JP2019031959A - Ignition timing control device of internal combustion engine - Google Patents

Abstract

To provide an ignition timing control device of an internal combustion engine capable of suppressing occurrence of a situation that an ignition timing is excessively retarded on the basis of inappropriate update of a knock learning value.SOLUTION: A control device 50 as an ignition timing control device of an internal combustion engine includes a base ignition timing calculation portion 53, a knock determination portion 54, a correction portion 55 for calculating a feedback correction value ekcs for correcting the base ignition timing ebse to a retard side, a learning portion 56 for updating the knock learning value eknk based on the feedback correction value ekcs in a learning region determined according to an operation state of the internal combustion engine, and a required ignition timing setting portion 57 for setting a required ignition timing efin on the basis of the base ignition timing ebse, the feedback correction value ekcs and the knock learning value eknk. The learning portion 56 does not update the knock learning value eknk when a vehicle in which the internal combustion engine is mounted, is stopped when the operation state of the internal combustion engine is in the learning region.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an ignition timing control device for an internal combustion engine.

  The ignition timing control device for an internal combustion engine described in Patent Document 1 determines the occurrence of knocking in the internal combustion engine based on an output signal from a knock sensor provided in the internal combustion engine. When it is determined that knocking has occurred, a feedback correction value for correcting the base ignition timing to the retard side is calculated. The feedback correction value is a control amount used for immediately changing the ignition timing to the retard side when knocking occurs. The ignition timing control device for an internal combustion engine described in Patent Document 1 updates the knock learning value based on the feedback correction value. The knock learning value is a control amount for suppressing knocking that occurs due to a change with time of the internal combustion engine. The ignition timing control device for an internal combustion engine suppresses the occurrence of knocking by calculating the required ignition timing based on the base ignition timing, the feedback correction value, and the knock learning value. The ignition timing control device for an internal combustion engine described in Patent Document 1 updates the knock learning value when the operation region of the internal combustion engine is in a knock control region that is a predetermined engine load region.

JP-A-8-42434

  The knock sensor detects vibrations of the internal combustion engine, and the output signal also reflects vibrations caused by factors other than knocking. In particular, when the vehicle is stopped and in an idle operation state, the combustion interval is longer than that in the normal operation state when the vehicle is running, so vibrations caused by other factors other than knocking such as vibrations caused by rotational fluctuations. Is likely to occur. When determining the occurrence of knocking based on the output signal from the knock sensor, it is erroneously determined that knocking has occurred despite the fact that knocking has not actually occurred due to vibration caused by other factors. May end up. In this case, even if the ignition timing is retarded, the output signal of the knock sensor is unlikely to change, and the ignition timing may continue to be retarded. If the knock learning value is updated in this state, the knock learning value is updated to a greatly retarded value. For this reason, when shifting from idle operation to normal operation, the ignition timing is excessively retarded and the output torque of the internal combustion engine is less likely to increase.

  The ignition timing control device for an internal combustion engine described in Patent Document 1 does not update the knock learning value when the operation region of the internal combustion engine is not the knock control region during idle operation. Therefore, the problem described above is unlikely to occur when the engine load is lower than the knock control range.

  By the way, for example, in a hybrid vehicle including an internal combustion engine and a motor as drive sources, the internal combustion engine may be driven to charge a battery when the vehicle is stopped. When charging the battery, the internal combustion engine is connected to a generator. Then, the generator is rotated by the driving force of the internal combustion engine to generate power. In such an operating state, the load on the internal combustion engine increases, and therefore the operating region of the internal combustion engine may be the knocking control region even during idle operation where vibration due to factors other than knocking is likely to occur. In such a case, when the ignition timing control described in Patent Document 1 is performed, the above-described problem may occur. In the ignition timing control device for an internal combustion engine described in Patent Document 1, this point is not considered and there is room for improvement.

  An ignition timing control device for an internal combustion engine for solving the above-described problem includes a base ignition timing calculation unit that calculates a base ignition timing, and whether or not knocking has occurred in the internal combustion engine based on an output signal from a knock sensor. A knock determination unit for determining, a correction unit for calculating a feedback correction value for correcting the base ignition timing to the retard side based on the occurrence of knocking by the knock determination unit, and an operating state of the internal combustion engine A learning unit that updates a knock learning value based on the feedback correction value when in a learning region set in accordance with, and a required ignition based on the base ignition timing, the feedback correction value, and the knock learning value A required ignition timing setting unit for setting a timing, and the learning unit is configured to perform the operation when the operating state of the internal combustion engine is in the learning region. When a vehicle combustion engine is mounted is parked does not update the knock learned value.

