KR20120062108A - Apparatus and method for fuel pumt motor control - Google Patents

Abstract

PURPOSE: A motor control device for a fuel pump and a control method thereof are provided to exactly control the amount of gas fuel supplied to an engine by preventing the vaporization of liquid gas fuel. CONSTITUTION: A motor control device for a fuel pump comprises a motor driving unit(20), a sensor(100), a valve driving unit(40), a controller, and a power conversion unit(60). The motor driving unit drives a motor(11) for a fuel pump. The sensor senses the driving state of the motor. The valve driving unit drives a fuel cut solenoid valve(12). The controller controls the motor driving unit and the valve driving unit based on driving signals received from an ECU(Electronic Control Unit)(13) of a vehicle. The power conversion unit converts power supplied from a power supply unit into logic power for driving the controller and the motor driving unit, and into driving power for the motor and valve.

Description

Fuel pump motor control device and control method {APPARATUS AND METHOD FOR FUEL PUMT MOTOR CONTROL}

The present invention relates to a fuel pump motor control apparatus and a control method, and more particularly, a fuel cut which is installed in a fuel supply line of a gas fuel vehicle and controls the fuel pump motor and is opened and closed to selectively supply gas fuel. The present invention relates to a fuel pump motor control apparatus and a control method for controlling a solenoid valve.

In general, the gas fuel stored in the fuel tank is supplied to the engine using a fuel pump in a vehicle using gas as fuel.

At this time, the amount of gas supplied to the engine is adjusted by controlling the rotational speed of the pump in consideration of the speed of the vehicle.

The motor that drives the fuel pump uses a brushless DC motor for high efficiency, long life and reliability, and in particular, a sensorless BLDC motor is used.

In recent years, a lot of research and development has been conducted to improve the fuel efficiency of automobiles.

The present applicant discloses a fuel pump motor driving device technology capable of precisely controlling the rotational speed of a fuel pump motor to improve fuel efficiency of a vehicle. Korean Patent Registration No. 10-0649355 (November 27, 2006, Patent Document 1 ') and the like has been registered.

1 is a configuration diagram of a fuel pump motor driving apparatus according to Patent Document 1. FIG.

As shown in FIG. 1, the fuel pump motor driving device 4 according to Patent Document 1 uses a power source supplied from the power supply unit 2 to drive a motor 1 for driving a motor 1 for rotating a fuel pump 5. ) Detects the rotor position (angle) of the motor 1 and the current supplied to the motor 1 through the motor driver 5, and transmits a switching signal for switching the FET device provided in the motor driver 5. The motor controller 7, the gate driver 6 which turns on / off the gate of the FET device according to the switching signal of the motor controller 7, and is transmitted from the ECU 3 of the vehicle through the interface 9. The control unit 8 which outputs a pulse width modulation (PWM) control signal of a duty value set based on a result of comparing the driving speed and the rotation speed data of the motor 1 transmitted from the motor controller 16 to the motor controller 7. ).

The fuel pump motor driving apparatus according to Patent Document 1 having such a configuration can drive the fuel pump motor by directly switching the power supply voltage of the vehicle to precisely control the rotational speed of the motor.

However, there is a limit to the technique of improving the fuel efficiency of an automobile only by precisely controlling the drive of a fuel pump motor like patent document 1.

Therefore, technologies for finding and controlling conditions that may affect fuel economy of automobiles are being researched.

For example, a liquefied petroleum injection (Liquefied Petroleum Injection) type gas fuel vehicle that directly injects liquid gas fuel into the engine is supplied with a gas fuel pumped by a fuel pump. A fuel cut solenoid valve is installed to open and close the fuel supply line.

The ECU generates a drive signal for driving the relay according to the on operation of the ignition key, and the fuel cut solenoid valve lifts the internal plunger using a supply power applied from a battery through a relay driven by the drive signal. To open and close the fuel supply line.

As a result, since the ignition key is always on and operated while the vehicle is driving, the temperature of the fuel cut solenoid valve is increased as the fuel cut solenoid valve is continuously supplied with a supply power from the battery to maintain the driving state. At this time, according to the temperature measurement experiment, the temperature of the fuel cut solenoid valve also rises to 85 ° C.

