JP4082244B2 - Control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for an internal combustion engine.
[0002]
[Prior art]
In recent years, an internal combustion engine mounted on a vehicle is provided with a variable valve system that can change valve opening / closing operation conditions such as the lift amount and opening / closing timing of an intake valve or an exhaust valve, depending on the accelerator opening, engine speed, etc. In some cases, the valve opening / closing operation conditions are variably controlled. Specifically, for example, a low speed cam having a relatively small cam lift amount and a high speed cam having a relatively large cam lift amount are provided on the cam shaft, and the intake valve or the high speed cam is selectively used. Open and close the exhaust valve. In this case, the operating range of the low-speed cam and the operating range of the high-speed cam are set in advance for the engine operating range, and the corresponding cam is appropriately switched according to the accelerator opening and the engine speed. It was supposed to be used.
[0003]
In Patent Document 1 (Japanese Patent No. 2827768), there is a configuration in which the fuel consumption valve operation mode and the output valve operation mode are switched according to the operation region, and switching from the output valve operation mode to the fuel consumption valve operation mode is switched. After that, when the throttle opening that generates the same output torque is reached, the reverse switching from the fuel consumption valve operation mode to the output valve operation mode is accompanied by a torque down correction including a decrease in the throttle opening. I am trying to do it. Thereby, the suppression effect of the torque level difference at the time of switching of the valve operation mode is obtained.
[0004]
[Patent Document 1]
Japanese Patent No. 2827768 [0005]
[Problems to be solved by the invention]
However, in various configurations of the variable valve system and the intake system, the charging efficiency and the like greatly change due to machine difference variations and changes with time. In the technique of the above-mentioned patent document 1, since the influence due to the machine difference variation and the change with the passage of time is not taken into consideration, an unexpected control error occurs, and a desired effect cannot be obtained. That is, unexpected torque steps and air-fuel ratio fluctuations occur, and there is a concern that drivability and exhaust emissions will deteriorate.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to suitably switch the state of an operating state variable system such as a variable valve system, and thus to keep the operating state of the internal combustion engine well. It is an object to provide a control device for an internal combustion engine.
[0007]
[Means for Solving the Problems]
The control device for an internal combustion engine according to the present invention is applied to an internal combustion engine having an operation state variable system that can be switched in at least two different states and changes the operation state of the internal combustion engine. Accordingly, the state of the operating state variable system is switched. Specifically, as an operating state variable system,
- an intake valve or at least one of opening and closing conditions of the exhaust valves (e.g., valve lift and working angle) having a variable valve mechanism for controlling the charging efficiency of the intake air into the combustion chamber as a variable (claim 1 ),
A variable intake system that makes the intake mode of air into the combustion chamber variable (claim 2 ),
A variable compression ratio system that appropriately changes the compression ratio by changing the volume in the combustion chamber at the top dead center or the bottom dead center of the internal combustion engine (Claim 3 );
However, the present invention can be applied to any apparatus that involves a change in the operating state of the internal combustion engine. As the variable intake system, there are a variable intake pipe length system that changes the intake pipe length, and an intake flow generation system that generates a tumble flow or a swirl flow in the intake air into the combustion chamber by changing the shape of the intake passage.
[0008]
In particular, in the first to third aspects of the invention, a state switching characteristic that is a timing for switching the state of the operating state variable system is defined in association with the operating region of the internal combustion engine, and the state switching characteristic is based on the state switching characteristic. Switching control means for switching the state of the operating state variable system, and fluctuations in the air-fuel ratio fluctuation amount and intake air charging efficiency, which are parameter fluctuation amounts of the internal combustion engine that accompany the switching of the operating state variable system state Parameter fluctuation amount calculating means for calculating any one of the amount, the fluctuation amount of the intake air amount, and the fluctuation amount of the intake air pressure, and the state switching characteristic when the calculated parameter fluctuation amount exceeds a predetermined determination value. Characteristic correction means for correcting the image.
