JP2001207903A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device capable of reducing a processing load and improving precision, starting from a reference position on the back of a crank signal first after starting a system and properly carrying out engine control at the time of misjudgement of the reference position. SOLUTION: An edge interval measuring counter 102 measures pulses separation of a crank signal, and a gradual multiplication counter 104 generates a gradual multiplication signal of integral time frequency until a following pulse in accordance with the current pulse separation. A CPU sets a count value of a counter 105 for guard and a reference counter 107 as a value equivalent to a chipped tooth on the back after taking synchronism of a count value of each of the counters of the counter 105 for guard, the reference counter 107 and an angular counter 108 in a state of the count value of the angular counter 108 initialized when it is judged to be the chipped tooth on the back of every 720 deg.CA of the crank signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device.

[0002]

2. Description of the Related Art An engine control device is a device for controlling fuel injection control, ignition timing control, idle speed control, and the like, and operates an engine in an optimum state. That is, signals from various sensors that detect the engine operating state, such as a crank sensor and an engine water temperature sensor, are transmitted as E.
Input to a CU (Electronic Control Unit) to control the optimal fuel injection amount, injection timing, ignition timing, etc.

Control synchronized with engine rotation such as ignition control and injection control, that is, control synchronized with crank angle, generates a signal such as an ignition pulse when an offset time from a crank edge (edge of a crank signal) elapses. Let's go.

[0004]

However, it is necessary to perform an operation for conversion from angle to time, and there is a demand to reduce processing load and improve accuracy.

The present invention has been made under such a background, and its object is to reduce the processing load and improve the accuracy, and also, at the first time after starting the system, from the reference position behind the crank signal. An object of the present invention is to provide an engine control device that can start and can appropriately perform engine control even when a reference position is determined incorrectly.

[0006]

According to the first aspect of the present invention, a pulse signal having a reference position in the middle of a pulse train at predetermined angular intervals corresponding to the rotation of the crankshaft of the engine is supplied with a pulse interval. The pulse interval is measured by the measuring means, and the multiplied signal generating means generates a multiplied signal of an integral multiple frequency by the next pulse based on the current pulse interval by the pulse interval measuring means. in this way,
By providing a system that generates a multiplied signal at a predetermined angular interval and synchronizes with the engine rotation, an operation for converting from angle to time can be omitted, and processing load can be reduced and accuracy can be improved. .

The guard counter counts up with the pulse of the crank signal to generate a guard value that is an integral multiple of the count value when the multiplied signal is generated, and the reference counter uses the multiplied signal to perform guarding by the guard counter. The angle counter counts up within a range not exceeding the value, and the angle counter counts up within a range not exceeding the count value of the reference counter by an internal clock.

Here, when the first counter setting means determines that the crank signal is at the reference position in the table for each 720 ° CA, the count value of the guard counter is initialized and the count value of the reference counter is initialized. Is set to a value corresponding to the reference position in the table. Further, when the second counter setting means determines that the reference signal is located at the back reference position every 720 ° CA of the crank signal, if the count value of the reference counter at that time is larger than a value corresponding to the back reference position, With the count values of the angle counter initialized, the count values of the guard counter, reference counter, and angle counter are synchronized, and then the count values of the guard counter and reference counter correspond to the reference position on the back. Is set to

That is, when the counter value is larger than the value corresponding to the back reference position at the back reference position at every 720 ° CA of the crank signal, the angle counter is used. After the count values of the respective counters are synchronized in a state where the count values of the counters are initialized, the angle counter counts up within a range not exceeding the count value of the reference counter set to a value corresponding to the back reference position. Therefore, the counter group can be corrected even at the back reference position, whereby it is possible to start from the back reference position at the first time when the system is started, and to correct at the back reference position when the reference position is erroneously determined.

According to the second aspect of the present invention, the first aspect is provided.
In addition to the functions and effects of the invention described in (1), by setting the clear value of the angle counter to a value slightly larger than the current count value of the angle counter, the count value of the angle counter can be immediately initialized.

