JPH0672568B2 - Rotational position detection device for internal combustion engine control - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotational position detecting device used for electronic control of an internal combustion engine.

(Prior art and its problems) When the operation of the engine is controlled by an electronic control unit for the internal combustion engine, for example, a fuel injection control unit or an ignition timing control unit, the rotational position of the engine, for example, the crank angle position is accurately detected. However, conventionally, as such a rotational position detecting device, for example, US Pat. No. 4,553,426 is known.

However, the conventional detection device generates a pulse train having unequal intervals in part according to the rotation of the rotating body, detects the predetermined angular position of the rotating body from the generation state of the pulse train, and detects the detected position. Sometimes a reference pulse separate from the pulse train is generated, and the number of pulses in the pulse train generated between the previous generation and the current generation of the reference pulse is counted, and when the pulse count number matches a predetermined number. In addition to discriminating that the count is normal, it is configured to generate a verified reference pulse indicating the normality, so that the high rotation followability of the rotational position detection is not good and the detection result is abnormal. There was a problem that it was not possible to determine immediately.

That is, first of all, when there is a rotational fluctuation in the rotating body such as when the engine rotates due to the operation of the engine, complicated calculation is required to generate the reference pulse, and this calculation process takes time. , The followability at high engine speed is not good.

Next, in order to verify the reference pulse, that is, to determine whether or not the count pulse number of the pulse train is correct, it is necessary to perform the processing such as the reference pulse determination and the pulse train count pulse comparison, so that the verification is performed. A delay time still occurs before the reference pulse is generated, and this effect is greater when the engine speed is higher.

Further, since the determination of whether or not the rotational position is normally detected is made only when the reference pulse is generated, an error occurs in the pulse train count, that is, the rotational position detection, between the two reference pulses. However, this cannot be detected promptly, and the abnormality determination of the detection is delayed.

(Object of the Invention) The present invention has been made in order to solve the problems of the above-mentioned prior art, improves the high rotation followability of the rotational position detection, and enables immediate determination of an abnormality in the detection result.
An object of the present invention is to provide a rotational position detecting device for controlling an internal combustion engine, which is designed to improve the precision of engine control.

(Means for Solving the Problems) In order to achieve the above object, in the rotational position detecting device for controlling an internal combustion engine of the present invention, a plurality of detected parts which are partially unequal in the circumferential direction are provided. A rotating body which rotates with the operation of the internal combustion engine, a pulse generating means for generating a pulse each time the rotating body faces the detected portion according to the rotation of the rotating body, and a measuring means for measuring a time interval of the pulse. And an increase / decrease determination unit that compares the previous value and the current value of the output of the measurement unit and determines increase / decrease thereof, and a storage unit that stores the output of the increase / decrease determination unit as an increase / decrease pattern over a plurality of predetermined sections from the present. And an abnormality determination means for performing abnormality determination by comparing the increase / decrease pattern stored in the storage means with the increase / decrease pattern at the normal time.

(Example) Hereinafter, the Example of this invention is described, referring drawings.

FIG. 1 is an overall configuration diagram of a control device for an internal combustion engine to which a rotational position detecting device according to a first embodiment of the present invention is applied.
In the figure, reference numeral 1 denotes, for example, an internal combustion engine of four cylinders, and there are, for example, seven protrusions (detected portions) 2a on the outer peripheral surface of a crankshaft (rotating body) 2 of the engine 1 at equal intervals of 45 degrees in the circumferential direction. The projecting portion 2b is formed so as to project outward in the radial direction, and the outer peripheral surface other than the projecting portion is a projecting portion 2b in which one projecting portion 2a is missing.

A crank angle position sensor (pulse generation means) 3 (hereinafter referred to as "PC sensor") 3 is arranged at a position facing the protrusion 2a. The PC sensor 3 is composed of, for example, a pickup coil, and generates a crank angle position signal pulse (hereinafter simply referred to as “pulse”) each time it faces the protrusion 2a. Further, the PC sensor 3 is electrically connected to an electronic control unit (hereinafter referred to as “ECU”) 5 via a waveform shaping circuit 4, and the ECU 5 is supplied with a pulse shaped by the waveform shaping circuit 4. To be done.

