JP2013060938A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device applied for an engine using a valve timing adjustment device and determining an engine rotating position on the basis of a cum angle signal when a crank angle signal is abnormal.SOLUTION: The engine control device retards the valve timing adjustment device so that a cum shaft may rotate toward the most retarded angle position (S406) when the crank angle signal is abnormal (S400:YES) and the cum shaft advances to a crank shaft (S404:NO). The engine control device, in consideration of the remainder of a current estimated advance angle amount to a signal interval (30° CA) of a pseudo crank angle signal, sets the generation timing of an initial pseudo crank angle signal in a timer (S412), updates cylinder position information (S414-S418), and estimates an interval between the current and the next cum angle signals excluding the remainder of the current estimated advance angle amount (S422). The engine control device generates the pseudo crank angle signal in each 30° CA during the estimated cum angle signal interval.

Description

  The present invention is applied to an engine using a valve timing adjustment device that adjusts the opening / closing timing of a valve that opens and closes a camshaft, performs cylinder discrimination based on a crank angle signal and a cam angle signal, and based on the crank angle signal The present invention relates to an engine control device that counts engine rotation positions in one combustion cycle.

  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 predetermined angular position as the camshaft of the engine rotates. There is known an engine control device that performs cylinder discrimination based on the cam angle signal generated at the engine and counts the engine rotation position in one combustion cycle consisting of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke based on the crank angle signal. ing.

  In such an engine control device, when an abnormality occurs in the crank angle signal due to an abnormality in the crank angle sensor that detects the crank angle signal, a pseudo crank angle signal is generated at a predetermined angle interval based on the generation interval of the cam angle signal. It is known to determine the engine rotation position based on the pseudo crank angle signal (see, for example, Patent Documents 1 and 2).

JP 2000-104619 A JP 2002-195092 A

  In Patent Documents 1 and 2, since the rotational phase of the cam shaft with respect to the crank shaft is fixed, the angular position at which the cam angle signal is generated does not change. Therefore, even if the crank angle signal becomes abnormal, the engine rotational position can be determined based on the pseudo crank angle signal generated based on the cam angle signal generation interval and the generated angular position of the cam angle signal. Thereby, it is possible to burn the fuel in the corresponding cylinder.

  However, in the case of an engine that uses a valve timing adjusting device that adjusts the opening / closing timing of a valve that opens and closes the camshaft by controlling the rotational phase of the camshaft relative to the crankshaft, the cam angle signal generation angle position is It is variably controlled from the most retarded position, which is the reference position of the rotational phase of the shaft, to the advance side.

  Therefore, when the crank angle signal is abnormal, a pseudo crank angle signal is generated from the cam angle signal generation interval, and the pseudo crank angle signal is counted based on the cam angle signal generation position to determine the engine rotation position. There is a problem that the engine rotational position shifts when the angle is advanced.

  The present invention has been made to solve the above-described problems, and is applied to an engine using a valve timing adjusting device, and determines an engine rotation position based on a cam angle signal when a crank angle signal is abnormal. The purpose is to provide.

  According to the first to sixth aspects of the present invention, the reference position signal is applied to an engine using the valve timing adjusting device and represents a predetermined angular position in a signal train generated at predetermined angular intervals as the crankshaft rotates. An engine that performs cylinder discrimination based on a crank angle signal having a crank angle signal and a cam angle signal generated at a predetermined angular position as the cam shaft rotates, and counts the engine rotational position in one combustion cycle based on the crank angle signal In the control device, when the abnormality determination means determines that the crank angle signal is abnormal, the retard angle control means controls the valve timing adjusting device to rotate the camshaft to the most retarded angle position with respect to the crankshaft.

  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 rotation position represents the rotation position of the engine at the rotation angle of one combustion cycle, and the stroke position of each cylinder can be determined based on the engine rotation position.