  In the above configuration, even when the operation state of the internal combustion engine is in the learning region where the knock learning value is updated, the knock learning value is not updated when the vehicle is stopped and in the idle operation state. Therefore, the update of the knock learning value can be prohibited in a state in which vibration due to other factors other than knocking is likely to occur. Thereby, the update to the retard side of the knock learning value due to erroneous determination of the occurrence of knocking is suppressed. Therefore, according to the above configuration, it is possible to suppress the occurrence of a situation in which the ignition timing is excessively retarded based on an inappropriate update of the knock learning value when the vehicle state shifts from stop to travel. be able to.

The schematic diagram which shows the structure of the vehicle by which the ignition timing control apparatus of an internal combustion engine is mounted. The schematic diagram which shows the setting aspect of the request | requirement ignition timing which concerns on knock control. The functional block diagram of the ignition timing control apparatus of an internal combustion engine. The map which shows a knock control prohibition area | region and a knock control execution area | region. The flowchart which shows the flow of a series of processes concerning knock control.

An embodiment of an ignition timing control device for an internal combustion engine will be described with reference to FIGS.
As shown in FIG. 1, a vehicle 100 on which an ignition timing control device for an internal combustion engine is mounted includes an internal combustion engine 10 and a motor 20 as power sources. The internal combustion engine 10 has an engine body 11 in which a plurality of combustion chambers 11A are formed. The engine body 11 is provided with a fuel injection valve 12 for each combustion chamber 11A. The fuel injection valve 12 injects fuel into the combustion chamber 11A. The engine body 11 is provided with a spark plug 13 for each combustion chamber 11A. An intake passage 14 is connected to the engine body 11. The intake air flowing through the intake passage 14 is supplied to each combustion chamber 11A. In the combustion chamber 11A, the intake air supplied from the intake passage 14 and the fuel injected from the fuel injection valve 12 are mixed to generate an air-fuel mixture. When the air-fuel mixture is ignited by the spark plug 13, it combusts and exhaust is generated.

  An exhaust passage 15 is connected to the engine body 11. Exhaust gas is discharged from each combustion chamber 11 </ b> A into the exhaust passage 15. A catalyst 16 for purifying exhaust gas is provided in the exhaust passage 15. Exhaust gas discharged to the exhaust passage 15 is purified when passing through the catalyst 16 and is released to the outside of the vehicle 100. A knock sensor 30 and a water temperature sensor 31 are attached to the engine body 11. Knock sensor 30 outputs an electrical signal corresponding to the vibration of engine body 11. The water temperature sensor 31 outputs an electrical signal corresponding to the coolant temperature of the engine body 11.

  The crankshaft 11 </ b> B of the engine body 11 is connected to the power split mechanism 40. A drive shaft 20 </ b> A of the motor 20 is also connected to the power split mechanism 40. The motor 20 is connected to a battery 45 and is driven to rotate when electric power is supplied from the battery 45. A reduction gear 46 is connected to the power split mechanism 40. An output shaft 47 connected to a wheel 48 is connected to the speed reducer 46. The power split mechanism 40 transmits the driving force of the internal combustion engine 10 and the driving force of the motor 20 to the output shaft 47 via the speed reducer 46. Thereby, the wheel 48 rotates and the vehicle 100 travels. The power split mechanism 40 is configured to be able to transmit the rotational force of the crankshaft 11B of the internal combustion engine 10 to the drive shaft 20A of the motor 20. Thereby, the motor 20 is rotationally driven by the driving force of the internal combustion engine 10. The motor 20 also has a function as a generator that generates electric power by being rotationally driven by the driving force of the internal combustion engine 10. The electric power generated by the motor 20 is charged in the battery 45.

