KR102161252B1 - Method for controlling active air flap in vehicle - Google Patents

Abstract

A method of controlling an active air flap in a vehicle is disclosed. A correction step of correcting a flap open reference value using a pre-calculated maximum motor torque and a motor driving voltage for driving the motor when the vehicle is running; A determination step of determining a control timing of the flap using the vehicle speed and the flap opening reference value; And a control step of controlling a flap mounted on the vehicle using a PWM signal when it is determined that the vehicle speed is equal to or greater than the flap open reference value through the determining step; including, due to a lack of torque during high-speed driving of the vehicle The flap unopened phenomenon can be prevented.

Description

Method for controlling active air flap in vehicle

The present invention relates to a method of controlling an active air flap of a vehicle, and more particularly, to a method of controlling an active air flap of a vehicle capable of preventing the flap from being opened due to insufficient torque in a vehicle running at high speed.

In general, heat exchange parts such as radiators, intercoolers, evaporators, condensers, etc. for cooling each part, including various heat generating parts such as engines, transmissions, and electric equipment, are intensively installed in the engine room of a vehicle.

In order for various heat exchange parts in the engine room to operate stably, external air must be smoothly introduced into the engine room.

To this end, in recent years, heat exchange parts including radiators and the like are not assembled independently, but are modularized and installed as one cooling module in a front end module including a headlamp and a bumper.

Accordingly, an opening for introducing air from the front during driving is formed in the bumper modularized in the front end module, and this opening is applied as a mesh structure in the form of a net or grill to prevent the introduction of foreign substances. Accordingly, when the vehicle travels, external air is introduced through the opening formed in the mesh structure of the bumper, and the introduced air exchanges heat with a cooling module including a radiator or the like.

However, since the opening structure of the mesh structure is fundamentally impossible to control the amount of air introduced during high-speed driving, there is a problem such as a decrease in fuel efficiency due to an increase in resistance of the air introduced into the engine room.

In order to solve this problem, an active air flap (AAF) for actively controlling an inflow amount of air is installed at a location where external air is introduced.

The conventional Korean Patent Publication No. 2011-0132924 is characterized in that the flap can be opened and closed within the upper limit of the motor torque in consideration of the speed, wind speed, and direction of the vehicle.

However, the conventional No. 2011-0132924 does not take into account the distribution of the motor torque, so precise control is impossible, and there is a problem in that the cost of the system is increased by separately providing a wind direction/wind speed detector that senses wind speed and wind direction.

Accordingly, the present invention was devised in view of the above circumstances, and it is possible to effectively prevent the flap from being opened due to a lack of torque during high-speed driving of the vehicle, and it is not necessary to provide a separate wind direction/wind speed sensor, thereby reducing cost and active An object of the present invention is to provide a vehicle active air flap control method capable of simplifying the configuration of an air flap control device.

In order to achieve the above object, a method for controlling an active air flap of a vehicle according to an exemplary embodiment of the present invention is to correct a flap open reference value using a pre-calculated maximum motor torque and a motor driving voltage for driving the motor when the vehicle is running. Correction step; A determination step of determining a control timing of the flap using the vehicle speed and the flap opening reference value; And a control step of controlling a flap mounted on the vehicle using a PWM signal when it is determined that the vehicle speed is equal to or greater than the flap open reference value through the determining step.

A changing step of changing the flap from an open state to a closed state when starting power is applied to the vehicle; And a calculation step of calculating the maximum torque of the motor using a variation time from a state change start point to a state change completion point of the flap, a position change amount of the motor rotor, and a motor driving voltage amount used to drive the motor. Can include.

The calculating step further includes obtaining a motor rotation speed using the change time and a position change amount of the motor rotor, and calculating the maximum motor torque using the motor rotation speed and the motor driving voltage amount. I can.

In the correction step, a torque correction value is calculated by subtracting a torque reference value from the maximum motor torque, a voltage correction value is calculated by dividing a voltage reference value by the motor driving voltage, and the voltage correction value and a correction coefficient are added to the torque correction value. It may further include the step of calculating the flap opening correction value by multiplying.

In the correction step, when the maximum motor torque is greater than or equal to a threshold value, the flap opening reference value is corrected by adding the flap opening correction value, and when the motor maximum torque is less than the threshold value, the flap opening correction value is subtracted from the flap opening reference value. Can be corrected.