  In this way, when the crank angle signal becomes abnormal and the rotational phase of the cam shaft relative to the crank shaft cannot be controlled based on the crank angle signal and the cam angle signal, the cam shaft is at the reference position relative to the crank shaft. By rotating to the retard position, the rotational phase of the camshaft relative to the crankshaft can be specified.

  Then, the signal generator means the amount of advance from the most retarded position of the cam shaft immediately before the abnormality judging means determines that the crank angle signal is abnormal, and the cam shaft is directed from the advanced position to the most retarded position. The pseudo crank angle signal is generated at predetermined pseudo angle intervals based on the amount of change in the retard angle during rotation.

  As described above, the timing at which the cam shaft reaches the most retarded position can be determined based on the cam shaft advance angle amount and the retard angle change amount immediately before it is determined that the crank angle signal is abnormal, and the cam angle signal Since the interval can be calculated, it is possible to determine the number of times to generate the pseudo crank angle signal having a predetermined pseudo angle interval in the cam angle signal interval.

  Then, the rotational position setting means sets the count value of the pseudo crank angle signal based on the cylinder discrimination information and the advance amount immediately before the abnormality determination means determines that the crank angle signal is abnormal, and sets the pseudo crank signal as the pseudo crank signal. Based on this, the engine rotation position is counted.

  Thus, the count value of the pseudo crank angle signal representing the engine rotational position is set based on the cylinder discrimination information and the advance amount immediately before the crank angle signal becomes abnormal, and the engine rotational position is determined based on the pseudo crank angle signal. Therefore, the engine rotational position can be determined in consideration of the rotational phase of the camshaft relative to the crankshaft until the camshaft rotates to the most retarded position.

  Thus, even if the crank angle signal becomes abnormal, the engine rotation position in one combustion cycle can be determined based on the pseudo crank angle signal. As a result, before the camshaft reaches the most retarded position, the corresponding cylinder can promptly inject and burn fuel at an appropriate timing in one combustion cycle. Therefore, even when the crank angle signal is abnormal, the engine can be continued to run the vehicle.

  According to the second aspect of the present invention, when the abnormality determining means determines that the crank angle signal is abnormal, the retard angle controlling means controls the valve timing adjusting device to hold the camshaft at the most retarded angle position.

  By maintaining the rotational phase of the cam shaft relative to the crankshaft at the most retarded position, the rotational phase of the cam shaft relative to the crankshaft can be fixed at the most retarded position. Thus, when the valve timing adjusting device adjusts the valve timing of the intake valve, it is possible to prevent the valve opening period of the intake valve and the exhaust valve from overlapping and to continue the operation of the engine.

  According to the third aspect of the present invention, the signal generating means determines the initial generation timing of the pseudo crank angle signal based on the advance amount of the cam shaft immediately before the abnormality determining means determines that the crank angle signal is abnormal. decide.

  Thereby, for example, when a fraction less than the pseudo-angle interval for generating the pseudo crank angle signal is generated in the advance amount from the most retarded position of the cam shaft, the pseudo crank angle signal is generated by waiting for this fraction. If started, the generation timing of the pseudo crank angle signal can be matched with the most retarded position. As a result, the engine rotational position can be counted based on the most retarded angle position, which is the reference for the rotational phase of the camshaft relative to the crankshaft.

According to the fourth aspect of the present invention, the signal generating means calculates the time interval for generating the pseudo crank angle signal by converting the angle interval of the cam angle signal into a time.
Thus, based on the time interval of the cam angle signal, the time interval for generating the pseudo crank angle signal so as to be a predetermined pseudo angle interval can be calculated according to the ratio of the cam angle signal to the angle interval.

  According to the fifth aspect of the present invention, each time the cam angle signal is detected, the signal generation means detects the angular interval of the cam angle signal between the current time and the next time based on the advance amount and the retard angle change amount of the cam shaft. And a pseudo crank angle signal is generated based on the calculated angular interval of the cam angle signal.

