KR102532659B1 - Oil pump motor cotrol apparatus and method - Google Patents

Abstract

It relates to an oil pump motor control device and control method. mode, comparing the received target rotation speed with a preset set rotation speed and (c) selectively changing and controlling the control method of the driving motor that drives the oil pump based on the comparison result of the step (b). Noise generated during driving of the oil pump may be reduced by providing a configuration including the step of changing the control method in conjunction with the target rotational speed of the drive motor applied to the oil pump.

Description

Oil pump motor control device and control method {OIL PUMP MOTOR COTROL APPARATUS AND METHOD}

The present invention relates to an oil pump motor control device and control method, and more particularly, to an oil pump motor control device and control method for controlling a motor applied to an oil pump supplying oil to a transmission of a hybrid vehicle.

In general, a hybrid electric vehicle (Hybrid Electric Vehicle) means to drive a vehicle by efficiently combining two or more different types of power sources, and in most cases, an electric motor driven by an engine that obtains driving power using fuel and battery power Refers to a vehicle that is powered by

In response to the demand of the times to improve fuel efficiency and develop more eco-friendly products, research on hybrid vehicles is being actively conducted.

A hybrid vehicle is basically a vehicle that has an engine, a motor, a vehicle battery, and a high-voltage battery. Recently, the capacity of the high-voltage battery is made larger than that of conventional hybrid vehicles, and the high-voltage battery is charged from an external power source. A plug-in hybrid vehicle that runs in HEV mode when the high-voltage battery is discharged is being developed.

The plug-in hybrid electric vehicle (PHEV), like a conventional hybrid vehicle, is equipped with an internal combustion engine and a battery engine driven by gasoline at the same time, drives the vehicle using one or both of them, and has a large capacity. As a vehicle that can be charged with electricity by installing a high-voltage battery, it has the advantage of being able to be used continuously because it can be charged with electricity as if charging a cell phone or refueling gasoline at home or at a charging station.

The present applicant has disclosed and registered an oil pump driving device technology for hybrid and plug-in hybrid vehicles in a number of patent documents 1 and 2 below.

Meanwhile, in an automatic transmission applied to a hybrid vehicle, an oil pump is applied for supplying oil to automatic transmission parts and lubricating and cooling so that a clutch and a brake can transmit torque necessary for vehicle operation.

In order to supply oil to the automatic transmission, the oil pump must generate a certain pressure and flow rate.

Here, the hydraulic pressure and flow rate generated by the oil pump are determined by the capacity and rotational speed of the oil pump.

However, the oil pump according to the prior art has a problem in that the size increases when the capacity is increased, and the driving noise increases when the number of revolutions is increased.

For this reason, when applied to a hybrid or electric vehicle without engine noise, the noise of the oil pump is limited, which inevitably increases the capacity of the pump.

Korean Patent Registration No. 10-1044228 (published on June 27, 2011) Korean Patent Registration No. 10-1307911 (published on September 13, 2013)

An object of the present invention is to solve the above problems, and an oil pump motor control device and control for controlling a motor applied to an oil pump that forms and supplies oil to an automatic transmission applied to a hybrid vehicle at a constant hydraulic pressure and flow rate. is to provide a way

Another object of the present invention is to provide an oil pump motor control device and control method capable of reducing noise during operation of the oil pump without reducing the capacity of the oil pump and increasing the number of revolutions.

Another object of the present invention is to provide an oil pump motor control device and control method capable of reducing noise of the oil pump and optimizing the size of the oil pump.

In order to achieve the above object, the oil pump motor control device according to the present invention receives target number of revolutions and driving mode information through communication with the main control unit provided in the hybrid vehicle, and the received driving mode is the electric mode. If , the control method of the drive motor for driving the oil pump is selectively changed based on the result of comparing the received target speed with the preset set speed to control the motor drive unit to reduce noise caused by driving the oil pump. It is characterized in that it includes a control unit.

