JP2016205209A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, in which the control value of an actuator owned by an internal combustion engine is determined by applying a parameter relating to the operation state of the internal combustion engine, and in which the change of the control value is repeated for a short time period when a parameter value varies in the vicinity of a control value change threshold value or a parameter value, at which the control value changes.SOLUTION: In a control device for an internal combustion engine according to the invention, a control value is acquired by applying representative values individually corresponding to a plurality of parameter value ranges obtained by dividing the ranges of a value which can be acquired by a parameter, and the upper limit value or the lower limit value of a parameter value range is adjusted, when it is decided whether or not the current value of the parameter is contained by the parameter value range in which the parameter has been contained.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for an internal combustion engine that determines a control value of an actuator provided in the engine according to a parameter relating to an operating state of the internal combustion engine (hereinafter also simply referred to as “engine”).

  2. Description of the Related Art A valve characteristic control device for an internal combustion engine is known that includes a variable valve lift mechanism that can change the maximum lift amount and operating angle of an intake valve, and a variable valve timing mechanism that can change the opening / closing timing of the intake valve (for example, , See Patent Document 1).

  This type of engine control device (hereinafter also referred to as “conventional device”) changes the working angle of the intake valve and the maximum lift in a stepwise manner in accordance with changes in the operating state of the engine. Thus, the fuel consumption, output, exhaust gas characteristics, etc. of the engine can be improved. Conventional devices often store a pre-adapted map (look-up table) and apply parameters related to engine operating conditions (eg, engine speed and / or air flow) to this map. Is employed to determine the operating angle and the opening / closing timing (that is, the control value of the actuator provided in the engine).

JP 2006-266200 A

  For example, when the operating angle of the intake valve is controlled to change stepwise based on the map, the operating angle is changed when the parameter value changes beyond a specific threshold. A parameter value at which the control value of the actuator is switched like this specific threshold value is also referred to as a “control value change threshold value”.

  When the operating angle of the intake valve is controlled to change stepwise, the amount of change when the operating angle is changed is larger than when the operating angle is controlled to change continuously. For this reason, when the parameter value fluctuates in the vicinity of the control value change threshold, there may occur an event in which the operating angle changes relatively large and then returns to the original operating angle in a short time. As a result, if the engine controlled by the conventional device is mounted on the vehicle, the vehicle occupant may feel uncomfortable.

  Therefore, one of the objects of the present invention is an internal combustion engine that can suppress the occurrence of an event in which the change of the actuator control value is repeated in a short time even if the parameter value fluctuates in the vicinity of the control value change threshold. It is to provide a control device.

  In order to achieve the above object, a control device for an internal combustion engine of the present invention (hereinafter also referred to as “the present invention device”) includes a representative value output unit and a map application unit, and includes parameters relating to the operating state of the internal combustion engine. In response, the control value of the actuator provided in the engine is determined.

The representative value output unit includes:
A value included in each of a plurality of parameter value ranges obtained by dividing a range of possible values of the parameter, out of representative values predetermined for each of the parameter value ranges, The representative value output process of outputting the selected representative value that is the representative value for the selected parameter value range that is the parameter value range including the current value to the map application unit is repeatedly executed.

Further, the representative value output unit includes:
When the representative value output process is executed, a lower limit correction process and / or an upper limit correction process is executed.
The lower limit correction process is:
The current value of the parameter is smaller than the lower limit value of the previous parameter value range that is the selected parameter value range selected when the representative value output process was executed last time, and between the current value and the lower limit value. If the magnitude of the difference is smaller than a first predetermined value, the parameter value range that is the same as the previous parameter value range is selected as the selection parameter value range, and the selected representative value is the value corresponding to the previous parameter value range. This is control for outputting the same value as the representative value to the map application unit.

On the other hand, the upper limit correction process is:
If the current value of the parameter is larger than the upper limit value of the previous parameter value range and the difference between the current value and the upper limit value is smaller than a second predetermined value, the selected parameter value range is the same as the previous parameter value range. In this control, the parameter value range that is the same as the parameter value range is selected, and the same value as the representative value for the previous parameter value range is output to the map application unit as the selected representative value.

The map application unit
Holding a map containing a set of combinations of each of the representative values and the control value pre-adapted to each of the representative values;
The control value is determined by applying the selected representative value output by the representative value output unit to the map.

  For example, when it is determined whether or not the parameter value is included in the previous parameter value range, the lower limit correction process is executed by making the lower limit value of the parameter value range smaller than the original lower limit value by a predetermined value. . The parameter value range is acquired by dividing the range of possible values of the parameter (in this example, the air flow rate Ga) as shown in the flow value range (b1) to the flow value range (b3) in FIG. The

  In the example of FIG. 5, as indicated by points p2 and p3, the air flow rate Ga increases beyond the flow rate threshold value g2 that is the control value change threshold value, and as a result, the air flow rate Ga falls within the flow rate value range (b3). When it is included, the control value is changed. On the other hand, as shown by points p4 and p5, when the air flow rate Ga decreases beyond the flow rate threshold value g2, whether or not the air flow rate Ga is included in the flow rate value range (b3) which is the previous parameter value range. In the determination, the flow rate threshold value g2m is applied as the lower limit value instead of the flow rate threshold value g2. Since the air flow rate Ga corresponding to the point p5 is larger than the flow rate threshold value g2m, it is determined that the air flow rate Ga corresponding to the point p5 is included in the quantity value range (b3).

