KR102324762B1 - System and method for control of hybrid vehicle - Google Patents

Abstract

A hybrid vehicle control system is disclosed. engine and motor; a clutch selectively connecting/disconnecting the rotation shaft of the engine and the rotation shaft of the motor; a transmission connected to a rotation shaft of the engine and the motor; an electric oil pump supplying oil to the clutch and the transmission; an independent flow control valve for increasing the amount of oil supplied to the clutch among the oil supplied from the electric oil pump in an open state and decreasing it in a closed state; and a controller that determines the rotational speed of the electric oil pump and the state of the independent flow control valve based on whether the clutch is slip-controlled and the temperature of the clutch.

Description

Hybrid vehicle control system and method

The present invention relates to a hybrid vehicle control system and method, and more particularly, to control the amount of oil supplied to a clutch by controlling an electronic oil pump and an independent flow control valve based on slip control of the clutch and the temperature of the clutch. It relates to a hybrid vehicle control system and method capable of being used.

The use of non-polluting energy is becoming increasingly important these days as the problem of environmental pollution on the earth is getting more serious.

In particular, the problem of air pollution in large cities is getting serious day by day, and exhaust gas from automobiles is one of the main causes.

In this way, in order to solve the problem of exhaust gas and provide fuel efficiency improvement, eco-friendly vehicles including hybrid vehicles, plug-in hybrid vehicles, and electric vehicles have been developed and operated.

An eco-friendly vehicle has power composed of an engine and a motor, and is driven by appropriately using power generated from combustion of the engine and power generated from rotation of the motor mediated by electric energy stored in a battery, respectively.

In eco-friendly vehicles, a transmission mounted electric device (TMED) type transmission in which a drive motor and a transmission are connected is commonly applied.

In an eco-friendly vehicle, an engine clutch is installed between an engine and a drive motor to transmit engine power to a drive shaft.

However, when the power of the motor does not satisfy the driver's demand for power in an eco-friendly vehicle, the TMED system satisfies the driver's demand by using the engine power through the slip of the clutch. At this time, the clutch temperature rises due to slip, and when the temperature rises to the limit temperature, there is a problem that the slip control cannot be maintained any longer.

The matters described as the background art above are only for improving the understanding of the background of the present invention, and should not be taken as acknowledging that they correspond to the prior art already known to those of ordinary skill in the art.

KR 10-0844567

An object of the present invention is to provide a hybrid vehicle control system and method in which the amount of oil supplied to the clutch can be adjusted by controlling the electronic oil pump and the independent flow control valve based on the clutch slip control and the clutch temperature. as a technical task.

The present invention as a means for solving the above technical problem,

engine and motor;

a clutch selectively connecting/disconnecting the rotation shaft of the engine and the rotation shaft of the motor;

a transmission connected to a rotation shaft of the engine and the motor;

an electric oil pump supplying oil to the clutch and the transmission;

an independent flow control valve for increasing the amount of oil supplied to the clutch among the oil supplied from the electric oil pump in an open state and decreasing it in a closed state; and

and a controller that determines the rotation speed of the electric oil pump and the state of the independent flow control valve based on whether the clutch is slip-controlled and the temperature of the clutch.

In one embodiment of the present invention, the controller may open the independent flow control valve when the clutch is slip-controlled and the clutch temperature is greater than a preset first reference temperature.

In one embodiment of the present invention, the controller may adjust the electric oil pump to a maximum speed.

In one embodiment of the present invention, the controller sets the target speed of the electric oil pump to a maximum speed and controls the electric oil pump to follow the target speed, wherein the actual speed of the electric oil pump is the target speed When following , the independent flow control valve may be opened.

In an embodiment of the present invention, the controller may block the independent flow control valve when the actual speed of the electric oil pump does not follow the target speed.

In one embodiment of the present invention, the controller is configured to include the independent flow control valve when the actual speed of the electric oil pump tracks the target speed, and the oil flow rate required by the transmission is smaller than the flow rate currently available to be supplied to the transmission can be opened.

In one embodiment of the present invention, the controller is configured to: When the actual speed of the electric oil pump tracks the target speed and the oil flow rate required by the transmission is greater than or equal to the flow rate currently available to the transmission, the independent flow rate The control valve can be shut off.

