JP5912948B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a technical field of a control device for an internal combustion engine that controls an internal combustion engine mounted on a vehicle such as a hybrid vehicle.

  An internal combustion engine mounted on a vehicle may be provided with a rotation angle sensor that detects a rotation angle of a crankshaft of the internal combustion engine. As a method for increasing the accuracy of the detected value by the rotation angle sensor, a technique for correcting a deviation of the detected value (that is, a difference between the detected value and the actual value) is known. For example, Patent Document 1 proposes an apparatus that learns an error of a rotation angle sensor signal when motoring is at a constant rotation.

  The rotation angle of the internal combustion engine detected by the rotation angle sensor is used, for example, to determine the combustion state (specifically, misfire, etc.) of the internal combustion engine. When determining the combustion state of the internal combustion engine, various methods are used in order to obtain a more accurate determination result. For example, Patent Document 2 proposes a technique for invalidating misfire determination when a damper slip is detected in a device that determines misfire based on the output of a rotation angle sensor. Patent Document 3 proposes a technique of performing misfire diagnosis after learning mechanical variations and combustion variations among a plurality of cylinders.

JP 2005-351138 A JP 2009-281189 A Japanese Patent Laid-Open No. 08-261130

  According to the study of the present inventor, when the rotation angle sensor is temporarily removed and reassembled, the rotation angle is changed due to a change in the clearance between the sensor center and the sensor rotor center. It has been found that there may be a deviation in the detected value. That is, even if the rotation angle sensor is in a state where an accurate value can be detected before removal, there is a possibility that an accurate value cannot be detected after removal (that is, after reattachment). .

  However, Patent Documents 1 to 3 do not mention any deviation of the detection value caused by the above-described removal. For this reason, in the techniques described in Patent Documents 1 to 3, even if the detection value is deviated by removing the rotation angle sensor, it cannot be detected that the deviation has occurred. Alternatively, even if the occurrence of deviation can be detected, the deviation cannot be corrected appropriately. As a result, there arises a technical problem that various controls of the internal combustion engine based on the detection value of the rotation angle sensor cannot be properly executed, such as the combustion state of the internal combustion engine cannot be accurately determined.

  The present invention has been made in view of, for example, the above-described problems. Even when the detected value is deviated due to the removal of the rotation speed sensor, inappropriate control is executed. It is an object of the present invention to provide a control device for an internal combustion engine that can be prevented.

In order to solve the above-described problems, a control device for an internal combustion engine of the present invention is mounted on a vehicle including an internal combustion engine and an electric motor as a power source, and a rotation angle detection unit that detects a rotation angle of the internal combustion engine; A combustion state estimating means for estimating the combustion state of the internal combustion engine based on the determined rotation angle; an angle deviation detecting means for detecting that an angular deviation has occurred in the rotation angle detecting means; and the angle deviation is detected. At least one of control for prohibiting estimation of the combustion state of the internal combustion engine, reset control of the learning value of the rotation angle detecting means, and control for prohibiting control using the estimated combustion state and a control execution unit that, the angle deviation detection means, a torque estimating means for estimating the torque of a plurality of cylinders, wherein the internal combustion engine has with the angular acceleration of the internal combustion engine cylinder, before An electric motor angular acceleration detecting means for detecting an angular acceleration of the electric motor, a torque variation width between a plurality of cylinders in the internal combustion engine is larger than a predetermined first threshold value, and a variation width of the angular acceleration of the electric motor is a predetermined first value. And a first angle deviation determination unit that determines that the angle deviation has occurred when the angle is smaller than two threshold values .

  A vehicle on which the control device for an internal combustion engine of the present invention is mounted is a hybrid vehicle including an internal combustion engine and an electric motor as power sources. The internal combustion engine is configured as, for example, a gasoline engine having a plurality of cylinders, but is not particularly limited with respect to fuel type, fuel supply mode, fuel combustion mode, intake / exhaust system configuration, cylinder arrangement, and the like. The electric motor is configured as a motor / generator, for example, and is connected to the output shaft of the internal combustion engine via various gears such as a planetary gear mechanism.

  During operation of the control device for an internal combustion engine of the present invention, the rotation angle of the internal combustion engine is detected by a rotation angle detection means including, for example, a crank angle sensor. When the rotation angle of the internal combustion engine is detected, the combustion state of the internal combustion engine is estimated by the combustion state estimation means. The combustion state estimation means stores, for example, a threshold value for determining misfire in the internal combustion engine, and determines whether or not the internal combustion engine has misfired by comparing the detected rotation angle with the threshold value. Note that the parameter used for estimating the combustion state may be the rotation angle itself of the internal combustion engine, or a parameter calculated from the rotation angle of the internal combustion engine (for example, fluctuation in the rotation speed or time required for rotation at a predetermined angle). Etc.).

  Here, particularly in the present invention, when the rotation angle of the internal combustion engine described above is detected, the occurrence of the angle deviation in the rotation angle detection means is monitored by the angle deviation detection means. Here, the “angle shift” refers to a state in which an unacceptable difference has occurred between the rotation angle value detected by the rotation angle detection means and the actual rotation angle value. Such a difference may occur due to, for example, a change in clearance caused by temporarily removing a sensor included in the rotation angle detection means. The angle deviation detection means may detect the angle deviation directly from, for example, a signal output from the rotation angle detection means, or indirectly detect the angle deviation from other parameters depending on the rotational speed of the internal combustion engine. It may be detected.

