JPS6319698B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to controlling the rotational speed of an engine in an idle state. The concept of feedback control of engine speed using duty pulse is published in Japanese Patent Application Laid-Open No. 48-21032.
It is disclosed in the publication No. If this idea is to be implemented in a system using a digital computer, two types of comparison functions are required: one for setting the cycle and one for setting the pulse width. Therefore, two comparators are required, making the circuit complicated. SUMMARY OF THE INVENTION An object of the present invention is to provide an idle rotation speed control device that can realize a duty pulse generation circuit for feedback control of engine rotation speed with a simple circuit. A feature of the present invention is that two types of comparison functions necessary to generate a duty pulse for feedback control of the engine's idle speed are realized by a high-speed switching circuit and a comparator commonly used. This simplifies the circuit by requiring only one comparator. Furthermore, timer counters for time measurement can also be used in common, which further simplifies the circuit. In order to assist in understanding the present invention as described in the claims, the following shows the correspondence between the structure of the invention and one embodiment. Note that this correspondence relationship is provided only to aid understanding, and is not intended to limit the invention according to the embodiments.

[Table] Next, embodiments of the present invention will be described using figures. FIG. 1 is a system diagram showing the main configuration of an electronic engine control device. The flow rate of the air taken in through the air cleaner 12 is measured by an air flow meter, and an output QA representing the air flow rate is input from the air flow meter 14 to the control circuit 10. The air flow meter 14 is provided with an intake temperature sensor 16 for detecting the temperature of the intake air, and an output TA representing the temperature of the intake air is input to the control circuit 10. The air that has passed through the air flow meter 14 passes through the throttle chamber 18 and is then
The air is drawn into the combustion chamber 34 of the engine 30 from the manifold 26 via the intake valve 32. The amount of air drawn into the combustion chamber 34 is controlled by varying the opening degree of a throttle valve 20 located within the throttle chamber in mechanical conjunction with the accelerator pedal 22. The opening degree of the throttle valve 20 is determined by detecting the position of the throttle valve 20 by the throttle position detector 24, and the signal QTH representing the position of the throttle valve 20 is detected by the throttle position detector 24.
4 to the control circuit 10. The throttle chamber 18 is provided with an idle bypass passage 42 and an idle adjust screw 44 for adjusting the amount of air passing through the bypass passage 42. When the engine is operating in an idling state, the throttle valve 20 is in a fully closed position. air flow
Intake air from meter 14 flows through bypass passage 42 and is drawn into combustion chamber 34 . Therefore, the amount of intake air during idling operation can be changed by adjusting the idle adjust screw. The energy generated in the combustion chamber is almost determined by the amount of air flowing from the bypass passage 42, so by adjusting the idle adjust screw 44 and changing the amount of air taken into the engine, the engine rotation speed during idling can be adjusted to an appropriate level. can be adjusted to a suitable value. The throttle chamber 18 is further provided with a further bypass passage 46 and an air regulator 48. Air regulator 48 is control circuit 1
The amount of air passing through the passage 46 is controlled in accordance with the output signal NIDL of zero, and the engine speed is controlled during warm-up operation and an appropriate amount of air is supplied to the engine when the throttle valve 20 suddenly changes. Additionally, the air flow rate during idling operation can be changed as necessary. Next, the fuel supply system will be explained. The fuel stored in the fuel tank 50 is sucked into the fuel pump 52 and pumped to the fuel damper 54. The fuel damper 54 absorbs pressure pulsations in the fuel from the fuel pump 52 and sends fuel at a predetermined pressure to the fuel pressure regulator 62 via the fuel filter 56. Fuel from the fuel pressure regulator is fed under pressure to a fuel injector 66 via a fuel pipe 60, and the fuel injector 66 is opened by the output INJ from the control circuit 10 to inject fuel. The amount of fuel injected from the fuel injector 66 is determined by the valve opening time of the injector 66 and the pressure difference between the pressure of the fuel fed to the injector and the pressure of the intake manifold 26 into which the fuel is injected. However, it is desirable that the fuel injection rate from the fuel injector 66 is dependent only on the valve opening time determined by the signal from the control circuit 10. Therefore, the pressure of the fuel fed to the fuel injector 66 is controlled by the fuel pressure regulator 62 so that the difference between the fuel pressure to the fuel injector 66 and the manifold pressure of the intake manifold 26 is always constant. Intake manifold pressure is applied to the fuel pressure regulator 62 via a pressure guiding pipe 64, and when the fuel pressure in the fuel pipe 60 exceeds a certain level with respect to this pressure, the fuel pipe 6
0 and the fuel return pipe 58 are in communication with each other, and the fuel corresponding to the excess pressure is transferred to the fuel tank 50 via the fuel return pipe 58.
be returned to. In this way, the difference between the fuel pressure in the fuel pipe 60 and the manifold pressure in the intake manifold is always kept constant. The fuel tank 50 is further provided with a pipe 68 and a canister 70 for absorbing vaporized fuel gas, and an atmosphere opening 7 is provided during engine operation.
4, and the absorbed vaporized fuel gas is guided to the intake manifold through a pipe 72 and then to the engine 30. As explained above, fuel is injected from the fuel injector, the intake valve 32 opens in synchronization with the movement of the piston 74, and a mixture of air and fuel is introduced into the combustion chamber 34. This air-fuel mixture is compressed and combusted by the spark energy from the spark plug 36, thereby converting the combustion energy of the air-fuel mixture into kinetic energy that moves the piston. The combusted air-fuel mixture is exhausted as exhaust gas from an exhaust valve (not shown) to the atmosphere via an exhaust pipe 76, a catalytic converter 82, and a muffler 86. exhaust pipe 76
is the exhaust gas recirculation pipe 78 (hereinafter referred to as EGR pipe).
A portion of the exhaust gas is guided to the intake manifold 26 through this pipe. That is, part of the exhaust gas is recirculated to the intake side of the engine. This recirculation amount is determined by the valve opening amount of the exhaust gas recirculation device 28. This valve opening amount is the output of the control circuit 10.