  As a result, when the angular interval of the cam angle signal during the rotation of the cam shaft to the most retarded angle position changes, a pseudo crank angle signal can be generated based on the angular interval of the cam angle signal between the current time and the next time. .

  According to the sixth aspect of the invention, the rotational position setting means detects the pseudo crank angle signal based on the cylinder discrimination information and the advance amount when the cam angle signal is detected every time the cam angle signal is detected. Set the count value.

  As a result, even if the cam angle signal is detected while the camshaft is rotating toward the most retarded position and the camshaft is advanced relative to the crankshaft, the cylinder discrimination information and the advancement amount at that time are detected. Based on the above, the engine rotation position can be reset.

  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. The system block diagram which shows the phase control of a valve timing adjustment apparatus. The time chart which shows the cam angle signal at the time of normal, a crank angle signal, and fuel injection and ignition control. The time chart which shows the cam angle signal at the time of abnormality, a crank angle signal, and fuel injection and ignition control. The flowchart which shows the pseudo crank angle signal generation process at the time of cam angle signal detection. The flowchart which shows a pseudo crank angle signal generation process.

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 three-cylinder gasoline engine and ignition control of a spark plug, and includes a CPU 12, a ROM 14, a RAM 16, an SRAM (standby RAM) 18, an EEPROM 20, an input circuit 30, and an output circuit. 32 or the like. Further, the ECU 10 controls a valve timing adjusting device (hereinafter also referred to as “VVT device”) 40 (see FIG. 2) that variably adjusts the opening / closing timing of the intake valve as a valve that opens and closes the camshaft 50 (see FIG. 2). To do.

  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, ignition plug ignition control, and VVT device 40 phase control (not shown) are output via the output circuit 32.

As shown in FIG. 2, the VVT device 40 is installed in a torque transmission system that transmits the torque of the crankshaft to the camshaft 50, and controls the rotational phase of the camshaft 50 relative to the crankshaft to the advance side or the retard side. . The ECU 10 performs duty control on a current value supplied to an OCV (Oil Control Valve) 60, thereby causing each of the retarded side and advanced side hydraulic chambers and the oil supply side or oil discharge of the VVT device 40 through the oil passage 100. And the rotational phase of the camshaft 50 with respect to the crankshaft is controlled.

The ECU 10 controls the rotation phase of the camshaft 50 with respect to the crankshaft, thereby adjusting the opening / closing timing at which the cam 52 provided on the camshaft 50 opens and closes the intake valve.
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.

(Cylinder discrimination)
The ECU 10 has 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 rotates, and a predetermined angular position as the camshaft 50 rotates. Cylinder discrimination is performed based on the generated cam angle signal, and the engine rotation position in one combustion cycle including the intake stroke, compression stroke, expansion stroke, and exhaust stroke is determined based on the crank angle signal.

  The crank angle signal is generated when a crank angle sensor (not shown) detects teeth formed at a predetermined angular interval (for example, 10 °) on the outer periphery of a crank rotor fixed to the crankshaft as the crankshaft rotates. To do.

  The interval between teeth formed on the outer periphery of the crank rotor is not limited to 10 °, and may be smaller or larger than 10 °. In the middle of the tooth row of the crank rotor, a missing tooth continuous missing piece 200 (see FIG. 3) in which two teeth are continuously missing at two places across one tooth and one tooth at two places. A single missing portion 202 (see FIG. 3) missing in step 1 is formed on a side opposite to 180 ° as a predetermined angular position. The crank angle signal when detecting the continuous chip 200 and the single chip 202 serves as a reference position signal when performing cylinder discrimination and setting the engine rotation position in one combustion cycle.

  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.

