JP2015218695A - Electronic controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an engine from being damaged due to a reduction of crank angle signal interval caused by an increase in the number of revolution of the engine, an increased amount of interruption treatment time carried out for every crank angle signal due to addition or improvement of control or occurrence of certain abnormal state at a micro-computer system.SOLUTION: An interruption treatment time carried out for every crank angle signal and an actual period of the crank angle signal are calculated in reference to a starting time and a finishing time of the interruption treatment carried out for every crank angle signal. The measured treatment time is compared with the previous treatment time, and a tolerance degree K is calculated in reference to a degree of increase or decrease of the calculated interruption treatment time. A time in which the tolerance degree K is subtracted from the interruption period is compared with the interruption treatment time and when the interruption treatment time is larger, supplying of fuel is stopped to enable an output of an engine 2 to be restricted.

Description

  The present invention relates to an electronic control device for a vehicle that controls an engine, and more particularly, to an electronic control device for a vehicle that prevents engine damage even when interrupt processing synchronized with a crank angle signal increases.

  The electronic control unit for a vehicle controls the amount of fuel supplied to the engine, the timing of fuel injection, the energization time and ignition timing of the ignition coil, and the amount of air taken in by the engine so that the engine can be operated in an appropriate state. It needs to be controlled in real time. From this, the processing in the vehicle electronic control device is the main processing that repeatedly executes the same processing without depending on the signal from the outside, the interrupt processing that is performed in synchronization with the signal from the outside, and in the device It consists of fixed-time processing that is performed at regular intervals by a timer built in an equipped microcomputer (hereinafter referred to as a microcomputer). In particular, in order to control the timing of fuel injection and the timing of ignition, it is necessary to perform a control operation in interrupt processing synchronized with the crank angle signal. This will be described below.

  The crank angle signal is obtained by reading an output signal of a crank angle signal plate attached to the crankshaft of the engine with a crank angle sensor, and this signal is sent to the electronic control unit. The number of rotations of the crankshaft (physically it should be referred to as the rotation speed, but according to convention, here referred to as the rotation speed) is generally referred to as the engine rotation speed, and is hereinafter referred to as the engine rotation speed. When the engine speed increases, the interval of the crank angle signal decreases in inverse proportion to the engine speed, but the interrupt processing time synchronized with the crank angle signal is almost constant regardless of the engine speed. The ratio of time to the crank angle signal interval increases relatively. For this reason, at the time of high engine rotation, it is necessary to adjust the amount of interrupt processing so that the time is completed within the interval of the crank angle signal.

  For example, in the technique disclosed in Japanese Patent Laid-Open No. 2003-345404 (Patent Document 1), when an interrupt occurs, a plurality of interrupts having different interrupt levels are generated simultaneously. The interrupts (multiple interrupts) that are simultaneously issued are executed in order from the process with the highest interrupt level by the interrupt processing mechanism. The processing to be executed is composed of a plurality of processing units, and the control means sets the processing units to be executed at each interrupt level. As a result, when the interrupt level set for each processing unit becomes an execution target by the interrupt control mechanism, that processing unit is executed. Therefore, the amount of interrupt processing can be adjusted appropriately according to the situation.

  Furthermore, the technique disclosed in Japanese Patent Application No. 2013-126374 related to the application of the present applicant will be described with reference to FIG. FIG. 9 is a graph showing the relationship between the engine speed, the interrupt processing time A synchronized with the crank angle signal, and the crank angle signal period B. The vertical axis represents time [μsec], and the horizontal axis represents engine speed [rpm. ]. Here, the interrupt processing time A indicates the maximum interrupt processing time, and the crank angle signal period B is a crank angle signal period in a 4-cylinder 4-cycle engine. K is a margin of interrupt processing time with respect to the crank angle signal period B, and is a predetermined constant value. C indicated by a broken line indicates a time obtained by subtracting the margin K from the crank angle signal period B. In general, when the interrupt processing time A is longer than the crank angle signal cycle B, there is a fear of engine damage. Therefore, the interrupt processing time A is a time in which a margin K is added to the crank angle signal cycle B. When it becomes longer than C, the fuel cut may be performed.

