JP2010242722A - Turbocharger driving control method and device thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve stability and reliability, by surely avoiding an excessive increase in unnecessary boost pressure in an automatic vehicle. <P>SOLUTION: When a shifting gear of an automatic transmission 8 is shifted down by a gear in a position except for neutral and parking (S204 and S206), when torque or a fuel injection quantity exceeds a predetermined torque value or a predetermined fuel injection quantity (S208) and a vehicle speed exists in a state of exceeding a predetermined vehicle speed (S210), while stopping a PID arithmetic operation of PID control in feedback control by PID control of supercharging pressure for a predetermined stopping time (S214-S218), subtraction of a predetermined value is applied to a control valve in feedforward control of the supercharging pressure, and a subtraction value is gradually reduced to zero (S220-S226), so that the excessive increase in the unnecessary boost pressure can be surely avoided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a drive control method and apparatus for a turbocharger used in an internal combustion engine, and more particularly, to an improvement in safety and reliability in a vehicle equipped with an automatic transmission.

A turbine is provided in an exhaust passage of an internal combustion engine such as a diesel engine, and this is rotated by the flow of exhaust gas to obtain a rotational driving force. A compressor disposed in the intake passage is driven by the rotational driving force to Various turbochargers (superchargers) configured to forcibly send air into an engine have been proposed and put into practical use as effective means for measures against emissions of internal combustion engines.
In recent years, a variable turbocharger that can adjust the turbine efficiency and control the supercharging pressure by using a variable turbine provided with a vane that can change the angle with respect to the flow of exhaust gas has been widely adopted. (See, for example, Patent Document 1).

JP 2008-169758 A (page 4-10, FIGS. 1 to 6)

Such a turbocharger is mounted not only on a so-called manual vehicle but also on an automatic vehicle equipped with an automatic transmission, but the automatic vehicle may cause the following specific problems.
In other words, in a situation where the downshift of the transmission gear is performed in an automatic vehicle and the engine speed increases while the engine torque is maintained substantially constant, for example, when the downshift is performed during uphill driving, etc. There is a possibility that the turbocharger cannot fully perform its function, for example, the boost pressure increases to a level larger than necessary and causes the exhaust gas performance to deteriorate.
Such excessive increase of the unnecessary boost pressure includes an increase in turbo efficiency due to an increase in back pressure in the turbocharger, an increase in target boost pressure, an increase in duty output of boost pressure increase control by PID learning processing in turbo control, and the like. It is thought that there is a cause for the overlap.

  The present invention has been made in view of the above circumstances, and provides a turbocharger drive control method and apparatus thereof that reliably avoids an excessive increase in unnecessary boost pressure in an automatic vehicle and has high stability and reliability. Is.

In order to achieve the above object of the present invention, a turbocharger drive control method according to the present invention comprises:
A turbocharger drive control method in a turbocharger drive control device that is mounted on a vehicle having an automatic transmission and configured to be capable of varying a supercharging pressure,
When the shift gear of the automatic transmission is gear-shifted down at a position other than neutral and parking, the torque or fuel injection amount exceeds a predetermined torque value or a predetermined fuel injection amount, and the vehicle speed reaches a predetermined vehicle speed. If you are over
During the predetermined stop time
While stopping the PID calculation of the PID control in the feedback control by the PID control of the supercharging pressure,
A predetermined value is subtracted from the control value in the feedforward control of the supercharging pressure, and the subtracted value is gradually reduced to zero.
In order to achieve the above object of the present invention, a turbocharger drive control device according to the present invention includes:
It is mounted on a vehicle having an automatic transmission, and has a turbocharger and an electronic control unit that controls the operation of the turbocharger, and is configured to be able to control the supercharging pressure by the operation control of the turbocharger. A turbocharger drive control device comprising:
The electronic control unit is
It is determined that the gear for shifting of the automatic transmission has been gear-shifted down at a position other than neutral and parking, the torque or fuel injection amount exceeds a predetermined torque value or a predetermined fuel injection amount, and the vehicle speed reaches a predetermined vehicle speed. When it ’s determined that it ’s exceeded,
During a predetermined stop time, while stopping the PID calculation of the PID control in the feedback control by the PID control of the supercharging pressure,
A predetermined value is subtracted from the control value in the feedforward control of the supercharging pressure, and the subtracted value is gradually reduced to zero.