  That is, after the air flow rate Ga increases from the lower limit value (flow rate threshold value g2) of the flow rate value range (b3) and is included in the flow rate value range (b3), the air flow rate Ga continues to be in the flow rate value range (b3). ) Is applied with a lower limit value (flow rate threshold value g2m) lower than the flow rate threshold value g2. As a result, even if the air flow rate Ga fluctuates in the vicinity of the original lower limit value (flow rate threshold value g2) (for example, points p3 to p9 in FIG. 5), the air flow rate Ga is included in the flow rate value range (b3). It continues to be determined that

  Therefore, according to the device of the present invention, it is possible to suppress the occurrence of an event in which the change of the actuator control value is repeated in a short time even if the parameter value fluctuates in the vicinity of the control value change threshold.

1 is a schematic view of an internal combustion engine (main engine) to which an internal combustion engine control apparatus (main control apparatus) according to an embodiment of the present invention is applied. It is the graph showing a mode that the opening / closing timing and working angle of the intake valve of this engine are changed by the variable valve timing mechanism and variable valve lift mechanism with which this engine is equipped. It is a graph showing the operating angle determined according to the operating state of this engine. It is a map for determining the working angle which this control apparatus has memorize | stored. It is a time chart showing a mode that an air flow rate changes with time. It is a flowchart showing the map input value determination process which this control apparatus performs.

(Constitution)
Hereinafter, an internal combustion engine control apparatus according to an embodiment of the present invention will be described with reference to the drawings. A control device for an internal combustion engine according to an embodiment of the present invention (hereinafter also referred to as “the present control device”) is applied to the internal combustion engine 10 shown in FIG. The engine 10 is mounted on a vehicle (not shown). The engine 10 is a four-cycle spark ignition internal combustion engine that uses gasoline as fuel. The engine 10 shown in FIG. 1 is a multi-cylinder internal combustion engine having four combustion chambers, that is, four cylinders. FIG. 1 shows the configuration of only one specific cylinder. However, the remaining cylinders have the same configuration.

The engine 10 includes a cylinder block portion 20, a cylinder head portion 30, an intake system 60, and an exhaust system 70.
The cylinder block unit 20 includes a cylinder 21, a piston 22, a connecting rod 23 and a crankshaft 24. The piston 22 reciprocates in the cylinder 21, and the reciprocating motion of the piston 22 is transmitted to the crankshaft 24 via the connecting rod 23, whereby the crankshaft 24 rotates. A combustion chamber 25 is formed by the cylinder 21, the crown surface of the piston 22, and the cylinder head portion 30.

  The cylinder head portion 30 includes an intake port 31 communicating with the combustion chamber 25, an intake valve 32 that opens and closes the intake port 31, an intake rocker arm 33 that pushes down the intake valve 32, and an intake valve opening and closing device 34 that pushes down the intake rocker arm 33. Yes. Further, the cylinder head portion 30 includes an exhaust port 35 communicating with the combustion chamber 25, an exhaust valve 36 for opening and closing the exhaust port 35, an exhaust camshaft 37 for causing the exhaust valve 36 to open and close, and an exhaust rocker arm 38. It is out. Further, the cylinder head portion 30 includes a spark plug 39 that ignites the air-fuel mixture by generating a spark in the air-fuel mixture in the combustion chamber 25.

The intake valve opening / closing device 34 includes a variable valve timing mechanism 40 that changes the opening / closing timing of the intake valve 32 and a variable valve lift mechanism 50 that changes the maximum lift amount and operating angle when the intake valve 32 is opened.
The variable valve timing mechanism 40 includes an intake cam shaft 41 that drives the intake valve 32, an intake cam 42, and a hydraulic control actuator 43.

  The intake camshaft 41 is rotated once while the crankshaft 24 rotates twice by a timing belt (not shown). The intake cam 42 rotates together with the intake cam shaft 41, and can push down an input arm 52 (to be described later) by a protrusion provided in the intake cam 42.

  The variable valve timing mechanism 40 can change the rotation position (rotation phase) of the intake cam 42 with respect to the intake cam shaft 41 by the operation of the hydraulic control actuator 43. The timing at which the input arm 52 is pushed down is changed by changing the rotational position of the intake cam 42 with respect to the intake camshaft 41, so that the valve opening timing IVO and the valve closing timing IVC of the intake valve 32 are advanced or retarded. Change to the side.

  The variable valve lift mechanism 50 includes a drive shaft 51, an input arm 52 and a swing cam 53 that are fixed to be rotatable about the drive shaft 51, and an electric control actuator 54. When the roller portion included in the input arm 52 is pushed down by the intake cam 42, the drive shaft 51 rotates, so that the intake cam 32 is pushed down by the swing cam 53 pushing down the intake rocker arm 33. As a result, the intake port 31 and the combustion chamber 25 communicate with each other.

  The variable valve lift mechanism 50 can change the phase difference (rotational position difference) between the input arm 52 and the swing cam 53 with respect to the drive shaft 51 by the operation of the electric control actuator 54. When the phase difference between the input arm 52 and the swing cam 53 with respect to the drive shaft 51 is changed, the lift amount of the intake valve 32 generated when the swing cam 53 pushes down the intake rocker arm 33 is changed. The maximum lift amount Lmax and the working angle VCAM of the valve 32 are changed.