According to the invention described in claim 3, according to claim 1 of the present invention,
In addition to the functions and effects of the invention described in 2, the drive signal is output even if a count-up operation occurs when correcting the count value of the angle counter when synchronizing the count value of each counter. Can be prevented beforehand.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is embodied in a control device for a multi-cylinder gasoline engine for an automobile. FIG. 1 shows a configuration of an engine control ECU 1 according to the present embodiment.

The engine control ECU 1 includes a microcomputer (hereinafter referred to as a microcomputer) 10, a power supply circuit 20, an input / output circuit 30, and an EEPROM 40. The power supply circuit 20 receives power from the battery 2 and supplies a predetermined voltage to each device in the ECU 1. The microcomputer 10 is a CP
A U11, a ROM 12, a RAM 13, an A / D converter 14, an input / output interface 15, and a timer module 16 are provided. Data is exchanged between these members via a data bus. An EEPROM 40 is connected to the input / output interface 15, and data is exchanged with the EEPROM 40 via the input / output interface 15. The input / output circuit 30 inputs signals from sensors, switches, and the like, and outputs drive signals to injectors (fuel injection valves) and ignition devices. Further, the communication line 3 is connected to the input / output circuit 30, and data is exchanged with another ECU via the input / output circuit 30. The CPU 11 of the microcomputer 10 has a sensor
A signal (data) from a switch or the like and data from the communication line 3 are transmitted to the input / output circuit 30 and the input / output interface 1.
5, various calculations are performed based on the data, and the injectors and the like are driven and controlled via the input / output interface 15 and the input / output circuit 30.

Here, the signal taken by the engine control ECU 1 includes a crank signal from a crank sensor. FIG. 2 shows a crank signal for one engine cycle (720 ° CA). This crank signal is composed of a pulse train at predetermined angular intervals corresponding to the rotation of the crankshaft of the engine, and has a missing tooth portion (reference position portion) from which a pulse is extracted in the middle of this pulse train. In this embodiment, the crank signal has a missing tooth configuration in which two pulses are missing every 60 pulses, and the missing tooth portion appears at 720 CA. In other words, the missing tooth portion from which the pulse was removed in the middle of the pulse train is 36
It has every 0 degree CA. This crank signal is input to the hard crank 100 of the timer module 16 in FIG. 1, and the CPU 11 creates a crank counter based on this signal. Specifically, as shown in FIG. 2, the crank counter counts up when a pulse of a crank signal is input,
It is cleared to 0 at the timing of 120 for one engine cycle (when the second pulse is input after the missing tooth). The count of the missing teeth is corrected when the crank pulse is input after the missing teeth. Here, the count value of the crank counter is corrected at the timing of “119” for the front missing teeth, and the count value is corrected at the timing of “59” for the back missing teeth.

On the other hand, the hard crank 100 provided in the timer module 16 of FIG. 1 is a functional unit for processing the crank signal in a hardware manner. This hard crank 100
Thus, the processing of the crank signal shown in FIG. 2 (determination of missing teeth and generation of an angle signal obtained by dividing the time between crank edges) can be performed in a hardware manner.

FIG. 3 shows the configuration of the hard crank 100. 3, a frequency dividing circuit 101, an edge time measurement counter 102, an edge time storage register 103, a multiplication counter 104, a guard counter 105, a missing tooth determination counter 106, a reference counter 107, and an angle counter 1
08. The signal Pφ from the prescaler is sent to the edge time measurement counter 102 and the multiplication counter 104 via the frequency dividing circuit 101. The signal Pφ is sent to the angle counter 108. Further, the crank signal is sent to the edge time measurement counter 102, the guard counter 105, and the missing tooth determination counter 106.

FIG. 4 is a time chart showing the generation of an angle signal (without missing teeth). FIG. 4 shows an input crank signal, a count value of the edge time measurement counter 102, a stored value of the edge time storage register 103, a count value of the multiplication counter 104, an output signal of the multiplication counter 104 (multiplication clock), and a guard counter 105. The value of n
The double value, the count value of the reference counter 107, the count value of the angle counter 108, and the count value of the missing tooth determination counter 106 are shown.