  When an angular deviation is detected in the rotation angle detection means, the control execution means performs control for prohibiting estimation of the combustion state of the internal combustion engine, reset control of the learning value of the rotation angle detection means, and control using the estimated combustion state. At least one of the prohibition controls is executed. Note that the “inhibition control for estimating the combustion state of the internal combustion engine” here is control for temporarily stopping the estimation of the combustion state by the combustion state estimating means. The “reset control of the learning value of the rotation angle detection means” is control for resetting a learning value (in other words, a correction value) applied to the detection value of the rotation angle detection means to an initial value. Further, the “control prohibition control using the estimated combustion state” means that various operation controls (for example, fuel injection control) in the internal combustion engine based on the combustion state estimated by the combustion state estimation means are at least temporarily. This is the control to stop.

  If each control described above is not executed, various problems may occur due to the incorrect value of the rotation angle detected by the rotation angle detection means. For example, since the erroneous rotation angle continues to be detected, the combustion state of the internal combustion engine cannot be accurately estimated by the combustion state estimation means. Furthermore, since the combustion state is not accurately estimated, various controls based on the combustion state cannot be appropriately executed.

  However, in the present invention, as described above, the control execution unit performs the control for prohibiting estimation of the combustion state of the internal combustion engine, the control for resetting the learning value of the rotation angle detection unit, and the control for prohibiting control using the estimated combustion state. Of these, at least one control is executed. Thereby, generation | occurrence | production of the malfunction mentioned above can be prevented suitably. Specifically, by executing the “inhibition control for estimating the combustion state of the internal combustion engine”, it is possible to prevent the combustion state of the internal combustion engine from being estimated as incorrect. In addition, by performing “reset control of the learning value of the rotation angle detection means”, it is possible to prevent an inaccurate number of rotations from being continuously detected. In this case, it is preferable that learning is executed again (that is, an appropriate learning value is newly calculated). Furthermore, by executing “prohibition control of control using the estimated combustion state”, improper control based on the combustion state is executed even when an incorrect combustion state is estimated. Can be prevented.

  As described above, according to the control apparatus for an internal combustion engine of the present invention, improper control is executed even when an angular deviation occurs in the rotation angle of the internal combustion engine detected by the rotation angle detection means. Can be prevented.

  In one aspect of the control apparatus for an internal combustion engine of the present invention, the angle deviation detection means includes torque estimation means for estimating torque of a plurality of cylinders of the internal combustion engine for each cylinder using angular acceleration of the internal combustion engine, and An electric motor angular acceleration detecting means for detecting an angular acceleration of the electric motor, a torque variation width between a plurality of cylinders in the internal combustion engine is larger than a predetermined first threshold value, and a variation width of the angular acceleration of the electric motor is a predetermined first value. And a first angle deviation determination unit that determines that the angle deviation has occurred when the angle is smaller than two threshold values.

  According to this aspect, at the time of the angle deviation detecting operation by the angle deviation detecting means, the torque of the plurality of cylinders included in the internal combustion engine is first estimated for each cylinder by the torque estimating means. The torque for each cylinder is estimated using the angular acceleration of the internal combustion engine. On the other hand, the motor angular acceleration detecting means detects the angular acceleration of the motor. Then, the first angle deviation determination means determines whether or not there is an angle deviation in the rotation angle detection means, using the detected torque of the internal combustion engine and the angular acceleration of the electric motor. Hereinafter, the determination of the angle deviation by the first angle deviation determination means will be described in detail.

  The torque detected for each cylinder is determined whether or not its variation width is larger than a predetermined first threshold value. Here, the “first threshold value” is set as an index for determining whether or not an angular deviation has occurred in the rotation angle detection means, and the estimated torque variation width is When it is larger than the first threshold value, it is determined that there is a possibility that an angular deviation has occurred in the rotation angle detection means.

  More specifically, when an angular deviation occurs in the rotational angle detected by the rotational angle detection means, a deviation also occurs in the angular acceleration of the internal combustion engine, and as a result, the torque estimated using the angular acceleration of the internal combustion engine is increased. The variation width also increases. Therefore, when the variation width of the torque is larger than the first threshold value, there is a possibility that an angular deviation has occurred in the rotation angle detecting means. However, since there is a possibility that the torque actually varies from cylinder to cylinder, it cannot be said that the angular deviation is surely generated only by the estimated torque of the internal combustion engine.

  On the other hand, it is determined whether or not the detected angular acceleration of the motor has a variation width smaller than a predetermined second threshold value. Here, the “second threshold value” is a threshold value for determining whether or not the variation in the estimated torque for each cylinder is caused by the angular deviation of the rotation angle detection means, and the angle of the motor When the variation width of the acceleration is smaller than the second threshold value, it is determined that the variation in the estimated torque is caused by the angular deviation.

  More specifically, if the torque of the internal combustion engine actually varies greatly from cylinder to cylinder, the torque fluctuations are also transmitted to the motor, so the angular acceleration of the motor also varies greatly. Therefore, when the variation in the angular acceleration of the electric motor is smaller than the second threshold value, it can be determined that the actual torque of the internal combustion engine does not vary. When the variation in the torque of the internal combustion engine is larger than the first threshold value and the angular acceleration of the electric motor is smaller than the second threshold value, the torque estimated even though the torque of the internal combustion engine does not actually vary. It can be said that there is a large variation. For this reason, it can be determined that the estimated torque variation is not an actual torque variation but is caused by an erroneous rotation angle detection (that is, an angular deviation occurs in the rotation angle detection means).

  In this aspect, as described above, it is possible to detect the occurrence of angular deviation based on the torque variation for each cylinder of the internal combustion engine and the angular acceleration variation of the electric motor. For this reason, in this aspect, even when the internal combustion engine is in a burning state (that is, in a firing state), it is possible to detect the angular deviation suitably. In particular, in the fired state, for example, the internal combustion engine rotates at a higher speed than in the motoring state, and therefore, an angular deviation due to twisting of the crankshaft or the like may occur. Therefore, it can be said that this aspect that can detect the angular deviation even in the firing state is extremely useful.