As such, when the temperature of the fuel cut solenoid valve rises, the temperature of the fuel supply line rises and bubbles of gas are generated while the liquid gas fuel supplied to the engine through the fuel supply line changes to a gaseous state, and the fuel pressure increases. The viscosity of the gas fuel is changed.

Therefore, the conventional fuel pump motor driving apparatus having the fuel cut solenoid valve cannot precisely control the amount of fuel injected from the injector, thereby increasing fuel consumption and lowering fuel economy.

Republic of Korea Patent Registration No. 10-0649355 (announced 27 November 2006)

The present invention is to solve the above problems, an object of the present invention is to control the driving of the motor for the fuel pump and to reduce the voltage applied to the fuel cut solenoid valve to prevent the temperature rise of the fuel cut solenoid valve. It is to provide a fuel pump motor control apparatus and control method that can be.

Another object of the present invention is to provide a fuel pump motor control apparatus and control method capable of precisely controlling the amount of fuel supplied to an engine of a gas fuel vehicle.

According to a feature of the present invention for achieving the above object, the present invention controls the driving of a fuel pump solenoid valve installed in a fuel pump motor and a fuel supply line for supplying fuel pumped by the fuel pump to an engine. A fuel pump motor control apparatus, comprising: motor driving means for driving a motor for a fuel pump, sensing means for sensing a driving state of the motor, valve driving means for driving the fuel cut solenoid valve, and a drive received from an ECU of a vehicle A controller for controlling the driving of the motor driving means and the valve driving means based on a signal and a sensing result of the sensing means, and a logic power source for driving the motor driving means and the control unit and supply power supplied from a power supply of the vehicle. A power conversion unit for converting the driving power required for driving the motor and the valve; The valve driving unit converts the power level of the FET driving signal transmitted from the valve driving unit for driving the valve and the control unit by switching the driving power to a voltage level at which the motor driving unit is driven, and transfers the gate driver to the valve driving unit. Include.

The valve driving unit includes a first FET device, and the gate driver converts the FET driving signal of the logic power supply level into a voltage level of the driving power supply and applies it to the gate of the first FET device.

The present invention further includes a voltage sensing unit for sensing a voltage of the driving power, and the controller is configured to turn the voltage sensed by the voltage sensing unit when the predetermined initial driving time elapses after driving the valve. The PWM duty value of the FET driving signal may be changed and set to maintain the on sustain voltage.

The motor driving means may include a motor driver for driving the motor by switching the driving power, a motor controller for generating a motor driving signal based on a duty value of a PWM control signal applied from the controller, and a voltage level of the motor driving signal. And a second gate driver for converting and applying the voltage to the voltage level of the driving power, wherein the sensing means includes: a rotor position detector for detecting a position of the rotor using a back EMF signal appearing on each phase of the motor when the motor is driven; And an overcurrent detector for detecting an overcurrent applied to the controller and transmitting the overcurrent to the controller.

According to another feature of the present invention, the present invention comprises the steps of: (a) converting a supply power source into a logic power source for driving the motor drive means and a drive power source for driving the fuel pump motor and the fuel cut solenoid valve, (b) Receiving a speed control signal and a valve driving signal for controlling the driving of the motor and the valve from the ECU of the vehicle, (c) controlling the driving of the motor according to the speed control signal received in the step (b) And (d) performing step (c) and controlling driving of the valve based on the valve drive signal, wherein step (d) comprises: (d1) Generating a FET driving signal having a logic power supply level, (d2) converting the FET driving signal generated in the step (d1) to a voltage level of the driving power supply and applying it to a gate terminal of the FET device; (d3) opening the valve based on the FET driving signal applied in the step (d2).

The FET driving signals of steps (d2) and (d3) are set to a PWM duty value of 100%.

The step (d) further includes the step (d4) of maintaining a voltage of the driving power at a turn-on holding voltage of the FET device when a predetermined initial driving time elapses after driving the valve. It features.