  According to the present invention, an excessive increase in boost pressure is reliably suppressed even in a conventional driving situation that causes an excessive increase in boost pressure that deteriorates exhaust gas performance in an automatic vehicle. The turbocharger drive control method and apparatus with high stability and reliability can be provided.

It is a block diagram which shows the structural example of the turbocharger drive control apparatus with which the turbocharger drive control method in embodiment of this invention is applied. 2 is a subroutine flowchart showing an outline of a basic procedure of turbocharger drive control processing executed by an electronic control unit of the turbocharger drive control apparatus shown in FIG. 1. FIG. 3 is a characteristic diagram showing switching characteristics of operation / non-operation characteristics of a turbocharger in the turbocharger drive control process shown in FIG. 2. FIG. 3 is a subroutine flowchart showing a first half of a procedure of turbocharger drive control processing executed by an electronic control unit of the turbocharger drive control apparatus shown in FIG. 1 in the embodiment of the present invention. FIG. 3 is a subroutine flowchart showing a second half part of a procedure of turbocharger drive control processing in the embodiment of the present invention executed by an electronic control unit of the turbocharger drive control apparatus shown in FIG. 1. It is a schematic diagram which illustrates typically the change of the feedforward value and PID control value by execution of the turbocharger drive control processing of embodiment of this invention. It is a schematic diagram which illustrates typically the change of the feedforward value and PID control value by execution of the turbocharger drive control processing of embodiment of this invention, Comprising: The actual pressure reached the target pressure especially in the learning stop state It is a schematic diagram for demonstrating the mode in a case. It is a schematic diagram for demonstrating operation | movement of the conventional turbocharger drive control equipment.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8.
The members and arrangements described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.
Initially, the structural example of the turbocharger drive control apparatus in embodiment of this invention is demonstrated, referring FIG.
In the embodiment of the present invention, the turbocharger 1 is a so-called variable turbocharger, and although not shown, a variable turbine (not shown) having a vane (not shown) whose angle with respect to the flow of exhaust gas can be adjusted. And a compressor (not shown) that is rotationally driven by the rotational driving force of the variable turbine and pumps intake air.

The vane (not shown) is provided with a negative pressure turbo actuator (indicated as “T-ACT” in FIG. 1) 2 so that the angle with respect to the flow of the exhaust gas can be adjusted.
Exhaust gas from an engine 3 as an internal combustion engine typified by a diesel engine is exhausted through a turbocharger 1, while intake air is taken in through an intake manifold (“IN-MANI” in FIG. 1). And 4).

On the other hand, a negative pressure tank 6 is provided for introducing negative pressure to the turbo actuator 2 and an electromagnetic vacuum adjusting valve (in FIG. 1) is used to control the amount of negative pressure introduced from the negative pressure tank 6 to the turbo actuator 2. Is indicated as “EVRV”) 5.
The operation of the electromagnetic vacuum adjusting valve 5 is controlled by an electronic control unit (indicated as “ECU” in FIG. 1) 7 (details will be described later).

The electronic control unit 7 includes a microcomputer (not shown) having a known and well-known configuration, a storage element (not shown) such as a RAM and a ROM, and an input / output interface circuit (see FIG. (Not shown) as a main component.
The electronic control unit 7 is configured to execute various software necessary for operation control of the engine 3, and performs turbocharger drive control processing described later as one of the control processing. Yes.

