JP2010223201A - Variable nozzle control device for turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable nozzle control device for a turbocharger, capable of maintaining the reproducibility of the control of position to a command value even if the movable range between a full close position and a full open position changes. <P>SOLUTION: This variable nozzle control device of a turbocharger includes an angle sensor for detecting the rotating angle of the rotating shaft of a motor, a storage means for storing the maximum value and the minimum value of the rotating angles of the rotating shaft, an initialization control means for performing an initialization operation by controlling the rotating angle of the rotating shaft of the motor to move the vanes of a movable nozzle to the full open side and the full close side, a movable range determination means which reads the output value of the angle sensor by the initialization control means while the vanes of the movable nozzle are moved between the full open side and the full close side and stores the maximum value and the minimum value of the output values in a storage means, and an opening control means which converts an opening command value for the vanes of the variable nozzle from an engine control device to a target position angle and controls the angle of the vanes so that the output value of the angle sensor is the converted target position angle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a variable nozzle control device for a turbocharger that controls an opening degree of a vane of a variable nozzle of a turbocharger mounted on an automobile with an electronic control actuator in accordance with a control signal from an engine control device.

  Conventionally, as an example of this type of technology, a variable nozzle turbocharger control device for an internal combustion engine disclosed in Patent Document 1 is known. FIG. 4 is a diagram showing a configuration of a variable nozzle turbocharger control device according to the prior art. In FIG. 4, reference numeral 1 denotes a turbocharger, which includes a center housing, a compressor housing, and a turbine housing. The turbocharger 1 is provided with an intake inlet 1a through which air is introduced, and a compressed air supply hole 1b for supplying the air compressed by the turbocharger 1 to the engine 2, and exhaust gas is further supplied from the engine 2. An exhaust gas suction port 1c and a discharge port 1d for discharging the exhaust gas are provided. A variable nozzle (not shown) provided in the turbocharger 1 is disposed between the center housing and the turbine housing.

  Reference numeral 3 denotes a stepping motor. The operation piece 4 is operated by driving the stepping motor 3, and the ring plate provided in the variable nozzle is pressed in the same direction to adjust the size of the gap between the vanes of the variable nozzles. The flow rate of the exhaust gas blown to the turbine wheel is adjusted. Reference numeral 5 denotes an engine ECU (electronic control unit), which receives detection outputs of various sensors provided in the engine, and based on these detection outputs, identifies the operating state of the engine and controls driving of the stepping motor 3. This controls the opening and closing of the vane opening of each nozzle of the variable nozzle, adjusts the flow rate of the exhaust gas blown to the turbine wheel, and also adjusts the amount of air that is forcibly sent for combustion. Is done. A radiator 6 is connected to the engine 2, and cooling water of the engine 2 is circulated through the radiator 6 to be cooled.

  According to this prior art, when an abnormality occurs in the variable nozzle turbocharger control device of the internal combustion engine, during cold start, or at idling, the fully open position of the variable nozzle is set as the initial position of the variable nozzle so that The position of each nozzle vane can be controlled.

  In addition, in a variable nozzle control device for a turbocharger, soot may stick to or stay on the nozzle ring surface in the operating angle range other than the normal operating range of the variable nozzle vane. In accordance with the status indication information from the engine ECU based on the stop of the engine due to the switch being turned off, the vane is operated to the fully open position through the fully closed position at least once in the entire operation area of the vane of the variable nozzle. There are also known variable nozzle control devices capable of performing separation. (For example, refer to Patent Document 2). The operation for performing the separation is called wiping operation. In the wiping operation, when the ignition key is turned off, a wiping command is output from the engine ECU. In response to this, the variable nozzle vane is operated until it hits the fully-closed mechanical stopper, and is then operated until it hits the fully-opened mechanical stopper. When this wiping operation is completed, a power OFF permission signal is output and the power of the variable nozzle control device is turned OFF. By this operation, it is possible to execute the dismissal after the engine is stopped.