The intake system 60 includes an intake pipe 61 communicated with the combustion chamber 25 via the intake port 31, a throttle valve 62 (intake throttle valve) capable of changing the opening area (open sectional area) of the intake pipe 61, which will be described later. A throttle valve actuator 63 that rotationally drives the throttle valve 62 in response to an instruction from the ECU 80 and a fuel injection valve 64 that injects fuel toward the intake port 31 are included.
The exhaust system 70 includes an exhaust pipe 71 communicated with the combustion chamber 25 via the exhaust port 35.

  The ECU 80 is an electronic control unit (ECU) for controlling the engine 10. The ECU 80 includes a CPU 81, a ROM 82 that stores a program executed by the CPU 81, a map (lookup table), and the like in advance, and a RAM 83 that the CPU 81 temporarily stores data as necessary. The control for the variable valve timing mechanism 40 (specifically, the hydraulic control actuator 43) and the variable valve lift mechanism 50 (specifically, the electric control actuator 54) executed by the ECU 80 is executed in common for all cylinders included in the engine 10. Is done. The ECU 80 is connected to sensors described below.

  The air flow meter 91 measures the mass flow rate (air flow rate) of the inflow air passing through the intake pipe 61 and outputs a signal representing the air flow rate Ga. The crank angle sensor 92 measures the rotational position of the crankshaft 24 and outputs a signal representing the crank angle CA. The ECU 80 calculates the engine speed NE of the engine 10 based on the crank angle CA.

(Operation mode of intake valve 32)
Next, control of the variable valve timing mechanism 40 and the variable valve lift mechanism 50 by the ECU 80 will be described. FIG. 2 is a graph showing the lift amount Lv of the exhaust valve 36 and the intake valve 32 with respect to the crank angle CA. The period from the valve opening timing IVO to the valve closing timing IVC is also referred to as a working angle VCAM. As the maximum lift amount Lmax increases, the operating angle VCAM increases.

  The ECU 80 controls the variable valve lift mechanism 50 to switch the maximum lift amount Lmax among the maximum lift amount Lmax1, the maximum lift amount Lmax2, and the maximum lift amount Lmax3. In other words, the ECU 80 switches the working angle VCAM between the working angle VCAM1 corresponding to the maximum lift amount Lmax1, the working angle VCAM2 corresponding to the maximum lift amount Lmax2, and the working angle VCAM3 corresponding to the maximum lift amount Lmax3. The working angle VCAM increases from the working angle VCAM1 through the working angle VCAM2 to the working angle VCAM3 (that is, VCAM1 <VCAM2 <VCAM3).

  In addition, the ECU 80 changes the valve opening timing IVO and the valve closing timing IVC by controlling the variable valve timing mechanism 40 when switching the operating angle VCAM. More specifically, when the operating angle VCAM is the operating angle VCAM1, the valve opening timing IVO is the crank angle IVO1, and the valve closing timing IVC is the crank angle IVC1. When the operating angle VCAM is the operating angle VCAM2, the valve opening timing IVO is the crank angle IVO2, and the valve closing timing IVC is the crank angle IVC2. When the operating angle VCAM is the operating angle VCAM3, the valve opening timing IVO is the crank angle IVO3, and the valve closing timing IVC is the crank angle IVC3.

  In other words, the ECU 80 switches the combination of the valve opening timing IVO and the valve closing timing IVC of the intake valve 32 and the operating angle VCAM (the operation mode of the intake valve 32) between the curves Ci1 to Ci3. Hereinafter, the working angle VCAM (any of the working angle VCAM1 to the working angle VCAM3) is used as an index value representing the operation mode of the intake valve 32.

(Selection of working angle VCAM)
The ECU 80 selects the working angle VCAM based on the rotational speed NE and the air flow rate Ga. The relationship among the rotational speed NE, the air flow rate Ga, and the working angle VCAM is shown in FIG. When the combination of the rotational speed NE and the air flow rate Ga (hereinafter also referred to as “the operating state of the engine 10”) is in the region A1 in FIG. 3, the ECU 80 selects the working angle VCAM1 as the working angle VCAM. When the operating state of the engine 10 is in the region A2 in FIG. 3, the ECU 80 selects the working angle VCAM2 as the working angle VCAM. When the operating state of the engine 10 is in the region A3 of FIG. 3, the ECU 80 selects the operating angle VCAM3 as the operating angle VCAM.

  In other words, the ECU 80 has a magnitude relationship between the speed threshold value n1 and the speed threshold value n2 that define each of the areas A1 to A3, the flow rate threshold value g1 and the flow rate threshold value g2, and the rotational speed NE and the air flow rate Ga. Based on the above, the working angle VCAM is determined.

  Parameter values at which the control value represented by the operating angle VCAM is switched, such as the speed threshold value n1, the speed threshold value n2, the flow rate threshold value g1, and the flow rate threshold value g2, are also referred to as control value change threshold values. It can be said that the control value change threshold is a parameter value that demarcates the boundaries of “regions representing a set of operating states having the same control value” such as the regions A1 to A3.

  However, when the ECU 80 determines the operating angle VCAM, the speed threshold value n1m may be used instead of the speed threshold value n1 as the lower limit value of the rotational speed NE that defines the region A2. Alternatively, the speed threshold value n2m may be used instead of “speed threshold value n2 larger than the speed threshold value n1 (ie, n1 <n2)” as the lower limit value of the rotational speed NE that defines the region A3.