The electronic control unit 7 includes an output signal from the atmospheric pressure sensor 11, an output signal from the rotation sensor 12 that detects the number of revolutions of the engine 3, and an output from the vehicle speed sensor 13 that detects the vehicle speed for the above-described control processing. In addition to a signal, an output signal of a water temperature detection sensor 14 for detecting the coolant temperature of the engine cooling water, an output signal of an intake pressure sensor 15 for detecting the intake pressure sucked into the intake manifold 4, etc. Various signals necessary for operation control necessary for the operation of the vehicle are input and used for various operation control processes of the vehicle.
.
The electronic control unit 7 outputs an intake air compression ratio control signal as an operation control signal to the electromagnetic vacuum adjustment valve 5 by executing a turbocharger drive control processing software, which will be described later, and controls its operation. ing.

  That is, the electromagnetic vacuum adjusting valve 5 has its valve opening controlled by the electronic control unit 7, and the amount of negative pressure introduced to the turbo actuator 2 is changed by adjusting the valve opening. The change in the amount of negative pressure introduced to the turbo actuator 2 changes the angle of the vane (not shown) with respect to the exhaust gas flow, thereby changing the rotational efficiency of the variable turbine (not shown), and the compressor (see FIG. The compression rate of the intake air by (not shown) can be changed.

  The vehicle in the embodiment of the present invention is a so-called automatic vehicle equipped with an automatic transmission 8 (indicated as “AT” in FIG. 1), and the operation control of the automatic transmission 8 is also executed by the electronic control unit 7. Has become.

FIG. 2 shows a subroutine flowchart showing an outline of a basic procedure of turbocharger drive control processing executed by the electronic control unit 7, and the processing contents will be described below with reference to FIG.
When the processing by the electronic control unit 7 is started, first, it is determined whether or not the target injection amount Qt exceeds a predetermined threshold value Qth up that requires control of the supercharging pressure (boost pressure) by the turbocharger 2. (See step S102 in FIG. 2).
The above-mentioned threshold value as a reference for determining whether or not turbocharger drive control is necessary is dynamically determined from, for example, a predetermined arithmetic expression or map based on the engine speed and the gear ratio. It is preferable that it is calculated.

  In the embodiment of the present invention, the electronic control unit 7 controls the operation of the engine 3. Therefore, data such as the target fuel injection amount and the gear ratio are stored in the engine control unit. The result of the software execution process can be diverted. Therefore, there is no need to calculate the target fuel injection amount in step S102, and no special processing for determining the gear ratio is required.

Here, in the embodiment of the present invention, a so-called hysteresis is provided as a threshold for determining whether or not the target injection amount requires control of the supercharging pressure from the viewpoint of ensuring operational stability. The value Qth up is the upper threshold value.
When it is determined in step S102 that the target injection amount Qt exceeds the threshold value Qth up (in the case of YES), the process proceeds to the processing of step S104 described below, while the target injection amount Qt is the threshold value. If it is determined that Qth up is not exceeded (in the case of NO), the process proceeds to step S106 described later.

In step S104, boost pressure control output is calculated.
In other words, the magnitude of the control signal for the electromagnetic vacuum adjusting valve 5 is calculated.
In the embodiment of the present invention, when the process proceeds to step S104 in response to the determination that the target injection amount Qt has exceeded the threshold value Qth up in the previous step S102, the boost pressure control output On the other hand, feedback control and feedforward control by PID control are performed.

In the embodiment of the present invention, as shown in FIG. 3 as an example, a region where boost pressure control is performed only by feedforward control using the engine speed and the target injection amount as parameters (the shaded portion in FIG. 3). Reference) and a region controlled by using both feedback control and feedforward control.
As described above, when the feedforward control only is used, when the feedforward control and the feedback control are used in combination, and when the engine speed and the target injection amount are used as parameters, two control modes are used in the low load region. As the air pressure becomes unstable, the supercharging pressure correlated with the engine exhaust pressure also becomes unstable. For this reason, it is necessary to avoid feedback control based on an unstable supercharging pressure.

When boost pressure control is performed by using this feedback control and feedforward control together, the P term, I term, and D term obtained by PID control are added to the boost pressure control output determined by feedforward control. The calculation result is the boost pressure control output in step S104.
On the other hand, in step S106, the boost pressure control output is a value determined by feedforward control.