  The vehicle 100 is equipped with a control device 50 that performs various controls of the vehicle 100. Output signals from the knock sensor 30 and the water temperature sensor 31 are input to the control device 50. Further, the crank angle sensor 32 for detecting the rotation speed of the crankshaft 11B, that is, the engine rotation speed, the accelerator sensor 33 for detecting the accelerator operation amount, the shift sensor 34 for detecting the shift range of the vehicle 100, and the charge amount of the battery 45 are set. An output signal from the charge amount sensor 35 to be detected is input. The control device 50 performs charge control for charging the battery 45 by rotating the motor 20 with the driving force of the internal combustion engine 10 when a predetermined charging request is made. In the present embodiment, the control device 50 performs a predetermined operation when the charge amount of the battery 45 detected by the charge amount sensor 35 is equal to or less than a predetermined amount, and when the vehicle is stopped and the internal combustion engine 10 is in an idle operation state. It is determined that there is a charge request. Further, the control device 50 controls the ignition timing of the ignition plug 13 of the internal combustion engine 10 during the operation of the internal combustion engine 10 to execute knock control that suppresses the occurrence of knocking. The control device 50 functions as an ignition timing control device for the internal combustion engine.

An overview of knock control will be described with reference to FIG. Hereinafter, the ignition timing is indicated by a crank angle [° CA]. The ignition timing is expressed as an advance amount from the compression top dead center to the advance side.
As shown in FIG. 2, the required ignition timing efin is set based on the base ignition timing ebse, the feedback correction value ekcs, and the knock learning value eknk.

  The base ignition timing ebse is set to the same value as the more retarded value of the MBT point ambt and the advance side knock limit point aknok1. The MBT point ambt is an ignition timing at which the maximum torque can be obtained under the current engine operating conditions. The advance angle side knock limit point aknok1 is the ignition timing on the most advanced angle side in a range where knocking does not occur when changes with time of the internal combustion engine 10 are not taken into consideration. The MBT point ambt and the advance side knock limit point aknok1 are calculated with reference to the setting map stored in the memory of the control device 50 based on the current engine speed, engine load, and the like. The engine load can be calculated based on the engine rotation speed and the accelerator operation amount.

  The feedback correction value ekcs is set based on a determination result of whether knocking has occurred. The feedback correction value ekcs is gradually decreased to a small value when it is determined that knocking has not occurred, and is gradually increased when it is determined that knocking has occurred. Value.

  The knock learning value eknk is a value for compensating for a change in ignition timing caused by a change with time of the internal combustion engine 10 or the like. As a factor of the time-dependent change of the internal combustion engine 10, for example, deposit adhesion to the internal combustion engine 10 can be cited. Knock learning value eknk is derived based on feedback correction value ekcs.

  The required ignition timing efin is calculated as a timing that is corrected to the retard side by the feedback correction value ekcs and the knock learning value eknk with respect to the base ignition timing ebse. In the present embodiment, the feedback correction value ekcs is set to a positive value when the ignition timing is changed to the retard side, and is set to a negative value when the ignition timing is changed to the advance side. That is, when the required ignition timing efin is corrected by the feedback correction value ekcs, the required ignition timing efin is corrected to the retard side as the feedback correction value ekcs increases. The knock learning value eknk is set to a value equal to or greater than “0”. That is, when the required ignition timing efin is corrected by the knock learning value eknk, the required ignition timing efin is corrected to the retard side as the knock learning value eknk is larger.

  The retard side knock limit point aknok2 is the most retarded ignition timing within a range in which knocking does not occur when the temporal change of the internal combustion engine 10 is not taken into consideration. The retard side knock limit point aknok2 is set in consideration of the current engine speed, engine load factor, and the like. A specified time eakmf1 is set on the advance side of the retard side knock limit point aknok2. A region between the specified time eakmf1 and the retard side knock limit point aknok2 is an acceleration failure region R1. When the ignition timing is included in the acceleration failure region R1, the acceleration performance of the vehicle 100 may be significantly deteriorated.

  In the present embodiment, control is performed such that the sum of the feedback correction value ekcs and the knock learning value eknk does not exceed the maximum retard amount ekmax, which is the difference between the base ignition timing ebse and the retard side knock limit point aknok2.

  As shown in FIG. 3, the control device 50 includes an operation region determination unit 51, a shift determination unit 52, a base ignition timing calculation unit 53, a knock determination unit 54, a correction unit 55, as functional units for executing knock control. A learning unit 56, a required ignition timing setting unit 57, and an ignition control unit 58 are provided.

