KR101511960B1 - Motor driving apparatus and method for fuel pump - Google Patents

Abstract

The present invention relates to a motor driving apparatus and a method for a fuel pump, comprising: a pressure detection unit detecting the pressure of a fuel pumped from the fuel pump by driving a fuel pump motor supplied to a high pressure pump through a fuel supply line; a control unit generating a control signal to control an operation of a motor by making a motor output be close to target fuel pressure based on the target fuel pressure received from a main control unit of a vehicle and a detection signal of the pressure detection unit to be stabilized; and a motor driving unit driving the motor based on a control signal of the control unit. By controlling a motor output in accordance with the target fuel pressure and real fuel pressure, frequent increase and decrease in pressure is prevented to stabilize fuel pressure.

Description

TECHNICAL FIELD [0001] The present invention relates to a motor driving apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump motor driving device and a driving method thereof, and more particularly to a fuel pump motor driving device and a driving method for controlling driving of a fuel pump motor for supplying fuel to an engine will be.

Generally, fuels stored in fuel tanks in gasoline, diesel, gas fueled vehicles, hybrid cars or plug-in hybrid vehicles are supplied to the engine using fuel pumps.

At this time, the amount of fuel supplied to the engine is controlled by controlling the rotation speed of the pump in consideration of the speed of the vehicle.

The motor that drives the fuel pump uses a BLDC motor (Brushless DC Motor) to ensure high efficiency, long service life and reliability, and it is common to use a sensorless BLDC motor in particular.

Recently, many researches and developments have been made to improve the fuel efficiency of automobiles.

The applicant of the present invention has proposed a fuel pump motor drive device technology capable of improving the fuel economy of an automobile by precisely controlling the rotational speed of the motor for fuel pump is disclosed in Korean Patent Registration No. 10-0649355 (published on Nov. 27, 2006, Patent Document 1 ").

The fuel pump motor driving apparatus according to Patent Document 1 controls the rotation speed by improving the response of the motor to the set rotation speed by directly switching the power supply voltage of the motor vehicle supplied from the power supply unit to drive the fuel pump motor.

Korean Patent Registration No. 10-0649355 (published on November 27, 2006)

However, the fuel pump motor driving apparatus according to Patent Document 1 receives the duty value of the PWM control signal received from the ECU, receives the duty value, and drives the motor at a predetermined speed according to the input duty value.

That is, the fuel pump motor driving apparatus according to Patent Document 1 controls the driving of the fuel pump motor based on the PWM control signal of the ECU according to the engine RPM of the vehicle, There is a limit to precisely control the fuel pressure of the engine.

Accordingly, the fuel pump motor driving apparatus according to Patent Document 1 increases the power consumption of the motor due to unnecessary driving of the fuel pump motor, increases the amount of fuel that is injected from the engine and is recycled, There is a problem that the fuel consumption is lowered.

On the other hand, in the fuel pump motor driving apparatus according to the related art, as the fuel is supplied by fully driving the motor in order to minimize the target pressure reaching time immediately after the power is applied during the initial driving, overshoot or undershoot is excessive There was a problem to be solved.

The fuel pump motor driving apparatus according to the related art has a problem in that the pressure rise becomes excessive as the motor output is compensated based on the slope of the acceleration state sensing signal in the section where the actual fuel pressure is not lowered.

Further, the fuel pump motor driving apparatus according to the related art sets a minimum applied voltage to be applied to the motor based on a predetermined set pressure in order to prevent an excessive decrease in fuel pressure, .

Also, the fuel pump motor driving apparatus according to the related art has a problem in that the pressure followability is very sensitive due to the gain setting in the proportional integral control process, so that the pressure fluctuation is significant and the pump is susceptible to the disturbance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel pump motor drive apparatus and a drive method for controlling a fuel pump motor by differentiating a motor drive output based on a target fuel pressure.

It is another object of the present invention to provide a fuel pump motor driving apparatus and a driving method capable of preventing an increase in pressure by compensating the motor output by determining whether the actual fuel pressure is lowered.

It is still another object of the present invention to provide a fuel pump motor drive apparatus and a drive method capable of changing a minimum applied voltage based on a target pressure to prevent a pressure drop in all pressure ranges.

