JP5170691B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine configured to control energy in an exhaust system of the internal combustion engine, for example, heat quantity.

  Patent Document 1 discloses target value setting means for setting a target value of exhaust energy to be supplied to a catalyst disposed in an exhaust passage of an internal combustion engine, and exhaust energy for estimating actual exhaust energy supplied to the catalyst. A control device for an internal combustion engine is disclosed that includes estimation means and parameter control means for controlling control parameters of the internal combustion engine so that the target values of the exhaust energy and the actual exhaust energy match. The parameter control means can include ignition timing control means for controlling the ignition timing. The device described in Patent Document 1 having such a configuration is intended to realize, for example, good exhaust emission characteristics.

JP 2004-44527 A JP 2007-321577 A JP 2006- 97588 A

  By the way, the exhaust energy, specifically the exhaust heat amount, can be adjusted by controlling various control objects based on a plurality of control parameters. However, control responsiveness differs for each control parameter. For example, the ignition timing has a relatively fast response, but the intake charge efficiency has a relatively slow response. Therefore, in order to more appropriately control the exhaust energy, it is effective to consider the control responsiveness of the control parameter.

  Therefore, the present invention has been made in view of such a point, and an object thereof is to more appropriately control the exhaust energy in consideration of the responsiveness of the control parameter.

  In order to achieve the above object, an internal combustion engine control apparatus according to the present invention is an internal combustion engine control apparatus configured to control exhaust energy, wherein a difference between target exhaust energy and actual exhaust energy is a predetermined amount. At the above time, selecting means for selecting one combination in consideration of the responsiveness of a plurality of control parameters from a plurality of combinations of a plurality of control parameter values of the internal combustion engine having target exhaust energy feasibility Control means for controlling the internal combustion engine based on one combination of the values of the plurality of control parameters selected by the selection means.

  Preferably, the selection means includes, for each combination of a plurality of combinations of a plurality of control parameter values, an aerial distance value calculation means that calculates an imaginary distance value considering the responsiveness of the plurality of control parameters, and the aerial distance value The minimum value selecting means for selecting the minimum value from among the plurality of fictitious distance values calculated by the calculating means, and the values of the plurality of control parameters corresponding to the minimum fictitious distance value selected by the minimum value selecting means. And determining means for determining one combination of the two to match the target exhaust energy.

  The selection means includes correlation data between the exhaust energy and a plurality of control parameters stored in the storage device, actual exhaust energy calculation means for calculating actual exhaust energy in the exhaust system of the internal combustion engine, and the internal combustion engine When the difference between the target exhaust energy calculating means for calculating the target exhaust energy in the exhaust system and the actual exhaust energy calculated by the actual exhaust energy calculating means and the target exhaust energy calculated by the target exhaust energy calculating means is a predetermined amount or more. And a plurality of combination selection means for searching the correlation data based on the target exhaust energy and selecting a plurality of combinations of a plurality of control parameter values.

  The exhaust energy is preferably the exhaust heat quantity.

  Further, it is preferable to further include data update means for updating the correlation data using the actual exhaust energy detected or estimated by the actual exhaust energy detection means.

1 is a schematic configuration diagram of an internal combustion engine to which an embodiment of the present invention is applied. 3 is a flowchart according to an embodiment of the present invention. It is the graph which represented the example of the change of the temperature of exhaust gas by application of this invention with the continuous line, and represented the example of the change of the temperature of the conventional exhaust gas with the dotted line.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an internal combustion engine to which a control device for an internal combustion engine according to the present invention is applied. The internal combustion engine 10 shown in FIG. 1 generates power by burning a fuel / air mixture in a combustion chamber 14 formed in a cylinder block 12 and reciprocating a piston 18 in the cylinder 16. It is. Although only one cylinder is shown in FIG. 1, the internal combustion engine 10 is preferably configured as a multi-cylinder engine, and the internal combustion engine 10 of the present embodiment is configured as a four-cylinder engine, for example.