  In the aspect in which the angle deviation detection unit includes the first angle deviation determination unit, the torque is the largest among the plurality of cylinders when the first angle deviation determination unit determines that the angle deviation has occurred. A predetermined correction amount is subtracted from the detected rotation angle when the torque of the cylinder is calculated, and the detected rotation angle when the torque of the cylinder having the smallest torque among the plurality of cylinders is calculated is set to the detected rotation angle. You may comprise so that the rotation angle correction | amendment means which adds a predetermined correction amount may be provided.

  In this case, when it is determined that the angular deviation has occurred in the rotation angle detection means, a predetermined correction amount is subtracted from the rotation angle when the torque of the cylinder having the largest torque among the plurality of cylinders is calculated. Further, a predetermined correction amount is added to the rotation angle when the torque of the cylinder having the smallest torque among the plurality of cylinders is calculated. The “correction amount” here is set in advance as an appropriate value for fine adjustment of the rotation angle.

  Here, in particular, the estimated torque for each cylinder is estimated to be large because the angular acceleration of the internal combustion engine is calculated to be large, and the detected rotation angle of the internal combustion engine is shifted to the larger one. Show. On the other hand, the estimated torque for each cylinder is estimated to be small because the angular acceleration of the internal combustion engine is calculated to be small, indicating that the detected rotation angle of the internal combustion engine is shifted to a smaller one.

  Therefore, as described above, if the correction amount is subtracted from the rotation angle when the estimated torque is calculated to be the largest, and the correction amount is added to the rotation angle when the estimated torque is calculated to be the smallest, a plurality of cylinders can be obtained. The variation width of the estimated torque between the two becomes small. In other words, the angle deviation in the rotation angle detecting means is reduced. Therefore, the value detected by the rotation angle detecting means can be brought close to an accurate value.

  In the aspect in which the correction amount is subtracted and added, the rotation angle correction means has caused the angle deviation by the first angle deviation determination means in spite of performing the correction amount subtraction and addition. If determined, the correction amount may be increased by a predetermined value and the correction amount may be subtracted and added again.

  If comprised in this way, the correction amount used for the subtraction and addition with respect to a rotation angle will be enlarged in steps of a predetermined value until it determines with the angle deviation having been eliminated. Note that the “predetermined value” here is set in advance as a value for gradually bringing the correction amount close to an appropriate value.

  By increasing the correction amount step by step, even if the angle deviation is not eliminated by one subtraction and addition (that is, the correction amount is small and the angle deviation cannot be eliminated sufficiently), it is twice. The angle deviation can be reliably reduced by the third processing. Therefore, if such a process is repeated, the angular deviation can be surely eliminated.

  In another aspect of the control apparatus for an internal combustion engine of the present invention, the angle deviation detection means includes an envelope determination means for determining an envelope of a maximum value or a minimum value of a pulse signal of the rotation angle detection means, and a previous measurement time And the envelope comparison means for calculating the difference by comparing the envelope of the current measurement and the envelope at the time of the current measurement, and the difference in the envelope is greater than a predetermined third threshold value, the angular deviation occurs. Second angle deviation determination means for determining that the

  According to this aspect, at the time of the angle deviation detecting operation by the angle deviation detecting means, the envelope determining means first determines the maximum value or the minimum value envelope of the pulse signal of the rotation angle detecting means. The “envelope” here is a curve drawn by connecting only the maximum value or the minimum value of the pulse signal. The determined envelope is temporarily stored in a storage means such as a memory for use in the comparison described later.

  When the envelope is determined, the envelope comparison means compares the envelope at the previous measurement with the envelope at the current measurement, and the difference (that is, the envelope at the previous measurement and the envelope at the current measurement). The deviation width from the line is calculated. Note that the envelope difference may be calculated as a phase difference or an amplitude difference.

  When the envelope difference is calculated, it is determined by the second angle deviation determination means whether or not the difference is larger than a predetermined third threshold. The “third threshold value” here is a value set to determine the angle deviation of the rotation angle detection means from the envelope difference, and the angle deviation occurs when the envelope difference is larger than the third threshold value. It is determined that

  According to a study by the inventors of the present application, it has been found that when an angular deviation occurs in the rotation angle detection means, the maximum value and the minimum value in the pulse signal of the rotation angle detection means change more or less. Therefore, by comparing the envelope connecting these maximum values and minimum values with that at the time of the previous measurement, it is possible to suitably detect changes in the maximum values and minimum values and determine whether or not an angular deviation has occurred.

In another aspect of the control apparatus for an internal combustion engine of the present invention, the angle deviation detecting means uses the detected rotation angle to calculate a required period required for the rotation angle to change by a predetermined angle. A calculating means, a required period comparing means for calculating a difference by comparing the required period at the previous measurement with the required period at the current measurement, and a difference between the required periods being greater than a predetermined fourth threshold And a third angle deviation determining means for determining that the angle deviation has occurred.

  According to this aspect, at the time of the angle deviation detection operation by the angle deviation detection means, first, the required period calculation means calculates the required period required for the rotation angle of the internal combustion engine to change by a predetermined angle. The “predetermined angle” here is set in advance as an appropriate value for calculating the required period. The calculated required period is temporarily stored in a storage means such as a memory for use in the comparison described later.

  When the required period is calculated, the required period comparison means compares the required period at the previous measurement and the required period at the current measurement with each other, and the difference (that is, the required period at the previous measurement and the required value at the current measurement). The deviation width from the period is calculated.