It is still another object of the present invention to provide a fuel pump motor drive apparatus and a drive method capable of securing pressure stability by reducing sensitivity in a steady-state section.

In order to achieve the above object, a fuel pump motor driving apparatus according to the present invention is a fuel pump motor driving apparatus which includes a fuel pump motor for driving a fuel pump, A control unit for generating a control signal for controlling driving of the motor so as to approximate the motor output to the target fuel pressure based on the target fuel pressure received from the main control unit of the vehicle and the sensing signal of the pressure sensing unit, And a motor driving unit for driving the motor based on the signal.

In order to achieve the above object, a fuel pump motor driving method according to the present invention is characterized in that an actual pressure deviation is generated based on a target fuel pressure received from a main control part of a vehicle and an actual fuel pressure supplied through a fuel supply amount The control of the fuel pump motor is controlled so as to compensate the fuel pressure only.

As described above, according to the fuel pump motor driving apparatus and the driving method of the present invention, the motor output can be adjusted according to the target fuel pressure and the actual fuel pressure, so that the fuel pressure can be stabilized by preventing frequent rise and fall of pressure Effect is obtained.

That is, according to the present invention, it is possible to determine whether an actual fuel pressure drop has occurred using the fuel amount compensating unit, and to compensate the motor output only when actual fuel pressure drop has occurred, thereby preventing frequent pressure increase.

According to the present invention, it is possible to inhibit excessive fuel pressure compensation by prohibiting re-entry into the fuel amount compensation logic for a set time after the motor output is compensated.

Further, according to the present invention, when the motor is initially driven by the fuel pump, the motor output is differentiated and regulated according to the target fuel pressure by using the initial drive regulating portion, thereby preventing excessive increase or decrease in pressure, Is obtained.

Particularly, according to the present invention, when applied to a fuel supply system of a hybrid vehicle or a plug-in hybrid vehicle, it is possible to prevent the frequent execution of the initial driving logic when frequent mode changes occur between the electric driving mode and the engine driving mode Loses.

Further, according to the present invention, it is possible to minimize the pressure drop by differentiating the minimum applied voltage of the motor output according to the target fuel pressure using the voltage limiting unit.

According to the present invention, when applied to a fuel supply system of a plug-in hybrid vehicle, the stability of the fuel pressure can be improved by minimizing the fluctuation of the fuel pressure in the steady-state section by reducing the sensitivity of the pressure control using the pressure- Effect is obtained.

1 is a block diagram of a gasoline direct injection system to which a fuel pump motor driving apparatus according to a preferred embodiment of the present invention is applied;
FIG. 2 is a graph showing a sensing signal characteristic of the acceleration state sensing unit according to an angle change of the accelerator pedal,
3 is a configuration diagram of a fuel pump motor driving apparatus according to a preferred embodiment of the present invention,
4 is a graph illustrating the fuel amount compensation operation of the fuel amount compensation section according to the actual fuel pressure and the target fuel pressure,
5 is a waveform graph showing the motor output measured by the fuel amount compensating operation of the fuel amount compensating unit,
6 is a waveform graph output according to the motor drive output adjustment operation of the initial drive regulator according to the target fuel pressure,
7 is a waveform graph output according to the minimum applied voltage limiting operation of the voltage limiter according to the target fuel pressure,
8 is a waveform graph output in accordance with the pressure follow-up control operation of the pressure follow-
FIG. 9 is a flowchart illustrating a method of driving a fuel pump motor driving apparatus according to a preferred embodiment of the present invention,
10 is a waveform graph showing the motor output according to the driving method of the fuel pump motor driving apparatus shown in FIG.

Hereinafter, a fuel pump motor driving apparatus and a driving method according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In this embodiment, a fuel pump motor applied to a gasoline direct injection system will be described.

However, the present invention is not necessarily limited to the gasoline direct injection system, but may be applied to a gas fuel supply system for supplying a gaseous fuel in a liquid state to an engine, such as an Elpia system or an Elpidais system, a diesel direct injection system, And plug-in hybrid fueling systems, as will be appreciated by those skilled in the art.

