JP5556760B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device that performs cylinder discrimination based on a crank angle signal and a cam angle signal, and sequentially updates an engine rotation position in one combustion cycle based on the crank angle signal.

  Conventionally, a crank angle signal having a reference position signal representing a predetermined angular position in a signal train generated at predetermined angular intervals as the crankshaft of the engine rotates, and a reference position signal corresponding to the rotation of the camshaft of the engine Cylinder discrimination is performed based on the cam angle signal that is generated at the selected position and indicates the rotational position of the camshaft, and the engine rotation position in one combustion cycle including the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke is determined based on the crank angle signal. There is known an engine control device that counts and updates sequentially. The engine control device injects fuel based on the engine rotational position and burns the fuel in an appropriate cylinder.

  As such an engine control device, after the completion of cylinder discrimination, for example, in order to correct the deviation of the count value of the engine rotation position due to noise or the like, the engine rotation position is set to a value corresponding to the cam angle signal every time the reference position signal is detected. Some set the count value. However, if the cam angle signal is erroneously detected due to disconnection or sensor abnormality, the engine rotational position may be set based on the erroneous cam angle signal.

  Therefore, in the engine control device disclosed in Patent Document 1, the engine rotation position is set depending on whether the cam angle signal is at a low level or a high level with respect to a reference position signal generated at one position during one rotation of the crankshaft. If the previous and current cam angle signal levels are the same, it is determined that the cam angle signal is abnormal, and the engine rotation position is not set.

JP 2001-90600 A

  However, in Patent Document 1, since a low-level or high-level cam angle signal is alternately output for each reference position signal, the time during which the same level cam angle signal is generated is long. As a result, for example, if the reference position signal is generated at a position different from the normal angular position, there is a high possibility that the reference position signal is generated before the normal angular position when the cam angle signal is at the same high level.

  In this case, the cam angle signal corresponding to the reference position signal generated at the abnormal position is high level, and the cam angle signal corresponding to the previous reference position signal generated at the normal position is low level. It is different and normal. As a result, there is a problem that the engine rotational position is likely to be erroneously set at the abnormal position based on the high level of the cam angle signal corresponding to the reference position signal generated at the abnormal position.

  Further, as in Patent Document 1, the cam angle signal abnormality can be detected by comparing the previous and current cam angle signals corresponding to the reference position signal. However, for example, in the case of having different reference position signals at different angular positions in the crank angle signal, in the method of comparing the previous and current cam angle signals, even if a different reference position signal is generated at a predetermined angular position, An error in the reference position signal cannot be detected.

  The present invention has been made to solve the above-described problems, and provides an engine control device that can reduce the possibility of erroneous setting of the engine rotation position and can detect abnormality of the reference position signal and the cam angle signal. Objective.

According to the first to fifth aspects of the present invention, a crank angle signal having a reference position signal representing a predetermined angular position in a signal train generated at predetermined angular intervals as the crankshaft of the engine rotates, and an engine cam Cylinder discrimination is performed based on a cam angle signal in which a combination of the number of signals generated at a position corresponding to the reference position signal with the rotation of the shaft and a reference position signal is different for each reference position signal in one combustion cycle. In the engine control apparatus that sequentially updates the engine rotation position in one combustion cycle based on the signal, the pattern determination means is a combination in which the previous and current generation patterns of the combination of the reference position signal and the cam angle signal are continued a predetermined number of times. It is determined whether the combination until this time is normal or not, and the rotational position setting means determines that the determination result by the pattern determination means is normal. , To set the engine rotational position in one combustion cycle based on this combination, if the judgment result is not normal, not set engine rotational position.

  One combustion cycle includes an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, and corresponds to an angle of two rotations of the crankshaft and one rotation of the camshaft. The engine rotational position represents the rotational position of the engine at the rotational angle of one combustion cycle, and the stroke position of each cylinder is determined based on the engine rotational position.

Thus, in the invention according to claims 1 to 5 , in the configuration in which the combination of the reference position signal and the number of signals of the cam angle signal is different for each reference position signal in one combustion cycle, the reference position signal and the cam angle signal Because it is determined whether the occurrence pattern of the previous and current combinations of the number of signals is normal, even if a reference position signal is generated at an abnormal position different from the normal generation position, this abnormal position can be handled. No cam angle signal is generated. As a result, the number of cam angle signals corresponding to the reference position signal generated at the abnormal position is likely to be a limited number such as 0, and the possibility that the number of signals is 1 or more is low.

  As a result, the occurrence pattern of the combination of the reference position signal generated at the abnormal position and the number of cam angle signal signals corresponding to the abnormal position and the combination generated at the previous normal position is likely to be abnormal. Therefore, even if the reference position signal is generated at a position different from the normal generation position, the possibility that the engine rotational position is erroneously set is low.

  Further, since it is determined whether or not the generation pattern of the previous and current combinations of the reference position signal and the cam angle signal is normal, there are a plurality of reference position signals, and different reference position signals are generated at different angular positions. In this case, when the generation pattern of the combination of the reference position signal and the cam angle signal is different from the normal pattern, it can be determined that an abnormality has occurred in either the reference position signal or the cam angle signal.

  If the occurrence pattern is abnormal, the engine rotational position is not set, so that it is possible to prevent the engine rotational position from being erroneously set when an abnormality occurs in either the reference position signal or the cam angle signal.

