JP2009085139A - Control device of variable valve train - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device stabilizing the control responsiveness of a variable valve train. <P>SOLUTION: This control device makes the variable valve train (operating angle-lift variable mechanism) respond with specified response characteristics to absorb the deviation between a reference response value and an actual response value by feedback control. When the deviation Δθ<SB>TM</SB>between the target value θ<SB>T</SB>and the reference response value θ<SB>M</SB>is larger than a predetermined value Δθ0, and the calculated value of an operating amount (drive voltage V) exceeds a drive power supply voltage V0, integration calculation is stopped. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a variable valve mechanism that makes variable the operating characteristics of intake / exhaust valves (engine valves) of an internal combustion engine, such as lift amount (or / and operating angle) and valve timing.

Patent Document 1 discloses that control using a reference model of response characteristics is performed in a variable valve mechanism (variable valve timing mechanism) that changes valve timing.
This sets a prescribed response characteristic (reference model) for the target value of the variable valve mechanism, and sets the feedforward operation amount so that the response of the variable valve mechanism follows the reference model response, Based on the deviation, PID, etc., so as to eliminate the deviation between the response value in the reference model (reference response value) and the actual response value of the variable valve mechanism caused by the variation of the variable valve mechanism over time and variations due to operating conditions Is used to set the feedback operation amount, and control is performed based on the feedforward operation amount and the feedback operation amount.
JP 2003-336528 A

By the way, as in Patent Document 1, normally, since integral calculation is always performed in the feedback manipulated variable, the following problems occur.
In the transient state after the change of the target value of the variable valve mechanism, the deviation between the normative response value and the actual response value often includes factors other than variations due to changes over time of the variable valve mechanism and operating conditions. If the integral operation is performed on the above, the integral value becomes excessive, and after approaching the target value, an overshoot occurs and the convergence is delayed. For this reason, if the gain of the integral element is kept small, convergence when a large variation occurs is delayed.

  In addition, the calculated value of the manipulated variable exceeds the drive capacity (maximum drive amount) of the variable valve mechanism due to some cause, for example, an increase in friction of the variable valve mechanism at extremely low temperatures. Even if the operation does not work, if the integral calculation is performed, the integral value becomes excessive, causing an overshoot, resulting in a delay in convergence, and thus reducing the engine performance.

  The present invention has been made paying attention to such a conventional problem, and in the control of the variable valve mechanism that responds with the reference model, the feedback operation amount is calculated based on the deviation between the reference response value and the actual response value. It is an object of the present invention to improve the engine performance by improving the convergence to the target value by stopping the integral calculation under the predetermined conditions.

For this reason, the invention according to claim 1
A variable valve mechanism for changing a valve opening characteristic of the engine valve; target value calculating means for calculating a target value of the variable valve mechanism corresponding to a target value of the valve opening characteristic of the engine valve; and the variable valve valve A reference response value calculating means for calculating a reference response value when the mechanism is caused to respond with a specified response characteristic; and a feed for calculating a feedforward operation amount for causing the variable valve mechanism to respond with a specified response characteristic. A forward operation amount calculating means; a feedback operation amount calculating means for calculating a feedback operation amount for eliminating a deviation between the reference response value and the actual response value of the variable valve mechanism; the feedforward operation amount and the feedback operation; And an operation amount calculation means for calculating an operation amount output to the drive means of the variable valve mechanism based on the amount of the control valve. In,
Deviation calculating means for calculating a deviation between the target value of the variable valve mechanism and the reference response value;
An integral calculation stop means for stopping calculation by an integral element when calculating the feedback manipulated variable when the deviation between the target value of the variable valve mechanism and the reference response value is a predetermined value or more;
It is characterized by including.