FIG. 1 is a block diagram of a gasoline direct injection system to which a fuel pump motor driving apparatus according to a preferred embodiment of the present invention is applied, and FIG. 2 is a graph of a sensing signal characteristic of an acceleration state sensing unit according to an angle change of an accelerator pedal.

The gasoline direct injection system to which the fuel pump motor driving apparatus according to the preferred embodiment of the present invention is applied includes a fuel pump for pumping the fuel stored in the fuel tank, a fuel pump for supplying the fuel pumped by the fuel pump to the high- Line, a fuel recovery line for returning the remaining fuel injected from the engine to the fuel tank, and a regulator for maintaining the pressure of the fuel recovered through the fuel recovery line at a preset pressure.

1, the gasoline direct injection system includes a main control unit 10 for calculating a target pressure of fuel supplied to the engine based on a running state of the vehicle, a main control unit 10 for communicating with the main control unit 10, The target pressure received from the control unit 10 is compared with the actually sensed actual fuel pressure in the fuel supply line (not shown) and the driving speed of the motor 12 provided in the fuel pump 11 is controlled according to the comparison result A high-pressure pump 13 for pumping fuel supplied by the fuel pump motor drive device 20 and the fuel pump 11 to a preset high pressure and an injector 14 for injecting fuel pressurized at a high pressure into the cylinder of the engine And an acceleration state sensing unit 15 for sensing an acceleration state of the vehicle.

The acceleration state sensing unit 15 is provided as an acceleration pedal sensor that senses the angle of the accelerator pedal when the driver operates the accelerator pedal. The accelerator pedal sensor senses the acceleration state sensing signal that senses the angle of the accelerator pedal To the main control unit (10).

2, the acceleration pedal is operated from an idle state to a patial state, for example, to set a predetermined upper threshold angle, for example, 30 And outputs a " high "

On the other hand, the acceleration state sensing unit 15 outputs a 'low' signal when the accelerator pedal operation is stopped and the idle state is changed from the partial state to the predetermined lower limit angle, for example, less than 20 degrees.

That is, the detection signal of the acceleration state sensing unit 15 outputs an output value according to the hysteresis characteristic.

The configuration of a fuel pump motor driving apparatus according to a preferred embodiment of the present invention applied to such a gasoline direct injection system will be described in detail with reference to FIGS. 3 and 4. FIG.

3 is a configuration diagram of a fuel pump motor driving apparatus according to a preferred embodiment of the present invention.

The fuel pump motor driving apparatus 20 according to the preferred embodiment of the present invention compensates the fuel pressure according to the slope of the acceleration state sensing signal, In order to prevent the fuel pressure from being lowered, the control is performed such that the motor output is compensated only by a preset ratio when the actual fuel pressure is equal to or smaller than a predetermined set pressure difference with respect to the target fuel pressure.

The fuel pump motor driving device 20 is configured to control the fuel pump motor driving device 20 to increase the fuel pressure in accordance with the target fuel pressure in order to prevent excessive increase and decrease in pressure that occurs when the fuel pump motor is fully driven to minimize the target fuel pressure reaching time, The motor drive is controlled to regulate the output of the pump.

The fuel pump motor driving apparatus 20 further includes a fuel pump motor driving device 20 for controlling the fuel pump motor drive device 20 such that the target fuel pressure limits the minimum applied voltage applied to the motor on the basis of the predetermined reference pressure to prevent excessive decrease of the fuel pressure and corrosion of the commutator, In order to prevent the decrease prevention effect from being reduced, the minimum applied voltage to be applied to the motor is varied according to the target fuel pressure so as to minimize the pressure drop.

Further, instead of setting an excessive proportional integration control term for quick response of the pressure control, the fuel pump motor drive device 20 may be configured such that, when the pressure deviation between the target fuel pressure and the actual fuel pressure is less than a predetermined set pressure deviation The proportional control period is set to '0' so that the proportional control is not performed, and the integration control period is increased to control the pressure to follow the integral control when the pressure decreases.