In an embodiment of the present invention, the controller is configured to block the independent flow control valve when the clutch is in a slip-controlled state and the clutch temperature is less than or equal to a preset second reference temperature that is less than the first reference temperature. can

In one embodiment of the present invention, the controller adjusts the speed of the electric oil pump to a preset basic speed, wherein the basic speed is a preset rotational speed in consideration of lubrication of the transmission without considering cooling of the clutch can be

The present invention as another means for solving the above technical problem,

An engine, a motor, a clutch selectively connecting/disconnecting the rotation shaft of the engine and the rotation shaft of the motor, a transmission connected to the engine and the rotation shaft of the motor, and an electric oil pump supplying oil to the clutch and the transmission, and the electric oil A method for controlling a hybrid vehicle, comprising: an independent flow control valve for increasing an amount of oil supplied to the clutch from among oil supplied from a pump in an open state and decreasing it in an open state, the method comprising:

determining whether to control slip of the clutch;

comparing the clutch temperature with a preset first reference temperature when the clutch is slip-controlled; and

and opening the independent flow rate control valve when the clutch temperature is greater than the first reference temperature.

In an embodiment of the present invention, the opening may include operating the electric oil pump at a maximum speed.

In an embodiment of the present invention, the step of opening may include: setting a target speed of the electric oil pump to a maximum speed and controlling the electric oil pump to follow the target speed; and

and opening the independent flow control valve when the actual speed of the electric oil pump follows the target speed.

In an embodiment of the present invention, the opening may further include blocking the independent flow control valve when the actual speed of the electric oil pump does not follow the target speed.

In one embodiment of the present invention, in the opening process, when the actual speed of the electric oil pump tracks the target speed, and the oil flow rate required by the transmission is smaller than the flow rate currently supplyable to the transmission, the independent flow rate The control valve can be opened.

In one embodiment of the present invention, in the opening process, when the actual speed of the electric oil pump tracks the target speed, and the oil flow rate required by the transmission is greater than or equal to the flow rate currently available to the transmission, the Independent flow control valves can be shut off.

An embodiment of the present invention further includes the step of shutting off the independent flow control valve when the clutch is in a slip-controlled state and the clutch temperature is less than or equal to a preset second reference temperature that is less than the first reference temperature. can do.

In one embodiment of the present invention, the step of shutting off includes adjusting the speed of the electric oil pump to a preset basic speed, wherein the basic speed prevents lubrication of the transmission without considering cooling of the clutch. It may be a preset rotation speed in consideration.

According to the hybrid vehicle control system and method, when an additional cooling flow is required due to slip control of the clutch, the amount supplied to the clutch may be increased by controlling the electronic oil pump and the independent flow control valve.

In addition, according to the hybrid vehicle control system and method, it is possible to improve the performance of the control system and the drivability of the vehicle by preventing the deterioration of the performance of the control system due to the overtemperature condition of the clutch in advance.

1 is a block diagram illustrating a hybrid vehicle control system according to an embodiment of the present invention.
2 is a flowchart illustrating a hybrid vehicle control method according to an embodiment of the present invention.

Hereinafter, a hybrid vehicle control system and method according to various embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram illustrating a hybrid vehicle control system according to an embodiment of the present invention.

Referring to FIG. 1 , a hybrid vehicle control system according to an embodiment of the present invention includes an engine 11 , a clutch 15 , a motor 17 , a transmission 19 , and an electronic oil pump (EOP) ( 21 ), an independent flow control valve 23 , and a controller 100 .

The engine 11 may be connected to the motor 17 by a clutch 15 , and the shafts of the engine 11 and the motor 17 may be connected to the transmission 19 . Although not shown, a fly wheel may be disposed between the engine 11 and the clutch 15 to reduce vibration and rotational vibration caused by the reciprocating motion of the piston of the engine 11 , and the motor 17 . A second clutch, a dual clutch or an Auto Manual Transmission (AMT), may be disposed between and the transmission 19 .

A hybrid starter generator (HSG) 13 for igniting fuel in a cylinder provided in the engine 11 may be connected to the rotation shaft of the engine 11 in a pulley method or a gear method. The HSG 13 operates as a motor to start the engine 11 or operates as a generator when the engine 11 is driven to generate an output while maintaining the start-on of the hybrid vehicle to charge the battery. generate electrical energy

The clutch 15 is disposed between the engine 11 and the motor 17 to receive a control signal from the controller 100 and selectively connect the engine 11 and the motor 17 according to the driving mode of the hybrid vehicle. / can be separated.

