JP2004027897A - Controlling device of turbo supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly return to a normal operation even if a compressor is transitionally operated in an abnormal condition, while heightening accuracy of judging whether the compressor is transitionally operated in an abnormal condition, or in a condition immediately before the abnormal condition. <P>SOLUTION: This controlling device of a turbo supercharger comprises a variable capacity turbo supercharger (21) equipped with a geometry variable mechanism (24) capable of receiving a control amount and changing geometry of a turbine; and a control amount setting means (31) for setting the control amount to the geometry variable mechanism. The device also comprises a control amount correcting means (31) for correcting the control amount to a side for increasing the capacity of the turbo supercharger in a condition that an intake compressor is transitionally operated in an abnormal condition, or in a condition immediately before it is intermittently operated in an abnormal condition from judgement results for judging whether the compressor is transitionally operated in an abnormal condition, or in a condition immediately before the abnormal condition based on an actual supercharging pressure and an actual gas flow rate passing through the compressor. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for a turbocharger, and more particularly to a control in a transient state when used in combination with an automobile engine.
[0002]
[Prior art]
A turbocharger having a variable geometry mechanism capable of changing the turbine geometry, a map of a target supercharging pressure with the engine speed and load as parameters, and a sensor for detecting the actual supercharging pressure The target supercharging pressure is calculated according to the engine speed and load, and the control amount to the geometry variable mechanism is adjusted so that the actual supercharging pressure detected by the sensor matches the target supercharging pressure. There is one that performs feedback control (see JP-A-5-272345).
[0003]
[Problems to be solved by the invention]
By the way, the efficiency of the compressor arranged coaxially with the turbine is represented by taking the corrected flow rate Q * on the horizontal axis and the pressure ratio on the vertical axis as shown in FIG. As is well known, when a compressor that compresses intake air is operated in a region (abnormal operation region) outside a shaded portion (normal operation region), undesired phenomena such as surging, choking and turbine overspeed occur, and thus an abnormal condition is caused. The operating point of the compressor must be set so that it does not enter the operating range.
[0004]
However, when a turbocharger is used in combination with an automobile engine, the operating point of the compressor may jump into the abnormal operating range transiently with a rapid change of the accelerator pedal, and it is temporary. Also, abnormal operation of the compressor occurs. For example, when the accelerator pedal is suddenly depressed to perform start and rapid acceleration, the fuel injection amount is correspondingly increased and the exhaust amount (accordingly, the corrected flow rate) rapidly increases. At this time, if the geometry variable mechanism is a variable nozzle of the turbine, the nozzle opening is increased (given a control amount to the side where the capacity of the turbocharger is increased), but the nozzle opening is increased. If the response of the compressor is delayed, the operating point of the compressor moves to the right or to the upper right in FIG. 4, and jumps into an abnormal operating region in which choking or excessive rotation of the turbine occurs.
[0005]
Further, when the accelerator pedal is released and the vehicle is rapidly decelerated during high-speed steady operation, the fuel injection amount is reduced and the exhaust amount is rapidly reduced. At this time, if the geometry variable mechanism is a variable nozzle of the turbine, the nozzle opening degree is reduced (given a control amount to the side where the capacity of the turbocharger decreases), but the nozzle opening degree is reduced. If the response of the compressor is delayed, the operating point of the compressor may move to the left in FIG. 4 and jump into an abnormal operating region where surging occurs.
[0006]
In this case, if the inventor of the present application can know the parameters that determine the compressor efficiency (the parameters on the horizontal axis and the vertical axis in FIG. 4), the operating point of the compressor is abnormally operated based on the parameters. I thought that I could judge whether it was in the area or not.
[0007]
For example, in FIG. 4, the corrected flow rate Q * on the vertical axis is a value obtained by correcting the gas flow rate Q passing through the compressor by the gas temperature T1 and the gas pressure P1, and the pressure ratio on the vertical axis is the ratio between the supercharging pressure and the atmospheric pressure. is there. Therefore, it can be seen that the actual gas flow rate Q passing through the compressor and the actual supercharging pressure may be used as basic parameters for determining whether the operating point of the compressor is in the abnormal operation range.
[0008]
Therefore, the present invention determines whether the compressor is in a transient abnormal operation or is in a state immediately before the transient abnormal operation based on the actual supercharging pressure and the actual gas flow rate passing through the compressor. Judgment, when the transient abnormal operation of the compressor occurs or immediately before the transient abnormal operation, by correcting the control amount given to the geometry variable mechanism on the side where the capacity of the turbocharger increases, the transient transient operation of the compressor is performed. It is an object of the present invention to promptly return to the normal operation even if any abnormal operation is performed, or to maintain the normal operation immediately before the transient abnormal operation of the compressor is performed.
[0009]
On the other hand, since the efficiency of the turbocharger is the total efficiency of the respective efficiencies of the compressor and the turbine, it is necessary to consider a parameter representing the turbine efficiency when considering the entire turbocharger. In this case, since the turbine efficiency is usually expressed by taking the speed ratio on the horizontal axis and the efficiency on the vertical axis, there is no common parameter for expressing each efficiency of the compressor and the turbine.
[0010]
Therefore, when the turbocharger is viewed as a whole, the actual supercharging pressure and the actual gas flow rate passing through the compressor may be used as parameters for determining whether or not the turbocharger is in a transient abnormal operation. The experiment was performed to determine whether or not there were other optimal parameters.The actual supercharging pressure and the actual gas flow rate passing through the compressor were changed during transient abnormal operation of the turbocharger as a whole. When the parameter is used as a parameter, the boundary between the abnormal operation range and the normal operation range of the turbocharger as a whole is not clear, and an ambiguous part is generated. When the actual exhaust flow rate is adopted instead of, that is, when the actual supercharging pressure and the actual exhaust flow rate are used as parameters, the boundary between the abnormal operation area and the normal operation area of the turbocharger as a whole is grasped. It was found hungry.
[0011]
Therefore, the present invention determines whether the turbocharger is in a transient abnormal operation or is in a state immediately before the transient abnormal operation based on the actual supercharging pressure and the actual exhaust flow rate. By increasing the accuracy of the determination, the amount of control given to the geometry variable mechanism on the side where the capacity of the turbocharger increases at the time of transient abnormal operation of the turbocharger or immediately before the abnormal operation, while increasing the accuracy of the determination. By making correction, even if transient abnormal operation of the turbocharger occurs, it can be quickly returned to normal operation, or can be restored to normal operation immediately before the transient abnormal operation of the turbocharger. The purpose is to stop.
[0012]
On the other hand, in the conventional device described above, the target boost pressure rises in a stepwise manner at the time of rapid start acceleration, and feedback control is performed so that the actual boost pressure follows the target boost pressure. Since the so-called overshoot phenomenon, in which the supercharging pressure greatly exceeds the supercharging pressure, occurs, when it is determined that the vehicle is starting and suddenly accelerating, feedback control of the supercharging pressure is temporarily interrupted, and the actual supercharging pressure is reduced to the target supercharging. The control amount given to the variable nozzle slightly before reaching the supply pressure is changed to a value that maximizes the capacity of the turbocharger.