To this end, the fuel pump motor driving apparatus according to the preferred embodiment of the present invention is pumped from the fuel pump 11 by driving of the fuel pump motor 12, as shown in Fig. 3, A pressure sensor 22 for sensing the pressure of the fuel supplied to the pressure sensor 22 and a pressure sensor 22 for detecting the pressure of the fuel supplied to the pressure sensor 22 based on the target fuel pressure received from the main control unit 10 of the vehicle, And a motor driving unit 23 for driving the motor 12 in accordance with the control signal of the control unit 21. [

In addition, the fuel pump motor driving apparatus 20 includes an overvoltage protection unit 24 for stably maintaining the driving power supplied from the battery 16 and blocking overvoltage to protect each device, a main control unit 10 A CAN transceiver 25 as communication means for performing CAN communication between the control unit 21 and a CAN controller 26 for controlling the operation of the CAN transceiver 25. [

The control unit 21 compares the target pressure received from the main control unit 10 with the actual fuel pressure sensed by the pressure sensing unit 22 through the CAN transceiver 25 and outputs the duty value of the PWM control signal And a fuel amount compensating unit 40 for controlling the driving of the motor driving unit 23 by using the PWM control signal of the calculated duty value.

For example, FIG. 4 is a graph illustrating the fuel amount compensation operation of the fuel amount compensation section according to the actual fuel pressure and the target fuel pressure.

4, the actual fuel pressure sensed by the pressure sensing unit 22 is set to a preset value with respect to the target fuel pressure received from the main control unit 10 via the CAN transceiver 25, For example, about 7%, when the pressure difference is equal to or greater than about 20 psi (= 0.2 bar).

At the same time, the fuel amount compensating unit 40 may prohibit re-entry into the fuel amount compensation logic for a predetermined set time, for example, about 0.5 second after the motor output is compensated.

5 is a waveform graph of the motor output measured by the fuel amount compensating operation of the fuel amount compensating unit.

As shown in FIG. 5, the present invention can determine whether an actual fuel pressure drop has occurred using the fuel amount compensating unit, and compensate the motor output only when actual fuel pressure drop has occurred, thereby preventing a frequent increase in pressure.

Further, the present invention prohibits re-entry into the fuel amount compensation logic for a set time after the motor output is compensated, thereby suppressing excessive fuel pressure compensation.

The control unit 21 may further include an initial driving control unit 41 that differentiates and adjusts the motor output according to the target fuel pressure during the initial driving time set in the initial driving of the fuel pump 11.

For example, the initial drive regulator 41 may calculate the target fuel pressure for about 0.2 second set as the initial drive time according to the required motor output voltage value calculated by interpolating between the two target fuel pressure values shown in Table 1 below And adjusts the output of the motor 12.

350 ㎪ 500 ㎪ Required motor output voltage 7.7V 9.2V

This interpolation process can be summarized as Equation (1) below.

[Equation 1]

Motor output (%) = (target fuel pressure + X) / input voltage * 100

Here, X is a conversion constant set according to the experimental result, and may be set to about 420 in the present embodiment.

That is, the initial drive regulator 41 can adjust the output of the motor 12 by differentiating it according to the motor output calculated by substituting the target fuel pressure into Equation (1).

When the target fuel pressure at the time of initial driving of the fuel pump 11 is higher than a preset reference pressure, for example, about 300 kPa, and the input voltage is higher than a preset reference voltage, for example, about 10 V The motor drive output can be adjusted according to the motor output calculated by Equation (1).

On the other hand, if the target fuel pressure is equal to or lower than the reference voltage or the input voltage is equal to or lower than the reference voltage, the initial drive regulator 41 can adjust the motor drive output to a preset output value, for example, about 50%.

6 is a waveform graph output according to the motor drive output adjustment operation of the initial drive regulator according to the target fuel pressure.

As shown in FIG. 6, the present invention can minimize the power consumption by preventing the excessive pressure rise and fall as the motor output is differentiated and adjusted according to the target fuel pressure using the initial drive regulator at the initial drive.

In particular, when the present invention is applied to a fuel supply system of a hybrid vehicle or a plug-in hybrid vehicle, the frequent mode change between the electric drive mode and the engine drive mode can be prevented from frequently performing the initial drive logic.

The control unit 21 may further include a voltage limiting unit 42 that differentially limits the minimum applied voltage of the motor output according to the target fuel pressure so as to prevent a pressure drop after the initial driving of the fuel pump 11.