According to the first aspect of the present invention, when the pattern determining means determines that the generated pattern is abnormal after the cylinder determination is completed at the time of starting the engine and before the determination result by the pattern determining means becomes normal. Then, the cylinder discrimination is incomplete and the cylinder discrimination is restarted.

  According to this configuration, at the time of starting the engine, the cylinder position is discriminated because, for example, the combination of the reference position signal and the cam angle signal coincides with the normal combination even though the reference position signal or the cam angle signal is abnormal. Even if it is completed, if the occurrence pattern is abnormal, the cylinder discrimination is made incomplete and the cylinder discrimination is resumed.

  As a result, the cylinder discrimination can be resumed even if the cylinder discrimination is mistakenly completed when the engine is started. Therefore, it is possible to prevent the fuel control from being continued based on the engine rotation position set based on the erroneous cylinder discrimination result.

  Here, for example, when the cam angle signal has a fixed value due to disconnection or sensor abnormality, and the combination of the reference position signal and the fixed value cam angle signal coincides with the normal combination when the engine is started, the cylinder discrimination is completed. Even if the cylinder discrimination is not completed when the occurrence pattern is abnormal and the cylinder discrimination is restarted, the combination of the reference position signal and the fixed cam angle signal matches the normal combination. Will be completed.

Therefore, according to the second aspect of the invention, the cylinder discrimination means restarts the cylinder discrimination when the determination result by the pattern determination means becomes normal after the cylinder discrimination is incomplete.
As a result, when the cylinder discrimination is incomplete and the fuel injection is stopped, the cylinder discrimination is resumed after the judgment result by the pattern judgment means becomes normal, so that the possibility of erroneous cylinder discrimination is reduced. This improves the accuracy of cylinder discrimination.

According to the third aspect of the present invention, the rotational position setting means is a combination of the reference position signal and the cam angle signal for each time until the determination result by the pattern determination means becomes normal after the cylinder determination is completed when the engine is started. The engine rotation position is set based on

According to this configuration, if the combination of the reference position signal and the cam angle signal at each time is normal, the engine can be started quickly by burning the fuel in an appropriate cylinder.
Here, when the engine rotation position is set based on the combination of the reference position signal and the cam angle signal each time, if the fuel burns in an appropriate cylinder based on the engine rotation position set based on the appropriate combination The engine speed quickly rises above a predetermined speed.

Therefore, according to the fourth aspect of the present invention, the rotational position setting means includes the reference position signal and the cam angle signal for each time from the completion of cylinder discrimination at the start of the engine until the rotational speed of the engine reaches a predetermined rotational speed or more. The engine rotation position is set based on the combination.

According to this configuration, if the combination of the reference position signal and the cam angle signal at each time is normal, the engine can be started quickly by burning the fuel in an appropriate cylinder.
According to the fifth aspect of the present invention, the pattern determining means determines whether or not the generation pattern of the reference position signal and the cam angle signal is normal a plurality of times.

  In this way, since it is determined whether or not the generation pattern of the reference position signal and the cam angle signal is normal multiple times in succession, the generation pattern of the previous and current combinations of the reference position signal and the cam angle signal is determined. The possibility that the engine rotational position is erroneously set can be reduced as compared with the case where it is determined whether or not the engine is normal only once.

  The functions of the plurality of means provided in the present invention are realized by hardware resources whose functions are specified by the configuration itself, hardware resources whose functions are specified by a program, or a combination thereof. The functions of the plurality of means are not limited to those realized by hardware resources that are physically independent of each other.

The block diagram which shows the engine control apparatus by this embodiment. (A) is a schematic diagram showing a configuration for generating a crank angle signal, and (B) is a schematic diagram showing a configuration for generating a cam angle signal. (A) is a time chart showing the relationship between the reference position signal, the cam angle signal, and the engine rotation position when the cam angle signal is abnormal, and (B) is the reference position signal when it is abnormal. 4 is a time chart showing the relationship among a reference position signal, a cam angle signal, and an engine rotation position when the reference position signal is abnormal. The flowchart which shows the rotational position setting process 1. FIG. The flowchart which shows the cylinder discrimination | determination process 1. FIG. 7 is a flowchart showing a rotational position setting process 2; The flowchart which shows the cylinder discrimination | determination process 2. FIG. The time chart which shows the relationship between the reference position signal at the time of cam angle signal abnormality by disconnection, a cam angle signal, and an engine rotation position. 7 is a flowchart showing a rotational position setting process 3. 7 is a flowchart showing a rotational position setting process 4.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an electronic control unit (ECU) 10 of this embodiment mounted on a vehicle.
The ECU 10 is, for example, an engine ECU that performs injection control of an injector for a gasoline engine and ignition control of a spark plug. From the CPU 12, ROM 14, RAM 16, SRAM (standby RAM) 28, EEPROM 20, input circuit 30, output circuit 32, and the like. It is configured.

  The ECU 10 causes the CPU 12 to execute a control program stored in the ROM 14, thereby inputting various signals such as an accelerator opening, a throttle opening, a vehicle speed, a crank angle, a cam angle, and an ignition switch detected by various sensors to the input circuit 30. Enter through. Based on the detection signals of these sensors, control signals such as injector injection control and ignition plug ignition control (not shown) are output via the output circuit 32.

  Unlike the RAM 16, which is used for work by the control program of the ECU 10 and when the ignition switch is turned off, the power supply is cut off and the stored data is lost. Regardless of whether the ignition switch is on or off, the SRAM 18 receives power from the battery. Supplied. Therefore, the SRAM 18 is a storage unit that stores stored data unless power supply is interrupted due to battery replacement or the like.