In addition, in order to achieve the above object, the oil pump motor control method according to the present invention includes (a) receiving target rotational speed and driving mode information through communication with a main control unit provided in a hybrid vehicle in a control unit; (b) comparing the received target rotation speed with a preset set rotation speed when the received driving mode is the electricity mode; and (c) driving the oil pump based on the comparison result of the step (b). and selectively changing the control method of the motor to reduce noise caused by driving the oil pump.

As described above, according to the oil pump motor control apparatus and control method according to the present invention, the control method is changed in association with the target rotational speed of the drive motor applied to the oil pump to reduce noise generated when the oil pump is driven. effect is obtained.

That is, according to the present invention, the drive of the drive motor can be controlled by selectively applying any one of the unequal pitch simulation control, maximum switching frequency control, and linear switching frequency variable control method according to the target rotation speed received from the main controller. The effect that can be obtained is obtained.

Therefore, according to the present invention, in an electric vehicle mode in which the noise of the oil pump is a problem in a hybrid vehicle, a differential pitch simulation control method is applied at high speed rotation, and a linear switching frequency variable control method is applied at low speed rotation. The effect of minimizing noise is obtained.

Accordingly, according to the present invention, the efficiency of the oil pump can be improved by optimizing the size of the oil pump instead of reducing the capacity of the oil pump and increasing the number of rotations to form a certain flow rate and pressure. is obtained

1 is a configuration diagram of an oil pump;
2 is a block diagram of an oil pump motor control device according to a preferred embodiment of the present invention;
3 is a conceptual diagram of equal pitch control and unequal pitch control;
4 is a graph illustrating signals during unequal pitch simulation control;
5 is a graph illustrating a noise reduction effect according to unequal pitch simulation control;
6 is a graph of noise measurement results according to switching frequency for each number of rotations;
7 is a flowchart illustrating a control method of an oil pump motor control device according to a preferred embodiment of the present invention step by step.

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

First, prior to explaining the configuration of an oil pump motor control device according to a preferred embodiment of the present invention, the configuration of a general oil pump will be schematically described with reference to FIG. 1 .

1 is a configuration diagram of an oil pump.

Hereinafter, terms indicating directions such as 'left', 'right', 'front', 'rear', 'upper' and 'downer' are defined as indicating each direction based on the state shown in each drawing. do.

In this specification, in order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

In addition, since each component shown in the drawings is arbitrarily shown for convenience of description, the present invention is not necessarily limited to those shown in the drawings.

The oil pump 10 may be provided as a gerotor oil pump including an internal gear 11 having teeth on an outer circumferential surface and an external gear 12 having teeth on an inner circumferential surface and internally contacting the internal gear 11.

The teeth of the internal gear 11 and the external gear 12 have teeth at regular intervals, and the interval between each tooth is constant.

So, when the rotational speed of the drive motor applied to the oil pump 10 is constantly controlled, noise of a certain frequency is generated. There was a problem that the generated noise was amplified.

If the internal gear 11 and the external gear 12 have unequal pitches, the noise can be reduced by dispersing the frequency band of the generated noise, but it is difficult to design and manufacture unequal pitch compared to the equal pitch structure, manufacturing There is a problem of rising cost.

Therefore, in the prior art, in order to minimize noise in the oil pump 10 to which the equal pitch structure is applied, the number of rotations of the oil pump 10 is limited. For this reason, it is difficult to optimize the capacity of the oil pump according to the prior art, and the size of the oil pump increases.

In addition, as the driving motor applied to the oil pump 10 moves out of the audible frequency range as the control switching frequency increases, the noise generated when the oil pump 10 is driven is reduced, while as the number of switching increases, the oil pump ( The efficiency of 10) is lowered.

In this way, as the number of rotations of the oil pump 10 and the control switching frequency have a complementary relationship with each other, the oil pump control device according to the prior art finds an optimal point by trading off the above two variables It was also controlled with a fixed switching frequency.