  Since the camshaft 50 rotates at a ratio of 1/2 with respect to the crankshaft, the camshaft 50 rotates once while the crankshaft rotates twice (720 ° CA). The cam angle signal is formed on the outer periphery of the cam fixed to the camshaft 50, corresponding to a three-cylinder engine, at a cam tooth 210 (a cam rotor angle of 120 °) with a predetermined angular position of 240 ° CA. 3) is generated when a cam angle sensor (not shown) detects the rotation of the cam shaft 50. In FIG. 3, the position of the cam teeth 210 indicated by a solid line indicates that the cam shaft 50 is at the most retarded position with respect to the crankshaft, and the position of the cam teeth 210 indicated by a dotted line is applied to the crankshaft by the VVT device 40. In contrast, the camshaft 50 is advanced.

  When the rotational phase of the camshaft 50 is adjusted to the most retarded angle position with respect to the crankshaft, in this embodiment, as shown in FIG. It is configured to reach dead center). When the rotation phase of the camshaft 50 relative to the crankshaft is adjusted by the VVT device 40, the position of the cam teeth 210 advances from the most retarded position as indicated by the dotted line. Therefore, the compression TDC is reached after the cam teeth 210 are detected (30 ° CA + advance amount).

  The ECU 10 determines which cylinder of the three cylinders corresponds to the next compression TDC in which the cam teeth 210 are detected based on the combination of the crank angle signal continuous lack 200 and single missing 202 and the cam teeth 210. When the cam teeth 210 are detected within the angle range in which the continuous chip 200 is detected, the next compression TDC is the second cylinder. When the cam teeth 210 are detected after the single chip 202 is detected, the next compression TDC is the third cylinder. If the cam teeth 210 are not detected within the angle range in which the continuous lack 200 is detected, the next compression TDC when the cam teeth 210 are detected is the first cylinder.

  When the ECU 10 determines the cylinder based on the combination of the crank angle signal continuous missing portion 200 and single missing portion 202 and the cam tooth 210, the ECU 10 corresponds to the next compression TDC every time the cam tooth 210 is detected as shown in FIG. The cylinder position information representing the cylinder to be updated is updated based on the cylinder discrimination information.

(Engine rotation position)
At the start of the engine, the rotational phase of the camshaft is fixed at the most retarded position. Therefore, when the cam angle signal is detected at the time of engine start, the compression TDC of any cylinder is reached after 30 ° CA. Therefore, when the ECU 10 determines the cylinder based on the combination of the crank angle signal continuous missing part 200 and the single missing part 202 and the cam teeth 210 at the time of starting the engine, the ECU 10 detects the corresponding cylinder after 30 ° CA when the cam angle signal is detected. The count value of the reference cylinder counter is set so that the count value corresponds to the compression TDC.

  The ECU 10 sets the count value of the reference cylinder counter when detecting the cam angle signal so that it is 0 in the compression TDC of the first cylinder, 8 in the compression TDC of the second cylinder, and 16 in the compression TDC of the third cylinder. . That is, the count value of the reference cylinder counter represents the stroke position of each cylinder in one combustion cycle, that is, the engine rotation position.

  When the ECU 10 executes cylinder discrimination at the time of engine start and sets the count value of the reference cylinder counter, the ECU 10 sets a reference cylinder counter for counting the engine rotation position every 30 ° CA based on a crank angle signal detected every 10 ° CA. +1 count up. When the value of the reference cylinder counter is 24, the total angle is 720 ° CA, so the count value is returned to zero.

  Based on the count value of the reference cylinder counter, the ECU 10 sets the fuel injection timing by the injector and the ignition timing by the spark plug to timings suitable for the engine operating state.

(Rotation position setting process)
Next, the rotational position setting process executed by the ECU 10 when the CPU 12 executes a control program stored in the ROM 14 or the like will be described.

  If an abnormality occurs in the crank angle signal due to a failure of the crank angle sensor and the crank angle signal is not output as shown in FIG. 4, the rotation phase of the camshaft 50 relative to the crankshaft is fixed at the most retarded position. Based on the cam angle signal interval generated at 240 ° CA, a pseudo crank angle signal is generated every 30 ° CA similarly to the count interval of the reference cylinder counter, and the reference cylinder is based on the detection timing of the cam teeth 210. The reference cylinder counter can be counted based on the pseudo crank angle signal by setting the count value of the counter.