  When the difference between the required periods is calculated, it is determined by the third angle deviation determination means whether or not the difference is greater than a predetermined fourth threshold value. The “fourth threshold value” here is a value set to determine the angle deviation of the rotation angle detection means from the difference between the required periods, and an angle deviation occurs when the difference between the required periods is greater than the fourth threshold value. It is determined that

  According to the research conducted by the present inventor, it has been found that the required time required for the rotation angle to change by a predetermined angle changes at least partially when an angle shift occurs in the rotation angle detection means. Therefore, by comparing these required periods with those at the time of the previous measurement, it can be determined whether or not an angle deviation has occurred suitably.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a block diagram which shows the structure of the vehicle which concerns on embodiment. It is the block diagram which showed schematically the structure of the crank angle sensor which concerns on embodiment. It is an example of a crank angle sensor signal and a cam angle sensor signal. It is a flowchart which shows operation | movement of the control apparatus of the internal combustion engine which concerns on 1st Embodiment. It is a conceptual diagram which shows the dispersion | variation for every cylinder of engine estimated torque. It is a conceptual diagram which shows the dispersion | variation maximum value for every cylinder of engine estimation torque, and the dispersion | variation in the angular acceleration of MG1. 3 is a flowchart showing rotation angle correction control by the control apparatus for an internal combustion engine according to the first embodiment. It is a flowchart which shows operation | movement of the control apparatus of the internal combustion engine which concerns on 2nd Embodiment. It is a graph which shows an envelope of a crank angle sensor signal and its maximum value. It is a graph which shows the fluctuation | variation of the envelope accompanying removal of a crank angle sensor. It is a flowchart which shows operation | movement of the control apparatus of the internal combustion engine which concerns on 3rd Embodiment. It is a graph which shows the fluctuation | variation of the angle change required period accompanying removal of a crank angle sensor.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a control device for an internal combustion engine of the present invention will be described based on the drawings.

<Vehicle configuration>
First, a vehicle 1 on which a control device 100 according to this embodiment is mounted will be described with reference to FIG. FIG. 1 is a block diagram illustrating the configuration of the vehicle according to the embodiment. In FIG. 1, for convenience of explanation, detailed components of the vehicle are omitted as appropriate, and only directly related components are shown.

  In FIG. 1, a vehicle 1 includes an engine 10, a first motor / generator (MG1) 11, a second motor / generator (MG2) 12, a power distribution mechanism 13 having a planetary gear mechanism, and a torsional damper 14. ing. The engine 10 is an example of an “internal combustion engine” according to the present invention, and the first motor / generator 11 is an example of an “electric motor” according to the present invention.

  Incidentally, the engine 10 according to the present embodiment is a four-cylinder engine having four cylinders as shown in the figure. However, the engine 10 is not limited to the four-cylinder engine. Various engines may be used.

  The crankshaft 101 of the engine 10 is connected via an torsional damper 14 to an input shaft 131 as a rotation shaft of a carrier 134 that supports a plurality of pinion gears 133 of the power distribution mechanism 13 so as to be capable of rotating and revolving. The engine 10 is provided with a crank angle sensor 31 that detects the crank angle of the engine 10 and a cam angle sensor 32 that detects the cam angle of the engine 10. The crank angle sensor 31 is an example of the “rotation angle detecting means” according to the present invention.

  Here, a specific configuration of the crank angle sensor 31 will be described with reference to FIGS. 2 and 3. FIG. 2 is a configuration diagram schematically showing the configuration of the crank angle sensor according to the embodiment, and FIG. 3 is an example of a crank angle sensor signal.

  In FIG. 2, a crank rotor 102 that is rotated in the direction of the arrow in the drawing is attached to the crankshaft 101. On the outer periphery of the crank rotor 102, for detecting the crank angle, for example, a tooth portion 102a formed at equal angular intervals of every 10 degrees CA and a missing tooth portion 102b continuously missing for two teeth are provided. ing.

  The crank angle sensor 31 is opposed to each tooth portion 102a, and includes a sensor portion 311 that detects the rotation angle of the crankshaft 101 by the tooth portion 102a, and a signal processing portion 312 that processes an output signal from the sensor portion 311. It is prepared for. The crank angle sensor signal output from the sensor unit 311 is a pulse signal with a period of rotation of a predetermined crank angle (for example, 10 degrees CA) as one cycle when the rotation position of the crankshaft 101 is not a predetermined specific position. When the crankshaft 101 comes to a specific position, it becomes a missing tooth signal with the period during which the crankshaft 101 rotates, for example, 30 degrees CA as one cycle. The missing tooth signal is generated every time the crankshaft 101 rotates once (that is, every 360 degrees CA).

  When the signal processing unit 312 receives the output signal from the sensor unit 311 (see the crank angle sensor signal in FIG. 3), the signal processing unit 312 starts the detection operation of the missing tooth signal in the crank angle sensor signal. Then, when the signal processing unit 312 first detects that the crank angle sensor signal is a missing tooth signal, thereafter, the signal processing unit 312 divides the crank angle sensor signal and sets the period during which the crankshaft 101 rotates 30 degrees as one cycle. A 30-degree CA signal NE (see FIG. 1) is generated and output as a pulse signal (that rises every time the crankshaft 101 rotates 30 degrees).

  Further, the signal processing unit 312 outputs the cam angle sensor 32 according to the rotation of the cam shaft of the engine 10 during the determination period corresponding to a predetermined period of the 30-degree CA signal NE after detecting the missing tooth signal. When the rising edge of the cylinder discrimination signal (see the cam sensor signal in FIG. 3) is detected, the reference position signal G is output at the end timing of the judgment period. Accordingly, the reference position signal G rises when the rotational position of the crankshaft 101 reaches a position advanced by a predetermined period from a specific position where a missing tooth signal is generated. The ENG-ECU 22 determines the cylinder of the engine 10 based on the 30-degree CA signal NE, the reference position signal G, and the like, and controls the engine 10.