In order to solve this problem, the present invention varies the rotational speed within the standard of one rotation of the mechanical angle of the drive motor, thereby generating an effect as if a gear with an unequal pitch rotates, or through variable control of the linear switching frequency. Reduce noise.

As shown in FIG. 1 , when the external gear 12 of the oil pump 10 has a structure having 7 teeth, noise peaks occur in a multiplied region such as the 7th order and the 14th order.

Therefore, in order to simulate and control the unequal pitch, it is possible to remove the noise component in the frequency domain multiplied by the 7th order, 14th order, etc. tooth profile.

However, since fluctuations in rotational speed also cause fluctuations in oil pressure and flow rate, the present invention was designed to operate only in areas where noise is a problem.

That is, in a hybrid vehicle, a problem area due to noise occurs in an electric vehicle mode in which an engine is not driven and driven only by a motor.

Therefore, in the present embodiment, the unequal pitch simulation control is entered when the target rotation speed for driving the transmission in the electric vehicle mode is higher than the first preset rotation speed, and the normal control is entered in the remaining areas.

In addition, in this embodiment, the linear switching frequency is variably controlled as the control switching frequency for controlling driving of the motor when the target rotation speed for driving the transmission in the armature mode is lower than the preset second set rotation speed.

Through this, the present invention can effectively reduce noise caused by high-speed rotation and low-speed rotation in an electric vehicle mode in which noise generated when the oil pump is driven is a problem.

Next, with reference to FIG. 2, the configuration of an oil pump motor control device according to a preferred embodiment of the present invention will be described in detail.

2 is a block diagram of an oil pump motor control device according to a preferred embodiment of the present invention.

As shown in FIG. 2, the oil pump motor control device 20 according to a preferred embodiment of the present invention includes a pressure controller 21, a speed controller 22, a torque converter 23, a current controller 24, It includes an inverter 25 and a control unit 30.

In addition, the oil pump motor controller 20 according to a preferred embodiment of the present invention includes a current sensor 14 for sensing current input to each phase of the drive motor 13 and a current detected by the current sensor 14. An angle estimator 26 for estimating the rotational angle of the rotor, that is, the internal gear 11, may be further included.

The pressure controller 21 may output a compensated pressure command by receiving feedback of the reference oil pressure and the oil pressure supplied by the pumping operation of the oil pump 10 .

The speed controller 22 may output a speed command by setting the rotational speed of the drive motor 13 according to the rotational angle of the rotor estimated by the pressure command and the angle estimator 26 .

The torque converter 23 may convert the speed command into a torque value by mapping the speed command into a torque.

The current controller 24 and the inverter 25 may configure a motor driving unit that drives the driving motor 13 by applying current to the driving motor 13 .

The current controller 24 may output a current control command for controlling the current applied to the drive motor 13 according to the converted torque and the control signal of the control unit 30 .

The inverter 25 may output a PWM type drive signal to drive the drive motor 13 by supplying current to each phase of the drive motor 13 based on the current control command.

The control unit 30 is communicatively connected to the main control unit (not shown) of the hybrid vehicle through CAN communication, and can control driving of each device according to a control signal received from the main control unit.

Here, the control unit 30 selectively applies any one of unequal pitch simulation control, maximum switching frequency control, and linear switching frequency variable control method according to the target rotation speed received from the main control unit to include current or rotor speed commands. It is possible to control the current controller 24 by generating a control signal that

For example, the control unit 30 uses a differential pitch simulation control method when the target rotation speed is set at a high speed of 3000 RPM or higher, such as a first set rotation speed set in advance, in an electric vehicle mode setting state in which an electric motor provided in the hybrid vehicle is driven and driven. It can be controlled to drive the drive motor 13.

In addition, in the electric vehicle mode setting state, the control unit 30 uses a linear switching frequency variable control method to drive the drive motor 13 when the target rotation speed is set to be lower than the first set rotation speed, for example, at a low speed rotation of 1500 RPM or less. can be controlled to drive.