JP 2001-107738 A JP 2004-293537 A

  By the way, the variable nozzle control device of a turbocharger shown in Patent Document 2 performs a wiping operation when the power is turned on, and obtains a mechanical stopper position on the fully closed side by abutting against the mechanical stopper on the fully closed side, The movable range is specified by determining the position of the fully open side mechanical stopper by abutting against the fully open side mechanical stopper. The operation for obtaining the fully closed / open position will be described with reference to FIG. The fully opened and fully closed positions at the initial stage of product assembly are the angle sensor values “a” and “b”. In the command output from the engine ECU, the fully open position = 0, the fully closed position = 1000, and a relative range of 0 to 1000. The target position is indicated by the value. At this time, the target position based on the target position command is “X”. When the movable range of the variable nozzle vane is expanded due to wear of the mechanism part to be controlled, the angle sensor values of fully open / closed range from “a” to “a ′” and from “b” to “b ′”. End up. In this state, if the same target position as before wear is indicated, the movable range for the indicated range of the target position is widened, so the target position is “X ′”, and it is related to the control target before wear and after wear. There is a problem that the expected performance at the designated target position cannot be obtained because the positional relationship to be changed is changed.

For example, if the range of values output by the angle sensor that detects the rotation angle of the output shaft of the motor is 0-8192, the fully open position angle sensor value is 5120, and the fully closed position angle sensor value is 3072, the target position command The maximum value of is assumed to be 1000. In this case, the target position command value 1000 is set to the fully closed position, and the target position command value 0 is set to the fully open position. In order to obtain the ratio of the angle sensor value per target position command “1 step”, the value obtained by subtracting the fully closed position angle sensor value from the fully opened position angle sensor value is subtracted from the target position command maximum value. Since we only have to divide by value
(5120-3072) / (1000-0) = 2048/1000 = 2.048
It becomes. At this time, if the target position received by the command output by the engine ECU is set to 700 based on the fully open side, the target position of the output shaft is multiplied by the ratio of the angle sensor value per target position “1step” to the received target position. Then, just add the angle sensor value of the reference position,
700 × 2.048-5120 = 3687
It becomes. That is, the output shaft may be rotated to a position where the angle sensor value is “3687”.

On the other hand, when the mechanism part to be controlled is worn and the movable range is widened, for example, when the fully open position angle sensor value is 5233 and the fully closed position angle sensor value is 2959, similarly, the target position command “1step” When the ratio of the angle sensor value is obtained,
(5233-2959) / (1000-0) = 2274/1000 = 2.274
It becomes. At this time, similarly, when the target position of the output shaft with respect to the command value 700 is obtained,
700 × 2.274-5233 = 3642
It becomes. In other words, the output shaft only needs to be rotated to a position where the angle sensor value is “3642”, and the rotation angle of the output shaft of the motor is different even before and after wear, even if the command value is the same. In addition, there is a problem that the opening degree of the vanes of the variable nozzle is different and the expected performance cannot be obtained.

  The present invention has been made in view of such circumstances, and the position control repeatability with respect to the command value can be improved even if the movable range of the fully-closed / fully-opened position changes due to wear of the mechanism part to be controlled. An object of the present invention is to provide a variable nozzle control device for a turbocharger that can be maintained.

  The present invention controls the vane opening of the variable nozzle by controlling the rotation angle of the rotating shaft of the motor based on a control signal from an engine control device that controls the driving of an engine having a turbocharger having a variable nozzle. A variable nozzle control device for a turbocharger comprising an electronic control actuator for controlling, an angle sensor for detecting a rotation angle of the rotation shaft, and a storage means for storing a maximum value and a minimum value of the rotation angle of the rotation shaft; The initialization control means for controlling the rotation angle of the rotating shaft of the motor and moving the vane of the variable nozzle to the fully open side and the fully closed side to perform the initialization operation, and the initialization control means, While moving the vane of the variable nozzle to the fully open side and the fully closed side, the output value of the angle sensor is read, and the maximum value and the minimum value of the output value are stored in the storage means. Based on the maximum value and the minimum value stored in the storage means, the movable range determination means to remember, the vane opening command value of the variable nozzle from the engine control device is converted into a target position angle, And opening degree control means for controlling the opening degree of the vane so that the output value of the angle sensor becomes the converted target position angle.