[0009]
In short, the operating state variable system is controlled to be switched based on a state switching characteristic defined in advance, but the behavior of the internal combustion engine varies with the switching, and unexpected torque steps and air-fuel ratio variations may occur. One factor is the variation in machine differences and changes over time. On the other hand, according to the first to third aspects , the air-fuel ratio fluctuation amount, the fluctuation amount of the intake air charging efficiency, the fluctuation of the intake air amount, which are the parameter fluctuation amounts of the internal combustion engine that are generated when the operating state variable system is switched. Any one of the amount and the variation amount of the intake air pressure is calculated each time, and the state switching characteristic is corrected when the parameter variation amount exceeds a predetermined determination value. Therefore, even if there is a machine difference variation or a change with time, a control error caused by the difference is eliminated, and the behavior of the internal combustion engine can be stabilized. Therefore, it becomes possible to prevent deterioration of drivability due to a torque step and deterioration of exhaust emission due to air-fuel ratio fluctuations. As described above, it is possible to suitably switch the state of the operating state variable system, and thus to keep the operating state of the internal combustion engine satisfactorily.
[0010]
According to a fourth aspect of the present invention, the characteristic correction means calculates a correction amount of the state switching characteristic, stores the correction amount data in the backup memory, and corrects the backup memory each time the correction amount is calculated. Update quantity data. Thereby, after the correction amount data is updated, the state switching characteristics can be optimized, and the optimal switching control of the operating state variable system can be continuously performed.
[0011]
According to a fifth aspect of the present invention, the state switching characteristic may be defined in advance as a behavior change of the internal combustion engine that does not occur when the state of the operating state variable system is switched. This prevents deterioration in drivability due to torque steps and deterioration in exhaust emissions due to air-fuel ratio fluctuations even when there is no machine difference variation or change over time and correction for the state switching characteristics is not implemented. it can.
[0012]
According to a sixth aspect of the present invention, the parameter fluctuation amount calculation means calculates the parameter fluctuation amount from the difference before and after the state change of the operating state variable system. Thereby, an unexpected change in the behavior of the internal combustion engine can be sequentially obtained.
[0014]
Further, as the driving state variable systems, and the step-variable variable systems stepwise state switching, there is a continuously variable system which is continuously state switching, also the present invention can be applied to any of these. In the case of application of the stepped variable system, as described in claim 7 , when the state of the operating state variable system is switched in a stepwise manner, the calculation of the parameter fluctuation amount by the parameter fluctuation amount calculation means and the characteristics are performed. It is preferable to perform characteristic correction by the correction means. In the case of application of a continuously variable system, as described in claim 8 , when the state of the operating state variable system is switched over a predetermined range at a time, the parameter fluctuation amount by the parameter fluctuation amount calculation means And the characteristic correction by the characteristic correction means may be performed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. In the present embodiment, an engine control system is constructed for an in-vehicle multi-cylinder gasoline engine that is an internal combustion engine. In the control system, an electronic control unit (hereinafter referred to as ECU) is used as a center to control the fuel injection amount. And control of ignition timing. In the present embodiment, a variable valve mechanism that varies the opening / closing operation conditions of at least one of the intake valve and the exhaust valve is adopted as the operating state variable system, and the intake valve into the combustion chamber is changed by this variable valve mechanism. The filling efficiency is controlled. First, an overall schematic configuration diagram of the engine control system will be described with reference to FIG.
[0016]
In the engine 10 shown in FIG. 1, an air cleaner 12 is provided at the most upstream portion of the intake pipe 11, and an air flow meter 13 for detecting the intake air amount is provided downstream of the air cleaner 12. A throttle valve 14 whose opening is adjusted by an actuator such as a DC motor and a throttle opening sensor 15 for detecting the throttle opening are provided on the downstream side of the air flow meter 13. A surge tank 16 is provided downstream of the throttle valve 14, and an intake pipe pressure sensor 17 for detecting the intake pipe pressure is provided in the surge tank 16. The surge tank 16 is connected to an intake manifold 18 that introduces air into each cylinder of the engine 10. In the intake manifold 18, an electromagnetically driven fuel injection that injects fuel near the intake port of each cylinder. A valve 19 is attached.