  However, in this embodiment, since the rotational phase of the camshaft 50 relative to the crankshaft is variably adjusted by the VVT device 40, if the count value of the reference cylinder counter is set based on the detection timing of the cam teeth 210, the cam The engine rotational position is shifted by the advance amount from the most retarded position of the shaft 50. As described above, when the engine rotational position shifted by the advance amount is used, fuel cannot be injected and burned at an appropriate timing in the corresponding cylinder.

  Therefore, in the present embodiment, even when an abnormality occurs in the crank angle signal in the configuration in which the rotation phase of the camshaft 50 with respect to the crankshaft is adjusted by the VVT device 40, the flowchart of the rotational position setting process shown in FIGS. In this cylinder, fuel is injected and burned at an appropriate timing.

  FIG. 5 is a process executed every time a cam angle signal is detected by the cam teeth 210, and FIG. 6 is a process executed every time a pseudo crank angle signal generated when the crank angle signal is abnormal is detected. is there.

(When cam angle signal is detected)
When the cam angle signal is detected, in S400 of FIG. 5, the ECU 10 determines whether or not the crank angle signal is abnormal. The crank angle signal is determined to be abnormal when, for example, the level of the crank angle signal is fixed to “low” or “high”.

  When the crank angle signal is normal (S400: No), the ECU 10 discriminates the cylinder that will next undergo compression TDC based on the crank angle signal and the cam angle signal, and updates the cylinder position information based on this cylinder discrimination information. (S402).

  When the crank angle signal is abnormal (S400: Yes), the ECU 10 determines whether or not the current estimated advance angle amount from the most retarded position of the cam shaft 50 when the current cam angle signal is detected is zero. (S404). When the ECU 10 determines for the first time that the crank angle signal is abnormal, the ECU 10 determines whether the cam angle relative to the crankshaft is based on the phase difference between the crank angle signal and the cam angle signal immediately before the crank angle signal is determined to be abnormal. The current estimated advance amount of the axis 50 is calculated. In the time chart shown in FIG. 4, the current estimated advance amount when it is first determined that the crank angle signal is abnormal is 50 ° CA.

  When the estimated advance angle amount is not 0 this time (S404: No), the ECU 10 performs duty control on the current value supplied to the OCV 60, and causes the VVT device 40 to rotate so that the camshaft 50 rotates toward the most retarded position. Delay angle control is performed (S406). That is, the ECU 10 executes the retard angle control in S406 until the current estimated advance angle amount becomes 0 and the camshaft 50 reaches the maximum retard position.

  When the camshaft 50 reaches the most retarded position, the ECU 10 holds the camshaft 50 at the most retarded position. As a result, it is possible to prevent the valve opening periods of the exhaust valve and the intake valve from overlapping, so that even if the crank angle signal is abnormal, the operation of the engine can be continued and the vehicle can be retreated.

  Next, in order to set the generation timing of the pseudo crank angle signal that is generated first after detecting the cam angle signal, the initial pseudo crank angle signal angle (TCAM) is calculated by the following equation (1) (S408), The process proceeds to S412.

The remainder of TCAM = (current estimated advance angle / 30 ° CA) (1)
In the present embodiment, as described above, the signal interval of the pseudo crank angle signal is set to 30 ° CA, which is the same as the count interval of the reference cylinder counter, so that TCAM is 30 ° CA with respect to the current estimated advance amount. The remainder is a fraction. In the example shown in FIG. 4, since the estimated advance angle amount is 50 ° CA as described above, the TCAM calculated from the equation (1) is 20 ° CA.