Controlled by EGR and further exhaust gas recirculation device 28
The valve position is converted into an electrical signal and input to the control circuit 10 as a signal QE. A λ sensor 80 is provided in the exhaust pipe 76 and detects the mixture ratio of the air-fuel mixture sucked into the combustion chamber 34. Specifically O ₂ sensor (oxygen sensor)
is generally used to detect the oxygen concentration in the exhaust gas and generate a voltage Vλ according to the oxygen concentration. The output Vλ of the λ sensor 80 is input to the control circuit 10.
The catalytic converter 82 is provided with an exhaust temperature sensor 84, and an output TE corresponding to the exhaust temperature is input to the control circuit 10. The control circuit 10 is provided with a negative power terminal 88 and a positive power terminal 90. Further, the control circuit 10 applies the above-described signal IGN to the primary coil of the ignition coil 40 to control the spark generation of the spark plug 36, and the high voltage generated in the secondary coil is transferred to the power distributor 38.
is applied to the spark plug 36 via the combustion chamber 34.
generates a spark for combustion within. More specifically, the ignition coil 40 has a positive power terminal 92.
The control circuit 10 is further provided with a power transistor for controlling the primary coil current of the ignition coil 40. Positive power terminal 92 of ignition coil 40 and negative power terminal 88 of control circuit 10
A series circuit is formed between the primary coil of the ignition coil 40 and the power transistor, and when the power transistor becomes conductive, electromagnetic energy is accumulated in the ignition coil 40, and when the power transistor is cut off, electromagnetic energy is accumulated in the ignition coil 40. The above-mentioned electromagnetic energy is energy with high voltage that is generated by the spark plug 3.
6. The engine 30 is provided with a water temperature sensor 96,
The temperature of engine cooling water 94 is detected, and a signal TW corresponding to this temperature is input to control circuit 10. Further, the engine 30 is provided with an angle sensor 98 that detects the rotational position of the engine, and this sensor 98 generates a reference signal PR every 120 degrees, for example, in synchronization with the rotation of the engine. degree) Angle signal every time it rotates
Generate PC. These signals are input to the control circuit 10. A negative pressure sensor may be used in place of the air flow meter 14 in FIG. A negative pressure sensor 100 indicated by a dotted line in the figure inputs a voltage VD corresponding to the negative pressure of the intake manifold 26 to the control circuit 10. Specifically, a semiconductor negative pressure sensor can be considered as the negative pressure sensor 10. The boost pressure of the intake manifold is applied to one side of the silicon chip, and atmospheric pressure or constant pressure is applied to the other side.
In some cases, a vacuum may be used. With such a structure, a voltage VD corresponding to the manifold pressure is generated due to the piezoresistance effect, etc., and is applied to the control circuit 10. FIG. 2 is an operational diagram illustrating the ignition timing and fuel injection timing with respect to the crank angle of a six-cylinder engine. A represents the crank angle, and a reference signal PR is output from the angle sensor 98 every 120 degrees of crank angle. In other words, the crank angle is 0°,
The reality signal PR is input to the control circuit 10 at every angle of 120°, 240°, 360°, 480°, 600°, and 720°. In the figure, B, C, D, H, H, and G are the first cylinders, respectively.
5th cylinder, 3rd cylinder, 6th cylinder, 2nd cylinder, 4th cylinder
Represents the operation of the cylinder. Further, J1 to J6 represent the opening positions of the intake valves of each cylinder. The valve opening position of each cylinder is the second
As shown in the figure, the crank angle is shifted by 120°. Although the valve opening position and valve opening width differ somewhat depending on the structure of each engine, they are approximately as shown in the figure. In the diagram, A1 to A5 are fuel injector 66
This represents the valve opening timing, that is, the fuel injection timing. The time width JD of each injection timing A1 to A5 represents the valve opening time of the fuel injector 66. This time range
JD can be considered to represent the fuel injection amount of the fuel injector 66. Fuel
Injectors 66 are provided corresponding to each cylinder, and these injectors are connected to the control circuit 10.
They are each connected in parallel to the drive circuit within. Therefore, in response to the signal INJ from the control circuit 10, the fuel injectors corresponding to each cylinder open simultaneously and inject fuel. The first cylinder shown in FIG. 2B will be explained. In synchronization with the reference signal INTIS generated at a crank angle of 360 degrees, an output signal INJ is applied from the control circuit 10 to a fuel injector 66 provided in the manifold or intake port of each cylinder. As a result, fuel is injected for the time JD calculated by the control circuit 10 as shown by A2. However, since the intake valve of the first cylinder is closed, the injected fuel is held near the intake port of the first cylinder and is not sucked into the cylinder.
Next, the reference signal INTIS generated at a crank angle of 720°
In response to this, a signal is again sent from the control circuit to each fuel injector 66, and fuel injection indicated by A3 is performed. Almost simultaneously with this injection, the intake valve of the first cylinder opens, and with this valve opening, the fuel injected in A2 and A3
Both fuels injected in the combustion chamber are sucked into the combustion chamber. The same can be said for other cylinders. In other words, in the 5th cylinder shown in C, when the intake valve is at the opening position J5, the A2
The fuel injected by A3 is inhaled. In the third cylinder shown in D, at the intake valve opening position J3, part of the fuel injected at A2, the fuel injected at A3, and
Some of the fuel injected by A4 is inhaled. A portion of the fuel injected at A2 and a portion of the fuel injected at A4 add up to one injection amount. Therefore, in each intake stroke of the third cylinder, two injection amounts are taken in, respectively. Similarly, in the sixth, second, and fourth cylinders shown in E, H, and G, two injections from the fuel injector are inhaled in one intake stroke. As can be seen from the above explanation, the fuel injection amount specified by the fuel injection signal INJ from the control circuit 10 is half of the fuel required for intake, and is injected into the combustion chamber 34 by two injections from the fuel injector 66. The required amount of fuel can be obtained according to the amount of air. In FIG. 2, G1 to G6 indicate ignition timings corresponding to the first to sixth cylinders. By cutting off the power transistor provided in the control circuit 10, the primary coil current of the ignition coil 40 is cut off, and a high voltage is generated in the secondary coil. This high voltage is generated at the ignition timings G1, G5, G6, G2, and G4, and is distributed by the power distributor 38 to the spark plugs provided in each cylinder. As a result, the first cylinder
5th cylinder, 3rd cylinder, 6th cylinder, 2nd cylinder, 4th cylinder
Each spark plug is ignited in cylinder order, and the fuel/air mixture is combusted. The detailed circuit configuration of the control circuit 10 in FIG.