The motor 17 is operated by an electric motor and a generator. When the hybrid vehicle operates in the electric vehicle mode (EV mode), the motor 17 is driven to operate the vehicle. In the hybrid mode, the engine 11 and the rotation shaft of the motor 17 are connected by a clutch to the engine 11 . ) and the torque of the motor 17 may be transmitted to the wheels of the vehicle through the transmission 19 .

In particular, when the output torque of the motor 17 is smaller than the required torque, an operation that satisfies the required torque through the slip mode operation in which the power of the engine 11 is provided through the slip of the clutch 15 may be performed. An object of the present invention is to efficiently cool the heat generated in the clutch during the sleep mode operation.

For cooling of the clutch 15 , an electronic oil pump (EOP) 21 supplies cooling oil to the clutch 15 . The oil supplied by the electronic oil pump 21 may also be applied to the cooling of the motor 17 .

The electromagnetic oil pump 21 provides lubricating oil of the transmission 19 as well as cooling oil provided to the clutch 15 or the motor 17 . The main use of the actual electronic oil pump 21 is to provide lubricating oil for the transmission 19, but the clutch 15 and the motor 17 are disposed close to the transmission 19 and a refrigerant for cooling is required. In consideration of this, a part of the lubricating oil is applied by the motor 17 as a refrigerant of the transmission 19.

The oil output from the electronic oil pump 21 is branched into two lines and provided to the transmission 19 and the clutch 15 (or the motor 17), respectively, and a supply line provided to the clutch 15 for cooling purposes. is provided with an independent flow control valve 23 .

The independent flow control valve 23 may determine the amount of cooling flow supplied to the clutch 15 according to its operating state. For example, when the independent flow control valve 23 is in the open state, the amount of cooling oil can be increased by opening the line supplied to the clutch 15, and when the independent flow control valve 23 is in the blocked state In this case, it is possible to reduce the amount of cooling oil by blocking the line supplied to the clutch 15 .

The controller 100 may determine the rotational speed of the electronic oil pump 21 and the open/closed state of the independent flow control valve 23 based on whether the clutch 15 is slip-controlled and the temperature of the clutch 15 .

A detailed operation of the controller 100 as a subject performing a vehicle control method according to an embodiment of the present invention will be described with reference to FIG. 2 .

2 is a flowchart illustrating a hybrid vehicle control method according to an embodiment of the present invention.

1 and 2 , the hybrid vehicle control method according to an exemplary embodiment of the present invention may start with the step S11 of the controller 100 determining whether to control the slip. In the example of FIG. 1 , the controller 100 is illustrated as receiving a separate signal for determining whether to control slip from the outside (eg, a higher-level controller), but the controller 100 operates the clutch 15 In the case of the direct controlling subject, it is possible to determine whether to perform sleep control by itself.

Next, when it is determined that the clutch 15 is in a slip-controlled state, the controller 100 detects the operation state of the independent flow control valve 23 ( S12 ). Step S12 is to check whether the flow rate of the cooling oil provided to the clutch 15 is increased by the independent flow control valve 23 being opened through the control of the independent flow control valve 23 before the execution This is an optional step for

Next, if the independent flow control valve 23 is blocked, the controller 100 compares the temperature of the clutch 15 with a preset first reference temperature (S13). The first reference temperature may be arbitrarily set as a reference temperature to which cooling oil should be supplied to prevent overtemperature of the clutch 15 .

When the temperature of the clutch 15 is lower than the preset first reference temperature, the controller 100 determines the operation state of the independent flow control valve 23 to be a shut-off state (S20) and sends the clutch 15 and the motor 17 to the clutch 15 and the motor 17. It is possible to reduce the supplied cooling flow. Conversely, when the temperature of the clutch 15 is higher than the preset first reference temperature, the operation state of the independent flow control valve 23 is determined to be an open state (S17) to increase the flow rate of the cooling oil provided to the clutch 15. can

Meanwhile, before performing step S17, steps S14 to S16 may be selectively performed.