The edge time measurement counter 102 shown in FIG.
A crank signal is input to measure a time (pulse interval) between crank edges. More specifically, the edge time measurement counter 102 as a pulse interval measurement means is a counter that counts up in a time-synchronous manner as shown in FIG. 4, and measures a time between crank edges (between falling edges of a crank signal). The measured value is multiplied by a factor of 1 / n and transferred (reloaded) to the edge time storage register 103, and this data is also reloaded into the multiplication counter 104 at the same time. In the present embodiment, the multiplication value (n value) is set to “3”.
2 ".

The multiplying counter 104 shown in FIG. 3 generates a multiplied clock obtained by reducing the crank edge time by 1 / n using the time between crank edges measured by the edge time measuring counter 102. Specifically, the multiplication counter 104
As shown in FIG. 4, the count is down-counted in time synchronization, and when it becomes "0", a multiplied clock is generated and the value of the edge time storage register 103 is reloaded. As described above, the multiplying counter 104 as the multiplied signal generating means generates a multiplied signal (multiplied clock) having an integral multiple frequency by the next pulse based on the current pulse interval by the edge time measuring counter 102.

The reference counter 107 shown in FIG. 3 performs a count-up operation by a multiplied clock as shown in FIG.
The angle counter 108 in FIG. 3 counts up with a time synchronous clock (counts with an internal clock). The guard counter 105 is a counter that inputs a crank signal and counts up at the falling edge (pulse) of the crank signal, and uses a value that is n times (multiplied) the value before the count up at the same time when the crank edge is input. The data is transferred to the counter 107. As described above, the guard counter 105 counts up with the pulse of the crank signal, and generates a guard value that is an integral multiple of the count value when the multiplied signal is generated.

Here, as shown in FIG.
7 is the guard value (count value n) transferred from the guard counter 105 when the crank edge is input.
Double) cannot be exceeded. That is, the reference counter 107 counts up within a range that does not exceed the guard value of the guard counter 105 with the multiplied clock. The angle counter 108 counts up only when it is smaller than the count value of the reference counter 107. An angle signal is generated in synchronization with the count up of the angle counter 108. That is, the angle counter 108 counts up within a range not exceeding the count value of the reference counter 107 by the internal clock and outputs an angle signal. Thus, the angle signals are generated by the three counters 105, 107, and 108.

In this embodiment, the internal clock (the signal Pφ from the prescaler) is set to 20 MHz, and the angle counter 108 can operate at a higher speed than other counters. In FIG. 4, at the time of deceleration, as the counting operation of the reference counter 107 and the angle counter 108, the value of the reference counter 107 reaches n times the value of the guard counter 105 before the input of the crank edge. The count-up of 108 is prohibited. As a result, at the time of deceleration, the counting operation of the angle counter 108 is stopped, and the occurrence of an angle signal having a certain value or more is prevented. Also, during acceleration, before the reference counter 107 catches up with the n-times value of the guard counter 105, the n-times value of the guard counter 105 is transferred to the reference counter 107 by the input of the crank edge, and the angle counter 108 It keeps counting up until it catches up with the reference counter 107. As a result, at the time of acceleration, the angle counter 108 counts up after the input of the crank edge, and generates an insufficient angle signal.

The angle signal thus generated is input to a counter (not shown) in the hard crank 100, and ignition / injection control is performed in synchronization with the crank angle using a compare register. That is, by providing a system that generates a multiplied signal at a predetermined angular interval and synchronizes with the engine rotation, the calculation for converting from angle to time can be omitted, and the processing load is reduced and the accuracy is improved (n = If 32, LSB = 0.18
75 ° CA).