If the estimated advance amount is 0 (S404: Yes), that is, if the camshaft 50 is at the most retarded position, the ECU 10 sets TCAM to 0 (S410), and the process proceeds to S412.
When TCAM is set in S408 or S410, the ECU 10 determines the time interval of 30 ° CA based on the time interval of the cam angle signal interval (T) between the previous time and the current time obtained by measuring with a timer or the like and converting the time. The time interval of the pseudo crank angle signal to be generated is calculated from the angle ratio of 30 ° CA to the cam angle signal interval (T). The ECU 10 constantly measures the time interval between the previous and current cam angle signal intervals (T) with a timer or the like in order to convert the cam angle signal interval (T) into time.

  Further, the TCAM is converted into a time based on the time interval of the pseudo crank angle signal, and the conversion result is set in the pseudo crank angle signal output timer (S412). If the advance amount of the camshaft immediately before the crank angle signal becomes abnormal is held, the cam angle signal interval (T) between the previous time and the current time when the crank angle signal is determined to be abnormal for the first time is 240 ° CA.

  When the TCAM time set in the pseudo crank angle signal output timer elapses, the first pseudo crank angle signal after the cam angle signal is detected is output. Then, in the process of FIG. 6 described later, a pseudo crank angle signal is generated at an interval of 30 ° CA following the first pseudo crank angle signal, and the reference cylinder counter is counted.

  Thus, by generating a pseudo crank angle signal in consideration of a fraction of 30 ° CA with respect to the currently estimated advance amount, the generation timing of the pseudo crank angle signal coincides with the most retarded position. Thereby, in the process of FIG. 6 to be described later, the reference cylinder counter representing the engine rotation position can be counted based on the most retarded position.

  If the current cylinder position information is 1 or 2 other than 3 (S414: No), the ECU 10 increments the cylinder position information by 1 (S416), and if the current cylinder position information is 3 (S414). : Yes), the cylinder position information is set to 1 (S418), and the process proceeds to S420.

  The delay change amount by which the camshaft 50 rotates to the retard side by the retard control in S406 after the cam angle signal is detected this time until the next cam angle signal is detected is the cam angle signal interval between the previous time and the current time ( T) and the current estimated advance amount.

  Therefore, the ECU 10 moves the cam shaft 50 to the retard side by the retard control in S406 until the next cam angle signal is detected based on the cam angle signal interval (T) between the previous time and the current time and the current estimated advance amount. The amount of retardation change to rotate is calculated from a map or the like (S420). When the camshaft 50 is at the most retarded position, the retard change amount is zero.

In the example of FIG. 4, since the cam shaft 50 has reached the most retarded position when the cam angle signal is detected next time, the retard change amount is 50 ° CA, which is the same as the currently estimated advance angle amount.
The interval between the time when the cam angle signal is detected and the pseudo crank angle signal is output for the first time after TCAM elapses until the next cam angle signal is detected while the camshaft 50 is retarded. A certain estimated cam angle signal interval is calculated by the following equation (2) (S422).

Estimated cam angle signal interval = 240 ° CA + retard angle change amount-TCAM (2)
The estimated cam angle signal interval calculated by the equation (2) is the pseudo crank angle signal excluding the TCAM calculated in S408 or S410 between the detection of the current cam angle signal and the detection of the next cam angle signal. It represents the angular interval to be generated.

  In the example of FIG. 4, the retardation change amount is 50 ° CA and TCAM is 20 ° CA, so the estimated cam angle signal interval is 270 ° CA. When the camshaft 50 is at the most retarded position, the estimated cam angle signal interval is 240 ° CA.

  The ECU 10 subtracts the retardation change amount calculated in S420 from the current estimated advance angle amount, detects the cam angle signal next time, and sets it as the current estimated advance angle amount used when this routine is executed (S424). In the example of FIG. 4, since the cam shaft 50 has reached the most retarded position when the cam angle signal is detected next time, the current estimated advance amount calculated in S424 is 0 ° CA.