For example, the voltage limiter 42 differentiates the minimum applied voltage of the motor output so as to maintain the motor output calculated by interpolating between the two target fuel pressure values described in Table 2 below after the initial drive time has elapsed Limit.

350 ㎪ 500 ㎪ Minimum applied voltage 6.97V 8.48V

This interpolation process can be summarized as Equation (2) below.

&Quot; (2) "

Motor output (%) = (target fuel pressure + Y) / input voltage * 100

Here, Y is a conversion constant set according to the experimental result, and may be set to about 347 in the present embodiment.

7 is a waveform graph output according to the minimum applied voltage limiting operation of the voltage limiter according to the target fuel pressure.

As shown in Fig. 7, the present invention can minimize the pressure drop by differentiating the minimum applied voltage of the motor output according to the target fuel pressure using the voltage limiting unit.

Although the present embodiment has been described using the gasoline direct injection system, the control unit includes the fuel amount compensating unit 40 that performs the variable pressure control according to the target fuel pressure, but the present invention is not limited thereto It is not.

In other words, the fuel supply system applied to the plug-in hybrid vehicle is not subjected to the variable pressure control, so that the sensitivity of the pressure control should be decreased to secure the stability of the fuel pressure in the steady state section.

For this, the control unit 21 performs a proportional integral control or an integral control according to a pressure deviation with respect to the target fuel pressure and the actual fuel pressure instead of the fuel amount compensating unit 40 to control the pressure follow- 43).

For example, Table 3 below is a proportional control period (P Term) table, and Table 4 is an integral control period (I Term) table.

That is, when the deviation from the target fuel pressure to the actual fuel pressure is less than a predetermined set pressure deviation, for example, about 50 fs, the pressure follow-up control unit 43 performs proportional control The period is set to '0', and the integral control period is increased to control the target fuel pressure to follow the integral control when the pressure decreases.

Pressure deviation (㎪) 10 20 30 40 50 60 P Term (rise) 0 0 0 0 0 400 P Term (descending) 0 0 0 0 0 100

Pressure deviation (㎪) always I Term 10 I Term 100

On the other hand, when the deviation between the target fuel pressure and the actual fuel pressure is equal to or greater than the set pressure deviation, the pressure follow-up control unit 43 performs the proportional integral control according to the proportional integral control period described in Tables 3 and 4, So as to follow it.

8 is a waveform graph output in accordance with the pressure follow-up control operation of the pressure follow-up control unit in the steady-state section.

As shown in FIG. 8, when the present invention is applied to a fuel supply system of a plug-in hybrid vehicle, the sensitivity of the pressure control is reduced using the pressure follow-up control unit to minimize the fluctuation of the fuel pressure in the steady- Can be improved.

3, the control unit 21 includes a voltage regulator 31 for converting the driving power supplied through the overvoltage protection unit 24 into a voltage level required for driving the control unit 21, A voltage output circuit 33 for outputting the driving power from which the voltage level is converted from the voltage regulator 31 to the pressure sensing unit 22 and a pressure sensing unit 22 (Hereinafter referred to as ADC) for converting the detection signal from the analog signal to the digital signal.

The control unit 21 includes high and low side drivers 35 and 36 for generating a switching signal according to the PWM control signal and transmitting the switching signal to the MOSFET devices FET1 and FET2 provided on the high and low sides of the motor driver 23, A reverse voltage prevention circuit 37 for protecting the motor drive unit 23 by turning on the protection element FET3 of the motor drive unit 23 and driving the protection element FET3 off when a reverse voltage is generated, And a current detector 38 for detecting the current of the supplied driving power.

That is, according to the present invention, the control unit is constituted by one integrated circuit, and the high and low side driving units serving as a voltage regulator, an interface, a current detecting unit, a reverse voltage preventing circuit and a motor controller are provided in the integrated circuit, The size of the control unit can be reduced.

Here, the interface 32 is an SPI bus that performs SPI (Serial Peripheral Interface) communication between the CAN controller 26 and the controller 21.

In addition, the interface may further include a communication line (not shown) for transmitting and receiving signals between the main control unit and the control unit in a PWM communication manner.