  An intake port facing each combustion chamber 14 is connected to an intake manifold 20. A surge tank 22 and an intake pipe 24 are sequentially connected to the upstream side of the intake manifold 20. The intake pipe 24 is connected to an air intake (not shown) via an air cleaner 26. A throttle valve (in this embodiment, an electronically controlled throttle valve) 28 is incorporated in the middle of the intake pipe 24 (between the surge tank 22 and the air cleaner 26).

  On the other hand, an exhaust port facing each combustion chamber 14 is connected to an exhaust manifold 30, and an exhaust pipe 32 is connected downstream of the exhaust manifold 30. Connected to the exhaust pipe 32 are a front-stage catalyst device 34 including a three-way catalyst and a rear-stage catalyst device 36 including a NOx storage reduction catalyst.

  In the cylinder head of the internal combustion engine 10, an intake valve Vi that opens and closes an intake port and an exhaust valve Ve that opens and closes an exhaust port are disposed for each combustion chamber 14. Each intake valve Vi and each exhaust valve Ve are opened and closed by a valve operating mechanism (not shown) having a variable valve timing function. Further, the internal combustion engine 10 has a number of spark plugs 40 corresponding to the number of cylinders, and the spark plugs 40 are disposed in the cylinder heads so as to face the corresponding combustion chambers 14.

  Further, as shown in FIG. 1, the internal combustion engine 10 has a plurality of injectors 42, and the injectors 42 are arranged in the cylinder head so as to face the corresponding combustion chambers 14. In the internal combustion engine 10, fuel such as gasoline is directly injected from the injectors 42 toward the recesses 18 a of the pistons 18 in the combustion chambers 14 in a state where air is sucked into the combustion chambers 14. As a result, in the internal combustion engine 10, it becomes possible to form (stratify) an air-fuel mixture layer of fuel and air in the vicinity of the spark plug 40 in a state separated from the surrounding air layer. Can be used to perform stable stratified combustion.

  The throttle valve 28, each spark plug 40, each injector 42, and the valve mechanism are electrically connected to an ECU 50 that substantially functions as a control device for the internal combustion engine 10. The ECU 50 includes a CPU, a ROM, a RAM, an input / output port, a storage device, etc., all not shown. Various sensors are electrically connected to the ECU 50 via an A / D converter or the like, for example, an air flow meter 52 for detecting an intake air amount. The ECU 50 uses the various maps stored in the storage device and the throttle valve 28, the spark plug 40, the injector 42, the valve operating mechanism, etc. so as to obtain a desired output based on the detection values of various sensors. To control.

  As shown in FIG. 1, the sensors connected to the ECU 50 include a crank angle sensor 54. The crank angle sensor 54 is a magnetic sensor or a photoelectric sensor including a rotor plate (signal plate) fixed to the crankshaft, and the like, and gives a pulse signal indicating the rotation angle of the crankshaft to the ECU 50 every minute time. In addition, the internal combustion engine 10 has in-cylinder pressure sensors 56 including semiconductor elements, piezoelectric elements, optical fiber detection elements, and the like corresponding to the number of cylinders. Each in-cylinder pressure sensor 56 is disposed on the cylinder head so that the pressure receiving surface faces the corresponding combustion chamber 14, and is electrically connected to the ECU 50 via an A / D converter (not shown). Each in-cylinder pressure sensor 56 outputs an electric signal corresponding to the pressure in the combustion chamber 14, that is, the in-cylinder pressure. An output signal from each in-cylinder pressure sensor 56 is sequentially given to the ECU 50 every predetermined time (predetermined crank angle) to obtain a pressure value (for example, absolute pressure), and is then stored in the ECU 50 in association with the crank angle. A predetermined amount is stored and held in the area (buffer).