  Similarly, the flow rate threshold value g1m may be used instead of the flow rate threshold value g1 as the lower limit value of the air flow rate Ga that defines the region A2. In addition, the flow rate threshold value g2m may be used instead of “flow rate threshold value g2 larger than the flow rate threshold value g1 (that is, g1 <g2)” as the lower limit value of the air flow rate Ga that defines the region A3.

  Each of the speed threshold value n1m and the speed threshold value n2m is a value smaller than each of the speed threshold value n1 and the speed threshold value n2 by a predetermined value Hn (that is, n1m = n1-Hn, n2m = n2-Hn). On the other hand, each of the flow rate threshold value g1m and the flow rate threshold value g2m is smaller than the flow rate threshold value g1 and the flow rate threshold value g2 by a predetermined value Hg (that is, g1m = g1-Hg, g2m = g2-Hg). The predetermined value Hg is also referred to as “first predetermined value” for convenience.

  The process of correcting (adjusting) the lower limit values of the areas A2 and A3 executed by the ECU 80 is also referred to as “lower limit correction process”. First, a method of selecting the working angle VCAM without the lower limit correction process will be described, and then the lower limit correction process will be described.

  The ECU 80 stores the relationship between the combination of the representative values of the rotational speed NE and the air flow rate Ga and the working angle VCAM in the form of a lookup table (map) in the ROM 82 as shown in FIG. . The ECU 80 determines the working angle VCAM by applying the representative values of the rotational speed NE and the air flow rate Ga selected by the method described later to the map of FIG.

  More specifically, when the rotational speed NE is between “0” and the speed threshold n1, the ECU 80 selects “0” as the representative value of the rotational speed NE. In addition, when the rotational speed NE is between the speed threshold value n1 and the speed threshold value n2, the ECU 80 selects the speed threshold value n1 as a representative value of the rotational speed NE. Further, when the rotational speed NE is larger than the speed threshold value n2, the ECU 80 selects the speed threshold value n2 as a representative value of the rotational speed NE.

  Similarly, when the air flow rate Ga is between “0” and the flow rate threshold value g1, the ECU 80 selects “0” as the representative value of the air flow rate Ga. In addition, when the air flow rate Ga is between the flow rate threshold value g1 and the flow rate threshold value g2, the ECU 80 selects the flow rate threshold value g1 as a representative value of the air flow rate Ga. Further, when the air flow rate Ga is larger than the flow rate threshold value g2, the ECU 80 selects the flow rate threshold value g2 as a representative value of the air flow rate Ga.

In other words, when the ECU 80 selects the representative value of the rotational speed NE, the current value of the rotational speed NE is a speed value range obtained by dividing the range of values that the rotational speed NE can take into three, that is,
(A1) Between “0” and the speed threshold n1,
(A2) Between the speed threshold n1 and the speed threshold n2, and
(A3) From the speed threshold value n2 to the maximum value of the rotational speed NE,
It is determined which of these is included. Further, the ECU 80 includes “0”, which is a representative value of each of the speed value range (a1) to the speed value range (a3), a speed value that includes the current value of the rotational speed NE among the speed threshold value n1 and the speed threshold value n2. The representative value corresponding to the range is selected as one of the values applied to the map of FIG.

Similarly, when the ECU 80 selects a representative value of the air flow rate Ga, the current value of the air flow rate Ga is a flow rate value range obtained by dividing a range of values that the air flow rate Ga can take, that is,
(B1) Between “0” and the flow rate threshold value g1,
(B2) Between the flow rate threshold value g1 and the flow rate threshold value g2, and
(B3) Between the flow rate threshold value g2 and the maximum value of the air flow rate Ga,
It is determined which of these is included. Further, the ECU 80 sets “0”, which is a representative value of each of the flow rate value range (b1) to the flow rate value range (b3), a flow rate value including a current value of the air flow rate Ga among the flow rate threshold value g1 and the flow rate threshold value g2. The representative value corresponding to the range is selected as the other value to which the map of FIG. 4 is applied.

  The speed value range including the current value of the rotational speed NE and the flow value range including the current value of the air flow rate Ga are also referred to as a selection parameter value range. Hereinafter, the representative value of the flow value range (b1) is Gath (1) (ie, Gath (1) = 0), and the representative value of the flow value range (b2) is Gath (2) (ie, Gath (2) = g1). ) And the representative value of the flow rate value range (b3) are also expressed as Gath (3) (that is, Gath (3) = g2).

(Lower limit correction process)
However, if the ECU 80 determines the working angle VCAM while referring to the map of FIG. 4, an event that the working angle VCAM is frequently switched may occur. For example, in FIG. 5 showing an example of a change in the air flow rate Ga in a state where the rotational speed NE is higher than the speed threshold value n2, the air flow rate Ga fluctuates in the vicinity of the flow rate threshold value g2 as represented by the points p1 to p7. Then, the working angle VCAM interchanges between the working angle VCAM2 and the working angle VCAM3. As a result, the occupant of the vehicle on which the engine 10 is mounted may feel uncomfortable.

  Therefore, the ECU 80 selects the representative values of the rotational speed NE and the air flow rate Ga applied to the map of FIG. 4 in order to prevent the working angle VCAM from switching between each other in a short time. There is a case where a lower limit correction process for adjusting the parameter value range is executed.