  The present invention controls the vane opening of the variable nozzle by controlling the rotation angle of the rotating shaft of the motor based on a control signal from an engine control device that controls the driving of an engine having a turbocharger having a variable nozzle. Variable nozzle control of a turbocharger comprising an electronically controlled actuator comprising an angle sensor for detecting a rotation angle of the rotary shaft and storage means for storing a maximum value and a minimum value of the rotation angle of the rotary shaft for controlling A variable nozzle control program that operates on the apparatus, wherein the rotation angle of the rotation shaft of the motor is controlled, and the vane of the variable nozzle is moved to the fully open side and the fully closed side to perform the initialization operation. While the variable nozzle vane is moved to the fully open side and the fully closed side by the control step and the initialization control step, the output of the angle sensor is Based on the movable range determination step of reading the value and storing the maximum value and the minimum value of the output value in the storage unit, and the maximum value and the minimum value stored in the storage unit, An opening degree control step for converting the opening degree command value of the vane of the variable nozzle into a target position angle and controlling the opening degree of the vane so that the output value of the angle sensor becomes the converted target position angle. It is made to carry out.

  According to the present invention, the target position of the output shaft is calculated based on the movable range information stored during the initialization operation even when the movable range is widened due to wear or the like of the mechanism part to be controlled. The target position control can be performed without being influenced by the above, and the effect that the expected performance of the control target can be reproduced is obtained.

It is a block diagram which shows the structure of one Embodiment of this invention. It is a block diagram which shows the detailed structure of the electronic control actuator 13 shown in FIG. It is a flowchart which shows the processing operation of the movable range determination part 137 shown in FIG. 4 is an explanatory diagram showing a movable range of an output shaft 17. FIG. It is a block diagram which shows the prior art example of the variable nozzle control apparatus of a turbocharger. It is explanatory drawing which shows the movable range of the output shaft by a prior art.

  Hereinafter, a variable nozzle control device for a turbocharger according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing the configuration of the embodiment. In this figure, 8 is a turbocharger, which is a system for supercharging intake air to the engine, which is connected to a compressor having a compressor wheel and a rotor shaft coaxially with the compressor, and is driven to rotate by exhaust gas. A turbine having a turbine wheel of the turbocharger 8 is provided. A pressure sensor 9 is connected to the air passage 7 of the turbocharger 8 via a hose 10 for detecting intake pressure of engine intake air, that is, boost pressure. A variable nozzle member is disposed in the turbine of the turbocharger 8 so as to surround the turbine wheel. The variable nozzle member is provided with a vane that opens and closes in order to control the flow rate of the fluid flowing through the nozzle. The variable nozzle control device controls the opening and closing of the vanes.

  Reference numeral 11 denotes an engine ECU, which is provided with various sensors provided in the engine, for example, a water temperature sensor for detecting the engine water temperature, and for detecting the number of revolutions of the engine. A detection output of a water temperature signal, a rotation signal, and a load signal is introduced from an acceleration sensor that detects an intake air amount by an air flow meter and an accelerator pedal depression amount of a driver and calculates a load amount, respectively. Although not shown in FIG. 1, there may be provided an oxygen sensor that outputs a voltage signal that varies depending on the oxygen concentration of the exhaust gas, and an in-cylinder pressure sensor that detects the pressure in the engine combustion chamber.

  The electronic control actuator 13 is connected to the engine ECU 11 via a control signal line. The engine ECU 11 identifies the operating state of the engine based on the detection output, and drives and controls the electronic control actuator 13 via the control signal line. The electronic control actuator 13 connects the lever 19 and the rod 20, and controls the operation of the vane operation piece 21 connected to each vane in order to control the opening and closing of the vane provided in the turbocharger 8. To do.

  The electronic control actuator 13 is attached to the turbocharger 8, for example. Further, when the configuration of the electronic control actuator 13 is described with reference to FIG. 1 and FIG. 2, the publicly known functions and configurations normally possessed by the electronic control actuator 13 are the same unless directly related to the description of the present invention. Description and illustration of the configuration are omitted.