  As described above, the internal combustion engine 10 is controlled by the ECU 50 so as to achieve an optimal operating state based on various detection values based on output signals from various sensors. In particular, here, the control of the throttle valve 28, the ignition plug 40, the injector 42, and the valve operating mechanism is taken into consideration. Below, the control example is demonstrated based on the flowchart of FIG. In the flowchart of FIG. 2, each target control is considered in consideration of the responsiveness of a plurality of control parameters based on the responsiveness of the spark plug 40, the throttle valve 28, the injector 42, and the valve mechanism that are the control targets. It is a flowchart showing the flow which calculates | requires a value.

  However, in the present embodiment, the selection unit that selects one combination of the plurality of control parameters in consideration of the responsiveness of the plurality of control parameters includes a part of the ECU 50. Further, the control means for controlling the internal combustion engine includes a part of the ECU 50.

  In order to properly operate the internal combustion engine 10, the ignition plug 40, the throttle of the internal combustion engine 10 is used based on detection values based on output signals from various sensors and the like using various maps stored in the storage device. When the valve 28, the injector 42, the valve operating mechanism, and the like are controlled, the flow of FIG. 2 is executed. 2 is performed from the start of the internal combustion engine 10. However, after the internal combustion engine 10 is started, for example, the flow of FIG. 2 may be executed while the internal combustion engine 10 is in an operating state from when the operating state of the internal combustion engine 10 is stabilized to some extent. For example, the start time when the flow of FIG. 2 is executed may be when a predetermined number of cycles (four strokes of intake, compression, combustion / expansion, and exhaust) are completed. Here, the flowchart of FIG. 2 is repeated for each cycle of each cylinder 16, but various periods can be set for repeating the flowchart of FIG.

The ECU 50 first acquires the in-cylinder pressure at a predetermined time in step S201. This in-cylinder pressure is obtained based on an output signal from the in-cylinder pressure sensor 56. Here, the in-cylinder pressure P (k, θ = θ _EVO ) when the exhaust valve Ve is opened (EVO) in each cycle is acquired. As described above, in-cylinder pressure is stored and held in a predetermined storage area in association with the crank angle, and by searching the related data with the crank angle when the exhaust valve is opened, the exhaust valve Ve is opened. The in-cylinder pressure at the time is acquired. However, the subscript "k" in-cylinder pressure P when the opening of the exhaust valve Ve (EVO) (k, θ = θ EVO) represents the k-th cycle, the subscript "theta" represents the crank angle. In addition, the same subscript is used also in the code | symbol shown below.

The in-cylinder temperature when the exhaust valve Ve is opened is calculated using the in-cylinder pressure acquired in step S201. The in-cylinder temperature is calculated based on the gas equation of state, that is, based on the equation (1). However, T (k, θ = θ _EVO ) is the in-cylinder temperature at the crank angle θ _EVO corresponding to the opening of the exhaust valve at the kth cycle, and V (k, θ = θ _EVO ) is when the exhaust valve is opened. In-cylinder volume at the corresponding crank angle θ _EVO , R is a gas constant. Therefore, V (k, θ = θ _EVO ) and R are unambiguously determined constants, and here, since they are predetermined data stored, P (k, θ = By using (θ _EVO ), T (k, θ = θ _EVO ) can be obtained.

Next, in step S205, an actual exhaust heat amount (actual exhaust heat amount) Q (k) is calculated as actual exhaust energy (actual exhaust energy) in the current cycle. The calculation of the actual exhaust heat quantity is performed based on the equation (2). However, T (k, θ = θ _EVO ) is the value calculated in step S203, and T ₀ is a constant, for example, 273K. Q ₀ is the amount of heat when the temperature is T ₀ , which is a constant and recorded in advance here. C _P (T) is a constant pressure specific heat and is a function of temperature. A part of the ECU 50 that performs the calculation in step S205 is included in the means for calculating the actual exhaust energy, that is, the actual exhaust heat amount.