  When the ECU 80 determines whether or not the rotational speed NE is included in the same speed value range as the “speed value range in which the rotational speed NE has been included (previous parameter value range)”, the ECU 80 Lower limit correction processing is executed by reducing the lower limit value by a predetermined value Hn. Similarly, when the ECU 80 determines whether the air flow rate Ga is included in the same flow rate value range as the “flow rate value range in which the air flow rate Ga was previously included (previous parameter value range)”, the previous parameter Lower limit correction processing is executed by reducing the lower limit value of the value range by a predetermined value Hg.

  Hereinafter, although the lower limit correction process which ECU80 performs with respect to the air flow rate Ga is demonstrated, referring FIG. 5, ECU80 performs the same lower limit correction process also with respect to rotational speed NE. In FIG. 5, for example, the fact that the air flow rate Ga changes from “the value of the air flow rate Ga represented by the point p1” to “the value of the air flow rate Ga represented by the point p2” simply means that the “air flow rate Ga is the point of FIG. "change from p1 to point p2".

  When the air flow rate Ga changes from the point p4 in FIG. 5 to the point p5, since the air flow rate Ga corresponding to the point p4 is included in the flow value range (b3), the previous parameter value range at this time is the flow value range ( b3). Therefore, when it is determined whether or not the air flow rate Ga corresponding to the point p5 is included in the flow rate value range (b3), the flow rate threshold value g2m is applied instead of the flow rate threshold value g2 as the lower limit value of the flow rate value range (b3). Is done.

  In other words, when the ECU 80 selects a representative value of the air flow rate Ga corresponding to the point p5, the flow rate threshold value g2m is used as “the upper limit value of the flow rate value range (b2) and the lower limit value of the flow rate value range (b3)”. . As a result, since the air flow rate Ga corresponding to the point p5 is larger than the flow rate threshold value g2m, the ECU 80 determines that the point p5 is included in the flow rate value range (b3), and thus the representative value of the air flow rate Ga is the flow rate threshold value. g2. That is, when the air flow rate Ga changes from the point p4 to the point p5, the working angle VCAM is maintained at the working angle VCAM3.

  In addition, when the air flow rate Ga changes from the point p7 to the point p8, since the previous parameter value range is the flow value range (b3), the flow rate threshold value g2m is used as the lower limit value of the flow value range (b3). Therefore, the representative value of the air flow rate Ga is the flow rate threshold value g2. Therefore, the working angle VCAM is maintained at the working angle VCAM3 from the point p3 to the point p9.

  Thereafter, when the air flow rate Ga changes from the point p9 to the point p10, the air flow rate Ga corresponding to the point p10 is smaller than the flow rate threshold value g2m (and larger than the flow rate threshold value g1), so that the working angle VCAM acts from the working angle VCAM3. Changed to corner VCAM2.

  On the other hand, when the air flow rate Ga changes from the point p13 to the point p14, the previous parameter value range at this point is the flow rate value range (b2) including the air flow rate Ga corresponding to the point p13. ), The flow rate threshold value g1m is applied instead of the flow rate threshold value g1. In other words, since the flow rate threshold value g2 is applied as the lower limit value of the flow rate value range (b3), the working angle VCAM is changed from the working angle VCAM2 to the working angle VCAM3.

  Further, when the air flow rate Ga changes from the point p18 to the point p19, the previous parameter value range at this point is the flow rate value range (b3) including the air flow rate Ga corresponding to the point p18. ), The flow rate threshold value g2m is applied instead of the flow rate threshold value g2. In other words, when the selection parameter value range corresponding to the point p19 is selected, the flow rate threshold value g1 is applied as a lower limit value of the flow rate value range (b2) in principle, so that the working angle VCAM is changed from the working angle VCAM3 to the working angle VCAM1. Changed to

(Specific operation)
The specific operation of the CPU 81 (hereinafter also simply referred to as “CPU”) of the ECU 80 when selecting the representative value of the air flow rate Ga to be applied to the map of FIG. 4 is shown by a flowchart in FIG. This will be described with reference to the “map input value determination processing routine”. The CPU executes this routine every time a predetermined time elapses.

  The CPU executes a routine similar to the flowchart of FIG. 6 when selecting a representative value of the rotational speed NE applied to the map of FIG. The CPU applies the map input value Gai (selected representative value) of the representative value of the air flow rate Ga determined by this routine and the representative value of the rotational speed NE determined by the routine (not shown) to the map of FIG. To determine the working angle VCAM (control value).

  That is, when the appropriate timing is reached, the CPU starts the process from step 600 and proceeds to step 605 to acquire the current value of the air flow rate Ga. Next, the CPU proceeds to step 610 to acquire “a map input value Gai related to the air flow rate Ga selected when the CPU executed this routine last time” as the previous value Gaip. When the CPU executes this routine for the first time after the operation of the engine 10 is started, the CPU sets Gath (1) (that is, “0”) as the previous value Gip in step 610.

  Next, the CPU proceeds to step 615 to set “1” as the value of the counter cnt. Next, the CPU proceeds to step 620 to determine whether or not the previous value Gaip is equal to Gath (counter cnt + 1). For example, when step 620 is executed when the value of the counter cnt is “1”, the previous value Gip is the representative value of the flow value range (b2), that is, Gath (1 + 1) = Gath (2). It is determined whether or not it is equal to the flow rate threshold value g1.