  The operation region determination unit 51 determines the current operation region based on the current engine speed and engine load. As shown in FIG. 4, the operation region includes a knock control prohibition region R2 and a knock control execution region R3. The knock control prohibition region R2 includes an idle operation region when the charge control is not being executed when the vehicle 100 is stopped. The knock control execution region R3 is set to a region where the engine speed and the engine load are increased compared to the knock control prohibition region R2, and the charge control is executed when the vehicle 100 is stopped. The idle operation area is included.

  As shown in FIG. 3, the shift determination unit 52 determines whether or not the current shift range of the vehicle 100 is a parking position (hereinafter referred to as “P position”) based on an output signal from the shift sensor 34. To do.

  The base ignition timing calculation unit 53 calculates the MBT point ambt and the advance side knock limit point aknok1 based on the current engine speed and engine load. The base ignition timing calculation unit 53 calculates the same value as the more retarded value of the MBT point ambt and the advance side knock limit point aknok1 as the base ignition timing ebse.

Knock determination unit 54 determines whether or not knocking has occurred in internal combustion engine 10 based on the output signal from knock sensor 30.
The correction unit 55 calculates a feedback correction value ekcs for correcting the base ignition timing to the retard side based on the knock determination unit 54 determining the occurrence of knocking.

  The learning unit 56 calculates a knock learning value eknk based on the feedback correction value ekcs calculated by the correction unit 55 when the driving region determined by the driving region determination unit 51 is in the knock control execution region R3. Then, the learning unit 56 updates the knock learning value eknk when the learning value update condition is satisfied. The updated knock learning value eknk is stored in the learning unit 56. The learning value update condition is detected by the water temperature sensor 31 that the operation state of the internal combustion engine 10 is in the knock control execution region R3, the shift range determined by the shift determination unit 52 is not the P position, and the water temperature sensor 31. It is included that the cooling water temperature is equal to or higher than a predetermined temperature. Thus, the learning unit 56 updates the knock learning value eknk when it is in the knock control execution region R3 set according to the operating state of the internal combustion engine 10. In the present embodiment, the knock control execution region R3 corresponds to the learning region.

  The required ignition timing setting unit 57 is based on the base ignition timing ebse set by the base ignition timing calculation unit 53, the feedback correction value ekcs calculated by the correction unit 55, and the knock learning value eknk calculated by the learning unit 56. Then, the required ignition timing efin is set.

The ignition control unit 58 controls the spark plug 13 so that ignition is performed at the required ignition timing efin set by the required ignition timing setting unit 57.
With reference to the flowchart of FIG. 5, a flow of a series of processes related to knock control executed by the control device 50 will be described. This series of processes is executed by the control device 50 every predetermined end.

  As shown in FIG. 5, when the control device 50 starts this series of processing, first, the operation region determination unit 51 determines whether or not the current operation region of the internal combustion engine 10 is in the knock control execution region R3. (Step S500). When operation region determination unit 51 determines that the current operation region of internal combustion engine 10 is in knock control execution region R3 (step S500: YES), control device 50 starts knock control.

  In the present embodiment, in the vehicle 100 including the internal combustion engine 10 and the motor 20 as drive sources, when the remaining charge amount is small and the vehicle 100 is stopped, the charging control is performed assuming that the charging request is made. In this case, even in the idling operation region where the vehicle 100 is stopped, the engine speed and the engine load are high, and the current operation region of the internal combustion engine 10 is changed from the knock control prohibition region R2 to the knock control execution region R3. Will change. In the charging control, the crankshaft 11B of the internal combustion engine 10 is connected to the drive shaft 20A of the motor 20 to rotationally drive the motor 20. For this reason, the internal combustion engine 10 is in a state in which vibration is likely to be generated, for example, by receiving an impact when rotating the motor 20 from a stopped state or a rotational fluctuation of the motor 20. That is, during the execution of the charge control, the internal combustion engine 10 is in an operating state in which vibrations due to factors other than knocking are likely to occur. Therefore, in the present embodiment, the ignition timing is controlled as follows in the knock control.

  When control device 50 starts knock control, knock determination unit 54 determines whether knock has occurred in internal combustion engine 10 (step S501). In this process, for example, it is determined that knocking has occurred when the output signal of the knock sensor 30 indicates a predetermined vibration mode. If knock determination unit 54 determines that knocking has occurred (step S501: YES), then correction unit 55 calculates feedback correction value ekcs (step S502). In the process of step S502, since the occurrence of knocking is determined, the correction unit 55 calculates the feedback correction value ekcs by increasing it.