The EEPROM 20 is a rewritable nonvolatile storage unit. Even if the power supply from the battery is cut off, the data stored in the EEPROM 20 is preserved.
The ECU 10 stores data that needs to be stored in the SRAM 18 or the EEPROM 20 even if the ignition switch is turned off to stop the operation of the vehicle.

  The crank angle sensor 40 shown in FIG. 2 is provided on the outer periphery of the crank rotor 50 fixed to the crankshaft so as to face the crank rotor 50. Teeth are formed on the outer periphery of the crank rotor 50 at a predetermined angle (for example, 10 °) interval.

  The interval between teeth formed on the outer periphery of the crank rotor 50 is not limited to 10 °, and may be smaller or larger than 10 °. The crank angle sensor 40 outputs a crank angle signal that is a pulsed signal sequence every time the crankshaft rotates 10 ° (every 10 ° CA).

  In the middle of the tooth row of the crank rotor 50, two missing teeth 52 are continuously missing from one tooth, and two missing teeth 52 are missing at one place. A single chip missing tooth portion 54 is formed on the opposite side of 180 °. The crank angle signal when the crank angle sensor 40 detects the continuously missing missing tooth portion 52 and the single missing missing tooth portion 54 is a reference position signal when performing cylinder discrimination and setting the engine rotation position in one combustion cycle. Become.

  The ECU 10 detects the engine rotational speed by detecting the angular position of the crankshaft during one rotation based on the crank angle signal and calculating the number of pulses of the crank angle signal per unit time.

  The cam angle sensor 60 is provided on the outer periphery of the cam rotor 70 fixed to the cam shaft so as to face the cam rotor 70. Since the camshaft rotates at a ratio of 1/2 with respect to the crankshaft, the camshaft rotates once while the crankshaft rotates twice (720 ° CA). On the outer periphery of the cam rotor 70, two teeth 72 are provided at two positions, and one tooth 74 is provided at two positions at a position corresponding to a crank angle of 180 ° CA, that is, a position 90 ° apart in the rotation direction of the cam shaft. They are formed in this order.

  The two teeth 72 are formed, for example, corresponding to the compression top dead center of the # 1 cylinder and the # 3 cylinder, respectively, and the one tooth 74 is, for example, the compression top dead center of the # 2 cylinder and # 4 cylinder, respectively. It is formed corresponding to a point. The cam angle sensor 60 outputs a pulsed cam angle signal when it reaches a position facing the teeth 72 and 74 of the cam rotor. The number of cam angle signals is two or one according to the number of teeth 72 and 74.

As shown in FIG. 3, the crank rotor 50 and the cam rotor 70 are respectively assembled to the crankshaft and the camshaft so that the missing tooth portions 52 and 54 and the teeth 72 and 74 correspond to each other.
(Combination of reference position signal and cam angle signal, and generation pattern of combination)
As shown in FIG. 3, the reference position signal indicating the positions of the continuous missing tooth portion 52 and the single missing tooth portion 54 of the crank angle signal, and the positions of the two teeth 72 and one tooth 74 are shown. The combination of the number of cam angle signals generated in response to the reference position signal is as follows: 720 ° CA, which is the angle range of one combustion cycle, continuous missing and 2 teeth, single missing and 2 teeth, continuous missing and 1 tooth, There are four types of single chip and one tooth, which are different for each reference position signal. The combinations of the reference position signal and the signal number of the cam angle signal are repeated in the order of continuous missing and 2 teeth, single missing and 2 teeth, continuous missing and 1 tooth, single missing and 1 tooth.

  Therefore, if the crank angle sensor 40 detects the missing teeth 52 and 54 normally and the cam angle sensor 60 detects the teeth 72 and 74 normally, the reference position signal detected every 180 ° CA in one combustion cycle. And the cam angle signal should be different from each other. Then, a combination expected to be detected this time can be predicted from the combination detected last time.

  For example, it can be expected that a signal of a combination of a single chip and one tooth is detected next to a combination of a continuous chip and one tooth. Therefore, when it is expected that a signal of a single chip and one tooth combination will be detected next to a combination of a single chip and a single tooth as in the cam angle signal shown in FIG. Due to chipping and noise, a signal with a combination of two teeth is detected. As shown in FIG. 3B, a signal with a combination of a single chipping and two teeth is detected next to a combination of continuous chipping and two teeth. When a signal of a combination of missing teeth and two teeth is detected due to missing of the crank angle signal when it is expected, the previous and current combinations of the reference position signal and cam angle signal will be Since the occurrence pattern becomes abnormal, it can be determined that either the reference position signal or the cam angle signal is abnormal.

  In addition, the configuration of the missing teeth of the crank rotor is the same as in FIG. 2A, but the configuration of the teeth of the cam rotor is not the two teeth, two teeth, one tooth, and one tooth shown in FIG. 1 tooth, 1 tooth, 0 tooth, 0 tooth may be sufficient. Also in this case, there are four combinations of the reference position signal and the cam angle signal in one combustion cycle, and the combinations differ for each reference position signal.

  In this cam rotor configuration, the combination of the reference position signal and the cam angle signal is repeated in the order of continuous missing and 1 tooth, single missing and 1 tooth, continuous missing and 0 tooth, single missing and 0 tooth. Therefore, the combination expected to be detected this time can be predicted from the combination of the reference position signal and the cam angle signal detected last time. For example, it can be expected that a signal of a combination of a single chip and one tooth is detected next to a combination of a continuous chip and one tooth.