As shown in the figure. A positive power supply terminal 90 of the control circuit 10 is connected to a positive terminal 110 of the battery, and a voltage VB is supplied to the control circuit 10. The power supply voltage VB is set to a constant voltage PVCC, for example, 5 [V] by the constant voltage circuit 112.
is held constant. This constant voltage PVCC is supplied to a central processor (hereinafter referred to as CPU), random access memory (hereinafter referred to as RAM), and read-only memory (hereinafter referred to as ROM).
Furthermore, the output PVCC of the constant voltage circuit 112 is also input to the input/output circuit 120. The input/output circuit 120 includes a multiplexer 122, an analog/digital converter 124, a pulse output circuit 126, a pulse input circuit 128, a discrete input/output circuit 130, and the like. Analog signals are input to the multiplexer 122, and one of the input signals is input based on a command from the CPU.
is selected and input to the analog-to-digital converter 124. As analog input signals, each sensor shown in FIG. From QA respectively,
Analog signal TW representing engine cooling water temperature,
Analog signal TA representing intake temperature, analog signal TE representing exhaust gas temperature, analog signal QTH representing throttle opening, analog signal QE representing valve opening status of exhaust gas recirculation device, analog signal representing excess air ratio of intake mixture The signal Vλ and the analog signal QA representing the amount of intake air are passed through the filter 132~
144 to multiplexer 122. However, the output Vλ of the λ sensor 80 is input to the multiplexer via an amplifier 142 having a filter circuit. In addition, an analog signal VPA representing atmospheric pressure is input from the atmospheric pressure sensor 146 to the multiplexer. Also, from the positive power supply terminal 90°, resistor 150, 15
Voltage VB is supplied to the 2,154 series circuits through a resistor 160, and the terminal voltage of the series circuit of the resistors is held constant by a zener 148. The values of voltages VH and VL at junctions 156 and 158 between resistors 150 and 152 and resistors 152 and 154 are input to multiplexer 122. The CPU 114, RAM 116, and ROM mentioned above
118 and the input/output circuit 120 are connected by a data bus 162, an address bus 164, and a control bus 166, respectively. Furthermore, from the CPU
A clock signal E is applied to each of the RAM, ROM, and input/output circuit 120, and data is transmitted via the data bus 162 in synchronization with this clock signal E. The multiplexer 122 of the input/output circuit 120 has water temperature TW, intake air temperature TA, exhaust gas temperature TE, throttle opening QTH, exhaust recirculation amount QE, λ sensor output Vλ, atmospheric pressure VPA, intake air amount QA, and reference voltage.
Negative pressure VD is input instead of VH, VL, and intake air amount QA. These inputs are in ROM11
Based on the instruction program stored in 8.
The address of the CPU 114 is specified via the address bus, and the analog input of the specified address is taken in. This analog input is routed from multiplexer 122 to analog-to-digital converter 124.
The digitally converted values are held in registers corresponding to the respective inputs, and are taken into the CPU 114 or RAM 116 as required based on instructions from the CPU 114 sent via the control bus 166. A reference pulse PR and an angle signal PC are input from the angle sensor 98 to the pulse input circuit 128 in the form of a pulse train via a filter 168.
Furthermore, a pulse PS having a frequency corresponding to the vehicle speed is input from the vehicle speed sensor 170 to the pulse input circuit 128 via the filter 172 in the form of a pulse train. The signal processed by CPU 114 is held in pulse output circuit 126. Pulse output circuit 12
The output from 6 is applied to a power amplifier circuit 188, and the fuel injector is controlled based on this signal. Reference numerals 188, 194, and 198 are power amplification circuits that control the primary coil current of the ignition coil 40, the opening degree of the exhaust gas recirculation device 28, and the air regulator 4, respectively.
8 is controlled according to the output pulse from the pulse output circuit 126. The discrete input/output circuit 130 receives signals from a switch 174 that detects that the throttle valve 20 is fully closed, a starter switch 176, and a gear switch 178 that indicates that the tranmission gear is a top gear, and filters 180, 182,184
Receive and hold via. Furthermore, it holds processing signals from the central processor CPU 114.
The signals related to the discrete input/output circuit 130 are signals whose contents can be displayed with one bit.
Next, the power amplifier circuits 196, 200, 20
A signal is sent from the discrete input/output circuit to 2 and 204, respectively, to close the exhaust gas recirculation device 28 and stop the recirculation of exhaust gas, control the fuel pump, display abnormal temperature of the catalyst, Indicates engine overheating. FIG. 4 shows a specific circuit of the pulse output circuit 126. A register group 470 is the reference register group mentioned above, and is used to hold data processed by the CPU 114 or to store data at a predetermined constant level. Holds data that indicates a value. This data is
It is sent from the CPU 114 via the data bus 162. The register to hold is specified using address bus 1.