As will be described later, the ECU 5 constitutes a measuring means, an increase / decrease judging means, a storage means and an abnormality judging means in this embodiment, detects the rotational position of the crankshaft 2, and
It is determined whether or not the detection result is normal.

Further, various sensors 6 for detecting an engine operating state such as an intake pipe internal pressure are connected to the ECU 5, and these detection signals are supplied, and the output side of the ECU 5 is ignited by an ignition circuit 8 via an amplifier circuit 7. And an engine control device such as the fuel injection valve 9 and the like. The ECU 5 calculates the control amount of the engine control device, that is, the energization timing of the ignition device 8 and the valve opening time of the fuel injection valve 9 according to the input signals from the various sensors 6, and outputs the control signal based on the calculation result. , Is supplied to the ignition device 8 and the fuel injection valve 9 via the amplification circuit 7 at a predetermined timing according to the detected rotational position of the crankshaft 2.

Next, the operation of the rotational position detecting device having the above configuration will be described.
FIG. 2 is a time chart showing a pulse generation state by the PC sensor 3. That is, seven pulses are generated each time the crankshaft 2 makes one revolution, the time interval between the pulses corresponding to the protrusion missing portion 2b is larger than that of the other portions, and a pulse train is formed by these pulses. . In addition, the ECU 5 measures the time interval Ts (hereinafter, simply referred to as “time interval”) between the time when the pulse is generated last time and the time when this time is generated by the control program described later, and the previous value of the time interval Ts and this time. When the latter is larger than the former, that is, when the time interval Ts increases, the value 1 is set, and when the latter is smaller than the former, that is, when the time interval Ts decreases, the value 0 is set.

Therefore, it is assumed that the crankshaft 2 rotates clockwise in FIG. 1, and the pulse numbers S of the pulses generated immediately before and immediately after the protrusion missing portion 2b faces the PC sensor 3 are 1 and 2, respectively. If the pulse numbers of the pulses to be generated are sequentially defined as values 3 to 7, assuming that the crankshaft 2 rotates at a constant speed, as shown in FIG. Since the interval is larger than the other time intervals and the other time intervals are equal to each other, the ECU 5 determines that the time interval is increased when the pulse number S = 2, and determines the value 1 when the pulse number S = 3. Then, the value 0 is set respectively, and when the pulse number S is another value, it is determined to be indefinite.

On the other hand, when the engine 1 is operated, the load applied to the crankshaft 2 increases at the end of the compression stroke as shown in FIG. Assuming that the time corresponds to the generation of the pulse of pulse numbers S = 1 and 4, the increase / decrease pattern of the time interval Ts (hereinafter, simply referred to as “increase / decrease pattern”) by the ECU 5 is the pulse number because the generation of the pulse is delayed. S
= 1 to 7, 1 (increase), 1,0 (decrease), 1,0,0 and 1.

That is, since the pulse time interval Ts forms a predetermined increase / decrease pattern during engine operation, this predetermined increase / decrease pattern is stored in advance and the pulse number of the generated pulse is compared by comparing this with the detected increase / decrease pattern, That is, the rotational position of the crankshaft 2 can be detected, and the deviation of the pulse count due to the occurrence of noise or the operation of the PC sensor 3, that is, the abnormality of the detection result of the rotational position can be determined. FIG. 3 shows the increase / decrease patterns for each pulse number when the generated pulses are normally counted, that is, when noise is not generated and the ECU 5 normally counts the pulses from the PC sensor 3. It is a thing.

The execution contents of the control program executed in the ECU 5 will be described below.

FIG. 4 shows a flowchart of a subroutine for initializing the pulse number S and the increase / decrease pattern. This subroutine is executed when the engine 1 is started and when the pulse counter is determined to be abnormal by the subroutine shown in FIG. 6 which will be described later.

First, in step 401, all the stored contents such as the bit pattern P described later are erased, and then the interruption of the subroutine of FIG. 5 described later is prohibited (step 402).

Next, it is determined whether or not a pulse is input (step 40
3) When this answer is affirmative (Yes), that is, when a pulse is input, reset the ts timer composed of an upcounter built in the ECU 5 and start it (step
404). Next, similarly to the step 403, it is determined whether or not a pulse is input (step 405), and when the pulse is input, the ts counter of the ts counter is set as a time interval Ts which is the elapsed time from the pulse input in step 403. The count value ts is set (step 406), and then the ts timer is reset and started similarly to the step 404 (step 40).
7), set temporary pulse number S ₀ to value 1 (step 40)
8).