[0013]
In this conventional device, it is determined based on the actual supercharging pressure that the vehicle is at the time of starting rapid acceleration or that the actual supercharging pressure is slightly before reaching the target supercharging pressure. Since the technology is not created based on the efficiency or the efficiency of the turbocharger as a whole, the actual gas flow rate and the actual exhaust flow rate passing through the compressor are not used. For this reason, if only the actual supercharging pressure is used as a parameter, an abnormal operation range and a normal operation range will occur depending on the actual gas flow rate and the actual exhaust flow rate passing through the compressor. It is not possible to accurately determine whether or not a transient abnormal operation has occurred.
[0014]
[Means for Solving the Problems]
According to the first aspect of the present invention, a variable displacement turbocharger including a variable geometry mechanism that can change the geometry (geometric shape) of a turbine in response to a controlled variable, and sets the controlled variable for the variable geometry mechanism. The control device for a turbocharger comprising a control amount setting unit, based on an actual supercharging pressure and an actual gas flow rate passing through the compressor, whether or not a transient abnormal operation of the compressor is detected or a transient abnormality is detected. An abnormal operation time determining means for determining whether or not the turbocharger is in a state immediately before the operation, and a turbocharger for the turbocharger in the state immediately before the transient abnormal operation of the intake compressor or the transient abnormal operation based on the determination result. A control amount correcting means for correcting the control amount is provided on the side where the capacity increases.
[0015]
According to a second aspect of the present invention, there is provided a variable displacement turbocharger having a geometry variable mechanism capable of changing the geometry (geometric shape) of a turbine in response to a control amount, and setting the control amount for the variable geometry mechanism. A turbocharger control device comprising a control amount setting means, wherein whether or not the turbocharger is in a transient abnormal operation or a transient abnormal operation is determined based on the actual supercharging pressure and the actual exhaust flow rate. Abnormal operation determining means for determining whether or not the turbocharger is in a state immediately before the time, and a turbocharger in the transient abnormal operation of the turbocharger or in the state immediately before the transient abnormal operation based on the determination result. Control amount correction means for correcting the control amount on the side where the capacity increases.
[0016]
According to a third aspect of the present invention, there is provided a constant-capacity turbocharger capable of changing the opening of the wastegate valve in response to a control amount, and control amount setting means for setting the control amount to the wastegate valve. In the control device of the turbocharger, based on the actual supercharging pressure and the actual gas flow rate passing through the compressor, whether or not the intake compressor is in a transient abnormal operation or in a state immediately before the transient abnormal operation is performed. Abnormal operation determination means for determining whether or not there is, and based on a result of the determination, in the state immediately before the transient abnormal operation of the intake compressor or during the transient abnormal operation, the opening degree of the wastegate valve is increased. Control amount correction means for correcting the control amount.
[0017]
According to a fourth aspect of the present invention, there is provided a constant-capacity turbocharger capable of changing the opening of the wastegate valve in response to a control amount, and a control amount setting means for setting the control amount to the wastegate valve. In the control device of the turbocharger, based on the actual supercharging pressure and the actual exhaust flow rate, it is determined whether the turbocharger is in a transient abnormal operation state or is in a state immediately before the abnormal operation state. Means for judging abnormal operation, and, based on the judgment result, correcting the control amount in such a way that the opening of the wastegate valve increases in the state immediately before the transient abnormal operation of the intake compressor or immediately before the transient abnormal operation. Control amount correcting means for performing the control.
[0018]
【The invention's effect】
According to the first and third aspects of the invention, it is determined whether or not the compressor is in a transient abnormal operation based on the actual supercharging pressure and the actual gas flow rate passing through the compressor, which are parameters representing the compressor efficiency. It is determined whether or not it is in the state immediately before the abnormal operation, so that the accuracy of the determination is improved. Based on the result of the accurate determination, the transient abnormal operation or the transient abnormal operation of the compressor is performed. In the state immediately before the above, the control amount is corrected to the side where the capacity of the turbocharger increases in the invention according to claim 1, and in the invention according to claim 3, the opening degree of the waste gate valve increases. By correcting the control amount to, even if transient abnormal operation of the compressor occurs, it can be returned to normal operation promptly, or normal operation immediately before the transient abnormal operation of the compressor can be performed. It can be kept to.
[0019]
According to the second and fourth aspects of the present invention, it is determined whether or not the turbocharger is in a transient abnormal operation based on the actual supercharging pressure and the actual exhaust flow rate, which are parameters representing the overall efficiency of the turbocharger. Or the state immediately before the transient abnormal operation is determined, the accuracy of the determination is improved, and the accurate determination result indicates that the turbocharger has a transient abnormal operation. Alternatively, in a state immediately before transient abnormal operation, the control amount is corrected to increase the capacity of the turbocharger according to the second aspect of the invention, and the wastegate valve is corrected according to the fourth aspect of the invention. By correcting the control amount to the side where the opening of the turbocharger increases, even if a transient abnormal operation of the turbocharger occurs, the turbocharger can quickly return to the normal operation or the transient state of the turbocharger. To normal operation immediately before abnormal abnormal operation is performed It can be.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an engine according to an embodiment of the present invention.
[0021]
An EGR passage 4 connecting the exhaust passage 2 and the collector 3a of the intake passage 3 is provided with a diaphragm type EGR valve 6 which responds to a control pressure from a pressure control valve (not shown). The pressure control valve is driven by a duty control signal from the engine controller 31 so as to obtain a predetermined EGR rate according to operating conditions.
[0022]
The engine includes a common rail type fuel injection device 10. The fuel injection device 10 mainly includes a fuel tank (not shown), a supply pump 14, a common rail (pressure accumulating chamber) 16, and a nozzle 17 provided for each cylinder. After being stored once, the high-pressure fuel in the accumulator 16 is distributed to the nozzles 17 for the number of cylinders.
[0023]
The nozzle 17 (fuel injection valve) includes a needle valve, a nozzle chamber, a fuel supply passage to the nozzle chamber, a retainer, a hydraulic piston, a return spring, and the like, and is a three-way valve (illustrated) interposed in the fuel supply passage to the hydraulic piston. No) is interposed. When the three-way valve (electromagnetic valve) is OFF, the needle valve is in a seated state, but when the three-way valve is ON, the needle valve rises and fuel is injected from the injection hole at the tip of the nozzle. That is, the fuel injection start timing is adjusted by the switching timing of the three-way valve from OFF to ON, and the fuel injection amount is adjusted by the ON time. If the pressure in the accumulator 16 is the same, the longer the ON time, the larger the fuel injection amount. Become.