Accordingly, the present invention can transmit and receive signals via the CAN communication between the main control unit and the control unit, and can continuously drive the motor using the PWM communication in the event of a CAN communication error.

The current detection unit 38 detects a current when the fuel pump is driven by using a resistor provided on a power supply line that supplies driving power to the motor driving unit 23 through the overvoltage protection unit 24. [

Accordingly, the control unit 21 checks whether the drive power source is overcurrent, and stops the drive of the motor 12 when an overcurrent is generated, thereby preventing the failure of the motor and the motor drive unit due to the overcurrent.

The motor driving unit 23 is a three-phase full bridge type using a field effect transistor (hereinafter, referred to as FET) Lt; / RTI >

For example, a high-side and a low-side of a three-phase full-bridge circuit constituting the motor driver 23 are respectively connected to a P-channel metal-oxide semiconductor FET (FET1) and an N-channel MOSFET device (FET2) can be applied.

The motor driving unit 23 may further include a protection element FET3 for blocking the driving power applied to the motor driving unit 23 according to a control signal of the control unit 21 when a reverse voltage is generated.

Accordingly, according to the present invention, the protection element is normally turned on under the control of the control unit, the protection MOFFET element is turned off when a reverse voltage is generated, and the driving power applied to the motor driving unit is cut off to prevent short- can do.

Next, a driving method of a fuel pump motor driving apparatus according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 9 and 10. FIG.

FIG. 9 is a flowchart illustrating a method of driving a fuel pump motor driving apparatus according to a preferred embodiment of the present invention. FIG. 10 is a flowchart illustrating a method of driving the fuel pump motor driving apparatus shown in FIG. This is a waveform graph.

As shown in FIG. 9, the driving method of the fuel pump motor driving apparatus according to the preferred embodiment of the present invention includes the steps of turning on the ignition key (not shown) (S10).

Then, the control unit 21 starts to drive by receiving driving power, calculates a duty value to drive the motor 12 of the fuel pump 11 at a preset initial driving speed, And outputs a PWM control signal.

In detail, the CAN transceiver 25 communicates with the main control unit 10, receives the target fuel pressure from the main control unit 10, and transmits the target fuel pressure to the interface 32 of the control unit 21 (S12).

The pressure sensing unit 22 is pumped by the fuel pump 11 to sense the pressure of the fuel supplied to the engine through the fuel supply line (S14).

Thereafter, the pressure sensing unit 22 continuously senses the pressure of the fuel supplied to the engine through the fuel supply line, and transmits the sensed pressure to the control unit 21.

Accordingly, the initial drive regulator 41 differentiates the target fuel pressure and the input voltage of the drive power source applied from the battery 16 according to the motor output calculated by substituting the equation (1) (S16).

At this time, when the target fuel pressure is higher than a predetermined reference pressure, for example, about 300 kPa and the input voltage is higher than a preset reference voltage, for example, about 10 V, the initial drive regulator 41 outputs the motor output The motor drive output can be adjusted according to the motor speed.

On the other hand, if the target fuel pressure is equal to or lower than the reference voltage or the input voltage is equal to or lower than the reference voltage, the initial drive regulator 41 can adjust the motor drive output to a preset output value, for example, about 50%.

When the initial driving time set to about 0.2 second elapses, the fuel amount compensating unit 40 compares the pressure difference between the actual fuel pressure and the target fuel pressure with a predetermined set pressure difference (S18).

If the pressure deviation is equal to or greater than the set pressure difference, for example, about 0.2 bar, the fuel amount compensation unit compensates the motor output by a predetermined set output, for example, about 7% (S20).

On the other hand, if the pressure deviation is less than the set pressure difference as a result of the comparison in step S18, the controller 21 proceeds to step S22.

In step S22, the voltage limiting unit 42 differentiates and limits the minimum applied voltage of the motor output according to the target fuel pressure so as to prevent the fuel pressure drop and commutator corrosion after the initial drive of the fuel pump 11.

For example, the voltage limiter 42 may limit the minimum applied voltage by differentiating it according to the motor output calculated by substituting the target fuel pressure into the equation (2) after the initial driving time has elapsed.