  In the transient state after the change of the target value of the variable valve mechanism, the deviation between the normative response value and the actual response value often includes factors other than variations due to changes over time of the variable valve mechanism and operating conditions. If the integral operation is performed on the above, the integral value becomes excessive, and after approaching the target value, an overshoot occurs and the convergence is delayed. For this reason, if the gain of the integral element is kept small, convergence when a large variation occurs is delayed.

  In this way, in a transient state where the deviation between the target value of the variable valve mechanism and the reference response value is large, the overshoot due to an excessive integral value is caused by stopping the integral calculation in the calculation of the feedback manipulated variable. By performing the integral calculation after the deviation between the target value and the normative response value is reduced, it is possible to smoothly converge to the target value without leaving a steady deviation.

The invention according to claim 2
A variable valve mechanism similar to claim 1, a target value calculating means, a norm response value calculating means, a feedforward manipulated variable calculating means, a feedback manipulated variable calculating means, and an manipulated variable calculating means. In the control device for the variable valve mechanism,
An operation amount determination means for determining whether or not the calculated value of the operation amount output to the drive means of the variable valve mechanism is equal to or greater than the maximum drive amount of the drive means;
Integration that stops the calculation by the integral element when calculating the feedback operation amount when the calculated value of the operation amount output to the drive unit of the variable valve mechanism is equal to or greater than the maximum drive amount of the drive unit Calculation stop means;
It is characterized by including.

  In this way, when the feedback control function does not work when the calculated value of the manipulated variable is greater than or equal to the maximum drive amount of the drive means, the integral value becomes excessive by stopping the integral calculation. The overshoot due to the above can be prevented, and the integral calculation is performed after the operation amount becomes less than the maximum drive amount, whereby the target value can be smoothly converged without leaving a steady deviation.

The invention according to claim 3
The drive means is an electric actuator having an operation amount as a drive voltage, and it is determined that the calculated value of the operation amount is equal to or greater than a maximum drive amount by being equal to or greater than a power supply voltage of the electric actuator. To do.
In this way, when an electric actuator having an operation amount as a drive voltage is used as the drive means, when the calculated value of the operation amount is equal to or higher than the power supply voltage of the electric actuator, it is determined that the saturation state is equal to or greater than the maximum drive amount. Thus, the integral calculation can be stopped.

The invention according to claim 4
The drive means is an electric actuator having an operation amount as an energization duty ratio, and determines that the calculated value of the operation amount is equal to or greater than a maximum drive amount by the energization duty ratio being near 100%. And
In this way, when an electric actuator having an operation amount as the energization duty ratio is used as the driving means, when the energization duty ratio is near 100%, the calculated value of the operation amount is a saturation state equal to or greater than the maximum drive amount. It is possible to stop the integration calculation by determining.

The invention according to claim 5
The variable valve mechanism is a mechanism that varies at least one of an operating angle and a lift amount of the engine valve.
In this way, the control accuracy of the intake air amount can be improved by applying it to a variable valve mechanism that controls the intake air amount by making at least one of the operating angle and the lift amount of the engine valve variable.

The invention according to claim 6
The variable valve mechanism is a mechanism that varies the center phase of the engine valve.
In this way, the control accuracy of the intake air amount can be improved by applying it to a variable valve mechanism that controls the intake air amount by making the center phase of the engine valve variable.

Embodiments of the present invention will be described below.
FIG. 1 is a system diagram of an internal combustion engine for a vehicle according to an embodiment.
In FIG. 1, an internal combustion engine 101 is a V-type engine composed of two banks on the left and right.
An electronic control throttle 104 is interposed in the intake pipe 102 of the engine 101, and the air that has passed through the electronic control throttle 104 is distributed to each bank and then to each cylinder.

In each cylinder, air is sucked into the combustion chamber 106 via the intake valve 105.
The combustion exhaust gas is discharged from the combustion chamber 106 via the exhaust valve 107, and then exhaust gas is collected for each bank and purified by the front catalyst 108a, 108b and the rear catalyst 109a, 109b provided for each bank.
The exhausts of the banks after being purified by the rear catalysts 109a and 109b merge and flow into the muffler 103, and are then released into the atmosphere.