The missing tooth judging counter 106 shown in FIG. 3 counts up by a multiplied clock and is cleared to 0 by a crank edge input. Therefore, as shown in FIG. 5, when the input of the crank edge due to the missing tooth is not longer than a predetermined time, the missing tooth determination value is reached, and the missing tooth interrupt signal is generated. Specifically, the missing tooth determination counter 106 compares the count value with the missing tooth determination value and generates a missing tooth interrupt signal at the crank edge after the count value becomes equal to the missing tooth determination value.

The missing tooth interrupt signal may be generated when the count value of the missing tooth determination counter 106 reaches the missing tooth determination value. In the present embodiment, the missing tooth determination value is set to 2.5 times the previous crank edge time.

Next, the engine control E configured as described above will be described.
The operation of the CU (engine control device) will be described. FIG. 5 is a time chart showing a method of correcting a counter for generating an angle signal with missing teeth.

FIG. 6 is a flowchart of the counter correction executed by the CPU 11 for a missing tooth. This process is started by an interrupt due to a crank edge. In FIG. 5, since the time between the crank signal edges is three teeth at the missing tooth position as compared with the place other than the missing tooth, the value of the guard counter 105 is corrected by the crank edge interruption before the missing tooth. It must be added, but this process cannot be performed for the first time after system startup or when an unexpected missing tooth occurs. Therefore, the reference counter 107 and the angle counter 108 are
Does not count up at the point where the value matches the value n times the value of the reference counter 107 (see 119 × in this embodiment) at the timing of t1 in FIG. 32 (multiplication ratio) =
By setting (3808), the angle counter 108 restarts the counting operation and the angle signal is output. At the same time, the guard counter 105 is cleared to 0. In the present embodiment, as shown at the timing t2 in FIG. 5, the input of the second crank edge after the missing tooth corresponds to the zero clear position of the angle counter 108, and the value of the guard counter 105 when the crank edge is input. Is transferred to the reference counter 107, and the value of the guard counter 105 is set to 0 (at the timing of t1) by the crank edge interruption after the previous missing tooth. By doing so, the reference counter 107 is cleared to 0 at the second crank edge after the missing tooth, and the angle counter 108 sets the angle counter clear value (= 120 × 3) at the same timing.
2) is reached and cleared to 0.

That is, when the count value of the guard counter 105 is 0 and the count value of the reference counter 107 is 3808 (= 119 × 32) due to the missing tooth interruption, the CP value is set.
Set is performed in U11. At the second crank edge after the missing tooth, the reference counter 107 and the angle counter 108 are cleared to 0 by the hard crank 100, and these counters are synchronized. That is, n times the value of the guard counter> reference counter> angle counter, and the three counters 105, 107, and 108 are each ready to count up.

As described above, when the tooth missing tooth is interrupted, the CP
By setting the counters by U11 and synchronizing the three counters, initialization after starting the system and correction of occurrence of missing teeth in unexpected places (recovery processing for missing tooth determination abnormalities) Can be performed.

More specifically, in FIG. 6, the CPU 11 determines in step 601 whether or not the value of the crank counter is "119" in the crank edge interrupt.
If so, the process proceeds to step 602 as a crank edge interruption after the missing tooth. After setting the value of the guard counter 105 to “0” in step 602, the CPU 11 sets the value of the reference counter 107 to “3808 (= 119 × 32)” in step 603.

As described above, by setting the settings of the guard counter 105 and the reference counter 107 by the CPU 11 at the crank edge interruption after the missing tooth, the angle counter 108 can be corrected as described above. it can.

FIG. 7 is a time chart in the case of correcting the counter for the back missing teeth (correcting the value of the reference counter 107 so as to increase the value). That is, one cycle (720 °
CA) In a system using a crank signal having two missing teeth generated between two points, the angle counter 108 can be initialized by resetting a counter for generating an angle signal and correction when a missing tooth determination is missed. Initialization timing (missing tooth position in the table), that is, in a system in which one cycle of the engine (720 ° CA) is performed with two rotations of the crankshaft, it can be performed only once at a specific missing tooth position during two rotations of the crankshaft. . Specifically, in order to generate a correct angle signal, it is necessary for the three counters 105, 107, and 108 to count up while synchronizing. In other words, if synchronization is not achieved, the angle signal will be abnormal because the angle counter 108 stops or keeps counting up. Therefore, as shown in FIG. 2, the crank counter is cleared to 0 at the time of input of the crank edge two teeth behind the missing tooth.
The timings of 107 and 108 are also initialized at this timing to synchronize them, thereby performing initialization of the system and correcting for missing tooth determination error. In other words, the correction can be performed only on the missing teeth. Therefore, in the present embodiment, the following processing is performed.