64, and the above data is input to the designated register and held. The register group 472 is a momentary register group and holds the instantaneous state of the engine and the like. Instantaneous register group 472, latch circuit 476, and incrementer 4
78 exhibits a so-called counter function. The output register group 474 includes, for example, a register 430 that holds the rotational speed of the engine and a register 432 that holds the vehicle speed. These values are obtained by reading the values of instantaneous registers when certain conditions are met. Output register group 47
The data held in CPU 162 is sent to a related register by a signal sent from the CPU via the address bus, and sent from this register to the CPU 114 via the data bus 162. Comparator 480 receives reference data from a selected register of the group of reference registers and instantaneous data from a selected register of the group of instantaneous registers at inputs 482 and 484, respectively, and performs a comparison operation. The comparison result is output from the output terminal 486. The output terminal is set in a predetermined register in the first comparison output register group 502 which functions as a comparison result holding circuit. Furthermore, it is then set in a predetermined register of the second comparison output register group 504. Reference register group 470, instantaneous register group 47
2. Read and write operations of the output register group 474, incrementer 478 and comparator 480
The operations of setting the output to the first comparison output register 502 and the second comparison output register 504 are processed within a certain predetermined time. Further, various processes are performed in a time-sharing manner according to the stage order of the stage counter 572. For each stage, a predetermined register in each of the reference register group 470, instantaneous register group 472, first and second comparison result register groups, and, if necessary, a predetermined register in the output register group 474 is selected. . Also, incrementer 478 and comparator 4
80 is commonly used. FIG. 5 is a diagram for explaining the timing of FIG. 4. A clock signal E is supplied from the CPU 114 to the input/output circuit 120. This signal is shown in A. From this clock signal E, a circuit 574 generates two non-overlapping clock signals φ1 and φ2. This signal is shown in (b) and (c). The circuit shown in FIG. 4 operates according to these clock signals φ1 and φ2. FIG. 5D is a stage signal, which is switched at the rise of the clock signal φ2, and the processing of each stage is performed in synchronization with φ2. In Figure 5
THROUGH indicates that the latch circuit or register circuit is enabled, and indicates that the output of these circuits is dependent on the input. Also
LATCH indicates that these circuits hold certain data and the output of this circuit does not depend on the input. The stage signal shown in D becomes a readout signal for the reference register 470 and the instantaneous register 472, and the contents are read out from a certain selected predetermined register. E and F show the operation of reference register 470 and instantaneous register 472, respectively. This operation is performed in synchronization with the clock φ. The operation of latch circuit 476 is shown in FIG. This circuit enters the THROUGH state when φ2 is at a high level, writes data in a specific register read from the instantaneous register group 472, and clocks φ2.
When 2 becomes low level, it becomes LATCH state. In this way, the data of a predetermined register in the instantaneous register group corresponding to that stage is held. The data held in the latch circuit 476 is
Incrementer 478 not synchronized to clock signal
modified based on external conditions. Here, the incrementer 478 has the following functions based on the signal from the incrementer controller 490. The first function is an increment function that increases the value indicated by the input data by one. Second
The function is a non-increment function, which allows the input to pass through without increasing it. The third function is a reset function, which changes all inputs to data indicating a value of 0. Looking at the data flow of the instantaneous registers, one register in the instantaneous register group 472 is selected by the stage counter 572, and its held data is input to the comparator 480 via the latch circuit 476 and the incrementer 478. Additionally, a closed loop is created from the output of incrementer 478 back to the originally selected register. Therefore, when the incrementer functions to increase data by one, this closed loop functions as a counter. However, in this closed loop, if a situation occurs in which the data of the instantaneous register group is output from a specific selected register while the data is looped around and input, malfunction occurs. Therefore, a latch circuit 476 is provided to cut off the data. The latch circuit 476 enters the THROUGH state in synchronization with clock φ2, while the THROUGH state in which the input is written to the instantaneous register is synchronized with clock φ1. Therefore, data is cut between clocks φ2 and φ1. In other words, even if the value of a specific register in the register 472 is changed, the latch circuit 47
The output of 6 remains unchanged. Comparator 480, like incrementer 476, also operates out of synchronization with the clock signal. The input of the comparator 480 is transmitted through a latch circuit and an incrementer for the data held in one reference register selected from the reference register group 470 and the data held in one register selected from the instantaneous register group. received data. The result of this data comparison is synchronized with clock signal φ1.
It is set to the first comparison result register group 502 which enters the THROUGH state. Furthermore, this data is set in the second comparison result register group 504 which enters the THROUGH state at clock φ2. The output of this register 504 becomes a signal for controlling each function of the incrementer, and a drive signal for the fuel injector, ignition coil, exhaust gas recirculation device, etc. Also, based on this signal, the measurement results of the engine rotational speed and vehicle speed at each stage are written from the instantaneous register group to the output register group 474.
Now, for example, when writing the engine rotation speed, the second signal indicating that a certain period of time has elapsed is
It is held in the comparison result register RPMWBF552,
At the RPM stage in Table 1, which will be described later, data held in the instantaneous register 462 is input to the register 430 of the output register group based on the output of this register 552. At this time, the second comparison result register
If the signal indicating that a certain period of time has elapsed is not held in the RPMWBF 552, the operation of inputting the data held in the register 462 to the register 430 is not performed even in the RPM stage. On the other hand, based on the signal held in the second comparison result register VSPWBF 556, data in the instantaneous register 468 is inputted to the output register 432 as data representing the vehicle speed at the timing of the stage VSP. Writing of data representing the engine rotational speed RPM and vehicle speed VSP to the output register group 474 is performed as follows. In Figure 5,
The stage signal STG is RPM or VSP, and the data in the instantaneous register 462 or 468 is at the high level of the clock φ2, and the latch circuit 476 is activated.
It becomes THROUGH state and is written, and the clock φ
2 becomes low level, the above data becomes
LATCHed. The data held in this way is stored in the register RPMWBF552 or
Based on the signal from the VSPWBF556, the output register group 474 enters the THROUGH state as shown in FIG.
be done. When the CPU 114 reads data held in the output register group 474, the CPU 114 specifies the register via the address bus 164, and the data is taken in in synchronization with the clock signal E shown in FIG. 5A. FIG. 6 shows a generation circuit for the stage signal STG.
Stage counter with signal φ1 from circuit 574
SC570 is counted up, and the outputs C0 to C6 of the stage counter SC570 and the output of the T register in Fig. 4 are input to the stage decoder.