After execution of the process of step S104 or step S106, the process proceeds to the process of step S108, and the boost pressure control output limiting process is executed.
That is, first, from the viewpoint of ensuring stable engine operation and the like, a predetermined arithmetic expression or map set in advance based on the engine speed, the fuel injection amount, and the total fuel consumption from the start of the engine start. Thus, an upper limit value and a lower limit value for limiting the boost pressure control output are calculated.

Next, output restriction is executed as described below by comparing the boost pressure control output calculated in the previous step S104 or step S106 with these upper limit values or lower limit values.
That is, when the boost pressure control output calculated in the previous step S104 or step S106 is smaller than the above lower limit value, the final boost pressure control output is set to the lower limit value.

When the boost pressure control output calculated in the previous step S104 or step S106 is larger than the above upper limit value, the final boost pressure control output is set to the upper limit value.
When the boost pressure control output calculated in the previous step S104 or step S106 is in a range smaller than the above upper limit and larger than the above lower limit, the calculated boost pressure control. The output is supposed to be the final output.

  In the embodiment of the present invention, the operation of the electromagnetic vacuum adjustment valve 5 is controlled by PWM control, i.e., so-called duty ratio control that changes the width of the pulse signal with respect to the repetition period. The valve opening state of the electromagnetic vacuum adjusting valve 5 is variable. Therefore, the boost pressure control output for the electromagnetic vacuum adjusting valve 5 is a so-called duty output.

  After the execution of step S108 as described above, the process once returns to the main routine (not shown), the operation of the electromagnetic vacuum adjustment valve 5 is controlled by the boost pressure control output determined in step S108, and the turbocharger 1 performs supercharging. The pressure is set according to the operation.

  As described above, the vehicle in the embodiment of the present invention is premised on a so-called automatic vehicle equipped with the automatic transmission 8, and is based on the turbocharger drive control described above, and has a boost pressure control unique to the automatic vehicle. In order to solve the above problem, the turbocharger drive control process shown in the subroutine flowcharts of FIGS. 4 and 5 is executed by the electronic control unit 7.

Here, when explaining the turbocharger drive control processing in the embodiment of the present invention shown in the subroutine flowcharts of FIGS. 4 and 5, the problem in the specific boost pressure control that has occurred in the conventional automatic vehicle will be described. The description will be made with reference to FIG.
First, in a conventional automatic vehicle equipped with a turbocharger, for example, when the vehicle is running uphill, and a gear shift down (not shown) is performed, the engine speed is represented by g4-8 in FIG. As shown, the rotational speed increases corresponding to the gear shift. In FIG. 8, the characteristic line denoted by g5-8 schematically represents the occurrence of gear shift down, and time t1 is the time when gear shift down occurs.

As a result of this gear shift down, in the conventional turbo pressure control processing of an automatic vehicle, the target boost pressure increases (see the characteristic line labeled g2-8 in FIG. 8), and the boost control value, specifically, PID The learning value in the learning control increases (see the characteristic line labeled g1-8 in FIG. 8). Therefore, the actual boost pressure also rises following this, but shows a change that reaches the target boost pressure by causing overshoot and undershoot across the target boost pressure (FIG. 8). (See characteristic line labeled g2-8).
However, excessive overshooting of the actual boost pressure exceeding the target booth pressure may cause a situation in which the original performance of the turbocharger cannot be fully exhibited, for example, deterioration of exhaust gas performance.
The turbocharger drive control method in the embodiment of the present invention is made from the viewpoint of avoiding the disadvantages in the conventional vehicle as described above.

Hereinafter, a specific procedure of the turbocharger drive control process suitable for the automatic vehicle in the embodiment of the present invention will be described with reference to FIGS. 4 and 5.
When the processing by the electronic control unit 7 is started, first, the boost pressure control state is confirmed (see step S202 in FIG. 3). That is, it is determined whether boost pressure control by PID control is performed, in other words, whether feedback control described in step S104 shown in FIG. 2 is performed.