In FIG. 7, the angle counter 108 stops due to an unexpected missing tooth as in the case of the front missing tooth in FIG. At this time, in the case of FIG. 7, the set value of the missing teeth of the guard counter 105 and the reference counter 107 (59 × 32 = 1888 in the present embodiment) is on the side larger than the current value. By correcting the 105 and the reference counter 107 to the set value of the missing teeth, the angle counter 108 starts moving again and can return to normal. That is, when the counter is set by the CPU 11 at the time of the back missing teeth, when the reference counter 107 is corrected to be increased, the reference counter 107 and the guard counter 105 are set to the same value as the correction for the front missing teeth.
I'll set it at U11. Specifically, t10 in FIG.
The CPU 11 sets the reference counter 107 to “59 × 32” and sets the guard counter 105 to “60” at the timing of (1). As a result, n times the guard counter> reference counter> angle counter, and the three counters 105, 107, and 108 are synchronized and each can be counted up. Therefore, the angle counter 108 counts up in time synchronization (generates an angle signal) during the period T11 in FIG.

However, as shown in FIG. 8, when the guard counter 105 and the reference counter 107 are corrected to a value smaller than the current value, the reference counter 107 becomes smaller than the angle counter 108, so that the angle counter 10 becomes smaller.
8 cannot start moving. That is, in FIG. 8, when the counter is set by the CPU 11 at the time of the back missing teeth, when the reference counter 107 is corrected to a smaller side, similarly to the correction for the front missing teeth, the reference counter 107 is corrected.
And the guard counter 105 are set by the CPU 11 (in FIG. 8, the reference counter 10
When 7 is set to “59 × 32” and the guard counter 105 is set to “60”, the reference counter <the angle counter, and the angle counter 108 stops (the angle signal cannot be generated).

For this purpose, the CPU 11 executes the processing shown in FIG. 10 to perform the operation shown in FIG. FIG.
At the timing of t30, the value of the guard counter 105 is cleared to 0 by the CPU 11 and the angle counter clear value is set to a value obtained by adding a predetermined value α to the current value of the angle counter 108, and the angle counter clear value is set. It is set in the reference counter 107. Here, the α value is a margin value in which counting is expected to proceed due to data reading / transfer of the microcomputer (a margin value in anticipating counting up from reading of the counter to writing of the register). Thus, the reference counter 107
Is set as the angle counter clear value, the relationship of reference counter> angle counter can be maintained, and the counting up of the angle counter 108 can be prevented from being stopped. Further, by setting the angle counter clear value to a value obtained by adding a predetermined value α to the current angle counter value, the angle counter 10
8 is cleared to 0 by the hard crank after α. When the angle counter becomes 0 (after the three counters are synchronized), the CPU 11 sets the reference counter 107 and the guard counter 105 to the set positions of the back missing teeth. The angle counter 108 keeps counting up to the value of the reference counter 107 in a time-synchronized manner, and after the coincidence, normal processing can be performed.

Specifically, after setting the angle counter clear value to the reference counter 107 at the timing of t30 in FIG. 9, it is confirmed that the angle counter 108 has become "0" and set to "59.times.32". (Indicated by t31 in the drawing), and after the guard counter 105 is set to "0" at the timing of t30, it is confirmed that the angle counter 108 is set to "0", and is set to "60" (FIG. And t32). Therefore, after the count value of the angle counter 108 reaches the angle counter clear value and is cleared to 0 by hardware, the reference counter> the angle counter in the period of T33 in FIG. 9, and the angle counter 108 counts up in time synchronization. (An angle signal is generated). In this way, the three counters 105, 107, and 108 are synchronized, and the system can be activated at the tooth missing.