[0017]
An intake valve 21 and an exhaust valve 22 are respectively provided in the intake port and the exhaust port of the engine 10, and an air / fuel mixture is introduced into the combustion chamber 23 by the opening operation of the intake valve 21, and the exhaust valve 22. By the opening operation, the exhaust gas after combustion is discharged to the exhaust pipe 24. The intake valve 21 and the exhaust valve 22 are provided with variable valve mechanisms 25 and 26, respectively. Each of these variable valve mechanisms 25 and 26 has a structure that can change the valve opening / closing operation conditions such as the lift amount and valve opening timing (working angle) of each valve 21 and 22 step by step. The valve opening / closing operation conditions are appropriately adjusted according to the accelerator opening, the engine operating state, and the like. A detailed configuration example of the variable valve mechanisms 25 and 26 will be described later.
[0018]
A spark plug 27 is attached to the cylinder head of the engine 11 for each cylinder, and a high voltage is applied to the spark plug 27 at a desired ignition timing through an ignition device 28 including an ignition coil. By applying this high voltage, a spark discharge is generated between the opposing electrodes of each spark plug 27, and the air-fuel mixture introduced into the combustion chamber 23 is ignited and used for combustion.
[0019]
The exhaust pipe 24 is provided with a catalyst 31 such as a three-way catalyst for purifying CO, HC, NOx and the like in the exhaust gas, and the air-fuel ratio of the air-fuel mixture is detected on the upstream side of the catalyst 31 with exhaust gas as a detection target. Alternatively, an air-fuel ratio sensor 32 (linear air-fuel ratio sensor, oxygen sensor, etc.) for detecting rich / lean is provided. Further, the cylinder block of the engine 10 includes a coolant temperature sensor 33 that detects the coolant temperature, and a crank angle sensor 34 that outputs a rectangular crank angle signal for each predetermined crank angle of the engine (for example, at a cycle of 30 ° CA). It is attached.
[0020]
The outputs of the various sensors described above are input to the ECU 40 that controls the engine. The ECU 40 is configured mainly by a microcomputer including a CPU 41, a ROM 42, a RAM 43, a backup RAM 44, and the like, and executes various control programs stored in the ROM 42, whereby the fuel injection of the fuel injection valve 19 is performed according to the engine operating state. The amount and the ignition timing by the spark plug 27 are controlled. The backup RAM 44 functions as a backup memory that retains the stored contents by supplying backup power even after the power supply to the ECU 40 is cut off by turning off the ignition switch. The backup RAM 44 stores learning values, diagnostic data (failure diagnosis data), and the like. Used. These learning values, diagnosis data, and the like can also be configured to be stored and held in an EEPROM as a backup memory.
[0021]
Here, the configuration of the intake side variable valve mechanism 25 will be described with reference to FIG. Although any configuration can be applied to the variable valve mechanism 25, in the present embodiment, a configuration in which the valve lift can be switched between two stages for low speed and high speed will be described as an example. The variable valve mechanism 26 on the exhaust side is substantially the same as the variable valve mechanism 25 on the intake side, and a description thereof will be omitted. Further, in the following description, the description will be made on the variable valve mechanism 25 on the intake side as a control target.
[0022]
As shown in FIG. 2, the camshaft 51 is integrally provided with a low speed cam 52 and a high speed cam 53 having different lifts. The low-speed cam 52 has a relatively small lift and is formed into a cam profile that is suitable for low-speed operation of the engine. The high-speed cam 53 has a large lift over a wider angle than the low-speed cam 52, and is formed into a cam profile adapted for high-speed operation. Below the camshaft 51, a rocker shaft 54 extending in parallel with the camshaft 51 is provided, and a rocker arm 55 is swingably provided with the rocker shaft 54 as a support shaft. The upper end of the intake valve 21 is in contact with the rocking end of the rocker arm 55, and the intake valve 21 is lifted in the vertical direction in the figure as the rocker arm 55 is swung.