  If it is determined in step S202 that boost pressure control by PID control is being performed (in the case of YES), the process proceeds to step S204 described below, while boost pressure control by PID control is performed. If it is determined that the boost pressure has not been reached (in the case of NO), the boost pressure is in a state of being controlled by feedforward control (see step S106 in FIG. 2). Assuming that there is not, the process returns to the main routine (not shown).

  In step S204, it is determined whether or not the speed change gear (not shown) of the automatic transmission 8 is in a position other than neutral (N) or parking (P), and the gear position is set to neutral (N ) Or when it is determined that the position is other than parking (P) (in the case of YES), the process proceeds to step S206 described below. On the other hand, when the electronic control unit 7 determines in step S204 that the gear position is not a position other than neutral (N) or parking (P) (in the case of NO), the gear position is neutral. Since it is not in a state in which a series of subsequent processes are executed assuming that it is in the position of (N) or parking (P), the process once returns to the main routine (not shown).

  Next, in step S206, it is determined whether or not a gear shift down has occurred in the automatic transmission 8, and if it is determined that a gear shift down has occurred (in the case of YES), the following step S208 is performed. On the other hand, if it is determined that the gear shift down has not occurred (NO), the process returns to the main routine (not shown) because it is not in a state where a series of subsequent processes are executed.

  Next, in step S208, it is determined whether or not the torque or fuel injection amount exceeds a predetermined threshold value of the predetermined torque or fuel injection amount, and the torque or fuel injection amount exceeds the predetermined threshold value. If it is determined (if YES), the process proceeds to step S210 described below, while if it is determined that the torque or fuel injection amount does not exceed the predetermined threshold value (NO), Since there is no state in which a series of subsequent processes are executed, the process temporarily returns to a main routine (not shown).

In step S208, it is determined whether or not the torque or the fuel injection amount exceeds a predetermined threshold value because of the problem in the conventional automatic vehicle as described above, that is, uphill traveling, and the gear shift down is performed. One of the conditions that cause the problem that the boost pressure excessively exceeds the target boost pressure and causes the exhaust gas performance to deteriorate is that the torque or the fuel injection amount exceeds a predetermined threshold. Because.
Note that the predetermined threshold value for torque and the predetermined threshold value for fuel injection amount are different depending on the specific conditions of the vehicle, and are preferably determined based on simulations and tests.

In step S208, whether to determine the torque or the fuel injection amount is arbitrarily determined, and any may be determined.
Further, since the torque and the fuel injection amount are calculated and calculated in the fuel injection control process performed by the electronic control unit 7, it is not necessary to calculate and calculate specially for the processes of FIG. 4 and FIG. It is preferable to use the value calculated and calculated in the fuel injection control process.

  Next, in step S210, it is determined whether or not the vehicle speed exceeds a predetermined threshold. If it is determined that the vehicle speed exceeds the predetermined threshold (in the case of YES), the process of step S212 described below is performed. On the other hand, if it is determined that the vehicle speed does not exceed the predetermined threshold value (in the case of NO), it is not in a state in which a series of subsequent processes are executed, and thus the process returns to the main routine (not shown). .

Here, the vehicle speed is determined because of the problem with the conventional automatic vehicle as described above, that is, when the gear is downshifted while driving uphill, the boost pressure excessively exceeds the target boost pressure. This is because one of the conditions that cause a problem that causes deterioration in exhaust gas performance is that the vehicle speed exceeds a predetermined threshold.
The predetermined threshold value for determining the vehicle speed varies depending on specific conditions of the vehicle, and is preferably determined based on simulations, tests, and the like.

In step S212, time measurement (counting) of a predetermined execution time that is predetermined as a time for executing the PID control calculation stop process and the feedforward subtraction value process described after step S214 is started.
The measured time is substituted into the time count value T1 as a variable.
Along with the start of time measurement in the electronic control unit 7, the processes of steps S214 to S218 and the processes of steps S220 to 226 are executed in parallel.