[0024]
The exhaust passage 2 downstream of the opening of the EGR passage 4 is provided with a variable-capacity turbocharger 21 in which a turbine 22 that converts heat energy of exhaust gas into rotational energy and a compressor 23 that compresses intake air are connected coaxially. A variable nozzle 24 (geometry variable mechanism) driven by an actuator 25 is provided at the scroll inlet of the turbine 22. The engine controller 31 allows the variable nozzle 24 to obtain a predetermined supercharging pressure from a low rotation speed range. On the low rotation speed side, the nozzle opening (inclined state) for increasing the flow velocity of the exhaust gas introduced into the turbine 22 is controlled, and on the high rotation speed side, the exhaust gas is introduced into the turbine 22 without resistance to the nozzle opening degree (fully opened state).
[0025]
The actuator 25 includes a diaphragm actuator 26 that drives a variable nozzle 26 in response to a control pressure, and a pressure control valve 27 that adjusts a control pressure applied to the diaphragm actuator 26. A duty control signal is generated so as to achieve the target nozzle opening, and the duty control signal is output to the pressure control valve 27.
[0026]
The engine controller 31 to which signals from the accelerator sensor 32, the sensor 33 for detecting the engine rotational speed and the crank angle, the water temperature sensor 34, the air flow meter 35, and the supercharging pressure sensor 36 are input, based on these signals, the target EGR rate And the target supercharging pressure, the EGR control and the supercharging pressure control are performed in cooperation.
[0027]
Here, a description will be given of a case where the present invention is applied to a prior application device (see Japanese Patent Application Laid-Open No. 2002-115551) previously proposed by the same applicant as the present applicant. Is shown as a block diagram.
[0028]
In the figure, for example, at the operation timing that is visited every 10 msec, all the blocks from 42 to 55 finish the operation instantaneously in the order of the arrows.
[0029]
Briefly, in FIG. 2, the target EGR rate calculation unit 42 calculates the engine rotation speed Ne [rpm] and the target fuel injection amount Qsol [mm].³/ St. cyl] and the target EGR rate Megr is calculated.
[0030]
The target fuel injection amount Qsol is basically a value determined by the engine speed and the accelerator opening. Here, the target fuel injection amount Qsol is a variable representing the load. Therefore, an accelerator opening, an engine torque, or the like can be used instead of Qsol.
[0031]
The value of the target EGR rate Megr becomes smaller after the engine warm-up is completed, as Qsol increases when Ne is constant, and as Ne increases when Qsol is constant.
[0032]
The EGR control unit 55 performs the EGR control based on the Megr. However, since this part is not directly related to the present invention, a detailed description is omitted.
[0033]
The delay processing unit 43 uses the target EGR rate Megr thus obtained and Kin × KVOL, and
Megrd = Megr × KIN × KVOL × Ne × KE2 #
+ Megrd_n-1× (1-KIN × KVOL × Ne × KE2 #) (1)
However, KIN: a value corresponding to volumetric efficiency,
KVOL: VE / NC / VM,
VE: displacement,
NC: Number of cylinders,
VM: intake system volume,
KE2 #: constant,
Megrd_n-1: Previous Megrd,
The EGR rate Megrd [%] at the intake valve position is calculated by simultaneously performing the delay processing and the unit conversion (per cylinder / per unit time) by the following equation.
[0034]
Here, KIN and KVOL on the right side of Expression (1) are values necessary to represent a response delay of intake air from the collector inlet to the intake valve, as described in Expression (6) described later. The change is in line with this. KIN and KVOL also appear in equations (6) and (7) described later, but since they have the same value, description thereof will be omitted in equations (6) and (7) described later.
[0035]
Ne × KE2 # on the right side of the above equation (1) is a value for unit conversion. Since this Megrd responds to the target EGR rate Megr with a first-order lag, it represents the actual EGR rate.
[0036]
The target intake air amount calculation unit 44 makes the calculation method different between an EGR operation region and an EGR non-operation region to set a target intake air amount tQac [mg / st. cyl]. That is, in the non-operating region of the EGR, the engine speed Ne and the target fuel injection amount Qsol become parameters, and the value of tQac increases as Qsol increases when Ne is constant. The rate of dependence on Ne is small, but when Qsol is constant, it gradually decreases as Ne increases.
[0037]
On the other hand, in the EGR operation range, the actual EGR rate Megrd and the rotation speed Ne become parameters, and the value of tQac increases as Qsol increases when Ne is constant.
[0038]
The target exhaust air amount calculation unit 45 calculates the target intake air amount tQac and the target fuel injection amount Qsol from
tQexh = (tQac + Qsol × GKQFVNT #) × Ne / KCON # (2)
Here, GKQFVNT #: conversion coefficient,
KCON #: constant,
The target displacement tQexh [g / sec] is calculated by the following equation. This is based on the assumption that the total of the amount of the Qsol fuel burning and becoming exhaust and the target intake air amount tQac becomes the exhaust flow rate (ignoring a rise in temperature). Here, the unit of Qsol is [mm³/ St. cyl], the conversion coefficient GKQFVNT # [mm³/ Mg] to convert the unit of tQexh to tQac [mg / st. cyl], and by multiplying by Ne / KCON #, [mg / st. cyl] to [g / sec].
[0039]
The target opening ratio calculation unit 46 makes the calculation method different between the EGR operation region and the EGR non-operation region, and performs the exhaust temperature correction and the abnormal operation correction to perform the target opening ratio Rvnt [%] of the variable nozzle 24. ] Is calculated. The calculation of Rvnt will be described in detail with reference to FIG.
[0040]
Here, the target opening ratio of the variable nozzle 24 is a value obtained by multiplying the ratio of the current nozzle area to the nozzle area when the variable nozzle 24 is fully opened by 100 and expressing the ratio as a percentage. Therefore, when the variable nozzle 24 is fully opened, the opening ratio is 100%, and when the variable nozzle 24 is fully closed, the opening ratio is 0%. The turbocharger 21 of the embodiment is of a type in which the supercharging pressure is the smallest when the variable nozzle 24 is fully opened and the supercharging pressure is the largest when the variable nozzle 24 is fully closed. The capacity of the supercharger is reduced, and the supercharging pressure is increased.
[0041]
The advance processing unit 47 performs an advance process on the target opening ratio Rvnt in consideration of a response delay of the supercharger 21 and intake and exhaust (the advance process in consideration of the response delay of the actuator 25 itself is performed by an advance processing unit 53 described later). Do). For example, using a time constant equivalent value Tcvnt of advance correction and a target opening ratio Rvnt,
Cavnt = Rvnt × Tcvnt + Cavnt_n-1× (1-Tcvnt) (3)
However, Cavnt_n-1: Previous Cavnt,
The expected opening ratio Cavnt [%] is calculated by the following equation, and from this value and the target opening ratio Rvnt,
Avnt　f = Gkvnt × Rvnt− (Gkvnt−1) × Cavnt_n-1… (4)
Here, Gkvnt: advance correction gain,
Cavnt_n-1: Previous Cavnt,
The advance correction is performed according to the following equation, and the feedforward amount Avnt of the target opening ratio is calculated.　Calculate f [%].