More specifically, the controller 100 sets the target speed of the EOP 21 to the maximum speed and controls the EOP 21 so that the EOP 21 tracks the target speed (S14), and the controller 100 sets the EOP It can be checked whether the actual speed of (21) follows the target speed (ie, the maximum speed) (S15). If the actual speed of the EOP 21 does not follow the target speed, the controller 100 makes it impossible for the EOP 21 to rotate at the maximum speed, so that the cooling oil of the clutch 15 and the lubricating oil of the transmission 19 It is appropriate to reduce the cooling flow rate supplied to the clutch 15 by blocking the operation state of the independent flow rate control valve 23 (S20) by determining that it is difficult to supply a flow rate sufficient to provide all of them.

When the actual speed of the EOP 21 follows the target speed (maximum speed), it is determined that oil can be supplied to both the transmission 19 and the clutch 15, and the operation state of the independent flow control valve 23 is opened ( S17) It is possible to increase the amount of cooling flow supplied to the clutch 15 .

On the other hand, step S16 is a step for additionally confirming the transmission required flow rate. The controller 100 compares the required flow rate of the transmission 19 with the flow rate that can be supplied to the transmission 19 (S16), and when the required flow rate of the transmission 19 is smaller than the flow rate that can be supplied to the transmission 19, independent flow rate adjustment By blocking the operation state of the valve 23 ( S20 ), the amount of cooling oil supplied to the clutch 15 can be reduced and the amount of lubricating oil supplied to the transmission 19 can be properly maintained. Conversely, when the required flow rate of the transmission 19 is smaller than the flow rate that can be supplied to the transmission 19, the controller 100 opens the operating state of the independent flow rate control valve 23 (S17).

In step S16 , the required flow rate of the transmission 19 may be determined by the input speed, torque, gear stage, and line pressure of the transmission 19 . The required flow rate of the transmission 19 may increase as power increases in proportion to the input speed and torque. In addition, since the required flow rate of the transmission 19 differs from the torque and speed for each clutch according to the gear stage, the gear stage may be considered. Since the required flow rate of the transmission 19 is determined according to the line pressure, the flow rate supplied to the transmission 19 may also be considered.

In addition, in step S16 , the flow rate that can be supplied to the transmission 19 is a flow rate that can be supplied to the transmission 19 when the independent flow control valve 23 is open (on), and the control line pressure and the automatic transmission oil (ATF) : Automatic Transmission Fluid) It can be determined by the temperature. Here, the control line pressure may be controlled together with the speed of the EOP 21 by the controller 100 in consideration of the real-time driver's requested torque, the speed of the transmission 19, whether there is a shift, and the ATF temperature. The flow rate that can be supplied to the transmission 19 is obtained by subtracting the cooling flow rate supplied to the clutch 15 and the motor 17 from the total cooling flow rate.

On the other hand, if it is determined in step S12 that the independent flow control valve 12 is already in the on state, the controller 100 determines whether the temperature of the clutch 15 is lower than or equal to a preset second reference temperature (S18) . Here, the second reference temperature is a temperature smaller than the first reference temperature, and is a temperature that does not interfere with operation even if the flow rate of the cooling oil of the clutch 15 is reduced, that is, a temperature that can block the independent flow control valve 12 .

In step S18 , if the temperature of the clutch 15 is lower than or equal to the second reference temperature preset, the controller 100 blocks the independent flow control valve 23 to reduce the flow rate of the cooling oil provided to the clutch 15 . can be decreased (S20).

The controller 100 may adjust the target speed of the EOP 21 to a preset basic speed before shutting off the independent flow control valve 23 . Here, the basic speed means a rotational speed capable of supplying an oil flow rate considering only the lubrication of the transmission 19 without considering the cooling of the clutch 15 and the motor 17 .

Meanwhile, if it is determined in step S18 that the temperature of the clutch 15 is higher than or equal to the second reference temperature, the controller 100 performs steps S14 for supplying cooling oil to the clutch 15 as described above. to S17) may be performed.

As described above, in the hybrid vehicle control system and method according to an embodiment of the present invention, when an additional cooling flow is required due to the slip control of the clutch, the electronic oil pump and the independent flow control valve are controlled to be supplied to the clutch. amount can be increased.

In addition, the hybrid vehicle control system can improve the performance and vehicle drivability of the control system by preventing deterioration in performance of the control system due to an overtemperature condition of the clutch in advance.