(A) When the previous value Gaip = 0 and the air flow rate Ga <flow rate threshold value g1 Now, the previous value Gaip is “0”, and the current value of the air flow rate Ga is between “0” and the flow rate threshold value g1. Suppose that For example, the point p22 in FIG. 5 corresponds to this situation.

  In this case, when step 620 is executed after step 615 (that is, when the counter cnt = 1), it is determined whether or not the previous value Gaip is equal to Gath (1 + 1) = Gath (2). The Since the previous value Gip is “0”, the two values are not equal (specifically, the previous value Gip = 0 <Gath (2) = flow rate threshold value g1). Therefore, the CPU makes a “No” determination at step 620 to proceed to step 645 to set Gath (cnt + 1) (in this case, Gath (2)) as the value of the comparison value comp.

  Next, the CPU proceeds to step 630 to determine whether or not the air flow rate Ga is smaller than the comparison value comp. According to the above assumption, since the air flow rate Ga is smaller than the flow rate threshold value g1, the CPU makes a “Yes” determination at step 630 to proceed to step 635, where Gath (cnt) (this is the map input value Gai) In this case, Gath (1) = 0) is set (that is, the map input value Gai = 0). Next, the CPU proceeds to step 695 to end the present routine tentatively.

(B) When previous value Gaip = 0 and flow rate threshold value g1 <air flow rate Ga <flow rate threshold value g2 Then, it is assumed that air flow rate Ga increases and is between flow rate threshold value g1 and flow rate threshold value g2. For example, the point p23 in FIG. 5 corresponds to this situation.

  In this case, when step 620 is executed after step 615 (that is, when the counter cnt = 1), the CPU makes a “No” determination at step 620 to proceed to step 645 to determine the value of the comparison value comp. Is set to the flow rate threshold value g1, and then the process proceeds to Step 630. According to the above assumption, since the air flow rate Ga is larger than the comparison value comp (ie, the flow rate threshold value g1), the CPU makes a “No” determination at step 630 to proceed to step 650, and the counter cnt reaches the counter upper limit. It is determined whether or not it is equal to the value cntMax (in this example, cntMax = 2).

  At this time, since the value of the counter cnt is “1”, the CPU makes a “No” determination at step 650 to proceed to step 640 to increase the value of the counter cnt by “1”. That is, the value of the counter cnt is “2”. Next, the CPU proceeds to step 620. Since the previous value Gaip is smaller than Gath (cnt + 1) (ie, Gath (3) = flow rate threshold value g2), the CPU makes a “No” determination at step 620 to proceed to step 630 via step 645.

  According to the above assumption, since the air flow rate Ga is smaller than the comparison value comp (in this case, Gath (3) = flow rate threshold value g2), the CPU makes a “Yes” determination at step 630 to proceed to step 635. Then, the value of the map input value Gai is set to Gath (2) (that is, the flow rate threshold value g1). Next, the CPU proceeds to step 695. That is, in this case, the CPU changes the value of the map input value Gai from “0” to the flow rate threshold value g1.

(C) When previous value Gip = g1 and flow rate threshold value g2 <air flow rate Ga It is assumed that the air flow rate Ga further increases and is between the flow rate threshold value g1 and the flow rate threshold value g2. For example, the point p3 in FIG. 5 corresponds to this situation.

  In this case, when step 620 is executed after step 615 (that is, when counter cnt = 1), since Gath (cnt + 1) = flow rate threshold value g1, the CPU makes a “Yes” determination at step 620. Then, the process proceeds to step 625. In step 625, the CPU sets the comparison value comp to a value that is smaller than Gath (cnt + 1) by a predetermined value Hg (ie, comp = Gath (cnt + 1) −Hg).

  In this case, since the value of the counter cnt is “1”, the comparison value comp is “flow rate threshold value g1−predetermined value Hg”. That is, when it is determined whether or not the air flow rate Ga is included in the “flow value range in which the air flow rate Ga has been included (previous parameter value range)” represented by the previous value Gaip, The lower limit value of the range is set to a value that is smaller by a predetermined value Hg. That is, the CPU executes a lower limit correction process.

  Next, the CPU proceeds to step 630. According to the above assumption, since the air flow rate Ga is larger than the flow rate threshold value g2, the CPU makes a “No” determination at step 630, and after step 650 and step 640, the value of the counter cnt is “2”. Then proceed again. In this case, the CPU makes a “No” determination at step 620 to set the value of the comparison value comp at Gath (3) (ie, the flow rate threshold value g2) at step 645 and then proceeds to step 630. In step 630, the CPU again determines “No” and proceeds to step 650.

  In this case, since the value of the counter cnt is “2”, the CPU makes a “Yes” determination at step 650 to proceed to step 655 to set the value of the map input value Gai to Gath (3) (that is, the flow rate threshold value). Set to g2). Next, the CPU proceeds to step 695. That is, in this case, the CPU changes the map input value Gai from the flow rate threshold value g1 to the flow rate threshold value g2.

(D) When previous value Gip = g2 and flow rate threshold value g2-predetermined value Hg <air flow rate Ga <flow rate threshold value g2 Previous parameter value range in which air flow rate Ga is represented by previous value Gaip (in this case, flow rate value) It is assumed that the range (b3)) is smaller than the lower limit value (in this case, the flow rate threshold value g2) and that the difference between the air flow rate Ga and the lower limit value is smaller than the predetermined value Hg. For example, the point p5 in FIG. 5 corresponds to this situation.