Added to SDC. The stage decoder SDC writes signals 01 to 017 as outputs to the stage latch circuit STGL in synchronization with the clock φ2. The stage latch STGL reset input has a fourth
When the ^20- bit signal GO of the MODE register shown in the figure is input and the ^20- bit GO signal of the MODE register becomes low level, all outputs of STGL become low level and all processing operations are stopped. On the other hand, when the GO signal becomes high level, the stage signal STG is outputted again in a fixed order, and processing is performed based on it. The above stage decoder SDC is READ, ONLY,
This can be easily achieved by using MEMORY etc. The detailed contents of stages 00 to 6F of the stage signal STG, which is the output of the stage latch STGL, are shown in Table 1.

【table】

[Table] First, the general set signal GR is input to the reset terminal of the stage counter SC570 in FIG.
becomes. This general reset signal is sent from the CPU when this control circuit is activated. When clock signal φ2 is input in this state, at the rising edge of φ2,
EGRP stage signal STG is output. EGRP processing is performed based on this stage signal. Next, the stage counter SC570 counts up by one at clock φ1, and INTL of the next stage signal STG is output at clock φ2. INTL processing is performed based on this stage signal INTLSTG. Furthermore, next, a stage signal CYLSTG is output and CYL processing is performed, and next, a stage signal ADV is output and ADV processing is performed. In this way, the stage counter SC570
continues to count up in synchronization with φ1, φ
A stage signal STG is output in synchronization with 2, and processing is performed in accordance with this signal. C0 to C6 of stage counter SC570 are all 1
Then, the stage signal INJSTG is output and INJ
Then, all the processes in Table 1 are completed. The stage counter starts at the next clock signal φ1.
C0 to C6 of SC570 are all 0, and stage signal EGRPSTG is output with clock signal φ2.
STG processing is performed. In this way, the processing in Table 1 is repeated. Table 2 shows the processing contents of each stage shown in Table 1.

【table】

[Table] Output from the stage latch circuit STGL in Figure 6
The STG0 and STG7 signals are circuits for synchronizing the input input from the outside with the internal clock signal of the input/output circuit 120, and the output STG0 is output when all of C0 to C2 of the stage counter SC570 are 0. The output STG7 is the stage counter SC570.
Output when C0 to C2 are all 1. External signals include, for example, a rear reflex signal PR generated in synchronization with engine rotation, an angle signal PC, and a vehicle speed pulse PS generated in synchronization with wheel rotation. The periods of these pulses change greatly, and as they are, they are not synchronized with the clock signals φ1 and φ2. Therefore, it is not possible to determine whether or not to increment at the ADVSTG stage, VSPSTG stage, and RPMSTG stage in Table 1. Therefore, it is necessary to synchronize external pulses, for example pulses from a sensor, and the stages of the input/output circuit. Furthermore, in order to improve detection accuracy, the angle signal PC and vehicle speed signal PS need to be synchronized with the stage with respect to the rise and fall of their input pulses. Reference signal PR
For this, it is sufficient to synchronize it with the rise. Output of stage latch circuit STGL in Figure 6
Create the above synchronized signal using STG0 and STG7 at φ2 timing. The circuit is shown in FIG. Further, the operation timing is shown in FIG. Examples of external input pulses such as sensor output include Koba reference pulse PR, angle signal PC, and vehicle speed signal.
PS is latched by the STG0 output shown in FIG. 6 in latch circuits 600, 602, and 604 shown in FIG. 7, respectively. In Figure 8, A is the clock signal φ2, B is the clock signal φ1, and C and D are the stage signals STG7 and STG.
It is 0. This stage signal is generated in synchronization with φ2, as explained in FIG. The signal shown in E is the output pulse from the angle sensor or vehicle speed sensor and is the reference pulse PR or angle pulse PC.
Alternatively, it indicates the vehicle speed pulse PS, and the generation timing, pulse duty, and period of this signal are irregular, and are inputted regardless of the stage signal. Now, a signal as shown in FIG.
Assuming that the pulses are input to 00, 602, and 604, they are latched by the stage signal STG0 (pulse shown in the figure). Therefore, as shown in FIG. 8, the level becomes high at the time point. Furthermore, since the input signals PR, PC, and PS are at high level in the stage signal STG0 indicated by wo, the latch circuits 600, 602, and 6
The high level is latched at 04 respectively. However, in the stage signal STG0 shown by w, the input signal
Since PR, PC, and PS are at low level, the low level is latched. Therefore, the latch circuit 60
The outputs A1, A2, and A3 of 0,602,604 are as shown in F. Latch circuit 606, 608, 61
0 is output A1, A2, A3 respectively stage signal
It latches at STG7 force, so it starts up from the point indicated by yo. Furthermore, the stage signal STG7 also latches at a high level, so it continues to be at a high level. Therefore, the latch circuits 606, 608, 610
The output signals B1, B2, and B3 are as shown in FIG. The signal A1 and the signal B1 sent through the inverter 608 are input to the NOR circuit 612, and a synchronized reference signal PRS is generated as shown in FIG. This synchronized reference signal PRS
captures the rising edge of the reference signal PR and becomes the pulse width of the stage signals STG0 to STG7. EXCLUSIVELY OR circuits 614 and 616 receive signals A2 and B2, and signals A3 and B3, respectively, and the rising edge of the signals PC and PV generates the signal shown in (i), and the falling edge of the signals PC and PV generates the signal (g). Occur. The duty of signals R and G is the same as the duty shown in C, and the duty of the stage signal STG
Determined by 0 and STG7. In the above explanation, it was determined that the signals PR, PC, and PS were input at the same time with the same duty, but in reality, these signals are not input at the same time and their duties are also different. Furthermore, even when looking at the same signal itself, its period and duty differ each time. However, due to FIG. 7 and the synchronization circuit, the pulse has a constant width. This pulse width is the stage signal STG
It is determined by the time difference between STG 0 and STG7. Therefore, latch circuits 600, 602, 604 and 606, 608, 6
By changing the stage signal applied to 10, the pulse width can be adjusted and changed. This pulse width is determined in relation to the timing of the stages in Table 1. In other words, as shown in Table 1, the INTL stage has a stage counter (C0~
C2, C3 to C6) are allocated in the state of (1, 0), and further allocated to each 8th stage as (1, 1), (1, 2), (1, 3), and so on. Since each stage is set to one microset, an INTL stage is assigned to every eight microsets. In the INTL stage, the angle signal
Since it is necessary to detect the PC and control the incrementer, when the output PC of the angle sensor 98 is applied to the synchronization circuit shown in FIG. Make a pulse and based on this synchronized pulse PCS
Control the incrementer controller in the INTL stage. This synchronized angle signal PCS is also detected in stages ADV and RPM. This stage ADV
The RPM is assigned each time the stage counters C0 to C2 are in the state of 3 and 6 and the values of C3 to C6 count up by one. The assigned stage rotates in a cycle of 8 microsecs. The STG0 signal in Figure 7 is C0 of the stage counter.