In addition, the control unit 30 may set the engine driving mode for driving the engine provided in the hybrid vehicle or set the electric vehicle mode when the target rotation speed is the middle speed rotation between the first set rotation speed and the second set rotation speed. The driving motor 13 may be controlled to be driven by a maximum switching frequency control method using a preset maximum switching frequency according to the number of revolutions.

3 is a conceptual diagram of equal pitch control and unequal pitch control, FIG. 4 is a graph illustrating a signal during unequal pitch simulation control, and FIG. 5 is a graph illustrating a noise reduction effect according to unequal pitch simulation control.

In (a) of FIG. 3, the case of driving the equal pitch gear at a constant speed is illustrated, and in (b) of FIG. 3, the case of driving the equal pitch gear at a random speed is illustrated.

In (a) of FIG. 4, a graph is illustrated as a result of measuring the vane position of the rotor and the noise generated accordingly, and in (b) of FIG. 4, the vane position and current or rotor speed command and rotor speed are illustrated. there is.

5 shows a graph of the result of measuring the basic noise generated when the equal pitch gear is driven at a constant speed and the measurement result of the noise generated when controlling the unequal pitch simulation by applying the RPM change rate to 5%, 7%, and 9%. has been

That is, when the equal pitch gear is driven at a constant speed, for example, 600 RPM, as shown in FIG. The speed remains the same.

On the other hand, as shown in (b) of FIG. 3, if one rotation of the mechanical angle of the rotor is divided into four unequal parts, the rotation speed of each divided area is set by changing to 585 RPM, 590 RPM, 610 RPM, 615 RPM, etc. , the angles of each divided region may be different from each other.

At this time, the sum of all the fluctuating rates should be constant at 600 RPM.

As shown in (a) of FIG. 4, noise is generated according to the vane position of the rotor.

Therefore, as shown in (b) of FIG. 4, the control unit 30 generates a current or rotor speed command to vary within a certain range according to the vane position of the rotor, so that the actual speed of the rotor is based on the reference speed. It fluctuates by increasing or decreasing the standard.

As shown in FIG. 1, when seven teeth are formed on the external gear 12 of the rotor, it can be seen that noise peaks occur in areas multiplied by the 7th order and 14th order from the basic noise shown in FIG. .

Therefore, when the rotation speed is varied between a maximum of 630 RPM and a minimum of 570 RPM based on one revolution of the rotor by applying an RPM variation rate of ±5% based on the 600 RPM, it can be confirmed that the measured noise is reduced compared to the basic noise.

In addition, it can be seen that the measured noise is further reduced as the RPM fluctuation rate is increased to ±7% and ±9%.

As described above, according to the present invention, noise due to high-speed rotation of the driving motor can be controlled by generating a current or rotor speed command to which an RPM variation rate is applied in an unequal pitch simulation control method according to a target rotation speed.

Meanwhile, the control unit 30 may linearly change and control the switching frequency when the driving motor 13 rotates at a low speed.

In general, the switching frequency is set to a specific frequency value in association with the rotational speed of the drive motor 13 .

For example, if the rotation speed of the drive motor 13 is 2000 RPM or more, the switching frequency is set to the maximum frequency within the settable range, for example, 16 kHz, and if the rotation speed of the drive motor 13 is 500 RPM or less, the switching frequency is set to the minimum. It may be set to a frequency, for example 4 kHz.

Accordingly, the control unit 30 may control the switching frequency to be linearly varied within the range of the maximum frequency and minimum frequency in association with the target rotational speed during low-speed rotation of the drive motor 13 .

For example, FIG. 6 is a graph of a noise measurement result according to a switching frequency for each number of revolutions.

6 (a) to (c) show the results of measuring noise generated when switching frequencies of about 4 kHz, 8 kHz, and 16 kHz are applied when the target rotation speed is 1000 RPM, 2000 RPM, and 3000 RPM, respectively. .