  Then, using the actual exhaust heat quantity Q (k) thus obtained in step S205, correlation data between the exhaust heat quantity as exhaust energy and a plurality of control parameters is updated in step S207. The correlation data is data that is constructed in advance based on experiments or various theoretical operations, and is recorded in advance in a storage device. The correlation data is recorded in an updatable manner and is learned as the operation time (operation time) of the internal combustion engine 10 elapses. The plurality of control objects are the ignition plug 40, the throttle valve 28, the injector 42, and the valve mechanism described above. Here, the plurality of control parameters for controlling them are the engine rotational speed NE. , Intake charge efficiency KL, residual gas ratio re of the in-cylinder gas, air-fuel ratio of the in-cylinder gas (air-fuel ratio of the in-cylinder mixture before combustion) raf, and ignition timing SA. Here, the engine speed NE for updating (learning) is obtained based on the output signal from the crank angle sensor 54. The intake air charging efficiency KL is obtained based on an output signal from the air flow meter 52. The residual gas ratio re may be obtained based on the valve timings and lift amounts of the intake / exhaust valves Vi and Ve, but is calculated here as described later. The air-fuel ratio raf of the in-cylinder gas may be obtained using an air-fuel ratio sensor provided here, but here it is calculated as described later. The ignition timing SA is read from recorded data used for control.

  The values of the plurality of control parameters are correlated with the exhaust heat quantity in the correlation data. Then, the correlation data is updated, that is, corrected while associating the actual exhaust heat quantity obtained in step S205 with the exhaust heat quantity of the correlation data using various theoretical calculations as necessary. Note that a part of the ECU 50 that performs data update in step S207 is included in the data update means.

  Here, how to obtain the residual gas ratio re and the air-fuel ratio raf of the in-cylinder gas will be described. However, the details are disclosed in Patent Document 2 and Patent Document 3 to which the present applicant is the applicant, and here, it is described that it can be applied to the present invention, and only the outline is described below.

  A method of obtaining the residual gas ratio re is disclosed in Patent Document 2. Based on the in-cylinder pressure in the cylinder, the volume in the cylinder (in-cylinder volume), and the temperature of the gas in the cylinder (in-cylinder gas temperature), the amount of residual gas remaining in the cylinder is calculated. Specifically, by substituting the in-cylinder pressure, the in-cylinder volume, and the in-cylinder gas temperature into the gas equation of state, the total gas amount in the cylinder (in-cylinder gas amount) is obtained, and the air flow is calculated from this in-cylinder gas amount. The residual gas quantity is obtained by subtracting the fresh gas quantity obtained from the meter. And the residual gas ratio re can be calculated | required by calculating the ratio with respect to the cylinder internal gas amount of residual gas amount. The in-cylinder gas temperature can be calculated based on, for example, the cylinder wall temperature (in-cylinder wall temperature), and the in-cylinder wall temperature can be calculated based on the coolant temperature. The in-cylinder gas temperature can be calculated based on the ratio of the in-cylinder gas temperature at two predetermined crank angles and the above-described in-cylinder wall temperature. Specifically, the predetermined two crank angles are set to two points such that there is no gas inflow / outflow in the cylinder and fuel ignition is not performed while the crank angle changes. That is, two points of the crank angle during the compression stroke are selected. By setting the two crank angles in this way, the change in the in-cylinder gas temperature when the crank angle changes is uniquely determined by the in-cylinder wall temperature. Therefore, the in-cylinder gas temperature can be accurately obtained based on the relationship between the in-cylinder gas temperature ratio and the in-cylinder wall temperature. The ratio of the in-cylinder gas temperature is obtained by Boyle-Charle's law using the in-cylinder pressure and the in-cylinder volume at two predetermined crank angles.