[0023]
Here, the rocker arm 55 includes a low-speed rocker arm provided in sliding contact with the low-speed cam 52, and a high-speed rocker arm provided adjacent to the low-speed cam arm 53 and in contact with the high-speed cam 53 (not shown). ), The intake valve 21 is lifted in conjunction with the movement of either one of the two rocker arms. That is, during low speed operation, the intake valve 21 lifts in conjunction with the rocking of the low speed rocker arm by the low speed cam 52, thereby realizing a relatively small valve lift. In contrast, during high speed operation, the intake valve 21 lifts in conjunction with the swing of the high speed rocker arm by the high speed cam 53, thereby realizing a relatively large valve lift. The movement of the low-speed rocker arm and the high-speed rocker arm is determined by invalidating or enabling the movement of the high-speed rocker arm by hydraulically driving the connecting device 56 that connects both rocker arms. It has come to be.
[0024]
The ECU 40 drives the variable valve mechanism 25 based on the engine operating state to switch between a valve lift at low speed (valve lift by the low speed cam 52) and a valve lift at high speed (valve lift by the high speed cam 53). . That is, the valve lift amount and the valve opening timing are switched while the engine operating state is monitored each time. As a specific example, switching between a valve lift at a low speed and a valve lift at a high speed is performed using the engine characteristics shown in FIG. 3 and parameters of the engine speed and the engine load (for example, accelerator opening). At this time, a switching characteristic line (corresponding to the state switching characteristic) is defined in FIG. 3 so that the output torque does not change even when the valve lift is switched, that is, the behavior of the engine 10 does not change. When the engine operating state changes so as to cross this switching characteristic line, the valve lift is switched.
[0025]
FIG. 4 shows the air-fuel ratio fluctuation amount Δλ (corresponding to the parameter fluctuation amount) with respect to the engine speed at the time of switching the valve lift. (A) shows Δλ when switching from low speed to high speed, and (b) shows high speed → low speed. Δλ at the time of switching is shown. However, the engine load (for example, accelerator opening) is constant. In FIG. 4, the air-fuel ratio fluctuation amount Δλ is the smallest when the engine speed is about 3500 rpm in any switching from low speed → high speed and high speed → low speed. According to the switching characteristic line of FIG. The valve lift is switched at a switching point at which is the smallest (for example, engine speed = about 3500 rpm).
[0026]
By the way, when the valve lift is switched on the switching characteristic line, the behavior change of the engine 10 originally does not occur, but it is considered that the behavior change of the engine 10 occurs due to the machine difference variation and the change with time. In this case, unexpected torque steps and air-fuel ratio fluctuations occur due to changes in the behavior of the engine 10. For example, as shown in FIG. 5, the Δλ behavior at the time of switching from low speed to high speed changes from a solid line to a two-dot chain line due to machine difference variation and changes with time. Then, when the valve lift is switched at an engine speed of about 3500 rpm based on the switching characteristic line, an air-fuel ratio fluctuation amount Δλ is generated. As a result, exhaust emission deterioration due to the air-fuel ratio fluctuation or a torque step is caused. This leads to a deterioration in drivability. Therefore, in the present embodiment, it is proposed to perform correction for the switching characteristic line based on the air-fuel ratio fluctuation amount Δλ at the time of valve lift switching. The ECU 40 performs the valve lift switching control, the calculation of the air-fuel ratio fluctuation amount Δλ, and the correction for the switching characteristic line. That is, in the present embodiment, the ECU 40 constitutes “switching control means”, “parameter fluctuation amount calculation means”, and “characteristic correction means”.
[0027]
Next, variable valve lift control performed by the ECU 40 will be described. FIG. 6 is a flowchart showing the valve lift control process, and this process is performed by the CPU 41 in the ECU 40, for example, at every predetermined crank angle (in this embodiment, every 30 ° CA).