  In the process of step S501, if the knock determination unit 54 determines that knocking has not occurred (step S501: NO), then the correction unit 55 calculates a feedback correction value ekcs (step S503). In step S503, since the occurrence of knocking is not determined, the correction unit 55 calculates the feedback correction value ekcs by decreasing it.

  Thereafter, the learning unit 56 calculates a knock learning value eknk based on the feedback correction value ekcs calculated by the correction unit 55 (step S504). In this process, for example, a smoothed value obtained by smoothing the knock learning value eknk and the feedback correction value ekcs stored in the learning unit 56 is calculated as a new knock learning value eknk. As a smoothing method, a method of calculating a weighted average in which the weighting for the knock learning value eknk stored in the learning unit 56 is larger than the weighting for the feedback correction value ekcs can be employed.

  Next, the learning unit 56 determines whether or not a learning value update condition is satisfied (step S505). The learning value update condition is that the operating state of the internal combustion engine 10 is in the knock control execution region R3, that the shift range determined by the shift determination unit 52 is not the P position, and the cooling water temperature detected by the water temperature sensor 31. Is above a predetermined temperature. Therefore, in this process, the learning unit 56 makes an affirmative determination when the shift range is not the P position and the vehicle is in a traveling state (step S505: YES), and proceeds to the process of step S506. In the process of step S506, the learning unit 56 updates the knock learning value eknk calculated in the process of step S504 as a new learning value (step S506). Then, the updated knock learning value eknk is stored.

  Thereafter, the base ignition timing calculation unit 53 calculates the base ignition timing (step S507). Then, the required ignition timing setting unit 57 calculates the required ignition timing efin based on the calculated base ignition timing and feedback correction value ekcs and the knock learning value eknk stored in the learning unit 56 (step S508). ).

  When the required ignition timing is set in this way, the ignition control unit 58 controls the spark plug 13 so that ignition is performed at the required ignition timing efin, and executes ignition control (step S509). Thereafter, the control device 50 ends a series of processes related to knock control.

  On the other hand, when the shift range is in the P position, that is, when it can be determined that the vehicle 100 is stopped, the learning unit 56 determines in step S505 that the learning value update condition is not satisfied (step S505). : NO). In this case, the control device 50 proceeds to the process of step S507 without executing the process of step S506 by the learning unit 56. That is, the learning unit 56 does not update the knock learning value eknk calculated in the process of step S503. Therefore, by performing the processing of the subsequent steps S507 to S509, without causing a change in the knock learning value eknk stored in the learning unit 56 before executing a series of processing related to the knock control, The ignition timing in the knock control is controlled based on the stored knock learning value eknk.

  Further, in the process of step S500, when the operation region determination unit 51 determines that the current operation region of the internal combustion engine 10 is in the knock control prohibition region R2 (step S500: NO), the following processing is executed. Instead, a series of processes related to the knock control is terminated.

The effect of this embodiment is demonstrated.
(1) In the present embodiment, even when the operation state of the internal combustion engine 10 is in the knock control execution region R3 in which the knock learning value eknk is updated, when the vehicle 100 stops and is in the idle operation state, The knock learning value eknk is not updated. Therefore, the update of the knock learning value eknk can be prohibited in a state in which vibration due to factors other than knocking is likely to occur. As a result, the update of the knock learning value eknk to the retard side due to erroneous determination of the occurrence of knocking is suppressed. Therefore, according to the above configuration, when the state of the vehicle 100 shifts from the stop state to the travel state, a situation in which the ignition timing is excessively retarded based on the inappropriate update of the knock learning value eknk occurs. Can be suppressed.

The above embodiment can be implemented with the following modifications. The following modifications can be implemented in combination with each other as appropriate.
In the above embodiment, as the learning value update condition in the learning unit 56, the operating state of the internal combustion engine 10 is in the knock control execution region R3, the shift range determined by the shift determination unit 52 is not the P position, and It included that the cooling water temperature detected by the water temperature sensor 31 was equal to or higher than a predetermined temperature. The learning value update condition is not limited to this. For example, the determination based on the cooling water temperature may be omitted. In addition, the fact that the shift range is not the P position is a condition provided for determining that the vehicle 100 is stopped. Therefore, instead of or in addition to the condition that the shift range is not the P position, a condition for determining that the vehicle 100 is stopped may be employed. An example of such a condition is that the vehicle speed is “0”.