In the embodiment of the present invention, for the sake of convenience of explanation, the processing in steps S214 to S218 is referred to as “PID control calculation stop processing”, and the processing in steps S220 to S226 is referred to as “feedforward subtraction value processing”.
First, the PID control calculation stop process will be described. In the process of step S214, the calculation process in the PID control for boost pressure control is stopped.

That is, when step S214 is executed, it is assumed that boost pressure control is performed by feedback control by PID control as described above. However, in step S214, P in the PID control is assumed. While the (proportional) component and the D (differential) component are forcibly set to zero, the I (integral) component is maintained (fixed) at the latest value.
FIG. 6 schematically shows the change in the calculated value of the PID control together with the change in the feedforward control value, which will be described later, and the following describes how the PID components shown in FIG. .

In FIG. 6, the horizontal axis represents time, and the vertical axis represents changes in each control value.
In the figure, the characteristic line denoted by reference numeral g2-6 indicates the change in the P component in PID control, the characteristic line indicated by reference numeral g3-6 indicates the change in the D component in PID control, and the characteristic line indicated by g4-6. The attached characteristic lines schematically represent changes in the I component in PID control.
In the figure, time t1 is the time point when the calculation of PID control is stopped by the process of step S214, and the P component and D component are from this point until the time count value T1 reaches the predetermined stop time Ts. , Both are maintained at zero, and the state in which the I component is maintained at the latest value is represented by symbols g2-6, g3-6, and g4-6.
In FIG. 6, a characteristic line denoted by reference numeral g5-6 represents a change in the target boost pressure. At time t1, a gear shift is performed, and the torque (or fuel injection amount) and the vehicle speed are increased. A state in which the target boost pressure is increased by being above the respective predetermined thresholds is shown.

Here, returning to the description of FIG. 5 again, after the PID control calculation is stopped as described above, in step S216, it is determined whether or not the actual boost is equal to or higher than the pressure target boost pressure. It becomes. In FIG. 5, for the sake of convenience, the target boost pressure is indicated as “target pressure”, and the actual boost pressure is indicated as “actual pressure”.
In step S216, when it is determined that the actual boost pressure is equal to or higher than the target boost pressure (in the case of YES), a series of processes are terminated as the subsequent process is not executed, and the main process (not shown) is performed. Return to the routine.
As described above, when it is determined that the actual boost pressure is equal to or higher than the target boost pressure, the PID control calculation stop process is terminated and the PID control calculation is started when the actual boost pressure exceeds the target boost pressure. This is because, in PID control, the control value becomes a negative value, thereby suppressing an increase in boost pressure, and an effect of suppressing an excessive increase in boost pressure can be expected.

  On the other hand, when it is determined in step S216 that the actual boost pressure is not equal to or higher than the target boost pressure (in the case of NO), the actual boost pressure is set to the target boost pressure as an effect obtained by executing the process in step S214. If the time count value T1 has reached the predetermined stop time Ts, it is determined whether or not the time count value T1 has reached the predetermined stop time Ts, and it is determined that the time count value T1 has not yet reached the predetermined stop time Ts. In the case of (NO), the process returns to the previous step S214, and a series of processes are repeated.

  On the other hand, when it is determined in step S218 that the time count value T1 has reached the predetermined stop time Ts (in the case of YES), a series of processing is ended, assuming that there is no need for the PID control calculation stop processing, Return to the main routine that is not performed. As a result, the PID control in the boost pressure control returns to the normal control state.

Next, feedforward subtraction value processing in steps S220 to S226 will be described.
First, in step S220, the subtraction value for the feedforward control is calculated by a predetermined arithmetic expression by the electronic control unit 7, and is output for the feedforward control.
As described above in the precondition, when the series of processes shown in FIGS. 4 and 5 are performed, the boost pressure control is performed by performing feedback control by PID control and feedforward control in parallel. It has become what.