  Next, a detailed configuration of the electronic control actuator 13 shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a block diagram showing a detailed configuration of the electronic control actuator 13 shown in FIG. In FIG. 2, reference numeral 130 denotes a microcomputer (hereinafter referred to as a microcomputer) that controls the operation of the electronic control actuator 13 in an integrated manner. A motor driver 14 drives a stepping motor (hereinafter referred to as a motor) 15 based on a drive signal output from the microcomputer 130. The motor 15 is a stepping motor whose rotation angle is controlled based on a signal output from the motor driver 14. Reference numeral 16 denotes a gear which is connected to the rotation shaft of the motor 15 and decelerates the rotation shaft of the motor. Reference numeral 17 denotes an output shaft decelerated by the gear 16. Reference numeral 18 denotes an angle sensor that detects and outputs the rotation angle of the output shaft 17. The output of the angle sensor 18 is input to the microcomputer 130.

  Reference numeral 131 denotes an angle signal conversion unit that receives a vane target position (opening) signal output from the engine ECU 11, converts the target position signal into an angle signal handled in the microcomputer 130, and outputs the angle signal. Reference numeral 132 denotes an angle at which a comparison result signal is output by comparing the angle signal of the target position output from the angle signal conversion unit 131 with the angle signal output from the angle sensor 18 (current vane angle (opening)). It is a signal comparison unit. Reference numeral 133 denotes a motor drive duty calculation unit that inputs the comparison result signal output from the angle signal comparison unit 132, and calculates and outputs the duty ratio of the signal to be given to the motor. A motor drive logic generation unit 134 receives a duty ratio signal output from the motor drive duty calculation unit 133 and obtains and outputs a logic signal to be given to the motor. Reference numeral 135 denotes a communication signal conversion unit that converts an angle signal output from the angle sensor 18 into a communication signal for transmission to the engine ECU 11 and outputs the communication signal. The angle information output from the communication signal conversion unit 135 is the actual position information of the current vane.

  Reference numeral 136 denotes an initialization processing unit that receives an initialization command output when the power (ignition key) is turned ON / OFF, and performs initialization processing including wiping operation. An instruction for the initialization operation is issued and the initialization operation is executed. 137 inputs the output value of the angle sensor 18 while the instruction for the initialization operation is issued from the initialization processing unit 136 to the motor drive duty calculation unit 133, and determines the movable range of the output shaft 17. The movable range determination unit outputs movable range information. Reference numeral 138 denotes a movable range storage unit that stores the movable range information output from the movable range determination unit 137.

  Next, the basic operation of the electronic control actuator 13 shown in FIG. 2 will be described with reference to FIG. When the target position signal is output from the engine ECU 11, the angle signal conversion unit 131 converts the target position signal into an angle signal handled in the microcomputer 130 and outputs the angle signal. The angle signal comparison unit 132 compares the angle signal of the target position output from the angle signal conversion unit 131 with the angle signal (current vane angle) output from the angle sensor 18 to determine the current vane angle as a target. To obtain the position, the motor drive duty is calculated and output. In response to this, the motor drive logic generation unit 134 receives the duty signal output from the motor drive duty calculation unit 133 and obtains and outputs a logic signal (motor drive signal) to be given to the motor driver 14.

  The motor driver 14 drives the motor 15 based on the motor drive signal output from the motor drive logic generation unit 134. The rotation shaft of the motor is decelerated by the gear 16 and transmitted to the output shaft 17. The rotational movement of the output shaft 17 is transmitted to the vane operation piece 21 via the lever 19 and the rod 20. As the vane operating piece 21 operates in conjunction with the output shaft 17, the nozzle vane opening / closing control operation is performed. On the other hand, information on the rotation angle of the output shaft 17 detected by the angle sensor 18 is notified to the engine ECU 11 via the communication signal converter 135. The engine ECU 11 controls the operation of the turbocharger 8 with reference to the information on the rotation angle of the output shaft (nozzle vane opening).

  In this way, the rotation angle of the output shaft 17 connected to the vanes of the variable nozzle is detected by the angle sensor 18 and the actual angle signal of the output shaft 17 is output, and the angle signal converter 131 receives the variable nozzle of the variable nozzle from the engine ECU 11. By converting the vane opening degree instruction (target position signal) into a target angle signal of the output shaft 17, comparing both signals, and controlling the rotation angle of the output shaft 17 according to the difference between the two signals, Control is performed so that the vanes of the variable nozzle become the target position.