The exhaust valve 107 is opened and closed by a cam pivotally supported by the exhaust side camshaft 110 while maintaining a certain lift, operating angle, and valve timing (center phase of the operating angle).
On the other hand, on the intake valve 105 side, operating angle / lift variable mechanisms 112a and 112b, which are first variable valve operating mechanisms for continuously changing the lift of the intake valve 105 together with the operating angle, are provided for each bank. It is also possible to apply a variable valve mechanism that makes only one of the lift and the operating angle variable.

Further, on the intake valve 105 side, there is a second variable valve mechanism that continuously and variably controls the center phase of the operating angle of the intake valve 105 by changing the rotational phase of the intake valve drive shaft relative to the crankshaft. Center phase variable mechanisms 113a and 113b are provided for each bank.
An electronic control unit (ECU) 114 with a built-in microcomputer has the electronic control throttle 104, the operating angle / lift variable mechanisms 112a and 112b, and the center phase variable so that a target intake air amount corresponding to the accelerator opening is obtained. The mechanisms 113a and 113b are controlled.

  The electronic control unit 114 includes an air flow meter 115 (flow meter) for detecting the intake air flow rate of the engine 101, an accelerator sensor 116 for detecting the depression amount of the accelerator pedal, a crank angle sensor 117 for detecting the rotation angle of the crankshaft, Detection signals from a throttle sensor 118 that detects the opening TVO of the electronically controlled throttle 104, a water temperature sensor 119 that detects the coolant temperature of the engine 101, and air-fuel ratio sensors 111a and 111b that detect the exhaust air-fuel ratio of each bank are input. Is done.

A fuel injection valve 131 is provided at the intake port portion upstream of the intake valve 105 of each cylinder.
The fuel in the fuel tank 132 is pumped to the fuel injection valve 131 by a fuel pump 133, and the fuel injection valve 131 is driven to open by an injection pulse signal (air-fuel ratio control signal) from the electronic control unit 114. Then, an amount of fuel proportional to the injection pulse width (valve opening time) is injected into the engine 101.

Next, the structure of the operating angle / lift variable mechanisms 112a and 112b and the center phase variable mechanisms 113a and 113b will be described with reference to FIGS.
In the engine 101 of this embodiment, a pair of intake valves 105, 105 are provided for each cylinder, and an intake valve drive shaft 3 that is rotationally driven by a crankshaft is above the intake valves 105, 105 in the cylinder row direction. Is supported rotatably.

A swing cam 4 that contacts the valve lifter 2a of the intake valve 105 and opens and closes the intake valve 105 is fitted on the intake valve drive shaft 3 so as to be relatively rotatable.
Between the intake valve drive shaft 3 and the swing cam 4, operating angle / lift variable mechanisms 112a and 112b for continuously changing the operating angle and valve lift amount of the intake valve 105 are provided.

Further, at one end of the intake valve drive shaft 3, a center phase variable for continuously changing the center phase of the operation angle of the intake valve 105 by changing the rotational phase of the intake valve drive shaft 3 with respect to the crankshaft. Mechanisms 113a and 113b are provided.
As shown in FIGS. 2 and 3, the operating angle / lift variable mechanisms 112 a and 112 b are rotatable relative to the circular drive cam 11 that is fixedly provided eccentrically to the intake valve drive shaft 3. A ring-shaped link 12 that fits externally, a control shaft 13 that extends substantially parallel to the intake valve drive shaft 3 in the direction of the cylinder row, a circular control cam 14 that is fixed to the control shaft 13 in an eccentric manner, A rocker arm 15 that is externally fitted to the control cam 14 so as to be relatively rotatable, and has one end connected to the tip of the ring-shaped link 12, and a rod-shaped link 16 connected to the other end of the rocker arm 15 and the swing cam 4. ,have.