  In this case, when the CPU executes step 620 when the value of the counter cnt is “2”, it determines “Yes” in step 620 and proceeds to step 625. In step 625, the CPU sets the value of the comparison value comp to a value (that is, the flow rate threshold value g2−the predetermined value Hg) that is smaller by a predetermined value Hg than Gath (3) (that is, the flow rate threshold value g2). Next, the CPU proceeds to step 630.

  According to the above assumption, since the air flow rate Ga is larger than the comparison value comp, the CPU makes a “No” determination at step 630 to execute steps 650 and 655. That is, in this case, the air flow rate Ga is smaller than the flow rate threshold value g2, but the value of the map input value Gai is maintained at the same flow rate threshold value g2 as the previous value Gaip.

(E) When previous value Gaip = g2 and flow rate threshold value g1 <air flow rate Ga <flow rate threshold value g2-predetermined value Hg The air flow rate Ga is smaller than the lower limit value of the previous parameter value range represented by the previous value Gaip. Furthermore, it is assumed that the magnitude of the difference between the air flow rate Ga and the lower limit value is larger than the predetermined value Hg. For example, the point p10 in FIG. 5 corresponds to this situation.

  In this case, when the CPU executes Step 620 when the value of the counter cnt is “2”, it determines “Yes” at Step 620, proceeds to Step 630 through Step 625, and proceeds to “Yes” at Step 630. Is determined. That is, the map input value Gai is changed to a flow rate threshold value g1 smaller than the previous value Gaip (in this case, the flow rate threshold value g2) in step 635.

  That is, even if the lower limit correction process is executed, if the air flow rate Ga is smaller than the corrected “lower limit value of the previous parameter value range represented by the previous value Gaip”, the value of the map input value Gai is changed.

(F) When the previous value Gip = g2 and the air flow rate Ga <flow rate threshold value g1 The air flow rate Ga is “a parameter that includes the air flow rate Ga when the air flow rate Ga is smaller than the lower limit value of the previous parameter value range. It is assumed that the value range is smaller than the “lower limit value of the parameter value range adjacent to the previous parameter value range”. For example, the point p19 in FIG. 5 corresponds to this situation.

  In this case, when step 620 is executed after step 615 (that is, when the counter cnt = 1), the CPU makes a “No” determination at step 620 to proceed to step 645 to determine the value of the comparison value comp. Is set to the flow rate threshold value g1, and then the process proceeds to Step 630.

  That is, as described above, when it is determined whether or not the air flow rate Ga is included in the previous parameter value range, the lower limit value of the previous parameter value range is set to a value that is smaller by the predetermined value Hg (corrected). However, the lower limit value of the parameter value range different from the previous parameter value range is not corrected.

As described above, this control inversion (ECU 80)
Control values (valve opening timing IVO and valve closing timing) of actuators (hydraulic control actuator 43 and electric control actuator 54) included in the engine according to parameters (rotational speed NE and air flow rate Ga) relating to the operating state of the internal combustion engine (10). A control device for an internal combustion engine for determining an IVC and an operating angle VCAM),
A representative value output unit and a map application unit are provided.
The representative value output unit includes:
A value included in each of a plurality of parameter value ranges (flow rate value range (b1) to flow rate value range (b3)) obtained by dividing a range of possible values of the parameter (air flow rate Ga) in advance. Among the representative values (input values in the map of FIG. 4) predetermined for each of the parameter value ranges, the selected parameter value range (which depends on the map input value Gai) is the parameter value range that includes the current value of the parameter. A representative value output process for outputting a selected representative value (map input value Gai) that is the representative value for the flow rate value range) to the map application unit,
Further, when the representative value output process is executed, the current value of the parameter is smaller than the lower limit value of the previous parameter value range that is the selected parameter value range selected when the representative value output process was executed last time. If the magnitude of the difference between the current value and the lower limit value is smaller than a first predetermined value (predetermined value Hg and predetermined value Hn), the same parameter as the previous parameter value range as the selected parameter value range Lower limit correction processing (step 620, step 625, step 630 in FIG. 6) and a value range is selected and the same value as the representative value for the previous parameter value range is output to the map application unit as the selected representative value. Step 635 is executed in this order) and / or the current value of the parameter is greater than the upper limit value of the previous parameter value range. If the difference between the current value and the upper limit value is smaller than a second predetermined value, the same parameter value range as the previous parameter value range is selected as the selected parameter value range, and An upper limit correction process for outputting the same value as the representative value for the previous parameter value range to the map application unit as a selected representative value;
The map application unit
Holding a map (map of FIG. 4) including a set of combinations of each of the representative values and the control value preliminarily adapted to each of the representative values;
The control value is determined by applying the selected representative value output by the representative value output unit to the map (any of the working angle VCAM1 to the working angle VCAM3 determined by the map of FIG. 4),
It is configured as follows.

  According to this control apparatus, even if the air flow rate Ga fluctuates near the flow rate threshold value g1 or the flow rate threshold value g2, it is possible to suppress the occurrence of an event in which the change of the working angle VCAM is repeated in a short time. Similarly, even if the rotational speed NE fluctuates in the vicinity of the speed threshold value n1 or the speed threshold value n2, it is possible to suppress the occurrence of an event in which the change of the working angle VCAM is repeated in a short time.