  Therefore, as shown in FIG. 4, when it is expected that a signal of a single chip and one tooth combination will be detected next to a combination of a single chip and a single tooth, the signal of the crank angle signal is lost. If a single missing reference position signal is generated at a position different from the normal position and a combination of single missing and zero teeth is detected, the generated pattern is abnormal, so either the reference position signal or the cam angle signal Can be determined to be abnormal.

  In addition to continuous missing and single missing as the reference position signal, for example, if three consecutive missing teeth are detected, it can be determined that the reference position signal is abnormal. In the example of FIG. In addition to the teeth, if the number of teeth is zero or three or more, or two or more teeth are detected as the cam angle signal in the example of FIG.

(Engine rotation position)
The ECU 10 divides the crank angle signal detected every 10 ° CA, and executes a rotational position update process in which a rotational position counter that counts the engine rotational position is incremented by 1 every 30 ° CA in order from 0. In the rotational position update process, when the rotational position counter value is 24, the total angle is 720 ° CA, so the rotational position counter value is returned to zero.

The ECU 10 determines the engine rotational position in one combustion cycle based on the counter value of the rotational position counter, thereby identifying the cylinder that injects fuel and ignites.
In addition, if the combination of the reference position signal and the cam angle signal is normal when the engine is started, the ECU 10 sets the value of the rotational position counter based on this combination and completes the cylinder discrimination.

(Rotation position setting process 1, cylinder discrimination process 1)
Next, the rotational position setting process 1 (FIG. 5) and the cylinder discrimination process 1 (FIG. 6) executed by the ECU 10 when the CPU 12 executes a control program stored in the ROM 14 or the like will be described. The flowchart of FIG. 5 is executed when the reference position signal of the crank angle signal is detected every 180 ° CA. In FIG. 5 and subsequent flowcharts, “S” represents a step.

  In S400 of FIG. 5, the ECU 10 determines whether or not the cylinder determination is completed. When the cylinder discrimination has not been completed (S400: No), the ECU 10 executes a cylinder discrimination process 1 in S402.

  FIG. 6 shows the cylinder discrimination process 1 executed in S402 of FIG. In S420 of FIG. 6, the ECU 10 determines that the combination of the reference position signal and the cam angle signal is, for example, a single chip and two teeth, a continuous chip and one tooth, a single chip and one tooth, or a continuous chip shown in the time chart of FIG. And whether it is a normal predetermined combination of any one of the two teeth.

  If the combination of the reference position signal and the cam angle signal is not a predetermined combination (S420: No), the ECU 10 does not complete the cylinder discrimination and ends this process. Therefore, the cylinder discrimination is not completed until the combination of the reference position signal and the cam angle signal becomes a predetermined combination.

  If the combination of the reference position signal and the cam angle signal is a predetermined combination (S420: Yes), the rotational position counter is set to 0, 6, 12, 18 based on the combination of the current reference position signal and the cam angle signal. It is set to either (S422), the cylinder discrimination state is set to “complete” (S424), and the normal counter is set to 1 (S426). When the cylinder discrimination process of FIG. 6 ends, the ECU 10 ends the process of FIG.

  In the normal counter, the combination of the current reference position signal and the cam angle signal is normal in the rotational position setting process 1 of FIG. 5, and the previous and current generation patterns of the combination of the reference position signal and the cam angle signal are as follows. Incremented (+1) when normal.

  That is, when the normal counter is 1, the current combination is normal, but the previous and current occurrence patterns are not yet normal. When the normal counter is 2, the occurrence pattern of the previous and current combinations is normal once. When the normal counter is 3, the occurrence pattern of the previous and current combinations is normal twice. The value of the normal counter is guarded at the upper limit value or a predetermined value so as not to return to the initial value after being counted up to the upper limit value, and the increment is stopped.

  When the cylinder determination is completed in S400 of FIG. 5 (S400: Yes), the ECU 10 determines whether or not the reference position signal and the cam angle signal are a normal predetermined combination (S404).

  When the reference position signal and the cam angle signal are not a predetermined combination (S404: No), the ECU 10 determines that either the current reference position signal or the cam angle signal is abnormal and sets the normal counter to 0. (S406), and the process proceeds to S414.

  If the reference position signal and the cam angle signal are a predetermined combination (S404: Yes), the ECU 10 calculates the expected combination from the previous combination of the reference position signal and the cam angle signal (S408). For example, if the last time is a combination of continuous missing and one tooth, the expected combination is calculated as a combination of single missing and one tooth.

  When the previous combination or the occurrence pattern is abnormal, the ECU 10 sets the combination detected this time as the combination expected this time from the previous combination in S408. This process is the same in other flowcharts other than FIG. If the normal counter is 0, it can be determined that the previous combination or occurrence pattern was abnormal.

  If the combination detected this time matches the combination expected this time from the previous combination (S410: Yes), the ECU 10 increments (+1) the normal counter (S412), and shifts the processing to S414.

  When the combination detected this time does not match the combination expected this time from the previous combination, that is, when the generation pattern between the previous time and the current time of the combination of the reference position signal and the cam angle signal is abnormal (S410: No), the ECU 10 Determines that either the current reference position signal or the cam angle signal is abnormal, sets the normal counter to 0 (S406), and shifts the process to S414.