The control shaft 13 is rotationally driven within a predetermined control angle range via a gear train 18 by an electric actuator 17 (motor).
With the above configuration, when the intake valve drive shaft 3 rotates in conjunction with the crankshaft, the ring-shaped link 12 moves substantially in translation through the drive cam 11 and the rocker arm 15 swings around the axis of the control cam 14. Then, the swing cam 4 swings through the rod-shaped link 16 and the intake valve 105 is driven to open and close.

Further, by changing the rotation angle of the control shaft 13, the axial center position of the control cam 14 serving as the rocking center of the rocker arm 15 is changed, and the posture of the rocking cam 4 is changed.
As a result, the operating angle and lift of the intake valve 105 continuously increase or decrease while the center phase of the operating angle of the intake valve 105 is kept substantially constant.
FIG. 4 shows the center phase variable mechanisms 113a and 113b.

  The center phase variable mechanisms 113a and 113b are fixed to a sprocket 25 that rotates in synchronization with a crankshaft, and a first rotating body 21 that rotates integrally with the sprocket 25 and a bolt 22a of the intake valve drive shaft 3 are fixed. A second rotating body 22 fixed to one end and rotating integrally with the intake valve drive shaft 3, and a cylinder meshed with the inner peripheral surface of the first rotating body 21 and the outer peripheral surface of the second rotating body 22 by a helical spline 26. Intermediate gear 23.

The intermediate gear 23 is connected to a drum 27 via a screw 28, and a torsion spring 29 is interposed between the drum 27 and the intermediate gear 23.
The intermediate gear 23 is biased in the retarding direction (left direction in FIG. 4) by a torsion spring 29. When a voltage is applied to the electromagnetic retarder 24 to generate a magnetic force, the intermediate gear 23 advances through the drum 27 and the screw 28. It is moved in the angular direction (right direction in FIG. 4).

In accordance with the axial position of the intermediate gear 23, the relative phase of the rotating bodies 21 and 22 changes, the phase of the intake valve drive shaft 3 with respect to the crankshaft changes, and the central phase of the operating angle of the intake valve 105 continues. Changes.
The electric actuator 17 and the electromagnetic retarder 24 are driven and controlled by a control signal from the electronic control unit 114.

The structure of the center phase variable mechanisms 113a and 113b is not limited to the above-described structure, and a known mechanism that makes the rotational phase of the intake valve drive shaft 3 (intake side camshaft) variable with respect to the crankshaft is applied. Any mechanism can provide the effect of the present invention described later.
The electronic control unit 114 sets a target angle (target lift) of the control shaft 13 and feeds back an operation amount of the electric actuator 17 so that an actual angle detected by the angle sensor 32 approaches the target angle. Control.

  Further, the electronic control unit 114 performs intake air to the crankshaft from a signal from the drive shaft sensor 31 that outputs a detection signal at a predetermined angular position of the intake valve drive shaft 3 and a detection signal from the crank angle sensor 117. The rotational phase of the valve drive shaft 3 is detected, and the operation amount of the electromagnetic retarder 24 is feedback-controlled so that the detection result approaches the target rotational phase.

Next, details of control of the variable operating valve / operating angle / lift variable mechanisms 112a and 112b and the center phase variable mechanisms 113a and 113b will be described.
FIG. 5 is a control block diagram of the variable operating angle / lift mechanism 112 (112a, 112b).
The target value calculation unit A is based on the engine operating state and the target value of the variable operating angle / lift mechanism 112 (target of the control shaft 13) corresponding to the target value (target operating angle) of the operating angle / lift characteristic of the intake valve 105. It calculates a rotation angle) theta _T.