  Next, the processing operation of the initialization processing unit 136 shown in FIG. 2 will be described with reference to FIG. First, when the ignition key is turned on or off, an initialization command is output to the initialization processing unit 136. In response to this, the initialization processing unit 136 outputs instruction information for performing the vane wiping operation of the variable nozzle to the motor drive duty calculation unit 133. The initialization processing unit 136 controls the rotation angle of the output shaft 17 with respect to the motor drive duty calculation unit 133, and the vane moves in the fully open direction until the vane of the variable nozzle hits the mechanical stopper on the fully open side. To output a duty value. As a result, a predetermined duty value is output from the motor drive duty calculation unit 133, and the motor 15 is driven to move until the vane of the variable nozzle hits the mechanical stopper on the fully closed side.

  The initialization processing unit 136 determines whether or not the vane has hit the mechanical stopper. When the vane hits the fully closed mechanical stopper, the rotation of the motor 15 is reversed to change the vane of the variable nozzle. Is output to the motor drive duty computing unit 133 until it hits the fully open side mechanical stopper. As a result, a predetermined duty value is output from the motor drive duty calculation unit 133, and the motor 15 is driven to move until the vane of the variable nozzle hits the mechanical stopper on the fully open side. The initialization processing unit 136 determines whether or not the vane has hit the mechanical stopper, and ends the initialization process when the vane hits the fully open mechanical stopper. By such an operation, initialization is performed.

  Next, an operation in which the movable range determination unit 137 shown in FIG. 2 acquires and stores the movable range information of the output shaft 17 will be described with reference to FIG. FIG. 3 is a flowchart illustrating an operation in which the movable range determination unit 137 illustrated in FIG. 2 acquires and stores the movable range information of the output shaft 17. The processing operation shown in FIG. 3 is executed in parallel with the above-described initialization operation. First, when the ignition key is turned ON or OFF, the movable range determination unit 137 refers to the execution flag held inside (step S1) and determines whether or not the flag is set (execution flag = 1). Whether or not) (step S2). This execution flag is a flag that is set when the processing operation shown in FIG. 3 is executed. If the execution flag is 1 as a result of this determination, the subsequent processing is not performed. That is, the processing operation shown in FIG. 3 is executed once only when the electronic control actuator 13 is assembled to the turbocharger 8 and is operated for the first time.

  On the other hand, if the execution flag is 0, the movable range determination unit 137 reads information instructing the initialization operation output from the initialization processing unit 136 (step S3), and determines whether or not the initialization operation has been started. Determine (step S4). If the initialization operation is not started as a result of the determination, the process waits until the initialization operation is started. On the other hand, when the initialization operation is started, the movable range determination unit 137 reads the output value of the angle sensor 18 (step S5), and the maximum and minimum output values output from the angle sensor 18 during the initialization process. A value is obtained (step S6). For the maximum and minimum values, if the newly read output value is smaller than the minimum value, this output value is the minimum value. If the read output value is greater than the maximum value, this output value is the maximum value. Repeat this step. Then, the movable range determination unit 137 determines whether or not the initialization process has ended (step S7), and repeats the process until the initialization process ends.

  Next, the movable range determination unit 137 stores the obtained maximum value and minimum value in the movable range storage unit 138 when the initialization process is completed (step S8). Since the movable range storage unit 138 is composed of memory elements that can hold the stored contents without supplying power, the stored maximum and minimum values are stored even when the power is turned off. It does not change. Then, the movable range determination unit 137 sets an execution flag (step S9). With this execution flag set, the processing operation shown in FIG. 3 is not executed even when the ignition key is turned ON / OFF. Therefore, the movable range of the output shaft 17 is specified by the maximum value and the minimum value stored in the movable range storage unit 138. When the angle signal conversion unit 131 receives the target position signals of 0 to 1000 from the engine ECU 11, the movable range minimum value stored in the movable range storage unit 138 is set to “0”, and the movable range maximum value is set to “1000”. assign.

  As described above, even when the movable range is widened due to wear or the like of the mechanism portion to be controlled, the target position of the output shaft is calculated based on the movable range information stored in the movable range storage unit 138. Therefore, the target position control can be performed without receiving, and the expected performance of the control target can be reproduced.