  Note that the reference position signal G according to the present embodiment is a pulse signal (that is, a 720 degree CA signal) having a period during which the camshaft rotates 720 degrees.

  Returning to FIG. 1 again, the rotating shaft of the sun gear 132 of the power distribution mechanism 13 is connected to the first motor / generator 11. The rotating shaft of the ring gear 135 of the power distribution mechanism 13 is connected to the second motor / generator 12. The power output gear 136 of the power distribution mechanism 13 transmits power to a power transmission gear (not shown) via the chain belt 137. The power transmitted to the power transmission gear is transmitted to drive wheels (not shown) of the vehicle 1 via a drive shaft and a differential gear (not shown).

  The first motor / generator 11 is provided with a resolver 33 that detects the rotational speed of the first motor / generator 11. The second motor / generator 12 is provided with a resolver 34 that detects the rotational speed of the second motor / generator 12.

  The vehicle 1 further includes an engine ECU (Electronic Control Unit) 22 (hereinafter referred to as “ENG-ECU” as appropriate) that performs overall control of the engine 10, and a motor generator that performs various controls related to the first and second motor generators. An ECU (hereinafter referred to as “MG-ECU” as appropriate) 23 and a hybrid ECU 21 (hereinafter referred to as “HV-ECU” as appropriate) for performing various controls related to ENG-ECU 22 and MG-ECU 23 are provided.

  In the present embodiment, the synchronization of the ENG-ECU 22 and the MG-ECU 23 is ensured by inputting the 30 degree CA signal NE or the like output from the crank angle sensor 31 to the ENG-ECU 22 and the MG-ECU 23. .

  In the vehicle 1 configured as described above, for example, due to a change in clearance due to temporary removal of the crank angle sensor 31 or torsion of the crankshaft 101, the rotation angle value detected by the crank angle sensor 31 is shifted. Will occur. According to the control apparatus for an internal combustion engine according to the present embodiment, even when such an angular deviation occurs in the crank angle sensor 31, the control of the engine 10 can be suitably executed.

<Operation of control device>
Below, three embodiment is mentioned and demonstrated about operation | movement and a technical effect of the control apparatus of the internal combustion engine which concerns on this embodiment.

<First Embodiment>
First, the operation of the control apparatus for an internal combustion engine according to the first embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing the operation of the control device for the internal combustion engine according to the first embodiment. FIG. 5 is a conceptual diagram showing the variation of the estimated engine torque for each cylinder. FIG. 6 is a conceptual diagram showing the variation of the estimated engine torque for each cylinder and the variation of the angular acceleration of MG1.

  In FIG. 4, when the control device for the internal combustion engine according to the present embodiment is operating, first, the rotation angle of the engine 10 is detected by the crank angle sensor 31 (step S101). In addition, although description here is abbreviate | omitted, the detected rotation angle of the engine 10 is used for various control etc. based on the determination of the combustion state (for example, misfire etc.) of the engine 10, and the determined combustion state.

  In the control device for an internal combustion engine according to this embodiment, the resolver 33 detects the rotational speed of the first motor / generator 11 and the angular acceleration of the first motor / generator 11 (step S102).

  When the rotation angle of the engine 10 and the angular acceleration of the first motor / generator 11 are detected, the torque of the engine 10 is estimated for each cylinder by the control device 100 (step S103). The torque of the engine 10 can be calculated using, for example, the following formula (1).

エンジン１０のトルクが気筒別に推定されると、推定トルクの気筒間でのばらつきの最大値が所定の第１閾値以上であるか否かが判定される（ステップＳ１０４）。なお、気筒間でのばらつきの最大値は、推定トルクが最大である気筒のトルク値と、推定トルクが最小である気筒のトルク値との差分として算出できる。

When the torque of the engine 10 is estimated for each cylinder, it is determined whether or not the maximum value of the variation in the estimated torque among the cylinders is equal to or greater than a predetermined first threshold value (step S104). Note that the maximum value of the variation among the cylinders can be calculated as a difference between the torque value of the cylinder having the maximum estimated torque and the torque value of the cylinder having the minimum estimated torque.

  In FIG. 5, for example, it is assumed that a torque as shown in the figure is estimated for each of the cylinders # 1 to # 4. In this case, the difference between the torque of the cylinder # 2 having the maximum estimated torque and the torque of the cylinder # 4 having the minimum estimated torque is the maximum value of the inter-cylinder variation.

  Here, in particular, when an angular deviation occurs in the rotation angle detected by the crank angle sensor 31, a deviation also occurs in the angular acceleration of the engine 10, and as a result, the variation width of the torque estimated using the angular acceleration of the engine 10 Also grows. Therefore, when the variation width of the estimated torque is larger than the first threshold value, the crank angle sensor 31 may have an angular deviation. However, since there is a possibility that the torque actually varies from cylinder to cylinder, it cannot be said that the angular deviation is surely generated only by the estimated torque.

  Returning to FIG. 4, when the maximum value of the estimated torque variation between cylinders is equal to or greater than the first threshold value (step S104: YES), the variation in angular acceleration of the first motor / generator 11 is equal to or smaller than the predetermined second threshold value. It is determined whether or not there is.

  Here, if the torque of the engine 10 actually varies greatly from cylinder to cylinder, the torque fluctuation is also transmitted to the first motor / generator 11, so that the angular acceleration of the first motor / generator 11 also varies greatly. Therefore, when the variation in the angular acceleration of the first motor / generator 11 is smaller than the second threshold value, it can be determined that the actual torque of the engine 10 does not vary. If the torque variation of the engine 10 is larger than the first threshold and the angular acceleration of the first motor / generator 11 is smaller than the second threshold, the torque of the engine 10 is not actually varied. It can be said that the estimated torque varies greatly. For this reason, it can be determined that the estimated torque variation is not actual torque variation but is caused by erroneous detection of the rotation angle (that is, an angular deviation has occurred).