[0042]
Here, the time constant equivalent value Tcvnt of the advance correction of the equation (3) and the advance correction gain Gkvnt of the equation (4) are obtained by moving the variable nozzle 24 to the open side and moving the variable nozzle 24 to the close side. You are searching for a different table when you are searching.
[0043]
Next, blocks 48 to 52 are portions that perform feedback control of the opening ratio so that the actual intake air amount matches the target intake air amount.
[0044]
First, the cylinder intake air amount calculator 48 calculates the engine speed Ne [rpm] and the intake air flow rate Qas0 obtained from the output of the air flow meter 35 (abbreviated as “AFM output” in the figure).
Qac0 = (Qas0 / Ne) × KCON # (5)
Where KCON #: constant,
The intake air amount Qac0 per cylinder at the position of the air flow meter 35 is calculated by the following formula, and the processing for the transport delay (dead time) from the air flow meter 35 to the collector section 3a is performed. The intake air amount Qacn per cylinder is obtained, and for this Qacn,
Qac = Qacn × KIN × KVOL
+ Qac_n-1× (1-KIN × KVOL) (6)
However, Qac_n-1: Previous Qac,
(The first-order lag equation), the intake air amount per cylinder at the intake valve position (this intake air amount is hereinafter referred to as “cylinder intake air amount”) Qac [mg / st. cyl]. Equation (6) represents a response delay of intake air from the collector inlet to the intake valve. The cylinder intake air amount Qac represents the actual intake air amount in relation to the target intake air amount tQac.
[0045]
In the delay processing unit 49, from the target intake air amount tQac,
tQacd = tQac × KIN × KVOL × KQA #
+ TQacd_n-1× (1-KIN × KVOL × KQA #) (7)
Where KQA #: constant,
tQacd_n-1: The previous tQacd,
The target intake air amount delay processing value tQacd is calculated by the following equation (first-order delay expression), and the difference between the cylinder intake air amount Qac and the target intake air amount delay processing value tQacd is calculated as a control error Eqac by the subtraction unit 50.
Eqac = Qac−tQacd (8)
The control deviation Eqac is calculated by the following equation.
[0046]
Then, based on the control error Eqac, the opening ratio feedback amount calculation unit 51 calculates the opening ratio feedback amount Avnt.　Calculate fb. For example, from the control deviation Eqac
Ravfbp = Gkvntp × Eqac (9)
Here, Gkvntp: proportional gain,
The proportional correction value Ravfbp is calculated by
Ravfbi = Ravfbin-1 + Gkvnti × Eqac (10)
Where Gkvnti: integral gain,
Ravfbin-1: the previous Ravfbi,
The integral correction value Ravfbi is calculated by the following equation, and the sum of these is used as the feedback amount Avnt of the opening ratio.　fb, and the adding unit 52 calculates the feedforward amount Avnt of the target opening ratio.　f is the feedback amount Avnt obtained in this way.　The value obtained by adding fb is calculated as the command opening ratio Avnt.
[0047]
In the case of general feedback control, the control deviation uses the difference between Qac as the actual intake air amount and the target intake air amount tQac. Here, the target deviation is set as the control deviation Eqac as in the above equation (8). The target intake air amount delay processing value tQacd is employed instead of the intake air amount tQac. This means that even a control object having a large dead time and a large response time constant (see FIG. 8), such as a turbocharger having a variable nozzle 24, can be easily implemented without performing complicated control such as modern control. The method makes it possible to achieve both the stability and the responsiveness of the supercharging pressure control during the transition. That is, when normal PI control is performed on the turbocharger having the variable nozzle 24 so that the cylinder intake air amount Qac matches the target intake air amount tQac, the integral correction is performed in a region where the deviation from tQac is large. The value accumulates, and the cylinder intake air amount Qac as an actual value oscillates due to the integral correction value.If tQacd is used instead of tQac, the difference between Qac and tQacd is smaller than the difference from tQacd. As much as possible, accumulation of the integral correction value calculated by the above equation (10) is suppressed, and the feedback gain can be increased. Thus, the actual value (Qac) can be quickly converged to the target value (tQacd) without oscillating at the time of transition.
[0048]
The advance processing unit 53 performs an advance process in consideration of a response delay of the actuator 25. For example, using the time constant equivalent value Tcact of the actuator advancement correction and the command opening ratio Avnt,
Cvact = Avnt × Tcact + Cvact_n-1× (1-Tcact) (11)
However, Cvact_n-1: Previous Cvact,
The expected opening ratio Cvact is calculated by the following equation, and from this value and the command opening ratio Avnt,
Trvnt = Gkact × Avnt− (Gkact−1) × Cvact_n-1… (12)
Here, Gkact: an actuator advance correction gain,
Cvact_n-1: Previous Cvact,
The lead correction is performed by the following equation to calculate the final command opening ratio Trvnt.
[0049]
Here, the time constant equivalent value Tcact of the actuator advance correction of the equation (11) and the actuator advance correction gain Gkact of the equation (12) are obtained when the variable nozzle 24 is moved to the open side and when the variable nozzle 24 is closed. Use a different value (constant value) when moving to.
[0050]
The control command duty value setting unit 54 performs linearization processing on the final command opening ratio Trvnt to obtain a command opening ratio linearization processing value Ratdty, and performs hysteresis processing and temperature correction on this Ratdty to obtain a basic command duty value basic value. Value Dty　h, and this Dty　Further, operation confirmation control is performed on h to obtain a control command duty value Dtyvnt.
[0051]
Here, the linearization processing is necessary when the command signal (duty value) to the actuator has a non-linear characteristic with respect to the aperture ratio. The hysteresis process is required when the duty ratio differs between when the opening ratio is increasing and when it is decreasing. Further, the temperature correction is necessary when the relationship between the opening ratio and the duty value changes under the influence of the ambient temperature.
[0052]
FIG. 3 is a detailed block diagram of the target opening ratio calculation unit 46 of FIG.
[0053]
First, the target opening ratio basic value calculation unit 61 divides the EGR operation region into a non-operation region, and calculates a target opening ratio basic value Rvnt0 in the EGR operation region from the target exhaust gas amount tQexh and the target EGR rate Megr in the EGR operation region. In the EGR non-operating region, a target opening ratio basic value Rvnt0 in the EGR non-operating region is calculated from the target exhaust amount tQexh and the target fuel injection amount Qsol.
[0054]
In the EGR operation range, Rvnt0 is a value that decreases as Megr increases when tQexh is constant. This is because when the EGR rate increases, the fresh air decreases accordingly, and when the air-fuel ratio leans to the rich side, smoke is generated. Therefore, it is necessary to reduce Rvnt0 and increase the supercharging pressure as Megr increases. . Also, when Megr is constant, the value of Rvnt0 increases as tQexh increases.
[0055]
In the non-operating region of EGR, Rvnt0 is a value that becomes large in a region where tQexh is relatively large when Qsol is constant. Further, when tQexh is constant in this region, the value increases as Qsol increases.