In the step (d4), when the voltage level of the driving power detected by the voltage sensing unit is lower than the turn-on holding voltage, the PWM duty value of the FET driving signal is set higher than a preset reference duty, and the detected When the voltage level of the driving power supply is higher than the turn on sustain voltage, the PWM duty value of the FET driving signal may be set lower than the reference duty.

In step (c), (c1) setting the duty value of the PWM control signal according to the target RPM based on the speed control signal, and driving the motor based on the set duty value; Detecting the position of the rotor using the back EMF signal appearing on each phase of the motor, (c3) calculating the current RPM of the motor using the position of the rotor detected in the step (c2), (c4) the And controlling the driving of the motor by changing a duty value of the PWM control signal according to the difference between the current RPM calculated in the step (c3) and the target RPM according to the speed control signal, and (c1) Based on steps to (c4), if the overcurrent is applied to the motor during the driving of the motor, it is characterized in that the driving of the motor is limited.

As described above, in the present invention, when the initial driving time elapses after turning on the fuel cut solenoid valve using the driving power supply, the PWM duty value of the FET driving signal is changed to apply a turn-on holding voltage lower than the driving power supply. To keep the fuel cut solenoid valve open.

Accordingly, the present invention can prevent the temperature rise of the fuel cut solenoid valve by lowering the voltage level of the power supply for driving the fuel cut solenoid valve.

According to the current consumption test, the present invention consumes about 300 mA to maintain the open operation state of the valve, thereby significantly reducing the current consumption compared to about 1 A of current consumed when driving a valve using a conventional driving power source. have.

As a result, the present invention can prevent the rise of the temperature of the fuel cut solenoid valve to suppress the vaporization of the liquid gas fuel, thereby improving the fuel efficiency of the vehicle by precisely controlling the amount of gas fuel supplied to the engine. .

1 is a block diagram of a fuel pump motor driving apparatus according to the prior art.
2 is a block diagram of a fuel pump motor control apparatus according to a preferred embodiment of the present invention.
Figure 3 is a flow chart illustrating a step-by-step method for controlling the fuel pump motor according to an embodiment of the present invention.

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

2 is a block diagram of a fuel pump motor control apparatus according to a preferred embodiment of the present invention.

As shown in FIG. 2, the fuel pump motor control apparatus according to the preferred embodiment of the present invention includes a motor driving means 20 for driving a fuel pump motor (hereinafter, abbreviated as a motor) 11 and a motor ( From the sensing means 30 for detecting the driving state of the 11), the valve driving means 40 for driving the fuel cut solenoid valve (hereinafter abbreviated as "valve") 12 installed in the fuel supply line and the ECU 13 And a controller 50 for controlling the driving of the motor driving means 20 and the valve driving means 40 based on the transmitted driving signal and the detection result of the sensing means 30.

And the fuel pump motor control apparatus according to a preferred embodiment of the present invention is a motor controller provided in the control unit 50 and the motor drive means 20 for 5V supply power supplied from the battery 10 via a power supply not shown And a power conversion unit 60 for converting the logic power of 5V necessary for the driving of the 23 and the driving power of about 12V necessary for driving the motor 11 and the valve 12 to each other.

In this embodiment, the motor 11 uses a BLDC motor, and in particular, will be described as using a sensorless BLDC motor.

However, the present invention is not necessarily limited thereto, and may be modified to use a BLDC motor having a sensor.

Motor driving means 20 is a motor controller for generating a motor driving signal based on the duty value of the PWM control signal applied from the motor driving unit 21, the control unit 50 for driving the motor 11 by switching the drive power source (23) and a first gate driver 22 for converting and applying the voltage level of the motor driving signal to the voltage level of the driving power source for driving the motor driving unit 21.

The motor driver 21 is a three-phase full bridge method using a first field effect transistor (hereinafter, referred to as a 'FET') element, and is applied to the motor 11. Switch the driving power of about 12V.

The motor controller 23 generates a three-phase motor driving signal having a logic power level from the power converter 60 according to the duty value of the PWM control signal of the controller 50.