The flap opening correction value may be changed by the motor driving voltage which varies according to the operating speed of the flap.

In the determining step, when the vehicle speed is less than a preset flap closing reference value, it is determined as a closing time of the flap, and the flap closing reference value may be less than the flap opening reference value.

The controlling step may include an estimation step of estimating the position of the flap using a feedback voltage value indicating the position of the rotor of the motor; A stop point determination step of determining a control stop point of the flap using the estimated flap position and the target position of the flap; And a determining step of determining a duty of the PWM signal using the maximum motor torque and the motor driving voltage when the estimated flap position through the stopping point determination step does not reach the target position of the flap. It may contain more.

In the determining step, the duty of the PWM signal is increased or decreased by using a change amount of the feedback voltage value representing the operating speed of the flap, and when the torque of the motor operated by the PWM signal reaches the maximum motor torque, the The duty of the PWM signal can be determined as 100%.

In the step of determining the stopping point, when the estimated position of the flap coincides with the target position of the flap, it may be determined as a timing of stopping control of the flap.

According to the method for controlling an active air flap of a vehicle according to an exemplary embodiment of the present invention, the flap opening reference value is corrected in consideration of motor dispersion, and the flap can be stably opened and closed using the corrected flap opening reference value and the vehicle speed.

In addition, by calculating the maximum motor torque using the motor rotation speed and the amount of the motor driving voltage and utilizing it for control, it is possible to prevent the flap from being opened due to insufficient torque during high-speed driving of the vehicle.

In addition, by controlling the motor using a PWM signal whose duty varies according to a change in the motor driving voltage, the operating speed of the flap can be kept constant.

1 is a flowchart schematically illustrating a method of controlling an active air flap of a vehicle according to an exemplary embodiment of the present invention.
2 is a flowchart schematically illustrating a method of calculating a maximum motor torque used for controlling an active air flap of a vehicle according to an exemplary embodiment of the present invention.
3 is a block diagram schematically illustrating an apparatus for controlling an active air flap of a vehicle according to an exemplary embodiment of the present invention.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the implementation of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing a preferred embodiment of the present invention with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and is not limited to the described embodiments. In addition, in order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals in the drawings indicate the same members.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components unless specifically stated to the contrary. In addition, terms such as “... unit”, “... unit”, “module”, and “block” described in the specification mean units that process at least one function or operation, which is hardware, software, or hardware. And software.

Referring to FIG. 1, in the method of controlling an active air flap of a vehicle according to an embodiment of the present invention, a step of driving a vehicle (S101), a step of calculating a pre-calculated maximum motor torque and a motor driving voltage to correct a flap opening reference value. (S103), determining the flap opening time by comparing the vehicle speed and the flap opening reference value (S105), estimating the position of the flap by acquiring a feedback voltage value (S107), the estimated flap position and flap Comparing the target position of the flap to determine whether to stop control (S109), determining the duty of the PWM signal using the maximum motor torque and the motor driving voltage (S111), and using a PWM signal according to the determined duty It may include a step (S113) of controlling the flap by operating the motor.

When the starting power of the vehicle is turned on by the driver in the driving step S101 and the accelerator is operated, the vehicle is driven.

Then, in the correcting step (S103), the maximum motor torque and the current motor driving voltage are calculated to correct the flap open reference value. Here, a method of calculating the maximum motor torque will be described in detail later with reference to FIG. 2.

The motor driving voltage refers to the voltage applied to the motor, and the motor rotation speed can be varied according to the size.

The flap opening reference value is a reference value for the opening time of the flap mounted on the vehicle.If the flap opening correction value is generated by calculating the maximum motor torque and the current motor drive voltage, it will be corrected according to the generated flap opening correction value. I can.

The flap opening correction value first calculates a torque correction value by subtracting a preset torque reference value from the previously calculated motor maximum torque, and calculates a voltage correction value by dividing a preset voltage reference value with the current motor drive voltage. It can be calculated by multiplying the value by the voltage correction value and the correction factor. The torque reference value and the voltage reference value are defined as constants, and the correction factor is defined as a tuning parameter.

The flap opening correction value is expressed as a speed, as the flap opening reference value, and can be added or subtracted from the flap opening reference value to correct the flap opening reference value.