JP 2003-345404 A

  However, according to the technology disclosed in Patent Document 1, there is a process for calculating water temperature information during the interrupt process synchronized with the crank angle signal. In order to obtain appropriate water temperature information at the interrupt process timing, It is necessary to A / D convert the input value from the water temperature sensor. For this reason, when an abnormality occurs in the A / D converter inside the microcomputer and the A / D conversion processing time is extended, the interrupt processing cannot be completed at the expected time, and is completed within the interval of the crank angle signal. Disappear. As a result, there is a problem that the determination of the crank angle is wrong, fuel control or ignition control is performed on a cylinder that is not the target cylinder, and the engine is damaged in the worst case.

  In the technology disclosed in Japanese Patent Application No. 2013-126374, the margin K is uniquely set from the interrupt processing time synchronized with the crank angle signal and the crank angle signal cycle time. For example, when an increase in interrupt processing time synchronized with the crank angle signal occurs due to the addition or improvement of control for improving the merchantability of the vehicle, such as compliance with exhaust gas regulations and improved drivability performance, the margin K for the crank angle signal period B Thus, the engine speed region in which the interrupt processing time A is longer than the time C in consideration of the above shifts to the lower speed side. Therefore, what was originally cut by the fuel in the region where the engine speed that is rarely used by the driver is 7000 rpm or more must be cut in the practical range, for example, 6500 rpm, and the region of the engine speed used by the driver However, there is a problem that merchantability is impaired due to the inability to use.

  The present invention has been made in view of such a problem, and even when an abnormality occurs in the internal function of the microcomputer, the engine is prevented from being damaged, and the control is added to improve the merchantability of the vehicle such as performance improvement. Even if the interruption processing time increases in synchronization with the crank angle signal and the maximum interruption processing time increases, the vehicle does not cut the fuel in the actual use range of the engine speed of the driver. An object of the present invention is to obtain a vehicle electronic control device that does not impair the merchantability.

  The vehicle electronic control device according to the present invention is a vehicle electronic control device including an interrupt processing unit that controls a fuel injection valve at an interrupt timing synchronized with a crank angle signal from a crank angle sensor. The crank angle detection means for detecting the crank angle signal from the crank angle sensor measures the interval between the crank angle signal detected last time and the crank angle signal detected this time, and interrupts according to the current engine speed. A period measuring means for measuring the processing period, an interrupt processing time measuring means for measuring the interrupt processing time actually taken in the previous interrupt processing period, and an actual in the previous interrupt processing period measured by the interrupt processing time measuring means. Interrupt processing time and the actual interrupt processing time in the previous interrupt processing cycle. A margin calculating means for calculating a time increase / decrease degree, and calculating a margin from the interrupt processing time increase / decrease degree, and the interrupt processing time measured by the interrupt processing time measuring means is measured by the period measuring means. A fuel cut determination means for determining that a fuel cut is to be performed and a crank angle detected by the crank angle detection means when the time calculated by subtracting the margin calculated by the margin calculation means from the interrupt processing cycle Based on the signal, the cylinder determining means for determining whether or not the current interrupt processing cycle is a fuel injection timing, and the cylinder determining means in the current interrupt processing cycle is determined to be the fuel injection timing, When the fuel cut determination means determines that the fuel cut is to be performed, the valve opening time of the fuel injection valve is set to 0, and A fuel output unit for controlling the fuel injection valve, in which with a.