The first gate driver 22 converts a three-phase motor driving signal having a logic power level into a voltage level of the driving power source for driving the motor driving unit 21 and applies it to the gate terminal of the first FET device.

The sensing means 30 includes a rotor position detector 31 and a motor for detecting the position of the rotor by using the back EMF signal appearing in each phase (u, v, w) of the motor 11 when the motor 11 is driven. And an overcurrent detector 32 that detects an overcurrent applied to the controller 11 and transmits the overcurrent to the controller 50.

Accordingly, the motor controller 23 transmits a tacho signal corresponding to the position of the rotor detected by the rotor position detector 31 to the controller 50, and the controller 50 controls the motor 11 from the taco signal. The current RPM is calculated, and the duty value of the PWM control signal is changed according to the difference between the calculated current RPM and the target RPM according to the speed control signal transmitted from the ECU 13 to control the driving of the motor 11.

In addition, when the overcurrent detecting unit 32 detects the overcurrent and transmits a detection signal to the control unit 50, the control unit 50 controls to limit the driving of the motor 11 to prevent damage and malfunction of the motor 11. do.

The valve driving unit 40 converts the FET driving signal transmitted from the valve driving unit 41 and the controller 50 driving the valve 12 by switching the driving power to the voltage level of the driving power, thereby driving the valve driving unit 41. And a second gate driver 42 for applying to.

The valve driver 41 includes a second FET device for switching the driving power of about 12V applied to the valve 12.

The second gate driver 42 applies the valve driving signal converted to the voltage level of the driving power supply to the gate terminal of the second FET element.

The controller 50 generates a FET driving signal having a logic power level when the valve driving command is received from the ECU 13, and when the preset initial driving time elapses after the valve 12 is driven, the controller 50 supplies a voltage applied to the valve 12. The PWM duty value of the FET driving signal is changed to be lowered to the preset turn-on holding voltage and transferred to the second gate driver 42.

To this end, the controller 50 includes a voltage sensing unit 51 for sensing the voltage of the driving power applied to the valve 12 from the battery 10 therein.

Of course, the voltage sensing unit 51 may be separately provided outside the control unit 50.

The initial driving time is a time at which sufficient gas fuel is filled in the fuel supply line by opening the valve 12, for example, about 10 seconds.

The turn-on sustain voltage is a voltage that must be applied to maintain the turn-on state. According to an experimental value, the turn-on sustain voltage is set to about 4 V or more, and is set to about 4 V in this embodiment.

Accordingly, in the present invention, when the initial driving time elapses after turning on the fuel cut solenoid valve using the driving power supply, the PWM duty value of the FET driving signal is changed to apply a turn-on holding voltage lower than the driving power to supply fuel. By keeping the cut solenoid valve turned on, it is possible to prevent the temperature of the fuel cut solenoid valve from rising.

 Hereinafter, a fuel pump motor control method according to a preferred embodiment of the present invention will be described in detail.

3 is a flowchart illustrating a step-by-step method of controlling a fuel pump motor according to an exemplary embodiment of the present invention.

As shown in Figure 3, the fuel pump motor control method according to an embodiment of the present invention, the power supply unit when the ignition key (IG, not shown) input signal is input in the state of receiving the constant power from the battery 10 It starts while receiving the supply power from (not shown) (S10).

As the ignition key input signal is input in step S10, the power conversion unit 60 converts the supply power into a logic power of 5V and a driving power of 12V, and converts the driving power into the first gate driver 22 and the motor driving unit ( 21, the motor 11, the valve drive unit 41 and the valve 12 is applied (S11).

Then, the controller 50 receives the speed control signal and the valve drive signal for controlling the drive of the motor 11 and the valve 12 from the ECU 13 to control the drive of the motor 11 and the valve 12. Start (S12).

Briefly describing a method of controlling motor driving, the controller 50 sets the duty value of the PWM control signal according to the target RPM based on the received speed control signal, and applies the duty value to the motor controller 23. ) Generates a three-phase BLDC motor driving signal and applies it to the gate of the first FET device provided in the motor driving unit 21.