Next, it is determined whether or not the next pulse is input (step 409), and when the pulse is input, the time interval Ts set in the step 406 is reset to its previous value Ts _-1 (step 410), and a new value is set. Ts as the current value Ts of various time intervals
After setting the count value ts of the counter (step 41
1) Reset and start the ts timer again (step 412).

Next, in step 413, the ratio R between the previous value Ts _-1 and the current value Ts of the time intervals set in steps 410 and 411 is calculated, and then the calculated R value is the maximum value obtained so far.
It is determined whether or not it is larger than MaxR (step 414). When this answer is affirmative (Yes), that is, when R> MaxR is satisfied, the R value at this time is set to the maximum value MaxR and the temporary pulse number S _{0 is set.}
To MaxS ₀ respectively (steps 415 and 41).
6) and proceed to step 417 described below. That is, the maximum value MaxR is R
The maximum value, MaxS ₀ is representative of the provisional pulse number S ₀ at this time. When the answer to step 414 is negative (No), that is, R <MaxR, the process proceeds to step 417.

In this step 417, the bit pattern P stored in the ECU 5 is shifted up by one digit, and then the current value Ts of the time interval is set.
Is smaller than the previous value Ts _-1 (step 41
8). When this answer is affirmative (Yes), that is, when Ts <Ts ₋₁ is satisfied and therefore the current value Ts of the time interval is smaller than the previous value Ts−1, the least significant digit value P _LSB of the bit pattern P is set to the value 0. Set (step 419), negative (No), ie Ts> Ts _-1
Therefore, the current value Ts of the time interval is the previous value Ts _-1
If it is larger than the above, the P _LSB value is set to the value 1 (step 420).

Next, in step 421, the value 1 is added to the temporary pulse number S ₀ , and in step 422, it is determined whether or not the temporary pulse number S ₀ after the addition has reached the value 9. When this answer is negative (No), the process proceeds to step 409. That is, the temporary pulse number S
_The above steps 409 to 421 are repeatedly executed until ₀ reaches the value 9, and the MaxR value, the MaxS ₀ value, the bit pattern P and the temporary pulse number S ₀ are set.

The answer to step 422 is affirmative (Yes), that is, the temporary pulse number.
When S ₀ reaches the value 9, the pulse number S is changed to S = S ₀ −
It is calculated as MaxS ₀ +2 (step 423). As is clear from FIG. 2 (b), the maximum value MaxR is the pulse number S
It is set by executing step 415 when a pulse corresponding to = 3 is generated, but since the addition of the temporary pulse number S ₀ (step 421) corresponding to the pulse generation is performed after the update of MaxS ₀ , From the formula, the temporary pulse number S ₀ is
The pulse number S to be set can be converted and the pulse number S can be correctly assigned to the generated pulse.

Next, in step 424, it is determined whether or not the pulse number S set in step 423 is larger than the value 7, and when the answer is affirmative (Yes), the value is subtracted from the S value to obtain the pulse number S. After resetting to a value less than 7 (step 425),
If negative (No), the process directly proceeds to step 426.

In this step 426, the interrupt-prohibited state for the subroutine of FIG. 5 set in step 402 is released to allow the interrupt, and then the subroutine of FIG. 6 described later is continuously executed (step 427). ) Exit this program. By executing this program as described above, the predetermined pulse number S and the increase / decrease pattern are assigned to the generated pulse when the engine 1 is started or when the abnormality of the pulse count is detected.

FIG. 5 shows a flowchart of a control subroutine for updating the pulse number S and the increase / decrease pattern. This program is synchronized with the pulse generation and is executed by interruption with respect to the subroutine shown in FIG. 6 which will be described later.

First, steps 410 to 4 of the above-mentioned subroutine shown in FIG.
Just like 12, the previous value Ts _-1 and the current value Ts of the time interval are set, the ts timer is reset and started (steps 501 to 503), and then the bit pattern P is shifted to the upper digit by one digit. 504).