On the other hand, when applied to the fuel supply system of the plug-in hybrid vehicle, the pressure follow-up control unit 43 of the control unit 21 performs proportional integral control or integral control according to the target fuel pressure and the pressure deviation with respect to the actual fuel pressure, Control to follow pressure.

For example, when the deviation of the target fuel pressure from the actual fuel pressure is less than a predetermined set pressure deviation, for example, about 50 fs, the pressure follow-up control unit 43 does not perform proportional control as shown in Tables 3 and 4 The proportional control period is set to '0', and the integral control period is increased to control the target fuel pressure to follow the integral control when the pressure decreases.

On the other hand, when the deviation between the target fuel pressure and the actual fuel pressure is equal to or greater than the set pressure deviation, the pressure follow-up control unit 43 performs the proportional integral control according to the proportional integral control period described in Tables 3 and 4, So as to follow it.

According to the initial drive control, the fuel amount compensation, the minimum applied voltage limitation, and the pressure follow-up control operation, the motor output can be stabilized by approximating to the target fuel pressure by preventing excessive pressure rise and drop as shown in FIG.

9, the control unit 21 checks whether or not the ignition key is turned off (S24), and controls to repeat the steps S18 to S24 until the ignition key is turned off.

If the ignition key is turned off, the control unit 21 stops driving the fuel pump motor driving apparatus 20 and terminates as the engine operation is stopped and the driving power is shut off.

Through the above process, the present invention can stabilize the fuel pressure by preventing the frequent rise and fall of the pressure by adjusting the motor output according to the target fuel pressure and the actual fuel pressure.

Although the present invention has been described in detail with reference to the above embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

In the above embodiment, the fuel pump motor applied to the gasoline direct injection system has been described, but the present invention is not limited thereto.

That is, the present invention can be applied not only to a gasoline direct injection system but also to a gas fuel supply system for supplying a gaseous fuel in a liquid state, such as an Elpia system or an Elpidia system, to a diesel direct injection system, a hybrid fuel supply system and a plug- The fuel supply system can be changed to be applied to various fuel supply systems.

The present invention is applied to a fuel pump motor drive apparatus and a drive method for stabilizing the fuel pressure by preventing the frequent rise and fall of pressure by adjusting the motor output according to the target fuel pressure and the actual fuel pressure.

10: main controller 11: fuel pump
12: motor 13: high pressure pump
14: Injector 15: Acceleration state sensing unit
16: Battery
20: fuel pump motor drive device 21:
22: Pressure sensing part 23: Motor driving part
24: Overvoltage protection section 25: CAN transceiver
26: CAN controller 31: voltage regulator
32: Interface 33: Voltage output circuit
34: ADC 35: High side driver
36: Low side driver 37: Reverse voltage prevention circuit
38: current detection unit 40: fuel amount compensation unit
41: initial drive regulator 42: voltage regulator
43: Pressure follow-

Claims (11)