Accordingly, when the first FET device is turned on to drive the motor 11, the motor controller 23 transmits a taco signal according to the rotor position detected from the rotor position detector 31 to the controller 50.

The controller 50 calculates the current RPM of the motor 11 from the taco signal, and changes the duty value of the PWM control signal according to the difference between the calculated current RPM and the target RPM according to the speed control signal transmitted from the ECU 13. Thereby continuously controlling the driving of the motor 11.

Meanwhile, during motor driving, the overcurrent detecting unit 32 detects an overcurrent applied to the motor 11, and if the overcurrent is detected, the controller 50 controls to limit the driving of the motor 11.

In the present embodiment, the controller 50 controls the driving of the motor 11 and the driving of the valve 12 at the same time as described above.

Referring to the driving control method of the valve in detail, the control unit 50 generates the FET driving signal of the logic power level according to the valve driving signal received in step S12 and applies it to the second gate driver 42 (S13). The second gate driver 42 converts the FET driving signal into the voltage level of the driving power supply and applies it to the gate terminal of the second FET device.

At this time, the FET driving signal has a PWM duty value of 100%.

Accordingly, the second FET device is turned on (S14) and the valve 12 is opened (S15).

On the other hand, when the valve 12 is opened, the controller 50 counts time using an internal timer.

Thus, when an initial driving time, for example, about 10 seconds has elapsed (S16), the controller 50 senses the voltage of the driving power using the voltage sensing unit 51 provided therein, so that the driving power applied to the valve 12 is reduced. The voltage is determined (S17).

The controller 50 sets a PWM duty value of the FET drive signal to maintain the actual sensed voltage of the drive power at a preset turn-on holding voltage of about 4V, and sets the FET drive signal of the set PWM duty value to the second gate driver. (42) (S18).

For example, when the voltage sensed by the voltage sensing unit 51 is 12V which is the same as the driving power supply, the controller 50 controls the PWM to maintain the voltage applied to the gate terminal of the second FET device at a turn-on holding voltage of 4V. Set the duty value to approximately 33%, which is the reference duty.

If the voltage sensed by the voltage detector 51 is 10 V lower than the driving power supply, the controller 50 sets the PWM duty value to about 40% higher than the reference duty.

On the other hand, when the voltage sensed by the voltage detector 51 is 13V higher than the driving power supply, the controller 50 sets the PWM duty value to about 30% lower than the reference duty.

By changing and setting the PWM duty value in accordance with the change of the driving power as described above, the turn-on holding voltage is continuously applied to the gate terminal of the second FET device, and the valve 12 is continuously maintained in an open operation state.

According to the current consumption test, the present invention maintains the open operation state of the valve with the turn-on holding voltage when the initial driving time elapses, and consumes about 300 mA of current, thereby consuming a current amount in the valve driving method using a conventional driving power source. Compared with about 1A, it can be seen that the current consumption can be significantly reduced.

Subsequently, the control unit 50 sets the PWM duty value of the FET driving signal according to the voltage of the driving power sensed by the voltage sensing unit 51 until the ignition key is turned off in step S19. The open operation state of (12) is maintained.

If the ignition key is turned off in step S19, the controller 50 controls to stop driving of the motor 11 and the valve 12.

Accordingly, the driving of the motor 11 and the valve 12 is terminated (S20).

Through the process as described above, the present invention by applying a turn-on holding voltage lower than the drive power supply after the initial driving time after opening the fuel cut solenoid valve to maintain the open state, the temperature of the fuel cut solenoid valve The rise can be prevented.

The scope of the present invention is not limited to the embodiments described above, but is defined by the claims, and various changes and modifications can be made by those skilled in the art within the scope of the claims. It is self evident.