Next, the current value Ts of the time interval set in step 502 is the previous value Ts of the time interval set in step 501.
It is determined whether or not it is smaller than s _-1 (step 505), and Ts <Ts
When it is _-1 , the least significant digit value P _LSB of the bit pattern P is set to 0.
When Ts <Ts _-1, the P _LSB value is set to the value 1 (steps 506 and 507) and the increase / decrease pattern is updated.

Then, the value 1 is added to the pulse number S (step 50
8) This is updated, and it is determined whether the updated pulse number S has reached the value 8 (step 509), and when S = 8, the pulse number S is reset to the value 1 (step 509). 510) The program is ended after the S value is ring-counted between 1 and 7.

FIG. 6 shows a flowchart of a pulse count abnormality determination subroutine. This program is repeatedly executed, for example, at regular time intervals, following the subroutine shown in FIG.

That is, this program changes the increase / decrease pattern obtained by the subroutine of FIG. 4 or FIG. 5 into a predetermined increase / decrease pattern that will be obtained at the time of normal counting in correspondence with the pulse number S at this time (see FIG. 3). And the pulse number S is correctly counted when both increase / decrease patterns match. In this embodiment, the lower 8 digits of the bit pattern, that is, the latest 8 pulses are targeted, and converted into hexadecimal display for comparison.

First, in step 601, it is determined whether or not the pulse number S is equal to the value 1. When this answer is affirmative (Yes), that is, when S = 1 holds, the bit pattern in the normal state is P = D3h, as is apparent from FIG. 3, so it is determined in step 602 whether this equation holds. Determine whether. If this answer is negative (No), that is, P = D3h is not established, and therefore the detected increase / decrease pattern of the time interval Ts and the predetermined increase / decrease pattern do not match, it is determined that the count of the pulse number S is erroneous, and the procedure proceeds to step 603. Then, the subroutine shown in FIG. 4 is executed to initialize the pulse number S and the increase / decrease pattern again.

On the other hand, the answer to step 602 is affirmative (Yes), that is, P = D3.
When h is satisfied, since the detected increase / decrease pattern matches the predetermined increase / decrease pattern, it is determined that the pulse number S is normally counted, and the process proceeds to step 604, where the predetermined increase / decrease pattern is determined according to the detected pulse number S. The control signal is output to the ignition device 8 and the fuel injection valve 9 at the timing of
The program is terminated by controlling these.

Similarly, the determination of the step number S and the comparison between the predetermined increase / decrease pattern corresponding to the determined step number S and the detected increase / decrease pattern are performed, and the step 603 or 604 is performed according to the comparison result. Run. That is, when S = 2, P = A7h (steps 605 and 606), when S = 3, P = 4Eh (steps 607 and 608), and when S = 4, P = 9Dh (steps 609 and 606). 610), P when S = 5
= 3Ah (steps 611 and 612), when S = 6, P = 7
4h (steps 613 and 614), or when S = 7, P =
It is determined whether or not E9h is satisfied (steps 615 and 616). When these answers are negative (No), the step 603 is performed, and when affirmative (Yes), the step 604 is performed.
Respectively.

When the answer to step 615 is negative (No), that is, when the pulse number S takes a value other than 1 to 7, the step itself is set to erroneous and step 603 is executed.

As described above, according to the present embodiment, the counting of pulse numbers and the updating of the increase / decrease pattern are executed every time a pulse is generated,
Since the abnormality determination of the pulse count is always performed based on the obtained pulse number and the increase / decrease pattern, it is possible to perform the abnormality determination for each pulse generation, and thus the abnormality of the detection result of the rotational position can be promptly determined. it can. In addition, since it is not necessary to generate a reference pulse, and abnormality determination is performed by comparison calculation of bit patterns that are easy to calculate, the calculation processing time is shortened and the high rotation followability of rotation position detection is improved. In addition to the above, the abnormality in the detection result can be promptly determined.

(Second Embodiment) FIG. 7 is an overall configuration diagram of an ignition timing control device for an internal combustion engine to which a rotational position detecting device according to a second embodiment of the present invention is applied. About the same portion as the first embodiment described above Are given the same reference numerals. The rotational position detection device in this embodiment is different from that in the first embodiment described above in comparison with the crankshaft 2
The main difference is that the number of installations and installation intervals of the projections 2a, the measurement of the time interval of generated pulses, and the determination of increase / decrease thereof are performed by the ECU 5 not for each pulse but for each pulse of a predetermined pulse number.