The flap opening correction value may be added to the flap opening reference value to correct the flap opening reference value in the case of a vehicle using a device having a maximum motor torque of a threshold value or more.

In the case of a vehicle using a device in which the maximum motor torque is less than a threshold value, the flap opening correction value may be subtracted from the flap opening reference value to correct the flap opening reference value.

In a device in which the maximum motor torque is greater than or equal to the threshold value (reference torque), the flap can be opened even when the vehicle is traveling at high speed, and thus the flap opening reference value can be corrected by adding a flap opening correction value to the flap opening reference value.

In devices with the maximum motor torque below the threshold, the flap may not be opened when the vehicle is traveling at high speed. In order to prevent the flap from being confined, the flap opening reference value is set to open the flap at a lower speed than the flap opening reference value. By subtracting the flap opening correction value, the flap opening reference value can be corrected.

Here, the reason for correcting the flap open reference value is that if a certain flap open reference value is applied without correction, the motor torque may be insufficient depending on the distribution of the motor torque, and the flap may not open before the flap open reference value (vehicle speed). This is to solve the problem of not being able to make the most of the effects of reducing fuel consumption and increasing aerodynamics, which are the basic purposes of the flap, as the possibility exists and the flap closed state is maintained.

Therefore, if the flap opening reference value that is varied by the motor driving voltage and the flap opening correction value is applied, the flap can be opened in advance when the vehicle is traveling at high speed to prevent the flap sticking phenomenon due to the running wind.

Then, in the determining step S105, the speed of the vehicle and the flap opening reference value corrected by the flap opening correction value are compared to determine the opening timing of the flap mounted on the vehicle.

If the vehicle speed is greater than or equal to the flap opening reference value, it is determined as the flap opening time, and the flap may be opened by a PWM controlled motor.

On the other hand, when the vehicle speed is less than the flap closing reference value when the flap is fully opened, it is determined as the flap closing time, and the flap may be closed by a PWM controlled motor. Here, the flap closing reference value is preferably set smaller than the flap opening reference value in consideration of hysteresis.

Then, in the estimating step S107, the position of the flap is estimated by obtaining a feedback voltage value for controlling the motor that operates the flap. Here, the feedback voltage value may be obtained by a position sensor mounted on the motor.

The position of the flap may be estimated through a feedback voltage value having a value of, for example, 0 [V] to 5 [V] according to the position of the rotor of the motor. For example, if the feedback voltage value is 1 [V], the position of the flap may be estimated as the open position, and if the feedback voltage value is 4 [V], the position of the flap may be estimated as the closed state position.

Then, it is determined whether or not control of the flap is stopped by comparing the position of the flap estimated in step S109 of determining whether to stop the control and the target position of the flap. Here, the target position of the flap refers to a position when the flap is in an open or closed state, and may be defined as a voltage value.

When the estimated position of the flap coincides with the target position of the flap, it may be determined as a timing of stopping control of the flap. Here, the target position of the flap may have a margin to prevent unnecessary driving of the motor due to the occurrence of errors due to external force, inertia of the motor, digital conversion, etc. at the estimated flap position.

Then, when the position of the flap estimated in the determining step S111 does not reach the target position of the flap, the duty of the PWM signal is determined using the maximum motor torque and the current motor driving voltage. Here, the duty of the PWM signal may be increased or decreased according to the amount of change in the feedback voltage value so that the operating speed of the flap is kept constant.

Since the variation of the feedback voltage value corresponds to the operating speed of the flap, it can be used to increase or decrease the PWM signal duty.

In addition, when the torque of the motor according to the amount of change in the current feedback voltage value and the voltage amount of the motor driving voltage reaches the maximum motor torque, the duty of the PWM signal may be determined as 100%.

Then, by operating the motor using the PWM signal according to the duty determined in the controlling step (S113), it is possible to control the flap connected to the motor.

Here, in the closed state, the flap may be opened at a constant speed by the PWM-controlled motor, and in the open state, the flap may be closed at a constant speed by the PWM-controlled motor.

Referring to FIG. 2, the method of calculating the maximum motor torque used for controlling the active air flap of the vehicle includes turning on the vehicle starting (S201), changing the flap from an open state to a closed state (S203), and A step of acquiring a variation time according to a state change of the motor, a position change amount of the motor rotor, and a motor driving voltage amount (S205), a step of calculating a motor rotation speed using the obtained variation time and a position change amount of the motor rotor (S207) ) And calculating the maximum motor torque by using the motor rotation speed and the amount of the motor driving voltage (S209).