~ Output when the value of C2 is 0, while STG7 is C0
Output when the value is ~C27. This output is C3~
Made independently of C6. Therefore, as can be seen from Fig. 8, the synchronized angle signal PCS always has a wide pulse width from a value of 0 to a value of 6 for the stage counter outputs C0 to C2, and this pulse is
Detect with INTL, ADV, BPM and control the incrementer controller. As above, the CYL stage that detects the synchronized reference PRS uses the stage counter outputs C0 to C2.
When the reference pulse PR is input from the angle sensor 98, which is always assigned when the value of is 2, the stage counter is always assigned to this input.
When C0 to C2 are 2, it is necessary for the synchronization reference PRS to appear. The circuit in Figure 7 is STG0 and
Since the pulse width between STG7 is obtained, this detailed report is fully satisfied. Next, the VSP stage for detecting the wheel speed is assigned when the stage counter outputs C0 to C2 always have a value of 5. Therefore, it is sufficient that the synchronized PSS signal is output when the value of C0 to C2 is 5. In the circuit shown in Figure 7, the values of C0 to C2 range from 0 to 6.
This value is satisfied because it reaches the value. In figure 7
Instead of the STG0 signal, create a signal STG4 that always appears when the value of C0 to C2 is 4, and use this signal.
Further, the signal STG6, which is always output when the value of C0 to C2 is 6, may be used instead of the signal of STG7.
In this case, if the signal PS is input, the synchronization signal
For PSS, the value of stage counter output C0 to C2 is 4
and 5, it will always be output. The stage cycle will now be explained.
In Table 1, 128 types of stage signals are generated with stage counter outputs C0 to C6 having values from 0 to 127. When all of these signals are generated, the large cycle is completed and a new large cycle begins again. This large cycle is further composed of 16 small cycles,
This small cycle is composed of eight types of stage signals. This small cycle corresponds to the values of stage counter outputs C0 to C2 from 0 to 7, respectively.
This small cycle is completed in 8 microsecs. The pulse outputs PR, PC, and PS from the sensor are reliably synchronized, and the synchronized pulses PRS, PCS,
In order to reliably generate PSS, it is necessary that the output from the sensor has a pulse width longer than this short cycle. For example, the duty of the angular pulse becomes narrower as the engine rotates faster. For example, at 9000 rpm, it will be about 9 microsecs. Therefore, in order to achieve sufficient synchronization with respect to 9000 revolutions per minute, it is necessary to make this small cycle shorter than this, and in this embodiment it is 8 microsecs. Next, the operation of incrementer 478 shown in FIG. 4 will be explained. A detailed circuit of incrementer 478 is shown in FIG. As mentioned above, this incrementer has three functions: the first function is to increase the input data by a value of 1, the second function is to reset the input data, and the third function is to increase the input data by a value of 1. The function is a function that outputs input data as is. The increment function is performed by the ICNT signal, and the reset function is performed by the IRST signal.
When ICNT signal is high level, increment function, when low level, increment function,
When the IRST signal is high level, it becomes a reset function and the IRST signal has priority over the ICNT signal. The conditions may be selected based on the stage signals commanded by each process. The conditions include synchronized external input and the register group 504 of the second comparison result.
This is the output of Further, the conditions for transferring and writing data to the output register 474 are also similar to the conditions for the incrementer. FIG. 10 is a diagram explaining the processing of the fuel injection signal INJ. Since the start of injection differs depending on the number of cylinders, the register 442 that acts as a CYL COUNTER counts the initial angular pulse INTLD generated from the rear frequency signal PRS.
The result is held as a value related to the number of cylinders.
Compare with CYL pulse 404 and when it is greater than or equal to CYL pulse 404, the first register group 502
CYL FF 506 is set to 1, and CYLBF 508 of the second register group 504 is set to 1. With this CYL BF=1, CYL COUNTER4
42 is reset. Also this CYL BF=1
INJ TIMER450 measures the injection time when
is reset. It is always incremented by time unconditionally, and compared with the INJD register 412 in which the injection time is set, and when it is greater than or equal to the INJD register 412, the INJ FF52 of the first register group
2 is set to 1. Also, 1 is set in INJ BF524 of the second register group. This INJ
When BF=1, incrementing by time is prohibited. This reversed output of INJ BF becomes the fuel injection time width, which becomes the valve opening time of the fuel injector. FIG. 11 is a diagram illustrating processing of signals that control ignition. By the initial angular pulse INTLD,
Register 45 acts as ADV COUNTER
2 and is incremented by the synchronized angle pulse PC being high. Then, compare it with the ADV register 414 that holds the ignition angle from INTLD, and if it is greater or equal, the first register 502
ADV FF 526 is set to 1, and ADV BF 528 of the second register 504 is set to 1. ADVD indicating the rise of ADV BF resets the DWL COUNTER 454, which starts energization, and is incremented when the synchronized angle pulse PC is at a high level. Then, the DWL register 416 that holds the angle at which energization starts from the previous ignition position is compared, and if the angle is greater or equal, the first register 502 is
The DWL FF 530 is set to 1, and the DWL BF 532 of the second register 504 is set to 1. The output of this DWL BF532 becomes the ignition control signal ING1. FIG. 12 is a diagram explaining EGR (NIDL) processing. Since these are all proportional solenoids, they perform duty control. maintain the cycle
Holds EGRP register 418 and on time
There are two EGRD registers 420, and
The TIMER is measured by EGR TIMER456. In processing, during EGRP STG processing, the data held in the EGRP register 418 and EGR TIMER 456 are compared, and if they are greater or equal, 1 is set to the EGRP FF 534 in the first register group 502. Set. Furthermore, the second register group 504
EGRP BF 536 is set to 1. When processing EGRD STG, unconditional non-increment, or EGR with EGRP BF=1.