  A method for obtaining the air-fuel ratio raf of the in-cylinder gas is disclosed in Patent Document 3. In this method, based on the in-cylinder pressure obtained using the in-cylinder pressure sensor, the combustion time from the start of combustion in the combustion chamber until the combustion is substantially completed is calculated. On the other hand, there is a correlation between the air-fuel ratio in the combustion chamber of the internal combustion engine and the combustion speed of the air-fuel mixture (fuel) in the combustion chamber, and the combustion speed of the air-fuel mixture in the combustion chamber is combusted in the combustion chamber. Is closely related to the combustion time from the start of the combustion until the combustion is substantially completed. The air-fuel ratio can be obtained by searching an air-fuel ratio map obtained by paying attention to such a relationship and defining the correlation between the combustion time and the air-fuel ratio in the combustion chamber with the combustion time calculated as described above. .

  Here, returning to the flowchart of FIG. 2, step S209 subsequent to step S207 is performed. In step S209, the exhaust heat quantity (target exhaust energy) as exhaust energy (target exhaust energy) targeted for control of the internal combustion engine 10 obtained from the engine operating state and the operation request to the internal combustion engine 10 (e.g., estimated from the accelerator opening). It is determined whether or not the difference between the heat quantity) and the actual exhaust heat quantity obtained in step S205 is within a predetermined quantity range. Here, the target exhaust heat quantity is the target value of the exhaust heat quantity in the engine control in the next cycle, and the sign Qr (k + 1) is used for the sign Q (k) for the actual exhaust heat quantity. It is determined whether or not the difference (magnitude) between the actual exhaust heat quantity Q (k) and the target exhaust heat quantity Qr (k + 1) is less than a predetermined difference ε. The target exhaust heat amount may be determined from the amount of heat input to or possessed by the catalysts of the catalyst devices 34 and 36, or may be determined from the heat amount of the exhaust passage estimated from the temperature of the exhaust passage. Can be calculated based on the calculation method and the calculation standard. For example, when the target exhaust heat amount is determined from the heat amount of the catalyst of the catalyst devices 34 and 36, the temperatures of the exhaust passages on the upstream and downstream sides of the catalyst are detected using a temperature sensor or the like, and the target exhaust heat amount is determined from the temperature difference therebetween. Can be calculated by calculating using a predetermined arithmetic expression. Note that a part of the ECU 50 that performs a part of the calculation in step S209 is included in the means for calculating the target exhaust energy, that is, the target exhaust heat amount. In addition, a part of the ECU 50 that performs a part of the calculation in step S209 is included in the comparison unit that compares the actual exhaust energy and the target exhaust energy.

  If negative in step S209, that is, if the difference between the actual exhaust heat quantity Q (k) and the target exhaust heat quantity Qr (k + 1) is greater than or equal to the predetermined difference ε, in step S211, the target exhaust heat quantity Qr (k + 1). A plurality of combinations of the values of the plurality of control parameters are selected from the correlation data. The plurality of combinations of the values of the plurality of control parameters selected in this way are combinations having the possibility of realizing the target exhaust heat quantity Qr (k + 1). Note that a part of the ECU 50 that performs the calculation in step S211 is included in a plurality of combination selection means for selecting a plurality of combinations of a plurality of control parameter values.

  Specifically, by searching the correlation data with the target exhaust heat quantity Qr (k + 1) and extracting a plurality of exhaust heat quantities approximate to the target exhaust heat quantity Qr (k + 1) from the correlation data, Multiple combinations of these are obtained. In other words, a combination of a plurality of control parameter values for each of the plurality of exhaust heat amounts thus extracted is selected as a plurality of combinations of a plurality of control parameter values.

For example, three combinations shown below as Equation (3) are selected. However, in Expression (3), they are expressed as determinants. In the formula (3), three combinations of the first combination CND1, the second combination CND2, and the third combination CND3 are shown, but as described above, there are two or more combinations, any number of combinations. Good. However, it is allowed to be just one combination. Note that a combination number is assigned to the engine speed NE, the intake charging efficiency KL, the residual gas ratio re of the in-cylinder gas, the air-fuel ratio raf of the in-cylinder gas, and the ignition timing SA in the expression (3), for example, The first combination CND1 includes the engine speed NE ₁ , the intake charging efficiency KL ₁ , the in-cylinder gas residual gas ratio re ₁ , the in-cylinder gas air-fuel ratio raf ₁ , and the ignition timing SA ₁ . However, the engine speed NE may be removed from each of these combinations.