  In FIG. 5, it is assumed that the estimated torque of the engine 10 varies. Note that the maximum variation in estimated torque of the engine 10 tends to increase as the rotational speed of the engine 10 increases. In such a case, the angular acceleration of the first motor / generator 11 varies depending on whether the torque of the engine 10 actually varies or when the torque does not actually vary (that is, when only the estimated torque varies). Clear differences occur. Specifically, when the torque of the engine 10 does not actually vary, the angular acceleration of the first motor / generator 11 changes at a very small value regardless of the rotational speed of the engine 10. On the other hand, when the torque of the engine 10 is actually varied, the angular acceleration of the first motor / generator 11 becomes a relatively large value regardless of the rotational speed of the engine 10. Therefore, the value between the angular acceleration of the first motor / generator 11 when the torque of the engine 10 is actually varied and the angular acceleration of the first motor / generator 11 when the torque is not actually varied is the second value. If it is set as the threshold value, it can be determined whether or not the torque of the engine 10 actually varies.

  In FIG. 4 again, as described above, when the angular acceleration of the first motor / generator 11 is equal to or smaller than the second threshold (step S105: YES), it is determined that an angular deviation has occurred in the crank angle sensor 31, At least one control is executed among the combustion state estimation prohibition control, the crank angle sensor learning value reset, and the engine control prohibition control using the estimated combustion state (step S106). If the maximum value of the estimated torque variation between cylinders is not equal to or greater than the first threshold (step S104: NO), or the angular acceleration of the first motor / generator 11 is not equal to or less than the second threshold (step S105: NO), It is determined that no angular deviation has occurred in the crank angle sensor 31, and the above-described controls are not executed.

  Incidentally, according to the combustion state estimation prohibition control, it is possible to prevent the combustion state of the engine 10 from being estimated to be incorrect due to the detection of an inaccurate rotation angle. In addition, if the learning value of the crank angle sensor is reset, it is possible to prevent the inaccurate rotation speed from being continuously detected. Furthermore, according to the prohibition control of the engine control using the estimated combustion state, it is possible to prevent inappropriate control based on the combustion state from being executed even when an erroneous combustion state is estimated.

  When the angle control described above is executed, correction control of the crank angle sensor 31 is subsequently executed (step S107). Hereinafter, this correction control will be described in detail with reference to FIG. FIG. 7 is a flowchart showing rotation angle correction control by the control apparatus for an internal combustion engine according to the first embodiment.

  In FIG. 7, when the correction control of the crank angle sensor 31 is started, first, a predetermined angle is determined from the rotation angle in the torque calculation period of the cylinder (for example, cylinder # 2 in FIG. 5) in which the estimated torque for each cylinder is maximized. The correction value k is subtracted (step S201). Further, a predetermined correction value k is added to the rotation angle in the torque calculation period of the cylinder (for example, cylinder # 4 in FIG. 5) in which the estimated torque for each cylinder is minimized (step S202).

  In particular, the reason that the estimated torque for each cylinder is estimated to be large is that the angular acceleration of the engine 10 is calculated to be large, and that the detected rotation angle of the engine 10 is shifted to the larger one. Show. On the other hand, the reason that the estimated torque for each cylinder is estimated to be small is that the angular acceleration of the engine 10 is calculated to be small, indicating that the detected rotation angle of the engine 10 is shifted to the smaller one.

  Therefore, as described above, if the correction amount k is subtracted from the rotation angle when the estimated torque is calculated to be the largest and the correction amount k is added to the rotation angle when the estimated torque is calculated to be the smallest, The variation range of the estimated torque between the cylinders becomes smaller. In other words, the angular deviation in the crank angle sensor 31 is reduced. Therefore, the value detected by the crank angle sensor 31 can be brought close to an accurate value.

  After correcting the rotation angle, the torque of the engine 10 is estimated again for each cylinder (step S203). Then, it is determined whether or not the estimated maximum variation in torque is equal to or greater than the first threshold value (step S204). Note that the maximum torque variation estimated in step S203 is somewhat reduced by the above-described correction, but when the correction is not sufficient (that is, when the correction value k is too small), the torque threshold is not less than the first threshold value. It can be.

  If the estimated maximum torque variation is equal to or greater than the first threshold again (step S204: YES), it is determined that the angle deviation of the crank angle sensor 31 has not been sufficiently corrected, and the correction value k is set to a predetermined value Δk. Are added (step S205). That is, the correction value k is increased by Δk. When the correction value k is changed, the process is started again from step S201. By repeating the process in this manner, the estimated maximum torque variation gradually decreases, and finally becomes less than the first threshold value. When the estimated maximum torque variation is less than the first threshold (step S204: NO), the correction control ends.

  Returning to FIG. 4, when the correction control of the crank angle sensor 31 is completed, the combustion state estimation prohibition control and the engine control prohibition control using the estimated combustion state, which were prohibited in step S106, are released (step S108). Thus, various controls of the engine 10 are resumed using the detected value of the crank angle sensor 31 after the correction control.

  As described above, according to the control apparatus for an internal combustion engine according to the present embodiment, the engine 10 can be suitably controlled even when an angular deviation occurs in the rotation angle detected by the crank angle sensor 31. Is possible. Particularly in the present embodiment, since the engine 10 can detect the rotational angle deviation in the firing state (in other words, the angle deviation is likely to occur due to the twist of the crankshaft or the like), the control of the internal combustion engine can be very suitably performed. Can be executed.