TIMER 456 is reset. EGRDFF5
38 is the EGRD register 420 and EGR TIMER
456, and if the result is greater than or equal, it is set to 1 and EGRD_BF 540 is set to 1. The inverted output of this EGRD BF540 is the EGR control signal. The operation is similar to NIDL. Figure 13 shows the engine speed RPM (and vehicle speed).
FIG. The measurement method uses a certain measurement time width as RPMW.
It is determined by the TIMER 460 and obtained by counting the synchronized angle pulses PC within that time width. RPMW TIMER460, which measures time width,
is unconditionally incremented and also RPMW
It is reset when BF552=1. RPMW
FF550 is set to 1 because the RPMW register 426 that holds the time width and the RPMW
This is when the TIMER 460 is compared and the result is greater than or equal. RPM COUNTER462 that counted the PC by RPMWD indicating the rise of RPMW BF552
The contents of are transferred to the RPM register 430 of the output register 474 and written. Also, RPMW BF
When 552=1, RPM COUNTER462
will be reset. VSP STG processing is also similar to RPM. Table 3 shows the functions of each register.

【table】

【table】

【table】

【table】

【table】

[Table] Next, a method for setting reference data in the reference register 470 will be explained. Register 402,4
04, 406, and 410 are set when the device of this embodiment is started. Once set, these values do not change. Next, data set in register 408 is performed by program processing. Data INJD representing the opening time of the fuel injector 66 is input to the register 412. This data INJD is determined, for example, as follows. Air flow meter 14 output signal
QA is taken through multiplexer 122 to analog-to-digital converter 124 . Here, it is converted into digital data and held in a register (not shown). The load data TP is obtained from the data representing the intake air amount and the data held in the register 430 in FIG. 4 through calculation processing or information stored in a map form. In addition, intake temperature sensor 1
6. Digitally convert the outputs of the water temperature sensor and atmospheric pressure sensor, and make corrections based on this data and the engine operating status. Let this correction coefficient be K1. Furthermore, the battery voltage is also digitized, and correction is performed according to this data. This correction factor is TS
shall be. Correction is then performed by the λ sensor 80. Let this correction coefficient be α. i.e. data
INJD is the following formula. In this way, the opening time of the fuel injector is determined.
However, the method shown here is just one example, and it is of course possible to define it using other methods. The register 414 contains data representing the ignition timing.
ADV is set. This data ADV is created, for example, as follows. Map-shaped ignition data θIG with the load data TP and rotational speed as factors is held in the ROM 118, and is determined from this map. Furthermore, starting correction, water temperature correction,
Add acceleration correction etc. In this way the data
ADV is created. The register 416 contains data DWL as data for controlling the primary current charging time of the ignition coil.
is set. This data DWL is the above data
It is calculated from the ADV value and the digital value of battery voltage. Data EGRP representing the period of signal EGR and data NIDLP representing the period of signal NIDL are set in registers 418 and 422, respectively. These data are predetermined. Data EGRD representing the energization width of the EGR valve (exhaust gas recirculation device) is set in the register 420. As the energization width increases, the valve opening ratio of the exhaust gas recirculation device increases, and the exhaust gas recirculation rate increases. The data EGRD is, for example, a map state in which the factors are the load data TP and the rotation speed.
18. Furthermore, this data is corrected based on water temperature, etc. Data NIDLD representing the energization width of the air regulator 48 is set in the register 424.
This data is subjected to feedback control such that, for example, the rotational speed of the engine in a no-load state becomes a predetermined rotational speed, and is determined as the amount of feedback. Data RPMW and VSPW representing fixed time periods are set in registers 426 and 428, respectively, when the circuit of this embodiment is activated. In the above explanation, the output of the air flow sensor is used as an input factor to control the fuel injection amount, ignition advance angle, exhaust gas recirculation amount, etc. However, it is possible to use a sensor other than this air flow sensor as a sensor that indicates the state of the intake air. For example, a pressure sensor that detects intake manifold pressure may be used. According to the present invention, since the pulse signals irregularly input to the stage cycle are synchronized, accurate detection can be performed. Furthermore, in the embodiment described above, the stage cycle is divided into a large cycle and a small cycle, so the detection cycle can be shortened depending on the accuracy, and the stage for detecting the synchronization signal can be included in the small cycle configuration. Therefore, accurate detection is possible even at high engine speeds. According to the embodiment described above, a reference register group, an instantaneous register group, and a comparison result holding register group are provided, and each predetermined register of the register group is connected to the comparison circuit based on the stage counter, so that many engine control functions can be achieved. Despite this, the comparison circuit has the effect of being simple. According to the present invention, a duty pulse generation circuit for engine speed feedback control can be realized with a simple pulse.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram showing the positions of sensors and actuators in one embodiment of the present invention, FIG. 2 is an operation explanatory diagram for explaining the operation of FIG. 1, and FIG. 3 is an illustration of the control circuit of FIG. 1. Detailed diagram, Figure 4 is a partial detailed diagram of the input/output circuit in Figure 3, Figure 5 is an explanatory diagram of the operation of Figure 4,
Fig. 6 is a detailed diagram of the stage counter in Fig. 4, Fig. 7 is a detailed diagram of the synchronization circuit, Fig. 8 is an explanatory diagram of the operation of Fig. 7, Fig. 9 is a detailed diagram of the incrementer controller, and Fig. 10 is a detailed diagram of the stage counter in Fig. 4. Figure 11 is a diagram explaining the operation of fuel injection signal processing, Figure 11 is a diagram explaining the operation of ignition timing control, Figure 12 is a diagram explaining the operation of EGR or NIDL processing, and Figure 13 is a diagram explaining the operation of engine rotation speed RPM or vehicle speed VSP detection. It is an operation explanatory diagram. 10...control circuit, 12...air cleaner,
14... Air flow meter, 16... Intake temperature sensor, 18... Throttle chamber, 20...