As shown in (a) of FIG. 6 , when the target rotation speed is 1000 RPM, it can be confirmed that the noise reduction effect increases as the switching frequency increases from 4 kHz to 8 kHz and 16 kHz.

On the other hand, as shown in (b) and (c) of FIG. 6, when the target rotation speed is 2000 RPM or more, the noise reduction effect according to the change in switching frequency cannot be confirmed.

As described above, the present invention can effectively reduce noise generated when the oil pump is driven by controlling the switching frequency to be linearly variable in conjunction with the target rotational speed during low-speed rotation of the driving motor.

On the other hand, the control unit 30 may control the oil pump 10 to be driven using the maximum switching frequency in conjunction with the target rotation speed when the target rotation speed is at mid-speed rotation in the electric vehicle mode or when the engine driving mode.

Next, referring to FIG. 7, a control method of an oil pump motor control device according to a preferred embodiment of the present invention will be described in detail.

7 is a flowchart illustrating a control method of an oil pump motor control device according to a preferred embodiment of the present invention step by step.

When the ignition switch (not shown) provided in the hybrid vehicle is turned on in step S10 of FIG. 7, the controller 30 receives power from the battery and starts operating, and each device provided in the oil pump motor control device 20 initialize

Subsequently, the control unit 30 communicates with the main control unit of the hybrid vehicle through CAN communication, and receives target rotational speed of the drive motor 13 that drives the oil pump 10 and driving mode information of the vehicle.

In step S12, the control unit 30 checks whether the received driving mode is the electric vehicle mode.

If, as a result of the inspection in step S12, the engine drive mode is not the electric vehicle mode, the process proceeds to step S30 below to generate a control signal to drive the drive motor 13 in the maximum switching frequency control method.

On the other hand, as a result of the inspection in step S12, in the case of the electric car mode, the control unit 30 controls by changing the control method according to the target rotational speed.

That is, in step S14, the control unit 30 checks whether the target rotational speed is a low-speed rotation equal to or less than the second preset rotational speed, for example, 1500RPM or less.

If, as a result of the inspection in step S14, the target rotational speed is 1500 RPM or less, the control unit 30 calculates the switching frequency by the target rotational speed * correction coefficient (S16).

Then, the control unit 30 interlocks the calculated switching frequency with the target rotational speed and linearly varies it between a variable minimum frequency, for example, 4 kHz and a maximum frequency, for example, 16 kHz, so that the driving motor ( 13) is controlled to drive (S18).

As such, the control unit 30 generates a control signal including a current or rotor speed command according to a linearly variable switching frequency, and the current controller 24 is supplied to the drive motor 13 according to the control signal. The drive motor 13 is driven by controlling the current.

On the other hand, if the target rotational speed exceeds the second set rotational speed as a result of the inspection in step S14, the control unit 30 checks whether the target rotational speed is equal to or greater than the first preset rotational speed, for example, 3000 RPM (S20).

If, as a result of the inspection in step S20, the target rotation speed is 3000 RPM or more, the control unit 30 generates a control signal to drive the drive motor 13 by the unequal pitch simulation control method (S22).

At this time, the control unit 30 generates a current or rotor speed command to irregularly change the RPM in the RPM variation range by applying an RPM variation rate according to the vane position of the rotor, and the current controller 24 generates a current or rotor speed command according to the control signal. The drive motor 13 is driven by controlling the current supplied to the drive motor 13 .

On the other hand, as a result of the inspection in step S20, when the target rotational speed exceeds the second set rotational speed and is less than the first set rotational speed, the control unit 30 controls the maximum switching frequency using the maximum switching frequency preset according to the target rotational speed In this way, the driving motor 13 is controlled to be driven (S30).

In the process of performing steps S18, S22, and S30 described above, the control unit checks whether the driving of the hybrid vehicle is terminated (S40), and repeatedly performs steps S12 to S40 until the driving is terminated.

Meanwhile, when the driving ends as a result of the inspection in step S40, the controller 30 stops and ends driving of each device provided in the oil pump motor control device 20.

