502 in FIG. 12, and FIG. 14 is a detailed diagram of the program 262 in FIG. 3. 15 is a detailed diagram of the operation of FIG. 11, FIG. 16 is a detailed diagram of the program 242 of FIG. 3, FIG. 17 is a detailed diagram of the program 260 of FIG. 3, and FIG. Figure 19 is an explanatory diagram of the operation in Figure 12, Figure 20 is the program 25 in Figure 3.
2 detailed diagram, Figure 21 is the program 25 in Figure 3.
4 is a detailed diagram, FIG. 22 is an explanatory diagram of the operation of FIG. 21,
FIG. 23 is a characteristic diagram of ignition delay correction, FIG. 24 is a detailed diagram of the program 258 in FIG. 3, FIG. 25 is an explanatory diagram of the operation of FIG. 24, FIG. 26 is a detailed diagram of FIG. 2 is a detailed diagram of the control circuit 156 in FIG. 2, FIG. 28 is a detailed diagram of the control circuit 192 in FIG. 2, and FIG. 29 is a detailed diagram of the control circuit 152 in FIG.
FIG. 30 is a detailed diagram of the operation of FIG. 29. 2...Air cleaner, 4...Turbo charger,
6... Turbine, 8... Compressor, 10... Throttle valve, 12... Accelerator pedal, 14... Air bypass valve, 16... Intake valve, 20... Fuel tank, 22... Filter, 24... Fuel pump,
26...Fuel pressure control valve, 28...Injection valve, 30...Control unit, 40...Battery, 42...Key switch,
44...Ignition coil, 46...Distributor,
50... Spark plug, 49... Piston, 52... Exhaust pipe, 54... Catalyst unit, 56... Muffler, 60...
Bypass passage, 62... EGR valve, 64... Starter motor, 66... Starter switch, 72... Knock sensor, 74... Throttle sensor, 76... Throttle switch, 78... Pressure sensor, 80... Crank angle sensor, 82... Exhaust gas sensor, 102
...CPU, 104...ROM, 106...RAM, 10
8...I/O circuit, 110...Bus line, 126...
Adjustment voltage generator, 122... Voltage sensor, 124...
Atmospheric temperature sensor, 128...Throttle angle sensor, 1
30... Multiplexer, 132... Analog-digital conversion circuit, 134... Register, 136... Analog-digital conversion circuit, 138... Register, 1
42...Top gear switch, 152...Injector control circuit, 154...AND gate, 156...Ignition pulse generation circuit, 140...Angle signal processing circuit,
158...AND gate, 160...AND gate, 1
62...Ignition, 164...Bypass valve control circuit, 166...AND gate, 168...EGR
Volume control pulse generation circuit, 170...AND gate,
172...Mode register, 192...Register, 1
94...Register, 196...Mask register, 19
0...Status register, 204...Initialize program, 206...Monitoring program, 208
...Background job, 224...Interrupt factor analysis program, 226...ADC1 termination program, 2
28... ADC2 termination program, 230... Certain time elapsed interrupt (INTV IRQ) processing program, 23
2...Reference angle interrupt processing program (INTL IRQ),
262... Engine stall processing program, 242... Task scheduler program, 252... Level zero program, 254... Level 1 program, 25
6... Level 2 program, 258... Level 3 program, 256... Completion report program, 802...
Register, 804...Counter, 806...Register, 808...Comparator, 810...Comparator, 812...Flip-flop, 850...Counter, 852...Comparator, 854...Comparator, 586...Flip-flop, 872-886
... Tri-state circuit, 902 ... Register, 90
4...Counter, 906...Comparator, 908...
Flip-flop, 910...AND gate, 91
2...AND gate, 914...register, 916...
Counter, 918...Comparator, 920...Flip-flop.

Claims (1)

[Claims] 1. An intake means for guiding air to be taken into the engine; a throttle valve for controlling the amount of air taken into the engine; and an air-fuel mixture having a predetermined air-fuel ratio based on the control state of the air taken into the engine. a computer that calculates the amount of fuel so as to obtain the desired amount of fuel and further calculates an ignition position suitable for igniting the air-fuel mixture in the combustion chamber of the engine; output means for generating a control signal;
In the apparatus having a fuel supply means and an ignition means for supplying fuel and igniting according to respective control signals, a first ignition position is newly determined according to a control state of air taken into the engine, a first step of performing a process of storing data representing a newly obtained first ignition position in place of data representing the already stored first ignition position every time a certain period of time elapses; a second step of reading stored data representing a first ignition position and correcting this value by a predetermined value in synchronization with the rotation of the output shaft of the engine; A method for controlling ignition timing of an engine, comprising a third step of transmitting ignition position data to the output means in accordance with the value determined in the step.