[0028]
In FIG. 6, first, in step S101, various parameters such as the engine speed and the accelerator opening indicating the engine operating state are read. Thereafter, in step S102, reference is made to the switching characteristics (specifically, the table data corresponding to the switching characteristics line in FIG. 3) set by the engine speed, accelerator opening, etc., and in the subsequent step S103, the current state is the valve lift switching. It is determined whether it is the implementation time. If the current state is not the timing for switching the valve lift, this process is terminated as it is. In steps S102 and S103, when a learning value (correction amount data) relating to the switching characteristics exists in the backup RAM 44, the valve lift switching determination is performed using the learning value.
[0029]
If the current timing is the valve lift switching timing, the process proceeds to step S104, and a control command is output to the variable valve mechanism 25 (or the exhaust-side variable valve mechanism 26) to perform valve lift switching. . Thereby, the variable valve mechanism 25 is driven, and the switching from the valve lift by the low speed cam 52 to the valve lift by the high speed cam 53 or vice versa is performed. Thereafter, in step S105, a parameter fluctuation amount before and after the valve lift switching is calculated. Specifically, the detected value of the air-fuel ratio sensor 32 is used to calculate the air-fuel ratio fluctuation amount Δλ as the parameter fluctuation amount from the difference at every predetermined sampling interval. Alternatively, the detected value of the air-fuel ratio sensor 32 is also used to calculate the air-fuel ratio fluctuation amount Δλ as the parameter fluctuation amount from the difference between the air-fuel ratio value before the valve lift switching and the peak value of the air-fuel ratio change accompanying the valve lift switching. .
[0030]
Thereafter, in step S106, the calculated parameter fluctuation amount (air-fuel ratio fluctuation amount Δλ) is compared with a predetermined value set in advance, and if the parameter fluctuation amount is less than the predetermined value, it is determined that the switching characteristic is not corrected. Then, this process is finished as it is. If the parameter fluctuation amount is equal to or greater than the predetermined value, it is determined that the switching characteristic needs to be corrected, and the process proceeds to step S107.
[0031]
In step S107, the learning value of the switching characteristic is updated based on the calculated parameter fluctuation amount (air-fuel ratio fluctuation amount Δλ). The learning value update will be described. Using the table of FIG. 7 set corresponding to the parameter fluctuation amount (air-fuel ratio fluctuation amount Δλ), the correction amount corresponding to the rotational speed is calculated according to the Δλ value each time. At this time, if the Δλ value is a rich value, a positive correction amount is calculated, and if the Δλ value is a lean value, a negative correction amount is calculated. If there is a correction amount that already exists in the backup RAM 44, the correction amount is read from the backup RAM 44 and the current value of the correction amount is added to calculate a new correction amount. Then, the correction amount after the addition is written in the backup RAM 44 as a learning value.
[0032]
For example, in the case of FIG. 5, the air-fuel ratio fluctuates to the rich side by switching the valve lift when the engine speed is about 3500 rpm. In this case, since it is considered that the optimum switching characteristic line is shifted to the high rotation side, the engine speed that is the determination parameter for the switching characteristic is corrected to the high rotation side. Conversely, when the air-fuel ratio fluctuates to the lean side, the optimum switching characteristic point is considered to have shifted to the low speed side, so the engine speed, which is the parameter for determining the switching characteristics, is low. It is corrected to.
[0033]
More specifically, using the time chart of FIG. 8, at time t1, the engine speed reaches a specified value (eg, 3500 rpm) on the switching characteristic line, and low-speed to high-speed valve lift switching is performed. At this time, for example, when the air-fuel ratio fluctuation to the rich side occurs due to machine difference variation or temporal change, the correction amount (learning value) is updated based on the air-fuel ratio fluctuation amount Δλ. In subsequent valve lift control, the updated correction amount (learned value) is appropriately used to switch the valve lift.
[0034]
According to the embodiment described above in detail, the following excellent effects can be obtained.
[0035]
The parameter fluctuation amount (air-fuel ratio fluctuation amount Δλ) generated at the time of switching the valve lift is calculated each time, and the switching characteristic is corrected when the parameter fluctuation amount exceeds a predetermined judgment value. Even if there is a change, the control error caused by the change is eliminated, and the engine behavior can be stabilized. Therefore, it becomes possible to prevent deterioration of drivability due to a torque step and deterioration of exhaust emission due to air-fuel ratio fluctuations. As described above, it is possible to suitably switch the valve lift, and thus to keep the engine operating state satisfactorily.