  If the normal counter is greater than or equal to the predetermined number in S414 (S414: Yes), the ECU 10 sets the value of the rotational position counter based on the combination of the reference position signal and the cam angle signal detected this time (S416). For example, in the time chart shown in FIG. 3, when a combination of single missing and 2 teeth, continuous missing and 1 tooth, single missing and 1 tooth, continuous missing and 2 teeth is detected, the rotational position counter is set to 0, 6, 12, Set to 18. This is because when the count value of the rotational position counter deviates for some reason, it is reset to a normal count value.

  In the rotational position setting process 1 of FIG. 5, the predetermined number of times is set to 2 in S414. As a result, the combination of the previous position and the current position of the reference position signal and the cam angle signal is a predetermined combination after completion of the cylinder determination, including when the cylinder determination is completed. If the generated pattern of the generated combination is normal, that is, if the generated pattern is normal once, in S416, the ECU 10 rotates the value of the rotational position counter based on the combination of the current reference position signal and the cam angle signal. Set regardless of location update processing.

  The value of the predetermined number need not be limited to 2. If the predetermined number of times is set to 3 or more, whether or not the previous and current generation patterns of the combination of the reference position signal and the cam angle signal are normal until the current combination for the combination of three or more consecutive times, that is, occurrence It is determined whether or not the pattern is normal continuously several times.

  If the normal counter is less than the predetermined number of times (S414: No), the ECU 10 ends this process without setting the value of the rotational position counter. If the value of the rotational position counter is not set in the process of FIG. 5, the rotational position counter value is continuously updated by the rotational position update process.

  Here, as shown in FIG. 3A, if the cam angle signal is erroneously detected as two teeth due to noise when the reference position signal is single missing, a combination of the reference position signal and the cam angle signal. Because it is a single chip and two teeth, it is a predetermined combination, so it does not determine the previous and current generation patterns of the combination of the reference position signal and the cam angle signal, and only the combination of the current reference position signal and the cam angle signal. , The rotational position counter is erroneously set to 0 as indicated by the dotted line 200 based on the combination of single teeth and two teeth due to noise.

  However, since the current combination expected from the combination of continuous missing and one tooth before erroneous detection is a single missing and one tooth, the generation pattern of the previous and current combinations of the reference position signal and the cam angle signal is shown. By the determination, the determination in S410 is “No”, and the normal counter is set to zero.

  As a result, even if one tooth of the cam angle signal is erroneously detected as two teeth due to the occurrence of noise, the value of the rotational position counter is not set to 0 corresponding to single missing and two teeth, and is updated by the rotational position updating process. Continues normally.

  Further, as shown by a dotted line in FIG. 3B, when a single missing reference position signal is detected due to missing of the crank angle signal, a combination of the reference position signal and the cam angle signal is detected. Is a missing combination and two teeth, and because it is a predetermined combination, only the combination of the current reference position signal and cam angle signal is determined without determining the previous and current generation patterns of the combination of the reference position signal and cam angle signal. In the case of determination, the rotational position counter is erroneously set to 18 as shown by the dotted line 210 based on the combination of the consecutive lack due to signal loss and the two teeth.

  However, since the current combination expected from the combination of continuous missing and two teeth before erroneous detection is a single missing and two teeth, the generation pattern of the previous and present reference position signal and cam angle signal is determined. As a result, the determination in S410 is “No”, and the normal counter is set to zero.

  As a result, even if a single missing reference position signal is erroneously detected as missing due to missing signals, the value of the rotational position counter is not set to 18 corresponding to consecutive missing and 2 teeth, and updating by the rotational position updating process is normal. To be continued.

  In the case of the time chart shown in FIG. 4, a single missing reference position signal is generated at a position different from the normal position due to missing of the crank angle signal, and a signal of a combination of single missing and zero teeth is detected. The combination of the reference position signal and the cam angle signal is single missing and 0 teeth, and is a predetermined combination. Therefore, the generation pattern between the previous time and the current time of the combination of the reference position signal and the cam angle signal is not determined. When only the combination of the reference position signal and the cam angle signal is determined, the rotational position at an angular position different from the predetermined position, as shown by a dotted line 220, based on the combination of single missing due to signal loss and zero teeth. The counter is set to 12 incorrectly.

  However, since the current combination expected from the combination of continuous missing and one tooth before erroneous detection is a single missing and one tooth, the generation pattern of the previous and current combinations of the reference position signal and the cam angle signal is By the determination, the determination in S410 is “No”, and the normal counter is set to 0.

  Thus, even if a single missing reference position signal is erroneously detected at a position different from the normal position due to missing of the crank angle signal, the value of the rotational position counter is set to 12 corresponding to the single missing and zero teeth. The update by the rotational position update process is normally continued.

  In this way, since it is determined whether or not the generation pattern of the previous and current combinations of the reference position signal and the cam angle signal is normal, the combination of the reference position signal and the cam angle signal is normal. When there is an abnormality in either the reference position signal or the cam angle signal, the abnormality can be detected.

  Then, when the generation pattern between the previous time and the current time of the combination of the reference position signal and the cam angle signal is abnormal, the rotation position counter value is not set, so that the rotation position counter is continuously updated by the rotation position update process. Therefore, fuel can be burned in an appropriate cylinder.

  In the rotational position setting process 1 of FIG. 5, the processes of S404 to S414 correspond to the function executed by the pattern determining unit of the present invention, and the process of S416 corresponds to the function executed by the rotational position setting unit of the present invention.