More specifically, in the processing flow of the tooth missing interrupt in the correction of the angle signal at the time of the tooth missing shown in FIG. 10, the CPU 11 determines whether or not the crank counter is "59" in step 1001. Then, the CPU 11 determines that “59” is a crank edge interrupt after the back missing tooth and determines in step 1002 that the reference counter 107
Is greater than or equal to “59 × 32”. Then, the CPU 11 sets the reference counter> (59 × 3
In the case of 2), it is determined that count synchronization as shown in FIG.

As described above, steps 1001 and 1002
To confirm that the missing teeth and the reference counter> 59 × 32. The CPU 11 sets the guard counter 105 to “0” in step 1003, and
At 004, the next injection timing and ignition timing are initialized.
The initialization of the injection / ignition timing is a process for preventing an angle signal from being generated by counting up of the angle counter 108 while synchronizing the counter, thereby preventing erroneous ignition or erroneous injection. The position and the ignition position are set to the maximum value of the angle counter 108 (for example, a hexadecimal FFF).
F) so that there is no coincidence with the angle counter 108.

The CPU 11 clears the angle counter 108 in step 1005, that is, sets a value obtained by adding a predetermined value α to the current count value. Further, the CPU 11 stores the angle counter 1 in the reference counter 107 in step 1006.
A clear value of 08 is set, and in step 1007, the process stands by until the current count value of the angle counter 108 becomes “0”.

Then, the CPU 11 sets “60” in the guard counter 105 in step 1008, and sets “59 ×” in the reference counter 107 in step 1009.
32 ". As described above, when the value of the reference counter 107 is larger than “59 × 32”, the processing as shown in FIG. 9 is necessary, so that the angle counter 108 is cleared to 0 as in steps 1003 to 1009 to synchronize the counters. Take.

If the value of the reference counter 107 is smaller than "59 × 32" in the step 1002 (in the case of FIG. 7), the process proceeds to the step 1008, where the guard counter 105 and the reference counter 107 are set by the CPU 11.

By such processing, it is possible to initialize the system with a missing tooth and to restart when a missing tooth determination error occurs from the missing tooth. As described above, when the count value of the reference counter 107 is set to the large side as shown in FIG. 7, the processing of steps 1003 to 1007 is unnecessary, and when the count value of the reference counter 107 is set to the small side as shown in FIG. Is used in step 1003 to synchronize the counters.
To 1007 are executed.

As described above, this embodiment has the following features. (A) The CPU 11 as the first and second counter setting means executes the processing in FIG. 6 to determine that the crank signal is a missing tooth (reference position portion in the table) at every 720 ° CA. At the same time, the count value of the guard counter 105 is initialized and the count value of the reference counter 107 is equivalent to the missing tooth position in the table (corresponding to the reference position in the table).
Set to the value of. By executing the processing in FIG. 10, the CPU 11 determines that there is a back missing tooth (back reference position portion) at every 720 ° CA of the crank signal, and the count value of the reference counter 107 at that time is changed to the back. If the value is larger than the value of the missing tooth (corresponding to the reference position on the back), the guard counter 105, the reference counter 107, and the angle counter 108 with the count value of the angle counter 108 initialized.
After synchronizing the count values of the respective counters, the count values of the guard counter 105 and the reference counter 107 are set to values corresponding to the back missing teeth (corresponding to the back reference position).