In step S220, a subtraction value for subtracting the control value in the feedforward control described above is calculated by a predetermined arithmetic expression, and the calculated subtraction value is added to the feedforward control, that is, control in the feedforward control. The value is subtracted by the subtraction value.
Here, the predetermined arithmetic expression for calculating the subtraction value can calculate an appropriate subtraction value according to the values of these parameters, for example, using the engine speed, the fuel injection amount, the engine cooling water temperature, and the atmospheric pressure as parameters. As described above, it is preferable to use one derived based on a simulation, a test, or the like.

Note that the engine cooling water temperature and the atmospheric pressure are used in the predetermined arithmetic expression for calculating the subtraction value as described above because, for example, when the engine cooling water temperature is in a low water temperature state, the air density becomes high. If the subtraction value is the same as that at room temperature (approximately 20 ° C.), excessive supercharging will occur, so that the subtraction value is made larger than normal temperature to prevent this.
In addition, since the air density is high at low pressure, there is a possibility of supercharging if the subtraction value is the same as the assumed atmospheric pressure at an altitude of 0 m, so the subtracted value is made smaller than the assumed atmospheric pressure at an altitude of 0 m. This is because an appropriate subtraction value according to the environment can be set.

  After the feed forward control subtraction value is output as described above, the subtraction value is gradually returned to zero by the ramp process (see step S222 in FIG. 5). That is, the subtraction value is gradually reduced toward zero over time during a predetermined time. Here, for the predetermined time, an appropriate value should be set so as not to cause a sudden change in the subtraction value from the viewpoint of ensuring the stability of the control, etc. Since it varies depending on the specific conditions of each vehicle, it is preferable to determine based on simulations and test results.

Here, how the feedforward control value is changed and how the subtracted value is changed by the processing of steps S220 and S222 shown schematically in FIG. 6 will be described.
That is, the characteristic line denoted by reference numeral g1-6 in FIG. 6 schematically represents the state of change in the feedforward control value. At time t1, as the process of step S220 is executed, the feed line is fed. At the same time as the forward control value becomes smaller by the above-mentioned subtraction value, the feedforward control value gradually returns to the value before the subtraction due to the decrease of the subtraction value with the passage of time as the process of step S222 is executed. It has become a thing.

  After step S222 is executed as described above, it is determined whether or not the subtraction value has reached zero (see step S224 in FIG. 5), and it has been determined that the subtraction value has not yet reached zero. In the case (in the case of NO), the control by the electronic control unit 7 returns to the previous step S222 and the ramp process is continued, while the subtraction value is determined to have reached zero (in the case of YES). The control by the electronic control unit 7 proceeds to the process of step S226 described below.

In step S226, it is determined whether or not the time count value T1 has reached the predetermined stop time Ts, and when it is determined that the time count value T1 has not yet reached the predetermined stop time Ts (in the case of NO). Then, the process returns to the previous step S222, and a series of subsequent processes are repeated.
On the other hand, if it is determined in step S226 that the time count value T1 has reached the predetermined stop time Ts (in the case of YES), a series of processing is terminated and not shown in the drawing, assuming that there is no need for feedforward subtraction value processing. Return to the main routine.
In FIG. 6, the time reduction of the predetermined stop time Ts is schematically shown by a characteristic line denoted by reference numeral g7-6.

  By performing the PID control calculation stop process and the feedforward subtraction value process as described above, the actual boost pressure is different from the conventional characteristic line shown in FIG. Even if the target boost pressure increases, the target boost pressure is reached without exceeding the target boost pressure.

FIG. 6 shows an example in which the actual boost pressure reaches the target boost pressure after the lapse of the predetermined stop time Ts. However, the actual boost pressure reaches the target boost pressure before the lapse of the predetermined stop time Ts. FIG. 7 schematically shows changes in control values and the like corresponding to FIG. 6 in that case, and this figure will be described below.
First, the correspondence relationship between each characteristic line in FIG. 7 and each characteristic line in FIG. 6 is that the characteristic line denoted by reference numeral g1-7 is attached to the characteristic line denoted by reference numeral g1-6. The characteristic line indicated by g2-6 is added to the characteristic line indicated by g3-6, and the characteristic line indicated by g3-7 is assigned by g4-7 to the characteristic line indicated by g3-6. The characteristic line is denoted by the reference character g4-6, the characteristic line denoted by the reference g5-7 is the characteristic line denoted by the reference g5-6, and the characteristic line indicated by the reference g6-7. , The characteristic line labeled g6-6 corresponds to the characteristic line labeled g7-6, and the characteristic line labeled g7-6 corresponds to the characteristic line labeled g7-6.