[0056]
As described above, the basic value Rvnt0 of the target opening ratio of the variable nozzle 24 is calculated by the target opening ratio basic value calculation unit 61 in the same manner as in the prior application device.
1) a correction portion for correcting the exhaust gas temperature with respect to the target opening ratio basic value;
2) A correction part for correcting the target opening ratio during abnormal operation and
Is newly added.
[0057]
First, the correction part 1) includes a load correction value calculation unit 62 and an addition unit 63. That is, the load correction value calculation unit 62 calculates the load correction value TRAVQF of the target opening ratio from the target fuel injection amount Qsol and the target exhaust flow rate tQexh, and the addition unit 63 adds this load correction value TRAVQF to the target opening ratio basic value Rvnt0. The calculated value is calculated as the target opening ratio Rvnt1 of the variable nozzle 24.
[0058]
Although the target fuel injection amount Qsol is used as a parameter for calculating the load correction value, it is a substitute value for the exhaust gas temperature (the exhaust gas temperature increases as Qsol increases). That is, the load correction value takes into account the difference in exhaust gas temperature. Since the turbo efficiency (combined efficiency of the compressor efficiency and the turbine efficiency) is greatly affected not only by the exhaust amount but also by the exhaust temperature, only the exhaust amount is used as a parameter for calculating the target opening ratio basic value Rvnt0. , Can not respond to the difference of exhaust temperature. For example, when Rvnt0 is matched with the exhaust temperature on the low load side, if the actual exhaust temperature becomes higher than the exhaust temperature used for the matching of Rvnt0 when the load becomes higher, the turbocharger is provided by the temperature difference. Since the efficiency is increased and the supercharging pressure is increased, there is a possibility that the supercharging pressure exceeds the target supercharging pressure, resulting in a so-called overboost. Therefore, when the load correction value (positive value) is corrected to the side where the opening ratio is increased (the side where the supercharging pressure is reduced) by the increase in the turbo efficiency due to the temperature difference, the over-boost can be performed even at a high load. It can be prevented. In other words, the use area of the turbocharger 21 in the prior application is actually not the entire area of the normal operation area in FIG. 4 but only a partial area on the side where the corrected flow rate is small and the pressure ratio is small. However, in the present invention, the entire normal operation range is used. For this reason, when setting a region where the corrected flow rate is large and the pressure ratio is large as a new use region, it is necessary to consider the difference in exhaust temperature from the use region used up to that point. Things.
[0059]
The correction part of the above 2) is a basic correction part comprising an actual supercharging pressure calculation part 64, an actual exhaust displacement calculation part 65, a correction amount basic value calculation part 66 at the time of abnormal operation, and an addition part 70; It is divided into an auxiliary correction part comprising a time correction coefficient calculation part 68 and a multiplication part 69.
[0060]
Here, the basic correction portion sets the basic value Rvnt0 to the ratio of the opening of the variable nozzle 24 when it is determined that the turbocharger is in a transient abnormal operation based on the actual supercharging pressure and the actual displacement. This is a portion that corrects to an increase side (a side where the capacity of the turbocharger increases). The auxiliary correction portion is provided as a measure for racing.
[0061]
More specifically, the actual boost pressure calculating section 64 calculates the actual boost pressure Pm from the signal of the boost pressure sensor 36.
[0062]
The actual displacement calculating unit 65 calculates the cylinder intake air amount Qac and the target fuel injection amount Qsol from
Qexh = (Qac + Qsol × GKQFVNT #) × Ne / KCON # (13)
Here, GKQFVNT #: conversion coefficient,
KCON #: constant,
The actual displacement Qexh [g / sec] is calculated by the following equation. The expression (13) is the same as the expression (2).
[0063]
The abnormal operation correction amount basic value calculation unit 66 searches the map having the contents shown in FIG. 5 from the actual exhaust gas amount Qexh and the actual supercharging pressure Pm, thereby obtaining the abnormal operation correction amount basic value TRAVOB0 [%] (control Is calculated.
[0064]
The basic value TRAVOB0 is used to quickly return to the normal operation range when the operating point of the entire turbocharger jumps into the abnormal operation range.
[0065]
The normal operation range and the abnormal operation range of the compressor 23 are determined from the characteristics shown in FIG. That is, FIG. 4 shows the characteristics of the compressor efficiency with the corrected flow rate on the horizontal axis and the pressure ratio on the vertical axis. The shaded portion indicates the normal operation range, and the outside portion indicates abnormal operation in which surge, choke, and turbine overspeed occur. Area.
[0066]
The compressor 23 needs to operate in the shaded normal operating range, but transiently jumps into the abnormal operating range outside the normal operating range. For example, if the opening ratio of the variable nozzle 24 is transiently delayed from increasing, the actual gas flow rate Q passing through the compressor increases, and choking occurs. Not only in the case of choking, but also in the case of surge or turbine overspeed, in order to return to the normal operation range, correction may be made to the side where the supercharging pressure decreases (the side where the opening ratio of the variable nozzle 24 increases).
[0067]
That is, the correction region is the entire abnormal operation region. The corrected flow rate Q * on the horizontal axis in FIG. 4 is a value obtained by correcting the actual gas flow rate Q passing through the compressor 23 by the gas temperature T1 and the gas pressure P1 (C1 and C2 are constants). As the gas flow rate Q, a cylinder intake air amount Qac can be used. On the other hand, the pressure ratio on the vertical axis in FIG. 4 is the ratio between the actual supercharging pressure Pm and the atmospheric pressure Pa, and the atmospheric pressure Pa does not change so much. Therefore, only the actual supercharging pressure Pm may be considered for the time being. Therefore, it is possible to determine whether or not the operating point of the compressor 23 is in the abnormal operating range by using the cylinder intake air amount Qac and the actual supercharging pressure Pm as parameters.
[0068]
In fact, the efficiency of the turbocharger is the total efficiency of the compressor efficiency and the turbine efficiency. Therefore, when considering whether or not the entire turbocharger is in the abnormal operation range, only the compressor 23 needs to be considered. Instead, the turbine 22 must be considered. Therefore, when an experiment was conducted to determine what parameters are optimal for determining whether or not the engine is in the abnormal operation range as a whole turbocharger, it is better to use the actual displacement Qexh instead of Qac. That is, it has been found that when the actual supercharging pressure Pm and the actual displacement Qexh are used as parameters, it is easy to grasp whether or not the entire turbocharger is in an abnormal operation range.
[0069]
Therefore, the present invention determines whether or not the entire turbocharger is in an abnormal operation range using the actual displacement Qexh [g / sec] and the actual supercharging pressure Pm as parameters as shown in FIG. That is, in FIG. 5, the central region is a normal operation region, and a small region outside the central region is an abnormal operation region. Since it is not necessary to provide a correction amount in the normal operation range, the correction amount basic value TRAVOB0 is zero, whereas a positive value is included in the abnormal operation range. Further, the value of TRAVOB0 increases as the operating point of the turbocharger determined from the actual supercharging pressure and the actual exhaust flow rate departs from the normal operation range.