  Then, from the combination of the values of the plurality of control parameters selected in step S211, an aerial distance value R is obtained for each of the combinations in step S213. Here, the aerial distance value R is based on actual exhaust energy for comparing a plurality of combinations of a plurality of control parameters under the same dimension in consideration (based on) responsiveness of each of the plurality of control parameters. Defined as the fictitious normalized distance to the target exhaust energy. Specifically, here, the overhead distance value is obtained based on Expression (4).

Here, each term of the equation (4) is a term regarding the intake charge efficiency, the residual gas ratio, the in-cylinder air-fuel ratio, and the ignition timing in order from the front. Here, from the respective values in the current cycle (k) Is equivalent to the distance value. Each of KLunit ³ / Qunit, reunit ³ / Qunit, rafunit ³ / Qunit, and SAunit ³ / Qunit is a constant for making dimensionless. Further, in the equation (4), a constant considering the responsiveness of each control parameter, specifically, the reciprocal of the time from when the actuator for each control object is controlled until the exhaust heat quantity is affected is expressed as C _KL , C _re , C _raf , and C _sa have a relationship of “C _sa > C _raf > C _re > C _KL ”. ∂Q / ∂KL, ∂Q / ∂re, ∂Q / ∂raf, and ∂Q / ∂SA are the actual values when the intake charge efficiency, residual gas ratio, in-cylinder air-fuel ratio, and ignition timing are controlled. This is a value representing the degree of influence on the exhaust heat quantity Q (k). When the correlation data is mapped, these correspond to the slope of the actual exhaust heat quantity Q (k). Further, the subscript i in the formula (4) changes as 1, 2,..., And the aerial distance value R (1) in the first combination CND1 is set to 1 as the control parameter of the first combination CND1. It is obtained by substituting the value into equation (4). Note that a part of the ECU 50 that performs the calculation in step S213 is included in the aerial distance value calculation means.

  Thus, the minimum value is obtained (selected) from the fictitious distance values obtained for each combination in step S215. Note that a part of the ECU 50 that performs the calculation in step S215 is included in the minimum value selection means. In this way, the routine is terminated and repeated. If the determination in step S209 is affirmative, that is, if the difference between the actual exhaust heat quantity Q (k) and the target exhaust heat quantity Qr (k + 1) is less than the predetermined difference ε, the routine at that time is ended and repeated. It is.

  The ECU 50 determines one combination CND of a plurality of control parameters corresponding to the minimum value (minimum overhead distance value) of the overhead distance value thus determined. Then, the plurality of control objects are set such that the plurality of control parameters (here, the intake charging efficiency, the residual gas ratio, the in-cylinder air-fuel ratio, the ignition timing) are a combination of the values thus determined. Each is controlled. In addition, a part of ECU50 which calculates | requires one combination CND of a some control parameter is contained in a determination means.

  Summarizing the above, in the present invention, when the difference between the target exhaust energy and the actual exhaust energy is a predetermined amount or more, the values of a plurality of control parameters of the internal combustion engine having the possibility of realizing the target exhaust energy. By comparing the fictitious distance values in each combination considering the responsiveness of the plurality of control parameters, one combination is selected, and thus one combination of the plurality of control parameter values thus selected is selected. Based on this, the internal combustion engine is controlled. Therefore, it becomes possible to appropriately control the exhaust energy of the internal combustion engine.