The ECU 10 corresponds to the engine control device of the present invention, and realizes functions executed by the pattern determination unit and the rotational position setting unit of the present invention.
(Rotation position setting process 2, cylinder discrimination process 2)
FIG. 7 shows a flowchart of another rotational position setting process 2, and FIG. 8 shows a flowchart of another cylinder discrimination process 2. The time chart shown in FIG. 9 is an example in which the crank angle signal is not lost in the time chart of FIG. 4, but the output level of the cam angle signal is fixed to low due to disconnection or abnormality of the cam angle sensor 60.

As shown by the dotted line in FIG. 9, even if the cam angle signal is detected as 0 teeth by disconnection or the like at the position where the cam angle signal is originally detected by 1 tooth, the combination of continuous missing and 0 missing or single missing and 0 tooth is normal. For example, if a combination of continuous missing and zero teeth is detected by erroneous detection when the engine is started, the cylinder discrimination is erroneously determined to be complete. The next single missing and zero tooth combination is also a predetermined combination. Since the generation pattern of chipping and zero teeth and single chipping and zero teeth is normal, fuel is injected. However, when the combination of the next continuous chip and zero teeth is detected, the generation pattern of the previous single chip and zero teeth erroneously detected due to disconnection and the current continuous chip and zero teeth is abnormal.

  As described above, when the abnormality of the occurrence pattern is detected after the cylinder discrimination is once completed at the time of starting the engine, in the flowcharts of FIGS. 7 and 8, the occurrence patterns of the previous and present combinations of the reference position signal and the cam angle signal are shown. However, the cylinder discrimination is not resumed until it is determined that the combination of the reference position signal and the cam angle signal that has continued for a predetermined number of times is normal until the current combination. Hereinafter, “the occurrence pattern of the previous and present combinations of the reference position signal and the cam angle signal is normal until the present combination with respect to the combination of the reference position signal and the cam angle signal that has continued for a predetermined number of times” is simply “continuous. It is also said that the occurrence pattern is normal for the combination.

  Thus, when an abnormality in the generation pattern is detected after the cylinder discrimination is completed at the time of starting the engine, erroneous fuel injection is prevented until “the generation pattern is normal for successive combinations”.

  Hereinafter, the specific processing of FIGS. 7 and 8 will be described. In FIG. 7, the processes of S440 and S444 to S452 are substantially the same as the processes of S400 and S404 to S412 of FIG.

  In S440 of FIG. 7, the ECU 10 determines whether or not cylinder discrimination is complete. If the cylinder discrimination is not completed (S440: No), the ECU 10 executes the cylinder discrimination process 2 of FIG. 8 in S442.

  In S470 of the cylinder discrimination process 2 in FIG. 8, the ECU 10 determines whether or not the cylinder discrimination stop flag is on. The initial value of the cylinder discrimination stop flag is set to off. Then, in the rotational position setting process 2 of FIG. 7, after the cylinder discrimination is completed, before the “occurrence pattern is normal for consecutive combinations”, the combination of the reference position signal and the cam angle signal, or the reference position signal and the cam angle. If the generation pattern of the previous and current signals is abnormal, the cylinder discrimination stop flag is set to on.

  When the cylinder discrimination stop flag is off (S470: No), the ECU 10 determines whether or not the combination of the reference position signal and the cam angle signal is a predetermined combination (S472). If it is not a predetermined combination (S472: No), the ECU 10 ends the cylinder discrimination process 2. When the cylinder discrimination process 2 in FIG. 8 ends, the ECU 10 ends the process in FIG.

  If it is a predetermined combination (S472: Yes), the ECU 10 proceeds to S486 to set the rotational position counter to any of 0, 6, 12, and 18 (S486), and the cylinder discrimination state is “completed”. (S488), the cylinder discrimination stop flag is set to OFF (S490), and the normal counter is set to 1 (S492).

  In the determination of S472, as shown by the dotted line in FIG. 9, even if the cam angle signal is detected as 0 teeth due to a disconnection or the like at a position where it is originally detected by 1 tooth, continuous missing and 0 teeth, single missing and 0 teeth Since each combination is a normal predetermined combination, the combination of the reference position signal and the cam angle signal is determined to be a predetermined combination even if a combination of missing teeth and zero teeth is detected due to erroneous detection when the engine is started. .

  As a result, if there is no disconnection or the like, a combination of continuous missing and one tooth is detected, so that normally 18 is set in the rotational position counter as indicated by the solid line, but as indicated by the dotted line 230. Incorrect 6 is set in the rotational position counter. Since it is erroneously determined that the cylinder discrimination has been completed, fuel is erroneously injected.

  Then, when the cylinder position determination is completed when the reference position signal is continuously missing and the cam angle signal is detected as 0 teeth due to disconnection or the like, in the rotational position setting process 2 in FIG. The detected zero teeth are a predetermined combination (S444: Yes), and the occurrence pattern of the previous consecutive missing and zero detected teeth and the current single missing and erroneously detected zero teeth is erroneously determined as normal. Therefore (S450: Yes), the cylinder discrimination completion state remains “completed”.

  However, the combination of the continuous missing and 0 teeth detected after the single missing and erroneously detected 0 teeth is normal (S444: Yes), but the previous single missing and the erroneously detected 0 teeth, the current consecutive missing and Since the generation pattern of the 0 teeth is abnormal (S450: No), the normal counter is set to 0 (S446).