That is, the outer peripheral surface of the crankshaft 2 is provided with protrusions 2a in the circumferential direction at intervals of 30 degrees, for example, nine protrusions at equal intervals, and three protrusions 2a are missing from the outer peripheral surface other than the protruding portion. It is a protrusion missing portion 2b. The ECU 5 has the same configuration as that of the first embodiment, and the PC sensor 3 is connected to the various sensors 6 via the waveform shaping circuit 4.

The ECU 5 detects the rotational position of the crankshaft 2 by a method described later according to the input pulse from the PC sensor 3 and determines whether or not the detection result is normal. Further, the ECU 5 calculates a control amount such as an ignition timing and an energization timing of the ignition device 8 according to an input signal from the various sensors 6, and an ignition counter 8e and an energization counter 8b described later according to the detected rotational position. Then, the ignition device 8 is controlled to operate at a predetermined timing.

The ECU 5 is an ignition register 8a and an ignition counter 8b of the ignition device 8.
The former 8a sets the ignition timing calculated by the ECU 5, and the latter 8b is composed of an up counter.
The operation is started at a predetermined timing under the control of the ECU 5, and both 8a and 8b are connected to the input side of the first comparator 8c. The first comparator 8c outputs a high level signal when the count value of the ignition counter 8b exceeds the ignition timing set in the ignition register 8a.

Further, the ignition device 8 is provided with an energization register 8d, an energization counter 8e, and a second comparison circuit 8f having the same configuration as the ignition register 8a and the like. That is, the energizing register
8d sets the calculated energization timing, and energization counter 8e
Starts operation at a predetermined timing under the control of ECU5,
The second comparison circuit 8f outputs a high level signal when the count value of the energization counter 8e exceeds the energization timing.

The output sides of the first and second comparators 8c and 8f are respectively connected to the reset terminal R and the set terminal S of the RS flip-flop circuit 8g, and the Q output terminal of the RS flip-flop circuit 8g. Is connected to the ignition coil 8i via the transistor 8h. That is, while the high level signal is being output only from the second comparison circuit 8f, the Q output is at a high level, the energizing power is supplied to the ignition coil 8i, and the high level signal is also output from the first comparison circuit 8c. When the signal is output, the Q output becomes low level and ignition is performed.

Next, the operation of the rotational position detecting device having the above configuration will be described.
FIG. 8 (a) is a time chart showing the state of pulse generation. Nine pulses are generated each time the crankshaft 2 makes one revolution, and the time intervals between the pulses corresponding to the protrusion missing portion 2b are different. These pulses have a value four times that of the portion, and these pulses form a pulse train.

The ECU 5 does not measure the time interval Ts between two adjacent pulses for each pulse generation as in the first embodiment, but measures the time interval Ts between the pulses of the pulse number S detected by the control program described later. Then, the increase / decrease pattern is set based on the measured Ts value.

That is, it is assumed that the crankshaft 2 rotates clockwise in FIG. 1, and the pulse numbers S generated immediately before and immediately after the protrusion missing portion 2b faces the PC sensor 3 are 1 and 2, respectively.
When the pulses to be generated thereafter are sequentially defined as values 3 to 9, the ECU 5 counts the pulses at each pulse generation in this embodiment, but the time interval Ts is measured by the pulse numbers S = 1 to 1.
It is performed only between 2 and 2, 2 and 4, 4 and 8 and 1. Below, the time intervals Ts between the above pulses are Ts ₁ to Ts ₄ respectively.
It is defined as Therefore, when the pulses are normally counted, as shown in FIG.
There is a predetermined increase / decrease pattern of increase (1), decrease (0), increase (1), decrease (0), increase (1), etc. when measuring Ts ₁ , Ts ₂ , Ts ₃ , Ts ₄ , Ts ₁ . can get.