Nominal response value calculation unit B receives the target value theta _T operating angle lift variable mechanism 112, the designer calculates the nominal response value theta _M obtained while the response according to the response characteristics desired (reference model) Output. That is, the normative response value θ _M is set as a transient target value that converges to the final target value θ _T with desired response characteristics.
Specifically, a reference model R (s) that provides a stable response to the following dynamic characteristics (motion equation) of the variable operating angle / lift mechanism 112 shown in the following equation (1) is expressed by the equation (2). The normative response value θ _M is calculated using equation (3).

T = J (d ² θ / dt ² ) + μ (dθ / dt) + Kθ (1)
Where T: drive torque, θ: rotation angle of the control shaft 13 of the operating angle / lift variable mechanism 112, J: moment of inertia of the operating angle / lift variable mechanism 112, μ: friction coefficient of the operating angle / lift variable mechanism 112, K: Spring constant of operating angle / lift variable mechanism 112 R (s) = ω ² / (s ² + 2ζωs + ω ² ) (2)
S: Laplace operator, ω: frequency, ζ: damping coefficient θ _M = θ _T · R (s) (3)
The feedforward manipulated variable calculator C calculates and outputs a feedforward manipulated variable for causing the operating angle / lift variable mechanism 112 to respond according to the normative model.

Specifically, the feedforward transfer function F _F (s) is inversely converted from the following dynamic characteristic transfer function P (s) of the operating angle / lift variable mechanism 112A, 112B as shown in the following equation (4). The product P ⁻¹ (s) · R (s) of the function P (s) ⁻¹ and the reference model R (s) is set.
F _F (s) = P (s) ⁻¹ R (s) (4)
Then, the feedforward drive current i _FF is calculated by multiplying the input target value θ _T by the transfer function F _F (s) as in the following equation (5).

i _FF = F _F (s) · θ _T (5)
When the drive current i of the electric actuator 17 is controlled by the drive voltage, it is converted into a feed-forward drive voltage V _FF to obtain the feed-forward drive current i _FF as a feed-forward operation amount and output.
Based on a deviation θ _ERR (= θ _M −θ _R ) between the reference response value θ _M and the actual response value (actual rotation angle) θ _R of the operating angle / lift variable mechanism 112, for example, In the case of PID control, the feedback drive current i _FB is calculated by using the proportional element P, the integral element I, and the differential element D according to the following equation (6), converted into a feedback drive voltage V _FB as a feedback operation amount, and output.

i _FB = (P + I / s + Ds) · θ _ERR (6)
Then, a drive voltage V as a total operation amount obtained by adding the feedforward drive voltage _VFF and the feedback drive voltage _VFB is output to the operating angle / lift variable mechanism 112 (electric actuator 17).
Such control is performed with a feedforward operation amount so that the operating angle / lift variable mechanism 112 responds according to the normative model, and the deviation between the normative response value and the actual response value caused by the variation of the mechanism or the environmental condition is determined. It is designed to absorb with the feedback manipulated variable.

However, if the calculation (integration calculation) using the integral element I is always performed when calculating the feedback operation amount (feedback drive current i _FB ) in the feedback operation amount calculation unit D, the following problems occur.
While from the target value theta _T changes, in a transient state in which the deviation between the target value theta _T and nominal response value theta _M occurs greatly, the operating angle-variable lift mechanism 112 to be absorbed by the integral operation amount It is difficult to capture only the variation in mechanism and environmental conditions, and the deviation θ _ERR between the normative response value θ _M and the actual response value θ _R of the operating angle / lift variable mechanism 112 should not be absorbed by an integral operation amount other than the above variation. It is likely to contain an amount. Doing integral calculation in this state, the integral value continues to increase without contributing to the absorption of the deviation, when approaching the target value theta _T is the integral value becomes excessive, overshoot occurs, convergence deterioration To do. The proportional element P generates an operation amount P · θ _ERR proportional to the deviation θ _ERR , and the operation amount Ds · θ _ERR due to the differential element D also acts in a direction to suppress overshoot, so both are appropriate. Act on.