[0036]
Since the correction amount data of the switching characteristic is stored and held in the backup RAM 44 as a learning value and is used as appropriate for the subsequent valve lift switching, the optimum valve lift control can be continuously performed while optimizing the switching characteristic. .
[0037]
In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.
[0038]
In the valve lift control, a learning value (correction amount data) is calculated for each engine operation region, and the learning value is stored and held in the backup RAM 44 corresponding to the operation region. The learning value is updated for each engine operation region. In this case, the same characteristic correction is not performed in the entire operation region, but optimal characteristic correction is performed for each engine operation region, so that highly accurate valve lift control can be realized.
[0039]
Instead of a learning value (correction amount data) corresponding to the rotational speed, a learning value (correction amount data) corresponding to the engine load may be calculated. Instead of updating the correction amount data by learning, it is also possible to update the switching characteristics themselves.
[0040]
In the above embodiment, the engine behavior is monitored using the air-fuel ratio fluctuation amount as the parameter fluctuation amount, but this is changed, and the fluctuation amount of the charging efficiency of the intake air is used as the parameter fluctuation amount. In this case, the engine behavior can be monitored. In addition, a variation amount of the intake air amount and a variation amount of the intake air pressure may be used.
[0041]
In the above embodiment, the stepped variable system in which the valve lift is switched in stages is applied as the variable valve mechanism, but instead, the linear variable system in which the valve lift is switched linearly (continuously). It is also possible to apply. In the case of application of the linear variable system, it is preferable to calculate the parameter fluctuation amount and correct the characteristics when the valve lift is switched over a predetermined width at a time.
[0042]
In the above-described embodiment, the application example to the variable valve system has been described.
・ Variable intake system that makes the intake mode of air into the combustion chamber variable,
A variable compression ratio system that appropriately changes the compression ratio by changing the volume in the combustion chamber at the piston top dead center or bottom dead center of the internal combustion engine;
It is also possible to apply another operating state variable system such as this to the present invention. In these applications, the same excellent effect can be obtained. As the variable intake system, a variable intake pipe length system that changes the intake pipe length into multiple patterns, or a tumble flow or swirl flow is generated in the intake air into the combustion chamber by changing the shape of the intake passage into multiple patterns. There is an intake flow generation system. Known variable compression ratio systems include those that change the position of the cylinder bore and cylinder head, those that change the movement by setting a second piston, and those that change the eccentric position of the crankshaft.
[0043]
Moreover, it can be applied not only to gasoline engines but also to diesel engines.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an engine control system in an embodiment of the invention.
FIG. 2 is a configuration diagram for explaining a variable valve mechanism.
FIG. 3 is a graph showing switching characteristics of a valve lift.
FIG. 4 is an explanatory diagram for explaining the behavior of the air-fuel ratio fluctuation amount at the time of switching the valve lift.
FIG. 5 is an explanatory diagram for explaining the behavior of the air-fuel ratio fluctuation amount at the time of switching the valve lift.
FIG. 6 is a flowchart showing a valve lift control process.
FIG. 7 is an explanatory diagram showing an example of a correction amount calculation table.
FIG. 8 is a time chart for explaining a procedure for calculating a correction amount;
[Explanation of symbols]
10 ... Engine,
21 ... Intake valve,
22 ... exhaust valve,
23 ... Combustion chamber,
25, 26 ... Variable valve mechanism,
40 ... ECU,
41 ... CPU,
44 ... Backup RAM.