On the other hand, if the count is once increased due to the occurrence of noise or the like and then returns to the state in which the count is performed each time a pulse is generated, the count of the pulse is deviated, but the increase / decrease pattern at this time Is determined by the number of count deviations, and therefore belongs to any of the patterns shown in FIGS. 8 (C-1) to (C-8). For example, when noise is generated only once and this noise is counted as a pulse, the pulse number S is detected with a delay of one (count shift number n =
1), and accordingly, the increase / decrease pattern is set at each time interval Ts ₁ , Ts ₂ ,
It becomes 0,1,1,1 when measuring Ts ₃ and Ts ₄ .

FIG. 9 shows the increase / decrease pattern for each count deviation number n in the same manner as described above, and summarizes this. According to the figure, the increase / decrease pattern of 1,0,1,0 is obtained only when the normal count is performed with respect to the measurement of the time intervals Ts ₁ , Ts ₂ , Ts ₃ and Ts ₄ . By comparing the increase / decrease pattern with the detected increase / decrease pattern, it is possible to determine whether or not the pulse count is normal.

The execution contents of the control program executed in the ECU 5 will be described below.

FIG. 10 is a flowchart of a pulse number S and increase / decrease pattern initialization subroutine that is executed in the same case as the subroutine of FIG.

First, in steps 1001 to 1016, exactly the same execution as steps 401 to 416 of the subroutine of FIG. 4 is performed. Next, in step 1017, the value 1 is added to the temporary pulse number S ₀ , and in step 1018 it is determined whether or not the temporary pulse number S ₀ after the addition has reached the value 10. When this answer is negative (No), the process proceeds to step 1009, and when affirmative (Yes), the pulse number S is calculated as S = S ₀ −MaxS ₀ +2 (step 1
019).

Next, it is judged whether or not the pulse number S set in the step 1019 is larger than the value 9 (step 1020), and when the answer is affirmative (Yes), the value 9 is subtracted from the S value (step 1021), If negative (No), the process directly proceeds to step 1022.

In this step 1022, it is determined whether or not the pulse number S is equal to the value 1 or 4. This answer is affirmative (Ye
s), that is, when S = 1 or 4, the time interval Ts is updated to Ts ₄ or Ts _{2 as} is apparent from FIG.
Since it is when it becomes 1,0 (see FIG. 9), the eight digits are converted into hexadecimal display and set as P = AAh (step 102).
3) Next, the time interval Ts is set to the minimum value 00h that can be set (step 1024), and the process proceeds to step 1031 described later.

When the answer to step 1022 is negative (No), it is determined whether or not the pulse number S is equal to the value 2 or 8 (step 1025). This answer is affirmative (Yes), that is, S =
When 2 or 8 is satisfied, the time interval Ts is updated to Ts ₁ or Ts ₃ and the bit pattern P at the normal count is 0, _{1, 0, 1} , so set P = 55h. (Step 1026) Then, the time interval Ts is set to the maximum value FFFFh that can be set (Step 1027), and the process proceeds to Step 1031 described later.

The answer to step 1025 is negative (No), that is, pulse number S
Is not one of the values 1, 2, 4 and 8, it is determined whether or not a pulse is input (step 1028), the ts timer is reset and started when the pulse is input (step 1029), and then the pulse is input. After the value 1 is added to the number S (step 1030), the process proceeds to step 1020.

In step 1031, fixed ignition control, that is, ignition control that does not respond to the input signals of the various sensors 6, is performed.
The interrupt prohibited state for the subroutine shown in the figure is released (step 1032), the subroutine shown in FIG. 12 to be described later is continuously executed (step 1033), and this program ends.

FIG. 11 is a flow chart of a subroutine for performing pulse number and increase / decrease pattern updating and ignition / energization control, which is executed in synchronization with pulse generation as in the subroutine of FIG.

First, in step 1101, the pulse number S has a value of 1, 2, 4 or 8
It is determined whether or not When this answer is negative (No), it is determined that the pulse number S for updating the increase / decrease pattern does not correspond, the process proceeds to step 1102, the value 1 is added to the pulse number S, and whether or not the S value after the addition is equal to 10 Is determined (step 1103), and when the answer is affirmative (Yes), the pulse number S is reset to the value 1 (step 1104) and negative (No).
In case of, the program is terminated as it is. That is,
When the pulse number S is a value other than 1, 2, 4 and 8, only pulse counting is performed.