10: battery 11: motor
12: Fuel Cut Solenoid Valve 13: ECU
20: motor driving means 21: motor driving unit
22: first gate driver 23: motor controller
30: detection means 31: rotor position detection unit
32: current sensing unit 40: valve driving means
41: valve driving unit 42: second gate driver
50: control unit 51: voltage detection unit
60: power conversion unit

Claims (9)

A fuel pump motor control apparatus for controlling the driving of a fuel cut solenoid valve installed in a fuel pump motor and a fuel supply line for supplying fuel pumped by the fuel pump to an engine,
Motor driving means for driving a motor for a fuel pump;
Sensing means for detecting a driving state of the motor;
Valve driving means for driving the fuel cut solenoid valve,
A control unit for controlling the driving of the motor driving means and the valve driving means based on a driving signal received from the ECU of the vehicle and a detection result of the sensing means;
And a power conversion unit for converting the supply power supplied from the power supply unit of the vehicle into logic power required for driving the motor driving means and the control unit and drive power required for driving the motor and the valve.
The valve driving means
A valve driving unit which drives the valve by switching the driving power;
And a gate driver converting a power level of the FET driving signal transmitted from the control unit into a voltage level at which the motor driving unit is driven and transmitting the voltage to the valve driving unit. The method of claim 1,
The valve driver includes a first FET element,
And the gate driver converts the FET driving signal at the logic power level into a voltage level of the driving power and applies the gate signal to the gate of the first FET device. 3. The method according to claim 1 or 2,
Further comprising a voltage sensing unit for sensing the voltage of the drive power,
The controller is configured to change the PWM duty value of the FET driving signal to maintain the voltage sensed by the voltage sensing unit at a preset turn-on holding voltage of the FET device when a predetermined initial driving time elapses after driving the valve. Fuel pump motor control device characterized in that. The method of claim 3, wherein
The motor driving means is a motor driving unit for driving the motor by switching the drive power,
A motor controller for generating a motor driving signal based on a duty value of the PWM control signal applied from the controller;
A second gate driver for converting and applying a voltage level of the motor driving signal to a voltage level of the driving power source;
The sensing means may include a rotor position detector for detecting a position of the rotor by using a counter electromotive force signal appearing on each of the motors when the motor is driven;
And an overcurrent detector for detecting an overcurrent applied to the motor and transferring the overcurrent to the controller. (a) converting the supply power into the logic power required for driving the motor driving means and the driving power required for driving the motor for the fuel pump and the fuel cut solenoid valve;
(b) receiving a speed control signal and a valve driving signal for controlling the driving of the motor and the valve from the ECU of the vehicle,
(c) controlling driving of the motor according to the speed control signal received in step (b); and
(d) performing step (c) and controlling driving of the valve based on the valve driving signal;
Step (d) is
(d1) generating a FET driving signal of the logic power level according to the valve driving signal;
(d2) converting the FET driving signal generated in step (d1) into a voltage level of the driving power source and applying the same to the gate terminal of the FET device; and
and (d3) opening the valve on the basis of the FET driving signal applied in the step (d2). The FET driving signal of claim (d2) and (d3)
A fuel pump motor control method characterized in that it is set to a PWM duty value of 100%. The method of claim 5, wherein step (d)
and (d4) maintaining a voltage of the driving power at a preset turn-on holding voltage of the FET device when a predetermined initial driving time elapses after driving the valve. Way. 8. The method of claim 7, wherein step (d4)
When the voltage level of the driving power sensed by the voltage sensing unit is lower than the turn on sustain voltage, the PWM duty value of the FET driving signal is set higher than a preset reference duty.
And if the detected voltage level of the driving power supply is higher than the turn-on holding voltage, setting the PWM duty value of the FET driving signal to be lower than the reference duty. The method according to any one of claims 5 to 8, wherein step (c)
(c1) setting a duty value of the PWM control signal according to the target RPM based on the speed control signal, and driving the motor based on the set duty value;
(c2) detecting the position of the rotor by using a counter electromotive force signal appearing on each phase of the motor when the motor is driven;
(c3) calculating a current RPM of the motor by using the position of the rotor detected in the step (c2);
(c4) controlling the driving of the motor by changing a duty value of the PWM control signal according to a difference between a current RPM calculated in the step (c3) and a target RPM according to the speed control signal;
The method of controlling the fuel pump motor, characterized in that the driving of the motor is limited when an overcurrent is applied to the motor during the motor driving based on the (c1) to (c4) step.

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