Second Embodiment
Next, an internal combustion engine control apparatus according to a second embodiment will be described with reference to FIGS. FIG. 8 is a flowchart showing the operation of the control device for the internal combustion engine according to the second embodiment. FIG. 9 is a graph showing the envelope of the crank angle sensor signal and its maximum value, and FIG. 10 is a graph showing the fluctuation of the envelope due to the removal of the crank angle sensor.

  Note that the second embodiment differs from the first embodiment described above only in some operations, and the other parts are substantially the same. For this reason, below, a different part from 1st Embodiment is demonstrated in detail, and description shall be abbreviate | omitted suitably about the overlapping part.

  In FIG. 8, the control device for the internal combustion engine according to the second embodiment is different from the one that operates even in the fired state as in the first embodiment described above, and the motoring state (that is, the engine burns). Not working). When the control device for an internal combustion engine according to the second embodiment is operating, it is first determined whether or not the rotation of the motoring is constant (step S301). Note that if the motoring is not at a constant rotation (step S301: NO), the learning process to be described later cannot be performed properly, and the subsequent steps are not performed.

  If it is determined that the motoring is at a constant rotation (step S301: YES), a new crank angle sensor signal (see FIG. 3) is acquired (step S302). Further, the crank angle sensor signal acquired at the previous measurement is read from the storage means such as a memory (step S303). The newly acquired crank angle sensor signal and the crank angle sensor signal at the previous measurement are compared with each other, and a difference is calculated (step S304). In this embodiment, in particular, the difference between the crank angle sensor signals is calculated using the maximum value or the minimum value envelope of the signal.

  In FIG. 9, it is assumed that a crank angle sensor signal as shown in the figure is acquired. In this case, an envelope connecting the maximum values of the crank angle sensor signal is represented by a thick solid line in the figure. The envelope has a shape that periodically undulates with the missing tooth portion 102b (see FIG. 2) of the crank rotor 102 as a boundary. In particular, according to a study by the inventors of the present application, it has been found that the shape of the envelope hardly changes unless an angular deviation occurs in the crank angle sensor 31. In other words, when an angle shift occurs in the crank angle sensor 31, the shape of the envelope changes.

  In FIG. 10, it is assumed that the envelope of the crank angle sensor signal newly acquired this time and the envelope of the crank angle sensor signal at the previous measurement have shapes as shown in the figure. In this case, it can be seen that there is a phase shift between the envelope at the current measurement and the envelope at the previous measurement. Therefore, the crank angle sensor 31 is removed between the previous measurement and the current measurement, and as a result, it can be determined that an angular deviation has occurred in the crank angle sensor 31.

  Note that the deviation of the envelope may occur not only as a phase difference but also as an amplitude difference. Further, here, the maximum value envelope of the crank angle sensor signal is described, but the minimum value envelope of the crank angle sensor signal may be used.

  Returning to FIG. 8, the occurrence of the angle deviation is specifically determined based on whether or not the difference between the envelopes is equal to or greater than a predetermined third threshold (step S305). Here, when the difference of the envelope is equal to or greater than the third threshold (step S305: YES), it is determined that an angular deviation has occurred, and the combustion state estimation prohibition control, the crank, and the like, as in the first embodiment. At least one control is executed among the angle sensor learning value reset and the engine control prohibition control using the estimated combustion state (step S306).

  When each control described above is executed, the relearning of the crank angle sensor 31 is executed (step S307). That is, an appropriate learning value is learned according to the current situation in which the angular deviation has occurred. In addition, about a learning method, since a well-known method can be utilized suitably, detailed description here is abbreviate | omitted.

  When the relearning of the crank angle sensor 31 is executed, the processing after step S304 is started again. That is, the difference of the envelope is calculated again in the state where the relearning is executed, and it is determined whether or not the difference is equal to or greater than the third threshold value. By repeating the process in this manner, the angular deviation of the crank angle sensor 31 is reliably eliminated.

  When the envelope difference is less than the third threshold value (step S305: NO), the combustion state estimation prohibition control and the engine control prohibition control using the estimated combustion state, which were prohibited in step S306, are released ( Step S308). Thus, various controls of the engine 10 are resumed using the detected value of the crank angle sensor 31 after learning.

  As described above, according to the control apparatus for an internal combustion engine according to the second embodiment, as in the first embodiment described above, there is a case where an angular deviation has occurred in the rotation angle detected by the crank angle sensor 31. However, the engine 10 can be suitably controlled. Particularly in the second embodiment, since the rotational angle deviation is detected when the engine 10 is in the motoring state, the rotational angle deviation can be corrected with high accuracy.

<Third Embodiment>
Next, an internal combustion engine control apparatus according to a third embodiment will be described with reference to FIGS. FIG. 11 is a flowchart showing the operation of the control device for the internal combustion engine according to the third embodiment. FIG. 12 is a graph showing fluctuations in the required period of angle change accompanying removal of the crank angle sensor.

  Note that the third embodiment differs from the first and second embodiments described above only in part of the operation, and the other parts are substantially the same. For this reason, below, a different part from 1st and 2nd embodiment is demonstrated in detail, and description shall be abbreviate | omitted suitably about the overlapping part.

  In FIG. 11, when the internal combustion engine control apparatus according to the second embodiment operates, it is first determined whether or not the rotation of the motoring is constant (step S401). If the motoring is not at a constant rotation (step S401: NO), the learning process described later cannot be performed properly, and the subsequent steps are not performed.

  If it is determined that the motoring has a constant rotation (step S401: YES), a period required to change the rotation angle by a predetermined angle (hereinafter simply referred to as “required period”) is newly calculated (step S402). Further, the required period at the previous measurement is read from the storage means such as a memory (step S403). The newly calculated required period and the required period at the previous measurement are compared with each other, and a difference is calculated (step S404).