When the answer to step 1101 is affirmative (Yes), that is, when the pulse number S is equal to one of the values 1, 2, 4 or 8, steps 1105 to 1111 include steps 501 to 507 in FIG.
Perform exactly the same as above, and measure the time interval Ts and the previous value.
The comparison with Ts ₋₁ and the increase / decrease pattern according to the comparison result are updated.

Next, at step 1112, ignition / energization control is performed. That is, the pulse number S is discriminated and the ignition counter 8c and the energization counter 8f are started at a predetermined timing according to the discrimination result. Next, the steps 1102 to 1104 described above are executed to end the program.

FIG. 12 is a flow chart of a subroutine that is executed in the same way as the subroutine of FIG. 6 and that performs pulse count abnormality determination, ignition / energization timing calculation, and the like.

That is, this program makes an abnormality determination by a calculation for comparing the detected increase / decrease pattern with a predetermined increase / decrease pattern corresponding to the pulse number S at this time.
In this embodiment, when the abnormal count is performed, the time obtained when the time intervals Ts ₁ and Ts _{2 are} measured is the count deviation number n.
However, since the values are 0 and 1 respectively (see FIG. 9), the calculation method for the abnormality determination is, for example, Ts.
₄ At the time of measurement, the updated bit pattern P (4
(Digit) and bit pattern 1100 are ANDed,
Furthermore, the exclusive pattern of this and bit pattern 0100
It is basically determined to be abnormal when the value obtained by taking the OR (XOR) is equal to the bit pattern 0000. This is expressed as the following equation (1).

(PAND1100) XOR0100 = 0000 (1) Note that the equation (1) corresponds to the Ts ₄ measurement, and the bit pattern in the equation (1) when the other time interval Ts is measured.
As 1100 and 0100, those shifted according to the detected time interval Ts are applied. Further, in the actual program, the above formula (1) is applied to eight digits by converting it into hexadecimal display.

First, in step 1201, it is determined whether or not the pulse number S is equal to the value 1, and when the answer is affirmative (Yes), the time interval Ts ₄ has been updated, so (PANDCCh) XOR44h = 0.
It is determined whether or not is satisfied (step 1202). When this answer is affirmative (Yes), that is, when the above equation is satisfied, it is determined that the pulse count is abnormal, ignition is stopped (step 1203), and then the subroutine of FIG. 10 is executed (step 1204). On the other hand, when the answer to step 1202 is affirmative (Yes), that is, when the above equation is not satisfied, it is assumed that the pulse count is normal, and the ignition / energization timing is calculated in step 1205 and thereafter.

That is, in step 1205, the engine speed Ne is calculated from the measured time interval Ts, and then the ignition timing and the energization timing are calculated according to the calculated engine speed Ne and the engine parameter signals from the various sensors 6 ( Step 1206
And 1207), the calculated ignition timing and energization timing are set in the ignition register 8a and the energization register 8d, respectively (steps 1208 and 1209), and this program ends.

Similarly, when the pulse number S = 2 or 3, the time interval Ts ₁ has been updated (PAND99h) XOR88h = 0.
Is satisfied (steps 1210 and 1211), S =
When 4, 5, 6 or 7, (PAND33h) XOR11h = 0 holds (steps 1212 and 1213), or when S = 8 or 9 (PAND66h) XOR22h = 0 holds (PAND66h). Steps 1214 and 1215) are discriminated, and if these answers are affirmative (Yes), the steps 1203 and below are executed, and if they are negative (No), the steps 1205 and below are executed. When the answer to the step 1214 is negative (No), the steps 1203 and thereafter are executed.

As described above, according to the present embodiment, the pulse number is counted for each pulse generation, and the increase / decrease pattern is executed for each pulse corresponding to the predetermined pulse number, and based on the obtained pulse number and increase / decrease pattern. Since the abnormality determination of the pulse count is performed, the abnormality determination can be performed every time a predetermined pulse is generated. Therefore, the high rotation followability of the circuit position detection similar to that of the first embodiment described above can be improved, and The abnormality of the detection result can be promptly determined. Also,
Since the time interval Ts is measured and the increase / decrease pattern is updated for each predetermined pulse, the frequency of the arithmetic processing can be reduced and the simplification can be achieved.