Through the process as described above, the present invention can reduce the noise generated when the oil pump is driven by changing the control method in conjunction with the target rotational speed of the driving motor applied to the oil pump.

That is, the present invention selectively applies any one method among unequal pitch simulation control, maximum switching frequency control, and linear switching frequency variable control method according to the target rotation speed received from the main controller to control the driving of the drive motor. .

Therefore, in the present invention, in an electric vehicle mode in which the noise of the oil pump is a problem in a hybrid vehicle, the differential pitch simulation control method is applied at high speed rotation and the linear switching frequency variable control method is applied at low speed rotation to reduce noise caused by driving the oil pump. can be minimized.

Due to this, the present invention can improve the efficiency of the oil pump by optimizing the size of the oil pump instead of reducing the capacity of the oil pump and increasing the number of rotations to form a certain flow rate and pressure.

Although the invention made by the present inventors has been specifically described according to the above embodiments, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention.

The present invention is applied to an oil pump motor control device and control method technology that reduces noise generated when an oil pump is driven by changing a control method in conjunction with a target rotational speed of a drive motor applied to an oil pump.

10: oil pump
11: internal gear 12: external gear
13: drive motor 14: current sensor
20: oil pump motor controller
21: pressure controller 22: speed controller
23: torque converter 24: current controller
25: inverter 26: angle estimator
30: control unit

Claims (6)

An oil pump motor control method for controlling a drive motor of an oil pump to supply oil to a transmission applied to a hybrid vehicle,
(a) receiving target number of revolutions and driving mode information through communication with a main control unit provided in a hybrid vehicle by a control unit;
(b) comparing the received target rotation speed with a preset set rotation speed when the received driving mode is the electricity mode; and
(c) selectively changing the control method of the driving motor for driving the oil pump based on the comparison result of step (b) to control noise caused by driving the oil pump to be reduced;
In the step (c), as a result of the comparison in the step (c1), when the target speed rotates at a high speed equal to or higher than the preset first set speed, the control unit applies the RPM change rate according to the vane position of the rotor applied to the oil pump. Controlling the drive of the drive motor with an unequal pitch simulation control method; and
(c2) As a result of the comparison in step (b), when the target rotation speed is lower than the second set rotation speed set to be lower than the first set rotation speed, the switching frequency is linearly variable in the minimum and maximum frequency ranges. An oil pump motor control method comprising the step of controlling the driving of the driving motor by a linear switching frequency variable control method. delete The method of claim 1, wherein step (c)
(c3) As a result of the comparison in step (b), when the target rotational speed exceeds the second set rotational speed and is less than the first set rotational speed, the maximum switching frequency preset by the control unit according to the target rotational speed is used. An oil pump motor control method further comprising the step of controlling the driving of the driving motor by a switching frequency control method. According to claim 1,
In the step (c1), the control unit generates a control signal including a current or rotor speed command to irregularly change the RPM within the RPM change rate range,
In the step (c2), the control unit calculates the switching frequency by multiplying the target rotational speed and the correction coefficient, and linearly varies the calculated switching frequency in a variable minimum and maximum frequency range in association with the target rotational speed. An oil pump motor control method characterized in that for generating a control signal. According to claim 1,
(d) if the driving mode received in step (a) is the engine driving mode, controlling the driving of the driving motor by the maximum switching frequency control method using the maximum switching frequency preset according to the target rotation speed by the control unit. Oil pump motor control method further comprising. An oil pump motor control device for controlling a driving motor of an oil pump to supply oil to a transmission applied to a hybrid vehicle using the oil pump motor control method according to any one of claims 1 and 3 to 5 ,
Target rotational speed and driving mode information are received through communication with the main controller provided in the hybrid vehicle, and when the received driving mode is electricity mode, based on the result of comparing the received target rotational speed with the preset set rotational speed and a control unit controlling the motor driving unit to selectively change a control method of a driving motor that drives the oil pump to reduce noise caused by driving the oil pump.

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