JPS6175209A - Apparatus for detecting rotary angle position of internal-combustion engine - Google Patents

Abstract

PURPOSE:To accurately detect a position even if noise is superposed, by judging that the count value of the signal of a rotary angle sensor was changed from a first set value to a second value prior to the generation of a reference position signal and, at the time of judgment, matching said change with the generation time of the reference position signal. CONSTITUTION:Position signals C1-C12 at every 30 deg.-rotation of an engine and upper dead point signals G1, G2 with phase difference of 360 deg. at every 270 deg.-rotation are outputted from a crank angle sensor and the count value of a counter is set to +1 every when the signals C1-C12 are applied and, when the count value is 12, the count value, to which the signal C1 is applied, is set to '1'. Further, when the count value changes from '12' to '1' prior to the change from '12' to '1' prior to the application of the signals G1, G2, a flag F1 coming to zero by the application of the signals G1, G2 is provided and, when the flag F1 is '1', the superposition of noise is judged to set the count value to '1' at the point of time, when the signals G1, G2 are applied, regardless of the count value.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a rotation angle position detection device for an internal combustion engine.

Conventional Technology In order to control fuel injection timing and ignition timing in an internal combustion engine, it is necessary to detect the rotational angular position of the internal combustion engine. The angular position of rotation is detected.

The crank angle sensor outputs rotation angle position signals C1-C12 and top dead center signal Gl as shown in FIGS. 5(A) to (C), for example.
, G2. Rotation angle position signal 01
~C12 is output every time the internal combustion engine (crankshaft) rotates by a certain angle (30° CA in this case),
Top dead center signal G1. Each G2 has a 720 internal combustion engine.
°C^ Output every time it rotates, the phase is 360 degrees from each other
C^ They are different.

Conventionally, the output signal of the rank angle sensor is used to detect the rotational angular position of the internal combustion engine in the following manner. That is, rotation angle position signals 01 to C12
is added, the count value is increased by 1, and the top dead center signal Gl
, when G2 is added, and when the rotation angle position signal is added when the count value is 42, the count value is set to 1.
A counter is provided which is preset to ``, and the rotational angular position of the internal combustion engine is detected based on the counter value of the counter. For example, if the signals shown in FIGS. 5(A) to 5(C) are applied to the counter, the count value of the counter corresponds to the rotational angular position of the internal combustion engine as shown by the solid line in FIG. 5(D). Therefore, the rotational angular position of the internal combustion engine can be detected based on the count value of the counter.

However, the conventional example described above has the following six drawbacks.

That is, when noise is superimposed on the top dead center signal Gl or the top dead center signal G2, there is a drawback that the count value of the counter and the rotational angular position of the internal combustion engine do not correspond. For example, when noise (A) is superimposed on the top dead center signal G2 as shown in FIG. 5(C), the count value of the counter is as shown by the dotted line in FIG. There is a drawback that the count value of the counter does not correspond to the rotational angular position of the internal combustion engine until the top dead center signal G2 is applied.

In order to solve this problem, the count value is incremented by 1 each time the rotation angle position signals 01 to CI2 shown in FIG. 5(A) are added, and when the count value is "12", the rotation angle position signal is added. When the count value is 42'', the same figure (
B), top dead center signal G1 shown in (C). Conventionally, it has been proposed to provide a counter that sets a count value to "1" when G2 is applied, and to detect the rotational angular position of the internal combustion engine based on the count value of the counter. By using a counter with such a configuration, even when noise is superimposed on the top dead center signal Gl or the top dead center signal G2, the count value of the counter and the rotational angular position of the internal combustion engine can be matched. It is possible to do so. For example, even when noise (A) is superimposed on the top dead center signal G2 as shown in FIG. Since the count value of the counter is not preset to "1" by (a), the count value of the counter corresponds to the rotational angular position of the internal combustion engine, as shown by the solid line in FIG.

However, the conventional example described above has the following drawbacks.