  In addition, since the lower limit correction process is executed “when it is determined whether or not the parameter value is included in the previous parameter value range”, the air flow rate Ga changes from the point p18 to the point p19 in FIG. In this case, the working angle VCAM is not maintained at the working angle VCAM3. Therefore, when the parameter value changes abruptly, the present control device can quickly change the control value.

  When the parameter value fluctuates in the vicinity of a specific value, the control value (candidate value) obtained by applying the map and the control value when applying the previous map (previous value) so that the control value does not fluctuate greatly In some cases, it is effective to adopt a value between the two as a new control value. However, in the present embodiment, since the working angle VCAM changes stepwise, when the candidate value is the working angle VCAM3 and the previous value is the working angle VCAM2, a value between the candidate value and the previous value is set. It cannot be adopted as a new control value. On the other hand, according to the present control device, even when the control value changes stepwise, it is possible to suppress the control value from fluctuating greatly due to the above-described lower limit correction process and / or upper limit correction process.

  As mentioned above, although embodiment of the control apparatus of the internal combustion engine which concerns on this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the objective of this invention.

  For example, in the present embodiment, the ECU 80 executes the lower limit correction process. However, the ECU 80 may execute the upper limit correction process instead of the lower limit correction process or together with the lower limit correction process. When the ECU 80 executes the upper limit correction process and determines whether the air flow rate Ga is included in the same flow value range as the previous parameter value range, the ECU 80 sets the upper limit value of the flow value range to a predetermined value (second predetermined value). Value).

  In addition, in the present embodiment, the map of FIG. 4 is configured such that the working angle VCAM changes from the working angle VCAM1 to the working angle VCAM3 through the working angle VCAM2 as the rotational speed NE increases. Similarly, the map of FIG. 4 is configured such that the working angle VCAM changes from the working angle VCAM1 to the working angle VCAM3 through the working angle VCAM2 as the air flow rate Ga increases. However, the map referred to for determining the working angle VCAM may have a more complicated configuration than the map of the map of FIG. For example, when the rotational speed NE increases, the working angle VCAM changes directly from the working angle VCAM1 to the working angle VCAM3, and when the rotational speed NE further increases, the working angle VCAM changes from the working angle VCAM3 to the working angle VCAM2, Thereafter, the operating angle VCAM3 may be changed.

  In addition, in the present embodiment, the predetermined value when the previous parameter value range is the speed value range (a2) and the predetermined value when the previous parameter value range is the speed value range (a3) are both predetermined values. Hn. However, these predetermined values may be different from each other. Similarly, in the present embodiment, the predetermined value when the previous parameter value range is the flow value range (b2) and the predetermined value when the previous parameter value range is the flow value range (b3) are both predetermined values. Hg. However, these predetermined values may be different from each other.

  In addition, in the present embodiment, each representative value is a lower limit value of a parameter value range (corresponding parameter value range) to which each representative value corresponds. However, each representative value may be a value different from each lower limit value of the corresponding parameter value range. For example, each of the representative values may be the upper limit value of each of the corresponding parameter value ranges or “an average value of the upper limit value and the lower limit value”.

  In addition, in the present embodiment, the parameters are the rotational speed NE and the air flow rate Ga, and the control values are values related to the control of the variable valve timing mechanism 40 and the variable valve lift mechanism 50. However, each of the parameter and the control value may be a value different from these values. For example, the parameter may be a vehicle speed and an operation amount of an accelerator pedal provided in the vehicle, and the control value may be a value related to the amount of fuel injected from the fuel injection valve 64.

  Internal combustion engine ... 10, variable valve timing mechanism ... 40, hydraulic control actuator ... 43, variable valve lift mechanism ... 50, electric control actuator ... 54, ECU ... 80.

Claims (1)

A control device for an internal combustion engine that determines a control value of an actuator provided in the engine according to a parameter relating to an operating state of the internal combustion engine,
A representative value output unit and a map application unit are provided.
The representative value output unit includes:
A value included in each of a plurality of parameter value ranges obtained by dividing a range of possible values of the parameter, out of representative values predetermined for each of the parameter value ranges, Repeatedly executing representative value output processing for outputting the selected representative value that is the representative value for the selected parameter value range that is the parameter value range that includes the current value to the map application unit;
Further, when the representative value output process is executed, the current value of the parameter is smaller than the lower limit value of the previous parameter value range that is the selected parameter value range selected when the representative value output process was executed last time. And if the magnitude of the difference between the current value and the lower limit value is smaller than a first predetermined value, the parameter value range that is the same as the previous parameter value range is selected as the selection parameter value range, and the Lower limit correction processing for outputting the same value as the representative value for the previous parameter value range as the selected representative value to the map application unit, and / or the current value of the parameter is higher than the upper limit value of the previous parameter value range If the difference between the current value and the upper limit is smaller than the second predetermined value, the selected parameter value range is the same as the previous parameter value range. Wherein selecting a parameter value range, and performs the limit modification process, to be outputted to the map application unit the same value as the representative value for the previous parameter value range as the selected representative values,
The map application unit
Holding a map containing a set of combinations of each of the representative values and the control value pre-adapted to each of the representative values;
Determining the control value by applying the selected representative value output by the representative value output unit to the map;
A control device for an internal combustion engine configured as described above.

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