  According to the present invention, the actual interruption processing time is measured, and the margin K is set according to the increase / decrease change of the actual interruption processing time, thereby adding control for improving the merchantability of the vehicle such as performance improvement. Even if the maximum interrupt processing time synchronized with the crank angle signal increases due to improvements or improvements, it will impair the merchantability of the vehicle due to a fuel cut at a unique engine speed that assumes the maximum interrupt processing time. Can be prevented. In addition, even if an abnormality occurs in the A / D converter inside the microcomputer and the A / D conversion processing time suddenly increases, interrupt processing synchronized with the crank angle signal is completed within the interval of the crank angle signal. It is possible to appropriately perform fuel control and ignition control on the target cylinder without erroneously determining the angle, and it is possible to prevent engine damage by appropriately performing fuel cut and ignition timing control.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram of an engine electronic control system to which a vehicle electronic control device according to Embodiment 1 of the present invention is applied. It is a schematic diagram of the control apparatus shown in FIG. It is a block diagram showing the flow of control of the electronic controller for vehicles concerning Embodiment 1 of this invention. It is a flowchart which shows the initialization process of the control program which CPU in the electronic controller for vehicles concerning Embodiment 1 of this invention performs. It is a flowchart which shows the main process of the control program which CPU in the electronic controller for vehicles concerning Embodiment 1 of this invention performs. It is a flowchart which shows the flow of a series of interruption processes in the vehicle electronic control apparatus which concerns on Embodiment 1 of this invention. It is a figure showing the relationship between the interruption process time increase / decrease degree and margin in the vehicle electronic control apparatus which concerns on Embodiment 1 of this invention. It is a figure showing the relationship between the crank angle signal period by the engine speed and interruption processing time in the vehicle electronic control apparatus which concerns on Embodiment 1 of this invention. It is a figure showing the relationship between the engine speed in the prior art, the interruption processing time synchronized with the crank angle signal, and the crank angle signal cycle.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a vehicle electronic control device according to the invention will be described with reference to the drawings.

Embodiment 1 FIG.
First, for convenience of explanation, an engine electronic control system to which the vehicle electronic control apparatus according to Embodiment 1 of the present invention is applied will be described. FIG. 1 is a system diagram of an electronic control system of an engine to which the vehicle electronic control device according to Embodiment 1 is applied.
In FIG. 1, reference numeral 1 denotes a control device. The control device 1 includes a cooling water temperature sensor 3 of the engine 2, an intake pressure sensor 5 provided in the intake pipe 4, a throttle opening sensor 6, an accelerator opening sensor 7, Detection signals from a crank angle sensor 9 that generates 36 high-level signals per rotation and an air-fuel ratio sensor 11 provided in the exhaust pipe 10 are input from a crank angle signal plate 8 that rotates in synchronization with the crankshaft. The Based on these detection signals, output signals are issued to the fuel injection valve 12, the igniter 13, the electronic throttle motor 14 and the like provided in the intake pipe 4, and the engine is controlled. A distributor 16 for sequentially distributing the high voltage generated by the igniter 13 to an ignition plug (not shown) of each cylinder is disposed between the igniter 13 and the ignition coil 15.

FIG. 2 is a diagram illustrating a configuration of the control device 1. The control device 1 includes a microcomputer 20, input interface circuits 21, 22, and 23, an output interface 24, a ROM 25 that stores a control program and data, and the like. The ROM 25 may be built in the microcomputer 20 or may be externally attached as shown in FIG. The microcomputer 20 includes a CPU 26 that performs control calculation according to a control program described later, a counter 27 that functions as a timer, a timer 28 that measures the rotation period of the engine 2, an A / D converter 29, an input port 30, a RAM 31 that functions as a work memory, and the like. And an output port 32 and the like.

  A detection signal from the crank angle sensor 9 is input to the input interface circuit 21. Based on this detection signal, the CPU 26 calculates the rotational speed of the engine 2. The high level signal of the crank angle sensor 9 is also used as an interrupt signal for a control program described later. Detection signals from the coolant temperature sensor 3 and the intake pressure sensor 5 are input to the input interface circuit 22, and various digital signals 33 such as an air conditioner switch are input to the input interface circuit 23. A fuel injection time width pulse is output from the output port 32, and this fuel injection time width pulse is output to the fuel injection valve 12 via the output interface 24. The microcomputer 20 is supplied with power through a power circuit 34, and the RAM 31 is supplied with backup power through a power circuit 35.