In the turning-on step (S201), the vehicle is turned on in order to calculate the maximum motor torque used in the air flap control system of the vehicle. Here, turning on the vehicle is not for actual driving, but a preliminary step for calculating the maximum motor torque.

Then, in the changing step (S203), the flap in the state in which the starting power is applied to the vehicle is changed from the open state to the closed state. Changing the flap from the open state to the closed state is to calculate the motor maximum torque that drives the flap in a state that is not affected by the external environment.

Then, in the acquiring step S205, a variation time according to a state change of the flap, a position variation amount of the motor rotor, and a motor driving voltage amount are acquired. Here, the variable time refers to a time from the point when the flap is opened to the point when the flap is closed, and can be obtained through an arbitrary timer installed in the active air flap control device of the vehicle.

The amount of change in the position of the motor rotor can be obtained through a sensor unit (position sensor) mounted on the motor, and the amount of motor driving voltage can be obtained through a power supply unit supplying a battery voltage.

Then, in the calculating step S207, the change time and the amount of change in the position of the motor rotor are calculated to calculate the motor rotation speed.

Finally, in step S209 of calculating the maximum motor torque, the maximum motor torque is calculated using the motor rotation speed and the amount of motor driving voltage. Here, the maximum motor torque may be calculated through an operation or may be obtained through a motor torque table that records motor torque according to a relationship between a voltage amount and a rotation speed.

3, the active air flap control device 10 of a vehicle according to an embodiment of the present invention includes a power supply unit 100, a communication unit 200, a control unit 300, a motor driving unit 400, a motor 500, and It may include a sensor unit 600.

The power supply unit 100 is a device that supplies a motor driving voltage to a motor, and may supply a voltage of 5 [V] to an active air flap control device of a vehicle or detect an on or off state of an ignition switch of a vehicle. In addition, the power supply unit 100 may measure a motor driving voltage applied to the motor.

The communication unit 200 is a device that transmits various types of vehicle information, and may receive vehicle information such as vehicle speed and coolant temperature from various devices mounted on the vehicle and transmit them to the control unit 300.

The control unit 300 is a device that controls various devices used to control an active air flap of a vehicle, and includes a calculation unit 310, a correction unit 320, a determination unit 330, a position estimation unit 340, and a duty determination unit. 350 may be included.

The calculation unit 310 is a device that calculates the maximum torque of a motor that operates the active air flap of the vehicle.

The calculation unit 310 calculates the maximum motor torque through the variation time during the change of the flap 20 from the open state to the closed state when the vehicle is started, the voltage amount of the motor driving voltage, and the amount of change in the rotor position of the motor. Can be calculated.

The correction unit 320 is a device that corrects a flap opening criterion used to determine the opening timing of the active air flap of the vehicle.

The correction unit 320 may calculate a flap opening correction value using the maximum motor torque calculated by the calculation unit 310 and the current motor driving voltage measured by the power supply unit 100.

The correction unit 320 may correct the flap opening reference value by adding or subtracting the flap opening correction value to the flap opening reference value according to a threshold value (torque) of a motor used in the active air flap control device of the vehicle.

The determination unit 330 is a device that determines when the flap is opened or closed, or when the control operation of the flap is stopped.

The determination unit 330 may not only determine the opening timing of the flap in the closed state according to the vehicle speed and the flap opening reference value, but also determine the closing timing of the flap in the open state according to the vehicle speed and the flap closing reference value.

The determination unit 330 may compare the estimated position of the flap with the target position (open or closed) of the flap and determine a timing to stop flap control (open or close) according to whether or not they match.

The position estimating unit 340 is a device for estimating the current position of the flap, and may estimate the position of the flap through the position of the motor rotor obtained by the sensor unit 600 mounted on the motor. The estimated position of the flap may be used to determine when to stop flap control as described above.

The duty determiner 350 is a device that generates a PWM signal, and may determine the duty of the PWM signal so that the flap operates at a constant speed using the maximum motor torque and the current motor driving voltage.