That is, when the count value of the reference counter 107 at that time at the back reference position every 720 ° CA of the crank signal is larger than the value corresponding to the missing tooth at the back, the angle of the counter is corrected. After synchronizing the count value of each counter with the count value of the counter 108 initialized, the angle counter 108 counts within a range not exceeding the count value of the reference counter 107 set to a value corresponding to the missing tooth on the back. Up. Therefore, it is possible to correct the counter group even with the missing tooth on the back, and thereby, it is possible to start from the missing tooth on the back at the first time when the system is started, and
Correction can be made with a missing tooth on the back when a missing tooth is determined incorrectly.
(B) The CPU 11 performs steps 1005 and 10 in FIG.
When the count value of each counter is synchronized by executing step 06, the clear value of the angle counter 108 is made slightly larger than the current count value of the angle counter, and the count value of the reference counter 107 is cleared. Since the value is set to the value, the count value of the angle counter 108 can be immediately initialized. (C) CPU 11
Performs a guard so that a drive signal is not erroneously output when synchronizing the count values of the respective counters by executing step 1004 in FIG. 10, so that when synchronizing the count values of the respective counters, Therefore, even if a count-up operation occurs when correcting the count value of the angle counter 108, it is possible to prevent a drive signal from being output.

In the above description, the reference position portion of the crank signal is a missing tooth portion from which a pulse is extracted in the middle of a pulse train. However, the present invention is not limited to this. (A structure such as insertion), a reference position portion having unequal pulse intervals may be formed in the middle of a pulse train at predetermined angular intervals.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an engine control ECU according to an embodiment.

FIG. 2 is a time chart showing a crank signal for one cycle of an engine (720 ° CA) and a count value of a crank counter.

FIG. 3 is a configuration diagram of a hard crank.

FIG. 4 is a time chart for explaining generation of an angle signal by a hard crank.

FIG. 5 is a time chart for explaining correction of an angle signal at the time of a missing tooth.

FIG. 6 is a flowchart for explaining correction of an angle signal at the time of a missing tooth.

FIG. 7 is a time chart for explaining correction of an angle signal at the time of back missing teeth.

FIG. 8 is a time chart for explaining correction of an angle signal at the time of back missing teeth.

FIG. 9 is a time chart for explaining correction of an angle signal at the time of back missing teeth.

FIG. 10 is a flowchart for explaining correction of an angle signal at the time of back missing teeth.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine control ECU, 10 ... Microcomputer, 11 ... CP
U, 16: timer module, 100: hard crank, 102: edge time measurement counter, 104: multiplying counter, 105: guard counter, 106: missing tooth determination counter, 107: reference counter, 108: angle counter.

Claims (3)

[Claims] 1. A reference position portion is provided in the middle of a pulse train at predetermined angular intervals corresponding to rotation of a crankshaft of an engine.
° A pulse interval measuring means for measuring a pulse interval by inputting a crank signal provided for each CA, and generating a multiplied signal of an integral multiple frequency by the next pulse based on the current pulse interval by the pulse interval measuring means. Signal generating means, a counter for counting up by a pulse of the crank signal and generating a guard value of an integral multiple of the count value when generating the multiplied signal, and a guard for the guard by the multiplied signal. A reference counter that counts up within a range not exceeding the guard value of the counter; an angle counter that counts up within a range that does not exceed the count value of the reference counter using an internal clock;
A first counter setting for initializing the count value of the guard counter and setting the count value of the reference counter to a value corresponding to the reference position of the table when it is determined that the reference position is a reference position in the table for each 0 ° CA; Means for determining the count value of the angle counter when the count value of the reference counter at that time is larger than a value corresponding to the reference position of the back when it is determined that the reference position is at the back of the crank signal at every 720 ° CA. After the counter values of the guard counter, the reference counter, and the angle counter are synchronized in a state in which the counter is initialized, the count values of the guard counter and the reference counter are set to a value corresponding to the reference position on the back. And a counter setting means. 2. The second counter setting means sets the angle counter clear value to a value slightly larger than the current angle counter count value when synchronizing the count values of the respective counters, and sets a reference counter value. 2. The engine control device according to claim 1, wherein the count value is set to an angle counter clear value. 3. The apparatus according to claim 1, wherein said second counter setting means guards against erroneous driving signals when synchronizing the count values of the respective counters. An engine control device according to item 1.