  The electronic control system of the engine to which the vehicle electronic control device according to the first embodiment is applied is configured as described above. Next, the vehicle electronic control device according to the first embodiment will be described. FIG. 3 is a block diagram illustrating a control flow of the vehicle electronic control device according to the first embodiment.

  In FIG. 3, reference numeral 40 denotes an interrupt processing unit that inputs a detection signal of the crank angle sensor 9 and executes interrupt processing that is started in synchronization with the detection signal, and reference numeral 41 denotes a main processing unit that executes main processing. Is shown. The interrupt processing unit 40 includes a crank angle detection unit 40a, a cylinder identification unit 40b, a cycle measurement unit 40c, an interrupt processing time measurement unit 40d, a margin calculation unit 40e, a fuel cut determination unit 40f, and a fuel output unit 40g. . The main processing unit 41 includes an engine speed calculation unit 41a, an intake air amount calculation unit 41b, and a fuel injection amount calculation unit 41c.

  The crank angle detection means 40a detects the crank angle signal from the crank angle sensor 9, stores the processing start time Ts stored in the RAM 31 in the previous interrupt processing in the RAM 31 as the previous interrupt processing start time Tso, and this time The time when the crank angle signal is detected is stored in the RAM 31 as the current interrupt processing start time Ts, and the crank angle information is obtained.

  The cylinder identification unit 40b determines the cylinder that is currently in the compression process from the crank angle information obtained by the crank angle detection unit 40a. The cycle measuring unit 40c stores the crank angle signal cycle Tt stored in the RAM 31 in the previous interrupt processing in the RAM 31 as the previous crank angle signal cycle Tto, and the current interrupt processing start time stored in the RAM 31 by the crank angle detecting unit 40a. The current crank angle signal period Tt is calculated from Ts and the previous interrupt processing start time Tso and stored in the RAM 31.

  The interrupt processing time measuring unit 40d stores the interrupt processing time Tw stored in the RAM 31 in the previous interrupt in the RAM 31 as the previous interrupt processing time Two, and the current interrupt processing start time Ts stored in the RAM 31 by the crank angle detecting unit 40a. The current interrupt processing time Tw is calculated from the interrupt processing end time Te described later, and stored in the RAM 31. The margin calculating means 40e calculates the increase / decrease degree Twu of the interrupt processing time from the difference between the current interrupt processing time Tw measured by the interrupt processing time measuring means 40d and the previous interrupt processing time Two, and stores it in the RAM 31. Further, the margin K is calculated from the calculated interruption processing time increase / decrease degree Twu and stored in the RAM 31.

  The fuel cut determination means 40f uses the current crank angle signal period Tt obtained by the period measurement means 40c, the margin K obtained by the margin calculation means 40e, and the current interruption processing time Tw obtained by the interruption processing time measurement means 40d. A comparison is made to determine whether or not to perform a fuel cut. The fuel output means 40g converts the fuel injection amount obtained by the fuel injection amount calculation means 41c, which will be described later, into a time width pulse, and outputs it to the fuel injection valve 12 based on the cylinder information obtained by the cylinder discrimination means 40b. However, the time width pulse is set to 0 when the fuel cut determination means 40f determines that the fuel is cut.

  The engine speed calculation means 41a calculates the engine speed based on the cycle of the crank angle signal obtained by the period measurement means 40c. The intake air amount calculation means 41 b calculates the intake air amount based on the detection signal of the intake pressure sensor 5. The fuel injection amount calculating means 41c calculates the fuel injection amount from the engine speed obtained by the engine speed calculating means 41a and the intake air amount obtained by the intake air amount calculating means 41b.