[0070]
As will be described later, since the correction amount basic value TRAVOB0 is added to the above-described target opening ratio Rvnt1 of the variable nozzle, the positive correction amount basic value TRAVOB0 increases the opening ratio of the variable nozzle 24 (the boost pressure decreases). Side).
[0071]
Although it can be read from FIG. 5 that the boundary between the normal operation area and the abnormal operation area is clear, it is not actually the case but only the boundary obtained by estimation. In FIG. 5, a pressure ratio or an actual exhaust pressure may be used instead of the actual supercharging pressure on the vertical axis. Further, it goes without saying that, in the region enclosed by the maximum flow rate and the upper limit supercharging pressure in FIG. 5, the ratio of closing the normal operation region differs depending on the combination of the engine and the turbocharger.
[0072]
The subtraction unit 67 obtains the difference (Qac-tQac) between the cylinder intake air amount Qac as the actual intake air amount and the target intake air amount tQac, and the abnormal operation correction coefficient calculation unit 68 makes FIG. The abnormal operation correction coefficient KTRAVOB is calculated by searching the table.
[0073]
The correction coefficient KTRAVOB is introduced to deal with racing. Racing is an operation of repeatedly depressing and releasing the accelerator pedal, and repeatedly depressing and releasing the accelerator pedal. The movement of tQac at this time may be, for example, a sine curve having a constant period, and the movement of Qac may be a sine curve having a phase delay with respect to the sine curve. Is maximized when it matches the amplitude of the sine curve. As described above, when Qac becomes larger than tQac, it means that the actual supercharging pressure exceeds the target and becomes too high. That is, also at this time, the operating point of the turbocharger 21 may jump into the abnormal operation range.
[0074]
Therefore, in a region where the value of Qac-tQac is large as shown in FIG. 6, a value larger than 1.0 (for example, about 1.2) is given as the correction coefficient KTRAVOB to increase the opening ratio of the variable nozzle 24 (see FIG. 6). (The side where the supercharging pressure decreases).
[0075]
In FIG. 6, an area (dead zone) where the correction coefficient KTRAVOB is 1.0 is provided in an area where the value of Qac-tQac is equal to or smaller than the predetermined value A.
[0076]
here,
Error ratio [%] = (Qac / tQac−1) × 100 (14)
When the error ratio is defined by the following equation, the predetermined value A is determined so that the error ratio is about 20%. The reason why the correction is not performed at less than 20% (correction coefficient KTRAVOB = 1.0) is to avoid interference with feedback control of the aperture ratio. That is, the feedback amount Avnt of the opening ratio　Since fb is limited so that the error ratio of equation (14) works within a range of ± 10%, a positive correction coefficient KTRAVOB is given even when the error range of equation (14) is in the range of 0 to 10%. This is because it interferes with the feedback control.
[0077]
The multiplication unit 69 calculates a value obtained by multiplying the abnormal operation correction coefficient KTRAVOB thus calculated by the abnormal operation correction amount basic value TRAVOB0 as the abnormal operation correction amount TRAVOB, and the addition unit 70 calculates the target opening ratio Rvnt1. Then, a value obtained by adding the abnormal operation time correction amount TRAVOB to the target opening ratio Rvnt is calculated.
[0078]
Here, the operation of the present embodiment will be described with reference to FIG. FIG. 7 shows, for example, that the accelerator pedal is depressed and increased at the timing of t1 to accelerate the vehicle from the state of traveling at a constant speed of 60 km / h and reaches 100 km / h at the timing of t2. In the case (the gear of the transmission is fixed to the fourth speed), each change of the accelerator pedal, the vehicle speed, the supercharging pressure, and the final command opening ratio Trvnt of the variable nozzle 24 is modeled.
[0079]
In the lowermost stage, a change in the final command opening ratio Trvnt by the prior application when the time from t1 to t2 is constantly and slowly changed is indicated by a solid line for comparison. It is practically impossible to change the opening ratio of the variable nozzle 24 transiently in this way.
[0080]
According to the present embodiment, when the accelerator pedal and the vehicle speed change as shown in the first and second stages of FIG. 7, the final command opening ratio Trvnt changes as indicated by the one-dot chain line at the bottom.
[0081]
That is, when the accelerator pedal is further depressed at t1, the target supercharging pressure (see the solid line) rises in a stepwise manner as shown in the third stage, while on the other hand, the fuel is increased by the further depression of the accelerator pedal, and the exhaust amount increases. Since the turbine speed increases in response to the displacement, the actual supercharging pressure Pm (see the broken line) increases and follows the target value.
[0082]
This movement is the same even if the target supercharging pressure is replaced with the target intake air amount tQac and the actual supercharging pressure Pm is replaced with the cylinder intake air amount Qac. This is because the target intake air amount tQac is originally determined so as to obtain the target boost pressure. Accordingly, at t1, the target intake air amount tQac rises in a stepwise manner, and the cylinder intake air amount Qac using this target value as the actual value follows.
[0083]
In order to compensate for the response delay of the cylinder intake air amount Qac at this time, the advance process works. This is handled by the advance processing units 47 and 53 in FIG. For this reason, the final command opening ratio Trvnt decreases stepwise, and thereafter returns to the side that gradually increases. In this advance process, the actual supercharging pressure (Qac) rapidly rises because the turbine rotation increases even though the displacement is the same (see the third stage).
[0084]
In this case, if the variable nozzle 24 has a response delay toward the side where the opening ratio becomes large, the actual supercharging pressure Pm rises rapidly, and the operating point of the turbocharger 21 jumps into an abnormal operation range, causing choking and turbine operation. According to the present embodiment, the actual supercharging pressure Pm is monitored by the supercharging pressure sensor 36 and the actual exhaust amount Qexh is calculated. It is determined based on the actual supercharging pressure Pm and the actual displacement Qexh whether or not the operating point of the turbocharger 21 has jumped into the abnormal operation range. Then, when it is determined that the operating point of the turbocharger 21 has jumped into the abnormal operating range, the target opening ratio Rvnt1 is corrected to be larger, so that the final opening ratio Rvnt1 is larger than that of the prior application by the amount of this correction. The command opening ratio Trvnt moves to a side where the command opening ratio Trvnt increases, whereby the operating point of the turbocharger 21 is promptly returned to the normal operation range. The correction during the abnormal operation is performed by the abnormal operation correction amount basic value calculation unit 66 and the addition unit 70 in FIG.
[0085]
Since the correction amount basic value TRAVOB0 is given only in the abnormal operating range of the turbocharger in FIG. 5, the operating point of the turbocharger 21 jumps into the abnormal operating range as described above. Then the correction is supposed to work. Therefore, in the third stage of FIG. 7, the actual supercharging pressure should exceed the target supercharging pressure, but it is not drawn.