(When detecting pseudo crank angle signal)
When the pseudo crank angle signal is detected, the ECU 10 determines in S430 in FIG. 6 whether or not the current process is the first process executed first after the cam angle signal is detected. That is, it is determined whether or not a pseudo crank angle signal is first detected after the cam angle signal is detected.

  If it is not the first process after the cam angle signal is detected (S430: No), the ECU 10 increments the reference cylinder counter by 1 (S432), and if the count value of the reference cylinder counter exceeds 23 (S434: Yes), the reference The cylinder counter is set to 0 (S436), and the process proceeds to S446.

  In the case of the initial process after the cam angle signal is detected (S430: Yes), the ECU 10 sets the count value of the reference cylinder counter according to the following equations (3) to (5) according to the cylinder position information (S440, S442, S444)). In equations (3) to (5), [] is a Gaussian symbol and represents the maximum integer that does not exceed the numerical value in the symbol.

When cylinder position information = 1 Reference cylinder counter = 24 − ([current advance amount / 30 ° CA] +1) (3)
When cylinder position information = 2 Reference cylinder counter = 8 − ([current advance amount / 30 ° CA] +1) (4)
When cylinder position information = 3 Reference cylinder counter = 16 − ([current advance amount / 30 ° CA] +1) (5)
When the reference cylinder counter is set in S440, S442, and S444, the ECU 10 determines whether or not the estimated cam angle signal interval is 30 ° CA or more (S446). When the estimated cam angle signal interval is less than 30 ° CA (S446: No), the ECU 10 ends this process.

  When the estimated cam angle signal interval is 30 ° CA or more (S446: Yes), the ECU 10 subtracts 30 ° CA from the estimated cam angle signal interval (S448). Then, the ECU 10 simulates a time corresponding to an angle ratio of 30 ° CA with respect to the cam angle signal interval (T) by measuring with a timer or the like and converting the cam angle signal interval (T) between the previous time and the current time. The crank angle signal output timer is set (S450), and this process is terminated.

  Thus, even if the crank angle signal is abnormal, the cam angle signal interval between the previous time and the current time is converted to time, and the pseudo crank angle signal output timer is set to 30 ° CA based on the angle ratio to the cam angle signal interval. By setting the corresponding time, a pseudo crank angle signal can be generated every 30 ° CA.

  The process of FIG. 6 is executed every time the pseudo crank angle signal is detected, and each time the ECU 10 subtracts 30 ° CA from the estimated cam angle signal interval, the interval between the estimated cam angle signal intervals calculated in S422 of FIG. , Pseudo crank angle signals are generated at 30 ° CA intervals.

  In the embodiment described above, the count value of the reference cylinder counter representing the engine rotation position is set based on the cylinder discrimination information immediately before the crank angle signal becomes abnormal and the current estimated advance amount. Further, the estimated cam angle signal is based on the fraction of 30 ° CA, which is the signal interval of the pseudo crank angle signal, with respect to the current estimated advance angle amount and the amount of change in the retard angle of the cam shaft 50 until the next cam angle signal is detected. The interval is calculated, and the number of generations of the pseudo crank angle signal is determined based on the estimated cam angle signal interval.

  As a result, even if the crank angle signal becomes abnormal in the engine using the VVT device 40, the rotational phase of the camshaft 50 with respect to the crankshaft is taken into consideration, and the engine rotational position in one combustion cycle based on the count value of the reference cylinder counter Can be determined. As a result, before the camshaft reaches the most retarded position, the corresponding cylinder can promptly inject and burn fuel at an appropriate timing in one combustion cycle. Therefore, even when the crank angle signal is abnormal, the engine can be continued to run the vehicle.

  In the process of FIG. 5, the process of S400 corresponds to the function executed by the abnormality determination means of the present invention, the process of S406 corresponds to the function executed by the retard angle control means of the present invention, and the process of S412 corresponds to the function of the present invention. This corresponds to the function executed by the signal generation means.