  FIG. 4 is a diagram illustrating initialization processing of a control program executed by the CPU 26 and is processing executed when the control device 1 is started. When this process is started, first, the operating environment of the microcomputer 20 is set in step (hereinafter simply referred to as S) 100. Next, when the RAM 31 is initialized in S101, the process proceeds to the main process shown in FIG.

  In the main process of FIG. 5, first, in S200, the engine speed is calculated from an interrupt cycle (Ts-Tso) described later. This is processed by the engine speed calculation means 41a of FIG. Next, in S201, the fuel injection amount is calculated based on the detection results of the cooling water temperature sensor 3, the intake pressure sensor 5, and the like. This is processed by the fuel injection amount calculating means 41c in FIG. Based on the calculation result, the valve opening time of the fuel injection valve 12 is controlled.

  Next, the target electronic throttle valve opening is calculated in S202 based on the detection results of the coolant temperature sensor 3, the accelerator opening sensor 7, and the like. The electronic throttle valve motor operation amount is calculated from the calculation result of the target electronic throttle valve opening and the detection result of the throttle opening sensor 6. The electronic throttle motor 14 is controlled based on the calculation result. When the electronic throttle valve motor operation amount is calculated, the process returns to S200, and is repeatedly executed thereafter.

FIG. 6 is a detailed flowchart showing the interrupt processing in the interrupt processing unit 40 in the block diagram shown in FIG.
First, the processing start time Ts stored in the RAM 31 in the previous interrupt processing in S300 is stored in the RAM 31 as the previous interrupt processing start time Tso, and the current interrupt processing start time is set as the current interrupt processing start time Ts. Store in the RAM 31. This is executed by the crank angle detection means 40a.

  Next, in S301, the interrupt cycle (Ts-Tso) is calculated from the previous interrupt process start time Tso and the current interrupt process start time Ts. This is executed by the period measuring means 40c. In S302, the interrupt processing time increase / decrease degree Twu (= Tw−Two) is calculated from the current interrupt processing time Tw and the previous interrupt processing time Two calculated in S313, which will be described later, and stored in the RAM 31. In S303, the margin K is calculated from the interrupt processing time increase / decrease Twu calculated in S302 and stored in the RAM 31. S302 and S303 are executed by the margin calculation means 40e.

In S304, the time obtained by subtracting the margin K from the interrupt cycle (crank angle signal cycle) calculated in S301 is compared with the current interrupt processing time Tw calculated in the previous interrupt processing S313 and stored in the RAM 31. If the current interrupt processing time Tw is equal to or longer than that, the fuel cut flag is set to 1 in S305 and the process proceeds to S306. If the current interrupt processing time Tw is shorter, the process proceeds to S306 as it is. Here, S304 and S305 are executed by the fuel cut determination means 40f.

  Next, in S306, it is determined whether or not the current interrupt process is the fuel injection timing. This is executed by the cylinder discriminating means 40b. If it is determined in S306 that it is not the fuel injection timing, the process proceeds to S312. If it is determined that it is the fuel injection timing, the fuel injection amount obtained in S201 of FIG. 5 is converted into a time width pulse in S307. In S308, it is determined whether or not the fuel cut flag is 1. If the fuel cut flag is 1, the time width pulse is replaced with 0 in S309, and the process proceeds to S310. If the fuel cut flag is not 1, the process proceeds to S310. Move. In S310, the time width pulse set up to S309 is output to the output port 32. In S311, the fuel cut flag is cleared to 0 in preparation for the next interruption process, and the process proceeds to S312. S307 to S311 are executed by the fuel output means 40g.