Further, when the calculated value (drive voltage V) of the operation amount output to the variable operating angle / lift mechanism 112 exceeds the power supply voltage V0 of the electric actuator 17, the actual drive voltage V is saturated at the power supply voltage V0. put away, insufficient actual current to the drive current i in need, the actual response value theta _R deviates relative to nominal response value theta _M. Therefore, if the integral calculation is performed during this time, the integral value is excessively increased, resulting in overshoot and deterioration of convergence.

However, in the calculation of the feedback manipulated variable, eliminating completely integral operation, steady state deviation with respect to the target value theta _T remains will be, not be good control by variation When only other proportional operation and differential operation.
Therefore, returning to FIG. 5, the integral calculation switching unit E determines each of the above conditions. Under these conditions, the integral calculation switching unit E stops the integral calculation, and otherwise gives an instruction to execute the integral calculation to the feedback manipulated variable calculation unit D. Output.

FIG. 6 shows a flow of a routine for performing switching control of execution / stop of integral calculation by the feedback manipulated variable calculation unit D.
In step S1, reads the target value theta _T and nominal response value theta _M of the operating angle, the lift variable mechanism 112.
In step S2, a deviation Δθ _TM (= | θ _T −θ _M |) between the target value θ _T and the normative response value θ _M is calculated.

In step S3, it is determined whether or not the deviation Δθ _TM is equal to or smaller than a predetermined value Δθ0. If it is determined that the deviation Δθ _TM exceeds the predetermined value Δθ0, the process proceeds to step S8 and a feedback operation is performed as in the following equation (7). The integral calculation in the amount calculation is stopped (maintains the integral value I- ₁ immediately before the stop). Here, the predetermined value Δθ0 is escaped transients, is set to a size which absorbs without delay steady-state deviation while suppressing overshoot be started integral calculation can converge to the target value theta _T.

i _FB = (P + Ds) · θ _ERR + I ₋₁ (7)
I _-1: converting the feedback driving voltages V _FF obtained feedback drive current i _FB calculated by the formula of stopping the integration value above integral operation immediately before the integral operation is stopped (7).
When it is determined that the deviation Δθ _TM is equal to or less than the predetermined value Δθ0, the process proceeds to step S4, and the calculated value of the previous operation amount (drive voltage V = V _FF + V _FB ) is read.

Next, in step S5, the power supply voltage V0 of the electric actuator 17 is read.
In step S6, it is determined whether the drive voltage V is equal to or lower than the power supply voltage V0. If it is determined that the drive voltage V exceeds the power supply voltage V0, the process proceeds to step S8, and the integration calculation in the calculation of the feedback manipulated variable is stopped.
If it is determined in step S6 that the previous operation amount calculation value (absolute value | V | of the drive voltage V) is equal to or lower than the power supply voltage V0, the process proceeds to step S7 to calculate the feedback operation amount using the above equation (6 ), Including integration.

In this way, changed target value theta _T is, when the deviation [Delta] [theta] _TM between the target value theta _T and nominal response value theta _M is larger than the predetermined value Derutashita0, and the calculated drive voltage V drive power supply voltage V0 By stopping the integral calculation when the value exceeds the value, it is possible to prevent the integral value from continuing to increase during these periods and to prevent overshoot.
Also, when other than these, by permitting integration operation, it can be converged to the target value theta _T without leaving any steady-state error.

7, when the deviation [Delta] [theta] _TM between the target value theta _T and nominal response value theta _M is larger than the predetermined value Derutashita0, showing the effect of overshoot prevention by stopping the integral operation.
As shown in FIG. 8, the effect of preventing overshoot by stopping the integral calculation when the drive voltage V exceeds the drive power supply voltage V0 is shown.
The same control is performed for the center phase variable mechanism 113 (113a, 113b).