  That is, since a plurality of objects to be controlled are controlled using the values of the control parameters thus obtained, the exhaust energy, particularly the exhaust heat amount, can be controlled to a desired level. For example, even when the engine is started, the transition of the exhaust gas temperature is suppressed as shown by the dotted line in FIG. 3, and according to the present invention, the exhaust gas temperature is reduced as shown by the solid line in FIG. It can be raised smoothly and quickly. Therefore, for example, it is possible to improve the warm-up performance when starting the engine, or to prevent the catalyst provided in the exhaust passage from being melted due to the exhaust gas temperature becoming too high. Become. In addition, since the overhead distance value is used as described above, it is possible to achieve both the appropriate control of the exhaust energy and the securing of the response.

  In addition, this makes it possible to maximize the capability of the internal combustion engine 10. For example, the ignition timing set in this way can be an ignition timing with a minimum margin, so that it can have the maximum amplitude. Such margin is the same for the values of other control parameters.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, the plurality of control parameters are not limited to the above-described control parameters, and may be configured with only a control parameter different from the above-described control parameters, with less or more.

  Moreover, in the said embodiment, although the internal combustion engine was made into the spark ignition type engine, it may be a compression ignition type engine. Alternatively, the internal combustion engine to which the present invention is applied may be a port injection type internal combustion engine, and the present invention is applicable to various internal combustion engines.

  While the present invention has been described based on the embodiments and the like, the present invention is not limited to this. The present invention includes all modifications, applications, and equivalents included in the spirit of the present invention defined by the claims. Therefore, the present invention should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present invention.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Cylinder block 14 Combustion chamber 16 Cylinder 18 Piston 20 Intake manifold 22 Surge tank 24 Intake pipe 26 Air cleaner 28 Throttle valve 30 Exhaust manifold 32 Exhaust pipe 34 Pre-stage catalyst device 36 Rear-stage catalyst device 40 Spark plug 42 Injector 54 Crank angle sensor 56 In-cylinder pressure sensor Vi Intake valve Ve Exhaust valve

Claims (4)

A control device for an internal combustion engine configured to control exhaust energy,
When the difference between the target exhaust energy and the actual exhaust energy is equal to or greater than a predetermined amount, the response of the plurality of control parameters is obtained from a plurality of combinations of values of the plurality of control parameters of the internal combustion engine having the possibility of realizing the target exhaust energy. A selection means for selecting one combination in consideration;
Control means for controlling the internal combustion engine based on one combination of the values of the plurality of control parameters selected by the selection means ,
The selection means includes
For each combination of a plurality of combinations of the values of the plurality of control parameters, an aerial distance value calculating means for calculating an aerial distance value considering the responsiveness of the plurality of control parameters;
Minimum value selection means for selecting a minimum value from a plurality of overhead distance values calculated by the overhead distance value calculation means;
Corresponding to the smallest imaginary distance value selected by the outermost minimum value selecting means, one combination of values of said plurality of control parameters, Ru and a determining means for determining one of the combination adapted to the target exhaust energy A control device for an internal combustion engine. The selection means includes
Correlation data between exhaust energy and the plurality of control parameters stored in a storage device;
Actual exhaust energy calculating means for calculating actual exhaust energy in the exhaust system of the internal combustion engine;
Target exhaust energy calculating means for calculating target exhaust energy in the exhaust system of the internal combustion engine;
When the difference between the actual exhaust energy calculated by the actual exhaust energy calculating means and the target exhaust energy calculated by the target exhaust energy calculating means is a predetermined amount or more, the correlation data is searched based on the target exhaust energy. Te, the control apparatus for an internal combustion engine according to claim 1, characterized in that it comprises a plurality combination selection means for selecting a plurality of combinations of values of the plurality of control parameters. The exhaust energy, the control device for an internal combustion engine according to claim 1 or 2, characterized in that the heat quantity of the exhaust gas. 3. The control apparatus for an internal combustion engine according to claim 2 , further comprising data update means for updating the correlation data using actual exhaust energy detected or estimated by the actual exhaust energy detection means.

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