  In S312, the value of the timer 28 is stored in the RAM 31 as the current interrupt processing end time Te. In S313, the interrupt processing time Tw stored in the RAM 31 in the previous interrupt processing is stored in the RAM 31 as the previous interrupt processing time Two, and is stored in the RAM 31 in S300 and the current interrupt processing end time Te stored in S312. The interrupt processing time is calculated from the current interrupt processing start time Ts and stored in the RAM 31 as the current interrupt processing time Tw. S312 and S313 are executed by the interrupt processing time measuring means 40d. After completion of the interrupt process, the process returns to the main process.

  FIG. 7 is a diagram illustrating the relationship between the degree of increase / decrease in interrupt processing time and the margin in the vehicle electronic control device according to the first embodiment. The margin K increases as the interrupt processing time increase / decrease degree Twu increases. In the figure, Ka is a margin K when the interrupt processing time increase / decrease degree Twu is a, and Kb indicates a margin K when the interrupt processing time increase / decrease Twu is b.

FIG. 8 is a diagram showing the relationship between the crank angle signal period and the interrupt processing time according to the engine speed in the vehicle electronic control device according to the first embodiment. The vertical axis represents time [μsec], and the horizontal axis represents engine speed [ rpm].
An alternate long and short dash line D in FIG. 8 represents an interrupt processing time synchronized with the crank angle signal in a state in which the processing has increased due to control improvement or the like. Here, the interrupt processing time D indicates the maximum interrupt processing time. A solid line B is a crank angle signal period in a four-cylinder four-cycle engine. E and F indicate the time with the allowance K added to the crank angle signal period B. When the margin K in FIG. 7 is Kb, the time obtained by subtracting the margin K from the crank angle signal period is E, and when the margin K in FIG. 7 is Ka, the margin K with respect to the crank angle signal period. The time obtained by subtracting is F.

  As described above, according to the vehicle electronic control device according to the first embodiment, when the increase / decrease degree of the interrupt processing time is small, the margin can be set small, and the engine speed is rotated to 7000 rpm without cutting the fuel. As a result, the merchantability can be improved. Further, when the degree of increase / decrease in the interrupt processing time is large, it is possible to prevent the engine from being damaged by appropriately cutting the fuel before the interrupt processing time exceeds the crank angle signal period by increasing the margin.

  In the above, the vehicular electronic control apparatus according to the first embodiment of the present invention has been described. However, the present invention can be appropriately modified or omitted within the scope of the present invention.

1 control device, 2 engine, 3 coolant temperature sensor, 4 intake pipe, 5 intake pressure sensor, 6 throttle opening sensor, 7 accelerator opening sensor, 8 crank angle signal plate, 9
Crank angle sensor, 10 exhaust pipe, 11 air-fuel ratio sensor, 12 fuel injection valve, 13 igniter, 14 electronic throttle motor, 15 ignition coil, 16 distributor, 20 microcomputer, 21, 22, 23 input interface circuit, 24 output interface, 25 ROM, 26 CPU, 27 counter, 28 timer, 29 A / D converter, 30 input port, 31 RAM, 32 output port, 33 various digital signals, 34, 35 power supply circuit, 40 interrupt processing unit, 40a crank angle detection means 40b cylinder identification means, 40c period measurement means, 40d interrupt processing time measurement means, 40e margin calculation means, 40f fuel cut determination means, 40g fuel output means, 41 main processing section, 41a engine speed calculation means, 41b intake air Quantity calculating means, 41c Fuel injection amount calculating means.