  In the processing of FIG. 6, the processing of S430 to S444 corresponds to the function executed by the rotational position setting means of the present invention, and the processing of S446 to S450 corresponds to the function of the signal generation means of the present invention.

The ECU 10 corresponds to the engine control device of the present invention, and realizes functions executed by the abnormality determination means, the retard control means, the signal generation means, and the rotational position setting means of the present invention.
[Other Embodiments]
In the above embodiment, when the cam angle signal is detected and the pseudo crank angle signal is first generated, only the TCAM that is a fraction of 30 ° CA that is the signal interval of the pseudo crank angle signal with respect to the currently estimated advance angle amount. A pseudo crank angle signal is generated after waiting.

  On the other hand, even if the current estimated amount of advancement includes a fraction of 30 ° CA, the pseudo crank angle signal may be generated without waiting for the fraction. The engine rotational position determined based on the pseudo crank angle signal is deviated by a fraction of the estimated advance angle amount this time, but the deviation is in a range of less than 30 ° CA. Therefore, the accuracy of the engine rotation position is lowered, but the vehicle can be retreated.

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. Further, the number of cylinders of the engine is not limited to three cylinders.
In the above embodiment, the functions of the abnormality determination unit, the retard angle control unit, the signal generation unit, and the rotational position setting unit are realized by the ECU 10 whose functions are specified by the 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, abnormality determination means, retard angle control means, signal generation means, rotational position setting means), 50: camshaft

Claims (6)

This is applied to an engine using a valve timing adjusting device that adjusts the opening / closing timing of a valve that opens and closes the camshaft by controlling the rotational phase of the camshaft with respect to the crankshaft, and at predetermined angular intervals as the crankshaft rotates. Cylinder discrimination is performed based on a crank angle signal having a reference position signal representing a predetermined angular position in a generated signal sequence and a cam angle signal generated at a predetermined angular position as the cam shaft rotates. In an engine control device that counts the engine rotation position in one combustion cycle based on a crank angle signal,
Abnormality determining means for determining abnormality of the crank angle signal;
When the abnormality determination means determines that the crank angle signal is abnormal, the angle control means controls the valve timing adjusting device to rotate the camshaft to the most retarded position with respect to the crankshaft;
The advance amount of the cam shaft from the most retarded position immediately before the abnormality determining means determines that the crank angle signal is abnormal, and the cam shaft from the advanced position toward the most retarded position. A signal generating means for generating a pseudo crank angle signal at a predetermined pseudo angle interval based on the amount of change in retardation when rotating;
A count value of the pseudo crank angle signal is set based on the cylinder discrimination information and the advance amount immediately before the abnormality determining means determines that the crank angle signal is abnormal, and the count value of the pseudo crank angle signal is set based on the pseudo crank angle signal. Rotational position setting means for counting the engine rotational position;
An engine control device comprising:   The delay angle control means controls the valve timing adjusting device to hold the camshaft at the most retarded angle position when the abnormality determination means determines that the crank angle signal is abnormal. The engine control apparatus according to claim 1.   The signal generation means determines an initial generation timing of the pseudo crank angle signal based on the advance amount of the cam shaft immediately before the abnormality determination means determines that the crank angle signal is abnormal. The engine control apparatus according to claim 1 or 2, characterized in that   The engine according to any one of claims 1 to 3, wherein the signal generation means calculates a time interval for generating the pseudo crank angle signal by converting an angular interval of the cam angle signal into a time. Control device.   The signal generating means calculates an angular interval of the cam angle signal between the current time and the next time based on the advance angle amount and the retard angle change amount of the cam shaft each time the cam angle signal is detected, 5. The engine control device according to claim 1, wherein the pseudo crank angle signal is generated based on the calculated angular interval of the cam angle signal. 6.   The rotational position setting means sets the count value of the pseudo crank angle signal based on the cylinder discrimination information and the advance amount when the cam angle signal is detected every time the cam angle signal is detected. The engine control device according to any one of claims 1 to 5, wherein

Images