[0086]
This is because the correction amount basic value TRAVOB0 having a positive value is actually given also in the vicinity of the abnormal operating range of the turbocharger (that is, in the normal operating range near the abnormal operating range). Since the correction starts to work in the normal operation region near the abnormal operation region, it is possible to prevent the turbocharger from becoming transient abnormal operation. This result shows that the actual supercharging pressure Pm approaches the target supercharging pressure but does not exceed the target supercharging pressure as shown in the third row.
[0087]
After the actual supercharging pressure approaches the target supercharging pressure, the actual supercharging pressure gradually decreases away from the target supercharging pressure. At this time, when the actual intake air amount Qac approaches the target intake air amount delay processing value tQacd and the error ratio falls within ± 10%, feedback control of the opening ratio operates, and Qac changes the target intake air amount delay processing value. It quickly converges to tQacd (therefore, the actual supercharging pressure Pm to the target supercharging pressure). This feedback control is performed by the cylinder intake air amount calculation unit 48, the delay processing unit 49, the subtraction unit 50, the opening ratio feedback amount calculation unit 51, and the addition unit 52 in FIG.
[0088]
In the feedback control, when the target intake air amount tQac is used as the target value, the ability of Qac to follow tQac after the actual supercharging pressure approaches the target supercharging pressure is poor, so that the actual supercharging pressure becomes higher than the target supercharging pressure. Although the supply pressure deviates greatly and causes smoke and knocking noise, in the present embodiment, the delay processing value tQacd is used instead of the target intake air amount tQac. Therefore, even when the actual boost pressure approaches the target boost pressure and then decreases away from the target boost pressure, the drop does not drop significantly.
[0089]
Also, when the accelerator pedal is released at the timing of t2, the target boost pressure decreases stepwise, and the actual boost pressure Pm follows this target boost pressure with a response delay. An advance process is performed to compensate for a response delay of the supply pressure (therefore, the cylinder intake air amount Qac). This is handled by the advance processing units 47 and 53 in FIG.
[0090]
As described above, in the present embodiment, the follow-up process and the feedback control adopted in the present embodiment at the time of accelerating with the accelerator pedal depressed further increase the followability to the target supercharging pressure (or the target intake air amount) satisfactorily. The abnormal operation of the turbocharger 21 can be positively avoided by the abnormal operation correction added in the present invention while maintaining the same.
[0091]
In the case where the operating point of the turbocharger 21 transiently jumps into the abnormal operating range, not only during acceleration but also according to the present embodiment (the invention according to claim 2), based on the actual supercharging pressure and the actual exhaust flow rate. Therefore, it is determined whether or not the turbocharger is in a transient abnormal operation or in a state immediately before the transient abnormal operation, so that the determination accuracy is improved. According to the good judgment result, the target opening ratio Rvnt1 (control amount) is set to the side where the capacity of the turbocharger increases in the transient abnormal operation of the turbocharger or immediately before the transient abnormal operation. By correcting, even if a transient abnormal operation of the turbocharger occurs, it can be quickly returned to the normal operation, or the normal operation immediately before the transient abnormal operation of the turbocharger can be performed. Can be stopped.
[0092]
In the embodiment, it is determined whether or not the turbocharger is in a transient abnormal operation or is in a state immediately before the transient abnormal operation based on the actual supercharging pressure and the actual exhaust flow rate. As described above, based on the actual supercharging pressure and the actual gas flow rate passing through the compressor, whether or not the compressor is in a transient abnormal operation or is in a state immediately before the transient abnormal operation. May be determined (the invention according to claim 1).
[0093]
Also, as in racing, when the actual intake air amount Qac becomes larger than the target intake air amount tQac by a predetermined value A or more, the operating point of the turbocharger may jump into the abnormal operation range. However, according to the present embodiment (the invention according to claim 11), when tQac is larger than tQac by a predetermined value A or more, the opening ratio of the variable nozzle is further increased (for the turbocharger). Since the abnormal operation correction amount basic value TRAVOB0 is corrected to the side where the capacity is further increased), it is possible to prevent the operating point of the turbocharger from jumping into the abnormal operation range due to such racing.
[0094]
According to the present embodiment (the invention according to claim 14), the target opening ratio basic value Rvnt0 (control amount) is set in the EGR operating range based on the target exhaust flow rate tQexh and the target EGR rate Megr. In the operating range of, the target opening ratio basic value Rvnt0 can be accurately set, and the control performance of the supercharging pressure can be further improved.
[0095]
Turbo efficiency (combined efficiency of compressor efficiency and turbine efficiency) is greatly affected not only by the exhaust flow rate but also by the exhaust temperature. In the prior application, the exhaust flow rate is set as a parameter for setting the target opening ratio (control amount). Since only (tQexh) is used, it cannot respond to a difference in exhaust gas temperature. For example, if the target opening ratio is matched to the exhaust temperature on the low load side, and if the actual exhaust temperature becomes higher than the exhaust temperature used for matching the target opening ratio when the load becomes high, the temperature difference Therefore, there is a possibility that the turbocharging pressure is increased and the supercharging pressure is increased. On the other hand, according to the present embodiment (the invention according to claim 15), the load correction value calculation unit 62 and the addition unit 63 determine the temperature difference by the target fuel injection amount Qsol as the exhaust gas temperature substitute value. Since the target opening ratio is corrected to the side where the capacity of the turbocharger is increased by the increase in the turbo efficiency, over-boost can be prevented even when the load becomes high.
[0096]
The actuator 25 of the present embodiment has a non-linear characteristic in the duty value with respect to the opening ratio (control amount), and also has a hysteresis in which the duty value differs between when the opening ratio is increasing and when it is decreasing. However, according to the present embodiment (the invention according to claim 19), since the non-linearity and hysteresis of the actuator 25 are compensated, the turbocharger is abnormal due to the use of the actuator 25 having large hysteresis. It is possible to prevent entry into driving.
[0097]
The correspondence between this embodiment and the components of the invention described in claim 2 is as follows. The abnormal operation correction amount basic value calculation unit 66 of FIG. 3 performs the function of the abnormal operation determination unit, and the abnormal operation correction amount basic value calculation unit 66 and the addition unit 70 of FIG. 3 also perform the function of the control amount correction unit. Play.
[0098]
In the embodiment, the turbocharger in which the supercharging pressure changes according to the opening ratio of the variable nozzle has been described. However, the present invention is not limited to this, and may be applied to the following. That is, in the turbine, the charging pressure changes if the area through which the gas passes changes, so that the charging pressure changes even if the opening ratio of the scroll or the diffuser is changed in addition to the nozzle. Since these can eventually change the geometry of the turbine, they are collectively referred to as a variable geometric turbocharger (Variable @ GeometricTurbocharger). The present invention has application to such variable geometric turbochargers. Further, the present invention is also applicable to a turbocharger having a constant capacity provided with a wastegate valve. In the variable geometric turbocharger, for example, the control value is a target value of the opening area of the turbine or a value corresponding to the opening area, and the target value of the turbocharger of a fixed capacity including the wastegate valve, for example, the target value of the valve opening is the control amount.