Claims (8)

An operating state variable system having a variable valve mechanism that can be switched in at least two different states and that controls the charging efficiency of intake air into the combustion chamber by changing the opening / closing operation condition of at least one of the intake valve and the exhaust valve. In an internal combustion engine control device that is applied to an internal combustion engine that switches the state of the operating state variable system according to the engine operating range in each case,
Switching control means for defining a state switching characteristic that is a timing for switching the state of the operating state variable system in correspondence with an operating region of the internal combustion engine, and for switching the state of the operating state variable system based on the state switching characteristic; ,
Air-fuel ratio fluctuation amount, fluctuation amount of intake air charging efficiency, fluctuation amount of intake air amount, fluctuation amount of intake air pressure, which are parameter fluctuation amounts of the internal combustion engine generated by the switching of the operating state variable system state A parameter fluctuation amount calculating means for calculating any one of
A characteristic correction unit that corrects the state switching characteristic when the calculated parameter fluctuation amount exceeds a predetermined determination value;
A control apparatus for an internal combustion engine, comprising: The operating state variable system is applied to an internal combustion engine having a variable intake system that can be switched between at least two different states and variable in the intake mode of the air into the combustion chamber, and is adapted to the engine operating range in each case. In the control device for an internal combustion engine configured to switch the state of the operating state variable system,
  Switching control means for defining a state switching characteristic that is a timing for switching the state of the operating state variable system in correspondence with an operating region of the internal combustion engine, and for switching the state of the operating state variable system based on the state switching characteristic; ,
  Air-fuel ratio fluctuation amount, fluctuation amount of intake air charging efficiency, fluctuation amount of intake air amount, fluctuation amount of intake air pressure, which are parameter fluctuation amounts of the internal combustion engine generated by the switching of the operating state variable system state A parameter fluctuation amount calculating means for calculating any one of
  A characteristic correction unit that corrects the state switching characteristic when the calculated parameter fluctuation amount exceeds a predetermined determination value;
A control apparatus for an internal combustion engine, comprising: An internal combustion engine having a variable compression ratio system that can be switched between at least two different states as an operating state variable system and changes the compression ratio as appropriate by changing the volume in the combustion chamber at the piston top dead center or bottom dead center of the internal combustion engine In the control device for an internal combustion engine, which is adapted to switch the state of the operating state variable system in accordance with the engine operating region in each case,
  Switching control means for defining a state switching characteristic that is a timing for switching the state of the operating state variable system in correspondence with an operating region of the internal combustion engine, and for switching the state of the operating state variable system based on the state switching characteristic; ,
  Air-fuel ratio fluctuation amount, fluctuation amount of intake air charging efficiency, fluctuation amount of intake air amount, fluctuation amount of intake air pressure, which are parameter fluctuation amounts of the internal combustion engine generated by the switching of the operating state variable system state A parameter fluctuation amount calculating means for calculating any one of
  A characteristic correction unit that corrects the state switching characteristic when the calculated parameter fluctuation amount exceeds a predetermined determination value;
A control apparatus for an internal combustion engine, comprising: The characteristic correction means calculates the correction amount of the state switching characteristic, stores the correction amount data in the backup memory, and updates the correction amount data of the backup memory every time the correction amount is calculated. The control apparatus for an internal combustion engine according to any one of claims 1 to 3 . The control of the internal combustion engine according to any one of claims 1 to 4, wherein the state switching characteristic is preliminarily defined as that the behavior change of the internal combustion engine does not occur when the state of the operating state variable system is switched. apparatus. The parameter change amount calculation unit, a control apparatus for an internal combustion engine according to any one of claims 1 to 5, characterized in that to calculate the parameter variation amount from a difference between before and after the time of the state switching of the operating state variable system. The operating state variable system is a stepped variable system whose state is switched in stages, and when the state of the operating state variable system is switched in stages, the parameter fluctuation amount is calculated by the parameter fluctuation amount calculating means, and the internal combustion engine control device according to any one of claims 1 to 6 which comprises carrying out the characteristic correction by said characteristic correction means. The operating state variable system is a continuously variable system in which the state is continuously switched, and when the state of the operating state variable system is switched over a predetermined range at a time, the parameter variation amount by the parameter variation amount calculation means The internal combustion engine control apparatus according to any one of claims 1 to 6 , wherein the calculation of the characteristic and the characteristic correction by the characteristic correction means are performed.

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