  In FIG. 12, it is assumed that the newly calculated 30 degree CA required period this time and the 30 degree CA required period at the time of the previous measurement have shapes as shown in the figure. The required period for the current measurement and the required period for the previous measurement are almost the same, but there is a slight deviation in the area surrounded by the broken line in the figure. As a result of research by the inventors of the present application, it has been found that the required period hardly changes unless an angular deviation occurs in the crank angle sensor 31. Therefore, in the situation shown in the figure, the crank angle sensor 31 is detached between the previous measurement and the current measurement, and as a result, it can be determined that the crank angle sensor 31 has an angular deviation.

  Returning to FIG. 11, the occurrence of the angle deviation is specifically determined based on whether or not the difference between the required periods (that is, the deviation width in FIG. 12) is equal to or greater than a predetermined fourth threshold value (step S <b> 405). Here, when the difference between the required periods is equal to or greater than the fourth threshold value (step S405: YES), it is determined that an angular deviation has occurred, and the combustion state estimation is prohibited as in the first and second embodiments. At least one of control, crank angle sensor learning value reset, and engine control prohibition control using the estimated combustion state is executed (step S406).

  When each control described above is executed, relearning of the crank angle sensor 31 is executed (step S407). That is, an appropriate learning value is learned according to the current situation in which the angular deviation has occurred. When the relearning of the crank angle sensor 31 is executed, the processing after step S404 is started again. That is, the difference of the required period is calculated again in the state where the relearning is executed, and it is determined whether or not the difference is equal to or greater than the fourth threshold value. By repeating the process in this manner, the angular deviation of the crank angle sensor 31 is reliably eliminated.

  When the difference between the required periods becomes less than the fourth threshold value (step S405: NO), the combustion state estimation prohibition control and the engine control prohibition control using the estimated combustion state, which were prohibited in step S406, are canceled ( Step S408). Thus, various controls of the engine 10 are resumed using the detected value of the crank angle sensor 31 after learning.

  As described above, according to the control apparatus for an internal combustion engine according to the third embodiment, an angular deviation occurs in the rotation angle detected by the crank angle sensor 31 as in the first and second embodiments described above. Even in this case, the engine 10 can be suitably controlled. Particularly in the third embodiment, it is possible to correct the rotational angle deviation with high accuracy, in which the rotational angle deviation is detected when the engine 10 is in the motoring state.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The control device is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 10 ... Engine, 11 ... 1st motor generator, 12 ... 2nd motor generator, 13 ... Power distribution mechanism, 14 ... Torsional damper, 21 ... HV-ECU, 22 ... ENG-ECU, 23 ... MG-ECU, 31 ... crank angle sensor, 32 ... cam angle sensor, 33, 34 ... resolver, 100 ... control device, 101 ... crankshaft.

Claims (5)

It is mounted on a vehicle equipped with an internal combustion engine and an electric motor as a power source,
Rotation angle detection means for detecting the rotation angle of the internal combustion engine;
Combustion state estimation means for estimating a combustion state of the internal combustion engine based on the detected rotation angle;
An angular deviation detecting means for detecting that an angular deviation has occurred in the rotation angle detecting means;
When the angular deviation is detected, among the estimation prohibition control of the combustion state of the internal combustion engine, the reset control of the learning value of the rotation angle detection means, and the prohibition control of the control using the estimated combustion state, Control execution means for executing at least one control ,
The angular deviation detecting means is
Torque estimating means for estimating the torque of a plurality of cylinders of the internal combustion engine for each cylinder using the angular acceleration of the internal combustion engine;
Electric motor angular acceleration detecting means for detecting angular acceleration of the electric motor;
When the torque variation width between the plurality of cylinders in the internal combustion engine is larger than a predetermined first threshold value and the variation width of the angular acceleration of the electric motor is smaller than a predetermined second threshold value, the angular deviation occurs. First angle deviation determining means for determining that
Control apparatus for an internal combustion engine, characterized in that it comprises a. When it is determined by the first angle shift determination means that the angle shift has occurred, a predetermined correction is made from the detected rotation angle when the torque of the cylinder having the largest torque among the plurality of cylinders is calculated. And a rotation angle correction unit that subtracts the amount and adds the predetermined correction amount to the detected rotation angle when the torque of the cylinder having the smallest torque among the plurality of cylinders is calculated. The control apparatus for an internal combustion engine according to claim 1 . When the rotation angle correction means determines that the angle deviation is generated by the first angle deviation determination means despite the subtraction and addition of the correction amount, the rotation angle correction means reduces the correction amount by a predetermined value. 3. The control apparatus for an internal combustion engine according to claim 2 , wherein the correction amount is subtracted and added again after being increased. The angular deviation detecting means is
An envelope determination means for determining an envelope of a maximum value or a minimum value of a pulse signal of the rotation angle detection means;
An envelope comparison means for comparing the envelope at the time of the previous measurement and the envelope at the time of the current measurement to calculate a difference;
2. The internal combustion engine according to claim 1, further comprising: a second angular deviation determination unit that determines that the angular deviation has occurred when the difference between the envelopes is larger than a predetermined third threshold value. Control device. The angular deviation detecting means is
Using the detected rotation angle, a required period calculating means for calculating a required period required for the rotation angle to change by a predetermined angle;
A required period comparing means for calculating a difference by comparing the required period at the previous measurement and the required period at the current measurement;
2. The internal combustion engine according to claim 1, further comprising third angle deviation determination means that determines that the angular deviation has occurred when the difference between the required periods is greater than a predetermined fourth threshold value. Control device.

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