In other words, when noise is superimposed on the rotational angular position signals 01 to C12, if the count value of the counter and the rotational angular position of the internal combustion engine do not correspond semi-permanently, the counter will be The counter value is counted up from "9" to "lO" as shown by the dotted line in FIG. There is a drawback that the rotation angle position of the engine is semi-permanently shifted by 30° CA. That is, when the top dead center signals Gl and G2 are generated, the count value of the counter is "1" and the top dead center signals Gl and G2 are ignored, so the count value of the counter and the internal combustion engine are There was a drawback that the rotation angle position was semi-permanently shifted by 30° CA.

Problems to be Solved by the Invention The present invention improves the above-mentioned drawbacks, and its purpose is to improve the rotation of the internal combustion engine even when noise is superimposed on the rotation angle position signal or the top dead center signal. The purpose is to enable accurate detection of angular positions.

Means for Solving the Problems The present invention has the configuration shown in FIG. 1 in order to solve the above-mentioned problems. The rotation angle sensor l outputs a reference position signal at a reference position during one revolution of the internal combustion engine, and also outputs a rotation angle position signal every time the internal combustion engine rotates by a predetermined angle. The counter 2 counts the rotation angle position signal from the rotation angle sensor 1, and when the count value reaches the second set value, the count value is set as the first set value. The determining means 3 determines whether the count value of the counter 2 has changed from the first set value to the second set value before the reference position signal is generated. If it is determined by the determining means 3 that the count value of the counter has not changed from the first set value to the second set value before the reference position signal is generated, the control means 4 changes the count value of the counter to the second set value. 1, and on condition that the reference position signal is generated, the count value of the counter is set as the second set value, and before the determination means 3 generates the reference position signal, the count value of the counter becomes the first setting value. If it is determined that the set value has changed to the second set value, the count value of the counter is set as the second set value.

Embodiment FIG. 2 is a block diagram of an embodiment of the present invention, in which 21 is an internal combustion engine, 22 is a crank angle sensor, n is a throttle valve, 24 is a bypass passage that bypasses downstream and upstream of the throttle valve. 4 is an eye JL/speed control valve (isc valve), 26 is an air amount sensor that detects the intake air amount, 27 is an intake air temperature sensor that detects the temperature of the intake air,
28 is an opening sensor that detects the opening of the throttle valve 23;
4 is a pressure sensor that detects the pressure in the intake pipe, 30 is an injector, 31 is a spark plug, 32 is an 02 sensor, 33
34 is a processing section, 34 is a human power section, 35 is a converter, 36 is an output section, 37 is a memory, and 38 is a microprocessor. Incidentally, the crank angle sensor 22 receives the rotational angle position signals 01 to C12 and the top dead center signal Gl shown in FIGS. 3(A) to 3(C).
G2. Further, in this embodiment, the rotation angle position signals 01 to C12 are output every time the internal combustion engine rotates by 30° CA, and the top dead center signals Gl, G2
are output every time the internal combustion engine rotates by 720° CA, and their phases differ from each other by 360° CA. Further, FIG. 4 is a flowchart showing the processing contents of the microprocessor 38, and the operation of FIG. 2 will be explained below with reference to FIGS. 3 and 4.

The microprocessor 3 performs the processing shown in the flowchart of FIG. 5 every time the rotation angle position signals 01 to C12 are applied from the crank angle sensor 22 via the input section 34, and in step S1, the flag F1 is set to "0". Note that the flag F1 is as described below.
A counter provided in software inside the microprocessor 38 (the count value CNT is incremented by 1 each time the rotation angle position signal is applied, and when the rotation angle position signal is applied when the count value CNT is "12" is the count value CNT
is "1"), the count value CNT is the top dead center signal Gl
, G2 changes from "I2" to "1" before being applied, it becomes "1", and when the top dead center signal Gl, G2 is applied, it becomes "0". Here, the top dead center signal Gl.