Although illustrated and described in relation to specific embodiments of the present invention in the above, it is understood that the present invention can be variously improved and changed without departing from the technical spirit of the present invention provided by the following claims. It will be apparent to those of ordinary skill in the art.

11: Engine 13: Hybrid Starter Generator
15: clutch 17: motor
19: Transmission 21: Electronic oil pump
23: independent flow control valve 100: controller

Claims (17)

engine and motor;
a clutch selectively connecting/disconnecting the rotation shaft of the engine and the rotation shaft of the motor;
a transmission connected to a rotation shaft of the engine and the motor;
an electric oil pump supplying oil to the clutch and the transmission;
an independent flow control valve for increasing the amount of oil supplied to the clutch among the oil supplied from the electric oil pump in an open state and decreasing it in a closed state; and
a controller for determining the rotational speed of the electric oil pump and the state of the independent flow control valve based on whether the clutch is slip-controlled and the temperature of the clutch;
The controller is
opening the independent flow control valve when the clutch is in a slip-controlled state and the clutch temperature is greater than a preset first reference temperature;
The controller is
Setting the target speed of the electric oil pump as a maximum speed, controlling the electric oil pump to follow the target speed, and opening the independent flow control valve when the actual speed of the electric oil pump follows the target speed Hybrid vehicle control system, characterized in that. delete delete delete The method according to claim 1,
The controller is
and closing the independent flow control valve when the actual speed of the electric oil pump does not follow the target speed. The method according to claim 1,
The controller is
and opening the independent flow rate control valve when the actual speed of the electric oil pump tracks the target speed and the oil flow rate required by the transmission is less than the flow rate currently available to the transmission. 7. The method of claim 6,
The controller is
Hybrid vehicle control, characterized in that the actual speed of the electric oil pump tracks the target speed, and when the oil flow rate required by the transmission is greater than or equal to the flow rate currently available to the transmission, the independent flow control valve is blocked. system. The method according to claim 1,
The controller is
and when the clutch is in a slip-controlled state and the clutch temperature is less than or equal to a preset second reference temperature that is less than the first reference temperature, the independent flow control valve is shut off. 9. The method of claim 8,
The controller is
The hybrid vehicle control system according to claim 1, wherein the speed of the electric oil pump is adjusted to a preset basic speed, wherein the basic speed is a preset rotation speed in consideration of lubrication of the transmission without considering cooling of the clutch. An engine, a motor, a clutch selectively connecting/disconnecting the rotation shaft of the engine and the rotation shaft of the motor, a transmission connected to the engine and the rotation shaft of the motor, and an electric oil pump supplying oil to the clutch and the transmission, and the electric oil A control method for a hybrid vehicle comprising an independent flow control valve for increasing an amount of oil supplied to the clutch from among the oil supplied from a pump in an open state and decreasing it in an open state, the method comprising:
determining whether to control slip of the clutch;
comparing the clutch temperature with a preset first reference temperature when the clutch is slip-controlled; and
and opening the independent flow control valve when the clutch temperature is greater than the first reference temperature.
The opening step is
setting the target speed of the electric oil pump as a maximum speed and controlling the electric oil pump to follow the target speed; and
and opening the independent flow control valve when the actual speed of the electric oil pump tracks the target speed. delete delete 11. The method of claim 10,
The opening step is
and blocking the independent flow control valve when the actual speed of the electric oil pump does not follow the target speed. 11. The method of claim 10,
The opening process is
and opening the independent flow rate control valve when the actual speed of the electric oil pump tracks the target speed and the oil flow rate required by the transmission is smaller than the flow rate currently available to the transmission. 15. The method of claim 14,
The opening process is
Hybrid vehicle control, characterized in that the actual speed of the electric oil pump tracks the target speed, and when the oil flow rate required by the transmission is greater than or equal to the flow rate currently available to the transmission, the independent flow control valve is blocked. Way. 11. The method of claim 10,
and when the clutch is in a slip-controlled state and the clutch temperature is less than or equal to a preset second reference temperature that is less than the first reference temperature, shutting off the independent flow rate control valve. Way. 17. The method of claim 16,
The blocking step is
and adjusting the speed of the electric oil pump to a preset basic speed, wherein the basic speed is a preset rotational speed in consideration of lubrication of the transmission without considering cooling of the clutch. Way.

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