  The learning unit 56 may calculate the knock learning value eknk when the learning value update condition is satisfied. In this case, after a positive determination is made in the process of step S505, the process of step S504 may be executed.

  In the above embodiment, in the knock control, when the occurrence of knocking is not determined (step S501: NO), the feedback correction value ekcs is decreased. However, such a configuration is not necessarily provided. For example, when the occurrence of knocking is not determined, the feedback correction value ekcs may be set to “0”. Even in this case, the correction unit 55 can correct the base ignition timing ebse to the retard side by increasing the feedback correction value ekcs when the knock determination unit 54 determines the occurrence of knocking.

  In the knock control, the operation region of the internal combustion engine 10 is configured to include the knock control prohibition region R2 and the knock control execution region R3, and the knock control is performed when the operation region of the internal combustion engine 10 is in the knock control execution region R3. Executed. Instead of such a configuration, knock control may be executed regardless of the operating region of the internal combustion engine 10. Even in such a case, the learning region may be set according to the operating state of the internal combustion engine 10, and the knock learning value eknk may be updated when the operating region of the internal combustion engine 10 is in the set learning region. For example, when the vehicle 100 is stopped, the learning region is set so that the learning region does not include the idle operation region when the charge control is not performed and includes the idle operation region when the charge control is performed. can do. In this configuration, the knock learning value eknk may not be updated while the knock control is performed in the idle operation region when the charge control is not performed. In this configuration, even when the operating state of the internal combustion engine 10 is in the learning region, the knock learning value eknk is not updated when the vehicle 100 is stopped.

  In the above embodiment, the example in which the ignition timing control device for the internal combustion engine is applied to the vehicle 100 including the internal combustion engine 10 and the motor 20 as drive sources has been described. Not limited to. For example, the same configuration can be applied even to a vehicle including only the internal combustion engine 10 as a drive source. In this case, when the vehicle is in the idling operation region where the vehicle is stopped, the load on the internal combustion engine 10 is increased, for example, when the auxiliary machine is rotationally driven by the internal combustion engine 10. There are cases where the knock control prohibition region R2 changes to the knock control execution region R3. Also in this case, the internal combustion engine 10 is likely to be vibrated due to, for example, transmission of an impact when rotating the auxiliary machine from a stopped state or a rotational fluctuation of the auxiliary machine. Therefore, by applying a configuration similar to that of the above-described ignition timing control device for an internal combustion engine, it is possible to obtain the same operational effect as in the above (1).

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Engine main body, 11A ... Combustion chamber, 11B ... Crankshaft, 12 ... Fuel injection valve, 13 ... Spark plug, 14 ... Intake passage, 15 ... Exhaust passage, 16 ... Catalyst, 20 ... Motor, 20A DESCRIPTION OF SYMBOLS ... Drive shaft, 30 ... Knock sensor, 31 ... Water temperature sensor, 32 ... Crank angle sensor, 33 ... Accelerator sensor, 34 ... Shift sensor, 35 ... Charge amount sensor, 40 ... Power split mechanism, 45 ... Battery, 46 ... Reduction gear , 47 ... output shaft, 48 ... wheels, 50 ... control device, 51 ... driving region determination unit, 52 ... shift determination unit, 53 ... base ignition timing calculation unit, 54 ... knock determination unit, 55 ... correction unit, 56 ... learning , 57 ... Required ignition timing setting unit, 58 ... Ignition control unit, 100 ... Vehicle.

Claims (1)

A base ignition timing calculation unit for calculating a base ignition timing;
A knock determination unit for determining whether knocking has occurred in the internal combustion engine based on an output signal from the knock sensor;
A correction unit that calculates a feedback correction value for correcting the base ignition timing to the retard side based on the determination of the occurrence of knocking by the knock determination unit;
A learning unit that updates a knock learning value based on the feedback correction value when in a learning region set according to an operating state of the internal combustion engine;
A required ignition timing setting unit that sets a required ignition timing based on the base ignition timing, the feedback correction value, and the knock learning value;
The learning unit does not update the knock learning value when the vehicle on which the internal combustion engine is mounted is stopped when the operating state of the internal combustion engine is in the learning region. apparatus.