A pressure sensing part for sensing a pressure of fuel pumped from the fuel pump by driving of the fuel pump motor and supplied to the high pressure pump through the fuel supply line,
A control unit for generating a control signal for controlling the driving of the motor so as to approximate the motor output to the target fuel pressure based on the target fuel pressure received from the main control unit of the vehicle and the sensing signal of the pressure sensing unit,
And a motor driving unit for driving the motor based on the control signal of the control unit,
The control unit performs proportional integral control or integral control according to a pressure deviation with respect to the target fuel pressure and the actual fuel pressure when the fuel supply system of the plug-in hybrid vehicle performs variable fuel control, And a pressure follow-up control unit for controlling the fuel pump motor. The method according to claim 1,
An overvoltage protection unit for protecting each device by interrupting an overvoltage generated from a driving power source supplied from a battery of the vehicle;
Further comprising communication means for performing CAN communication between the main control portion of the vehicle and the control portion,
The control unit compares the target pressure received from the main control unit with the actual fuel pressure detected by the pressure sensing unit through the communication unit, calculates the duty value of the PWM control signal according to the comparison result, And a fuel amount compensating section for controlling driving of the motor driving section using a signal,
Wherein the fuel amount compensating unit compensates the motor output by a predetermined set output when the actual fuel pressure sensed by the pressure sensing unit is equal to or greater than a predetermined set pressure difference with respect to the target fuel pressure received from the main control unit Device. 3. The method of claim 2,
The control unit may further include an initial driving control unit for differentiating and adjusting the motor output according to the target fuel pressure during a predetermined initial driving time at the initial driving of the fuel pump,
Wherein the initial drive controller adjusts a motor output according to a required motor output voltage value calculated by substituting a target fuel pressure and an input voltage of the drive power source into Equation (1).
Motor output (%) = (target fuel pressure + X) / input voltage * 100.
Where X is a conversion constant set according to the experimental result. The method of claim 3,
Wherein the control unit further includes a voltage limiting unit that differentiates and limits the minimum applied voltage of the motor output according to the target fuel pressure so as to prevent fuel pressure drop and commutator corrosion after the initial drive of the fuel pump,
Wherein the voltage limiting unit limits the target fuel pressure to a minimum applied voltage to maintain the motor output calculated by substituting the target fuel pressure into the equation (2).
Motor output (%) = (target fuel pressure + Y) / input voltage * 100 (2)
Where Y is a conversion constant set according to the experimental result. The method according to claim 1,
When the deviation of the target fuel pressure from the actual fuel pressure is less than a predetermined set pressure deviation, the pressure-follow-up control unit inputs the proportional control period as '0' so as not to carry out the proportional control, increases the integral control period, Controls to follow the target fuel pressure with integral control,
And controls the proportional integral control to follow the target fuel pressure when the deviation between the target fuel pressure and the actual fuel pressure is equal to or greater than the set pressure deviation. Controls driving of the fuel pump motor to compensate the fuel pressure only when actual pressure deviation occurs based on the target fuel pressure received from the main control unit of the vehicle and the actual fuel pressure supplied through the fuel supply amount,
When applied to a fuel supply system of a plug-in hybrid vehicle in which variable fuel control is performed, a proportional integral control or an integral control is performed according to a pressure deviation with respect to a target fuel pressure and an actual fuel pressure using a pressure follow- The fuel pump driving method comprising the steps of: The method according to claim 6,
(a) differentiating and adjusting the motor output based on the target fuel pressure received from the main control unit of the vehicle for a predetermined initial driving time using the initial driving control unit at the initial driving of the fuel pump, and
(b) compensating the motor output by a predetermined set output when the pressure deviation between the target fuel pressure and the actual fuel pressure is equal to or greater than a predetermined set pressure difference using the fuel amount compensating unit after the initial driving time has elapsed Wherein the fuel pump is driven by a motor. 8. The method of claim 7,
In the step (a), when the target fuel pressure is higher than a preset reference pressure and the input voltage is higher than a preset reference voltage, the motor driving output is adjusted according to the motor output calculated by Equation (1)
Wherein the motor drive output is adjusted to a predetermined set output value when the target fuel pressure is equal to or less than the reference pressure or the input voltage is equal to or lower than the reference voltage.
Motor output (%) = (target fuel pressure + X) / input voltage * 100.
Where X is a conversion constant set according to the experimental result. 8. The method of claim 7,
(c) differentially limiting the minimum applied voltage of the motor output based on the target fuel pressure to prevent fuel pressure drop and commutator corrosion after the initial drive of the fuel pump,
Wherein the step (c) limits the minimum applied voltage by differentiating to maintain the motor output calculated by substituting the target fuel pressure into the equation (2).
Motor output (%) = (target fuel pressure + Y) / input voltage * 100 (2)
Where Y is a conversion constant set according to the experimental result. delete 7. The control system according to claim 6, wherein the target fuel pressure follow-
(d1) comparing a deviation between the target fuel pressure and the actual fuel pressure and a predetermined set pressure deviation,
(d2) If the result of the comparison in the step (d1) is less than the set pressure deviation, the proportional control period is set to '0' so that the proportional control is not performed and the integral control period is increased. So as to follow
(d3) controlling the proportional integral control to follow the target fuel pressure when the deviation between the target fuel pressure and the actual fuel pressure is equal to or greater than the set pressure deviation.

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