  For example, as shown in FIG. 4, the fully opened / closed positions at the initial stage of product assembly are the angle sensor values “a” and “b”. In the command output from the engine ECU, the fully opened position = 0, the fully closed position = The target position is indicated by a relative value in the range of 0 to 1000, where 1000 is set. At this time, the target position instructed from the command side is “X”. If the movable range of the variable nozzle vane is expanded due to wear or the like, the fully open / closed angle sensor values expand from “a” to “a ′” and from “b” to “b ′”. Since the position of “b” is stored in the movable range storage unit 138 and the fully open / closed angle sensor value stored in the movable range storage unit 138 is used at the time of activation, the control target mechanism It is possible to eliminate the influence of the movable range change due to the wear of the part.

  In the above description, the example in which the initialization command is output when the power supply (ignition key) is turned ON / OFF has been described. However, the initialization command is transmitted from the time when the power of the variable nozzle control device is turned “ON”. It may be output any number of times at any timing until the power is turned off.

  2 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, thereby executing variable nozzle control. Processing may be performed. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  DESCRIPTION OF SYMBOLS 11 ... Engine ECU, 13 ... Electronic control actuator, 130 ... Microcomputer (microcomputer), 131 ... Angle signal conversion part, 132 ... Angle signal comparison part, 133 ... Motor drive Duty Calculation unit 134... Motor drive logic generation unit 135 135 Communication signal conversion unit 136 ... Initialization processing unit 137 ... Movable range determination unit 138 ... Movable range storage unit DESCRIPTION OF SYMBOLS 14 ... Motor driver, 15 ... Motor, 16 ... Gear, 17 ... Output shaft, 18 ... Angle sensor, 19 ... Lever, 20 ... Rod, 21 ... Vane Operation piece

Claims (2)

Electronic control for controlling the opening degree of the vane of the variable nozzle by controlling the rotation angle of the rotating shaft of the motor based on a control signal from an engine control device that controls the driving of the engine equipped with the turbocharger having the variable nozzle. A variable nozzle control device for a turbocharger equipped with an actuator,
An angle sensor for detecting a rotation angle of the rotation shaft;
Storage means for storing the maximum value and the minimum value of the rotation angle of the rotation shaft;
An initialization control means for controlling the rotation angle of the rotation shaft of the motor and moving the vanes of the variable nozzle to the fully open side and the fully closed side to perform an initialization operation;
While the vane of the variable nozzle is moved to the fully open side and the fully closed side by the initialization control unit, the output value of the angle sensor is read and the maximum value and the minimum value of the output value are stored in the storage unit. Movable range determination means;
Based on the maximum value and the minimum value stored in the storage means, the opening command value of the variable nozzle vane from the engine control device is converted into a target position angle, and the output value of the angle sensor is A variable nozzle control device for a turbocharger, comprising: opening degree control means for controlling the opening degree of the vane so as to obtain a converted target position angle. In order to control the opening degree of the vane of the variable nozzle by controlling the rotation angle of the rotating shaft of the motor based on a control signal from an engine control device that controls the driving of an engine equipped with a turbocharger having a variable nozzle. Operating on a variable nozzle control device for a turbocharger comprising an electronic control actuator comprising an angle sensor for detecting a rotation angle of the rotation shaft and a storage means for storing a maximum value and a minimum value of the rotation angle of the rotation shaft A variable nozzle control program for
An initialization control step of controlling the rotation angle of the rotation shaft of the motor and moving the vanes of the variable nozzle to the fully open side and the fully closed side to perform an initialization operation;
The output value of the angle sensor is read while moving the vanes of the variable nozzle to the fully open side and the fully closed side by the initialization control step, and the maximum value and the minimum value of the output value are stored in the storage unit. A movable range determination step;
Based on the maximum value and the minimum value stored in the storage means, the opening command value of the variable nozzle vane from the engine control device is converted into a target position angle, and the output value of the angle sensor is A variable nozzle control program for causing a computer to perform an opening degree control step for controlling the opening degree of the vane so as to obtain a converted target position angle.

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