  In the rotational position setting process 2 of FIG. 7, the predetermined number of times is set to 3 in S454. Therefore, even if the occurrence pattern of the consecutive missing and erroneously detected 0 teeth when the cylinder determination is erroneously determined and the subsequent single missing and erroneously detected 0 teeth is erroneously determined to be normal and the normal counter becomes 2. Since the determination in S454 is “No”, the rotation position state is not set to be fixed in S458. Since the initial value of the rotational position state is set to “indeterminate”, it remains “indeterminate” until S458 is executed.

  Therefore, the occurrence pattern of the previous single missing and falsely detected 0 teeth and the current consecutive missing and 0 teeth is abnormal (S450: No), the normal counter is set to 0 (S446), and the normal counter is predetermined. When the number is less than the number of times (S454: No), the engine rotational position is unconfirmed (S460: No), and the normal counter is 0 (S462: Yes), so the cylinder discrimination state is set to “incomplete” (S464). ), The cylinder discrimination stop flag is set to “ON” (S466).

Thereby, since it is determined that cylinder discrimination is not completed in S440 of the next rotational position setting process 2 (S440: No), the cylinder discrimination process 2 of FIG. 8 is executed.
When the cylinder discrimination is not completed and the cylinder discrimination stop flag is set to ON, as shown in the time chart of FIG. 9, if the cam angle signal is fixed at a low level due to disconnection, the occurrence shown in FIG. Even if S474 to S482 in FIG. 8 are executed after determining the abnormality of the pattern, the normal counter does not become two or more of the predetermined number in S484 in FIG.

  Therefore, if the predetermined number of S484 is set to 2, cylinder discrimination remains incomplete. As a result, the fuel is not erroneously injected after the abnormality of the occurrence pattern of FIG. 9 is determined. Note that the predetermined number of times of S484 in FIG. 8 is not 2, but may be 3 as in S454 in FIG.

In the rotational position setting process 2 in FIG. 7 and the cylinder discrimination process 2 in FIG. 8, the processes in S444 to S454 in FIG. 7 and S474 to S484 in FIG. 8 correspond to the functions executed by the pattern determining means of the present invention. The processing of S456 corresponds to the function executed by the rotational position setting means of the present invention, and the processing of S464 and S466 of FIG. 7 and S470, S472, and S486 to S492 of FIG. It corresponds to.

(Rotation position setting process 3)
FIG. 10 shows a flowchart of another rotational position setting process 3. The cylinder discrimination process 1 executed in S502 of FIG. 10 is the same as the cylinder discrimination process 1 of FIG.

In FIG. 10, the processes of S500 to S512 are substantially the same as the processes of S400 to S412 of FIG.
If the normal counter is greater than or equal to the predetermined number in S514 of FIG. 10 (S514: Yes), that is, if the “occurrence pattern is normal for consecutive combinations”, the ECU 10 sets the rotational position state to “determined” (S516). The engine rotation position is set based on the combination of the current reference position signal and the cam angle signal (S518). However, if the determination in S504 is “No”, S518 may be executed. Therefore, if the combination of the current reference position signal and the cam angle signal is not a predetermined combination, the engine rotation position is not set.

  If the normal counter is less than the predetermined number of times (S514: No), the ECU 10 determines whether or not the engine rotational position is determined (S520). When the engine rotation position is fixed (S520: Yes), the ECU 10 ends this process. Thus, the ECU 10 continues to update the rotational position counter by the rotational position update process.

  When the engine rotational position is not fixed (S520: No), the ECU 10 sets the engine rotational position based on the combination of the current reference position signal and the cam angle signal (S518). That is, when the engine is started, the ECU 10 sets the engine rotation position based on the combination of the current reference position signal and the cam angle signal until “the occurrence pattern is normal for successive combinations”.

  Thus, if the combination of the current reference position signal and the cam angle signal is normal, the fuel can be injected and combusted in an appropriate cylinder until the “occurrence pattern is normal for successive combinations” when the engine is started. As a result, the engine can be started quickly.

  In the rotational position setting process 3 of FIG. 10, the processes of S500 to S514 correspond to the function executed by the pattern determining unit of the present invention, and the process of S518 corresponds to the function executed by the rotational position setting unit of the present invention.

(Rotation position setting process 4)
FIG. 11 shows a flowchart of another rotational position setting process 4. The cylinder discrimination process 1 executed in S532 of FIG. 11 is the same as the cylinder discrimination process 1 of FIG.

In FIG. 11, the processes of S530 to S542, S546, and S548 are substantially the same as the processes of S400 to S416 of FIG.
In S544 of FIG. 11, the ECU 10 determines whether or not the engine speed is equal to or higher than a predetermined speed. The predetermined rotational speed is set to a value lower than the idle rotational speed.

  If the engine speed is less than the predetermined speed (S544: No), the ECU 10 does not determine whether or not the normal counter is greater than or equal to the predetermined number in S546, that is, the combination of the reference position signal and the cam angle signal. Regardless of whether the previous and current occurrence patterns are normal, the engine rotational position is set based on the combination of the current reference position signal and the cam angle signal (S548). However, if the determination in S534 is “No”, S548 may be executed. Therefore, if the combination of the current reference position signal and the cam angle signal is not a predetermined combination, the engine rotation position is not set.

  Thus, if the combination of the current reference position signal and the cam angle signal is normal, the fuel can be injected and combusted in an appropriate cylinder before the engine speed rises to a predetermined speed or higher when the engine is started. As a result, the engine can be started quickly.

  If the engine speed is equal to or higher than the predetermined speed (S544: Yes), the ECU 10 determines that the fuel is combusted in an appropriate cylinder when the engine is started and the engine speed has increased to the predetermined speed or higher, and the normal counter is predetermined. It is determined whether or not the number is the number of times (S546).