The vehicle electronic control device according to the present invention is a vehicle electronic control device including an interrupt processing unit that controls a fuel injection valve at an interrupt timing synchronized with a crank angle signal from a crank angle sensor. The crank angle detection means for detecting the crank angle signal from the crank angle sensor measures the interval between the crank angle signal detected last time and the crank angle signal detected this time, and interrupts according to the current engine speed. A period measuring means for measuring the processing period, an interrupt processing time measuring means for measuring the interrupt processing time actually taken in the previous interrupt processing period, and an actual in the previous interrupt processing period measured by the interrupt processing time measuring means. Interrupt processing time and the actual interrupt processing time in the previous interrupt processing cycle. Calculates the time increase and decrease degree of the interrupt processing time increase and decrease degree becomes larger, the margin calculation means for calculating a margin to increase the margin, is the interrupt processing time measured by the interrupt processing time measurement means A fuel cut determining means for determining that a fuel cut is to be performed when the time is equal to or longer than a time obtained by subtracting the margin calculated by the margin calculating means from the interrupt processing cycle measured by the period measuring means; Based on the crank angle signal detected by the crank angle detection means, the cylinder discrimination means for determining whether or not the current interrupt processing cycle is the fuel injection timing, and in the current interrupt processing cycle, the cylinder discrimination means When it is determined that it is the fuel injection timing and the fuel cut determination means determines that the fuel cut is to be performed, the fuel injection timing is determined. The opening time of the injection valve is set to zero, the fuel output means for controlling said fuel injection valve, in which with a.

The fuel cut determination means 40f uses the current crank angle signal period Tt obtained by the period measurement means 40c, the margin K obtained by the margin calculation means 40e, and the current interruption processing time Tw obtained by the interruption processing time measurement means 40d. A comparison is made to determine whether or not to perform a fuel cut. The fuel output means 40g converts the fuel injection amount obtained by the fuel injection amount calculation means 41c, which will be described later, into a time width pulse, and outputs it to the fuel injection valve 12 based on the cylinder information obtained by the cylinder discrimination means 40b. However, when it is determined that the fuel cut is determined by the fuel cut determination means 40f, the time width pulse is set to zero .

Next, in S306, it is determined whether or not the current interrupt process is the fuel injection timing. This is executed by the cylinder discriminating means 40b. If it is determined in S306 that it is not the fuel injection timing, the process proceeds to S312. If it is determined that it is the fuel injection timing, the fuel injection amount obtained in S201 of FIG. 5 is converted into a time width pulse in S307. Then, in S308, it is determined whether or not the fuel cut flag is 1. If the fuel cut flag is 1, the time width pulse is replaced with zero in S309, and the process proceeds to S310. If the fuel cut flag is not 1, the process directly proceeds to S310. Move. In S310, the time width pulse set up to S309 is output to the output port 32. In S311, the fuel cut flag is cleared to zero in preparation for the next interruption process, and the process proceeds to S312. S307 to S311 are executed by the fuel output means 40g.

Claims (1)

An electronic control device for a vehicle including an interrupt processing unit that controls a fuel injection valve at an interrupt timing synchronized with a crank angle signal from a crank angle sensor,
The interrupt processing unit
Crank angle detection means for detecting a crank angle signal from the crank angle sensor;
A cycle measuring means for measuring the interval between the crank angle signal detected last time and the crank angle signal detected this time, and measuring an interrupt processing cycle according to the current engine speed;
Interrupt processing time measuring means for measuring the interrupt processing time actually taken in the previous interrupt processing cycle;
The interrupt processing time increase / decrease degree is calculated from the interrupt processing time actually taken in the previous interrupt processing cycle measured by the interrupt processing time measuring means and the interrupt processing time actually taken in the previous interrupt processing cycle, A margin calculation means for calculating a margin from the degree of increase / decrease in interrupt processing time,
When the interrupt processing time measured by the interrupt processing time measuring unit is equal to or longer than the time obtained by subtracting the margin calculated by the margin calculating unit from the interrupt processing cycle measured by the cycle measuring unit. A fuel cut determination means for determining that a fuel cut is to be performed;
Cylinder determination means for determining whether or not the current interrupt processing cycle is fuel injection timing based on the crank angle signal detected by the crank angle detection means;
In the current interrupt processing cycle, when it is determined by the cylinder determining means that the fuel injection timing is reached and the fuel cut determining means determines that the fuel cut is to be performed, the fuel injection valve is opened. And a fuel output means for controlling the fuel injection valve by setting the time to zero.