... Throttle valve, 22 ... Accelerator pedal, 24 ... Throttle position detector, 26 ... Intake manifold, 28 ... Exhaust gas recirculation device, 30 ... Engine, 32 ... Intake valve, 34
... Combustion chamber, 36 ... Spark plug, 38 ... Distributor, 40 ... Ignition coil, 42 ... Bypass passage, 44 ... Idle adjuster screw,
46... Bypass passage, 48... Air regulator, 50... Fuel tank, 52... Fuel pump, 54... Fuel damper, 56... Fuel filter, 58... Fuel return pipe, 60... Fuel pipe, 62... Fuel pressure regulator, 64... Impulse pipe, 66... Fuel injector, 68...
...Pipe, 70...Canister, 72...Pipe, 74...Piston, 76...Exhaust pipe, 78...
...Exhaust gas recirculation pipe (EGR pipe), 80...λ sensor, 82...Catalytic converter, 84...Exhaust temperature sensor, 86...Muffler, 88...Negative power supply terminal, 9
0...Positive power supply terminal, 92...Positive power supply terminal, 94...
... Cooling water, 96 ... Water temperature sensor, 98 ... Angle sensor, PR ... Reference signal, PC ... Angle signal, 110 ... Battery positive terminal, 112 ... Constant voltage circuit (output voltage PVCC), 114 ... (CPU)
Central processor, 116... (RAM) random access memory, 118... (ROM) read-only memory, 120... input/output circuit, 12
2...Multiplexer, 124...Analog-digital converter, 126...Pulse output circuit, 12
8...Pulse input circuit, 130...Discrete input/output circuit, 132...Filter, 134...
Filter, 136...Filter, 138...Filter, 140...Filter, 142...Amplifier,
144... Filter, 146... Atmospheric pressure sensor,
148... Tsuena, 150, 152, 154...
Resistance, 156, 158... Connection point, 160...
Resistor, 162...Data bus, 164...Address bus, 166...Control bus, 168...
... Filter, 170 ... Speed detector, 172
...Filter, 174...Throttle switch (fully closed), 176...Starter switch, 178...
... Gear switch, 180, 182, 184 ... Filter, 186 ... Power amplification circuit (fuel injection),
188...Power amplification circuit (ignition circuit), 194
... Power amplification circuit (EGR), 196 ... Power amplification circuit (EGR OFF), 198 ... Power amplification circuit (NIDLE), 200 ... Power amplification circuit (fuel pump), 202 ... Power amplification circuit (catalyst alarm ), 204... Power amplification circuit (overheat), 206... Fuel pump, 208... Lamp (catalyst alarm), 210... Lamp (overheat),
402...Register, 404...Register, 40
6...Register, 408...Register, 410...
...Register, 412...Register, 414...Register, 416...Register, 418...Register, 420...Register, 422...Register,
424...Register, 426...Register, 42
8...Register, 430...Register, 432...
...Register, 442...Register, 444...Register, 446...Register, 448...Register, 450...Register, 452...Register,
454...Register, 456...Register, 45
8...Register, 460...Register, 462...
...Register, 464...Register, 468...Register, 470...Reference register group (RF0), 4
72...Momentary register group (RF1), 474...Output register group (RF2), 476...Latch circuit,
478...Incrementer, 480...Comparator, 482...Comparator input terminal, 48
4... Comparator input terminal, 486... Comparator output terminal, 490... Incrementer controller, 502... First comparison output register group (FFM), 504... Second comparison output register group (FFS), 506 ...Register (CYL), 508...
...Register (CYL), 510...Register (INTL), 512...Register (INTL), 51
4...Register (INTV), 516...Register (INTV), 518...Register (ENST), 52
0...Register (ENST), 522...Register (INJ), 524...Register (INJ), 526...
...Register (ADV), 528...Register (ADV), 530...Register (DWL), 532
...Register (DWL), 534 ...Register (EGRP), 536 ...Register (EGRP), 53
8...Register (BGRD), 540...Register (BGRD), 542...Register (NIDLP), 54
4...Register (NIDLP), 546...Register (NIDLD), 548...Register (NIDLD), 5
50...Register (PPMW), 552...Register (PPMW), 554...Register (VSPW),
556...Register (VSPW), 570...Stage counter, 572...Stage decoder.

Claims (1)

[Claims] 1. A digital computer outputs a signal representing the feedback control amount so that the engine rotational speed in a no-load state becomes a predetermined rotational speed. Based on this output, a duty pulse is generated in a pulse generation circuit, and the duty pulse is used to drive the actuator. The pulse generation circuit has a first register that holds data representing the pulse period of the duty pulse, a second register that holds data representing the pulse width in each period, and a time register that controls the rotational speed of the engine. a timer counter representing the elapsed time; a comparator commonly used to compare the output of the first register with the output of the timer counter; and the output of the second register with the output of the timer counter; and a high-speed switching circuit. and the output of one of the first and second registers is controlled by the high-speed switching circuit so that the timer counter and the comparator can be commonly used for the outputs of the first and second registers. An engine idle speed control device characterized in that the output of the selected register is input to a comparator.