The reason why the count value CNT of the counter changes from "12" to "1" before G2 is applied is when noise is superimposed on the rotational angular position signal. Therefore, in step S1, noise is superimposed on the rotational angular position signal. This means that it is determined whether or not they are superimposed.

First, the processing contents of the microprocessor 38 when the determination result in step S1 is YES, that is, when noise is superimposed on the rotation angle position signal, will be explained. If the determination result in step S1 is YES, the microprocessor 38 determines whether the top dead center signal G1 is applied or not in step S2.
), if the determination result in step S2 is NO, it is determined whether the top dead center signal G2 is applied (step S3).

If the judgment result in step S3 is NO, the microprocessor 3 increments the count value CNT of a counter provided internally by software in step S4.
), then the count value CNT of the counter is CNT≦12
It is determined whether or not the following conditions are satisfied (step 35).

If the judgment result in step S5 is NO, the microprocessor sets the flag F1 to "1" on the third day (step S6).
, then determine whether flag F2 is "0" (
Step S7). Incidentally, does the flag F2 occur between the generation of the top dead center signal Gl and the generation of the top dead center signal G2?
This indicates whether the period is from when the top dead center signal G2 is generated until when the top dead center signal G1 is generated, and the flag F2=r
IJ is the top dead center signal G after the top dead center signal G1 is generated.
The flag F2=rOJ corresponds to the period from when the top dead center signal G1 is generated until the top dead center signal G2 is generated. And step S
If the judgment result in step 7 is No, the microprocessor 38
sets the flag F2 to rOJ, then sets B=1 (step S9), then sets the count value CNT of the counter to B (1 in this case) (step 510), and moves on to the control step for this retransmission.

If the determination result in step S2 is YES, the flag F1 is set to "0" (step 5ll), and then the flag F
2 as "1" (step 512), and then step S
Perform the process in step 9. Also, if the determination result in step S3 is Y
In the case of ES, set flag F1 to "0" and step 513
), then the process of step S8 is performed. If the judgment result in step S5 is YES, B is set as the count value CNT of the counter (step 514), and then the process of step 510 is performed, and if the judgment result in step S7 is YES, step S12 is performed. It performs processing.

That is, if it is determined in step S1 that noise is superimposed on the rotation angle position signal output from the crank angle sensor 22, the count value CNT of the counter is
Regardless of what happens, the count value CNT of the counter is set to "1" when the top dead center signals Gl and G2 are applied.
Toshiki step S2. S3゜59.510), and
Each time the rotation angle position signal is added, the count value CNT of the counter is increased by +1 in step S4. 55. 510.5
14) If the rotation angle position signal is applied when the count value CNT of the counter is "12", the count value CNT
is set to "1" (Step 35. S9.
5IO).

Next, a description will be given of the processing contents of the microprocessor 38 when the determination result in step S1 is NO and no noise is superimposed on the hitting and rotation angle position signals.

If the determination result in step S1 is NO, the microprocessor 38 determines whether the count value CNT of a counter provided internally as software satisfies CNT<12 (step 515), step S15
If the result of the determination is NO, the process of step S2 is performed, and if the result of the determination is YES, the process of step S4 is performed.

That is, when it is determined in step S1 that noise is not superimposed on the rotation angle position signal output from the crank angle sensor 22, if the count value CNT of the counter is less than "12", the top dead center signal Gl, G2 is applied, the count value CNT is not set to "1" (achieved by skipping steps S2 and S3), but the count value CNT is increased by +1 in steps S4゜35, 514. 510)
, and the count value CNT is "12" or more (in this case, 1
2), the top dead center signal Gl.

When G2 is applied, the count value CNT is set to "1" (steps S2, S3, S9, 5IO).