FIG. 9 is a control block diagram of the center phase variable mechanism 113.
When applied to the center phase variable mechanism 113, the control amount is replaced with the rotational phase of the intake valve drive shaft 3 and the operation amount is replaced with the operation amount of the electromagnetic retarder 24. In other words, the rotational phase of the intake valve drive shaft 3 (center phase of the intake valve 105) can be converged to the target value while preventing overshoot. The flow of a routine for switching control of execution / stop of integration calculation is the same as that in FIG.

  In the present embodiment, the drive current of the electric actuator 17 and the electromagnetic retarder 24 is controlled by the drive voltage. However, the drive voltage is constantly turned ON and OFF, and the ON time ratio (energization duty ratio) is controlled. The present invention can also be applied to those performed by duty control controlled by. In this case, it is determined in step S6 whether the duty ratio is near 100%. When the duty ratio is close to 100%, the operation amount calculation value exceeds the maximum drive amount and the energization duty ratio is saturated. Therefore, it progresses to step S8 and stops the integral calculation.

As described above, the control for stopping the integral calculation under the predetermined condition is performed on the operating angle / lift variable mechanism 112 and the center phase variable mechanism 113, and the lift amount of the intake valve and the center phase are exceeded to the respective target values. By converging without a chute, fluctuations in the intake air amount, as well as torque fluctuations and air-fuel ratio fluctuations can be prevented, and drivability and exhaust purification performance can be improved.
In particular, in the idle / low load range where the lift amount is small, the sensitivity of the change in the intake air amount with respect to the change in the operation amount is large, so the engine vibration accompanying the torque change and the exhaust emission due to the air-fuel ratio change are likely to deteriorate. The effect of suppressing fluctuations in the amount of air and preventing these deteriorations is great.

In addition, when applied to a V-type engine having a variable valve mechanism in each bank as in this embodiment, the torque step between banks caused by fluctuations in the intake air amount for each bank is also suctioned for each bank. By suppressing fluctuations in the air amount, it can be effectively eliminated, and the torque of each cylinder can be increased smoothly during acceleration, improving acceleration performance.
Further, in the present embodiment, by applying the integral calculation stop control according to the present invention to both the operating angle / lift variable mechanism 112 and the center phase variable mechanism 113, the above-described effect can be obtained in the independent control. Of course, when both mechanisms are controlled at the same time, if the integral control is not stopped, the deterioration of convergence to each target value will act synergistically, resulting in large intake fluctuations. Can be prevented.

However, it is a matter of course that a sufficient effect can be obtained even if the integral calculation stop control according to the present invention is applied to only one of the operating angle / lift variable mechanism 112 and the center phase variable mechanism 113.
In the above embodiment, the variable valve mechanism (variable operating angle / lift mechanism 112, variable center phase mechanism 113) that varies the characteristics of the intake valve is shown. However, the characteristics of the exhaust valve are variable. In the variable valve mechanism as described above, by making the exhaust valve characteristic variable, it is possible to make the intake air amount characteristic and thus the engine torque variable, so that the same effect can be obtained by applying the present invention. .

The configuration deviation [Delta] [theta] _TM between the target value theta _T and nominal response value theta _M stops integral operation only when greater than the predetermined value Derutashita0, or integral operation only when the operation amount calculated value exceeds the maximum drive amount In the embodiment, the above-described effects can be obtained.

The block diagram of the internal combustion engine in embodiment of this invention. The perspective view which shows the structure of the working angle / lift variable mechanism in the said embodiment. The side view of the said working angle and lift variable mechanism. Sectional drawing which shows the center phase variable mechanism in the said embodiment. The control block diagram of the said operating angle and lift variable mechanism. 7 is a flowchart showing a routine for switching control of execution / stop of integral calculation by a feedback operation amount calculation unit in the variable operating angle / lift mechanism. The figure which shows the effect of the overshoot prevention by stopping integral calculation when deviation (DELTA) (theta) _{TM of} target value (theta) _T and normative response value (theta) _M is larger than predetermined value (DELTA) (theta) 0. The figure which shows the effect of the overshoot prevention by stopping integral calculation, when the drive voltage V exceeds the drive power supply voltage V0. The control block diagram of the said center phase variable mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Internal combustion engine, 104 ... Electronically controlled throttle, 105 ... Intake valve, 107 ... Exhaust valve, 111a, 111b ... Oxygen sensor, 112a, 112b ... Operating angle / lift variable mechanism (VEL), 113a, 113b ... Center phase variable mechanism (VTC), 114 ... Electronic control unit (ECU)