The predetermined pulse for performing the measurement of the time interval Ts is not limited to that shown in this embodiment, and can be set as appropriate, for example, by increasing the setting frequency with respect to the rotational position at which the control is desired to be performed in detail. In this case, a predetermined increase / decrease pattern may be set according to the setting. Further, the operation method for comparing the detected increase / decrease pattern and the predetermined increase / decrease pattern is not limited to the logical operation expression shown in the present embodiment, and other logical operation may be performed depending on the function of the arithmetic unit in the ECU 5. It can be performed in various modes such as by an equation or four arithmetic operations.

(Effects of the Invention) As described in detail above, the present invention stores an increase / decrease pattern of an increase / decrease in the time interval between predetermined pulses of a pulse train generated according to the rotation of a rotating body associated with the operation of an internal combustion engine, and stores the increase / decrease pattern. Since this increase / decrease pattern is compared with a predetermined increase / decrease pattern, it is possible to detect the rotational position for each predetermined pattern and determine the abnormality of the detection result without generating a reference pulse. The high rotation followability is improved, and the abnormality of the detection result can be promptly and accurately determined, so that the accuracy of the engine control can be improved.

[Brief description of drawings]

1 to 6 show a first embodiment of the present invention, FIG. 1 is an overall configuration diagram of a control device for an internal combustion engine including a rotational position detection device, and FIG. 2 is a state of generation of crank angle position signal pulses. FIG. 3 is a diagram showing a pulse time interval increase / decrease pattern in a normal state, FIG. 4 is a flowchart of a subroutine for initializing the pulse number and the pulse time interval increase / decrease pattern, and FIG. 6 is a flow chart of a subroutine for updating the increase / decrease pattern of the pulse time interval, FIG. 6 is a flow chart of a pulse count abnormality determination subroutine, FIGS. 7 to 12 show a second embodiment of the present invention, and FIG. 7 is a rotational position. FIG. 9 is an overall configuration diagram of an ignition timing control device for an internal combustion engine including a detection device, FIG. 8 is a time chart showing states of pulse counts under normal conditions and abnormal conditions, and FIG. Shows a decrease pattern of the normal time and the abnormal time of the pulse time interval, Figure 10 is a flow chart similar to FIG. 4, FIG. 11 is a flow chart similar to FIG. 5,
FIG. 12 is a flowchart similar to FIG. 1 ... internal combustion engine, 2 ... crankshaft (rotating body), 2a
…… Protrusion (detected part), 3 …… Crank angle position (PC)
Sensor (pulse generation means), 5 ... Electronic control unit (ECU) (measurement means, increase / decrease determination means, storage means,
Abnormality determination means).

Claims (4)

[Claims] 1. A rotating body, which comprises a plurality of detected portions which are partially unequal in the circumferential direction, and which rotates with the operation of an internal combustion engine, and each of which faces the detected portion according to the rotation of the rotating body. A pulse generating means for generating a pulse, a measuring means for measuring the time interval of the pulse, an increase / decrease determining means for comparing the previous value and the current value of the output of the measuring means, and determining the increase / decrease, and the increase / decrease Storage means for storing the output of the determination means as an increase / decrease pattern over a plurality of predetermined sections from the present time, and abnormality determination means for performing abnormality determination by comparing the increase / decrease pattern stored by the storage means with the increase / decrease pattern in normal times. A rotational position detecting device for controlling an internal combustion engine, comprising: 2. The storage means converts the output of the increase / decrease determination means into a binary signal, shifts a bit pattern for each output of the increase / decrease determination means, and sequentially stores the new binary signal. The rotational position detection device for controlling an internal combustion engine according to claim 1, wherein the rotational position detection device is configured by: 3. The normal increase / decrease pattern is a bit pattern based on a binary signal that is set according to the installation interval of the detected part and the rotation fluctuation of the rotating body due to the operation of the internal combustion engine. The rotational position detecting device for controlling an internal combustion engine according to claim 2, characterized in that. 4. The comparison of increase / decrease patterns by the abnormality determining means is performed by four arithmetic operations and logical operations between the stored bit pattern and the normal bit pattern. Position detecting device for controlling an internal combustion engine of a vehicle.