If the normal counter is greater than or equal to the predetermined number of times (S546: Yes), the engine rotational position is set based on the combination of the current reference position signal and the cam angle signal.
If the normal counter is less than the predetermined number of times (S546: No), the ECU 10 ends this process without setting the engine rotation position.

  In the rotational position setting process 4 of FIG. 11, the processes of S530 to S542 and S546 correspond to the functions executed by the pattern determining means of the present invention, and the processes of S544 and S548 are functions executed by the rotational position setting means of the present invention. It corresponds to.

[Other Embodiments]
What is necessary is just to set suitably the predetermined frequency compared with a normal counter in the rotation position setting process and cylinder discrimination | determination process of the said embodiment according to the structure of a reference position signal and a cam angle signal.

  In the present embodiment, the combination of the reference position signal and the cam angle signal is set in the cylinder discrimination process 2 in FIG. 8 after the cylinder discrimination state is set to “incomplete” in the rotational position setting process 2 shown in FIG. The cylinder discrimination is not resumed until it is determined that the occurrence pattern of the previous time and the current time is normal until the current combination of the reference position signal and the cam angle signal that are consecutive a predetermined number of times.

  On the other hand, in the rotational position setting process 2 shown in FIG. 7, the cylinder discrimination state 1 is set to “incomplete” and then the cylinder discrimination process 1 in FIG. 6 is executed, and the combination of the reference position signal and the cam angle signal is determined. If normal, cylinder discrimination may be resumed immediately.

The present invention can be applied not only to a gasoline engine but also to a vehicle using an internal combustion engine such as a diesel engine as a drive source.
Moreover, in the said embodiment, the function of a pattern determination means, a rotation position setting means, and a cylinder discrimination means is implement | achieved by ECU10 by which a function is specified by a control program. On the other hand, at least some of the functions of the plurality of means may be realized by hardware whose functions are specified by the circuit configuration itself.

  As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

10: ECU (engine control device, pattern determining means, rotational position setting means, cylinder determining means), 40: crank angle sensor, 60: cam angle sensor

Claims (5)

A crank angle signal having a reference position signal representing a predetermined angular position in a signal train generated at a predetermined angular interval with rotation of the crankshaft of the engine, and the reference position signal with rotation of the engine camshaft. The combination of the number of signals generated at the corresponding position and the reference position signal is determined based on a cam angle signal that differs for each reference position signal in one combustion cycle, and one combustion cycle is determined based on the crank angle signal. In the engine control device that sequentially updates the engine rotation position in
Pattern determination means for determining whether or not the previous and current generation patterns of the combination of the reference position signal and the cam angle signal are normal up to the current combination for the combination that is repeated a predetermined number of times;
When the determination result by the pattern determination means is normal, the engine rotation position in one combustion cycle is set based on the current combination, and when the determination result is not normal, the engine rotation position is not set. Setting means;
When the pattern determination means determines that the generated pattern is abnormal after the cylinder determination is completed when the engine is started and before the determination result is normal, the cylinder determination is resumed with the cylinder determination in an incomplete state. Means,
An engine control device comprising: 2. The engine control device according to claim 1 , wherein the cylinder determination unit restarts the cylinder determination when the determination result becomes normal after the cylinder determination is in an incomplete state. A crank angle signal having a reference position signal representing a predetermined angular position in a signal train generated at a predetermined angular interval with rotation of the crankshaft of the engine, and the reference position signal with rotation of the engine camshaft. The combination of the number of signals generated at the corresponding position and the reference position signal is determined based on a cam angle signal that differs for each reference position signal in one combustion cycle, and one combustion cycle is determined based on the crank angle signal. In the engine control device that sequentially updates the engine rotation position in
Pattern determination means for determining whether or not the previous and current generation patterns of the combination of the reference position signal and the cam angle signal are normal up to the current combination for the combination that is repeated a predetermined number of times;
When the determination result by the pattern determination means is normal, the engine rotation position in one combustion cycle is set based on the current combination, and when the determination result is not normal, the engine rotation position is not set. Setting means;
Equipped with a,
The rotational position setting means sets the engine rotational position based on the combination of each time until the determination result becomes normal after cylinder determination is completed at the time of engine start.
An engine control device characterized by that. A crank angle signal having a reference position signal representing a predetermined angular position in a signal train generated at a predetermined angular interval with rotation of the crankshaft of the engine, and the reference position signal with rotation of the engine camshaft. The combination of the number of signals generated at the corresponding position and the reference position signal is determined based on a cam angle signal that differs for each reference position signal in one combustion cycle, and one combustion cycle is determined based on the crank angle signal. In the engine control device that sequentially updates the engine rotation position in
Pattern determination means for determining whether or not the previous and current generation patterns of the combination of the reference position signal and the cam angle signal are normal up to the current combination for the combination that is repeated a predetermined number of times;
When the determination result by the pattern determination means is normal, the engine rotation position in one combustion cycle is set based on the current combination, and when the determination result is not normal, the engine rotation position is not set. Setting means;
Equipped with a,
The rotational position setting means sets the engine rotational position based on the combination of each time until the rotational speed of the engine becomes equal to or higher than a predetermined rotational speed after cylinder discrimination is completed at the time of engine start.
An engine control device characterized by that. The engine control apparatus according to any one of claims 1 to 4, wherein the pattern determination unit determines whether or not the generated pattern is normal a plurality of times in succession.

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