Claims (6)

Equipped with a variable valve mechanism that changes the valve opening characteristics of the engine valve,
Target value calculating means for calculating a target value of the variable valve mechanism corresponding to a target value of the valve opening characteristic of the engine valve;
Normative response value calculating means for calculating a normative response value when the variable valve mechanism is caused to respond with a specified response characteristic;
A feedforward manipulated variable calculating means for calculating a feedforward manipulated variable for causing the variable valve mechanism to respond with a prescribed response characteristic;
Feedback manipulated variable calculating means for calculating a feedback manipulated variable for eliminating a deviation between the reference response value and the actual response value of the variable valve mechanism;
Based on the feedforward operation amount and the feedback operation amount, an operation amount calculation unit that calculates an operation amount output to the drive unit of the variable valve mechanism,
In a control device for a variable valve mechanism configured to include:
Deviation calculating means for calculating a deviation between the target value of the variable valve mechanism and the reference response value;
An integral calculation stop means for stopping calculation by an integral element when calculating the feedback manipulated variable when the deviation between the target value of the variable valve mechanism and the reference response value is a predetermined value or more;
A control apparatus for a variable valve mechanism, comprising: Equipped with a variable valve mechanism that changes the valve opening characteristics of the engine valve,
Target value calculating means for calculating a target value of the variable valve mechanism corresponding to a target value of the valve opening characteristic of the engine valve;
Normative response value calculating means for calculating a normative response value when the variable valve mechanism is caused to respond with a specified response characteristic;
A feedforward manipulated variable calculating means for calculating a feedforward manipulated variable for causing the variable valve mechanism to respond with a prescribed response characteristic;
Feedback manipulated variable calculating means for calculating a feedback manipulated variable for eliminating a deviation between the reference response value and the actual response value of the variable valve mechanism;
Based on the feedforward operation amount and the feedback operation amount, an operation amount calculation unit that calculates an operation amount output to the drive unit of the variable valve mechanism,
In a control device for a variable valve mechanism configured to include:
An operation amount determination means for determining whether or not the calculated value of the operation amount output to the drive means of the variable valve mechanism is equal to or greater than the maximum drive amount of the drive means;
Integration that stops the calculation by the integral element when calculating the feedback operation amount when the calculated value of the operation amount output to the drive unit of the variable valve mechanism is equal to or greater than the maximum drive amount of the drive unit Calculation stop means;
A control apparatus for a variable valve mechanism, comprising:   The drive means is an electric actuator having an operation amount as a drive voltage, and it is determined that the calculated value of the operation amount is equal to or greater than a maximum drive amount by being equal to or greater than a power supply voltage of the electric actuator. The control apparatus for a variable valve mechanism according to claim 1 or 2.   The drive means is an electric actuator having an operation amount as an energization duty ratio, and determines that the calculated value of the operation amount is equal to or greater than a maximum drive amount by the energization duty ratio being near 100%. The control apparatus for a variable valve mechanism according to claim 1 or 2.   The variable valve mechanism according to any one of claims 1 to 4, wherein the variable valve mechanism is a mechanism that varies at least one of an operating angle and a lift amount of an engine valve. Control device.   The control apparatus for a variable valve mechanism according to any one of claims 1 to 4, wherein the variable valve mechanism is a mechanism that varies a center phase of the engine valve.

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