In this example, the actual boost pressure has reached the target boost pressure at time t2 before the predetermined stop time Ts has elapsed, and some overshoot and undershoot have occurred after reaching the target boost pressure (FIG. 7) (refer to the characteristic line denoted by reference numeral 5-7 and the characteristic line denoted by reference numeral 6-7), unlike the conventional case, the exhaust gas performance is deteriorated and the performance of the turbocharger is reduced. Absent.
The characteristic line labeled with g7-6 in FIG. 7 schematically shows how the time measurement is reset to zero at time t2.

  Then, PID control is started as the actual boost pressure reaches the target boost pressure, and the P component and I component in PID control are temporarily negative in response to the overshoot from the target boost pressure of the actual booth pressure. (Refer to the characteristic line labeled with g2-7 in FIG. 7).

DESCRIPTION OF SYMBOLS 1 ... Turbocharger 2 ... Turbo actuator 3 ... Engine 5 ... Electromagnetic vacuum adjustment valve 7 ... Electronic control unit 8 ... Automatic transmission 11 ... Atmospheric pressure sensor 12 ... Rotation sensor 13 ... Vehicle speed sensor 14 ... Water temperature sensor 15 ... Intake pressure sensor

Claims (6)

A turbocharger drive control method in a turbocharger drive control device that is mounted on a vehicle having an automatic transmission and configured to be capable of varying a supercharging pressure,
When the shift gear of the automatic transmission is gear-shifted down at a position other than neutral and parking, the torque or fuel injection amount exceeds a predetermined torque value or a predetermined fuel injection amount, and the vehicle speed reaches a predetermined vehicle speed. If you are over
During the predetermined stop time
While stopping the PID calculation of the PID control in the feedback control by the PID control of the supercharging pressure,
A turbocharger drive control method characterized by subtracting a predetermined value from a control value in the feedforward control of the supercharging pressure and gradually decreasing the subtracted value to zero.   3. When stopping the PID calculation, the values of the P component and the D component are forcibly set to zero, while the value of the I component is maintained at a value immediately before the PID calculation is stopped. The turbocharger drive control method described.   The turbocharger drive control method according to claim 2, wherein if the actual boost pressure exceeds the target boost pressure before the predetermined stop time is reached, the stop of the PID calculation is terminated. It is mounted on a vehicle having an automatic transmission, and has a turbocharger and an electronic control unit that controls the operation of the turbocharger, and is configured to be able to control the supercharging pressure by the operation control of the turbocharger. A turbocharger drive control device comprising:
The electronic control unit is
It is determined that the gear for shifting of the automatic transmission has been gear-shifted down at a position other than neutral and parking, the torque or fuel injection amount exceeds a predetermined torque value or a predetermined fuel injection amount, and the vehicle speed reaches a predetermined vehicle speed. When it ’s determined that it ’s exceeded,
During a predetermined stop time, while stopping the PID calculation of the PID control in the feedback control by the PID control of the supercharging pressure,
A turbocharger drive control device configured to subtract a predetermined value from a control value in the feedforward control of the supercharging pressure and gradually reduce the subtracted value to zero.   The electronic control unit is configured to forcibly set the values of the P component and the D component to zero when the PID calculation is stopped, while maintaining the value of the I component at a value immediately before the PID calculation is stopped. The turbocharger drive control apparatus according to claim 4, wherein   The electronic control unit is configured to end the stop of the PID calculation when it is determined that the actual boost pressure exceeds the target boost pressure before the predetermined stop time is reached. The turbocharger drive control device described.

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