Therefore, according to this embodiment, even when noises (c) and (d) are superimposed as shown by the dotted line in FIG. 3(A), the flag F1 is Figure 3 (
As shown in E), it is "1", and the top dead center signal G2
As shown in FIG. 3(D), the count value CNT of the counter is set to "1".
), the counter count value CN↑
There is no longer a situation where the deviation between this and the actual rotational angular position of the internal combustion engine continues semi-permanently. Also, according to this embodiment, the third
Even when noise (E) is superimposed as shown by the dotted line in Figure (C), at the time when the noise (E) occurs, the flag F1 is set to "0", the count value CNT of the counter will not become "1" due to noise (e), and therefore the top dead center signal will not change as in the conventional example shown in FIG. 5(D). Gl,
There is no possibility that the count value CNT of the counter deviates from the actual rotational angular position of the internal combustion engine due to the noise superimposed on G2. The dotted line in FIG. 3(D) indicates the count value C of the counter when noises (C) and (D) are superimposed.
This indicates NT.

As described in detail, the present invention is such that the count value of the counter reaches the first setting value (in the embodiment) before the reference position signal (top dead center signal Gl, G2 in the embodiment) is generated. It is r
12J) to the second setting value (“l” in the example)
, the counter count value is set to the second set value when the reference position signal is generated, so even if noise is superimposed on the rotation angle position signal, the counter count value and The period during which the rotational angular position of the internal combustion engine deviates from the rotational angular position can be defined as the period during which the internal combustion engine makes one rotation, and the count value of the counter changes from the first reference value to the second reference value before the reference position signal is generated. If the value does not change, the count value of the counter is the first set value,
In addition, since the count value of the counter is set as the second set value on the condition that the reference position signal is generated, the noise superimposed on the reference position signal may cause the count value to differ from the actual rotational angular position of the internal combustion engine. This has the advantage that it will not shift. Therefore, it is preferable if the present invention is applied to timing control of ignition timing, injection timing, etc. of an internal combustion engine.

[Brief explanation of drawings]

1 is a block diagram of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of the operation of FIG. 2, and FIG. 4 is a flowchart showing the processing contents of the microprocessor 38. FIG. 5 is an explanatory diagram of the operation of the conventional example. 1 is a rotation angle sensor, 2 is a counter, 3 is a judgment means, 4 is a control means, 21 is an internal combustion engine, 22 is a crank angle sensor,
24 is a bypass passage, 5 is an isc valve, 26 is an air amount sensor, 27 is an intake temperature sensor, 28 is an opening sensor, 29 is a pressure sensor, 30 is an injector, 3
1 is a spark plug, 32 is a 02 sensor, 33 is a processing unit, 3
4 is an input section, 35 is an AD converter, 36 is an output section, 37 is a memory, and 38 is a microprocessor. Patent applicant Fujitsu Ten Ltd. (1 other person) Representative patent attorney Gobe Tamamushi (1 other person) 1K 2 Figure 23: Socket/Sotol valve 30; Injector 24: Bypass passage 31; Spark plug 25: ISC valve 32: 02 sensor 27; intake temperature sensor 33: processing section 28; hearing sensor 29; pressure sensor i4 Figure

Claims (1)

[Claims] a rotation angle sensor that outputs a reference position signal at a reference position during one revolution of an internal combustion engine and outputs a rotation angular position signal every time the internal combustion engine rotates by a certain angle; and the rotation angular position signal from the rotation angle sensor. a counter that counts and sets the count value as a second set value when the count value reaches a first set value; and a counter that sets the count value to the first set value before the reference position signal is generated. determining means for determining whether the count value of the counter has changed from the first set value to the second set value before the reference position signal is generated by the determining means; If it is determined that the counter value has not changed to the set value, the count value of the counter is changed to the second set value on the condition that the counter value of the counter is the first set value and the reference position signal is generated. set value, and if the determining means determines that the counter value of the counter has changed from the first set value to the second set value before the reference position signal is generated,
A rotational angular position detection device for an internal combustion engine, comprising: control means for setting the count value of the counter to a second set value when the reference position signal is generated.