[Brief description of the drawings]
FIG. 1 is a control system diagram of one embodiment.
FIG. 2 is a schematic block diagram of cooperative control of supercharging pressure control and EGR control in the prior application device.
FIG. 3 is a detailed block diagram of a target opening ratio calculation unit.
FIG. 4 is a characteristic diagram of compressor efficiency.
FIG. 5 is a characteristic diagram of an abnormal operation correction amount basic value.
FIG. 6 is a characteristic diagram of a correction coefficient during abnormal operation.
FIG. 7 is a waveform chart for explaining the operation of the embodiment at the time of transition.
FIG. 8 is a waveform chart in the case of a control object having a large dead time and a large response time constant.
[Explanation of symbols]
21 turbocharger
22 turbine
23 compressor
24 ° variable nozzle (geometry variable mechanism)
31 engine controller
35 ° air flow meter
36 supercharging pressure sensor

Claims (20)

A variable-capacity turbocharger having a geometry variable mechanism that can change the geometry of the turbine in response to a control amount,
In a control device of a turbocharger comprising a control amount setting means for setting the control amount to the geometry variable mechanism,
At the time of abnormal operation which determines whether or not the compressor is in a transient abnormal operation or is in a state immediately before the transient abnormal operation based on the actual supercharging pressure and the actual gas flow rate passing through the compressor. Determining means;
Control amount correction means for correcting the control amount on the side where the capacity of the turbocharger increases in the state immediately before the transient abnormal operation or the transient abnormal operation of the intake compressor based on the determination result. A control device for a turbocharger, characterized in that: A variable-capacity turbocharger having a geometry variable mechanism that can change the geometry of the turbine in response to a control amount,
In a control device of a turbocharger comprising a control amount setting means for setting the control amount to the geometry variable mechanism,
Abnormal operation determination based on the actual supercharging pressure and the actual exhaust gas flow to determine whether the turbocharger is in a transient abnormal operation or in a state immediately before the transient abnormal operation. Means,
Control amount correction means for correcting the control amount to a side where the capacity of the turbocharger increases in the transient abnormal operation of the turbocharger or immediately before the transient abnormal operation based on the determination result. A control device for a turbocharger, comprising: A constant-capacity turbocharger that can change the opening of the wastegate valve in response to the control amount,
A control amount setting means for setting the control amount to the wastegate valve;
Abnormal operation that determines whether the intake compressor is in a transient abnormal operation or is in a state immediately before the transient abnormal operation based on the actual supercharging pressure and the actual gas flow rate passing through the compressor. Time determination means,
Control amount correction means for correcting the control amount on the side where the degree of opening of the wastegate valve increases in the state immediately before the transient abnormal operation or the transient abnormal operation of the intake compressor based on the determination result. A control device for a turbocharger, characterized in that: A constant-capacity turbocharger that can change the opening of the wastegate valve in response to the control amount,
A control amount setting means for setting the control amount to the wastegate valve;
Abnormal operation time determination means for determining whether or not the turbocharger is in a transient abnormal operation state based on the actual supercharging pressure and the actual exhaust flow rate, or whether it is in a state immediately before the abnormal operation state,
Control amount correction means for correcting the control amount on the side where the degree of opening of the wastegate valve increases in the state immediately before the transient abnormal operation or the transient abnormal operation of the intake compressor based on the determination result. A control device for a turbocharger, characterized in that: The transient abnormal operation of the compressor is a time when the operating point of the compressor determined by the actual supercharging pressure and the actual gas flow rate flowing through the compressor is in an abnormal operation range of the compressor. 3. The control device for a turbocharger according to claim 1. The state immediately before the transient abnormal operation of the compressor is that the operating point of the compressor determined from the actual supercharging pressure and the actual gas flow rate flowing through the compressor is in a normal operating range near the abnormal operating range of the compressor. The control device for a turbocharger according to claim 1 or 3, wherein: The transient abnormal operation of the turbocharger is characterized in that the operating point of the turbocharger determined from the actual supercharging pressure and the actual exhaust flow rate is in an abnormal operation range of the turbocharger. The control device for a turbocharger according to claim 2 or 4, wherein Immediately before the transient abnormal operation of the turbocharger, the operating point of the turbocharger determined from the actual supercharging pressure and the actual exhaust flow rate is in the normal operating range near the abnormal operating range of the turbocharger. The control device for a turbocharger according to claim 2 or 4, wherein the control is at a certain time. 7. The turbocharger according to claim 5, wherein the correction value of the control amount is increased as the operating point of the compressor determined from the actual supercharging pressure and the actual gas flow rate passing through the compressor departs from the normal operation range. Feeder control device. The turbocharger according to claim 7 or 8, wherein the correction value of the control amount is increased as the operating point of the turbocharger determined from the actual supercharging pressure and the actual exhaust flow rate departs from a normal operation range. Machine control device. A target intake air amount calculating means for calculating a target intake air amount, and an actual intake air amount calculating means for calculating an actual intake air amount, when the actual intake air amount becomes larger than a target intake air amount by a predetermined value or more. The turbocharger control device according to claim 1 or 2, wherein the control amount is corrected so that the capacity of the turbocharger further increases. A target intake air amount calculating means for calculating a target intake air amount, and an actual intake air amount calculating means for calculating an actual intake air amount, when the actual intake air amount becomes larger than a target intake air amount by a predetermined value or more. 5. The turbocharger control device according to claim 3, wherein the control amount is corrected so that the opening of the wastegate valve further increases. The control device for a turbocharger according to any one of claims 1 to 4, wherein the control amount is set based on a target exhaust flow rate and an engine load in a non-operating region of EGR. The control device for a turbocharger according to any one of claims 1 to 4, wherein the control amount is set based on a target exhaust flow rate and a target EGR rate in an EGR operation range. 15. The control device for a turbocharger according to claim 13, wherein the control amount is corrected by an exhaust gas temperature. The control device for a turbocharger according to claim 15, wherein a fuel injection amount is used instead of the exhaust gas temperature. 15. The turbocharger according to claim 13, wherein a feedback amount of the control amount is calculated so that an actual intake air amount matches a target intake air amount, and the control amount is corrected by the feedback amount. Feeder control device. The control device for a turbocharger according to claim 17, wherein a delay processing value is used instead of the target intake air amount. The geometry variable mechanism includes a variable nozzle of a turbine and an actuator that drives the variable nozzle, and the actuator has a non-linear characteristic in the duty value with respect to the control amount, and when the control amount tends to increase. 3. The control device for a turbocharger according to claim 1 or 2, wherein when the duty value has a hysteresis different from that when the duty value is decreasing, the nonlinearity and the hysteresis of the actuator are compensated. . The control variable is a variable nozzle opening or a variable nozzle opening ratio when the geometry variable mechanism includes a variable nozzle of an exhaust turbine and an actuator for driving the variable nozzle. Or the control device of the turbocharger according to 2.

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