The duty determiner 350 may determine an increase or decrease in the PWM signal duty according to a change amount of a feedback voltage value corresponding to an operation speed of the flap.

The motor driver 400 is a device that rotates the motor 500 according to a PWM signal whose duty is determined by the duty determination unit 350.

The motor driver 400 may transmit a motor driving voltage to the motor 500 through the control of the PWM signal, and thereby rotate the motor 500.

The motor 500 is a device connected to the flap 20 to open or close the flap through its own rotation.

The sensor unit 600 is a device that is mounted on the motor 500 to measure the rotor position of the motor, and may output the measured rotor position of the motor as a feedback voltage value.

The feedback voltage value may be transmitted to the position estimating unit 340 and used to estimate the position of the flap.

The method according to an embodiment of the present invention can be implemented as a computer-readable code on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. Examples of the recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like, and also include those implemented in the form of a carrier wave (for example, transmission through the Internet). In addition, the computer-readable recording medium can be distributed over a computer system connected through a network to store and execute computer-readable codes in a distributed manner.

The present invention has been described with reference to the embodiments shown in the drawings, but these are only exemplary, and those of ordinary skill in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached registration claims.

100: power supply
200: communication department
300: control unit
310: calculation unit
320: correction unit
330: judgment unit
340: position estimation unit
350: duty determination unit
400: motor drive unit
500: motor
600: sensor unit

Claims (10)

A correction step of correcting a flap opening reference value using a pre-calculated maximum motor torque and a motor driving voltage for driving the motor when the vehicle is running;
A determination step of determining a control timing of the flap using the vehicle speed and the flap opening reference value; And
A control step of controlling a flap mounted on the vehicle using a PWM signal when it is determined that the vehicle speed is equal to or greater than the flap open reference value through the determining step;
Active air flap control method of a vehicle comprising a. The method of claim 1,
A changing step of changing the flap from an open state to a closed state when starting power is applied to the vehicle; And
A calculation step of calculating the maximum motor torque using a variation time from a state change start point of the flap to a state change completion point, a position change amount of the motor rotor, and a motor drive voltage amount used to drive the motor;
Active air flap control method of a vehicle, characterized in that it further comprises. The method of claim 2,
The calculation step is
Further comprising the step of obtaining a motor rotational speed using the change time and the amount of change in the position of the motor rotor,
The active air flap control method of a vehicle, wherein the maximum motor torque is calculated using the motor rotation speed and the motor driving voltage amount. The method according to claim 1 or 2,
The correction step
A torque correction value is calculated by subtracting a torque reference value from the maximum motor torque, a voltage correction value is calculated by dividing the voltage reference value by the motor driving voltage, and flap opening correction is multiplied by the torque correction value by the voltage correction value and a correction factor. Steps to calculate the value
Active air flap control method of a vehicle, characterized in that it further comprises. The method of claim 4,
The correction step
When the motor maximum torque is greater than or equal to the threshold value, the flap opening reference value is corrected by adding the flap opening correction value,
When the motor maximum torque is less than the threshold value, the flap opening reference value is subtracted from the flap opening correction value and corrected. The method of claim 4,
The flap opening correction value is
An active air flap control method for a vehicle, characterized in that it is changed by the motor driving voltage that varies according to the operating speed of the flap. The method of claim 1,
The determining step is
When the speed of the vehicle is less than a preset flap closing reference value, it is determined as a closing time of the flap,
The flap closing reference value is smaller than the flap opening reference value. The method according to claim 1 or 2,
The control step is
An estimating step of estimating the position of the flap using a feedback voltage value indicating the position of the rotor of the motor;
A stop point determination step of determining a control stop point of the flap using the estimated flap position and the target position of the flap; And
A determining step of determining a duty of the PWM signal using the maximum motor torque and the motor driving voltage when the estimated flap position has not reached the target position of the flap through the stopping point determination step;
Active air flap control method of a vehicle, characterized in that it further comprises. The method of claim 8,
The determining step is
The duty of the PWM signal is increased or decreased by using the amount of change in the feedback voltage value representing the operating speed of the flap,
When the torque of the motor operated by the PWM signal reaches the maximum motor torque, the duty of the PWM signal is determined to be 100%. The method of claim 9,
The step of determining when to stop is
When the estimated position of the flap coincides with the target position of the flap, it is determined as a timing of stopping control of the flap.

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